national power system expansion plan

National Transmission and Despatch Company Limited National Transmission and Despatch Company Limited

National Power System Expansion Plan

2011 - 2030

Final ReportAnnexure 3: Transmission PlanAnnexure 3: Transmission Plan

504760-01-A32011

SNC-Lavalin International Inc

Prepared by

SNC Lavalin International Inc.in association with

National Engineering Services Pakistan (PVT) Limited

504760 © 2011 SNC-Lavalin Inc. All rights reserved T&D Division Confidential

NOTICE This document contains the expression of the professional opinion of SNC-Lavalin Inc. (“SLI”) as to the matters set out herein, using its professional judgment and reasonable care. It is to be read in the context of the agreement dated October 4, 2010 (the “Agreement”) between SLI and National Transmission and Despatch Company (the “Client”), and the methodology, procedures and techniques used, SLI’s assumptions, and the circumstances and constraints under which its mandate was performed. This document is written solely for the purpose stated in the Agreement, and for the sole and exclusive benefit of the Client, whose remedies are limited to those set out in the Agreement. This document is meant to be read as a whole, and sections or parts thereof should thus not be read or relied upon out of context. Unless expressly stated otherwise, assumptions, data and information supplied by, or gathered from other sources (including the Client, other consultants, testing laboratories and equipment suppliers, etc.) upon which SLI’s opinion as set out herein is based has not been verified by SLI; SLI makes no representation as to its accuracy and disclaims all liability with respect thereto.

National Power Systems Expansion Plan

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LIST OF ABBREVIATIONS AND DEFINITIONS Abbreviations: ADB Asian Development Bank

AEDB Alternative Energy Development Board

cct-km Circuit-kilometre

Consultant SNC-Lavalin, Transmission and Distribution Group

DISCO Distribution Company

DSM Demand Side Management

GDP Gross Domestic Product

GENCO Generation Company

HPP Hydel (or Hydro) Power Project

HSFO High-Sulphur Furnace Oil

HVAC High Voltage Alternating Current

HVDC High Voltage Direct Current

IEEE Institute of Electrical and Electronic Engineers

kA Kilo-ampere

KESC Karachi Electric Supply Company

km Kilometre

KPT Karachi Port Trust

kV Kilovolt

MMcfd Million cubic feet per day

MOU Memorandum of Understanding

MT Metric Tonnes

MTOE Million Tons of Oil Equivalent

MVA Mega volt-amperes

MWh Megawatt-hour or 1,000 kilowatt-hours

NEPRA National Electric Power Regulatory Authority

NESPAK National Engineering Services Pakistan (Pvt) Limited

NPP National Power Plan, prepared by Acres International Limited in 1994

NTDC National Transmission and Despatch Company

OGDCL Oil and Gas Development Company Limited

P.P. Power Project

PAEC Pakistan Atomic Energy Commission

PARCO Pak-Arab Refining Company

PEPCO Pakistan Electric Power Company

National Power Systems Expansion Plan

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PPIB Private Power and Infrastructure Board

PPL Pakistan Petroleum Limited

PQA Port Qasim Authority

PSO Pakistan State Oil

PSS/E Power System Simulation

RFO Residual Furnace Oil

SIL Surge Impedance Load

SNGPL Sui Northern Gas Pipeline Limited

SSGCL Sui Southern Gas Company Limited

SYPCO Generation planning software (System Production Costing)

TAVANIR The Iranian Electric Utility

WAPDA Water and Power Development Authority


504760-01-A3 i Transmission Plan

TABLE OF CONTENTS

NTDC TRANSMISSION EXPANSION PLAN

1 OBJECTIVES .................................................................................................................. 1 2 PLANNING AND PERFORMANCE CRITERIA .............................................................. 1 3 TYPICAL CHARACTERISTICS OF NTDC LONGITUDINAL NETWORK ...................... 3 4 APPROACH AND METHODOLOGY .............................................................................. 5

4.1 Inputs ........................................................................................................................ 5

4.2 Development of Study Cases ................................................................................... 5

5 DETERMINATION OF FUTURE NEEDS OF 500/220 KV & 220/132 KV GRID STATIONS ....................................................................................................................... 7

5.1 Load Forecast ........................................................................................................... 7

5.2 Needs of 500/220 kV and 220/132 kV Grid Stations till 2020/21 .............................. 7

5.3 Needs of 500/220 kV and 220/132 kV Grid Stations from 2020/21 to 2029/30 ........ 8

6 TRANSMISSION EXPANSION UP TO 2016-17 ............................................................. 9 6.1 Expansion Scheme ................................................................................................... 9

6.2 Power Dispersal Projects: Till 2016-17 ..................................................................... 9

6.3 Power Import Projects: Till 2016-17 ...................................................................... 11

6.4 New Grid Stations of 500/220 kV at Load Centers: Till 2016-17 ............................ 11

6.5 New Grid Stations of 220/132 kV at Load Centers: Till 2016-17 ............................ 12

6.6 Load Flow Results of the year 2016-17 .................................................................. 14

7 TRANSMISSION EXPANSION FROM 2016-17 TO 2020-21 ....................................... 16 7.1 Expansion Scheme ................................................................................................. 16

7.1.1 Power Dispersal Projects: 2016-17 to 2020-21 .................................................. 17

7.1.2 New 500/220 kV Grid Stations at Load Centers: 2016-17 to 2020-21 ................ 20

7.1.3 New 220/132 kV Grid Stations at Load Centers: 2016-17 to 2020-21 ................ 21

7.1.4 New Transmission Lines for System Reinforcements Required for Normal and N-1 Contingency Conditions: 2016-17 to -2020-21 ................................................. 22

7.1.5 Augmentations and Extensions at 500/220 kV and 220/132 kV Grid Stations: 2016-17 to -2020-21 ............................................................................................ 22




8.1.2 New 500/220 kV Grid Stations and Related Transmission Lines of 500 kV: 2021-22 to 2025-26 ...................................................................................................... 29


504760-01-A3 ii Transmission Plan

8.1.3 New 220/132 kV Grid Stations and Related Transmission Lines of 220 kV: 2021-22 to 2025-26 ...................................................................................................... 30

8.1.4 New Transmission Lines for System Reinforcements Required for Normal and N-1 Contingency Conditions: 2021-22 to 2025-26 .................................................. 32

8.1.5 Augmentations and Extensions at 500/220 kV and 220/132 kV Grid ................. 33




9.1.2 New 500/220 kV Grid Stations and Related Transmission Lines of 500 kV: 2026-27 to 2030 ........................................................................................................... 40

9.1.3 New 220/132 kV Grid Stations and Related Transmission Lines of 500 kV: 2026-27 to 2030 .................................................................................................. 40

9.1.4 New Transmission Lines for System Reinforcements Required for Normal and N-1 Contingency Conditions: 2026-27 to 2030 ....................................................... 41

9.1.5 Augmentations and Extensions at 500/220 kV and 220/132 kV Grid 2026-27 to 2030 .................................................................................................................... 41

9.2 Load Flow Results of the year 2030 ....................................................................... 42

10 SHORT CIRCUIT ANALYSIS ........................................................................................ 49 10.1 Significance of Short Circuit Analysis ..................................................................... 49

10.2 Methodology and Assumptions for Maximum Fault Current Calculations .............. 49

10.3 Fault Current Calculations of the year 2020 ........................................................... 51

10.4 Fault Current Calculations of the year 2030 ........................................................... 52

11 TRANSIENT STABILITY STUDIES .............................................................................. 55 11.1 Stability Studies for the year 2020 .......................................................................... 56

11.2 Stability Studies for the year 2030 .......................................................................... 58

11.3 General Conclusions of Stability Studies ................................................................ 61

12 COST ESTIMATE OF TRANSMISSION EXPANSION ................................................. 61 12.1 Total requirement (BOQs) between 2017 and 2030 ............................................... 61

12.2 Total Cost ............................................................................................................... 62

13 CONCLUSIONS & RECOMMENDATIONS .................................................................. 62


504760-01-A3 iii Transmission Plan

LIST OF FIGURES

Figure 3-1 Existing/Committed 500/220 kV System ........................................................... 4

Figure 9-1 500/220 kV System in the Ultimate Year 2030 ................................................ 48

LIST OF APPENDICES

Appendix-1: Input Data

Appendix-2: Load Flow Study Results for year 2016-17



Appendix-5: Load Flow Study Results for year 2030

Appendix-6: Short Circuit Study Results for year 2020

Appendix-7: Short Circuit Study Results for year 2030

Appendix-8: Stability Study Results for year 2020

Appendix-9: Stability Study Results for year 2030

Appendix-10: Transmission Expansion Schedule


504760-01-A3 1 Transmission Plan

NTDC TRANSMISSION EXPANSION PLAN

1 OBJECTIVES

The transmission expansion plan for NTDC has been developed to fulfil the following

objectives:

• To ensure that the planned generation expansion can be delivered to the major load

centres throughout the country

• To identify any requirements (technical and/or economic) that might require the

introduction of any new voltage levels and/or transmission types into the existing

transmission network

• To determine the reinforcements required in the transmission network to meet the

growing demand of the load centres by developing new grid stations and their

associated transmission lines at 500 kV and 220 kV levels interconnecting with the

transmission lines emanating from the proposed power plants.

• To fulfill the reliability criteria of NTDC Grid Code approved by NEPRA in terms of

acceptable voltage, frequency, loading of lines and transformers for normal (N-0) and

contingency (N-1) conditions both under disturbed dynamic/transient conditions and

steady state conditions.

• To determine the long-term impacts on fault levels throughout the transmission

network and to examine mitigating measures to deal with excessive fault levels.

• To check the transient and dynamic stability of 500 kV HVAC or above, and HVDC

systems catering for the bulk transmission of power from major power plants to the

major load centres to verify the adequacy of network for normal and disturbed

conditions.

• To estimate the economic cost of these reinforcements in a staged manner. Such

costs are then added to the cost of the new generation required to provide the basic

input data to the financial analysis and the examination of the impact on tariffs.

2 PLANNING AND PERFORMANCE CRITERIA

The transmission system expansion plans are required to fulfil the Grid Code of NTDC

approved by NEPRA, the regulatory authority of electrical power in Pakistan. The following

are the planning and performance criteria laid down in the Grid Code:



Steady State:

Adequacy evaluation of planning studies for steady-state system performance shall be

based on equipment loading, congestion management, fault levels and voltage regulation.

Steady-state planning studies for steady state load flow studies shall be deemed acceptable

if they do not result in any voltage violations or overloads based on predetermined loading

limits for Normal (N-0) and Emergency (N-1) contingency conditions.

Dynamic/Transient Conditions:

System stability must be maintained following the disturbances listed below:

(a) Permanent three-phase faults on any primary transmission line and associated

components. It is assumed that a fault will be cleared by circuit breaker action in 5 cycles.

(b) Failure of a circuit breaker to clear a fault (“Stuck Breaker” condition) in 5 cycles, with

back up clearing in 9 cycles after fault initiation

The robustness of the proposed transmission expansion plan shall be tested against

criterion (a) whereas the worst case of critical clearing time i.e. criterion (b) needs to be

applied at detailed design stage of generating stations. If the System is found to be unstable,

then mitigation measures shall be identified and incorporated into the system improvement

plans for future years.

Grid Frequency Variations:

The Frequency of the NTDC Transmission System shall be nominally 50Hz and shall be

maintained within the limits of 49.8 to 50.2 unless exceptional circumstances prevail.

Grid Voltage Variations:

Under (N-0) normal operating conditions, System Operating Voltages of the Total System

shall be maintained within the bandwidth of +8% to –5% of Nominal System Voltage. Under

(N-1) contingency operating conditions, the voltage variation shall be in the range of +10%

and –10% of Nominal System Voltage

Short Circuit (Fault Levels):

Short circuit calculations shall be prepared for each study year, and adequacy of fault

interrupting capability and short circuit withstand capacity shall be ensured.



3 TYPICAL CHARACTERISTICS OF NTDC LONGITUDINAL NETWORK

Pakistan is geographically a longitudinal country, i.e. more like a vertical rectangle and same

is true for the primary network of NTDC. The 500 kV network runs from Peshawar in the

North to HUBCO near Karachi in the South (see Figure 3.1).

The maximum load is concentrated in the middle of the country where local generation

potential is limited because of lack of fossil fuel resources and meagre hydropower potential

in the plains. Hydropower generation potential is located in the North and thermal power

generation sources are mainly in the South. The least cost Generation Plan (Base Case)

developed for this Expansion Plan Study also envisages maximum hydropower generation

located up in the North whereas the major thermal power plants based on indigenous and

imported fossil fuel are located in South. Therefore during high water months when hydel

power is at the maximum the power flows from the North to South, whereas in low water

months when the thermal power in the South is run at its maximum, the power flow is

reversed to be from the South to North. Long HVAC (500 kV or above) and HVDC lines are

required to carry power from the far North and far South to mid country where the maximum

load is concentrated.

With insignificant local generation in mid-country, the huge reactive power (MVAR) demand

would not be advisable to be supplied from power plants in the far North and far South as

excessive flow of VARs would cause severe voltage drop across long and heavily loaded

lines, therefore sufficient VAR sources would be required to be installed in terms of shunt

capacitor banks at the distribution level and, if required, at the transmission level as well.

Other dynamic VAR compensation devices such as SVCs, SVS, and other FACTS devices

might be required to be installed at appropriate locations in mid-country.

Also in the high water season, when power flows mainly from hydel power plants in the

North, the HVAC circuits in the South would be lightly loaded because of the low dispatch of

thermal power from the South and vice versa. The lightly loaded HVAC lines generate

excessive VARs due to their high charging current and would require a sufficient amount of

shunt reactors, line connected or bus connected depending on the requirement. Therefore

the levels of compensations, inductive and capacitive, are to be very carefully studied and

planned.



Figure 3-1 Existing/Committed 500/220 kV System



4 APPROACH AND METHODOLOGY

4.1 Inputs

The following input data has been assumed for the study cases:

• Load Forecast, base case scenario, prepared by NTDC and validated by SNC-

Lavalin (Appendices1.1 and 1.2)

• Base Case Generation Expansion Plan developed by SNC-Lavalin for NPSEP

(Appendix-1.4)

• Transmission network data file in PSS/E format supplied by NTDC for the years

2010 and 2014

• All the ongoing and committed or planned transmission expansion plans of

NTDC envisaged up to the year 2016-17 (Appendix-1.5).

• Inputs from the other ongoing feasibility studies have been incorporated as

follows:

o ± 500 kV HVDC Bipole for 1000 MW import of power from Iran

(conducted by NESPAK and SNC Lavalin)

o ± 500 kV HVDC Bipole for 1300 MW import of power from CASA

(conducted by NESPAK and SNC Lavalin)

o Transmission scheme based on 500 kV double circuits using quad

bundled Martin conductor for the evacuation of power from 26

hydropower plants to be located on river Indus and its tributaries in

Northern Areas of Pakistan (being conducted by PB/PPI/MAES)

o Transmission scheme for evacuation of power from indigenous and

imported coal based thermal power plants in the South (Thar and

Karachi) connecting with the Southern Grid at 500 kV and at ± 600 kV

HVDC from South to Mid-country (being conducted by NESPAK and

SNC Lavalin)

4.2 Development of Study Cases

• The spot years for study have been identified in agreement with NTDC

corresponding to different intervals in which major generation additions occur as

per the Base Case Generation Expansion Plan, which are 2016, 2020, 2025 and

2030 respectively.



• Base case of the year 2020 was developed as a reference to develop the other

spot years’ cases. DISCO transmission expansion plan up to the 132 kV level

developed till the year 2020 was used as the fundamental base case,

superimposing the NTDC transmission infrastructure of 220 kV and 500 kV

adequate to meet the DISCO transmission needs with the proposed extensions,

augmentations and construction of new 500/220 kV and 220/132 kV substations

• Case for the year 2030 was developed to determine the ultimate scope of 220 kV

and 500 kV transmission additions in the system to meet the projected forecast

and the corresponding generation additions. The expansion of DISCO

transmission network up to the 132 kV level was assumed frozen at the year

2020 and future projections of loads were assumed lumped at new 220/132 kV

substations proposed to be constructed between 2020 and 2030.

