SOUTHERN REGIONAL LOAD DESPATCH CENTRE

POWER GRID CORPORATION OF INDIA LIMITED

SPECIAL PROTECTION SCHEMEin

INTRODUCTION LEVEL TRAINING PROGRAMME(POWER SYSTEM)

TO THE OFFICERS OFPOWERGRID G.E.T. 10th BATCH

On

17th June, 2005

by

V.K. AGRAWAL

AGM, SRLDC

SOUTHERN REGIONAL GRID

An Overview

GRID OPERATION AND CONTROL

SPECIAL PROTECTION SCHEME

KHAMMAM

VIJAYAWADANAGARJUNASAGAR

VISAKHAPATNAM

(POWERGRID)HYDERABAD

RAICHUR

GOOTY

HOODY

SALEM

UDUMALPET

TRICHUR

MADURAI

TRICHY

MADRAS

NEYVELI

CUDDAPAHDAVANAGERE

KAIGA

115

317

RSTPP

BHADRAVATI

130x216

4x2

182

151

181

173

302

308172

277

279

155

178x

2

PONDICHERY

BANGALORE

SIRSI

MUNIRABAD

PP

P

P

P

P

P

P

P

P

P

PP

P

P

N

KOLAR

PALLOM

KAYANKULAM EDAMON

TALCHER

JEYPORE

63

187

2x78

2x221

54

HOSUR

KADRA

KODASAALY

Nagjhari

1

120

60

MAPS

P

SSLMM

MMDP

THIRUVANATHAPURAM

ALMATHI

NELLORE

400 KV LINE PRESENTLY

OPERATED AT 220 KV

NELAMANGALA

KURNOOL

GAZUWAKA(AP)

SIMHADRI NTPC

HIRIYUR

189

195

267x

2

258

242

175

179

127

130x

2

221x2

146x252x2

197x2

301x2

8x4

15x2

300

28

330

ABOUT 12000 CKM

400KV TRANSMISSION

TALGUPPA

3500 MW TRANSFER CAPABILITY ON HVDC.ANOTHER 500 MW POLE TO BE ADDED AT GZK. TALCHER POLE CAPABILITY TO BE ENHANCED TO 2500 MW

GRID MAPGRID MAP

TYPICAL FLOWS ARE FROM NORTH TO SOUTH

GRID FOCAL POINT SHIFTED TO KOLAR AFTER COMMISSIONING OF HVDC

QUANTUM CHANGES IN FLOW PATTERN LIKELY AFTER COMMISSIONING OF KOODANKULAM 2000 MW

THE FIRST SCHEME: 1996THE FIRST SCHEME: 1996

KHAMMAM

VIJAYAWADA

NAGARJUNASAGAR

HYDERABAD

RAICHUR

GOOTY

HOODY

SALEM

UDUMALPET

TRICHUR

MADURAI

TRICHY

MADRAS

NEYVELI

CUDDAPAHDAVANAGERE

KAIGA

115

317

RSTPP

BHADRAVATI

130x2

164x

2

182

151

181

173

302

308

172

277

279

155

178x

2BANGALORE

SIRSI

MUNIRABAD

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

N

JEYPORE

63

187

2x221

54

Kadra

Kodasally

Nagjhari

1

120

60

MAPS

P

NELLORE

By Tripping of Salem-Bangalore and

Cudddapah-Madras Southern Grid was

getting devided into two blocks

NELAMANGALA

GAZUWAKA

HIRIYUR

189

267x

2

258

242

175

179

127 130x

2

221x2

146x2

52x2

301x2

300

28

330

FIG-2

THE SR GRID IN

1996

THE FIRST SCHEME: 1996THE FIRST SCHEME: 1996CONDITIONSCONDITIONS

Line Name Frequency Below (Hz)

POWER FLOW(MW)

Time delay (second)

Type of Relay

CUDAPPA-MADRAS 47.8 0.5 UF

SALEM- BANGALORE

47.8 1 UF

CUDAPPA-MADRAS 48.0 100 MW towards CUDAPPA

0.5 RPUF

SALEM- BANGALORE

48.0 300 MW towards BANGALORE

1 RPUF

GRID OPERATION:GRID OPERATION: A TIGHT ROPE WALK A TIGHT ROPE WALK

BLACK-OUTVOLTAGE

COLLAPSE IN-ECONOMIC

OPERATION

INSTABILITYPOWER

SWINGSINCREASED

LOSSES

SPECIAL PROTECTION SPECIAL PROTECTION SCHEMESSCHEMES

DEFINITIONDEFINITIONPROTECTION SCHEME DESIGNED PROTECTION SCHEME DESIGNED

TOTO

DETECT ABNORMAL SYSTEM DETECT ABNORMAL SYSTEM CONDITIONSCONDITIONS AND TAKE AND TAKE

PREDETERMINED CORRECTIVE ACTIONPREDETERMINED CORRECTIVE ACTION

(Other than isolation of faulty element)(Other than isolation of faulty element)

