special protection schemes

SPECIAL PROTECTION SCHEMES

S.P.KUMAR

CM(SRC&S)

SRLDC, BANGALORE

SPECIAL PROTECTION SCHEMESDEFINITION

PROTECTION SCHEME DESIGNED TO

DETECT ABNORMAL SYSTEM CONDITIONS AND TAKE

PREDETERMINED CORRECTIVE ACTION (Other than isolation of faulty element)

TO PRESERVE SYSTEM INTEGRITY AND

PROVIDE ACCEPTABLE SYSTEM PERFORMANCE

WHAT IS SPS?According to P.M.Anderson SPS is defined as “ a

protection scheme that is designed to detect a particular system condition that is known to cause unusual stress to the power system and to take some type of predetermined action to counteract the observed condition in a controlled manner. In some cases, SPSs are designed to detect a system condition that is known to cause instability, overload, or voltage collapse. The action prescribed may require the opening of one or more lines, tripping of generators, ramping of HVDC power transfers, intentional shedding of load, or other measures that will alleviate the problem of concern.”

Security Monitoring

Preventive Control

Emergency Control

Normal

Restorative

In extremis

Restoration

Alert

Emergency

SECURITY WEAKENED. INCLEMENT WEATHER.

ALL CONSTRAINTS ARE MET.

SECURITY MONITORING TOOLS KICK IN. RRPA IS SUGGESTED TO BRING SYSTEM BACK TO NORMAL..LIKE GENERATION SHIFTING ETC

RELIABILITY CRITERIA NOT MET. VOLTAGE AT BUSES MAY BE UNACCEPTABLY LOW. ELEMENT LOADING MAY EXCEED LIMITS.

EMERGENCY CONTROL ACTIONS- FAULT CLEARING, EXCITATION CONTROL, LOAD SHED, GENERATION RUNBACK, HVDC MODULATION

CASCADING OUTAGES, ISLANDING, MAJOR PARTS OF GRID ARE BLACKED OUT

STABILITY

• ‘Power system stability is the ability of an electric power system, for a given initial operating condition, to regain a state of operating equilibrium after being subjected to a physical disturbance, with most system variables bounded so that practically the entire system remains intact.’

Source:-P.M.Andersen

STABILITY IN POWER SYSTEMS

FAST ACTING: WAMS BASED SPS

UFR, DF/DT DV/DT ,under VoltageRELAYS

GENERATION OR LOAD SHEDDING

COMBINATION OF CONVENTIONAL RELAYS AND BROADBAND COMMUNICATION

Source:-VLPGO WG

WHY SPS? OPERATIONAL REASONS

• OUTAGE OF HIGH CAPACITY GENERATING UNITS,HVDC INTERCONNECTION OF LARGE CAPACITY

• WIDE SEASONAL FLUCTUATION IN LOADING PATTERN

• STAGGERING AND ROSTERING OF LOADS CAUSING UNPRECEDENTED SKEWING

• SUDDEN IMPACT ON LARGE GRIDS DUE TO SYsTEM DYANAMICS AND SWINGS.

WHY SPS? COMMERCIAL REASONS

• SKEWED GENERATION AND LOAD PATTERN AND PRESSURE ON RELIABILITY MARGINS DUE TO– COMMERCIAL MECHANISMS

– OPEN ACCESS INCREASE IN TRADE VOLUME

– INCREASE IN COMPETITION

– UNBUNDLING AND RESTRUCTURING

WHY SPS? PLANNING ISSUES• ECONOMY OF SCALE, LARGE PITHEAD PLANTS

AND LONG TRANSMISSION LINES

• THE SYSTEM PLANNERS TEND TO UTILIZE THE EXISTING NETWORK

• DELAYS IN NETWORK EXPANSION DUE TO ENVIRONMENTAL PROBLEMS

• SEASONAL OVER LOADS

• LINES AND GENERATORS NOT COMING IN TANDEM

• EVACUATION OF RENEWABLES BY DEROGATING RELIABILITY CRITERIA

AN EXAMPLE OF A BASIC SPS

INFINITE GRID

LOADS

2000 MW

GENERATOR

CONVERTER

INVERTER

HIGH CAPACITY

DC LINK

TYPICAL FLOW OF 1800-2000 MW

THIS NETWORK IS UNABLE TO EVACUATE MORE THAN 500 MW

SPS ACTION WOULD BE TO TRIP THE GENERATORS IN STAGES TO LIMIT FLOW ON A-B SECTION.

