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117th PCM MAIL LIST 1) Chief Engineer (LD), MSETCL, Kalwa.Fax-27601769/65 2) Chief Engr. (Trans O&M), MSETCL, Bandra. Fax No. 022 26598587. 3) S.E. (T&C), MSETCL, Aurangabad Fax-0240-2234220 /2346290 4) S.E (T&C), MSETCL, Pune. Fax-9520-2617532/2612342 5) S.E. (T&C), MSETCL, Nagpur. Fax-95712-2234220 6) S.E.(T&C), MSETCL, Nasik Road Fax-0253-2462422 7) S.E.(T&C), MSETCL, Vashi Fax--022-27662055 8) S.E.(Gen.Tstg), MSPGCL,Eklahre, Nasik Fax-95253-2810496/2810499 9) S.E. (Task Force), MSPGCL, Nagpur Fax- 0712-2591717. 10) S.E.(TCC), MSETCL, Karad. Fax.No. 02164 255118 11) Chief Engineer (Gen), GSECL, H.O. Baroda. Fax-0265-5512129/2344537 12) Addl. C.E.(Testing), GETCO, Baroda. Fax-0265-2351218 13) Chief Engineer(LD), MPPTCL, Jabalpur. Fax-0761- 2664343 /2282632. 14) E.D. (T&C),MPPTCL, Jabalpur. fax-0761-2661696 15) Addl.C.E., MPPGCL, Jabalpur Fax- 0761-2660063/2665805 16) Chief Engineer (LD), CSPTCL, Bhilai. Fax-0788-2282632/0788-383633 17) C.E. (T&C), CSEB, Raipur.Fax-0771-4066988/07759-226227 18) EE (T) , CSPGCL- Fax.No. 07789-226227 19) S.E.(T&C), CSPTCL, Bhilai. Fax.No. 0788 2281 20) S.E.(T&C), CSPTCL, Raipur. Fax No.0771-4066988. 21) E.E.(T&C), CSPTCL, Bhilai. Fax No. -0788 2281561 22) EE, Division VIII(MRT),Elect. Dept; Goa Fax 0832-2735124. 23) Supdt.Engr., Electricity Dept., DNH, Silvasa. Fax : 0260-2642338 24) Executive Engr., Electricity Dept. DD. Fax : 0260-2250889 25) D.G.M.(O.S. ),N.T.P.C., Mumbai, Fax- 28216692 26) D.G.M.(EM), KSTPS, NTPC, Korba Fax 07759-233088/ 232440 27) DGM (EMD), VSTPS, NTPC, Vindhyachal Fax-07805-247713 28) DGM (EM-I), NTPC, SIPAT Fax-07752-246506/246691. 29) AGM(O&M), KGPP, Adityanagar, Surat Fax 0261-2861428/2861433 30) Sr.Supdt. (EM), Gandhar, NTPC Fax-02642-87402 / 87450 31) DGM (O.S.), WRLDC, Mumbai Fax-28235434 32) DGM, WRTS-I, POWERGRID, Nagpur.Fax-95712-641366/2641496 33) Addl General Manager, WRTS-II, POWERGRID, Baroda Fax-0265-2480952 34) SME (E), TAPS-3&4,Tarapur Fax 02525-282001/282073 35) Maintenance Superintendant, TAPS –1 & 2,Tarapur.Fax- 02525-282121 36) SME(E), NPCIL , Kakrapara Fax 02626-234266 37) GM(Maint.). TORRENT Power., Ahmedabad.Fax-079-27506679 38) AGM (ET&A),TPC, Trombay. Fax –022-66687088 39) Dy.Gen. Manager, Dahanu TPS Fax- 952528-222576 40) Vice President, Reliance Energy, Mumbai Fax-30094488 41) GM (Electrical), JPL, Raigarh. Fax.No.7767-281995,281993. 42) AGM(OS), NSPCL, New Delhi . Fax.No.011 26717363/26717366 43) Vice President, APL, Ahmedabad 44) GM, RGPPL, Anjanwel, Guhagar, Ratnagiri, Fax.No. 02359 241071 45) GM, JSW Energy Ltd., Jindal Mansion, Mumbai- Fax.No.022 23526400 46) GM, CGPL, Mundra. Fax.No. 02838 661188 47) Director (G M Division), CEA, New Delhi. Fax.No.011-26109750

1 Minutes of the 117th Protection Committee of WRPC held on 03rd & 04th June 2013 at CGPL Mundra.

MINUTES OF THE 117th PROTECTION COMMITTEE MEETING OF WRPC

HELD ON 03/04.06.2013 AT CGPL MUNDRA

The 117th meeting of the Protection sub-Committee was held at CGPL Mundra on 03rd & 4th

June 2013. The list of participant is enclosed at Annex-1.