• The cases for the intermediate years of 2016 and 2025 were developed to

determine the scope of the transmission system expansion during the

intermediate years.

• Standard tools of analysis for transmission expansion planning i.e. load flow,

short circuit and transient stability analyses were employed using the state of art

software PSS/E® of Siemens-PTI.

• Two cases each for high water (high hydel) and low water (high thermal) were

studied for each spot year of the study i.e. 2016, 2020, 2025 and 2030. Load flow

simulations were carried out for normal (N-0) and ) contingency (N-1) conditions

for each case to determine the adequacy of the proposed transmission facilities

for each seasonal pattern of power flow

• Short circuit analysis was carried out for the calculation of maximum three-phase

and single-phase fault currents for the years 2020 and 2030 using IEC 909 as

employed in PSS/E® software.

• Transient stability analysis was carried out for the system of 500 kV for the years

2020 and 2030 employing the following standard worst case disturbance:

o 3-phase fault at bus bar with fault clearing time of 5 cycles

o Trip of the heavily loaded circuit emanating from the bus bar

o Monitor post fault damping of transients of rotor angles and power swings

with recovery of voltage and frequency of the system



5 DETERMINATION OF FUTURE NEEDS OF 500/220 KV & 220/132 KV GRID STATIONS

5.1 Load Forecast

NTDC has developed two scenarios of load forecast based on:

• Power Market Survey (PMS)

• Long Term Forecast involving growth indices of country globally

These forecasts are attached as Appendices 1.1 and 1.2. The first one may be called

“bottom-up” approach initiating from grass root level of 11 kV feeders and developed up to

132 kV level of DISCO peak. The other approach may be called “top down” that considers

overall country’s growth indices and develops future peak demand globally at country level

and then breaks it down to DISCO peaks.

The PMS forecast was used for developing the DISCO and NTDC transmission expansion

plans up to the year 2020. Individual DISCO peak cases have been combined together to

make a composite case for NTDC transmission expansion of the spot years of study up to

2020.

5.2 Needs of 500/220 kV and 220/132 kV Grid Stations till 2020/21

For NTDC transmission system expansion between 2021 and 2030, the global forecast was

used because the focus is only on 500 kV and 220 kV network expansion in these years;

being given that the132 kV network expansion was frozen as of the year 2020.

Future reinforcements up to 2020 in the existing 220/132 kV grid stations in terms of

augmentation or addition and requirements for new 220/132 kV grid stations have been

worked out based on the following:

• Tentative transmission expansion plan up to 2016-17 supplied by NTDC as attached

in Appendix-1.5

• Need for new 220/132 kV substations established by DISCO transmission expansion

load flow analysis for normal and N-1 contingency cases up to the year 2020.



Expansion of 500/220 kV grid stations up to the year 2020 has also been assumed

principally based on the tentative transmission expansion plan of NTDC (Appendix-1.5) plus

further requirements established due to overloading of 500/220 kV transformers revealed in

load flow analysis of DISCO peaks especially in big load centres of Lahore, Faisalabad,

Islamabad, Peshawar and Karachi.

5.3 Needs of 500/220 kV and 220/132 kV Grid Stations from 2020/21 to 2029/30

Detailed load capacity analysis has been carried out to determine the requirements of new

220/132 kV grid stations to feed different DISCO loads between 2020 and 2030. The results

are attached in Appendix 1.3. The methodology of this analysis is explained below:

• Load flow case of year 2020 for NTDC transmission with all DISCO peak cases

combined in it, has been assumed as the base reference case. All loads

represented at 11kV and 132 kV have been frozen. The power supplied internally

through generation connected at 132 kV and imported from neighbouring DISCOs

(at CDPs) is also frozen

• MW flows on 220/132 kV grid stations feeding each DISCO peak load in 2020 case

have been noted for respective DISCO in separate sheets.

• Sum of MW flows at 220/132 kV transformers and the internal supply at 132 kV

levels is equal to DISCO peak load. The proportion of MW flows through a particular

220/132 kV grid station with reference to total MW flows injected into DISCO peak

as of 2020 base case has been worked out.

• MW flows of 220/132 kV transformers of 2020 base case load flow were projected

up to the year 2030 at the annual growth rates of the respective DISCOs

maintaining the same ratio of MW flow that was worked out from the 2020 base

case load flow.

• The concept of firm capacity i.e. N-1 of the transformers capacity has been applied

for the period 2020 – 2030.

• When the projected MW flows at 220/132 kV grid station cross the firm capacity,

either of the following reinforcements have been proposed

o Augmentation to higher capacity assuming maximum size of transformer to

be 350 MVA



o Addition of transformers depending on availability of space capping

maximum number of transformers to be 4 at one grid station with maximum

size of a transformer as 350 MVA .

o New grid station in the neighbourhood of the same grid station where the

load has exceeded the firm capacity.

• In Appendix 1.3, the results of the load capacity analysis for determining the need of

220/132 kV reinforcements in the concession area of each DISCO has been

presented in separate sheets which indicate replacement (augmentation), addition

(extension) and new 220/132 kV grid stations required between 2020 and 2030.

6 TRANSMISSION EXPANSION UP TO 2016-17

6.1 Expansion Scheme

6.2 Power Dispersal Projects: Till 2016-17

The major generation additions indicated in Generation Expansion Plan (Appendix-1.4),

including the committed and planned power plants, requiring additional transmission

facilities by the year 2016-17 are as follows:

Power Plants Type Installed Capacity, MW

Commissioning Year

Guddu New CC 747 2013-14

Haveli Bahadur Shah CC 3000 2015-16

Sahiwal CC 1414 2015-16

Neelum-Jehlum Hydro 969 2015-16

Thar/Imported Coal Coal 3000 2016-17

CHASHNUPP-III & IV Nuclear 680 2016-18

Import from Iran and CASA Import 2000 2016-17

Wind Power (Gharo/Jhimpir) Wind 1400 2012-17

To meet the forecasted demand and facilitate the evacuation of power from the committed

and planned power plants by the year 2016-17, a corresponding transmission expansion

plan has been developed.

NTDC provided their in-house developed transmission expansion plan till the year 2016-17

as shown in Appendix-1.5. The plan envisages removing the present bottlenecks in the

existing 500 kV and 220 kV network and substations which presently face severe



congestions, overloadings and violations of Grid Code criteria. This plan has been

incorporated as such in the load flow simulations for 2016-17 with some changes proposed

for the evacuation of power from the New Hydropower Plants (PB/PPI/MAES Study) and for

the Thar Coal and Imported Coal based thermal power plants (SNC/NESPAK Study).

The additions of transmission network necessary for the evacuation of power from the major

power plants in NPSEP by 2016-17 would be as follows:

For Guddu–New (CCPP)

o Guddu New CCPP – M. Garh 500 kV S/C

o In-Out of 500 kV Guddu – Multan at Guddu New (CCPP)

o In-out D.G. Khan - Multan 500 kV S/C at M. Garh

For Haveli Bahadur Shah (CCPP)

o Haveli Bahadur Shah CCPP – Faisalabad-West 500 kV D/C

o In-Out of M. Garh – Faisalabad-West S/C at Haveli Bahadur Shah CCPP

o In-Out Gatti – Multan 500 kV S/C at Faisalabad-West

o In-Out Gatti-Rousch 500 kV S/C at Faisalabad-West

For Sahiwal (CCPP)

o In-Out of Sahiwal – Multan 500 kV S/C at Sahiwal (CCPP)

o 500 kV Sahiwal-Lahore- South 500 kV D/C

For Neelum-Jehlum (Hydro)

o Neelum-Jehlum to Gujranwala (Gakhar) 500kV D/C

For Thar (Coal)

o Thar to Matiari switching station 500 kV D/C

For Imported Coal (AES)

o In-Out of Hub-Jamshoro 500 kV S/C at AES

o AES to Matiari 500 kV D/C

o In–out of AES-Matiari 500 kV S/C at Public Sector (Imported Coal)

o In-out of 500 kV Jamshoro-Moro S/C at Matiari

For CHASHNUPP-III and IV (Chashma New)

o Chashma New – Bannu 220 kV D/C

o In-out of 220 kV D.I. Khan – Jauharabad S/C at Chashma New



For two clusters of wind power plants at Gharo and Jhimpir

o Jhimpir – T.M Khan Road 220 kV D/C

o Gharo - Jhimpir 220 kV D/C

6.3 Power Import Projects: Till 2016-17

For import of power from Iran

o ± 500 kV HVDC Bipoles from Zahedan to Quetta

o Quetta - Loralai 220 kV D/C

o Quetta - Quetta Ind. 220 kV D/C o Quetta - Mastung 220 kV D/C

For import of power from CASA

o ± 500 kV HVDC Bipoles from Tajikistan to Peshawar-2

o In-out of Tarbela – Peshawar 500 kV S/C at Peshawar-2 (new 500/220kV substation)

o In-out of Peshawar – Shahibagh 220 kV S/C at Peshawar-2

6.4 New Grid Stations of 500/220 kV at Load Centres: Till 2016-17

The new 500/220 kV grid stations at load centres to be added in the system by 2016-17 with their proposed installed capacities and connectivity schemes are as follows:

No. New 500/220 kV

Grid Station Capacity

MVA Connectivity at 500 kV

1 R. Y. Khan 2x600 Guddu-New – Multan In-Out at R.Y. Khan

2 D. G. Khan 2x600 Guddu – Multan In-Out at D.G. Khan

3 Shikarpur-New 2x600 Guddu – Dadu 1st and 2nd circuits In-Out at Shikarpur New

4 Peshawar-2 2 x 750 In-out of Tarbela – Peshawar 500 kV S/C at Peshawar-2

5 Islamabad-West 2 x 750 Tarbela – Rewat 500 kV S/C In-Out at Islamabad West

Ghazi Brotha – Rewat 500 kV S.C In-Out at Islamabad West

In-Out of Tarbela-ISPR 220 kV at Islamabad West 220 kV

6 Lahore-South 2 x 750 Sahiwal – Lahore S/C In-Out at Lahore South Lahore-South – Lahore D/C

7 Faisalabad- West 2 x 750 M. Garh – Gatti S/C In-Out at Faisalabad-West



The details of extensions and augmentations proposed in the existing 500/220 kV grid

stations are indicated in detail in Appendix-1.5

6.5 New Grid Stations of 220/132 kV at Load Centers: Till 2016-17

The new 220/132 kV grid stations going to be added in the system by 2016-17 with their

proposed installed capacities and connectivity schemes are as follows:

No. New 220/132 kV Grid Station

Capacity MVA Connectivity at 220 kV

1 Rohri New 2x250 Engro IPP – Rohri New 220 kV D/C Rohri New – Shikarpur 220 kV D/C

2 Kassowal 2 x 160 Vehari – Yousafwala 220 kV D/C In-Out at Kassowal

3 Bandala 2 x 160 Gatti – K.S.K 220 kV D/C In-Out at Bandala

4 Khuzdar 2 x 160 Dadu – Khuzdar 220 kV D/C

5 Wapda Town 2 x 250 Lahore–New K.L. Pat 220 kV D/C In-Out at Wapda Town

6 Mansehra 2 x 250 Allai Khwar – Mansehra 220 kV D/C Mansehra – Isbd. Pesh. Road 220 kV D/C

7 Ghazi Road 3 x 160 • K.S. Kaku–Ravi 220 kV S/C In-Out at Ghazi Road

• NKLPT – Sarfraznagar 220 kV S/C In-Out at Ghazi Road

8 Loralai 2 x 250 D.G. Khan – Loralai 220 kV D/C

9 Okara New 3 x 250 Yousafwala – Sarfraznagar D/C In-Out at Okara New

10 Gujrat New 3 x250 Mangla – Gujranwala 220 kV S/C & Mangla – Gakhar 220 kV S/C In-Out at Gujrat

11 T.T. Singh 3 x 250 Multan – Samundri Rd 220 kV D/C In-Out at T.T. Singh

12 Nowshera Ind. 3 x 250 G.Brotha – Shahibagh 220 kV D/C In-Out at Nowshera Ind.

13 R.Y. Khan 500/220/132 kV

2 x 250

14 Chishtian New 2 x 250 Vehari – Chishtian New 220 kV D/C

15 Shalamar 3 x 160 Ravi/K.S.K – Ghazi Raod220 kV D/C In-Out at Shalamar

16 D.M. Jamali 1 x 160 + 1 x 100

Uch – Guddu 220 kV S/C In-Out at D.M. Jamali

17 D.I. Khan 2 x 250 In & Out of Chashma– Ludewala 220 kV S/C at





D.I. Khan

18 Chakwal New 2 x 160 Mangla – Rewat 220 kV S/C In-Out at Chakwal New

19 Lalian New 2 x 250 Gatti – Ludewala 220 kV D/C In-Out at Lalian New.

20 MirpurKhas New 2 x 160 Hala Road – T.M. Khan Road 220 kV D/C Hala Road – T.M.Khan Road 220 kV S/C In-Out at MirpurKhas New.

21 Shadman 2 x 250 Shadman – Bund Road 220 kV D/C (XLPE Cable)

22 Taxila 2 x 250 Tarbela/Burhan – Islamabad Pesh. Road 220 kV D/C In-Out at Taxila

23 Chakdara 2 x 250 Mardan – Chakdara 220 kV D/C

24 Jhimpir 2 x 250 Jhimpir – T.M. Khan Road 220 kV D/C

25 Gharo 2 x 250 Garho – Jhimpir 220 kV D/C

26 D.G. Khan 500/220/132 kV

2 x 250

27 Mastung 2 x 250 Sibbi – Mastung 220 kV D/C

28 Faisalabad West 500/220/132 kV

2 x 250 Samundri Road – Jhang Road 220 kV D/CFaisalabad West – T.T. Singh 220 kV D/C

29 M-3 Industrial Estate

2 x 250 Faisalabad West – M-3 Industrial Estate 220 kV D/C Faisalabad West – M-3 Industrial Estate 220 kV S/C In-Out at Lalian

30 Jamrud 2 x 250 Peshawar – Jamrud 220 kV D/C

31 Kohat 2 x 250 Peshawar New – Kohat 220 kV D/C Bannu – Kohat 220 kV D/C

32 Islamabad I-10 2 x 250 Rewat – Islamabad University 220 kV D/C In-Out at Islamabad I-10

33 Kamalabad 2 x 250 Rewat – Islamabad Pesh. Road 220 kV D/C In-Out at Kamalabad

34 Kamra 2 x 250 Tarbela – Taxila 220 kV S/C In-Out at Kamra

35 Iqbal Town 2 x 250 Lahore – Wapda Town 220 kV D/C In-Out at Iqbal Town

36 Gujranwala New (In-between Theri Sansi & G.P. Road)

2 x 250 Mangla – K.S. Kaku 220 kV S/C In-Out at Gujranwala New Gujranwala – Gujranwala New 220 kV D/C





37 P. Bhattian Ind. 2 x 250 Gujranwala – P. Bhattian Ind. 220 kV D/C

38 Head Faqirian 2 x 250 Ludewala – Head Faqirian 220 kV D/C

39 Jauhrabad 2 x 250 Ludewala – Chashma/D.I.Khan 220 kV D/C In-Out at Jauhrabad

40 Alizai 2 x 250 Kohat – Alizai 220 kV D/C

41 Arifwala 2 x 250 Yousafwala – Kassowal 220 kV D/C In-Out at Arifwala

The additions, augmentations, extensions etc. at 500 kV and 220 kV planned till 2016-17 to

resolve congestion and overloading in the system have been indicated in Appendix-1.5 and

are modeled and indicated in the load flow study results.

6.6 Load Flow Results of the year 2016-17

Load flow studies for high water (low thermal) and low water (high thermal) have been

performed for normal (N-0) and contingency (N-1) conditions for each case. The automatic

contingency analysis (ACCC) facility of PSS/E® was used for the 220 kV network assuming

thermal limit as the permissible loading limit because 220 kV lines in the NTDC network are

not very long. However for the 500 kV system separate load flow simulations were

performed for each individual outage of a 500 kV circuit. The loading limit in 500 kV may

not be the thermal limit and it is necessary to see the loading levels on the intact circuits for

each individual outage case from the point of view of stability limits.

The drawings of plotted results for high (HW) and low water (LW) cases are placed in

Appendices 2.1 and 2.2 respectively.