IF SPS WERE NOT THERE THE GENERATOR WOULD BE CONSTRAINED OR A-B SECTION WOULD NECESSARILY HAVE TO BE STRENGTHENED

INCREASED TRANSFER CAPABILITY

DEFFERED INVESTMENT

TRADITIONAL PROTECTION SCHEMES AND SPS

• TRADITIONAL SCHEMES

1. PROTECTS INDIVIDUAL ELEMENTS

2. STANDARDISED3. MANUFACTURER

DRIVEN4. NARROW ‘VISION’

– LIMITED TO THE FAULTY ELEMENT

– MAY DEGRADE SYSTEM CONDITIONS FURTHER

• SPS1. DESIGNED TO DETECT

SYSTEM DEFICIENCIES AND TAKE CORRECTIVE ACTION

2. EVOLVED BY EXPERIENCE

3. UNIQUE4. HOLISTIC APPROACH

– PRE-EMPTIVE IN NATURE– PREVENTS SYSTEM

DETERIORATION

SPS is used • During rare contingencies

• When focus for the protection is on the power system supply capability rather than on a specific equipment

• When consequences of an operating condition is outside the capability of conventional protection

SPS Characteristics• Are normally sleeping systems

– Operate infrequently• Control actions taken is predetermined• Can be armed or disarmed depending upon

system conditions• Can comprise a large number of coordinated

actions, in a cascaded manner– Under frequency controlled load shedding

in a number of steps at different frequency levels and/or with different time delays

SPS DESIGN• DEFINE THE CRITICAL CONDITION

– STUDY OF PAST DISTURBANCES– LOAD FLOW AND STABILITY STUDIES

• IDENTIFY RECOGNITION TRIGGERS– TRIP RELAYS,– HVDC POLE BLOCK SIGNALS– LOW VOLTAGE– LOW FREQUENCY– DF/DT– COMBINATION

• SUPER TRIGGERS• OPERATOR CONTROL OF SPS

– AUTOMATIC ARMING/DISARMING– MANUAL BASED ON OPERATORS

NOMOGRAMS/INFORMATION

OPERATOR NOMOGRAM FOR ARMING/DISARMING SPS

ΣFLOW ON BOTH CIRCUITS OF TALCHER-ROURKELA

1000 MW

100 MW 800 MW

FLO

W O

N R

AIP

UR

-RO

UR

KE

LA

CR

ITIC

AL

SIT

UA

TIO

N I

N O

TH

ER

P

AR

T O

F G

RID ARM SPS-1000

ARM SPS-450

Advantages of SPS

• Helps in operating power systems closer to their limits

• Increase power transfer limit while maintaining the same level of system security

• Increase the power system security particularly towards extreme contingencies leading to system collapse

TYPICAL SPS ACTIONS

• Generation rejection• Turbine fast valving/generator run-back• Gas turbine/Pumping storage start-up• Under frequency load shedding• Under voltage load shedding• Remote load shedding• HVDC fast power change• Automatic shunt reactor/capacitor switching

TYPICAL SPS ACTIONS

• Controlled disconnection of interconnection/ area islanding

• Tap changer blocking and set point adjustment• Quick increase of generator voltage set point• Dynamic braking or braking resistor• Actions on the AGC such as set point changes