Shri K.K. Sharma Executive Director CGPL welcomed the participants of the meeting. He

stated that in the year of 2005-06, MoP, GoI undertook the initiative to promote and facilitate

installation of Ultra Mega Power Plants(UMPP) in India. 14 such projects were envisaged

and CGPL is the first UMPP commissioned in India. It is also the first Power plant in the

country where 800MW unit has been commissioned and also CGPL has achieved the

commissioning of the plant ahead of the schedule.

Shri S.D. Taksande, Member Secretary, WRPC welcomed the participants of the meeting. He

thanked CGPL for consenting to host the meeting at a short notice and making excellent

arrangements for the stay of the participants and arranging the meeting in such a immaculate

way. He further stated that the first NPC meeting was held at New Delhi on 15.04.2013,

wherein issues regarding GSES, ADMS, AULFS, df/dt and the quantum of Load Shedding

(LS) etc., were deliberated in detail. Post 30th /31st July 2012 disturbance, lot of activities

have been undertaken such as formulation of SPS, formulation of implementation of GSES,

ADMS and AULFS in WR and as such role of protection committee of WRPC has become

more significant. Many important protection related issues were dealt and finalized by PCM

group which a meeting to finalize load management of DD/DNH to relive the GETCO

network was also held on 21st March 2013. Also, important issues such as Zone-3 settings,

SPS of CGPL and Sugen Islanding Scheme have also been included in the agenda. He hoped

that the discussions on the above would evolve suggestion/recommendations so that the

disturbances are minimized. He then requested Shri Satyanarayan S., Superintending

Engineer (C&P), WRPC to take up the agenda items for discussion.


ITEM NO.1: CONFIRMATION OF MINUTES OF 116th PROTECTION

COMMITTEE MEETING.

Superintending Engineer (C&P), WRPC informed that the minutes of 116th PCM, held on

30th & 31st January 2013 at Nagpur, were circulated vide WRPC letter No.

Prot./116PCM/2013/WRPC-2937 dated 15.03.2013. No comments have been received.

The minutes of the meeting circulated vide above letter was confirmed.

ITEM NO.2: SYSTEM DISTURBANCES

2.1: System disturbances in CSPTCL/CSPGCL system.

2.1.1 : Occurrence on 28.03.2013 at 400kV ACBIL, Chhattisgarh : WRLDC representative stated that at 09:00 Hrs, due to R and B phase fault in the 400 kV

ACBIL-Bilaspur 1 & 2, both lines tripped on Zone 1 DPR operation, resulting in complete

loss of evacuation from ACBIL. Unit 1 and 2 (2 X 135 MW) tripped on under voltage relay

operation along with Spectrum Unit (50 MW). This led to generation loss of 254 MW. The

400/6.9kV ST-1 & 2 tripped on REF & Differential protection. ACBIL Unit 1 & 2 tripped on

operation of A,B Class protection,86 A,86 B. The 132 kV Ratija 1and 2 lines tripped on over

voltage.

He further stated that the DR of ACBIL indicates that fault location was at 55 Km and the

line length is nearly 55.4 Km. The line tripped at Bilapsur end on receipt of DT. No fault was

found during patrolling.

Unit1 was light up by 13:00 Hrs. The Bus at Ratija was charged through 132 kV Ratija 1and

2 lines.

Committee felt that the R & B transient fault on D/C line is rare. Also, the DPS of both

the lines have overreached, therefore the line settings of 400kV ACBIL-Bilaspur 1 & 2

lines needs to be reviewed.

It was requested to submit the DRs for proper analysis of such events in future.

2.1.2 : Occurrence on 02.04.2013 at 400kV LANCO (Pathadi) TPP, Chhattisgarh : WRLDC representative stated that at 20:20 Hrs, due to heavy wind at LANCO thermal power

station, the tin cladding sheet fall on B Phase of GT bay and ST bay, leading to tripping of


Unit 1 on overall differential protection, while ST-2 tripped on REF protection.

At 20:23 Hrs, Y and B phase fault occurred on Bus I which led to bus bar protection

operation. ST 1 and 400 kV Pathadi-Sipat which were on Bus I tripped along with Bus

Coupler with the operation of Bus bar protection. The BB protection might have operated due

to falling of tin cladding sheet on B phase or Y phase of the Bus I and coming into the

induction zone. It was also observed that several jumpers are broken and they may have come

into the induction zone of Y and B phase of Bus I.

At the same time 400 kV Pathadi-Korba line tripped from Korba end in Zone-1.

Bus Bar Arrangement at 400 kV LANCO (Pathadi) S/s

Bus I Bus II

ST 2 Unit 2 ,GT 2

Unit 1, GT 1 ST 1

400 kV Pathadi –Sipat 400 kV Pathadi – Korba

The Generation loss due to tripping of LANCO Unit 1 was 268 MW. Unit 1 was

synchronized at 16:49 Hrs on 03rd April ’13. The Bus I was taken in service on 04-03-13.

Committee felt that though the operation of Bus bar protection was in order, tripping of

400 kV Pathadi – Korba line in Zone -1 from Korba end was undesirable. The relay

settings of 400 kV Pathadi – Korba line at Korba end need to be checked for over reaching

and corrected if required.

