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International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 – 6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME 344 UNDERSTANDING OPERATION OF SHUNT CAPACITORS AND OLTC FOR TRANSMISSION LOSS REDUCTION Dr. M. P. Sharma Sarfaraz Nawaz AEN, RVPNL, Jaipur Assoc. Prof., EE Deptt., SKIT, Jaipur ABSTRACT This paper presents an understanding operation of shunt capacitor banks and OLTC in various power system conditions for reactive power control in power transmission system to reduce transmission losses, power system elements loading and voltage control. This paper also presents efficient use of existing shunt capacitor banks for voltage-var control in power transmission system in order to avoid installation of new devices allowing economy of operation. The procedure has been simulated to the Rajasthan power transmission system model having 750 buses, 6800MWsystem load and 3200MVAR capacity shunt capacitor banks installed at various 33KV and 11KV load buses in order to verify its effectiveness. Rajasthan power system has been modeled using Mi-Power power system analysis software designed by the M/s PRDC Bangalore. Results of tests conducted on the model system in various possible field conditions are presented and discussed. Simulation results compared with that obtaining using existing methods for operations of shunt capacitor banks & OLTC attach with power transformers for reactive power and voltage control are presented to show the potential of application of the proposed methods to power system economical operation. (I) INTRODUCTION Rapid rise in load growth in the Rajasthan system led to fast expansion of the Rajasthan Electrical Network. Total transmission system network at the end of financial year for last three years is placed at Table-1. INTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY (IJEET) ISSN 0976 – 6545(Print) ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), pp. 344-357 © IAEME: www.iaeme.com/ijeet.asp Journal Impact Factor (2013): 5.5028 (Calculated by GISI) www.jifactor.com IJEET © I A E M E

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International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

344

UNDERSTANDING OPERATION OF SHUNT CAPACITORS AND

OLTC FOR TRANSMISSION LOSS REDUCTION

Dr. M. P. Sharma Sarfaraz Nawaz

AEN, RVPNL, Jaipur Assoc. Prof., EE Deptt., SKIT, Jaipur

ABSTRACT

This paper presents an understanding operation of shunt capacitor banks and OLTC in

various power system conditions for reactive power control in power transmission system to

reduce transmission losses, power system elements loading and voltage control. This paper

also presents efficient use of existing shunt capacitor banks for voltage-var control in power

transmission system in order to avoid installation of new devices allowing economy of

operation. The procedure has been simulated to the Rajasthan power transmission system

model having 750 buses, 6800MWsystem load and 3200MVAR capacity shunt capacitor

banks installed at various 33KV and 11KV load buses in order to verify its effectiveness.

Rajasthan power system has been modeled using Mi-Power power system analysis software

designed by the M/s PRDC Bangalore. Results of tests conducted on the model system in

various possible field conditions are presented and discussed. Simulation results compared

with that obtaining using existing methods for operations of shunt capacitor banks & OLTC

attach with power transformers for reactive power and voltage control are presented to show

the potential of application of the proposed methods to power system economical operation.

(I) INTRODUCTION

Rapid rise in load growth in the Rajasthan system led to fast expansion of the

Rajasthan Electrical Network. Total transmission system network at the end of financial year

for last three years is placed at Table-1.

INTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING

& TECHNOLOGY (IJEET)

ISSN 0976 – 6545(Print) ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), pp. 344-357

© IAEME: www.iaeme.com/ijeet.asp Journal Impact Factor (2013): 5.5028 (Calculated by GISI) www.jifactor.com

IJEET

© I A E M E

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

345

Table-1: Total transmission network at the end of financial year

Particulars 31-3-09 31-3-10 31-3-11

400 kV S/S

(Nos/MVA)

4(2955) 7(3900) 9(4895)

400 kV

Lines

(ckt kms)

1358 1945 2660

220 kV S/S

(Nos/MVA)

62(11855) 66(12955) 74(15405)

200 kV

Lines

(ckt kms)

9321 10067 10662

132 kV S/S

(Nos/MVA)

280(14151) 292(15871) 310(18174)

132 kV

Lines

(ckt kms)

12776 13193 13852

(II) TRANSMISSION LOSSES WITHIN STATE

For Rajasthan Power System, recorded peak load (MW) & reactive power demand

and transmission losses within the state in the past few years have been tabulated at Table-2.