Normal (N-0) cases:

Exhibit-2016-HW-1.0 Results of Northern System of 500 kV

Exhibit-2016-HW-2.0 Results of Southern System of 500 kV and 220 kV


Exhibit-2017-LW-1.0 Results of Southern System of 500 kV and 220 kV

Exhibit-2017-LW-2.0 Results of Northern System of 500 kV




The results indicate that in the high water season, the 500 kV circuits in the Northern system

i.e. North of Multan and Sahiwal, are relatively heavily loaded compared to those in the

Southern system and vice versa in the low water season. This is for the obvious reasons of

dispatch of more power from hydropower plants located in North and less power from

thermal power plants in the South during HW season and vice versa in LW season. Voltages

on the 500 kV and 220 kV systems on the entire NTDC system from North to South are

within the normal permissible limits of the NEPRA Grid Code. The power flows on the lines

of 500 kV and 220 kV and 500/220kV and 220/132 kV transformers are also within their

rated limits.

Contingency (N-1) cases:

The automatic contingency analysis (ACCC) for 220 kV network indicates no violations of

voltage and line loadings establishing the adequacy of 220 kV lines and 220/132 kV

transformers envisaged in the NTDC proposed tentative expansion plan up to 2016-17.

The one-line-out contingency cases of the 500 kV system has been carried out for Northern

system for HW season and for Southern system for LW season respectively.

The plotted results are placed in Appendices 2.1 and 2.2 as follows:

Outages for HW season (Appendix 2.1):

Exhibit-2016-HW-1.1 Peshwar-2 to Tarbela 500 kV Single Circuit Out

Exhibit-2016-HW-1.2 Tarbela to G.Brotha 500 kV Single Circuit Out

Exhibit-2016-HW-1.3 Tarbela to ISBD-W 500 kV Single Circuit Out

Exhibit-2016-HW-1.4 ISBD-W to G.Brotha 500 kV Single Circuit Out

Exhibit-2016-HW-1.5 G.Brotha to Gatti 500 kV Single Circuit Out

Exhibit-2016-HW-1.6 Gatti to FBD-W 500 kV Single Circuit Out

Exhibit-2016-HW-1.7 FBD-W to Haveli-P 500 kV Single Circuit Out

Exhibit-2016-HW-1.8 ISBD-W to Rewat-N 500 kV Single Circuit Out

Exhibit-2016-HW-1.9 Rewat-N to G.Brotha 500 kV Single Circuit Out

Exhibit-2016-HW-1.10 Rewat-N to Gujranwala 500 kV Single Circuit Out

Exhibit-2016-HW-1.11 N-Jehlum to Gujranwala 500 kV Single Circuit Out

Exhibit-2016-HW-1.12 Gujranwala to Lahore-O 500 kV Single Circuit Out

Exhibit-2016-HW-1.13 Lahore-O to Gatti 500 kV Single Circuit Out



Outages for LW season (Appendix 2.2):

Exhibit-2017-LW-1.1 Tharcoal to Matiari 500 kV Single Circuit Out

Exhibit-2017-LW-1.2 Matiari to Jamshoro 500 kV Single Circuit Out

Exhibit-2017-LW-1.3 AES-Coal to NKI 500 kV Single Circuit Out

Exhibit-2017-LW-1.4 HUB to NKI 500 kV Single Circuit Out

Exhibit-2017-LW-1.5 Matiari to Moro 500 kV Single Circuit Out

Exhibit-2017-LW-1.6 Jamshoro to Dadu 500 kV Single Circuit Out

Exhibit-2017-LW-1.7 Dadu to Shikarpur 500 kV Single Circuit Out

Exhibit-2017-LW-1.8 Shikarpur to Guddu 500 kV Single Circuit Out

Exhibit-2017-LW-1.9 Moro to R.Y.Khan 500 kV Single Circuit Out

Exhibit-2017-LW-1.10 D.G.Khan to M.Garh 500 kV Single Circuit Out

Exhibit-2017-LW-1.11 Guddu to Guddu-New 500 kV Single Circuit Out

Exhibit-2017-LW-1.12 Guddu to M.Garh 500 kV Single Circuit Out

Exhibit-2017-LW-1.13 R.Y.Khan to Multan 500 kV Single Circuit Out

Exhibit-2017-LW-1.14 M.Garh to Multan 500 kV Single Circuit Out

Exhibit-2017-LW-1.15 M.Garh to Haveli-P 500 kV Single Circuit Out

Exhibit-2017-LW-1.16 Multan to FBD-W 500 kV Single Circuit Out

Exhibit-2017-LW-1.17 Multan to Rousch 500 kV Single Circuit Out

Exhibit-2017-LW-1.18 Rousch to FBD-W 500 kV Single Circuit Out

Exhibit-2017-LW-1.19 Multan to Sahiwal 500 kV Single Circuit Out

The results indicate that power flows on the intact circuits of 500 kV and 500/220 kV

transformers for each outage are within the limits. The voltage profile on all 500 kV bus bars

is also within the permissible criteria.

The above analysis establishes the fact that the proposed expansion scheme of the 500 kV

and 220 kV network till 2016-17 is adequate and fulfills the criteria of the Grid Code.

7 TRANSMISSION EXPANSION FROM 2016-17 TO 2020-21


The sizes of 500/220 kV transformer banks are to be multiples of 750 MVA or 1000 MVA for

all the new 500/220 kV grid stations and multiples of 250 MVA or 350 MVA for all the new

220/132 kV substations as per requirements.



The consolidated list of all the transmission expansion projects between 2016-27 and 2020-

21 is provided in Appendix-10.1.

7.1.1 Power Dispersal Projects: 2016-17 to 2020-21

Following are the major additions of power plants between 2016-17 and 2020-21 proposed

in the NPSEP:

New Power Plants Type Installed Capacity, MW

Commissioning Year

Thar Coal 2400 2017-18

Tarbela 4th Extension Hydro 960 2017-18

Karot Hydro 720 2017-18

Asrit-Keddam Hydro 215 2017-18

Madyan Hydro 157 2017-18

Golan Goal Hydro 106 2017-18

Thar Coal 4200 2018-19

Azad Pattan Hydro 222 2018-19

Chakothi Hydro 500 2018-19

Kalam-Asrit Hydro 197 2018-19

Gabral-Kalam Hydro 101 2018-19

Shogosin Hydro 127 2018-19

Shushgai Hydro 102 2018-19

Thar Coal 4200 2019-20

Chashma Nuclear 1000 2019-20

Suki Kinari Hydro 840 2019-20

Kaigah Hydro 548 2019-20

Thar Coal 2400 2020-21

Diamer Basha 1 Hydro 2250 2020-21

Bunji 1 Hydro 1800 2020-21

Qadirabad Nuclear 1000 2020-21

Wind Power (Total) Wind 400 2017-2021

All rental power plants such as Samundri, Gulf, Walters, Karkey and Reshma have been

assumed dismantled and not considered in the study for this period.



The already proposed interconnection schemes by NTDC for Neelum Jhelum and Karot

hydro power plants have been modified to call at new hydropower plants on its way.

The transmission additions vital for the evacuation of power from these major power plants

in the NPSEP between 2016-17 and 2020-21 would be as follows:

For Thar Coal

o ± 600 kV HVDC 2x2000 MW Bipoles from Thar to Lahore-South with

converter stations of same capacity on both ends

o ± 600 kV HVDC 2x2000 MW Bipoles from Thar to Faisalabad-West with


o 500 kV D/C from Thar to Karachi (a new 500/220 kV substation at KDA-33)

For Karot

o In-out of one circuit of 500 kV D/C Neelum Jehlum to Gujranwala

For Azad Pattan

o In-out of one circuit of 500 kV D/C Neelum Jehlum to Gujranwala

o In-out Neelum Jehlum - Gujranwala 500 kV D/C at Aliot Switching Station is

required for interconnection of Both Karot and Azad Pattan HPPs

For Diamer-Basha 1 and Bunji 1

o Basha - Chilas 500 kV D/C

o Basha - Mardan New 500 kV D/C via Swat Valley

o Bunji - Chilas 500 kV D/C

o Chilas - Aliot 500 kV D/C

o Two 500 kV Switching Stations of Chilas & Aliot and a 500/220/132 kV

substation of Mardan New to feed local loads

o Aliot - Islamabad West 500 kV D/C

o Aliot - Lahore-North 500 kV D/C (new 500/220 kV substation of Lahore-North)

For Gabral-Kalam, Kalam-Asrit, Asrit-Kedam, and Madyan (Swat Valley HPPs)

o In-out one each of Basha-Mardan 500 kV D/C at each of Swat HPPs

For Shogosin, Shushgai and Golen Gol (Chitral Valley HPPs)

o Chitral 220/132 kV substation to collect power from all HPPs at 132 kV

o Chitral-Chakdara 220 kV D/C



For Suki Kinari

o In-out of one circuit of 500 kV D/C Chilas-Aliot

For Chakothi

o Chakothi-Aliot 220 kV D/C

o 500/220kV transformers 2x600 MVA at Alliot

For Chashma Nuclear

o Chashma-Ludewala 500 kV D/C

For Kaigah

o Kaigah-Mardan New 500 kV D/C (operated as an interim arrangement until

the commissioning of 2nd stage of Basha).

(This plant would be advisable to be built in the timeline of 2n d stage of Basha.

In that case, its interconnection would be In-out of Basha-Mardan 500 kV S/C

at Kaigah)

For Qadirabad Nuclear

o 500 kV D/C from Qadirabad Nuclear power plant to Gujranwala

The following switching stations will be constructed as power collecting hubs from HPPS on

the rivers Indus, Jehlum and their tributaries:

Chilas 500 kV with following connections:

o Chilas - Basha 500 kV D/C(already mentioned above)

o Chilas - Bunji 500 kV D/C(already mentioned above)

Aliot 500/220 kV with following connections:

o Chilas Aliot 500 kV D/C(already mentioned above)

o In-Out Neelum Jehlum to Gujranwala D/C at Aliot (already mentioned above)

o Aliot - Islamabad-West 500 kV D/C (already mentioned above)

o Aliot - Lahore-North 500 kV D/C with one circuit calling at Gujrat

o Chakothi - Aliot 220 kV D/C (already mentioned above)



7.1.2 New 500/220 kV Grid Stations at Load Centers: 2016-17 to 2020-21

The expansion of the 500 kV network in and around major load centers, such as Peshawar,

Islamabad, Lahore, Faisalabad and Karachi, has been proposed in such a manner that a

ring of 500 kV encircles them with stage by stage additions of new 500/220 kV substations

as needed in future years briefly described below:

• Mardan 500/220 kV, 3x750 MVA, connected as follows:

o With HPPs of Northern Areas through a 500 kV D/C via Swat valley as

discussed above

o With Peshawar-2 through 500 kV D/C

• Matiari 500/220 kV (initially switching station) to be a full substation of 2x750 MVA

capacity

• Islamabad-West 500/220/132 kV (already constructed as discussed above) to

connect to Aliot S/S with 500 kV D/C

• Lahore-South 500/220 kV (already constructed as discussed above), to be built as

big power-hub of HVDC and HVAC connecting:

o With the coal based power plants in South through HVDC Bipoles and

respective converter stations as discussed above and

o With 500 kV ring around Lahore by initially constructing 500 kV D/C Lahore-

South - Lahore-Old. This is in addition to in-out of Lahore-Sahiwal 500 kV S/C

at Lahore-South proposed in 2016-17.

o 500 kV D/C from Lahore-South to Sahiwal (already mentioned above)

• Lahore-North 500/220 kV, 2X1000 MVA to be connected completing the 500 kV ring

around Lahore as follows:

o Gujranwala-Lahore North 500 kV D/C

o Lahore-South to Lahore –North 500 kV D/C

• Faisalabad-West 500/220/132 kV, 2x750 MVA(already constructed as discussed

above), to be built as big power-hub of HVDC and HVAC connecting with the coal

based power plants in South through HVDC Bipoles and respective converter

stations as discussed above

• Following will be carried out at Ghazi-Brotha to avoid overloading in N-1

contingencies at 500 kV circuits between Tarbela and Faisalabad:



o Disconnect one 500 kV circuit each presently connected to Tarbela and Gatti

and jumpers to be connected to bypass Ghazi-Brotha to achieve a direct

Tarbela-Gatti S/C.

o Construct 500 kV D/C from Faisalabad-W to Ghazi Brotha and utilize the two

circuit breakers of 500 kV spared at Ghazi-Brotha, as discussed above, to

connect to Ghazi-Brotha.

• Karachi (near KDA-33) 500/220 kV, 3x1000 MVA, connecting with NKI through

500kV D/C to form a ring of 500 kV around Karachi. Whereas NKI has already been

connected to two Imported Coal fired plants (AES and Public Sector) to form a bigger

ring of 500 kV between Karachi, Jamshoro and Matiari

• Ludewala 500/220 kV, 2x750 MVA (assumed at the same place as of existing

Ludewala 220/132 kV substation having enough space available). It will be

connected to main grid through in-out of Ghazi-Brotha – Gatti 500 kV S/C and

Tarbela-Gatti 500kV S/C (amended as discussed above).

• Gujrat 500/220 kV, 2x750 MVA connected through In-Out Aliot to Lahore-North

500kV S/C

• Vehari 500/220 kV, 2x750 MVA connected through In-Out Multan-Sahiwal 500 kV

S/C

• Moro 500/220 kV, 2x750 MVA (switching station already constructed in 2016-17).

7.1.3 New 220/132 kV Grid Stations at Load Centers: 2016-17 to 2020-21

The detailed transmission expansion studies of all DISCOs for this period have established

the need for new 220/132 kV grid stations. The new 220/132 kV grid stations to be added in

this period are as follows:

Year Substation Voltage Size MVA 220 kV D/C Connections

2018 Shaikh Manda (Quetta) 220/132 2x250 Quetta-New(HVDC) to Sh. Manda

2020 Qasimpur 220/132 3x250 Multan-New to Qasimpur 220 kV (UGC cable if ROW not available)

2020 New Larkana 220/132 2x250 Shikarpur to Larkana-New 220 kV

2020 New Hala 220/132 2x250 Matiari-New-Hala 220 kV

2020 Bhakkar 220/132 2x250 D.I. Khan to Bhakkar 220 kV



7.1.4 New Transmission Lines for System Reinforcements Required for Normal and N-1 Contingency Conditions: 2016-17 to -2020-21

The following additional circuits are required to be added to avoid overloading on lines

during normal and N-1 contingency conditions:

Year Line kV Type

2016 In-Out Karachi-Coal PPs to Matiari at NKI 500kV 2 X D/C

2018 ISBD-West to IBD-P.Rd 220 kV D/C

2018 Mardan-Mardan –New (500/220 kV) 220 kV 2xD/C

2018 Faiselabad-West to Samundri Rd. 220 kV D/C

7.1.5 Augmentations and Extensions at 500/220 kV and 220/132 kV Grid Stations: 2016-17 to -2020-21

Augmentations/Extensions at 500/220 kV grid stations proposed in this period are as follows:

Year Substation Voltage Size Type

2018 Lahore-South 500/220 1x750 MVA Extension

2019 Islamabad-West 500/220 1x750 MVA Extension

2019 Gujranwala (Gakhar) 500/220 1x750 MVA Extension

2019 Rewat 500/220 2x750 MVA Augmentation

2019 Sahiwal (Yousafwala) 500/220 2x750 MVA Augmentation

2020 Peshawar-2 500/220 1x750 MVA Extension

2020 NKI 500/220 2x600 MVA Extension

Twenty three (23) Augmentations/Extensions at 220/132 kV grid stations have been carried

out as explained in Appendix-10.1.


The above transmission scheme is the outcome of load capacity analysis and detailed load

flow analysis. The load flow studies for high hydel (low thermal) and low water (high thermal)

have been performed for normal (N-0) and contingency (N-1) conditions for the study spot

year of 2020-21 for each case. The study results with connectivity of all the new 500kV and



220 kV grid stations and new transmission lines proposed for this period have been plotted

and attached for HW and LW seasons in Appendix-3.1 and 3.2 respectively:

Normal (N-0) cases: Load flow results of normal cases i.e. with no circuits out of service, are attached as follows:


Exhibit-2020-HW-2.0 Results of Southern System of 500 kV and 220 kV


Exhibit-2021-LW-1.0 Results of Southern System of 500 kV and 220 kV



The results indicate the same pattern of power flows as in the previous spot years of study

i.e. heavier flows in Northern circuits of 500 kV and 220 kV during HW season and relatively

lighter flows on Southern grid; and vice versa during LW season. With the proposed

schemes of transmission expansion the system performance fulfills the Grid Code criteria.