2.1.3 : Occurrence on 19.03.2013 at 220/132 kV Raigarh S/S, Chhattisgarh:

CSPTCL representative stated that at 15.05 hrs., while taking the shutdown on 220/132 kV,

160 MVA ICT I at 220 kV s/s Raigarh, it was getting discharge after opening of isolators

from both end. At that time the insulator disc flashover occurred on 220 kV side B-phase CT

of ICT I and it fell on Bus II along with the jumper. This led to bus fault on 220 kV Bus II.

There is no Bus bar protection at 220 kV Raigarh substation and all feeders connected to

both buses tripped from remote ends (Bus coupler is also damaged).

The load loss due to tripping distribution lines was 347 MW. Restoration of the system was

completed by 19:03 Hrs.

The Committee observed that the tripping was in order and recommended commissioning

of Bus Bar protection at 220 kV Raigarh substation at the earliest.


2.1.4.Occurrence on 28.01.2013 at Balco, Chhattisgarh:

WRLDC representative stated that at 12:01 Hrs, the 400 kV Balco-Korba line was opened as

per the planned shutdown. During the opening of this line from Korba end, 400 kV Balco-

Birsinghpur line got tripped due to over voltage. This led to no evacuation path for the Balco

generating plant leading to tripping of its Units 1 & 2 (67.5MW each) on over frequency

protection.

The generation loss due to tripping of Units was 106 MW. The 400 kV Balco –Birsinghpur

line was charged at 12:54 Hrs. 400 kV Balco-Korba was taken in service at 14:15 Hrs. Unit-2

was synchronized at 16:47 Hrs.

Committee observed that the cause of O/V might be due to opening of Balco-Korba line and

recommended that WRLDC may do complete analysis/study to ascertain violation of

system parameters in study/analysis, prior to giving clearance to open the lines.

2.2. System disturbances in GETCO/GSECL system.

2.2.1 : Occurrence on 21.02.2013 at 220kV Vapi (GETCO) S/S : GETCO representative stated that at 10:11 Hrs, B-Phase jumper of 220 kV Vapi (GETCO) -

Vapi (PG) line on Bus-II detached from B-Phase pole and fell on the ground. The line

breaker tripped on zone 1 but at the same time B-Phase breaker pole did not trip which led to

operation of LBB protection and all the feeders connected on Bus-II tripped. The 220 kV

Vapi (GETCO) - Bhilad and 220 kV Vapi (GETCO) -Tarapur on Bus I tripped on operation

of Back-up relay and Zone-2 from remote end.

The Bus arrangement was as follows

Bus I Bus II 220 kV Vapi(GETCO)- Tarapur 220 kV Vapi(GETCO)- Ambethi 220 kV Vapi(GETCO)-Bhilad 220 kV Vapi(GETCO)- Vapi(PG) 220 kV Vapi(GETCO)- Kakrapara I 220 kV Vapi(GETCO)- Kakrapara II Vapi(GETCO) 220/66 kV 100 MVA ICT III Vapi(GETCO) 220/66 kV 100 MVA ICT I Vapi(GETCO) 220/66 kV 100 MVA ICT IV

Vapi(GETCO) 220/66 kV 100 MVA ICT II

The load loss was 300MW. Bus II was charged through bus coupler at 10:30 Hrs.

Immediately 220/66 kV 100 MVA ICT II, III and IV were charged and load were restored.

However 220/66 kV 100 MVA ICT I was kept off in order to attend fault as 220 kV

Vapi(GETCO)-Vapi (PG) line and ICT I are connected to common bus isolator. Also to


restrict the loading of other ICT in the absence of ICT I ,around 70 MW load restriction

measures were taken in DD and DNH. ICT I was restored at 16:15 Hrs.

Committee felt that the tripping of 220kV Vapi (Getco) – Bhilad & Vapi (Getco) – Tarapur

on operation of Back-up relay and Zone 2 from remote ends ahead of LBB protection was

undesirable. The relay settings of these lines need to be tested and relay settings be

coordinated appropriately. Also the LBB relay may be tested for time settings, since the

above lines connected to Bus-I tripped on B/u & Zone-2 timings.

2.2.2 : Occurrence on 03.02.2013 at Ukai Thermal Power Plant, Gujarat: GSECL representative stated that at 18:02 Hrs on 03.02.2013, there was a fault due to

flashover of HV Side Y-Phase lightening arrester of 220/400 kV 315 MVA ICT at Ukai

Thermal Power plant which was not cleared by the transformer protection leading to LBB

operation of Bus II. Elements connected to the bus got tripped with generation loss of 150

MW (Unit -3 tripped).

At 18:44 Hrs, due to mal-operation of LBB protection of Bus-I all elements connected to it

got tripped. This led to generation loss of 265 MW (Unit 2 and 4 tripped).The total loss of

generation during these two incidents was around 415 MW.

