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ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED PAKISTAN 1

ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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Page 1: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

ENERGY AUDIT APPLICATIONS

BYAmir Sattar

Resident Engineer220kV Grid Station NTDCL WAPDA Town Lahore

NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED PAKISTAN

1

Page 2: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

CONTENTS

1. Introduction.2. Problem statement.3. Preventive maintenance.4. Why we use GIS.5. Advantages of GIS over AIS.6. HIS7. Comparison of GIS and HIS.

1. Comparison of life cycle cost.2. Cost effectiveness.3. Low investment cost.4. Robust and maintenance free5. Reliability.

8. Configuration of HIS.9. Results and solutions.

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Page 3: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

• National Transmission & Despatch Company(NTDC) Limited was incorporated on 6thNovember, 1998 and commenced commercialoperation on 24th December, 1998. It wasorganized to take over all the properties, rightsand assets obligations and liabilities of 220 KVand 500KV Grid Stations and TransmissionLines/Network owned by Pakistan Water andPower Development Authority (WAPDA).

Page 4: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

NTDCL operates and maintains

12 Nos. 500 KV Grid stations

29 Nos. 220 KV Grid Stations.

5077 km of 500 KV transmission line.

7359 km of 220 KV transmission line inPakistan.

Page 5: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

500 & 220kV NTDC Grid Map

Page 6: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

• SUBSTATIONS

• A place where many circuits are connected together.

• Connecting link b/w transmission & distribution system.

• Assembly of switchgear to direct the flow of energy andensure security of the system.

• Directly control the flow of power into the system.

• Convert the voltage of the supply to a higher or lower level.

• Consists of a number of incoming and outgoing circuitsconnected to a common bus bar system.

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Page 7: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

• 132/11.5kV Grid Station WAPDA Town wasestablished in 1985.

• NTDC constructed new 220kV Grid Station (GIS )alongwith 220kV Transmission line in / out from500/220/132kV Shiekhupura Grid station to220/132/11kV New KotLakhpat Grid Station that isabout 7.5km to north.

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Page 8: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Single Line Diagram 220/132kV Grid Station WAPDA Town

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Page 9: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

9

General Layout Map

Page 10: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

10

Location Map

Page 11: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction• NTDC established new 220kV GIS WAPDA Town Grid

station Lahore in 2010 and having 480MVA PowerCapacity.

• This project was funded by ADB and commenced onJuly 1, 2008. The Grid Station was energized on 28 June2010 on no load and July 06, 2011 on load.

• The estimated cost US$ 36.77 million.

Page 12: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

• New 220kV GIS Portion• 4 Nos. 220kV Transmission Line Bays (2Nos. For

Future).

• 3 Nos. 220/132kV Autotransformer Bays.

• 1 No. 220kV Bus Coupler

• 2 Nos. 220kV P.T’s Bay

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Page 13: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

13

New 220kV GIS Building

Page 14: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

14

New 220kV GIS

Page 15: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

15

New 220/132kV, 160MVA A/TF

Page 16: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

16

New 132kV Transformer Bays

Page 17: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

17

New 220kV Control Room Building

Page 18: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

• 132kV AIS Portion (Old)• 132kV AIS and 11kV portion handover to NTDC from DISCO LESCO

on July 14, 2011.

• 03 Nos. 132/11.5kV Power Transformers.– 2 Nos. 132/11.5KV, 20/26MVA Power Transformer.

– 1 No. 132/11.5KV, 31.5/40MVA Power Transformer.

• 3 Nos. 132/11.5KV, Transformer Bays.

• 06 Nos. 132kV Transmission Line / Circuits(out going).

• 02 Nos. 132kV Transmission Line / Circuits (incoming generationfrom Japan Power Plant).

• 01 No. 132kV Bus Coupler

• 02 Nos. 132kV P.T’s Bay

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Page 19: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Introduction

• 11 kV Portion (Old)

• Total 34 Nos. of 11kV Outgoing feeders

• 3 Nos. 0f 11kV Incoming feeders

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Page 20: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Complete Single Line Diagram

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Page 21: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Why new 220kV GIS Grid Station constructed

• Load growth increase.