The voltages on 500 kV and 220 kV on the entire NTDC system from North to South are

within the normal permissible limits. The power flows on the lines of 500 kV and 220 kV and

500/220kV and 220/132 kV transformers are also within their rated limits.


The automatic contingency analysis (ACCC) for the 220 kV network was carried out which

indicated some violations requiring reinforcement of the network as described above in

section 7.1.4. With the proposed reinforcements the violations of voltage and line loadings

were eliminated.

The one-line-out contingency cases of the 500 kV system have been carried out for Northern

system for HW season; and for Southern system for LW season respectively.



Exhibit-2020-HW-1.1 Basha-1 to Gabral-K 500 kV Single Circuit Out

Exhibit-2020-HW-1.2 Gabral-K to Asrit-K 500 kV Single Circuit Out

Exhibit-2020-HW-1.3 Asrit-K to Madyan -N 500 kV Single Circuit Out

Exhibit-2020-HW-1.4 Basha-1 to K-Asrit 500 kV Single Circuit Out

Exhibit-2020-HW-1.5 Asrit-K to Mardan-New 500 kV Single Circuit Out



Exhibit-2020-HW-1.6 Madyan to Mardan-New 500 kV Single Circuit Out

Exhibit-2020-HW-1.7 Mardan-New to Peshawar 500 kV Single Circuit Out

Exhibit-2020-HW-1.8 Basha-2 to Chilas 500 kV Single Circuit Out

Exhibit-2020-HW-1.9 Bunji to Chilas 500 kV Single Circuit Out

Exhibit-2020-HW-1.10 Chilas to Suki-Knri 500 kV Single Circuit Out

Exhibit-2020-HW-1.11 Suk-Knri to Aliot-S/S 500 kV Single Circuit Out

Exhibit-2020-HW-1.12 Chilas to Aliot-S/S 500 kV Single Circuit Out

Exhibit-2020-HW-1.13 N-Jehlum to Aliot-s/s 500 kV Single Circuit Out

Exhibit-2020-HW-1.14 Tarbela to G-Brotha 500 kV Single Circuit Out

Exhibit-2020-HW-1.15 Tarbela to Ludewala 500 kV Single Circuit Out

Exhibit-2020-HW-1.16 G.Brotha to Ludewala 500 kV Single Circuit Out

Exhibit-2020-HW-1.17 Chashma-Nuc to Ludewala 500 kV Single Circuit Out

Exhibit-2020-HW-1.18 Ludewala to Gatti 500 kV Single Circuit Out

Exhibit-2020-HW-1.19 G.Brotha to FBD-W 500 kV Single Circuit Out

Exhibit-2020-HW-1.20 FBD-W to Multan 500 kV Single Circuit Out

Exhibit-2020-HW-1.21 Haveli to M.Garh 500 kV Single Circuit Out

Exhibit-2020-HW-1.22 Aliot-S/S to ISBD-W 500 kV Single Circuit Out

Exhibit-2020-HW-1.23 ISBD-W to Rewat-N 500 kV Single Circuit Out


Exhibit-2020-HW-1.25 G.Brotha to Rewat-N 500 kV Single Circuit Out

Exhibit-2020-HW-1.26 Aliot-S/S to Karot 500 kV Single Circuit Out

Exhibit-2020-HW-1.27 Karot to Gujranwala 500 kV Single Circuit Out

Exhibit-2020-HW-1.28 Aliot-S/S to Azad Patan 500 kV Single Circuit Out

Exhibit-2020-HW-1.29 Azad Patan to Gujranwala 500 kV Single Circuit Out

Exhibit-2020-HW-1.30 Aliot-S/S to Lahore-N 500 kV Single Circuit Out

Exhibit-2020-HW-1.31 Aliot-S/S to Gujrat 500 kV Single Circuit Out

Exhibit-2020-HW-1.32 Gujrat to Lahore-N 500 kV Single Circuit Out

Exhibit-2020-HW-1.33 Gujranwala to Lahore-N 500 kV Single Circuit Out


Exhibit-2020-HW-1.35 Lahore-N to Lahore-S 500 kV Single Circuit Out

Exhibit-2020-HW-1.36 Lahore-S to Sahiwal 500 kV Single Circuit Out

Exhibit-2020-HW-1.37 Tajikistan to Peshwar-2 500 kV HVDC Monopole Out




Exhibit-2021-LW-1.1 Tharcoal to Matiari 500 kV Single Circuit Out

Exhibit-2021-LW-1.2 Tharcoal to KDA 500 kV Single Circuit Out

Exhibit-2021-LW-1.3 KDA to NKI 500 kV Single Circuit Out

Exhibit-2021-LW-1.4 IMP. Coal to NKI 500 kV Single Circuit Out

Exhibit-2021-LW-1.5 AES Coal to NKI 500 kV Single Circuit Out





Exhibit-2021-LW-1.10 Dadu to Shikarpur 500 kV Single Circuit Out

Exhibit-2021-LW-1.11 Moro to R.Y.Khan 500 kV Single Circuit Out

Exhibit-2021-LW-1.12 Guddu to M.Garh 500 kV Single Circuit Out

Exhibit-2021-LW-1.13 Guddu to D.G.Khan 500 kV Single Circuit Out

Exhibit-2021-LW-1.14 Guddu-New to R.Y.Khan 500 kV Single Circuit Out

Exhibit-2021-LW-1.15 Guddu-New to M.Garh 500 kV Single Circuit Out

Exhibit-2021-LW-1.16 R.Y.Khan to Multan 500 kV Single Circuit Out

Exhibit-2021-LW-1.17 M.Garh to Multan 500 kV Single Circuit Out

Exhibit-2021-LW-1.18 Multan to Vehari 500 kV Single Circuit Out

Exhibit-2021-LW-1.19 Vehari to Sahiwal 500 kV Single Circuit Out

Exhibit-2021-LW-1.20 Haveli to FBD-W 500 kV Single Circuit Out

Exhibit-2021-LW-1.21 Tharcoal to Lahore-S 600 kV HVDC Monopole Out

Exhibit-2021-LW-1.22 Tharcoal-2 to FBD-W 600 kV HVDC Monopole Out

The N-1 contingency load flow results of 500 kV indicate that with the proposed scheme of

500 kV expansion during 2016-17 and 2020-21, all the criteria of Grid Code are met. The

power flows on the intact circuits of 500 kV and 500/220 kV transformers for each outage are

within the limits. The voltage profile on all 500 kV bus bars is also within the permissible

criteria.

The above analysis establishes the fact that the proposed expansion scheme of the 500 kV

and 220 kV network till 2020-21 is adequate and fulfills the criteria of the Grid Code under

normal and N-1 contingency conditions.






For the period from 2021-22 to 2025-26, the major generation additions comprise major

blocks of thermal power at Thar coal fields and hydel power plants in the Northern Areas

across the Indus and its tributaries. The major plants are as follows:

New Power Plants Type Installed Capacity, MW

Commissioning Year

Bhikki CC 1414 2021-22

Thar Coal 600 2021-22

Bunji 2 Hydro 1800 2021-22

Kohala Hydro 1100 2021-22

Munda Hydro 735 2022-23

Bunji 3 Hydro 1800 2022-23

Diamer Basha 2 Hydro 2250 2022-23

Palas Valley Hydro 580 2022-23

Thar Coal 2400 2023-24

Dasu Hydro 4320 2023-24

Lower Spatgah Hydro 496 2023-24

PAEC (Karachi) Nuclear 1000 2023-24

Thakot Hydro 2800 2024-25

Pattan Hydro 2800 2024-25

PAEC (Karachi) Nuclear 1000 2024-25

Thar Coal 3600 2025-26

Dhudnial Hydro 792 2025-26

Wind Power(Total) Wind 2000 2022-26

Some old power plants have been considered retired between the period 2019 and 2025 as

proposed in the Generation Expansion Plan as follows:



Year Retiring Power Plant #of Units

Unit Capacity

MW Total MW

2019 Guddu 285 Faisalabad 129 KESC Gul Ahmed 9 13.5 122 KESC Tapal 12 11.5 138 2020 Jamshoro-ST 1 170 170 Jamshoro 3 164 492 KESC Kannup 114 2021 Shadara 3 9 27 Kotri 2 9 18 Faisalabad 4 18 72 Quetta 25 Kotri 120 Multan 2 28 55 Faisalabad 2 46 92 Guddu 2 58 116 Guddu 2 147 294 2023 Guddu 2 215 429 2024 Muzaffargarh 5 167 836 2025 Lakhra 1 28 28

The previously proposed interconnection schemes by NTDC for Kohala and Munda

hydropower plants have been modified. The essential transmission additions for the

evacuation of power from the major power plants in the NPSEP between 2020-21 and 20-

25-26 would be as follows:

• For Bhikki

o In-out Lahore-Gatti 500 kV S/C

• For Thar Coal:

o Second ± 600 kV HVDC 2x2000 MW Bipole from Thar to Lahore-South with


o Second 500 kV D/C from Thar to Matiari

o 500 kV D/C Matiari-Moro-R.Y. Khan

o 500 kV S/C Matiari-Jamshoro



o 500 kV D/C from Thar to Karachi (Karachi-South)

• For Bunji 2 and 3

o 500 kV D/C from Bunji to Chilas

o 500 kV D/C from Chilas to Aliot

• For Basha-2

o In-Out Basha-1-Chilas 500 kV D/C and Basha-1 to Mardan (via Kaigah) 500 kV D/C

• For Munda

o In-Out Peshawar-2 (Pajjagi Rd.) – Ghallani 220 kV S/C at Munda

o Munda – Mardan New (Charsaddah) 220 kV D/C

• For Kohala

o In-out Neelum-Jehlum to Aliot 500 kV D/C

• For Palas Valley

o Palas Valley – Mansehra 500 D/C

• For Dasu

o Dasu – Mansehra 500 kV D/C

o Dasu-Palas-Valley 500 kV D/C

• For Lower Spatgah

o In-Out one circuit of Dasu-Palas Valley 500 kV D/C

• For PAEC Karachi (3 x 1000 MW)

o 500 kV D/C PAEC to Karachi-South 500/220 kV S/S

o 500 kV D/C Karachi-South to Karachi-East 500/220 kV S/S

• For Wind Power Cluster at Jhimpir

o In-Out one circuit of Karachi-East to Matiari 500 kV D/C

• For Wind Power Cluster at Gharo

o In-Out Thar-Karachi-East 500 kV D/C

• For Thakot

o Thakot-Mansehra 500 kV D/C

• For Pattan

o Pattan - Thakot 500 kV D/C



o Thakot-Mardan New 500 kV D/C

• For Dhudnial

o Dhudnial - Neelum Jehlum 500 kV D/C

A switching station/substation of 500/220 kV is proposed to be built at Mansehra to collect

power from Dasu and its neighboring Lower Spatgah and Palas Valley HPPs.

As the bulk of the big hydropower plants in the Northern Areas of the Indus and its tributaries

have been added during 2022-2026, and all that power is being collected at the intermediate

switching stations/substations of Aliot, Mansehra and Mardan New, more circuits would be

required to be built from the switching stations to the main load centers as discussed in 8.1.3

below.

8.1.2 New 500/220 kV Grid Stations and Related Transmission Lines of 500 kV: 2021-22 to 2025-26

For the growing demand of the loads during the years 2021 and 2026, new bulk supply

points in terms of 500/220 kV grid stations are required to be added during this period,

especially in the big load centers such as Islamabad, Lahore, Faisalabad and Karachi which

would be integrated in the 500 kV ring to be developed around these cities as follows:

Year Grid Station kV MVA Connections

2022 Islamabad-North

500/220 3x750 In-Out Aliot to Islamabad -West 500 kV D/C at Islamabad

Aliot-Islamabad-North 500 kV D/C

Islamabad-North to Rewat 500kV D/C

2023 Karachi-East 500/220 3x1000 In-Out NKI-Matiari 500 kV D/C at Karachi-East

2023 Lahore-East 500/220 2x1000 In-Out Lahore-North to Lahore-South 500kV D/C at Lahore-East

2023 Mansehra 500/220 3x750 Dasu-Mansehra 500 kV D/C (as mentioned above)

Palas-Valley – Mansehra 500 kV D/C (as mentioned above)

Mansehra - Faisalabad-West 500 kV D/C

Mansehra-Qadirabad 500 kV D/C

Mansehra – Faisalabad -East 500 kV D/C

Mansehra - ISBD-West 500 kV D/C




2023 Karachi South 500/220 3x1000 Karachi-East-Karachi-South D/C (as already mentioned above)

2023 Okara 500/220 3x750 In-out Sahiwal – Lahore South D/C 2024 Bannu 500/220 3x750 Mardan New - Bannu 500 kV D/C

Bannu-Chashma (Nuclear) 500 kV D/C

2024 Sialkot 500/220 3x750 In-Out Aliot-Lahore-North 2nd circuit 500 kV at Sialkot

2024 Faiselabad-East (North)

500/220 3x750 Mansehra - Faisalabad -East 500 kV D/C

Faisalabad-West-Faisalabad-East(North) D/C

Gatti-Faiselabad-East (North) D/C

8.1.3 New 220/132 kV Grid Stations and Related Transmission Lines of 220 kV: 2021-22 to 2025-26

Detailed load capacity analysis has been carried out and attached in Appendix-1.3 to

establish the need for new 220/132 kV grid stations during this period taking into account

firm capacities i.e. considering N-1 contingency of one transformer out of service. When a

grid station hits the maximum firm capacity, a new grid station is proposed in the same

vicinity or extension/augmentations are proposed if space to accommodate more

transformers is available (4 transformers are taken as the maximum number of transformers

at one grid station). Based on this analysis, following are the new 220/132 kV grid stations to

