LOAD FLOW SIMULATION OF 7-BUS-IEEE NETWORK

ampITS APPLICATION IN 400kV GRID NETWORK OF MSETCL SYSTEM

Department Of Electrical EngineeringNagpur

2010

AIM Of The project helliphellip

In

To determine the POWER FLOW SIMULATION USING IEEE-7 BUS NETWORK amp ITS APPLICATION IN 400 KV GRID NETWORK OF MSETCL(Maharashtra State Electricity Transmission Co Ltd) SYSTEM USING POWER WORLD SIMULATOR

For POWER FLOW SIMLATION N-R METHOD ADOPTED

AC POWER FLOW SIMULATION TO EVALUATE TOTAL LOAD IN TERMS OF ACTIVE POWER FLOW IN MW REACTIVE POWER FLOW MVARTOTAL GENERATION IN MW MVAR VOLTAGE ANGLE OF ALL BUSES REACTIVE REQUIREMENT OF 7-BUS SYSTEM

AFTER OUTAGES ON TYPICAL TIE LINES AGAIN Case is SIMULATED amp WORKS OUT LOADING ON THE AVAILABLE LINES IN TERMS OF MW MVAR amp VOLTAGE STABILITY ACCORDINGLY

ABOVE APPLICATION IMPLEMENTED IN MSETCL NETWORK ampAGAIN RUN THE POWER WORLD SIMULATOR amp SIMULATES THE POWER FLOW

Methodology adopted

Simulation tool used power world simulator 90 version

7 bus 138 kv network consider for power flow simulation

Newtons-Raphson Method adopted for power simulation due to fast amp accuracy in simulation

Contents

1) Objectives of load flow analysis2) How to analyze power flow in power network

3) Why N-R Method

4) Flow-Chart of N-R Method

5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus

7) Load flow output a) Buswise Voltages amp angle

b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power

Mvar d) Active amp reactive loss

ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo

Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages

o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

AIM Of The project helliphellip

In

To determine the POWER FLOW SIMULATION USING IEEE-7 BUS NETWORK amp ITS APPLICATION IN 400 KV GRID NETWORK OF MSETCL(Maharashtra State Electricity Transmission Co Ltd) SYSTEM USING POWER WORLD SIMULATOR

For POWER FLOW SIMLATION N-R METHOD ADOPTED

AC POWER FLOW SIMULATION TO EVALUATE TOTAL LOAD IN TERMS OF ACTIVE POWER FLOW IN MW REACTIVE POWER FLOW MVARTOTAL GENERATION IN MW MVAR VOLTAGE ANGLE OF ALL BUSES REACTIVE REQUIREMENT OF 7-BUS SYSTEM

AFTER OUTAGES ON TYPICAL TIE LINES AGAIN Case is SIMULATED amp WORKS OUT LOADING ON THE AVAILABLE LINES IN TERMS OF MW MVAR amp VOLTAGE STABILITY ACCORDINGLY

ABOVE APPLICATION IMPLEMENTED IN MSETCL NETWORK ampAGAIN RUN THE POWER WORLD SIMULATOR amp SIMULATES THE POWER FLOW

Methodology adopted

Simulation tool used power world simulator 90 version

7 bus 138 kv network consider for power flow simulation

Newtons-Raphson Method adopted for power simulation due to fast amp accuracy in simulation

Contents

1) Objectives of load flow analysis2) How to analyze power flow in power network

3) Why N-R Method

4) Flow-Chart of N-R Method

5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus

7) Load flow output a) Buswise Voltages amp angle

b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power

Mvar d) Active amp reactive loss

ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo

Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages

o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Methodology adopted

Simulation tool used power world simulator 90 version

7 bus 138 kv network consider for power flow simulation

Newtons-Raphson Method adopted for power simulation due to fast amp accuracy in simulation