• DISCO LESCO load center is supplied by 220/132kVTransformer installed at 220kV Grid station Ravi, NewKot Lakhpat and Bund Road.

• Existing transformer capacity will be exceeded bypeak load conditions in the summer season 2012.

• Over loaded 132kV Transmission Line.

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Page 22: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Why Need For New 220kV Grid Station WAPDA Town

SYSTEM SCENARIO Name of Grid Station

220/132kV Transformer Loading

Without WAPDA Town 220kV

With WAPDA Town 220kV

Peak load August & September 2010

Bund Road 91% 79%

New Kot Lakhpat 86% 71%

Ravi 93% 85%

WAPDA Town - 66%

Peak load August & September 2012

Bund Road 106% 92%

New Kot Lakhpat 99% 80%

Ravi 95% 87%

WAPDA Town - 92%

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Page 23: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Why Need For New 220kV Grid Station WAPDA Town

• Over loaded 132kV Transmission Line

23

System Scenarios

Name of 132kV

Transmission line

Without WAPDA Town

220kV

With WAPDA Town 220kv

Peak load August &

September 2012

KSK-Ravi D/C 81% 75%

Ravi-fort 103% 91%

Page 24: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Why Need For New 220kV Grid Station WAPDA Town

• Due to system reinforcement, Reduction in losses

24

Reduction in system losses

Peak load August & September 2010

Peak load August & September 2012

0.32MW 1.36MW

Page 25: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Existing Problems

– Low short Circuit Current level of all 132kV main equipment installed in AIS Switch yard.

– 132kV Bus Bar is Single Conductor instead of the Twin Conductor.

– Over loaded 132/11.5kV Power Transformers due to increase in load demand.

• Majority of the 132kV main equipment installed has

completed its rated number of operations.

• Red Hot due to excess load.

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Page 26: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Existing Problems

– VCB of 11kV outgoing Panel have completed their rated no. of operations due to excessive load shedding.

– Environmental constraints due to Quaid-e-Azam Industrial Drain in the vicinity of the Grid station. (along the boundary wall of the grid station)• Corrosion of earthing.

• Rusting and Corroding of Steel Structures Due to the presence of high level of H2S gas.

– 132kV Isolator Arms Melting due to under short circuit level.

– High Electrical Stresses due to under short circuit level equipment.

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Page 27: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Existing Problems

• Over loaded power cables of 11kV Outgoing feeders.

• CT’s damaged due to over load 11kV OutgoingFeeders.

• Old 132kV and 11kV relays.

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Page 28: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• ELECTRICAL power is a critically important component affectingproductivity, standard of living, prosperity and strength of anynation. Hence the requirement of electrical power hasincreased manifolds, but the power generation capacity has notbeen able to cope up with the demand creating

an acute electrical power shortage.

• Preventive maintenance carried out regularly in order to ensurethe reliability and smooth operation of the system.

• All equipment are checked by performing standard tests accordingto SOP.

• The system remains in healthy position and faults are avoided.

• Energy saved and losses reduced by carrying out propermaintenance work in the grid station wherever required.

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Page 29: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Replaced 1 set of 132kV, 20kA Circuit Breaker with new 1

set of 132kV, 40kA Circuit Breaker of 132kV WTN-Bund

Road Circuit.

• Replaced 1 set of 132kV, 20kA Circuit Breaker with new 1

set of 132kV, 40kA Circuit Breaker of 132kV WTN-AWT

Circuit.

• Replaced 1 set of 132kV, 20kA Line Isolator with new 1 set

of 132kV, 40kA Line Isolator of 132kV WTN-AWT Circuit.

• Replaced 2 sets of 132kV, 20kA Bus Isolators with new 2 sets

of 132kV, 40kA bus isolators of 132kV Bus Coupler

Page 30: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Replaced 132kV 20kA CT with new 132kV, 40kA CT of132kV Bus Coupler.

• Replacement of 4/0 AWG with 500mcm and 1000 mcm powerCables for 11kV outgoing Feeders.

• CT Ratio change of overloaded 11kV Outgoing feeders.

• Refilling of SF6 gas in 132kV CBs.

• Replacement of deteriorated hawthorn conductor for 132kVmain equipment.