Type % Type %Generation Rejection 21.6 Out Of Step Relay 2.7

Load Rejection 10.6 Discrete Excitation Control 1.8

U/F freq Load Shedding 8.2 Dynamic breaking 1.8

System Separation 6.3 Generator Runback 1.8

Turbine Valve Control 6.3 Var Compensation 1.8%

Load & Gen Rejection 4.5 Combination of Schemes 11.7

Stabilizers 4.5 Others 12.6

HVDC Controls 3.6

PERCENTAGE OF MOST COMMON SPS

INDUSTRY EXPERIENCE WITH SPS• REPORTED SCHEMES 111• FIRST SPS INSTALLED IN 1930• SCHEMES REPORTED BY GEOGRAPHICAL

REGIONSGEOGRAPHICAL

REGION

% OF SCHEMES

GEOGRAPHICAL

REGION

% OF SCHEMES

USA 20.7% EUROPE 16.2%

JAPAN 20.7% AUSTRALIA 9%

CANADA 19.8% OTHERS 13.6%

SURVEY IS ONLY INDICATIVE

Source:-P.M.Andersen

Date/time Description SPS Control Actions Consequences

Jul 6th, 200323h59min

Outage of 3 circuits – 765 kV associated with Itaipu system (atmospheric strokes)

Generation drop (2,940MW) at Itaipú 60Hz maintaining S/SE ties integrity

System stableΔf = - 0.8Hz

Sept 16th, 200303h13min

Outage of 4 circuits - 765 kV connected to Itaberá S/S due to atmospheric strokes and protection against misoperation

Generation drop (1,400 MW) at Itaipu 60Hz, maintaining S/SE ties

System stableΔf = - 0.4Hz

Dec 9th, 200317h39min

Outage of 10 circuits - 440 kV trunk & 2 transformers - 440/138kV at Bauru S/S (busbar short-circuit)

Generation drop at hydro plants on Paranapanema River to control electromechanical system oscillations.

System stableΔf = - 0.9HzNo load shed

Sept 26th, 200405h38min

Clearing of 500 kV busbar at Jaguara S/S - tripping of 4 circuits - 500 kV & 2 transformers - 500/345 kV (short-circuit)

Actuation of SPS avoided overload in system equipment


Jun 14th, 200515h26min

Outages of 2 circuits - 765 kV associated with Itaipu 60 Hz, 9 T Lines towers collapsed (strong winds)

Generation drop at Itaipu 60 Hz (2800MW) avoiding risk of opening remaining circuit


Oct 4th, 200520h40min

Tower collapse of 3 circuits Foz do Iguaçu -Ivaiporã 765 kV, by strong winds, islanding Itaipú (4,800 MW)

Out-of-step protections at the SE/NE and N/SE ties avoiding propagation of disturbance toward N and NE subsystems

System stableΔf = - 1.7Hz6.5% load shedding in S/SE/MW subsystems

Mar 6th, 200515h04min

Accidental actuation of overload protection in the electrodes lines of the Itaipu HVDC link, during maintenance services in Bip. 1, leading to Bip. 2 blocking

Correct actuation of out-of-step protection, avoiding propagation of the disturbanceLoad shedding scheme in S/SE regions

System stableInterruption of 2,700 MW transmitted by HVDC (bipole 2)2,154W load sheddingΔf = - 0.8Hz

Sep 4th, 200515h04min

Loss of two 765 kV circuits connected to Itabera S/S + outage of Bipole 1 (fallen towers by strong winds)

Generation drop ( 2100 MW ) at Itaipu 60 Hz Power Plant

System stableΔf = - 0.7HzHVDC transmission was reduced from 6300 to 3150 MW

EXPERIENCE WITH SPS IN BRAZIL SYSTEM

Source:-Vlpgo wg

SPS SCHEMES IN SR

THE FIRST SCHEME: 1996CONDITIONS

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

THE FIRST SCHEME: 1996CONDITIONS

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

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

SPS’s proposed in SR and its status of implementation

1

SPS @ Kolar Trip Signal 1 & 2 Commissioned

SPS @ Talcher 450/1000 Commissioned

Trip Signal 3 @ Kolar Proposed & Under Implementation.

2 Modification of SPS @ Talcher Intertrip Proposed & Under Implementation.

3 SPS @ KoodankulamProposed & Under commissioning, would

come along with Project

4 Intertrip @ Kali ComplexProposed by PCC Sub-Committee. Under

Implementation

5 Intertrip @ Varahi Proposed by PCC Sub-Committee.

6Intertrip @ Salem for enhancing transfer capability between S1 and S2 bid area

Proposed by SRLDC. Agreed by Constituents.