Contents

1) Objectives of load flow analysis2) How to analyze power flow in power network

3) Why N-R Method

4) Flow-Chart of N-R Method

5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus

7) Load flow output a) Buswise Voltages amp angle

b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power

Mvar d) Active amp reactive loss

ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo

Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages

o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Contents

1) Objectives of load flow analysis2) How to analyze power flow in power network

3) Why N-R Method

4) Flow-Chart of N-R Method

5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus

7) Load flow output a) Buswise Voltages amp angle

b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power

Mvar d) Active amp reactive loss

ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo

Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages

o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo

Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages

o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages

o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

What is already known What has to be calculated

1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

How to analyze power flow in power Network

To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts

upto 900

bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus

locationbull Long and short lines terminating --- can solve a system with a long to

on the same bus short ratio at any bus of 10000001

bull Long radial type of system ----- solves a wider range of such problems

bull Acceleration Factor ------ None required

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Flow chart of N-R Method

Form bus admittance matrix YBUS

Assume bus voltagesEp0 where p=12hellipnampp=s

Set iteration countK=0

Calculate Real amp Reactive bus powers

Calculated difference between Scheduled ampcalculated powers

Determine Maximum change in power max del pk and Max Qk

T est for convergence Calculate line flows and power flows

Equal

Or less

Calculate Bus currents

Calculate elements for jacobian

Calculate new bus voltages

Greater

Advance Iteration

count

k+1k

Replace epk by epk+1and fpk

by fpk+1 where

p=12hellipnampp=s

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Steps for calculation For the calculation of powerflow it is must to find out the

impedance between two buses Impedances given in fig is in ohm per kmso we have to

multiply that by the distance between two busesso the required impedance is obtained

In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

per unit calculation the data required for the powerflow analysis should be in

unit formfor that all data such as voltagesline impedance etc

The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit

Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

IEEEndash7 Bus System Load Flow Analysis

Using Powerworld

slack

1

2

3 4

5

6 7

100 pu

102 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVAA

MVA

A

MVA A

MVA

A

MVA

A

MVA

A

MVA

49 MW

49 MW

46 MW 46 MW 57 MW 57 MW

48 MW

48 MW

74 MW 73 MW

38 MW

38 MW

7 MW

50 MW

50 MW 25 MW 25 MW

0 MW

0 MW

A

MVA

25 MW 25 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

100A

MVA

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Table 10 Areawise Generation amp Loads in MegaWatts