be added in the system during this period

Year Grid Station kV MVA 220 kV Connections

2021 Ghalanai 220/132 3 X 250 Pesh-2 – Ghalanai D/C

2021 Bahter More 220/132 3 X350 ISBD-West to Bahter More 2xD/C

2021 Tandlianwala 220/132 3 X 350 Faisalabad -East(North) to Tandlianwala D/C

T.T. Singh – Tandlianwala D/C

2021 Narwala Rd 220/132 3 X 350 Faisalabad -East(North) to Narwala RD. D/C

Faisalabad -West to Narwala Rd. D/C

2021 Layyah 220/132 3 X2 50 KAPCO-Layyah D/C

2021 Saryab 220/132 3 X 350 In Out Quetta-Mastung D/C

2021 Surab 220/132 3 X250 Mastung-Surab D/C




2022 Pezo 220/132 3 X2 50 D. I. Khan – Pezo D/C

2022 Regi Model Town 220/132 3 X2 50 Jamrud-Regi Model Town D/C

2022 Shahinabad 220/132 3 X 350 Gujranwala-Shahinabad D/C

2022 Jalalpur-Jattan 220/132 3 X 350 Gujrat-Jalalpur-Jattan D/C

2022 Raiwind Road 220/132 3 X 350 Lahore-South - Raiwaind Rd D/C

2022 Shahdra New 220/132 3 X 350 Lahore-N - Shahdra-N D/C

2022 Lulliani 220/132 4 X 350 Lahore-E - Lullyani 2xD/C

Sarfraz Nagar - Lulliani D/C

2022 Model Town 220/132 3 X 350 KLPAT-Model Town 2 S/C Cables

2022 Depalpur 220/132 3 X350 Okara-Depalpur D/C

2022 Sargodha 220/132 3 X250 Ludewala-New-Sargodha D/C

2022 Jaranwala 220/132 3 X250 Faisalabad -(East)North-Jaranwala D/C

2022 Fiedmic 220/132 3 X 250 Faisalabad -(East)North - Fiedmic D/C

2022 Multan City (GIS) 220/132 3 X 350 Qasimpur-Multan City (GIS) D/C

2023 Pesh-City (GIS) 220/132 3 X3 50 Pesh-2 – Pesh-City-GIS 3 S/C Cables

2023 Mingora 220/132 3 X2 50 Chakdara-Mingora D/C

2023 Mominpura 220/132 3 X3 50 Lahore-N - Mominpura D/C

2024 Pajjagi Rd. 220/132 3 X2 50 In-Out Pesh-2 – Ghalanai D/C at Pajjagi Rd.

2024 D. I. Khan - 2 220/132 3 X2 50 D. I. Khan - D. I. Khan-2 D/C

2024 Islamabad-Society (Lohibir)

220/132 3 X 250 IBD-North -Islamabad--Society (Lohibir) D/C

IBD-I-10 to Islamabad-Society (Lohibir) D/C

2024 Kandiaro 220/132 3 X 350 Moro-Kandiaro D/C

2024 Meharr 220/132 3 X2 50 Dadu-Meharr D/C

2024 Jehlum 220/132 2 X 250 Gujrat-Jehlum D/C

Islamabad-North-Jehlum D/C

2024 Miranshah 220/132 2 X 250 Bannu - Miranshah D/C

2025 Charsaddah 220/132 3 X 250 In-Out Mardan New-Munda D/C at Charsaddah

2025 Karol 220/132 3 X 350 Lahore-North To Karol D/C

Karol – Moinpura D/C

2025 Saidpur 220/132 3 X 350 Lahore-South - Saidpur D/C




2025 Shershah 220/132 3 X2 50 In-Out Muzaffergarh-N-Multan

In-Out Muzaffergarh-2-Multan

2025 Bahawalpur-North 220/132 3 X2 50 In-Out Muzaffergar-1-Bahawalpur-N D/C

2025 Khairpur 220/132 3 X 250 Rohri-New - Khairpur D/C

2025 Kohsar 220/132 3 X2 50 T.M. Khan Rd - Kohsar D/C

2025 Gujar Khan 220/132 3 X 350 In-Out Islamabad North-Jehlum at Gujar Khan

2nd D/C ISBD-N-Gujar-Khan D/C

2025 DHA Lahore 220/132 2 X 350 Lahore-East To DHA D/C

2025 Panwan 220/132 2 X 350 Lahore-N To Panwan D/C

2025 Burewala 220/132 3 X 250 Vehari-Burewala D/C

Burewala-Arifwala D/C

2025 Bahawalnagar 220/132 2 X 250 Chishtian-Bahawalnagar D/C

8.1.4 New Transmission Lines for System Reinforcements Required for Normal and N-1 Contingency Conditions: 2021-22 to 2025-26

In addition to the new lines added in the system for evacuation of power from new power

plants and for making connections with the new 500/220/kV and 220/132 kV grid stations,

additional new lines are required to keep the loading on the circuits within the permissible

limits under normal as well as N-1 contingency conditions. The details of such additional

lines to be added in this period are as below:

Year Line kV Type

2022 Mardan-Faisalabad -West 500kV D/C

2022 Ludewala-Faisalabad -West 500kV D/C

2023 Sialkot-New to Sialkot (Sahuwala) 220 kV 2 x D/C

2024 Haveli-Multan 500 kV D/C 2025 Matiari – Moro 500kV D/C



8.1.5 Augmentations and Extensions at 500/220 kV and 220/132 kV Grid

In addition to adding the new grid stations of 500/220 kV and 220/132 kV discussed above,

the capacities of already existing grid stations were enhanced by Augmentations and

Extensions. The Augmentations and Extensions at 500/220 kV for this period are as follows:


2022 Ludewala 500/220 1x750 MVA Extension

2022 Multan 500/220 3x1000 MVA Augmentation

2022 Islamabad-West 500/220 1x750 MVA Extension

2023 Lahore-South 500/220 3x1000 MVA Augmentation

2023 Gujranwala (Gakhar) 500/220 2x750 MVA Augmentation

2022 D. G. Khan 500/220 2x750 MVA Augmentation

2024 Lahore-North 500/220 1x1000 MVA Extension

2025 Faisalabad -West 500/220 3x1000 MVA Augmentation

2022 Sh. Mohammadi (Peshawar) 500/220 3x750 MVA Augmentation

2022 Vehari 500/220 1x750 MVA Extension

2023 Gatti 500/220 4x750 MVA Augmentation

2023 Lahore Old (Sheikhupura) 500/220 4x750 MVA Augmentation

2024 Sahiwal 500/220 1x750 MVA Extension

2022 Shikarpur 500/220 2x750 MVA Augmentation

2025 Shikarpur 500/220 1x750 MVA Extension

2022 Dadu 500/220 2x750 MVA Augmentation

2025 Dadu 500/220 1x750 MVA Extension


2025 D.G. Khan 500/220 1x750 MVA Extension

It can be seen that most of the existing old 500 kV grid stations such as Multan Gatti,

Lahore-Old, Peshawar (Sh. Mohammadi)) and Dadu, have been augmented with new higher

capacity of multiples of 750 MVA or 1000 MVA transformers.

The extensions and augmentation at 220/132 kV grid stations are based on the load

capacity analysis (Appendix-1.3). There are forty eight (48) grid stations of 220/132 kV

where either extension or augmentation has been carried out as listed in detail in Appendix

10.2.




The transmission scheme discussed above was evolved on the basis of load capacity

analysis and detailed load flow analysis carried out for high hydel (low thermal) and low

water (high thermal) conditions for normal (N-0) and contingency (N-1) conditions

respectively.

The study results with connectivity of all the new 500kV and 220 kV grid stations and new

transmission lines proposed for this period have been plotted and attached for HW and LW

seasons in Appendix-4.1 and 4.2 respectively:

Normal (N-0) cases:

Load flow results of normal cases i.e. with no circuits out of service, are attached as follows:


Exhibit-2025-HW-2.0 Results of Southern System of 500 kV


Exhibit-2025-HW-4.0 Results of Mid-Country System of 220 kV


Exhibit-2026-LW-1.0 Results of Southern System of 500 kV



Exhibit-2026-LW-4.0 Results of Mid-Country System of 220 kV


Due to congestion in the drawings, the plotted results of 220 kV network are separated from

500 kV network and divided in 3 parts each for Northern system, Mid-Country system and

Southern system.

The results indicate the same pattern of power flows as in the previous spot years of study

i.e. heavier flows in Northern circuits of 500 kV and 220 kV during HW season and relatively

lighter flows on Southern grid; and vice versa during LW season. The voltages at 500 kV and

220 kV on the entire NTDC system from North to South are within the normal permissible

limits. The power flows on the lines of 500 kV and 220 kV and 500/220kV and 220/132 kV

transformers are also within their rated limits.




The automatic contingency analysis (ACCC) for 220 kV network has been carried out which

indicated some violations requiring reinforcement of the network as described above in

section 8.1.4 With the proposed reinforcements the violations of voltage and line loadings

were eliminated.

Because of the power flow pattern causing more loading on lines on a seasonal basis, the

one-line-out contingency cases of 500 kV system have been carried out for the Northern

system (HW season being the season for heavy loading) whereas for the Southern system

the outages have been performed on LW season respectively due to heavier loading during

LW season..



Exhibit-2025-HW-1.1 Basha-1 to Gabral 500 kV Single Circuit Out

Exhibit-2025-HW-1.2 Gabral to Asrit-K 500 kV Single Circuit Out

Exhibit-2025-HW-1.3 Asrit-K to Mardan-New 500 kV Single Circuit Out

Exhibit-2025-HW-1.4 Basha-1 to K-Asrit 500 kV Single Circuit Out

Exhibit-2025-HW-1.5 K-Asrit to Madyan 500 kV Single Circuit Out

Exhibit-2025-HW-1.6 Madyan to Mardan-New 500 kV Single Circuit Out

Exhibit-2025-HW-1.7 Basha-1 to Mardan-New 500 kV Single Circuit Out

Exhibit-2025-HW-1.8 Basha-1 to Kaigah 500 kV Single Circuit Out

Exhibit-2025-HW-1.9 Kaigah to Mardan-New 500 kV Single Circuit Out

Exhibit-2025-HW-1.10 Pattan to Thakot 500 kV Single Circuit Out

Exhibit-2025-HW-1.11 Thakot to Mardan-New 500 kV Single Circuit Out

Exhibit-2025-HW-1.12 Thakot to Mansehra 500 kV Single Circuit Out

Exhibit-2025-HW-1.13 Dasu to Lower Spatgah 500 kV Single Circuit Out

Exhibit-2025-HW-1.14 Lower Spatgah to Palas 500 kV Single Circuit Out

Exhibit-2025-HW-1.15 Dasu to Palas 500 kV Single Circuit Out

Exhibit-2025-HW-1.16 Palas to Mansehra 500 kV Single Circuit Out

Exhibit-2025-HW-1.17 Dasu to Mansehra 500 kV Single Circuit Out

Exhibit-2025-HW-1.18 Bunji to Chilas 500 kV Single Circuit Out

Exhibit-2025-HW-1.19 Chilas to Suk-Knri 500 kV Single Circuit Out

Exhibit-2025-HW-1.20 Suk-Knri to Aliot-S/S 500 kV Single Circuit Out

Exhibit-2025-HW-1.21 Chilas to Aliot-S/S 500 kV Single Circuit Out



Exhibit-2025-HW-1.22 Dhudnial to N-Jehlum 500 kV Single Circuit Out

Exhibit-2025-HW-1.23 N-Jehlum to Kohala 500 kV Single Circuit Out

Exhibit-2025-HW-1.24 Kohala to Aliot-S/S 500 kV Single Circuit Out

Exhibit-2025-HW-1.25 Mardan-New to FBD-W 500 kV Single Circuit Out

Exhibit-2025-HW-1.26 FBD-W to Haveli 500 kV Single Circuit Out

Exhibit-2025-HW-1.27 Mardan-New to Banu 500 kV Single Circuit Out

Exhibit-2025-HW-1.28 Chashma-Nuc to Ludewala 500 kV Single Circuit Out

Exhibit-2025-HW-1.29 Ludewala to FBD-W 500 kV Single Circuit Out

Exhibit-2025-HW-1.30 Mardan-New to Peshawar-2 500 kV Single Circuit Out

Exhibit-2025-HW-1.31 Tarbela to Ludewala 500 kV Single Circuit Out

Exhibit-2025-HW-1.32 Tarbela to G.Brotha 500 kV Single Circuit Out

Exhibit-2025-HW-1.33 G.Brotha to Ludewala 500 kV Single Circuit Out

Exhibit-2025-HW-1.34 Ludewala to Gatti 500 kV Single Circuit Out

Exhibit-2025-HW-1.35 G.Brotha to FBD-W 500 kV Single Circuit Out

Exhibit-2025-HW-1.36 Mansehra to FBD-W 500 kV Single Circuit Out

Exhibit-2025-HW-1.37 Mansehra to FBD-E 500 kV Single Circuit Out

Exhibit-2025-HW-1.38 Faisalabad -E to Gatti 500 kV Single Circuit Out

Exhibit-2025-HW-1.39 Mansehra to ISBD-W 500 kV Single Circuit Out


Exhibit-2025-HW-1.41 Aliot-s/s to ISBD-N 500 kV Single Circuit Out

Exhibit-2025-HW-1.42 ISBD-N to Rewat-N500 kV Single Circuit Out

Exhibit-2025-HW-1.43 ISBD-W to Rewat-N500 kV Single Circuit Out

Exhibit-2025-HW-1.44 Rewat-N to Gujranwala 500 kV Single Circuit Out

Exhibit-2025-HW-1.45 Mansehra to Qadirabad 500 kV Single Circuit Out

Exhibit-2025-HW-1.46 Qadirabad to Gujranwala 500 kV Single Circuit Out

Exhibit-2025-HW-1.47 Mansehra to Gujranwala 500 kV Single Circuit Out


Exhibit-2025-HW-1.49 Lahore-O to Lahore-South 500 kV Single Circuit Out

Exhibit-2025-HW-1.50 Bhikki to Lahore-O 500 kV Single Circuit Out

Exhibit-2025-HW-1.51 Aliot-S/S to Azad Pattan 500 kV Single Circuit Out

Exhibit-2025-HW-1.52 Azad Pattan to Gujranwala 500 kV Single Circuit Out

Exhibit-2025-HW-1.53 Aliot-s/s to Karot 500 kV Single Circuit Out

Exhibit-2025-HW-1.54 Karot to Gujranwala 500 kV Single Circuit Out

Exhibit-2025-HW-1.55 Gujranwala to Lahore-N 500 kV Single Circuit Out



Exhibit-2025-HW-1.56 Aliot-s/s to Sialkot 500 kV Single Circuit Out

Exhibit-2025-HW-1.57 Sialkot to Lahore-N 500 kV Single Circuit Out

Exhibit-2025-HW-1.58 Aliot-s/s to Gujrat 500 kV Single Circuit Out

Exhibit-2025-HW-1.59 Gujrat to Lahore-N 500 kV Single Circuit Out

Exhibit-2025-HW-1.60 Lahore-N to Lahore-E 500 kV Single Circuit Out

Exhibit-2025-HW-1.61 Tajikistan to Peshawar-2 500 kV HVDC Monopole Out


Exhibit-2026-LW-1.1 Tharcoal-2 to Matiari 500 kV Single Circuit Out

Exhibit-2026-LW-1.2 Tharcoal1 to Matiari 500 kV Single Circuit Out

Exhibit-2026-LW-1.3 Tharcoal1 to Karachi-E 500 kV Single Circuit Out

Exhibit-2026-LW-1.4 Karachi-S to PAEC 500 kV Single Circuit Out

Exhibit-2026-LW-1.5 NTDC Gharo to Karachi-E 500 kV Single Circuit Out

Exhibit-2026-LW-1.6 IMP-Coal to NKI 500 kV Single Circuit Out

Exhibit-2026-LW-1.7 IMP-Coal to AES-Coal 500 kV Single Circuit Out

Exhibit-2026-LW-1.8 AES-Coal to NKI 500 kV Single Circuit Out


Exhibit-2026-LW-1.10 NKI to KDA 500 kV Single Circuit Out

Exhibit-2026-LW-1.11 NKI to Karachi-E500 kV Single Circuit Out

Exhibit-2026-LW-1.12 NTDC-Jhimpir to Matiari 500 kV Single Circuit Out

Exhibit-2026-LW-1.13 Karachi-E to Matiari 500 kV Single Circuit Out



Exhibit-2026-LW-1.16 NKI to Jamshoro 500 kV Single Circuit Out


Exhibit-2026-LW-1.18 Moro to Dadu 500 kV Single Circuit Out

Exhibit-2026-LW-1.19 Dadu to SHKPR500 500 kV Single Circuit Out

Exhibit-2026-LW-1.20 Guddu-NEW to M.Garh 500 kV Single Circuit Out

Exhibit-2026-LW-1.21 Guddu to D. G. Khan 500 kV Single Circuit Out

Exhibit-2026-LW-1.22 Guddu-NEW to Guddu 500 kV Single Circuit Out

Exhibit-2026-LW-1.23 R. Y. Khan to Multan 500 kV Single Circuit Out

Exhibit-2026-LW-1.24 Haveli to FBD-W 500 kV Single Circuit Out

Exhibit-2026-LW-1.25 Haveli to Multan 500 kV Single Circuit Out

Exhibit-2026-LW-1.26 Rousch to Multan 500 kV Single Circuit Out



Exhibit-2026-LW-1.27 Multan to Vehari 500 kV Single Circuit Out

Exhibit-2026-LW-1.28 Sahiwal to Vehari 500 kV Single Circuit Out

Exhibit-2026-LW-1.29 Lahore-South to Okara 500 kV Single Circuit Out

Exhibit-2026-LW-1.30 Tharcosl-2 to Lahore-South 600 HVDC Mono Pole out

Exhibit-2026-LW-1.31 Tharcoal-1 to Lahore-South 600 kV HVDC Monopole Out

Exhibit-2026-LW-1.32 Tharcoal-2 to FBD-W 600 kV HVDC Monopole Out

The normal and N-1 contingency load flow results of 500 kV indicate that the proposed

transmission expansion scheme of 500 kV during 2021-22 and 2025-26, fulfills the criteria of

the Grid Code. The power flows on the intact circuits of 500 kV and 500/220 kV transformers

for each outage are within the limits. The voltage profile on all 500 kV bus bars is also within

the permissible criteria.