• Replacement of Two Nos. Battery Sets

➢ 110V DC Set A

➢ 220V DC Set B

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Page 31: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Cleaning of the station batteries.

• Checking of electrolyte level in cells.

• Checking of the specific gravity.

• Check the voltage of each cell.

• Cleaning of the cell terminals.

• Check the oil level of the 132kV CTs.

• Current ratio test of 132kV CTs.

• Performed the insulation test of 132kV CTs.

• Check Secondary wiring for measurement.

• Check the secondary terminal connections.

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Page 32: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Tap changer of 132/11.5KV, 20/26MVA Power Transformer, T-

4 has been over hauled for improving system reliability.

• More than 200 Nos. 132kV deteriorated connectors havebeen replaced with new ones in the 132kV AIS SwitchYard sofar by availing Shut Downs whenever possible.

• Most of the equipment installed in the 132kV AIS Switchyard

was corroded. Rust has been removed and efforts have been

made to keep the system neat and clean.

• Cleaning of grass in the switchyard.

• Cleaning of 11kV Bus Bars.

• Vermin Proofing of Transformer Bucholtz Relays.

32

Page 33: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• All 132kV Steel Supporting structures accessories and base frame

of the main equipment have been painted to avoid rusting and

corrosion.

• All the foundations of 132kV as well as 220kV have been bitumen

proofed to remove moisture content and avoid its contact with the

steel structure.

• Phase marking has been completed which helps in clear

identification of the circuit in case of any fault.

• Replacement of Silica Gel for healthy breathing of transformers.

• Environmental study was carried out at the grid station todetermine the environmental constraints affecting the life ofequipment.

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Page 34: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Testing of the contact resistance and opening closing time test of circuit C&DF Tests of Transformers.

• Dielectric Strength Test of Transformer Oil.

• Replacement of deteriorated male female finger contacts of isolators.

• Hydraulic oil checking of 220kV CBs.

• Replacement of damaged distribution box.

• Replacement of the deteriorated/damaged control cables.

• Megger and TTR Tests are performed on Transformers.

• Checking the air pressure of the CBs regularly.

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Page 35: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Replacement of O ring Seals for closing valve of the 132kVTransformer.

• Replacement of bridge rectifier in 11kV Panels for charging of thedc motor.

• Laying of gravel in the 132kV switchyard upto mark.

• Proper earthing of all 132kV main equipment to avoid any mishap.

• Secondary terminal box: cover, cover locks, cover packing, cleaning,proper glands at wiring cable entrance, wiring cable numbering,ground connections etc.

• Check the doors, door locks, light, cleaning, proper glands at wiringcable entrance, vermin proofing, ground connections etc.

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Page 36: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Check the space heater and thermostat settings for intact and operatively of MKs.

• Visual inspection from ground level and keeping in view the same limits of approach to live and moving parts to check apparent condition, abnormal noise, rust on body of the equipment and component parts for 132kV PT’s.

• Check the oil level for 132kV PT’s.

• Check the HV terminal connection (line) for 132kV PT’s.

• Check the porcelain bushing condition for 132kV PT’s.

• Check the ground connection for 132kV PT’s.

• Voltage ratio and insulation resistance test for 132kV PT’s.

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Page 37: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Visual inspection from ground level and keeping in view the same limits of approach to live and moving parts to check apparent condition, abnormal noise, rust on body of the equipment and component parts, position of opening and closing for 132kV CB’s.

• Check SF6 Gas pressure for 132kV CB’s.

• Check air pressure for 132kV CB’s.

• Check steel structure ground connections for 132kV CB’s.

• Check porcelain bushing for 132kV CB’s.

• Check HV Terminal connection for 132kV CB’s.

• Check space heater and thermostat settings for 132kV CB’s.

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Page 38: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Check control switches, key switches, indications, accessories etc for 132kV CBs.

• Check wiring and terminal blocks for 132kV CBs.

• Check rated air pressure for 132kV CBs.

• Check remote and local test operations of 132kV CBs.

• Performed oil DES test for 132kV CBs.

• Performed Contact Resistance for 132kV CBs.

• Check low pressure alarm and lockout pressure of SF6 gas for 132kV CBs.

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Page 39: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Contact alignment (close/open) for 132kV isolators.