Table-2: Transmission lossess within state

FY 2007-

08

2008-

09

2009-

10

2010-

11

Recorded peak

load (MW)

5564 6101 6859 7442

Load Reactive

Power

Demand

(MVAR)

4173 4575 5144 5581

%Transmission

losses

4.61% 4.34% 4.43 4.40

To compensate the load reactive power demand, capacitor banks have been installed

at 33 kV (at 132/33 kV GSS’s), 11 kV (at 33/11 kV GSS’s) and LT voltage levels. As on

31.3.2011, 3200 MVAR capacity capacitors banks have been installed in the Rajasthan

system at 33 kV voltage level. Rating of most of capacitor Banks is 5.43 MVAR at 33 kV

voltage level. At 220 kV & 132 kV substations, for voltage and power factor control two

devices are available:-

• On Load Tap Changers provided on EHV Transformers

• Shunt capacitor banks installed at 33 kV voltage level

When to operate OLTC & when the capacitor bank is big question??. Understanding and

coordinated operation of OLTC and capacitor banks results reduction in system losses,

improved voltage profile and reduce MVA loading of transformers & transmission lines.

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

346

To understand impact of operation of OLTC & capacitor banks in different operating

conditions on voltage profile, system losses and MVA Loading of transformer and

transmission lines some simulation studies have been carried and presented. Rajasthan power

system has been selected to carry out the simulation studies. Rajasthan power system has

been represented up to 33 kV voltage level using the Mi-Power software. Load and capacitor

banks have been lumped at 33 kV buses at 220 kV and 132 kV sub-stations. All transmission

lines above 132 kV voltage level and all 400/220 kV, 220/132 kV & 132/33 kV

transformers have been represented. 132 kV GSS Lalsot has been selected to show the effect

of OLTC operation and shunt capacitor banks operation in different operating

conditions. 132 kV sub-station Lalsot is presently connected to 220 kV sub-station Dausa via

35 kM long 132 kV S/C line. Details of power system Equipment's installed at 132kV Lalsot

are as follows:-

Transformers capacity

• 132/33kV 1x40/50 MVA Transformer: Total No. of taps :1-5-9, 10 % impedance

• 132/33kV 1x20/25 MVA Transformer: Total No. of taps :1-5-9, 10 % impedance

Capacitor Banks Capacity

• 1x5.43MVAR, 33kV Voltage Shunt Capacitor Bank-1

• 1x5.43MVAR, 33kV Voltage Shunt Capacitor Bank-2

• 1x5.43MVAR, 33kV Voltage Shunt Capacitor Bank-3

132kV S/C Dausa- Lalsot line: 35kM

(III) CASE STUDY-1: BENEFITS OF SHUNT CAPACITOR BANKS

Power plots of load flow study with 45 MW, 0.80 PF load at 33 kV bus (505) is

placed at LFS Plots-1. Under this condition reactive power drawal of 33 kV Bus(505) from

Grid is approximately 20 MVAR. Power plots of LFS with 4th

1x5.43 MVAR, 33 kV

Capacitor Bank at 33 kV Bus(505) while other conditions are remain unchanged is placed at

LFS Plots-2.

Fig. :1 LFS Plot1: With three Capacitor Banks at 33 kV Bus ( 505)

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

347

Fig. 2: LFS Plot 2: With four Capacitor Banks at 33 kV Bus ( 505)

Impact of 4th

Shunt Capacitor Banks on reactive power flow, transmission losses,

system voltage and system element loading have been analyzed.

• Impact on Reactive Power Flow

Reactive flow

on

With three

Capacitor Banks

With four

Capacitor Banks

132/33 kV

Transformers

20.99 MVAR 16.34 MVAR

132kV line 22.76 MVAR 17.79 MVAR

220/132kV

Transformers

91.09 MVAR 85.09 MVAR

• Impact on voltage profile

Particulars With three

Capacitor

Banks

With four

Capacitor

Banks

33 kV bus voltage 29.21 kV 29.55 kV

132 kV bus voltage 117.76 kV 118.93 kV

220 kV bus voltage 214.52 kV 214.81 kV

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

348

• Impact on Transformers and transmission lines loading

Particulars With three

Capacitor Banks

With four

Capacitor

Banks

132/33 kV transformers

loading

50.05 MVA 48.17 MVA

132 kV line loading 51.37 MVA 49.28 MVA

220/132 kV transformers

loading

168.51 MVA 165.19 MVA

• Impact on Transmission losses

Particulars With three

Capacitor

Banks

With four

Capacitor

Banks

Total losses in 132kV

network (Line+Tranf.)