The above analysis establishes the fact that the proposed expansion scheme of 500 kV and

220 kV network till 2025-26 is adequate fulfilling the criteria of the Grid Code under normal

and N-1 contingency conditions.




The major generation additions during the period from 2026-27 to 2029-30, include major

blocks of coal-fired power plants at Thar coal fields, nuclear plants and a few hydel and

thermal power plants across the Indus river and mid country respectively. The major plants

are as follows:



Power Plants Type Installed Capacity, MW

Commissioning Year

Tungas Hydro 2000 2026-27 Yulbo Hydro 2400 2026-27 D. I. Khan CC 1414 2026-27 Thar Coal 6000 2027-28 PAEC (Karachi) Nuclear 1000 2027-28 Thar Coal 4800 2028-29 Chashma Nuclear 1000 2028-29 Thar Coal 6000 2029-30 Balloki CC 1414 2029-30 Wind Power(Total) Wind 1600 2026-30

Some old power plants have been considered retired between the period 2016 and 2030 as

proposed in the Generation Expansion Plan as follows:

Year Retiring Power Plant #of Units Unit

Capacity MW

Total MW

2026 Kot Addu 244 2027 KESC-Anoud 12

Muzaffargarh 240 KESC-Bin Qasim 4 177 708 Kohinoor 6 12 72

2028 KESC-IIL 6 19 113 2029 KESC-SGTPS 87

KESC-KGTPS 87 Kot Addu 3 240 721 SEPCOL 6 19 115

The essential transmission additions for the evacuation of power from the major power

plants in NPSEP between 2026-27 and 2029-30 would be as follows:

• For Tungus

o Tungus-Yulbo 500 kV D/C

• For Yulbo

o Yulbo-Bunji 500 kV 3 circuits (One D/C and One S/C)



• For D. I. Khan (CCPP)

o To be connected at D. I. Khan 220 kV grid station already connected to

Bannu, D. I. Khan-2, Pezo, Bhakkar, C1/C2 and C2/C3

• For Chashma (Nuclear)

o To be connected to already constructed Chashma-Nuclear PP at 500 kV

o Chashma-Bannu 500 kV D/C

• For Balloki

o In-Out Lahore-South to Okara (Sahiwal) 500 kV D/C

• For Thar Coal:

o Third and Fourth ± 600 kV HVDC each 2x2000 MW Bipoles from Thar to

Lahore-South with respective converter stations of same capacity for each

Bipole on both ends

o Second and Third ± 600 kV HVDC each 2x2000 MW Bipoles from Thar to

Faiselabad-West with respective converter stations of same capacity for each

Bipole on both ends

o ± 600 kV HVDC 2x2000 MW Bipole from Thar to Multan with respective


o Third and Fourth 500 kV D/C from Thar to Matiari

o Third 500 kV D/C from Thar towards Karachi – East (Upto NTDC-Gharo

which is already connected to Karachi-East via 500 kV D/C)

9.1.2 New 500/220 kV Grid Stations and Related Transmission Lines of 500 kV: 2026-27 to 2030

No new 500/220 kV grid station has been proposed to be constructed at the load centers

during this period. However many extensions and augmentations have been proposed to

enhance the capacity of already envisaged 500/220 kV grid stations. This served the needs

of extra transformation capacity required to cater for the projected loads during this period.

9.1.3 New 220/132 kV Grid Stations and Related Transmission Lines of 500 kV: 2026-27 to 2030

The requirements for new 200/132 kV grid stations for this period were established through

load capacity analysis (Appendix 1.3). These are explained with their proposed sizes and

connectivity schemes as follows:




2027 Islamabad-H-11 220/132 3 X 350 Bahter-More To Islamabad H-11 D/C

2027 Jhang 220/132 3 X 250 Fsbd-W - Jhang D/C

2027 Sahiwal-2 220/132 3 X 350 Yousufwala-Sahiwal-2 D/C

2027 Khanozai 220/132 2 X 250 In-Out Quetta-Loralai D/C

2028 Thal 220/132 3 X2 50 Bannu-Thall D/C

2028 Sialkot-North 220/132 2 X 250 Sialkot 500/220 kV - Sialkot-North D/C

2028 Wazirabad 220/132 2 X 350 Gujrat-Wazirabad D/C

2028 Sunder 220/132 3 X 250 In-Out Lahore-South - Raiwaind Rd. D/C at Sunder

2nd Lahore-South - Sunder D/C

2028 Mianwali 220/132 2 X 350 In-Out C3/C4 - Jauhrabad At Mianwali

2028 Nawabshah 220/132 2 X 250 Moro-Nawabshah D/C

2029 Pasrur 220/132 3 X 350 Sialkot New - Pasrur D/C

2029 Fsbd-City (GTS) 220/132 2 X 350 Gatti - Faisalabad-City (GTS) D/C (cables)

2030 Swabi 220/132 3 X2 50 Mardan New - Swabi D/C

9.1.4 New Transmission Lines for System Reinforcements Required for Normal and N-1 Contingency Conditions: 2026-27 to 2030

Some additional lines would be required other than those proposed earlier for evacuation of

power from new power plants and those required for the interconnection of new grid stations

with the system.

Year Line kV Type

2026 Peshawar-Jamrud 220kV D/C

2026 Peshawar-2 - Peshawar-City 220kV S/C (cable)

2026 Faisalabad – West -Samundri Rd. 220kV D/C

2026 Gatti-Jaranwala Rd. (Reconductor) 220kV D/C

2027 Sibbi-Mastung 220 kV 2D/C 2027 Basha – Bunji 500 kV D/C

9.1.5 Augmentations and Extensions at 500/220 kV and 220/132 kV Grid 2026-27 to 2030

The Augmentations and Extensions at 500/220 kV to enhance the transformation capacity to

meet the additional demand in this period would be as follows:




2026 Guddu 500/220 3x600 MVA Augmentation

2026 Ludewala 500/220 1x750 MVA Extension

2026 Peshawar-2 500/220 1x750 MVA Extension

2027 Multan 500/220 1x1000 MVA Extension

2027 Lahore-South 500/220 1x1000 MVA Extension


2028 Lahore-North 500/220 1x1000 MVA Extension

2028 Lahore-East 500/220 1x1000 MVA Extension

2028 Faisalabad -West 500/220 1x1000 MVA Extension

2028 Faisalabad -East (North) 500/220 1x750 MVA Extension

2029 Shikarpur 500/220 1x750 MVA Extension

2028 Karachi-South 500/220 1x1000 MVA Extension

2028 Karachi-East 500/220 1x1000 MVA Extension

2030 R. Y. Khan 500/220 1x600 MVA Extension

2030 Moro 500/220 1x750 MVA Extension

Augmentations and Extensions at existing 220/132 kV grid stations are based on the load

capacity analysis (Appendix-1.3). There would be nineteen (19) such

extensions/augmentations required in this period as described in detail at the end of

Appendix-10.3

9.2 Load Flow Results of the year 2030

The proposed transmission schemes as discussed above are based on load capacity

analysis and detailed load flow simulations for high hydel (low thermal) and low water (high

thermal) have been performed for normal (N-0) and contingency (N-1) conditions for each

case. The year 2030 being the ultimate spot year of this study, these load flow simulation

cases contain the entire scope of proposed transmission expansion under the purview of this

study. The total transmission expansion plan is seen in these simulations.

The plotted results have been placed in Appendix 5.1 and 5.2 respectively.



Normal (N-0) cases:

Load flow results of normal cases i.e. with no circuits out of service, are attached as follows:




Exhibit-2030-HW-4.0 Results of Mid-Country System of 220 kV





Exhibit-2030-LW-4.0 Results of Mid-Country System of 220 kV


The results indicate that the pattern of power flow set during the earlier years of study

changes in this year because of major retirements of old generating units in mid country and

the South. Even in high water months the demand of the Southern grid up to R. Y. Khan and

D. G. Khan is met by transmitting more power from the South (coal based thermal power

plants at Thar and Karachi including the nuclear power plants and significant wind power at

Jhimpir and Gharo wind power clusters).

However the power flows on the lines remain within the rated limits. Also the voltage on bus

bars of 500 and 220 kV has been found within the permissible limits.


The automatic contingency analysis (ACCC) for 220 kV network has been carried out and

wherever it indicated violations of rated limits of line loadings the network was reinforced as

described above in section 8.1.4. With the proposed reinforcements the violations of voltage

and line loadings were eliminated.

The one-line-out contingency cases of 500 kV system have been carried out for the Northern

system for HW season and for the Southern system the outages have been performed on

LW season. The plotted results are placed in Appendices 5.1 and 5.2 as follows:




Exhibit -2030-HW-1.1 Basha-1 to Gabral 500kV Single Circuit Out

Exhibit -2030-HW-1.2 Gabral to Asrit-K 500kV Single Circuit Out

Exhibit -2030-HW-1.3 Asrit-K to Mardan-New 500kV Single Circuit Out

Exhibit -2030-HW-1.4 Basha-1 to K-Asrit 500kV Single Circuit Out

Exhibit -2030-HW-1.5 K-Asrit to Madyan 500kV Single Circuit Out

Exhibit -2030-HW-1.6 Madyan to Mardan-New 500kV Single Circuit Out

Exhibit -2030-HW-1.7 Basha-1 to Mardan-New 500kV Single Circuit Out

Exhibit -2030-HW-1.8 Basha-1 to Kaigah 500kV Single Circuit Out

Exhibit -2030-HW-1.9 Kaigah to Mardan-New 500kV Single Circuit Out

Exhibit -2030-HW-1.10 Pattan to Thakot 500kV Single Circuit Out

Exhibit -2030-HW-1.11 Thakot to Mardan-New 500kV Single Circuit Out

Exhibit -2030-HW-1.12 Thakot to Mansehra 500kV Single Circuit Out

Exhibit -2030-HW-1.13 Dasu to Lower Spatgah 500kV Single Circuit Out

Exhibit -2030-HW-1.14 Lower Spatgah to Palas 500kV Single Circuit Out

Exhibit -2030-HW-1.15 Dasu to Palas 500kV Single Circuit Out

Exhibit -2030-HW-1.16 Palas to Mansehra 500kV Single Circuit Out

Exhibit -2030-HW-1.17 Dasu to Mansehra 500kV Single Circuit Out

Exhibit -2030-HW-1.18 Bunji to Chilas 500kV Single Circuit Out

Exhibit -2030-HW-1.19 Chilas to Suk-Knri 500kV Single Circuit Out

Exhibit -2030-HW-1.20 Suk-Knri to Aliot-S/S 500kV Single Circuit Out

Exhibit -2030-HW-1.21 Chilas to Aliot-S/S 500kV Single Circuit Out

Exhibit -2030-HW-1.22 Dhudnial to N-Jehlum 500kV Single Circuit Out

Exhibit -2030-HW-1.23 N-Jehlum to Kohala 500kV Single Circuit Out

Exhibit -2030-HW-1.24 Kohala to Aliot-S/S 500kV Single Circuit Out

Exhibit -2030-HW-1.25 Bunji to Basha-1 500kV Single Circuit Out

Exhibit -2030-HW-1.26 Yulbu to Bunji 500kV Single Circuit Out

Exhibit -2030-HW-1.27 Tungus to Yulbu 500kV Single Circuit Out

Exhibit -2030-HW-1.28 Peshawar to Peshwar-2 500kV Single Circuit Out

Exhibit -2030-HW-1.29 Mardan-New to FBD-W 500kV Single Circuit Out

Exhibit -2030-HW-1.30 FBD-W to Haveli 500kV Single Circuit Out

Exhibit -2030-HW-1.31 Mardan-New to Banu 500kV Single Circuit Out

Exhibit -2030-HW-1.32 Chashma-Nuc- Ludewala 500kV Single Circuit Out

Exhibit -2030-HW-1.33 Ludewala to FBD-W 500kV Single Circuit Out



Exhibit -2030-HW-1.34 Mardan-New to Peshwar-2 500kV Single Circuit Out

Exhibit -2030-HW-1.35 Tarbela to Ludewala 500kV Single Circuit Out

Exhibit -2030-HW-1.36 Tarbela to G.Brotha 500kV Single Circuit Out

Exhibit -2030-HW-1.37 G.Brotha to Ludewala 500kV Single Circuit Out

Exhibit -2030-HW-1.38 Ludewala to Gatti 500kV Single Circuit Out

Exhibit -2030-HW-1.39 G.Brotha to FBD-W 500kV Single Circuit Out

Exhibit -2030-HW-1.40 Mansehra to FBD-W 500kV Single Circuit Out

Exhibit -2030-HW-1.41 Mansehra to FSBD -E500kV Single Circuit Out

Exhibit -2030-HW-1.42 Mansehra to ISBD-W 500kV Single Circuit Out

Exhibit -2030-HW-1.43 Tarbela to ISBD-W 500kV Single Circuit Out

Exhibit -2030-HW-1.44 Aliot-S/S to ISBD-N 500kV Single Circuit Out

Exhibit -2030-HW-1.45 ISBD-N to Rewat-N 500kV Single Circuit Out

Exhibit -2030-HW-1.46 ISBD-W to Rewat-N 500kV Single Circuit Out

Exhibit -2030-HW-1.47 Rewat-N to Gujranwala 500kV Single Circuit Out

Exhibit -2030-HW-1.48 Mansehra to Qadirabad 500kV Single Circuit Out

Exhibit -2030-HW-1.49 Qadirabad to Gujranwala 500kV Single Circuit Out

Exhibit -2030-HW-1.50 Mansehra to Gujranwala Single Circuit Out

Exhibit -2030-HW-1.51 Gujranwala to Lahore-O500kV Single Circuit Out

Exhibit -2030-HW-1.52 Bhikki to Lahore-O 500kV Single Circuit Out

Exhibit -2030-HW-1.53 Aliot-S/S to Azad Pattan 500kV Single Circuit Out

Exhibit -2030-HW-1.54 Azad Pattan -Gujranwala 500kV Single Circuit Out

Exhibit -2030-HW-1.55 Aliot-S/S to Karot 500kV Single Circuit Out

Exhibit -2030-HW-1.56 Karot to Gujranwala 500kV Single Circuit Out

Exhibit -2030-HW-1.57 Gujranwala to Lahore-N 500kV Single Circuit Out

Exhibit -2030-HW-1.58 Aliot-S/S to Sialkot 500kV Single Circuit Out

Exhibit -2030-HW-1.59 Sialkot to Lahore-N 500kV Single Circuit Out

Exhibit -2030-HW-1.60 Aliot-S/S to Gujrat 500kV Single Circuit Out

Exhibit -2030-HW-1.61 Gujrat to Lahore-N 500kV Single Circuit Out

Exhibit -2030-HW-1.62 Lahore-N to Lahore-E 500kV Single Circuit Out

Exhibit -2030-HW-1.63 Lahore-South to Lahore-E 500kV Single Circuit Out

Exhibit -2030-HW-1.64 Balloki to Lahore-South 500kV Single Circuit Out

Exhibit -2030-HW-1.65 Tajikistan to Peshwar-2 500kV HVDC Monopole Out



Outages for LW season (Appendix 5.2)