• Contact grip / pressure (close/open) for 132kV isolators.

• HV Terminal / connector bearing condition and lubrication for132kV isolators.

• Porcelain insulator base bearing condition and lubrication for 132kVisolators.

• Check the Oil level and oil leakage of conservator main tank andconservator OLTC of transformers.

• Check oil level of bushings of transformers.

• Check Cooling system of transformers.

• Check oil and winding temperature guages of transformers.

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Page 40: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Ground connection of the neutral terminal of transformers.

• Ground connection of tertiary winding terminal oftransformers.

• Check HV , LV Bushing condition and terminal connections oftransformers.

• Clamping / supports for the radiator tubes fixture oftransformers.

• Check the radiator tube valves of transformers.

• Pressure relief device of transformers.

• Check the buccholz relays of transformers.

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Page 41: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Visual inspection from ground level and keeping in view the same limits of approach to live and moving parts to check apparent condition, abnormal noise, rust on body of the equipment and component parts, position of opening and closing of GIS.

• Test operation of ventillation fans from control at each entrance door of GIS Hall.

• Check the SF6 gas pressure of GIS.

• Check the steel structure ground connections of GIS.

• Check the HV in and out terminal connections (SF6 To Air Bushing) of GIS.

• Supporting structures nuts/ bolts/ level of GIS.

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Page 42: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Alignment check of disconnecting switches/isolators of GIS.

• Visual check of CB contacts through Inspection Glass Hole of GIS.

• Check CTs Secondary Terminal box: cover, cover locks, cover packing, cleaning, proper glands, wiring cable numbering , venim proofing, ground connection etc.

• Check PTs Secondary Terminal box: cover, cover locks, cover packing, cleaning, proper glands, wiring cable numbering , venim proofing, ground connection etc.

• Check the doors, door locks, light, cleaning, proper glands at wiring cable entrance, vermin proofing, ground connections etc.

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Page 43: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE CARRIED OUT

• Control switches, key switches, indication accessories etc.

• Space heater and thermostat settings.

• Check Hydraulic oil level of hydraulic oil pressure operating mechanism of GIS 220kV CBs.

• Check hydraulic oil pressure of GIS 220kV CBs.

• Check the oil leakage of GIS 220kV CBs.

• Safety valve function check of GIS 220kV CBs.

• Check hydraulic oil pump: cut in/out pressure valve check.

• Check hydraulic oil pump, accessories of GIS 220kV CBs.

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Page 44: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• DIGITAL RELAYS

• Replaced the old/faulty electro-mechanical relays with new digital relays.

• Programming, Testing, Installation andcommissioning.

• Saved huge revenue loss that was causeddue to undesired tripping of faulty relays.

Page 45: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• Maintained proper indications, controlcircuit for each circuit by working day andnight.

• Fixed wrong wiring problems.

• Maintained healthiness of protectioncircuit / protective relays.

Page 46: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• TESTING OF RELAYS

• Testing of each individual relays accordingto the defined procedures.

• Applied latest testing techniques withmodern testing equipment.

• Proper study and concepts before testing.

• Thorough study of application manuals ofeach individual relay.

Page 47: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Due to memory record of faults, it hasbecome easy to analyze and troubleshootthe faults.

• Decreased downtime due to rapidtroubleshooting and remedial measureswith the help of fault records stored inthe relay.

PREVENTIVE MAINTENANCE

Page 48: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• DISTANCE RELAYS

• Installed new digital distance relays onfollowing circuits

• 132KV WTN-J.P.H Circuit 1&2 (E13Q1&E14Q1)

Siemens Make 7SA522 Digital Distance Relay

• 132KV WTN-BDR Circuit (E7Q1)

ABB Make REL511C1 Digital Distance Relay

Page 49: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• DIFFERENTIAL RELAY

• Installed new digital differential relays on followingcircuits

• 132/11.5KV, 20/26MVA, Power Transformer T4

Siemens Make 7UT612 Digital Differential Relay

• 132/11.5KV, 31.5/40MVA, Power Transformer T5

Siemens Make 7UT612 Digital Differential Relay

Saved huge revenue loss that was causing due tounnecessary trippings due to faulty relays.