Under Implementation.

7Post Contingency generation ramp down at

Vemegiri Complex and LANCO for 400kV Vijayawada-Nellore outage

Proposed by SRLDC. Agreed by Constituents

Under Implementation.

8Intertrip @ Madakathara to decongest for one

ICT tripping or one idukki-Lower Periyar-Madakathara trip

Commissioned

9Intertrip @ 220kV Peenya to cut radial loads for

220kV NLM-Peenya line tripping Under implementation

10Intertrip for post contingency tripping of 220kV

Muddanur-ChnnakampallyProposed by SRLDC. Yet to be

implemented

NARENDRA

MAHABOOB NAGAR

CHITTOOR

VIJAYAWADA

GAZUWAKA

GHANAPUR

RAICHUR

GOOTY

SALEM

UDUMALPET

TRICHUR

MADURAI

TRICHY

SRIPERUMBUDUR

NEYVELI

GUTTUR

KAIGA

RSTPP

BHADRAVATI

MUNIRABAD

P

P

P

P

P

KOLAR

TALCHER

JEYPORE

HOSUR

SSLMM

MMDP

TRIVANDRUM

NELLORE

KALPAKKA

SIMHADRI

HIRIYUR

TALGUPPA

KADAPA

NEYVELI TPS – 1 (EXP)

HOODY

KURNOOL

KHAMMAM

N’SAGAR

ALMATHY

MYSORE

NELAMANGALA

SOMANAHALLIKALAVINDAPATTU

TIRUNELVELI

DITCHIPALLY

PUGALUR

GAJWEL

BTPS

WARANGAL

Highly loaded

Medium loaded

Lightly loaded

Typical flow directions in SR

HVDC Kolar SPS

Kolar SPS Logic:Trip signal-1

Kolar SPS Logic:Trip signal-1: Load relief by constituents

Kolar SPS Logic:Trip signal-2

Kolar SPS Logic:Trip signal-2: Load relief by constituents

KOLAR SPECIAL PROTECTION SCHEME

Performance of the SchemeFREQUENCY DIP DURING KOLAR HVDC TRIPING AND DURING SIMHADRI GENERATION LOSS

48.5

48.7

48.9

49.1

49.3

49.5

49.7

49.9

50.1

T-30 Minutes T-25 Minutes T-20 Minutes T-15 Minutes T-10 Minutes T-5 Minutes T=0 Minutes T+5 Minutes

Time

FR

EQ

IN

HZ

TAL-KOL TRIP ON15-09-06 AT 16:52 HRS LOSS IS 1887 MW

SIMHADRI GEN LOSS OF APPROX 950 MW ON 16-01-07

AT 1812 HRS

Frequency Trend during the Tal-Kolar pole 2 trip

0200400600800

100012001400160018002000

0:01

0:03

0:05

0:07

0:09

0:11

0:13

0:15

0:17

0:19

0:21

0:23

0:25

0:27

0:29

Time

Pow

er fl

ow

49.25

49.3

49.35

49.4

49.45

49.5

49.55Talcher-Kolar power flow

Frequency

SPS AT TALCHER END

SPS 450-1000

Talcher SPS Logic:SPS 450:

Talcher SPS Logic:SPS 1000:

PROPOSED MODIFICATION TO SPS AT HVDC KOLAR

PROPOSED MODIFICATION TO SPS AT HVDC KOLAR

• LOGIC FAILS IF POWER GOES DOWN IN STEPS. SIGNAL 2 IS NOT SENT• GRID HOWEVER SEES A LARGER LOSS OF POWER• PROPOSED MODIFICATION: INCREASED WINDOW OF JUDGEMENT, LINE FAULT AS INPUT

Sr.No. EventDate ofOccurrence

Time ofOccurence Reason Remarks

1

Talcher-Kolar Pole-2 Tripped and Pole-1 went to Ground Return

Power Flow:2106 MW to 142 MWFrequency: 49.28 Hz to 48.5 Hz

03.04.2009 12:08

DC Line fault in Pole2, Distance 13.18 km from Talcher end (Tower no. 40)