TO TO

PRESERVE SYSTEM INTEGRITY AND PRESERVE SYSTEM INTEGRITY AND PROVIDE ACCEPTABLE SYSTEM PROVIDE ACCEPTABLE SYSTEM

PERFORMANCEPERFORMANCE

TRADITIONAL TRADITIONAL PROTECTION SCHEMES PROTECTION SCHEMES

AND SPSAND SPS TRADITIONAL TRADITIONAL

SCHEMESSCHEMES1.1. PROTECTS PROTECTS

INDIVIDUAL INDIVIDUAL ELEMENTSELEMENTS

2.2. STANDARDISEDSTANDARDISED3.3. MANUFACTURER MANUFACTURER

DRIVENDRIVEN4.4. NARROW ‘VISION’NARROW ‘VISION’

LIMITED TO THE LIMITED TO THE FAULTY ELEMENTFAULTY ELEMENT

MAY DEGRADE SYSTEM MAY DEGRADE SYSTEM CONDITIONS FURTHERCONDITIONS FURTHER

SPSSPS1.1. DESIGNED TO DETECT DESIGNED TO DETECT

SYSTEM DEFICIENCIES SYSTEM DEFICIENCIES AND TAKE CORRECTIVE AND TAKE CORRECTIVE ACTIONACTION

2.2. EVOLVED BY EVOLVED BY EXPERIENCEEXPERIENCE

3.3. UNIQUEUNIQUE4.4. HOLISTIC APPROACHHOLISTIC APPROACH

PRE-EMPTIVE IN NATUREPRE-EMPTIVE IN NATURE PREVENTS SYSTEM PREVENTS SYSTEM

DETERIORATIONDETERIORATION

WHY SPS? WHY SPS? OPERATIONAL OPERATIONAL REASONSREASONS

OUTAGE OF HIGH CAPACITY GENERATING OUTAGE OF HIGH CAPACITY GENERATING UNITS,HVDC INTERCONNECTION OF UNITS,HVDC INTERCONNECTION OF LARGE TRANSFER CAPABILITYLARGE TRANSFER CAPABILITY

WIDE SEASONAL FLUCTUATION IN WIDE SEASONAL FLUCTUATION IN LOADING PATTERNLOADING PATTERN

STAGGERING AND ROSTERING OF LOADS STAGGERING AND ROSTERING OF LOADS

SUDDEN IMPACT ON LARGE GRIDS DUE SUDDEN IMPACT ON LARGE GRIDS DUE TO SYATEM DYANAMICS AND SWINGS.TO SYATEM DYANAMICS AND SWINGS.

WHY SPS? WHY SPS? COMMERCIAL COMMERCIAL REASONSREASONS

SKEWED GENERATION AND LOAD SKEWED GENERATION AND LOAD PATTERN AND PRESSURE ON PATTERN AND PRESSURE ON RELIABILITY MARGINS DUE TORELIABILITY MARGINS DUE TO DRIVEN BY COMMERCIAL MECHANISMS DRIVEN BY COMMERCIAL MECHANISMS

OPEN ACCESS INCREASE IN TRADE OPEN ACCESS INCREASE IN TRADE VOLUMEVOLUME

INCREASE IN COMPETITIONINCREASE IN COMPETITION

MERIT ORDER OPERATIONMERIT ORDER OPERATION

WHY SPS? WHY SPS? PLANNING PLANNING ISSUESISSUES ECONOMY OF SCALEECONOMY OF SCALE

THE SYSTEM PLANNERS TEND TO UTILIZE THE SYSTEM PLANNERS TEND TO UTILIZE THE EXISTING NETWORKTHE EXISTING NETWORK

DELAYS IN NETWORK EXPANSION DUE TO DELAYS IN NETWORK EXPANSION DUE TO ENVIRONMENTAL PROBLEMS ENVIRONMENTAL PROBLEMS

SEASONAL OVER LOADSSEASONAL OVER LOADS

LINES AND GENERATORS NOT COMING IN LINES AND GENERATORS NOT COMING IN TANDEMTANDEM

WHY SPS?WHY SPS?

Mission of power system engineers is to Mission of power system engineers is to provide Stable Secured and Reliable power provide Stable Secured and Reliable power supply at least possible cost to the end supply at least possible cost to the end consumer. SPS is an important tool in consumer. SPS is an important tool in achieving thisachieving this For System Planner It reduce the compromise For System Planner It reduce the compromise

between between cost and qualitycost and quality

For operational planner It enables to manage For operational planner It enables to manage severe severe contingencies like contingencies like

tripping of tripping of generators multiple generators multiple outage of outage of transmission lines transmission lines etcetc

POSSIBLE SYSTEM POSSIBLE SYSTEM PROLEMSPROLEMS

UNIT FAILURE

INSUFFICIENTGENERATION

TRANSFORMER/LINE FAILURE

LOSS OFLOAD

REDUCEDNETWORK

REDUNDANCY

LINE OVERLOADOR

UNSATISFACTORYBUS VOLTAGE

BUS ISOLATED

LOSS OFGENERATION

ISLANDING

SYSTEM SYSTEM COLLAPSCOLLAPS

EE

RESTORATIVE

NORMAL

A L E R T

EMERGENCYDISTURBANCE

RESTORATIVE

NORMAL

A L E R T

EMERGENCYDISTURBANCE

HIGH SPEED INTER-TRIP HIGH SPEED INTER-TRIP SCHEME AT KOLARSCHEME AT KOLAR

GOOTY

HOODY

SALEM

TRICHUR

MADURAI

TRICHY

SPBDR

NLC II

CUDDAPAH

PONDICHERY

SOMANHALLIKOLAR

HOSUR

NLC -1 EXP.