Exhibit -2030-LW-1.1 Tharcoal-2 to Matiari 500 kV Single Circuit Out



Exhibit -2030-LW-1.4 Tharcoal1 to Matiari 500 kV Single Circuit Out

Exhibit -2030-LW-1.5 Matiari to Moro 500 kV Single Circuit Out

Exhibit -2030-LW-1.6 Tharcoal2 to KDA 500 kV Single Circuit Out

Exhibit -2030-LW-1.7 PAEC-1 to Karachi-South 500 kV Single Circuit Out

Exhibit -2030-LW-1.9 IMP-Coal to NKI 500 kV Single Circuit Out

Exhibit -2030-LW-1.9 ASE-Coal to NKI 500 kV Single Circuit Out

Exhibit -2030-LW-1.10 HUB to NKI 500 kV Single Circuit Out

Exhibit -2030-LW-1.11 KDA to NKI 500 kV Single Circuit Out

Exhibit -2030-LW-1.12 NKI to Karachi-East 500 kV Single Circuit Out

Exhibit -2030-LW-1.13 Karachi-South to Karachi-East 500 kV Single Circuit Out

Exhibit -2030-LW-1.14 NTDC-Gharo-Karachi-East 500 kV Single Circuit out

Exhibit -2030-LW-1.15 NTDC-Jhimpir-Karachi-East 500 kV Single Circuit Out

Exhibit -2030-LW-1.16 NTDC-Jhimpir to Matiari 500 kV Single Circuit Out

Exhibit -2030-LW-1.17 Jamshoro to Matiari 500 kV Single Circuit Out

Exhibit -2030-LW-1.18 Jamshoro to Dadu 500 kV Single Circuit Out

Exhibit -2030-LW-1.19 Dadu to Moro 500 kV Single Circuit Out

Exhibit -2030-LW-1.20 Dadu to Shikarpur 500 kV Single Circuit Out

Exhibit -2030-LW-1.21 Shikarpur to Guddu 500 kV Single Circuit Out

Exhibit -2030-LW-1.22 Moro to R. Y. Khan 500 kV Single Circuit Out

Exhibit -2030-LW-1.23 Guddu to Guddu-New500 kV Single Circuit Out

Exhibit -2030-LW-1.24 M.Garh to D. G. Khan 500 kV Single Circuit Out

Exhibit -2030-LW-1.25 M.Garh to Multan 500 kV Single Circuit Out

Exhibit -2030-LW-1.26 Multan to Haveli 500 kV Single Circuit Out

Exhibit -2030-LW-1.27 Haveli to M.Garh 500 kV Single Circuit Out

Exhibit -2030-LW-1.28 Rousch to Multan 500 kV Single Circuit Out

Exhibit -2030-LW-1.29 Multan to Vehari 500 kV Single Circuit Out

Exhibit -2030-LW-1.30 Sahiwal to Vehari 500 kV Single Circuit Out

Exhibit -2030-LW-1.31 Balloki to Okara 500 kV Single Circuit Out

Exhibit -2030-LW-1.32 Lahore-South to Sahiwal 500 kV Single Circuit Out

Exhibit -2030-LW-1.33 Tharcoal-2 to Lahore-South 600 kV HVDC Monopole Out



Exhibit -2030-LW-1.34 Tharcoal-1 to Lahore-South 600 kV HVDC Monopole Out

Exhibit -2030-LW-1.35 Tharcoal-3 to Lahore–South 600 kV HVDC Monopole Out

Exhibit -2030-LW-1.36 Tharcoal-2 to FBD-W 600 kV HVDC Monopole Out

Exhibit -2030-LW-1.37 Tharcoal-1 to FBD-W 600 kV HVDC Monopole Out

Exhibit -2030-LW-1.38 Tharcoal-4 to FBD-W 600 kV HVDC Monopole out

Exhibit -2030-LW-1.39 Tharcoal-4 to Multan 600 kV HVDC Monopole Out

The normal and N-1 contingency load flow results of 500 kV indicate that the overall

transmission expansion scheme proposed up to the ultimate year of 2030 fulfills the system

demand remaining within the rated limits of loadings on lines and transformers, and within

permissible voltages on bus bars for normal as well as N-1 contingency conditions.

The above analysis establishes the fact that the overall transmission expansion plans of 500

kV and 220 kV network proposed till the ultimate year of 2030 are adequate fulfilling the

criteria of Grid Code under normal and N-1 contingency conditions.

The entire expansion plan of 500 kV and 220 kV upto the ultimate year 2030 is shown in the map placed in Figure 9.1.



Figure 9-1 500/220 kV System In the Ultimate Year 2030



10 SHORT CIRCUIT ANALYSIS

10.1 Significance of Short Circuit Analysis

Short circuit analysis is carried out to calculate the fault currents for balanced and unbalanced faults on the system; the most common of them are three-phase to ground faults (balanced) and single-phase to ground faults (unbalanced), usually symmetrical because most of the equipment is rated for symmetrical faults.

The objectives of the maximum fault current calculations are:

a) Determine the rating of rupturing capacity of the breakers to be installed at the new grid

stations or switching stations to connect to new power plants to evacuate their power to

the grid or to feed the power at the load centers received from power plants through

transmission lines.

b) Determine the ratings of the switchgear and other equipment of a new grid station or a

switching station such as disconnect-switches, bus bars, sectionalizers or couplers.

CTs. VTs etc.

c) Check if the ratings of the existing breakers and other switchgear of an existing grid

station or switching station are not violated with the increase of fault current

contributions from new power plants, new lines or transformers going to be installed in

the system especially in its close vicinity

d) Protection coordination of the relays at new or existing grid stations or switching stations

to operate the breakers to isolate the faulted equipment within the specified rated time

interval

e) Fault levels in terms of MVA determine the short circuit strength of the system at a

specific node in the system.

f) Determine the short circuit impedance of a specific node in the system. This is used in

the calculations of relay coordination and developing system equivalent sources for

modeling of a reduced network for electromagnetic transient analysis.

10.2 Methodology and Assumptions for Maximum Fault Current Calculations

Maximum fault current would occur if the maximum fault current contributions combine at a fault location and that would happen if the maximum sources of fault currents are modeled in the system. Since this study is focused on a wide range of the entire expansion of generation and transmission including the hydropower plants in the north and coal based



Thar coal filed projects, therefore maximum fault current contributions from all the power plants from North to south have been included. Two spot years of 2020 and 2030 have been modeled to take into account the fault contributions of all proposed power plants in the plan period for determining the ultimate sizes of switchgear of the grid stations/switching stations to be constructed for the evacuation of power from the power plants and the receiving end grid stations located in the load centers.

The software PSS/E® has been used for short circuit analysis which provides the methodology of maximum fault current calculations as per IEC 909 and IEC 60909 standards. The maximum fault currents have been calculated with the following assumptions under IEC909:

a) Bus Voltages to be equal to 1.1 Per Unit (i.e. 10 % higher than nominal) to cover the

upper limit of operation and the upper design limit as per NTDC specifications

b) Set tap ratios to unity

c) Set line charging to zero

d) Set shunts to zero in positive sequence

The initial runs of short circuit simulations indicated very high fault currents at large

hydropower plants such as Bunji, Basha, Yulbo, Tungus which are grouped together, and at

Thar coal field where current sources are quite closely grouped. For hydropower plants, due

to constraints of transmission corridors, they must be grouped as described. However for the

Thar coal power plants, because the major evacuation of power is via HVDC lines, the

different blocks of power plants can be kept isolated electrically to mitigate the fault levels

within the available standard breaker ratings of 63 kA. Similarly at bus bars of large grid

stations of 500/220 kV and 220.132 kV where many lines are terminating, the fault currents

were revealed to be very high.

As a standard measure of mitigating the fault levels, the following are assumed and

recommended:

a) The reactance of 50/220 kV and 220/132 kV transformers = 20 to 25 %

b) The bus bars of 500 kV and 220 kV which are normally breaker-and-half in the NTDC

system should be split into two groups at each grid station such that all the lines and

transformers should not be connected to one electrical node.



10.3 Fault Current Calculations of the year 2020

The PSS/E® files used for load flow simulations for the year 2020 were enriched with the

sequence data of the generators, lines and transformers to make the files ready for fault

current calculations. The maximum generation dispatches and network conditions of the

year 2020 have been simulated to calculate the maximum fault currents of 3-phase and

1-phase faults assumed at each bus (or split buses) of 500 kV and 220 kV. The simulations

were run using the IEC 909 standards. The fault levels thus calculated for all 500kV and

220kV bus bars have been tabulated in Appendix-6.

Just to establish the fact that the assumptions mentioned above have mitigated the fault

levels within the industry standard ratings of circuit breakers, the fault levels of the ten

highest grid stations of 500 kV bus bars are listed as follows:

Bus No. Bus Name Bus

Voltage Short Circuit Levels

(kA)

(kV) 3-Phase 1-Phase

6 Aliot 500 39.7 33.7 20 Tarbela 500 44.1 46.3 21 ISBD-W 500 39.8 30.0 24 Gujranwala 500 38.6 29.0 25 G.Brotha 500 40.0 34.9 30 Lahore-O 500 38.2 29.6 40 Gatti 500 41.6 30.5 41 Faisalabad -W 500 44.1 35.1 42 Haveli 500 37.8 38.3 85 Tharcoal 500 39.6 46.2

Tarbela, Ghazi Brotha, Gatti and Faiselabad–West are exceeding 40 kA. Therefore it is

imperative to make sure that at these grid stations the switchgear must be replaced, if not

yet replaced, by switchgear of 50 kA or 63 kA short circuit rating before the year 2020.

NTDC keeps on augmenting the switchgear of their existing grid stations with higher ratings

and the top ten grid stations highlighted above should now be in their priority list to upgrade

the switchgear.

The top 10 bus bars in terms of fault levels of 220 kV are as follows:



Bus No. Bus Name

Bus Voltage

Short Circuit Levels (kA)


212 ISBD-W-1 220 39.9 33.0 215 IBD.P.Rd 220 42.2 32.8 245 Gujranwala 220 44.4 37.5 300 Lahore-1 220 44.0 38.5 303 Lahore-South 220 40.2 33.9 350 Yousafwala 220 39.2 35.7 444 Faisalabad -W 220 44.8 38.3 500 Multan-1 220 39.5 32.5 530 M.Garh-1 220 41.9 43.2 600 Guddu 220 41.6 45.4

From the top 10 fault levels of 220 kV bus bars, almost all of them are crossing 40 kA by the

year 2020. Therefore it is imperative to make sure that at these grid stations the switchgear

must be replaced, if not yet replaced, by the switchgear of 50 kA or 63 kA short circuit rating.

10.4 Fault Current Calculations of the year 2030

This is the ultimate year of the study period. The same PSS/E files used for load flow

simulations for the year 2030 were enriched with the sequence data of the generators, lines

and transformers to make the files ready for fault current calculations. The maximum

generation dispatches and network conditions of the year 2030 have been simulated to

calculate the maximum fault currents of 3-phase and 1-phase faults assumed at each bus

(or split buses) of 500 kV and 220 kV. The simulations were run using the IEC 909

standards. The fault levels thus calculated for all 500 kV and 220 kV bus bars have been

tabulated in Appendix-7.

The 500 kV bus bars found to have fault levels more than 50 kA, either 3-phase or 1-phase

or both, have been picked up from Appendix-7.1 as follows:



Sr. No. Bus No. Bus Name

Bus Voltage



1 3 Bunji 500.0 51.7 49.6

2 64 Bunji-2 500.0 55.0 53.7

3 4 Chilas 500.0 56.2 46.7

4 6 Aliot-S/S-1 500.0 51.5 42.7

5 67 Aliot-S/S-2 500.0 51.6 41.6

6 9 Thakot 500.0 57.3 54.6

7 14 Yulbu 500.0 53.5 53.8

8 20 Tarbela 500.0 51.7 52.3

9 22 Rewat-N 500.0 54.5 39.1

10 37 Ludewala 500.0 50.7 31.9

11 39 Faisalabad -E 500.0 57.5 38.9

12 40 Gatti 500.0 60.0 40.9

13 41 Faisalabad -W-1 500.0 58.3 38.9

14 49 Faisalabad -W-2 500.0 52.9 34.4

15 42 Haveli 500.0 52.4 48.1

16 85 Tharcoal1 500.0 49.0 55.4 17 84 Tharcoal2 500 43.4 50.0 18 91 NKI-1 500.0 53.1 44.7

19 69 NKI-2 500.0 51.9 42.8

20 80 Jamshoro 500.0 51.5 36.8

21 95 Matiari 500.0 50.0 34.4

22 214 Kohala 500.0 51.2 47.1

23 93 Karachi-E-1 500.0 50.0 38.2

The fault levels on 23 bus bars are more than 50 kA but less than 63 kA which is the next

available industry standard size. It is suitable to adopt 63 kA for these substations. Therefore

it is imperative to make sure that the switchgear of the rating of 63 kA must be installed (for

new substations) or replaced (for old substations) before the year 2030.

The 220 kV bus bars found to have short circuit levels more than 40 kA, either 3-phase or

1-phase or both, have been picked up from Appendix-7.2 as follows:




Bus Voltage



1 100 Peshawar 220 44.8 35.9

2 151 Peshwr-2 220 47.4 36.8

3 154 Mardan-N-1 220 41.1 32.9

4 155 Mardan-N-2 220 41.1 32.8

5 200 Tarbela 220 53.1 51.9

6 202 Bahter More 220 41.1 27.8

7 207 ISND-N 220 43.3 35.3

8 212 ISBD-W 220 54.4 42.7

9 215 IBD.P.RD 220 55.4 40.9

10 218 ISBD-W-2 220 54.0 41.4

11 230 Mangla 220 40.2 39.6

12 242 Gujrat 220 47.1 34.4

13 245 Gujranwala 220 52.6 37.5

14 250 K.S.K-1 220 59.3 45.6

15 251 K.S.K-2 220 42.3 32.4

16 252 Karol 220 42.7 29.6

17 260 Lahore-N-1 220 59.5 48.2

18 261 Lahore-N-2 220 41.5 34.6

19 295 Lahore-E 220 56.5 45.7

20 300 Lahore-1 220 49.4 43.1

21 303 Lahore-South 220 60.5 50.9

22 304 Lahore-2 220 43.5 37.8

23 310 Shalimar 220 40.3 28.3

24 312 Mominpura 220 44.4 31.6

25 320 Ravi 220 41.3 30.9

26 340 Okara220 220 43.8 37.6

27 360 Ludewala 220 55.5 44.9

28 405 Faisalabad -N 220 52.6 42.7

29 430 Narwala Rd. 220 40.2 28.3

30 443 FBD-W-2 220 40.7 32.4

31 444 FBD-W-1 220 42.3 34.7




Bus Voltage



32 500 Multan 220 46.7 44.6

33 501 Multan-2 220 48.6 41.9

34 520 Piranghaib 220 40.7 34.0

35 620 Shkpr220 220 40.9 35.0

36 840 T. M. Kh. Rd 220 42.1 33.3

37 9256 NTDC Gharo 220 45.3 39.0

38 9429 NTDC Jhimpir 220 51.1 42.8

39 900 KDA33-1 220 44.8 38.9

40 901 KDA33-2 220 43.8 37.1

41 9934 ICI 220 40.9 38.4

42 9966 BinQasim-1 220 41.2 38.6

43 9967 BinQasim-2 220 40.6 38.1

From the above list, 43 grid stations bus bars of 220 kV are crossing 40 kA by the year 2030.

Also it is revealed that at 12 grid stations, the fault levels at 220 kV are higher than 50 kA i.e.

Tarbela, ISBD-W, IBD.P.RD, ISBD-W-2, Gujranwala, K.S.K-1, Lahore-N-1, Lahore-E,

Lahore-South, Ludewala, Faisalabad -N, NTDC Jhimpir. It is recommended to go for

• 50 kA rating for those grid stations which exceed 40 kA but are much less than 50 kA

to leave enough margin

• 63 kA for those where the fault levels are reaching close to and/or exceeding 50 kA.

11 TRANSIENT STABILITY STUDIES

In the NPSEP, significant amounts of generation have been added with a varied nature of

generating technologies; hydel, nuclear, wind and thermal generation based on coal fired

steam and combined cycles etc. The generating unit sizes vary from medium to very large

sizes connecting to the system through medium to long HVAC transmission lines and HVDC

lines.

The performance of the proposed transmission schemes have been tested for steady state

conditions of the system under normal and contingency cases by extensive load flow studies

already discussed. However the robustness of the system has to be checked for transient /

dynamic behavior under disturbed conditions of the system.



Transient stability studies have been performed for the years 2020 and 2030 as follows:

• 3-phase faults to be cleared in 5 cycles followed by the tripping of a heavily loaded

500 kV circuit emanating from that bus

• All the loads were modeled as static loads with maximum stringent assumptions of

100 % constant current for active power and 100 % constant impedance for reactive

power.

• Power System Stabilizers (PSS) were assumed with all the new proposed generating

units and at some existing power plants South of Multan.

• Fault locations at 500 kV grid stations North of Gatti and Lahore for high water case

and South of Lahore/Gatti for low water case because of heavier power flows on the

lines in each respective season.