Signal-1 sent

2



04.04.2009 10:34

DC Line fault in Pole2, Distance 14.5 km from Talcher end (Tower no. 43)

Signal-1 sent

3



10.06.2009 19:17

DC Line Fault in Pole1, Distance 498.1 km from Kolar end(Tower no.2334)

Signal-1 sent

Talcher-Kolar Flow and Frequency on 13/02/2009 during Pole-1 Tripping

0

200

400

600

800

1000

1200

1400

1600

1800

2000

6:20 6:22 6:24 6:26 6:28 6:30 6:32 6:34

TIME

MW

48

48.2

48.4

48.6

48.8

49

49.2

49.4

49.6

49.8

50

Talcher-Kolar MW is at Kolar end

1710 MWat 06:24 Hrs

TAL-KOL FLOW

643 MWat 06:28 Hrs

1252 MWat 06:26 Hrs

380 MWat 06:30 Hrs

49.19 MWat 06:24 Hrs

48.63 MWat 06:27 Hrs

FREQUENCY

Talcher-Kolar SPS Logic Diagram MODIFIED

PERFORMANCE OF THE SPS

• Mal-operation On six occasions the scheme operated when not required to operate due to failure of the HVDC measuring equipments like Optodyne

• Non operation. On Nine occasions defense mechanism failed to operate when required due to following reasons – On four occasions when one of the pole tripped on ground fault inter trip

signal was not generated. The logic was working only on power flow levels and line fault signal was not used. This has been taken care in the Stage –II SPS logic development

– Problem with the logic in 1 case, during the initial stages of the logic development, which was latter corrected.

– In the remaining four cases, three cases non operation was due to the signal input. The power level signals were derived from HVDC control which was changing only in steps therefore decisions were influenced by the power levels in specified steps at times,could not detect the actual loss of power of more than 400MW. This has been taken care in the Stage –II SPS logic development

– Remaining one case due to control supply failure

No. of one Pole / Bipole

trips

No. of times System Protection Scheme

Operated Operated correctly Mal-Operated Failed to operate

69 27 21 6 9

Based on survey in 2003

SPS PLC SCHEMATIC

PROGRAMMABLELOGIC

CONTROLLER

ANALOG INPUT

DIGITAL INPUT

DIGITAL OUTPUT

DIGITAL TELEPROTECTION COUPLER

≈FIBER OPTIC

CABLE

DIGITAL TELEPROTECTION COUPLER

K1 K2 K3 K4

K1 K2 K3 K4

WIRED TO TRIP RELAY

ONE SET FOR EACH SIGNAL PATH

ONLY ONE REQUIRED FOR AN SPS SCHEME

VIRTUAL MAPPING OF CONTACTS

SPS FOR KOODANKULAM• CONTINGENCY LEVEL ABOUT THE SAME AS

TALCHER-KOLAR– SINGLE UNIT TRIPPING : 1000 MW– STATION LOSS : 2000 MW

• LARGE DIPS IN FREQUENCY LIKELY• CONVENTIONAL PROTECTION SCHEMES

MIGHT BE INADEQUATE• LARGE INCREASE IN NORTH-SOUTH FLOWS

LIKELY DUE TO TRIPPING– OSCILLATIONS IN THE SYSTEM– REDUCED SECURITY– TRUNK CORRIDOR LOADING

SUGGESTED FEATURES• SCHEME TO BE MADE PART OF THE PROJECT• GRANULARITY OF SIGNAL TO BE GENERATED TO BE

DECIDED– ONE SIGNAL ON ONE UNIT TRIP– SECOND SIGNAL ON BOTH UNITS TRIP

• SIGNAL WOULD BE TRANSMITTED THROUGH WIDEBAND TO LOCATIONS DECIDED FOR TALCHER-KOLAR INTER TRIP

• SIGNAL TO BE TRANSMITTED THROUGH WIDEBAND FROM KOODANKULAM TO KOLAR

POWER DEMAND OVER-RIDEGAZUWAKA POLE1

POWER DEMAND OVER-RIDEGAZUWAKA POLE2

BHADRAWATHI

400kV Hosur-Salem SPS

Congestion Management in SR: Between S1, S2 bid area

Snapshot of 400kV Hosur-Salem flow 725MW on 19-Jan-2010 18:52 Hrs

• IN N-1 CONDITION, 400KV HOSUR-SALEM AND 400KV SOMANAHALLI-SALEM GETTING SEVERELY LOADED.