1.06 MW 0.96 MW

• Saving in transmission losses in 132kV network

due to fourth Capacitor bank : 0.10 MW

• Saving in transmission losses in 220kV & above

network due to fourth capacitor bank: 2.5x0.1

• Saving in transmission losses in 132kV network

due to fourth Capacitor bank : 0.10 MW

• Saving in total transmission losses due to fourth capacitor bank: 0.10 + 0.25 = 0.35 MW

• Yearly Energy Saving: 30.66 LUs

• Saving in terms of rupees: 30.66x2.0 = Rs. 61.32 Lacs/annum

This study indicates that With 4th

unit of shunt capacitor bank

• Voltages of 220 kV, 132 kV & 33 kV buses have been improved

• Loading on transformers & transmission line has been reduced.

• Transmission losses have been reduced.

Therefore, capacity of Capacitor Banks at load Bus should be comparable to Bus

reactive Power Demand in order to reduce the system losses and system elements

loading.

(IV) CASE STUDY-2: CONTROL OF HIGH VOLTAGE BY CAPACITOR BANKS

VS OLTC OPERATION

Power plots of LFS with 33 MW, 0.80 PF load at 33 kV bus(505) is placed at LFS

plots-3. Under this condition voltage of 33 kV bus(505) is above the 5% of nominal voltage.

This 33 kV bus high voltage can be reduced either by switching off one capacitor bank or

decreasing the transformer ratio with the help of OLTC. Power plots of LFS for voltage

control through one capacitor bank switching OFF and transformer tap ratio reduction is

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

349

placed at LFS plots-4 & 5 respectively. Impact of 33 kV Bus (505) voltage control through

Capacitor Bank switching (Case-1) vs OLTC operation (Case-2) on reactive power flow,

transmission losses, system voltage and system element loading have been analyzed.

• Impact on Reactive Power Flow

Reactive flow

on

Capacitor Bank

operation

OLTC

Operation

132/33 kV

Transformers

12.99 MVAR 8.12 MVAR

132kV line 13.30 MVAR 8.42 MVAR

220/132kV

Transformers

37.12 MVAR 31.62 MVAR

• Impact on voltage profile

Particulars Capacitor

Bank

operation

OLTC

Operation

33 kV bus voltage 34.34 kV 33.34 kV

132 kV bus voltage 132.70 kV 133.72 kV

220 kV bus voltage 224.13 kV 224.38 kV

• Impact on Transformers and transmission lines loading

Particulars Capacitor

Bank

operation

OLTC

Operation

132/33 kV

transformers loading

35.59 MVA 34.07 MVA

132 kV line loading 35.64 MVA 34.19 MVA

220/132 kV

transformers loading

109.34

MVA

107.55

MVA

• Impact on Transmission losses

Particulars Capacitor

Bank

operation

OLTC

Operation

Total losses in 132kV

network (Line+Tranf.)

0.42 MW 0.38 MW

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

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• Saving in transmission losses in 132kV network in Case-2 as compared to Case-1: 0.04

MW

• Saving in transmission losses in 220kV & above network in Case-2 as compared to

Case-1:

= 2.5 x 0.04 MW = 0.10 MW

• Saving in total transmission losses in Case-2 as compared to Case-1: 0.14 MW

• Yearly Energy Saving in Case-2 as compared to Case-1 for four hours: 2.04 LUs

• Saving in terms of rupees: 2.04 x2.00 = Rs 4.08 lacs/annum

This study indicates that under lagging power factor of a bus, control of high bus voltage

through switching OFF capacitor Bank instead of OLTC operation results:

• Increase the reactive power flow on Transformers and Transmission lines

• Increase the MVA loading on transformers & transmission lines.