Area Generation in MW

Load in MW

Top -Area1 35204 4000

Left Area2 2500 2000

Right Area3 20023 2000

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

From Number

To Number Circuit Status

ResistanceR

pu

ReactanceX

pu

Line ChargingB

puLine LimitLim A MVA

1 2 1 Closed 0005 005 05 65

1 3 1 Closed 002 024 005 65

2 3 1 Closed 0015 018 004 80

3 4 1 Closed 00025 003 002 222

2 4 1 Closed 0015 018 004 100

2 5 1 Closed 001 012 003 100

7 5 1 Closed 0005 006 004 200

4 5 1 Closed 002 024 005 60

2 6 1 Closed 0005 006 005 200

6 7 2 Closed 002 024 005 200

6 7 1 Closed 002 024 005 200

Line Characteristics of 7-bus system

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Table 30Bus Types

Number Name Area Name Type

1 1 Top PV

2 2 Top PV

3 3 Top PQ

4 4 Top PV

5 5 Top PQ

6 6 Left PV

7 7 Right Slack

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Bus types

In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

POWER FLOW OUTPUT

Power Flow simulation of 7-bus IEEE System is as followsBus Flows

BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top

GENERATOR 1 9554 743R 958

TO 2 2 1 4940 -1098 506 78

TO 3 3 1 4614 1841 497 76

BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top

GENERATOR 1 15000 2806R 1526

LOAD 1 4000 2000 447

TO 1 1 1 -4928 -4239 650 100

TO 3 3 1 89 1996 519 65

TO 4 4 1 3807 1892 425 43

TO 5 5 1 7354 1425 749 75

TO 6 6 1 -023 -268 27 1

BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top

LOAD 1 15000 4000 1552

TO 1 1 1 -4567 -1805 491 76

TO 2 2 1 -4750 -1948 513 64

TO 4 4 1 -5683 -247 569 26

BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top

GENERATOR 1 10651 096R 1065

LOAD 1 8000 3000 854

TO 2 2 1 -3781 -1993 427 43

TO 3 3 1 5691 144 569 26

TO 5 5 1 741 -1055 129 21

BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top

LOAD 1 13000 4000 1360

TO 2 2 1 -7302 -1115 739 74

TO 4 4 1 -739 575 94 16

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

TO 7 7 1 -4960 -3460 605 30

BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left

GENERATOR 1 25000 -1089R 2502

LOAD 1 20000 000 2000

TO 2 2 1 023 -272 27 1

TO 7 7 1 2488 -408 252 13

TO 7 7 2 2488 -408 252 13

BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right

GENERATOR 1 20023 3251R 2028

LOAD 1 20000 000 2000

TO 5 5 1 4977 3240 594 30

TO 6 6 1 -2477 005 248 12

TO 6 6 2 -2477 005 24

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Bus No

Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar

1138 105 1449 443 9554 743

2 138 104 14352 317 40 20 150 2806

3138 099799 137723 -141 150 40

4 138 1 138 -043 80 30 10651 096

5138 101803 140488 -152 130 40

6 138 104 14352 318 200 0 250 -1089

7 138 104 14352 0 200 0 20023 3251

Voltage Magnitude and Phase angle

COMMENTS

Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld

After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other

buses

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Power Transfer amp MW Mvar Losses

From Number

To Number Circuit Status

MW From

Mvar From

MVA From

Lim MVA

MW Loss

Mvar Loss

1 2 1 Closed 494 -11 506 65 012 -5337

1 3 1 Closed 461 184 497 65 047 036

2 3 1 Closed 479 20 519 80 039 048

2 4 1 Closed 381 189 425 100 026 -101

2 5 1 Closed 735 143 749 100 052 31

2 6 1 Closed -02 -27 27 200 0 -541

3 4 1 Closed -568 -25 569 222 008 -102

4 5 1 Closed 74 -106 129 60 002 -48

7 5 1 Closed 498 324 594 200 017 -22

6 7 1 Closed 249 -41 252 200 011 -403

6 7 2 Closed 249 -41 252 200 011 -403

From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows

Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus

Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW

from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of

Power flow study is possible only after simulation of power flows

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Conclusion

Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows

the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines

with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the

losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS

slack

1

2

3 4

5

6 7

100 pu

098 pu

104 pu104 pu

104 pu

100 pu105 pu

A

MVA

A

MVA

A

MVA A

MVA

A

MVA

A

MVA

47 MW

47 MW

49 MW 49 MW 49 MW 49 MW

53 MW

52 MW

110 MW 109 MW

44 MW

44 MW

21 MW

0 MW

0 MW 0 MW 0 MW

50 MW

50 MW

A

MVA

0 MW 0 MW

96 MW

150 MW

250 MW 200 MW

150 MW

40 Mvar

80 MW 30 Mvar

130 MW

40 Mvar

40 MW

20 Mvar

107 MW

200 MW

0 Mvar200 MW

0 Mvar

AGC ON

AGC ON

AGC ON

AGC ON

AGC ON

97A

MVA

81A

MVA

119A

MVA

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Simulation output OUTAGE ON Tie Line 5 to Line7

Bus No

Nom kV

PU Volt

Before Outage

Volt (kV)

After Outage

Volt (kV)

Before OutageAngle in

(Deg)

After OutageAngle in

(Deg)Load MW

Load Mvar

Before outage

Gen Mvar

After Outage

Gen Mvar

Gen MW

1 138 105 1449 1449 443 -043 743 778 9582

2 138 104 14352 14352 317 -161 40 20 2806 6391 15029

3 138 099 137723 137703 -141 -667 150 40

4 138 100 138 138 -043 -582 80 30 096 1693 10679

5 138 098 140488 135598 -152 -876 130 40

6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250

7 138 104 14352 14352 0 0 200 0 3251 -542 20012

From above Table It concludes that

line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows

Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus

Change in Voltage angle also observed at Bus3 due to Load bus

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Simulation OutputMwMvar Loss After Outage On line5-7

(Removing Transmission Line)

From Number

To Number Circuit

Before MW on

Line

AfterMW on

Line

BeforeMvar on

Line

After Mvar on

Line MVA

From

BeforeMW

Loss

AfterMW

LossMvar Loss

AfterTripping

Mvar Loss Status

1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed

1 3 1 461 492 184 185 526 047 052 036 101 Closed

2 3 1 479 527 20 20 563 039 045 048 128 Closed

2 4 1 381 442 189 188 48 026 033 -101 -018 Closed

2 5 1 735 1099 143 456 119 052 132 31 1281 Closed

2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed

3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed

4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed

7 5 1 498 0 324 0 0 017 0 -22 0 Open

6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed

6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)