Bus Bar Arrangement at 220 kV Ukai TPS

Bus I Bus II

GT 2,4 GT 1,3,5

ST 1,3,4 ST 2

220 kV Ukai-Ukai(H) I 220 kV Ukai-Ukai(H) II

220 kV Ukai-Acchalia II 220 kV Ukai-Acchalia I & III

220 kV Ukai-Mota I 220 kV Ukai-Mota II

400/220 kV 315 MVA ICT

The Generation loss due to tripping of Units was 415 MW. Restoration was completed by

synchronization of UTPS Unit 4 at 00:37 Hrs on 04-02-13. The bus-bar protections are in

service.

Committee observed that the transformer differential protection/Bus Bar protection

should have operated. The Bus Bar protection/LBB protection should be checked and

tested.


2.3. System disturbances in MPPTCL/MPPGCL system.

2.3.1 : Occurrence on 08.04.2013 at ATPS Chachai :

MPPGCL representative stated that at around 18:42 Hrs. on 08.04.2013, 'Y' – Phase CT of

220 kV ATPS-Anuppur Ckt. –I got burst and its flame created the bus fault, resulting in all

connected Generators and 220 kV feeders at ATPS Chachai to trip, resulting in complete

supply failure of 220 kV Bus. Due to jerk 132 kV Bus became dead hence 132 kV feeders

were hand tripped at ATPS. Consequently total 220 kV & 132 kV supply at ATPS failed and

interruption occurred at ATPS, 132 kV S/s Shahdol, 132 kV S/s Dindori and 132 kV S/s

Kotma.

He further stated that before the occurrence, at ATPS, 120 MW Generator – 4, 220/132 kV,

63 MVA Auto X-mer(New) and 132/133 kV, 40 MVA BHEL X-mer was under shut down.

220 kV ATPS - Birsinghpur Ckt. –III was open from ATPS end. Remaining Generators and

220 kV, 132 kV feeders at ATPS were in charged condition and normally loaded.

220 kV and Station Supply of Power House-II & III at ATPS was resumed by Charging the

220 kV ATPS – Jabalpur Ckt. – I & II at 19.00 Hrs. Subsequently 132 kV and 33 kV supply

at ATPS was resumed and 18 feeders / transformers were charged Synchronized at 23:47 Hrs.

& 05:27 Hrs on 09.04.2013

Total generation loss of approx. 300 MW.

The ABB make Bus Bar protection scheme was under repairs.

Committee felt that the CT might have busted due to insulation failure, since the

transmission corridor is High Voltage prone. The tripping of elements from remote end in

the absence of BB protection was in order. The BB protection should be put into service at

the earliest.

2.3.2 : Occurrence on 12.04.2013 at ATPS Chachai

MPPGCL representative stated that at around 21.28 Hrs on 12.04.2013 fire and blasting

sound was observed in 220 kV substation and the 220 kV Bus and 132 kV Bus become dead.

On inspection of 220 kV switchyard it was found that the B phase CT & Y pole Breaker pole

of 220 kV Jabalpur feeder No 2 got busted. The Breaker pole interrupter fell on ground along

with Y Phase 89 C Isolator of Pole breaker.

The 120 MW Generator No. 4 tripped on U/V, Neg Seq. Protection & 210 MW Generator

No. 5 tripped on Back up Impedance.


He further informed that prior to tripping at 21.00 Hrs on dated 12.04.2013, the system at

ATPS 220/132kV substation was running normal along with generator & feeders.

Protection & Indication at Remote End

220 kV Jabalpur Fdr No. 1 ABC-N , Z 2

220 kV Jabalpur Fdr No.2 ABC –N, Z 2

220 kV Sukha Feeder Trip ABC, CN Phase, Z 2, DPR Optd

220 kV Sidhi Feeder Trip ABC, CN Phase, Z 1, SOTF

220 kV Anuppur Fdr No.2 Trip ABC, C G Phase

132 kV Anuppur Fdr No. 2 C G Phase E/F

The 220 kV and Station Supply of Power House – II & III at ATPS was restored by Charging

the 220 kV ATPS – Birsinghpur Ckt. –III at 21:51 Hrs. Subsequently 132 kV and 32 kV

supply at ATPS was restored and 18 feeders/transformers were charged/synchronized at

03:05 Hrs on 13.04.2013, at 03:25 Hrs on 13.04.2013 and 07.43 Hrs on 13.04.2013

respectively.

Total generation loss of approx.388 MW.

Committee felt that in absence of BB protection, tripping of lines from remote ends was in

order. However tripping of 220kV ATPS-Chahchai –Sidhi line in Zone 1 & SOTF from

Sidhi end and 132kV Anuppur fdr. No.2 on E/F was not desirable. The relay settings of

ATPS-Chahchai –Sidhi line and 132kV Anuppur fdr. No.2 should be checked/tested.