• Reduction in 132 kV & 220 kV voltages which may be already low in some system

conditions.

• Increase the total system losses which results loss of revenue.

Fig. 3: LFS Plot 3: Base Case with high 33 kV Bus (505) Voltage

Fig. 4: LFS Plots 4: Control of high 33 kV Bus(505) voltage through switched off one

Capacitor Bank

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

351

Fig. 5 : LFS Plot 5: Control of high 33 kV Bus(505) voltage by reduction in

Transformers Tap ratio from 1.04 PU to 1.0 PU

Therefore, in lagging power factor condition, high voltage of a Bus should be

regulated through OLTC operation instead of switching OFF the Capacitor Banks in

order to reduce the system losses and system elements loading.

(V) CASE STUDY-3: OPTIMUM UTILIZATION OF CAPACITOR BANKS

Power plots of LFS with 45 MW, 0.80 PF load at 33 kV bus(505) is placed at LFS

plots-6. Under this condition

• Voltage of 33 kV bus(505) is 27.74 kV

• Reactive power flow on 132 kV transformers is 22.24 MVAR

• 132/33 kV Transformers tap position is 1.0 PU

• Capacitor banks are injecting 13.65 MVAR against the 16.29 MVAR connected

capacity.

Now transformer ratio of 132/33 kV transformers connected to 33 kV Bus(505) is increased

from 1.0 PU (Case-1) to 1.05 PU (1/0.95) (Case-2) while other system conditions remain

unchanged. Power plots of LFS with increase transformers ratio is placed at LFS plots-7.

Impact of rise in transformer tap ratio on reactive power flow, transmission losses, system

voltage and system element loading have been analyzed.

• Impact on Reactive Power Flow

Reactive flow on Transformer

Ratio:1.00PU

Transformer

Ratio:1.05PU

Output of Capacitor

Banks connected to

Bus(505)

13.65 MVAR 15.48 MVAR

132/33 kV

Transformers

23.94 MVAR 21.57 MVAR

132kV line 24.48 MVAR 21.98 MVAR

220/132kV

Transformers

84.89 MVAR 81.92 MVAR

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

352

• Impact on voltage profile

Particulars Transformer

Ratio:1.00PU

Transformer

Ratio:1.05PU

33 kV bus voltage 30.22 kV 32.18 kV

132 kV bus voltage 125.46 kV 126.01 kV

220 kV bus voltage 226.10 kV 226.23 kV

• Impact on Transformers and transmission lines loading

Particulars Transformer

Ratio:1.00PU

Transformer

Ratio:1.05PU

132/33 kV

transformers loading

51.13 MVA 50.05 MVA

132 kV line loading 52.21 MVA 51.02 MVA

220/132 kV

transformers

loading

165.01 MVA 163.42 MVA

• Impact on Transmission losses

Particulars Transformer

Ratio:1.00PU

(Case-1)

Transformer

Ratio:1.05PU

(Case-2)

Total losses

in 132kV

network

(Line+Tranf.)

1.12 MW 1.05 MW

• Saving in transmission losses in 132kV network in Case-2 as compared to Case-1: 0.07

MW

• Saving in transmission losses in 220kV & above network in Case-2 as compared to

Case-1:

= 2.5 x 0.07 MW = 0.175 MW

• Saving in total transmission losses in Case-2 as compared to Case-1: 0.245 MW

• Yearly Energy Saving in Case-2 as compared to Case-1 for four hours: 3.57 LUs

• Saving in terms of rupees: 3.57 x2.00 = Rs 7.14 lacs/annum

This study indicates that rise in transformer tap ratio

under low load bus voltage condition increase the output of the connected capacitor banks

which results:

• Decrease the reactive power flow on Transformers and Transmission lines

• Decrease the MVA loading on transformers & transmission lines.

• Increase the 33 kV, 132 kV & 220 kV voltages which may be already low in some

system conditions..

• Decrease the total system losses.