From Table following are the observations of load flow study after tie line

Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted

on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss

also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7

suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line

On Line 4-5 Loading in terms of MW Mvar also increased l

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

MSETCL 400 KV POWER NETWORK OVERVIEW

Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur

In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations

In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and

MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Real Time Active Power Flow on 8- Bus System MSETCL

Dt05-09-2009

Bus400 Kv Line

MSETCL400 Kv Line

Length Km

Line LoadingMW

ICT Loading MW Mvar

1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84

2 2-3 Akola-Koradi 151 391 Akola 464 31

3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34

4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10

5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134

6 7-4 Bhadravati-Chandrapur IIIIIIIV

18 840 Solapur 182 60

7 6-3 Bhilai--Koradi 150 454

8 5-8 Parli-Solapur 273 467

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses

Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained

Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses

Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below

i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD

1 BHSWL2

2 AKOLA

3 KORADI 4 CHANDRAPUR

5 PARLI

6 BHILAI 7 BHADRAVATI

100 pu

098 pu

101 pu102 pu

099 pu

100 pu098 pu

83A

MW

A

MVAA

MVA

A

MVA

A

MVA

267A

MW

126A

MW

A

MVA

144A

MW

8 MW

8 MW

187 MW 189 MW 91 MW 91 MW

38 MW

39 MW

270

143 MW

332 MW332 MW

454 MW

58 MW 34 Mvar

304 MW

-10 Mvar

246 MW136 Mvar

46 MW 3 Mvar

-242 MW

122 MW

195 MW 92 Mvar

179 MW

84 Mvar

83A

MW

267A

MW

267A

MW

267A

MW

8 SOLAPUR

A

MVA

182 MW

6 Mvar

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Bus Mismatches

Number NameArea Name Type

Mismatch MW

1 Bhusawal Top PQ 0

2 AKOLA Top PQ 0

3 KORADI Top PV 0

4 CHANDRAPUR Top Slack 0

5 PARLI Top PQ 0

6 BHILAI Left PQ (Gens at Var Limit) 0

7 BHADRAVATI Right PQ (Gens at Var Limit) 0

8 SOLAPUR Top PQ 0

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

LINE Characteristics of 8-bus MSETCL System

From Number From Name To Number To Name Circuit StatusResista

nceReactan

ce

Line Charging

1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05

1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005

2 AKOLA 3 KORADI 1 Closed 0015 018 004

3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002

4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005

4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004

7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004

7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004

5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0

6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

From Name To Name CircuitMW

From Mvar From MVA From

Lim MVA

of MVA Limit (Max) MW Loss

Mvar Loss

1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788

1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834

2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118

3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073

4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171

4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171

4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073

7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588

7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588

5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96

6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147

Power Flow Simulation 8-Bus 400 Kv MSETCL

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Comments Power flow on Line in terms of MW amp

Mvar amp simulated the results It gives the output in terms of MW Mvar losses

Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power

It indicates Reactive compensation is required at Bhusawal end

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Bus Records Voltage Magnitude amp Angle

Bus Records

Number NameArea Name

Nom kV PU Volt

Volt (kV)

Angle (Deg)

Load MW

Load Mvar

Gen MW

Gen Mvar

1 1 Bhusawal Top 400 09769 39076 -643 179 84

2 2 AKOLA Top 400 098584 394338 -667 464 31

3 3 KORADI Top 400 1 400 -267 58 34 195 9193

4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415

5 5 PARLI Top 400 098472 393889 -284 246 136

6 6 BHILAI Left 400 102453 40981 506 122 34 454 100

7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100

8 8 SOLAPUR Top 400 097796 391183 -584 182 6

COMMENTS

It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the

Buses 34 6 amp 7

After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus

found low as compared to other buses This is due to Load buses no generator is connected to the particular buses

Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

Conclusion For the calculation of powerflow it is must to find out the impedance

between two buses The solution to the power flow problem begins with identifying the known

and unknown variables in the system The known and unknown variables are dependent on the type of bus

The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)

When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required

No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System

The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

FUTURE SCOPE amp ITS APPLICATIONS

Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning

The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations

Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs

Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur

REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly

1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower

flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967

BOOKS George L kusic Computer aided power system analysissecond

edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system

INFORMATION FROM ALDCNagpur