Page 50: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• OVER CURRENT RELAYS

• Installed new digital OC/EF relays on following circuits

• 132/11.5KV, 20/26MVA, Power Transformer T4

Areva Make Micom P122 Digital Differential Relay

• 132/11.5KV, 31.5/40MVA, Power Transformer T5

Areva Make Micom P122 Digital Differential Relay

• Saved huge revenue loss that was causing due tounnecessary trippings due to faulty relays.

Page 51: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• Installed new digital OC/EF relays on following circuits

• 132/11.5KV, 20/26MVA, Power Transformer T4, T5 &T6 (11KV Incoming Panel)

ABB Make SPAJ 140C Digital OC/EF Relay

11KV Outgoing Panels

3No. 11kv Outgoing Feeders

132KV WTN-J.P.H CCT-1 & 2

Areva Make Micom P122 OC & EF Relay

Page 52: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• DISTANCE RELAYS

• Installed new digital distance relays onfollowing circuits

132KV WTN-J.P.H CCT-1 & 2

iemens Make 7SA522 Digital Distance Relays

New digital distance relays have built-in faultlocator which shows the distance in KM or Milesfrom grid station during a fault on the line.

In this way, the approximate tower no. can betraced and fault can be removed within minimumpossible time.

Page 53: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• CONTROL CABLES

• Replaced old faulty control cables which were causingun-necessary trippings of 132/11.5KV PowerTransformers T4 & T5.

• During rain, due to filling of water inside the trenches,tripping pulse was generated from points where thecontrol cables were damaged.

• Saved huge revenue loss that was caused due to faultycontrol cables.

Page 54: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

INDICATION BLOCKS

Installed new indication blocks on control panels of 132KVCircuits for replacement of faulty ones.

Indication blocks show the tripping of CB, Relays, alarmsrelated to CB etc.

Alarms alert the operator to take required action in orderto avoid un-necessary tripping of the circuit.

Page 55: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

PREVENTIVE MAINTENANCE

• For example SF6 GAS Low Alarm, Spring Discharged,mechanism faulty etc. helps the operator to takenecessary action in order to avoid damage to theequipment if CB fails to trip.

• Due to installation of new indication blocks, faults areacknowledged as soon as they appear.

Page 56: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Less space requirements, especially in congested city

areas, saving on land costs and civil works.

• Low visibility buildings can be designed to blend in with

local surroundings.

• Less sensitivity to pollution, as well as salt, sand or even

large amounts of snow.

• Increased availability and reduced maintenance costs.

WHY WE USE GIS

Page 57: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Higher personnel safety due to enclosed high voltage

equipment and insignificant electromagnetic (EM) fields

• GIS variant is more costly than the AIS solution.The

capability to install a GIS substation within a

significantly smaller site – typically up to 80 per cent

smaller - enables it to be located close to the load

centres, providing a far more efficient network structure

at both the HV (high voltage) and MV (medium voltage)

levels. As a result, both the investment and operating

costs are reduced.

ADVANTAGES OF GIS OVER AIS

Page 58: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• GIS is also the more economic alternative when

expanding or replacing existing substations. An inner

city site that has been used previously for an AIS

installation could be sold or rented out and the income

used to finance the new substation. The compact nature

of GIS enables an HV transformer substation to be fully

integrated in an existing building, which may only have

to be increased in height or have a basement added.

ADVANTAGES OF GIS OVER AIS

Page 59: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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OtherSolutions

HIS

COMPARISON OF GIS AND HIS

Page 60: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

HIS

• Due to improve physical security and availability of substationare increasing interest in todays deregulated energy market.New switchgear concept like mixed technology switchgear,compact substation solution, modular substation, using AIS orGIS or any combination of it can be used to improve physicalsecurity and availability of the substation.

• Based on the AIS and GIS technology compact solution likehighly integrated switchgear (HIS) were developed to combinethe advantage of the gas insulated metal enclosed switchgearwith air insulated elements.