2.3.3 : Occurrence on 14.04.2013 at ATPS Chachai

MPPGCL representative stated that at around 03:35 Hrs on 14.04.2013, 'B' –Phase PT of 220

kV Main Bus-II at ATPS burst and hit the top insulator of (caused it to break) 'Y' –Phase PT

and its top jumper fell on the ground thereby creating the bus fault. This resulted in tripping

of the all connected Generators and 220 kV feeders at ATPS from remote ends. There was a

complete supply failure of 220 kV Bus and 132 kV Bus became dead. Due to this interruption

occurred at 132 kV S/s Shahdol, 132 kV Dindori and 132 kV S/s Kotma and in other 11 S/Ss.

He further informed that before the occurrence at ATPS, 120 MW Generator -3, 220 kV

ATPS-Jabalpur Ckt. –II, 220 kV ATPS-Anuppur Ckt. –I and 132/33 kV, 40 MVA BHEL X-

mer was under shut down. 132 kV ATPS –HJIM Ckt. (Industrial Feeder) was ideally charged

(not loaded). Remaining Generators and 220 kV, 132 kV feeders at ATPS were in charged

condition and normally loaded.


Lines were restored by 05:24 Hrs. The 210 MW, Genertor No.- 5 at ATPS –Synchronized at

23:47 Hrs. The 120 MW, Generator No.-3 at ATPS- Synchronized at 05:27 Hrs. on

09.04.2013

The 'B' –Phase PT and 'Y' –Phase top insulator has been replace and bus charged at 09:45

Hrs. on 17.04.2013.

Committee felt that in absence of BB protection, tripping of lines from remote ends was in

order. The BB protection should be put into service at the earliest.

2.3.4 : Occurrence on 16.03.2013 at 220kV Pitampur

MPPTCL representative stated that at 05:38 Hrs on 16.03.2013, 220 kV Pithampur –

Badnagar Ckt (which was on Main Bus-I) tripped from both end on Phase –A-N, Zone -1

At 220 kV S/s Pithampur LBB of Transfer Bus Coupler operated causing the bus bar

Protection to operate and resulting in tripping of Bus Coupler Breaker & 220 kV Pithampur-

Rajgarh (PGCIL) Ckt.-I from 220 kV S/s Pithampur end.

At the same instant i.e., at 05:38 Hrs, 220 kV Pithampur-Rajgarh (PGCIL) Ckt-II (which was

on Main Bus-II) also tripped from both ends with following indications:

At 400 kV S/s Rajgarh (PGCIL) end: DP received on Channel -1, Master Trip relay operated

-86A, 86B. At 220 kV S/s Pithampur end: Type C-A, Zone-1.

Due to above trippings both Main Bus-I & II became dead at 220 kV S/s Pithampur.

Consequently 220 kV & 132 kV supply failed at 20 kV S/s Pithampur resulting in failure of

132 kV supply at 132 kV S/s Pithampur, 132 kV S/s Betma, 132 kV S/s Bagdi & 132 kV S/s

Jamli and interruption occurred on 13 feeders / transformers.

Before the occurrence, at 220 kV S/s Pithampur, 220 kV Pithampur –Indore Ckt was open

from 220 kV S/s Pithampur end. 132 kV Pithampur-Indore WZ & 132 kV Pithampur –Indore

SZ Ckt. was open from 132 kV S/s Pithampur end. 220 kV Pithampur-Badnagar Ckt was

charged through Transfer Bus and 132 kV Pithampur –Bhanu Steel Ckt. (Industrial Feeder)

was not of service at 220 kV S/s Pithampur. Remaining 220 kV & 132 kV feeders at 220 kV

S/s Pithampur were in charged condition and normally loaded.

At 06:10 Hrs, supply was restored from 132 kV S/s Pithampur through 132 kV

Interconnector –I & II and subsequently 13 feeders / transformers were charged at 06:42 Hrs.

The matter was taken up with GE for resolving the mal operation of LBB protection. Committee felt that due care should be taken during relay settings. Further line PTs should

be installed and wired up for line protections.


2.3.5 : Occurrence on 29.01.2013 at 220kV Pitampur S/S

MPPTCL representative stated that at 10:26 Hrs, on 29.01.2013, 132 kV Pithampur –Betma

feeder tripped on O/C R-phase and B-phase indication, consequently 220/132 kV, 160MVA,

NGEF X-mer-I tripped on OLTC Buchholz (OSR R-phase). Load trimming scheme

connected on X-mers operated & tripped the 132 kV Jamli feeder & 132 kV Bagdi feeder

giving load relief of 44 MW . Even after the operation of load drop scheme there was an

approx. load of 200 MW shifted on 220/132 kV , 160 MVA X-mer-II, caused the tripping of

this 160 MVA X-mer –II on O/C R-phase indication at 10:28 Hrs and resulted in tripping of

following feeders:-

1. 132 kV Mid India Ckt. (CPP)

2. 132 kV Bridge Stone Ckt. (industrial feeder)

3. 132 kV Parasrampuriya Ckt. (Industrial feeder)

4. 132 kV Hindustan Motor Ckt. (Industrial feeder)

5. 132 kV inter-connector – I & II

6. 132/33 kV, 40 MVA X-mer – I & II at 220 kV pithampur S/s

7. 132/33 kV, 63 MVA X-mer-at 220 kV Pithamur S/s.