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

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Fig. 6 :LFS Plot 6: 1.0 PU tap ratio of 132/33 kV Transformers connected to 33 kV

Bus(505)

Fig. 7 : LFS Plot 7: 1.05 (1/0.95) PU tap ratio of 132/33 kV Transformers connected to

33 kV Bus(505)

Therefore, load bus voltage should be maintained near to nominal with the variation of

transformer ratio using OLTC unit for optimum utilization of Shunt Capacitor Banks

to reduce the system losses.

(VI) CASE STUDY-4: EFFECT OF OLTC OPERATION OF 220/132 KV

TRANSFORMERS ON TRANSMISSION LOSSES

Power plots of LFS with total 148 MW, 0.80 PF load connected to 33 kV Buses No.

501, 502, 504 and 505 is placed at LFS plots-8. Under this condition

• Voltages of 33 kV buses is poor, therefore, output of capacitor banks is below to their

rated capacity

• Voltages of 132 kV buses is also poor

• Tap position of 220/132 kV transformers is 1.0 PU

Now transformer ratio of 220/132 kV transformers connected to 132 kV Bus (101) is

increased from 1.0 PU (Case-1) to 1.04 PU (1/0.96) (Case-2) while other system conditions

remain unchanged. Power plots of LFS with increase transformers ratio is placed at LFS

plots-9. Impact of rise in 220/132 kV transformer tap ratio on reactive power flow,

transmission losses, system voltage and system element loading have been analyzed.

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

354

• Impact on Reactive Power Flow

Reactive flow on Transformer

Ratio:1.00PU

Transformer

Ratio:1.04PU

Reactive power

injection by the

Connected

Capacitor banks at

various 33 Buses

35.97

MVAR

40.57 MVAR

220/132kV

Transformers

112.21 MVAR 100.94 MVAR

• Impact on voltage profile

Particulars Transformer

Ratio:1.0PU

Transformer

Ratio:1.04PU

132 kV bus voltage 126.66 kV 136.06 kV

220 kV bus voltage 213.41 kV 213.96 kV

• Impact on Transformers and transmission lines loading

Particulars Transformer

Ratio:1.00PU

Transformer

Ratio:1.04PU

220/132 kV

transformers

loading

188.97 MVA 182.00 MVA

• Impact on Transmission losses

Particulars Transformer

Ratio:1.00PU

(Case-1)

Transformer

Ratio:1.04PU

(Case-2)

Total losses in

132kV network

of 220 kV GSS

5.50 MW 4.78 MW

• Saving in transmission losses in 132kV network in Case-2 as compared to Case-1: 0.72 MW

• Saving in transmission losses in 220kV & above network in Case-2 as compared to Case-1:

= 2.5 x 0.72 MW = 1.80 MW

• Saving in total transmission losses in Case-2 as compared to Case-1: 2.52 MW

• Yearly Energy Saving in Case-2 as compared to Case-1 for four hours: 36.79 LUs

• Saving in terms of rupees: 36.79 x2.00 = Rs 73.58 lacs/annum

This study indicates that rise in transformer tap ratio

of 220/132 kV transformers under low voltage condition increase the output of the connected

capacitor banks which results:

• Decrease the reactive power flow on Transformers and Transmission lines

• Decrease the MVA loading on transformers & transmission lines.

• Increase the 33 kV, 132 kV & 220 kV voltages which may be already low in some system

conditions..

• Decrease the total system losses.

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

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Fig. 8: LFS Plot8: 1.0 PU Transformer ratio of 220/132 kV Transformers connected

to 132 kV Bus(101)

Fig. 9 : LFS Plot 9: 1.04 PU (1/0.96) Transformer ratio of 220/132 kV Transformers

connected to 132 kV Bus(101)

Therefore, voltage of 132 kV Bus at 220 kV sub-stations should be maintained near to

nominal with the operation of OLTC to increase the output of connected capacitor

banks to reduce the system losses and system elements loading.

(VII) CONCLUSION

Understanding operation of Shunt Capacitor Banks and OLTC in different operating

conditions results:-

• Reduction of reactive power flow on transmission lines and transformers

• Reduction of loading of transmission lines and transformers

• Improve the transmission system voltage

• Reduction of transmission system losses

Therefore, understanding operations should be performed on Capacitor Banks and OLTC

attached with transformers in different operating conditions. Capacitor banks are the means to

compensate load reactive power demand to the bus (the load bus) to which these are

connected so as to restrict flow of reactive power from the sending bus to the load bus.