• Run simulation nearly 9 seconds after fault clearing (total simulation time = 10

seconds)

• The values monitored and recorded in the simulations are:

o Rotor Angles of Generators,

o Power flow swings on the healthy circuit or circuits impacted to carry

maximum power flow due to the trip of the faulted circuit.

o Voltage

o Frequency

All the results of the stability simulations are attached in Appendices 8 and 9 for year 2020

and 2030 respectively.

11.1 Stability Studies for the year 2020

The transient stability simulations have been carried out using the same load flow cases of

high water (HW) and low water (LW) for 2020 and 2021 respectively. The plotted results of

the simulations for 2020 are attached as Appendix-8. The details of the faults and the

outages and description of respective plots are as follows:

High Water-2020 Cases:

For each case representing a fault location, four subplots are provided in each page

Appendix-8, corresponding to:



• Rotor angle plots for selected generators

• Line flows for a line in the vicinity of the fault that is heavily loaded following the

outage of the faulted circuit (usually a parallel circuit to the outaged circuit),

• Bus voltages in the vicinity of the fault,

• System frequency

The following table summarizes the results:

Fault Location Figure No. Post-fault Outage Performance

Basha 500kV 20H.1 Basha - Gabral 500kV Stable

Gabral 500kV 20H.2 Gabral - Asrit-K 500kV Stable

Asrit-K 500kV 20H.3 Asrit-K - Madyan 500kV Stable

Asrit-K 500 kV 20H.4 Asrit-K - Mardan 500 kV Stable

Bunji 500 kV 20H.5 Bunji - Chilas 500 kV Stable

Chilas 500 kV 20H.6 Chilas - Aliot 500 kV Stable

Suki Kinari 500 kV 20H.7 Suki Kinari - Aliot 500 kV Stable

Neelum-Jehlum 500 kV 20H.8 Neelum Jehlum - Aliot 500 kV Stable

Aliot 500 kV 20H.9 Aliot - ISBD-W 500 kV Stable

Aliot 500 kV 20H.10 Aliot - Azad Pattan 500 kV Stable

Aliot 500 kV 20H.11 Aliot - Gujrat 500 kV Stable

Karot 500 kV 20H.12 Karot - Gujranwala 500 kV Stable

Azad Pattan 500 kV 20H.13 Azad Pattan - Gujranwala 500 kV Stable

Tarbela 500 kV 20H.14 Tarbela - G.Brotha 500 kV Stable

Tarbela 500 kV 20H.15 Tarbela - ISBD-W 500 kV Stable

Tarbela 500 kV 20H.16 Tarbela - Ludewala 500 kV Stable

G-Brotha 500 kV 20H.17 G-Brotha - Ludewala 500 kV Stable

G-Brotha 500 kV 20H.18 G-Brotha - FBD-W 500 kV Stable

Chashma-Nuc 500 kV 20H.19 Chashma-Nuc - Ludewala 500 kV Stable

Ludewala 500 kV 20H.20 Ludewala - Gatti 500 kV Stable

Haveli 500 kV 20H.21 Haveli - M.Garh 500 kV Stable

FBD-W 500 kV 20H.22 FBD-W - Multan 500 kV Stable

ISBD-W 500 kV 20H.23 ISBD-W - Tarbela 500 kV Stable

ISBD-W 500 kV 20H.24 ISBD-W - Rewat-N 500 kV Stable

Gujranwala 500 kV 20H.25 Gujranwala - Lahore-O 500 kV Stable




Lahore-O 500 kV 20H.26 Lahore-O - Gujranwala 500 kV Stable

Lahore-N 500 kV 20H.27 Lahore-N - Aliot 500 kV Stable

Lahore-South 500 kV 20H.28 Lahore-South - Lahore-N 500 kV Stable

Lahore-South 500 kV 20H.29 Lahore-South - Sahiwal 500 kV Stable

Low Water-2021 Cases:

The following table summarizes the results:


FBD-W 500 kV 20T.1 FBD-W - Gatti 500 kV Stable

Lahore-South 500 kV 20T.2 Lahore-South- Lahore-N 500 kV Stable

Tharcoal 500 kV 20T.3 Tharcoal - Matiari 500 kV Stable

Tharcoal 500 kV 20T.4 Tharcoal - KDA 500 kV Stable

Imp-Coal 500 kV 20T.5 Imp-Coal - NKI 500 kV Stable

AES-Coal 500 kV 20T.6 AES-Coal - NKI 500 kV Stable

KDA 500 kV 20T.7 KDA - NKI 500 kV Stable

HUB 500 kV 20T.8 HUB - NKI 500 kV Stable

Matiari 500 kV 20T.9 Matiari - Jamshoro 500 kV Stable

Jamshoro 500 kV 20T.10 Jamshoro - Dadu 500 kV Stable

Guddu 500 kV 20T.11 Guddu - D.G. Khan 500 kV Stable

Multan 500 kV 20T.12 Multan - Vehari 500 kV Stable

As seen above, for the 2020-21 scenarios, 41 stability cases were analyzed and instability

issues were not observed.

11.2 Stability Studies for the year 2030

This is the ultimate year of the study period and has been analyzed in detail to test the

robustness of the proposed transmission expansion plan for the disturbed transient /

dynamic conditions of the system. The plotted results of the simulations for 2030 are

attached as Appendix-9. The details of the faults and the outages and description of

respective plots are shown in a similar fashion to those for the year 2020 as follows:



High Water-2030 Cases:


Basha 500 kV 30H.1 Basha - Gabral 500 kV Stable

Asrit-K 500 kV 30H.2 Asrit-K - Mardan 500 kV Stable

Basha 500 kV 30H.3 Basha - Kaigah 500 kV Stable

Kaigah 500 kV 30H.4 Kaigah - Mardan 500 kV Stable

Madyan 500 kV 30H.5 Madyan - Mardan 500 kV Stable

Pattan 500 kV 30H.6 Pattan to Thakot 500 kV Stable

Thakot 500 kV 30H.7 Thakot - Mansehra 500 kV Stable

Dasu 500 kV 30H.8 Dasu - Mansehra 500 kV Stable

Palas 500 kV 30H.9 Palas - Mansehra 500 kV Stable

Tungus 500 kV 30H.10 Tungus - Yulbu 500 kV Stable

Yulbu 500 kV 30H.11 Yulbu - Bunji 500 kV Stable

Bunji 500 kV 30H.12 Bunji - Chilas 500 kV Stable

Chilas 500 kV 30H.13 Chilas - Aliot 500 kV Stable

Suki-Kinari 500 kV 30H.14 Suki-Kinari - Aliot-S/S 500 kV Stable

Dhudnial 500 kV 30H.15 Dhudnial - Neelum-Jehlum 500 kV Stable

N-Jehlum 500 kV 30H.16 N-Jehlum - Kohala 500 kV Stable

Kohala 500 kV 30H.17 Kohala - ALIOT-S/S 500 kV Stable

Faisalabad-W 500 kV 30H.18 Faisalabad -W - Mardan 500 kV Stable

Mardan 500 kV 30H.19 Mardan - Banu 500 kV Stable

Chashma 500 kV 30H.20 Chashma-NUC - Ludewala 500 kV Stable

Peshawar 500 kV 30H.21 Peshawar - Mardan 500 kV Stable

Tarbela 500 kV 30H.22 Tarbela - G.Brotha 500 kV Stable

G.Brotha 500 kV 30H.23 G.Brotha - Ludewala 500 kV Stable

Mansehra 500 kV 30H.24 Mansehra - FBD-W 500 kV Stable

FBD-E 500 kV 30H.25 FBD-E - Mansehra 500 kV Stable

Gatti 500 kV 30H.26 Gatti - Ludewala 500 kV Stable

ISBD-W 500 kV 30H.27 ISBD-W - Mansehra 500 kV Stable

ISBD-W 500 kV 30H.28 ISBD-W - Rewat-N 500 kV Stable

Rewat-N 500 kV 30H.29 Rewat-N - Gujranwala 500 kV Stable

Mansehra 500 kV 30H.30 Mansehra - Gujranwala 500 kV Stable

Qadirabad 500 kV 30H.31 Qadirabad - Gujranwala 500 kV Stable




Aliot-S/S 500 kV 30H.32 Aliot-S/S - Azad Patan 500 kV Stable

Azad Patan 500 kV 30H.33 Azad Patan - Gujranwala 500 kV Stable

Karot 500 kV 30H.34 Azad Karot - Gujranwala 500 kV Stable

Aliot-S/S 500 kV 30H.35 Trip Aliot-S/S - Sialkot 500 kV Stable

Lahore-N 500 kV 30H.36 Lahore-N - Gujranwala 500 kV Stable

Gujranwala 500 kV 30H.37 Gujranwala - Lahore-O 500 kV Stable

Lahore-O 500 kV 30H.38 Lahore-O - Gujranwala 500 kV Stable

Lahore-E 500 kV 30H.39 Lahore-E - Lahore-South 500 kV Stable

Balloki 500 kV 30H.40 Balloki to Lahore-South 500 kV Stable

Low Water-2030 Cases:


Haveli 500 kV 30T.1 Haveli - M.Garh 500 kV Stable

Multan 500 kV 30T.2 Multan - Haveli 500 kV Stable

Lahore-South 500 kV 30T.3 Lahore-South to Sahiwal 500 kV Stable

Multan 500 kV 30T.4 Multan - Haveli 500 kV Stable

Balloki 500 kV 30T.5 Balloki - Okara 500 kV Stable

Dadu 500 kV 30T.6 Dadu - Shikarpur 500 kV Stable

Matiari 500 kV 30T.7 Matiari - Moro 500 kV Stable

NTDC-Gharo 500 kV 30T.8 NTDC-Gharo - Karachi-E 500 kV Stable

PAEC 500 kV 30T.9 PAEC - Karachi-S 500 kV Stable

Karachi-S 500 kV 30T.10 Karachi-S - Karachi-E 500 kV Stable

NTDC-Jhimpir 500 kV 30T.11 NTDC-Jhimpir - Matiari 500 kV Stable

Jamshoro 500 kV 30T.12 Jamshoro - Dadu 500 kV Stable

IMP-Coal 500 kV 30T.13 IMP-Coal - NKI 500 kV Stable

AES-Coal 500 kV 30T.14 AES-Coal - NKI 500 kV Stable

HUB 500 kV 30T.15 HUB - NKI 500 kV Stable

Tharcoal 500 kV 30T.16 Tharcoal - Matiari 500 kV Stable

Tharcoal 500 kV 30T.17 Trip Tharcoal - KDA 500 kV Stable

Tharcoal 500 kV 30T.18 Tharcoal to Matiari 500 kV Stable



11.3 General Conclusions of Stability Studies

Following are the general findings and recommendations to improve stability of the system;

• There are no problems of angular stability in the system. All the transients damp

down within 2-3 seconds after the clearance of faults in almost all the simulations.

There is good damping torque in the system.

• Power System Stabilizers (PSS) should be installed with all the generating units in

the system

• Detailed studies to work out the dynamic reactive power compensation with loads

modeled as dynamic loads should be performed as a separate exercise. This would

optimize the size and locations of any SVC, FACTS devices if required in the system

due to voltage collapse.

12 COST ESTIMATE OF TRANSMISSION EXPANSION

12.1 Total requirement (BOQs) between 2017 and 2030

The following Table shows the total additional reinforcements required for NTDC network till

the year 2030 over and above the ongoing, committed and planned till 2016-17:

Items Between 2017-2020

Between 2021-2030

220 kV D/C lines (kM) 270 2,623

500 kV D/C Lines (kM) 5394 6700

220/132 kV transformers/substations (MVA) 19,850 79,600

500/220 kV transformers/substations (MVA) 25,800 68,150

± 500 kV HVDC Bipole Converters (MW) 2x(1x1000) -

±500kV HVDC Bipole Transmission line (kM) 654 -

± 600 kV HVDC Bipole Converters (MW) 2x (2x4,000) 6x(2x4,000)

±600kV HVDC Bipole Transmission line (kM) 2000 5770



12.2 Total Cost

The following Table indicates the total investments required till 2030.

Item* Million PKR Million USD**

Projects already committed/Planned to be completed by 2016-17 but not yet funded 428,000 5,350

Projects proposed from 2017 to 2020 569,440 7,118

Projects proposed from 2021 to 2030 1,163,360 14,542

Total 2,160,800 27,010 *Cost for lines crossing international boundaries only include Pakistan component ** USD 1.0 = PKR 80.0

13 CONCLUSIONS & RECOMMENDATIONS

• Transmission Expansion Plan for NTDC system of 500 kV and 220 kV has been

evolved through extensive load capacity analysis and load flow analysis in three

stages and the consolidated schedule of expansion is attached in Appendix-10 as

follows:

o Appendix-10.1: Year by year expansion from 2016-17 to 2020-21



• The expansion plan has progressively assumed to adopt higher ratings of equipment

as follows:

o 500/220 kV transformers to be 750 MVA in general and 1000 MVA for grid

stations in big load centres such as Lahore, Karachi and Faisalabad.

o 220/132 kV transformers to be 250 MVA in general and 350 MVA for grid

stations in big load centres such as Lahore, Karachi, Islamabad, Peshawar,

Faiselabad and Multan.

o 500 kV lines to be double circuit quad bundled using Martin conductor

(ACSR) in North and mid country; and Araucaria (AAAC) in South.



o The space in the existing 500/220 kV and 220/132 kV grid stations should be

utilized for conversion, augmentation and/or extension to enhance their

capacity to have at least four transformers each of 500/220 kV and

220/132kV depending on the availability of space

o Reconductoring or replacement of all existing 220 kV lines of single conductor

to twin-bundled Rail or Greeley conductors

o 220/132 kV grid stations have been proposed in thickly populated areas of

big load centres through:

GIS grid stations of 220/132 kV

Underground cables (XLPE) of 220 kV to interconnect these grid

stations with the main NTDC grid.

• Short circuit analysis has been carried out for the spot years of 2020 and 2030 and

uprating of switchgear has been proposed at existing and future grid stations as

follows:

o 500 kV: short circuit ratings to be 63 kA or 50 kA

o 220 kV: short circuit rating to be 63 kA or 50 kA

o 132 kV: short circuit rating to be 50 kA or 40 kA

• Transient stability study has been performed for the spot years of 2020 and 2030 by

applying the most severe 3-phase permanent fault and final trip of the faulted circuit.

It is recommended to have;

o Power System Stabilizers (PSS) to be installed at all the existing and future

new power plants

o Dynamic System Monitors (DSM) to be installed at all the 500/220 kV grid

stations for real time recording of voltage, currents, frequency etc. to be used

for post-mortem analysis and for tuning of dynamic data of generators and

dynamic loads in the system

• The upcoming problem in the NTDC longitudinal problem having sources of

generation in the far North or far South and load concentrated in mid-country, would

be the deficiency of reactive power (VAR) supply for the load centres. To overcome

this problem the following assumptions were made:



o Switched shunt capacitor banks at all levels 11 kV, 132 kV and 220 kV if

necessary. However the bottom line should be to provide reactive power

compensation as close to the load as possible.

o Dynamic reactive power compensation devices such as SVCs, SVS and other

FACTS controllers. The present plan has quantified the requirement and

locations in terms of switched shunt capacitor banks, which can be

categorized in terms of SVC, SVS and/or FACTS through a detailed voltage

stability study

• Detailed voltage stability study is required to be carried out for the entire NTDC

system using carefully selected composite load model comprising mix of dynamic

and static loads, to optimally quantify and locate the dynamic reactive power

compensation to overcome slow recovery of voltage after fault clearance, a

phenomena common in the system where air-conditioning load is significantly

increasing which is now commonplace in Pakistan.

• It is recommended that complimentary studies considering HVDC faults are

undertaken with both single pole and bipole outages. These studies are intended to

assess the system stability and indicate, if necessary, the requirement to provide

overload capacity on the HVDC lines and converters.

• Capacity building of NTDC Planning engineers for the upcoming challenges and new

devices proposed in the expansion plan, especially SVC, FACTS and HVDC

www.snclavalin.com

SNC-LAVALIN 1801 McGill College Avenue Montreal, Québec Canada H3A 2N4 Tel.: (514) 393-1000 Fax: (514) 334-1446

Issued September 15, 2011

national power system expansion plan

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