8. 132/33 kV, 20 MVA X-mer at 220 kV Pithamur S/s.

Before the occurrence at 220 kV Pithampur S/s all the 220 kV and 132 kV feeders were in

charged condition and normally loaded (252 MW).

Supply was resumed by charging 132 kV inter-connector –I & II at 10:55 Hrs. Subsequently

11 feeders / X-mers were charged by at 12:55 Hrs. At 12:05 Hrs, 132 kV Pithampur – Betma

Ckt. charged via Bus Coupler as lock out contactor coil of its main breaker got burnt while

charging the 132 kV Pithampur – Betma feeder.

Committee felt that OLTC Buchholz relay of T/F shouldn’t have operated. Tripping of T/F-

II on over current due to insufficient load trimming was in order. However excess load not

in commensurate with the transformer loading capacity should be included in the load

trimming scheme.

2.3.6 : Occurence on 18.04.13 at 220kV Pithampur S/S

MPPTCL representative stated that at 15:28 Hrs on 18.04.2013, 220 kV Pithampur – Indore

Ckt tripped from 220 kV S/s Pithampur end on Type – CG, Zone – I, Distance – 16.4 Km.

indications resulting LBB to operate and due to mal-operation of LBB the Bus Bar protection

of 220 kV Main Bus – I & II operated. Consequently 132 kV supply at 220 kV S/s

Pithampur, 132 kV S/s Pithampur, 132 kV S/s Betma, 132 kV S/s Bagdi & 132 kV S/s Jamli


failed and following feeders/transformers tripped.

1. 220/132 kV, 160 MVA X-mer – I & II at 220 kV S/s Pithampur.

2. 220 kV Pithampur – Rajgarh (PGCIL) Ckt. – I & II – from 220 kV S/s

Pithampur end.

At the instant of above tripping 220 kV Pithampur – Badnagar Ckt. did not trip from either

end and hence 220 kV supply was available at 220 kV S/s Pithampur.

Before the occurrence at 220 kV S/s Pithampur, 220 kV Pithampur – Indore Ckt was open

from 400 kV S/s Indore end and was charged from 220 kV S/s Pithampur end. 132 kV

Pithampur – Indore WZ & 132 kV Pithampur – Indore SZ Ckt was open from 132 kV S/s

Pithampur end. 132kV Pithampur–Bhanu Steel Ckt (Industrial Feeder) is out of service at 220

kV S/s Pithampur. Remaining 220 kV & 132 kV feeders at 220 kV S/s Pithampur were in

charged condition and normally loaded.

Supply at 132 kV S/s Pithampur was resumed at 15:35 Hrs by charging 132 kV Pithampur –

Indore WZ & 132 kV Pithampur – Indore SZ Ckt.

Other elements were restored by 16:20hrs. The 220 kV Pithampur – Indore Ckt. declared

faulty and charged at 23:23 Hrs. from 220 kV S/s Pithampur end only.

He further informed that the LBB protection recently commissioned was set wrongly. The time

delay was set to zero. Therefore during the first tripping of 16.03.2013 and this occurrence, after

commissioning of the relay, the relay sensed it as a stuck breaker condition and operated.

There was a problem in Logic of LBB relay which was rectified in consultation with GE

Engineers and taken in Ckt. on 25.04.2013 at 18:25 Hrs.

Committee felt that there was a problem in the logic of Bus selection. Also the time setting

of LBB relay was wrong, resulting in initiation of trip signal to both buses and same should

be corrected.

2.3.7 : Occurrence on 11.01.2013 at 132kV Jaora S/S

MPPTCL representative stated that at 10:45 Hrs on 11.01.2013, 132 kV Ratlam – Jaora Ckt.-I

tripped from both ends due to conductor broke down at location no: 21 & 22 and 132 kV

Ratlam –Jaora Ckt II tripped from 132 kV Jaora end which the following indications:

For 132 kV Ratlam- Jaora Ckt.I

At 220 kV Ratlam end:- DPR opt. 'C' phase, Zone 1,5.22 Km.

At 132 kV Jaora end:- GFC STF WL3, ZM 1 trip, locator 78% Fault Loop L3-N. Trial

charging from 132 kV Jaora end was done at 11:05 Hrs and the line tripped with the

indications – GFC STF WL 3, ZM 1 trip, locator 77.8% Fault Loop L 3-N.


Before the occurrence, Prearranged shut-down was taken on 220 kV Neemuch-Nagda Ckt-I

&II and 132 kV Neemuch-Malhargarh link was kept open for load managment from 09:40

Hrs, dated 11.01.2013. 132 kV supply was available at 132 kV Jaora through 132 kV Ratlam

–Jaora Ckt-I & II and their loading was 69 MW and 70 MW respectively.