• CASCADE TRIPPING AND SEPARATION CANNOT BE RULED OUT

• TO LIMIT THE POST CONTINGENCY FLOW BELOW 800MW, IT WAS DECIDED TO PUT LIMIT ON S1-S2 Ʃ OF S2 MEMBERS SCHEDULE.

• AFTER CONDUCTING LOAD FLOW STUDY, SCHEDULE DECIDED FOR S2 AREA CONSTITUENTS WAS 5000MW WITH FULL NEYVELI COMPLEX AVAILABILITY.

Congestion Management in SR: Between S1, S2 bid area

SPS for Hosur – Salem…….

• Intent: To relieve post contingency(N-1) stress

on 400kV Kolar-Hosur-Salem and 400kV

Bangalore-Salem

• Scheme: disconnection of about 300 MW in

and around Salem after sensing of line trip in

the above corridor. This would increase TTC by

80-100 MW

SPS for Congestion Management: Between S1,S2 Bid Area

HVDC Kolar import-2300 MW

HVDC Gazuwaka Import-600 MW

HVDC Bhdrawati Import-500 MW

Base Case

690615

361

394

92x2

677x2

511

561

GOOTY

364

270

486

420

334X2

139

250X2

234

67x2

Voltages

Kolar-393 KV

Hosur-386 KV

Salem-387 KV

Somanahalli-389 KV

Neelamangala-390 KV

Hoody-390 KV

Udumalpet-393 KV

NLYTs2-401 KV

KV Pattu-376 KV

SRPD-398 KV





908

322

352

164x2

441x2

478

573

GOOTY

460

205

520

460

350X2

293

254X2

400kV Hosur-Salem-OUT

356

152x2

Voltages:

Kolar-386 KV

Hosur-379 KV

Salem-382 KV

Somanahalli-383 KV

Nelamangala-383 KV

Hoody-383 KV

Udumalpet-390KV

NLYST2-399 KV

KVPattu-370 KV

SRPD-372 KV





785

327

357

140x2

403x2

419

512

GOOTY

440

205

515

455

325X2

206

234X2


351

180x2

With load shedding of 300 MW at Salem

Voltages

Kolar-399 KV

Hosur-392 KV

Salem-392 KV

Somanahalli-392 KV

Neelamangala-395 KV

Hoody-395 KV

Udumalpet-396 KV

NLYTs2-403 KV

KV Pattu-399 KV





575708

356

388

103x2

980

493

563

GOOTY

415

243

516

435

340X2

185

251X2

285

105x2

400kV Kolar-Hosur one circuit -OUT

Voltages

Kolar-390 KV

Hosur-379 KV

Salem-383 KV

Somanahalli-384 KV

Neelamangala-389 KV

Hoody-389 KV

Udumalpet-391 KV

NLYTs2-400 KV

Kv Pattu-376 KV





814

328

358

143x2

643

413

512

GOOTY

455

152

512

418

328X2

219

234X2


364

191x2

With load shedding of 300 MW at Salem

400kV Kolar-Hosur one circuit -OUT

Voltages

Kolar-397 KV

Hosur-385 KV

Salem-391 KV

Somanahalli-390 KV

Neelamangala-393 KV

Hoody-393 KV

Udumalpet-395 KV

NLYTs2-403 KV

Kv Pattu-382 KV

400kV Vijayawada-

Nellore SPS

400 KV GRID MAP OF SOUTHERN REGION

Snapshot of 400kV Vijayawada-Nellore 550MW each and Low Voltages in Sothern part of SR on 25-02-2010 18:44 Hrs