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Page 61: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Site Price

• Investment Costs

– Civil works

– Secondary cables

– Supporting

– Earthing

– High voltage equipment

– Erection, tests, commissioning

• Reliability, Availability, Inspection, Maintenance

– Retrofit

– Reconstruction of concrete foundations

– Painting

– Inspections

– Visual inspections

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COMPARISON OF LIFE CYCLE COST

Page 62: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Standardized modules enable implementation of allcommonly-used layouts

• Control and protection schemes ranging fromconventional to digital or process-bus based

• Low life-cycle-costs

– Low operating costs

– Minimal maintenance

– Long service life

• Spare parts available from current production within 24h

• Replacement of complete bays possible at short notice

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COST EFFECTIVENESS

Page 63: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Short planning and delivery times• Factory pre-assembled and tested units• Simple construction, few foundations required• Short realisation time• Small space requirement• Extensions of existing switchgear possible at all times,

even during operation• Environment-friendly• Consideration of resources

– Material– Manufacturing process– Energy consumption during manufacturing– Recyclable

• Space requirement less than GIS

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LOW INVESTMENT COST

Page 64: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Operating life > 50 years

• Major inspection: not before 25 years

• Minimal cleaning requirement

• Corrosion-resistant

• Motor-operated self-lubricated mechanisms

• Low fault-probability / high availability

• Protected from aggressive environmental conditions

• A seismic

• Impervious to wind and ice

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ROBUST AND MAINTENANCE FREE

Page 65: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

• Safe to touch due to earthed enclosure

• Risk-free isolation and earthling

• Minimal number of outdoor insulators

• Protected from external influences

• Layout clearly arranged in one level

HIS take the advantages of the GIS technology into the

outdoor

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RELIABLE AND SAFE

Page 66: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

GAS INSULATED SWITCHGEAR SAVING HIGHLY INTERGRATED

SWITCHGEAR

Angular modules are used with 30,

45, 60, 90 Degree

In horizontal arrangement there is

no longer a need for any type of

angular modules

One and half breaker solution

might not be necessary using

today’s GIS technology

Particular advantages with spur

bays, H-schemes with three, four

or five circuit breaker and with air

insulated (flexible) single or

duplicate busbar arrangement

Rigid busbar used in GIS H-configuration with three circuit

breakers, could be assembled and

put into service in one week

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COMPARISON OF GIS AND HIS

Page 67: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Duration of downtime 96 h This allows a quick exchangeability of

circuit breaker, disconnector, and current

modules within 6 hours.

To reduce the repair time the gas-

insulated switchgear part is separated in

modular GIS- section

High reliability and availability of the gas

–insulated part of the substation with

lower cost and high reliability of the air-

insulated busbar

Space required 900 m sq Space required 350 to 360 m sq

Primary equipment 100% Primary cost 90%

Civil works 100% Civil works 30%

Maintenance 100% Maintenance 80%

Site price 100% Site price 60%

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Page 68: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Planning and engineering

100%

Planning and engineering 80%

During running extension possible

No need for the building, robust type

material

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69

already in use by operational

Life tank GIS / Dead tank experience

outdoor/HIS

◼ Temperature: -30° C up to +55° C x x 40 years

◼ Aluminum enclosures (cast metal and Knet) x x 25 years

◼ Outdoor-proof cubicles and operating x x 40 years

mechanism with anti-condensation heater

◼ Built-on accessories (carrier, linkages, sections) x x 40 years

◼ SF6-sealing system (O-ring, shaft gland) x x 40 years

◼ Outdoor bushings x x

Composite or porcelain insulator (40 mm/kV) 10/40 years

◼ Pressure / temperature monitoring x x

Sensors or density monitors with trend indication 25 years

◼ Sealed built-on attachments x x 25 years

◼ Threaded joints x x 40 years

◼ Interrupter unit x x 25 years

◼ Spring-stored-energy mechanism x x 25 years

Page 70: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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Previous

Afterwards

Page 71: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Space required 900 m sq Space required 350 to 360 m sq

Primary equipment 100% Primary cost 90%

Civil works 100% Civil works 30%

Maintenance 100% Maintenance 80%

Site price 100% Site price 60%

Planning and engineering 100% Planning and engineering 80%

Duration of downtime 96 h This allows a quick exchangeability of

circuit breaker, disconnector, and

current modules within 6 hours

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Page 72: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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8000