UDUMALPET

BAHOOR

KURNOOL

SOMYAZULA PALLI

TO TALCHER

HIGH SPEED INTER-TRIP HIGH SPEED INTER-TRIP SCHEME AT KOLARSCHEME AT KOLAR

GOOTY

HOODY

SALEM

TRICHUR

MADURAI

TRICHY

SPBDR

NLC II

CUDDAPAH

PONDICHERY

SOMANHALLIKOLAR

HOSUR

NLC -1 EXP.KOZIKODE

UDUMALPET

NLC II EXPBAHOOR

KURNOOL

ANANTPUR

KARAIKUDI

THIRUVARUR

INGUR

SOMYAZULA PALLI

TO TALCHER

HIGH SPEED INTER-TRIP HIGH SPEED INTER-TRIP SCHEME AT KOLARSCHEME AT KOLAR

MODE OF OPERATION

POWER LEVEL FOR GENERATING INTERTRIP SIGNAL

MONO POLAR >400 MW AND THE POLE TRIPS

BI-POLAR IF BOTH POLE ARE CARRYING > 800 MW EACH AND ONE POLE TRIPS

BI-POLAR IF POWER FLOW ON EACH > 200 MW AND BOTH POLE TRIP

KAIGA EVACUATION KAIGA EVACUATION PROBLEMPROBLEM

SPS BASED SOLUTIONSPS BASED SOLUTION

KAIGA

440 MW SIRSI

KADRA

150 MW

KODASHALLI

120 MW

GUTTUR

NAGJHERI

855 MW

HUBLI

400 KV LINE OPERATED AT 220 KV

PROBLEM OF OVERLOADING WHEN HIGH GENERATION AT KALI COMPLEX

THESE LINES ARE TRIPPED IF

>600 AMPS FOR 1SEC OR > 900 AMPS FOR 300 MSEC,

PROPOSED SPS AT PROPOSED SPS AT RAICHURRAICHUR

RAICHURN’SAGAR

MUNIRABAD

DAVANGERE

HIRIYUR

NELAMANGALA

HOODY

GOOTY

CUDDAPAH

KOLAR

HVDC LINES

FROM ER

SOMANAHALLYTRIPPING OF THESE LINES INCREASES THE FLOW ON RAICHUR-N’SAGAR LINE

LOAD CENTRE

PROPOSED SPS BASED SOLUTION

RTPS UNITS TO BACK-DOWN BASED ON FLOW ON

RAICHUR-N’SAGAR LINE

INDUSTRY EXPERIENCE WITH INDUSTRY EXPERIENCE WITH SPSSPS

REPORTED SCHEMESREPORTED SCHEMES 111111 FIRST SPS INSTALLEDFIRST SPS INSTALLED IN 1930IN 1930 SCHEMES REPORTED BY GEOGRAPHICAL SCHEMES REPORTED BY GEOGRAPHICAL

REGIONSREGIONSGEOGRAPHICAGEOGRAPHICAL L

REGIONREGION

% OF % OF SCHEMESSCHEMES

GEOGRAPHICAL GEOGRAPHICAL

REGIONREGION% OF % OF SCHEMESSCHEMES

USAUSA 20.7%20.7% EUROPEEUROPE 16.2%16.2%

JAPANJAPAN 20.7%20.7% AUSTRALIAAUSTRALIA 9%9%

CANADACANADA 19.8%19.8% OTHERSOTHERS 13.6%13.6%

SURVEY IS ONLY INDICATIVE

TypeType %% TypeType %%Generation Generation RejectionRejection

21.621.6 Out Of Step RelayOut Of Step Relay 2.72.7

Load RejectionLoad Rejection 10.610.6 Discrete Excitation Discrete Excitation ControlControl

1.81.8

U/F freq Load U/F freq Load SheddingShedding

8.28.2 Dynamic breakingDynamic breaking 1.81.8

System SeparationSystem Separation 6.36.3 Generator RunbackGenerator Runback 1.81.8

Turbine Valve Turbine Valve ControlControl

6.36.3 Var CompensationVar Compensation 1.8%1.8%

Load & Gen Load & Gen RejectionRejection

4.54.5 Combination of Combination of SchemesSchemes

11.711.7

StabilizersStabilizers 4.54.5 OthersOthers 12.612.6

HVDC ControlsHVDC Controls 3.63.6

PERCENTAGE OF MOST PERCENTAGE OF MOST COMMON SPSCOMMON SPS