Due to tripping of 132 kV Ratlam –Jaora Ckt.-II, total supply failed at the following S/s:

1. 132 kV Jaora

2. 132 kV Daloda

3. 132 kV Mandsaur

4. 132 kV Malhargarh

Supply was restored at 11:00 Hrs. by charging 132 kV Ratlam-Jaora Ckt.-II from 132 kV

Jaora end, consequently the supply of 132 kV Daloda, 132 kV Mandsaur, 132 kV Malhargarh

was resumed by 11:10 Hrs.

After attending the fault 132 kV Ratlam – Jaora Ckt.-I was charged at 16:25.

Committee felt that the tripping was in order.

2.3.8 : Occurrence at 220kV Bhopal S/S on 16.01.2013

MPPTCL representative stated that at 01:06 Hrs, on 16.01.2013, failure of R-Phase pole of

132 kV Breaker of 63 MVA 132/33 kV X-mer at 132 kV Chambal S/s created a 132 kV Bus

fault on 132 kV Main Bus -1 at 220 kV Bhopal S/s consequently 132 kV Bhopal –Bairagarh

Ckt-I, 160 MVA (CGL) & 160 MVA (BHEL) X-mer tripped. 132 kV Bus Coupler was

charged at 01:12 Hrs to shift the load to 132 kV Main Bus-II, at the same instant 3 X 40

MVA X-mer tripped due to non-removal of faulty section, fault persisting and following

trippings occurred-

1. 132 kV Ayodhya Nagar

2. 132 kV Amravat

3. 132 kV Berasiya

Before the tripping, 220 kV Bhopal S/s has an extended bus arrangement for 132 kV Bus

with 132 kV Chamal S/s 132 kV Bhopal – Bairagarh Ckt.-II was open (normally kept open)

from 220 kV Bhopal end.

132 kV Bhopal-Bairagarh Ckt-I, 132 kV Bhopal – Berasiya Ckt, 132 kV Bhopal –Ayodhya

Nagar Ckt, 132 kV Bhopal –Amrawat Ckt. 160 MVA (CGL make) X-mer, 160 MVA (BHEL

make) X-mer and 3x40 MVA X-mer were charged at 1:25 Hrs, 1:32 Hrs, 1:35 Hrs, 1:38 Hrs,

01:43 Hrs, 01:47 Hrs and 01:50 Hrs respectively and system normalised.



2.3.9 : Occurrence on 15.01.2013at 220kV Jabalpur Nayagaon S/S

MPPTCL representative stated that at 17:43 Hrs., on 15.01.2013 'B' Phase 220 kV Ct of

3x40 MVA (which was on Main Bus-II, and at present Bus Bar protection scheme is not in

service) 220/132 kV Mitsubishi transformer bursted due to which the following connected

trippings occurred-

At the instant of above trippings there was no interruption in any area as power was supplied

by 220 kV Amarkantak –Jabalpur Ckt.-I through 160 MVA GEC X-mer which remained in

charged condition.

At 18:20 Hrs 220/132 160 MVA GEC X-mer tripped on overflux indication, consequently

interruption occurred on the following feeders and substations:

1. 220 kV Amarkantak –Jabalpur Ckt.I

2. 132 kV Marhotal

3. 132 kV Jabalpur –VFJ CKT –I & II

4. 132 kV Vinoba Bhave

5. 132 kV Maneri

6. 132 kV Jabalpur –Bargi Ckt-I & II

7. 132 kV Bargi-Lakhnadon Ckt.

8. 132 kV Jabalpur-Shahpura Ckt.

9. 132 kV Jabalpur-Mansakra Ckt.

132 kV supply was restored through 132 kV Shahpura –Jabalpur Ckt at 18:30 Hrs & 63

MVA, 132/33 ABB X-mer charged at 18:32 Hrs and 132/33 kV 63 MVA (VIJAY make) X-

mer charged a 18:34 Hrs and the 14 feeders / X-mers were charged by 19:48 Hrs.

Committee felt that due to tripping of 220 kV Amarkantak – Jabalpur – I, resulting in load

reduction, which in turn might have resulted in high voltage. The over flux relay of

transformer might have operated due to high voltages. Over flux setting of transformer

need to be tested.

2.3.10 : Occurrence S on 13.04.2013 at 220kV Satna S/

MPPTCL representative stated that at 00:51 Hrs, on 13.04.2013, 'Y' –Phase CT of 220 kV

Satna –PGCIL Ckt. –I failed due to transient fault on 220 kV Satna –PGCIL Ckt. –I which

operated the Bus Zone Differential of 220 kV Main Bus-I and hence tripped all the 220 kV

feeders on Main Bus –I, resulting in Main Bus-I to be dead at 220 kV S/s Satna.

Consequently 7 feeders / transformers tripped.

At the instant of above tripping there was no interruption as load of 220 kV S/s Satna & 132


kV S/s Satna was managed by 132 kV Satna –Maihar Ckt. 132 kV Satna-Kymore Ckt., 220

kV Satna –Chhatarpur Ckt. and 132 kV Rewa-Rampur Bhaghelan Ckt.