Snapshot of 400kV Vijayawada-Nellore 580MW each and Low Voltages in Sothern part of SR on 17-03-2010 16:32 Hrs

Snapshot of 400kV Vijayawada-Nellore 600MW each and Low Voltages in Southern part of SR on 18-03-2010 16:43 Hrs

450

470

490

510

530

550

570

590

610

630

6500:

00

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23:0

0

0:00

Time in HH:MM ---->

Flo

ws

in M

W -

--->

Graph of 400 KV Vijayawada – Nellore lines Flows on 30-Mar-10

440

460

480

500

520

540

560

580

6000:

00

1:00

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0:00

Time in HH:MM ---->

Flo

w in

MW

---

-->

400 KV Vijayawada - Nellore - I 400 KV Vijayawada - Nellore - II

Typical Day 400 KV Vijayawada – Nellore Flow(07–April–10)

0

100

200

300

400

500

600

700

800

9000:

00

1:00

2:00

3:00

4:00

5:00

6:00

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10:0

0

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Vijayawada - Nellore Ckt I Vijayawada - Nellore Ckt II

Flow on Ckt 2 while

tripping of Ckt 1

788 MW

Graph of 400 KV Vijayawada – Nellore lines Flows on 15-Apr-10

• Intent: To relieve post contingency (N-1) stress on

400kV Vijayawada-Nellore.

• Scheme: Reduction of Generation about 400 MW

in Vemagiri complex and LANCO(STAGE-2) on

tripping of one circuit when flow is more than 550

MW each.

• Status: APTRANSCO agreed in principle

SPS FOR VIJAYAWADA NELLORE

SPS ACTIONREDUCTION AT LANCO-

VEMAGIRI COMPLEX

VEMAGIRI

VIJAYAWADA

KHAMMAM

ALMATTI

NELLORE

402314x2438x2

SRISAILEM

STEADY STATE LIMIT OF EACH CKT OF VJA-NLR are:1) WITH NO COMPENSATION: 630 MW2) WITH REATORS AT ONE END:548 MW3) WITH REACTORS AT BOTH ENDS : 452 MW

* 400KV VIJAYAWADA-NELLORE-2 NELLORE END RECTOR OUT

VTS

LANCO VEMAGIRI COMPLEX GEN.1) GMR-VEM – 365 MW2) GOUTHAMI – 460 MW3) KONASEEMA –430 MW4) JEGURUPADU2-225MW

LANCO GENERATION: 350 MW

571x2

387x2

179x2404x2

Study for Requirement SPS for 400kV Vijayawada-Nellore outage

VEMAGIRI

VIJAYAWADA

KHAMMAM

ALMATTI

NELLORE

497299x2418x2

SRISAILEM



VTS


LANCO GENERATION: 350 MW

805

328x2

233x2458x2

400KV VIJAYAWADA-NELLORE ONE CIRCUIT OUT


VEMAGIRI

VIJAYAWADA

KHAMMAM

ALMATTI

NELLORE

426255x2356x2

SRISAILEM



VTS


LANCO GENERATION: 260MW

715

273x2

180x2405x2

400KV VIJAYAWADA-NELLORE ONE CIRCUIT OUT AND 430 MW GENERATION BACKDOWN

Generation reduced at VEMAGIRI COMPLEX and LANCO1) GMR-VEM – 90 MW2) GOUTHAMI – 100 MW3) KONASEEMA –100 MW4) JEGURUPADU2-50MW5) LANCO- 90 MW