Therefore, in order to reduce the system losses and system elements loading

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

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• Capacity of Capacitor Banks at load Buses should be comparable to Bus reactive Power

Demand

• The shunt capacitors are required to be kept ‘ON’ till the reactive component of the load

(which is generally inductive) is more than the reactive power injected by the shunt

capacitors i.e. power factor of the load bus is lagging.

• Output of the capacitor banks is squarely proportional to system voltage where capacitor

bank is connected therefore load bus voltage should be maintained near to nominal for

maximum utilization of connected capacitor banks.

REFERENCE

1. R.F. Cook, “Optimizing the application of Shunt Capacitor for Reactive Volt-Ampere

Control and Loss Reduction” IEEE Trans. On Power Delivery, Vol. 80, Aug. 1999,

pp:430-444

2. B. V. Vidhute, Dr. H. P. Inamdar, and S.A. Deokar, “Maximum Loss Reduction by

Optimal Placement of Capacitors on a Distribution System” Power India Conference,

2008, IEEE, pp: 1-3.

3. Bei Gou “Optimal Capacitor Placement for improving Power quality, Power

Engineering Society Summer Meeting, IEEE, 1999, PP-488-492.

4. H. Kim, S-K. You, “Voltage Profile Improvement by capacitor Placement and control in

unbalanced distribution Systems using GA”, IEEE power Engineering Society Summer

Meeting, 1999, Vol. 2, pp. 18-22.

5. J. B. V. SUBRAHMANYAM, “Optimal Capacitor Placement in Unbalanced Radial

Distribution Networks” Journal of Theoretical and Applied Information Technology,

Vol6. No1. (pp 106 - 115)

6. M. H. Shwehdi, A. Mantawi , S. Selim, A “Capacitor Placement In Distribution

Systems, A New Formulation”

7. IEEE Bolgona Power Tech. Conference, June 23-26, 2003 Chun Wang and Hao Zhong

Cheng, “Reactive power optimization by plant growth simulation algorithm,” IEEE

Trans. on Power Systems, Vol.23, No.1, pp. 119-126, Feb. 2008

8. Suresh Kamble, and Dr. Chandrashekhar Thorat, “Characterization of Voltage Sag Due

to Balanced and Unbalanced Faults in Distribution Systems”, International Journal of

Electrical Engineering & Technology (IJEET), Volume 3, Issue 1, 2012, pp. 197 - 209,

ISSN Print : 0976-6545, ISSN Online: 0976-6553.

9. Om Prakash Mahela and Sheesh Ram Ola, “Optimal Placement and Sizing of HT Shunt

Capacitors for Transmission Loss Minimization and Voltage Profile Improvement: The

Case of Rrvpnl Power Grid”, International Journal of Electrical Engineering &

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ISSN Online: 0976-6553.

10. S.Neelima and Dr. P.S.Subramanyam, “Effect of Load Levels on Sizing and Location of

Capacitors in Distribution Systems”, International Journal of Electrical Engineering &

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ISSN Online: 0976-6553.

International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –

6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME

357

BIOGRAPHIES

Dr. M. P. Sharma received the B.E. degree in Electrical Engineering

in 1996 Govt. Engineering College, Kota, Rajasthan and M.Tech

degree in Power Systems in 2001 and Ph.D. degree in 2009 from

Malaviya Regional Engineering College, Jaipur (Now name as MNIT).

He is presently working as Assistant Engineer, Rajasthan Rajya Vidhyut

Prasaran Nigam Ltd., Jaipur. He is involved in the system studies of

Rajasthan power system for development of power transmission system in Rajasthan and

planning of the power evacuation system for new power plants. His research interest

includes Reactive Power Optimization, Power System Stability, reduction of T&D losses and

protection of power system.

Sarfaraz Nawaz has received his B.E. degree from University of

Rajasthan and M.Tech. degree from MNIT, Jaipur. His research interests

include power systems and power electronics. He is currently an Associate

Professor of the Electrical Engg. Dept., Swami Keshvanand Institute of

Technology, Management and Gramothan (SKIT), Jaipur, Rajasthan.