8000

Line 1 Line 2

HIS SINGLE FEEDER

Page 73: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

737

m /

23

ft

16m / 52 ft

2 m

/ 7

ft

2 m / 7 ft

6,5

m /

20

ft

HIS 3 CB H-ARRANGEMENT

Page 74: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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16 m / 52 ft

12

m /

39

ft

11 m / 36 ft

5 m

/ 1

6 f

t

3,4 m / 11 ft

Line 1 Line 2Line 1 Line 2

Tr. 1 Tr. 2

12

m /

39

ft

5 m

/ 1

6 f

t1

2 m

/ 3

9 f

t5

m /

16

ft

HIS 4 CB H-ARRANGEMENT

Page 75: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

75

16 m / 52 ft

12

m /

39

ft

12,5 m / 40 ft

5 m

/ 1

6 f

t

3,4 m / 11 ft

Line 1 Line 2 Line 1 Line 2

Tr. 1 Tr. 2

HIS 5 CB H-ARRANGEMENT

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76

Busbar 1 Busbar 2

Lin

e 1

8 m / 26 ft 8 m / 26 ft

8 m

/ 2

6 f

t5

m /

16

ft

12 m / 39 ft

Bu

sbar

1

Bu

sbar

2

Line 1

HIS DUPLICATE BUS SYSTEM

Page 77: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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Busbar 1 Busbar 2

8 m / 26 ft 8 m / 26 ft

8 m

/ 2

6 f

t5

m /

16

ft

11 m / 16 ft

Bu

sbar

1

Bu

sbar

2

HIS DUPLCATE BUS SYSTEM

Page 78: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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Busbar 1 Busbar 2

8 m / 26 ft 8 m / 26 ft

11 m / 21 ft

Lin

e 2

Line

1Lin

e 2

Busbar 1

Busbar 2

HIS DUPLICATE BUS SYSTEM

Page 79: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

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TransformerBusbar 1 Busbar 2Line

HIS EXTENSION OF OUTGOING FEEDERS

Page 80: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

RESULTS / CONCLUSION

1. Replacement of all old 132kV AIS Equipment with the GIS or HIS. 2. HIS compact solutions combine space savings, high reliability and

availability of the gas-insulated part of the substation with lower cost and high reliability of the air-insulated busbar.

3. When this is done, it is often the case that the investment costs for HIS substation are about the same as those for Air-Insulated Substations solutions. In addtion, the life cycle costs of HIS solutions are reduced due to lower expenditure on maintenance

4. In GIS-technology much higher down time is needed to repair the switchgear.

5. Compact solution Highly Integrated Switchgear have additional step to improve availability of the substations results in the reduction of repair time for the gas insulated switchgear part.

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Page 81: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

RESULTS / CONCLUSION

5. To reduce the repair time the gas insulated switchgear part is separated in modular GIS-section.

6. This allows a quick exchangeability of circuit breaker, disconnector, or current transformer modules within 6 hours.

7. All moving parts are protected against environmental impact which also increases the security of the switchgear.

8. In installations certain standard configuration like H / T In-out schemes; the strength for extensions.

9. The high quality and the design properties of HIS contribute to: life-cycle benefit, high operating safety, long service life. HIS technology provides, for any kind of substation solution, a good base to reach 24 hours / 7 days availability.

10. Thanks to the direct connection of the circuit breaker, there is no need for large quantities of outdoor bushings or other insulators, nor for the foundations.

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Page 82: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

RESULTS / CONCLUSION

11.With the HIS modules all circuit variants can be implemented on a horizontal plane. Correspondingly, this also means that there is no longer a need for ant type of angular modules. They also offer particular advantages with spur bays, H-scheme with three, four or five breakers and with air-insulated single or duplicated busbar arrangement. All modules fit together at the same height.

12. Low fault-probability, minimal cleaning requirement.13. Extensions of existing switchgear possible at all times, even

during operation.14.Spare parts available from current production within 24 h &

replacement of complete bays possible at short notice.

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Page 83: ENERGY AUDIT APPLICATIONS...ENERGY AUDIT APPLICATIONS BY Amir Sattar Resident Engineer 220kV Grid Station NTDCL WAPDA Town Lahore NATIONAL TRANSMISSION AND DESPATCH COMPANY LIMITED

Thank you

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