Muddanur SPS

Study for Requirement SPS for Muddanur Generating station

966 MW

PULIVENDULA

MUDDANUR

ANATHAPUR

YERRAGUNTLA

CHINAKAMPALLI

44X2

234X2

112X294X2

WITH FULL GENERATION AT MUDDANUR

RADIAL

RADIAL


966 MW

PULIVENDULA

MUDDANUR

ANATHAPUR

YERRAGUNTLA

CHINAKAMPALLI

47X2

401

128X2109X2

ONE CKT of 220kV Muddanur-Chnakampalli OUT

666 MW

PULIVENDULA

MUDDANUR

ANATHAPUR

YERRAGUNTLA

CHINAKAMPALLI

42X2

230

106X270X2

SPS ACTION: REDUCE GENERATION BY 300 MW OR TRIP ONE UNIT AND REDUCE 100 MW

RADIAL

RADIALRADIAL

RADIAL


966 MW

PULIVENDULA

MUDDANUR

ANATHAPUR

YERRAGUNTLA

CHINAKAMPALLI

65X2

214X2204X2

Both CKTs of 220kV Muddanur-Chnakampalli out

566 MW

PULIVENDULA

MUDDANUR

ANATHAPUR

YERRAGUNTLA

CHINAKAMPALLI

48X2

138X298X2

SPS ACTION: REDUCE GENERATION BY 400 MW OR TRIP TWO UNIT

RADIAL

RADIAL

RADIAL

RADIAL

Varahi SPS

VARAHI SPS

• More than 450 MW at Varahi and 600 MW of UPCL had to be evacuated through 220kV Varahi-Shimoga D/C line and 220kV Kemar-Shimoga S/C circuit.

• 220kV Varahi-Shimoga D/C line severly loaded with No N-1 reliability.

• In case of tripping of one of the circuits generation to be backdown at Varahi and UPCL

VARAHI

(450MW)

SHIMOGA

KEMAR

SHARAVATHI

UPCL

(600MW)

KAVOOR

PUTTUR

Conectivity of VARAHI AND UPCL:

VARAHI SPS

Load is around 300 MW

Lines severly load with no N-1

Another unit of UPCL is in pipe line. So SPS at varahi is very much necessary

NAGJHERI SPS

NAGJHERI SPS

KAIGA

KADRA

KODASALLI

NAGJHERI

AMBEWADI

HUBLI

BIDNAL

NARENDRA

BELGAM

1. Nagjheri Gen 850MW

2. Kodasalli Gen 120 MW

3. Kadra Gen 150 MW

4. Kaiga Gen 660 MW

All 220 kV lines in Nagjheri area are in service

156MWx2

150MWx2

23MWx2

2MW

70MWx2

86MW

80MWx2

77MW

96MW

144MWx2

144MWx2

PRESENT SPS WAS DESIGNED TO MONITOR NJPH-KODASALLI FOR REVERSAL AND TRIP UNITS TO PROTECT KAIGA (WHEN KAIGA UNITS WERE EVACUATED THROUGH 220 KV)

152MWx2

NAGJHERI SPS

KAIGA

KADRA

KODASALLI

NAGJHERI

AMBEWADI

HUBLIBIDNAL

NARENDRA

BELGAM



3. Kadra Gen 150 MW

4. Kaiga Gen 660 MW

220kV Nagjheri-Bidnal one line tripped

In this case 220kV Nagjheri-Hubli/Bidnal line and 220kV Nagjheri- Ambewadi line are getting over load

To bring flows to normal there is a requirement to trip one Nagjheri Unit(150MW)

185MWx210MWx2

5MW

70MWx2

191MW

58MWx2

95MW

103MW

150MWx2

168MWx2

161MWx2

185MW

NAGJHERI SPS

KAIGA

KADRA

KODASALLI

NAGJHERI

AMBEWADI

BIDNAL

NARENDRA

BELGAM



3. Kadra Gen 150 MW

4. Kaiga Gen 660 MW

220kV Nagjheri-Hubli/Bidnal TWO lines tripped

In this case 220kV Nagjheri-Hubli/Bidnal line and 220kV Nagjheri- Ambewadi line are getting over load

To bring flows to normal there is a requirement of Two Nagjheri Units tripping(150MW each)

10MWx2

16MW

81MWx2

141MW

13MWx2

123MW

113MW

160MWx2

197MWx2

232MW

138MWx2

HUBLI

226MW

PMU’s Proposed

Ramagundam Islanding scheme

Thank You

special protection schemes

Documents

system variables

entire system

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particular system condition

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restructuringwhy sps

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