At around 01:24 Hrs. on 13.04.2013, 132 kV Satna-Maihar Ckt. 132 kV Satna-Kymore Ckt.

and 132 kV Rewa –Rampur Bhaghelan Ckt. tripped due to over load & simultaneously 132

kV Chhatarpur-Bijawar Ckt. also tripped on O/C from 220 kV S/s Chhatarpur end.

Consequently total supply failed at 9 substations.

220 kV supply at 220 kV Satna S/s was restored by charging 220 kV Satna – Kotar Ckt. at

01:31 Hrs. Subsequently 30 feeders / transformers were charged by 02:00 Hrs.

Replacement of 'Y'-Phase CT of 220 kV Satna-PGCIL Ckt.-I is being arranged at 220 kV S/s

Satna.

Committee observed that the trippings were in order.

2.3.11 : Occurrence on 18.02.2013 at 220kV Satna S/S

MPPTCL representative stated that at 21.34 Hrs on 18.02.2013, 132 kV Satna-Kymore Ckt.

tripped in zone-1 due to bursting of R-Phase of MOCB of the line at 220 kV Satna S/s end,

which caused the tripping of 220/132 kV, 160 MVA BHEL & 220/132 kV, 160 MVA

AREVA X-mers from both sides, resulting in complete failure of 132 kV & 33 kV supply at

220 kV Satna S/s. Consequently 14 feeders / transformers were hand tripped.

132 kV supply at 220 kV Satna S/s was restored by charging 220/132 kV, 160 MVA AREVA

X-mers at 21.43 Hrs. Subsequently the 12 feeders/transformers were charged at 21:57 Hrs.


2.3.12 : Occurrence on 23.03.2013 at 220kV Birsingpur S/ S

MPPTCL representative stated that at 16.41 Hrs on 23.03.2013, Y Phase PT of main bus-II at 220 kV Birsinghpur substation got burst and it's jumper fell on Bus-II causing Bus fault. This resulted in tripping of all feeders i.e. 220 kV Birsinghpur-Jabalpur I & II and all inter-connectors i.e. I/C I, II, III & IV, 220 kV Railway traction I & II from far end. This caused interruption at 220 kV S/s Birsinghpur, 132 kV S/s Umariya apart from tipping of SGTPS generators #1,3 & 4 on jerk. The 220 kV breakers of Birsinghpur Substation did not clear the fault which led to voltage & frequency fluctuations in the area, resulting in spread of fault into the system. SGTPS generator#4 tripped immediately after tripping of all the Birsinghpur-SGTPS inter-connector at 16:41:26 "On field failure protection". Other two units 3 & 1 tripped at 16:41:41 & 16:41:45 on MFR due to heavy voltage jerk which was due to tripping of different LOP's of major auxiliaries.


Bus No. 1 of 220 kV S/s Birsinghpur charged at 17.27 hrs by closing 220 kV Birsinghpur-

Jabalpur I. Total generation loss was approx. 550 MW.

Committee observed that the bus-bar protection scheme/module was faulty. This un-

cleared fault led to fall in voltage below hold on voltages of the contactors of auxiliaries,

resulting in failure of auxiliaries thereby tripping of unit 1 & 3. MPPTCL

representative informed that the new BB protection scheme is under commissioning.

2.3.13 : Occurrence on 19.11.2012 at Rajgarh

MPPTCL representative stated that at 10:45 hrs on 19.11..2012, 132 kV Rajgarh – Raghogarh

feeder tripped from 132 kV Raghogarh s/s on DPR Zone-I, AN Phase , FD -45.6 and

resulting in interruption at following s/s

1. 220kV Rajgarh s/s

2. 132 kV Biarora s/s

3. 132 Maksudagarh s/s

4. 132 kV Sironj s/s

220kV Sujalpur (PGCIL) –Rajgarh Cklt-III were opened from 400 kV (440kV) Sujalpur s/s

end at 10:30 hrs and 10:36 hrs respectively on the instruction of shift-in –charge, WRLDC.

Load of 220kV Rajgarh, 132 kV Biaora, 132 kV Sironj and 132 kV Maksudangarh was met

through 132 kV Rajgarh – Raghogarh feeder.

Supply resumed by charging 220kV Sujalpur (PGCIL) –Rajgarh –II and 220/132 kV, 160

MVA transformer at 11:06 hrs and 11:07hrs respectively and supply was restored partially.

Committee observed that though tripping was in order. However it was recommended

that WRLDC may permit opening of only one line at a time out of Sujalpur-Rajgarh –I

& II, since the loads connected through these lines are radial loads.

2.3.14 : Occurence on 08.03.13 at 220kV Ratlam S/S

MPPTCL representative stated that at 11:05hrs on 08.03.2012, ‘B’–Phase 220 kV side CT

(SCT make) of 220/132/33 kV, 160 MVA X-mer – II (which was on Main Bus-II, and Bus

Bar protection scheme was in service) burst, due to which 220/132 kV, 160 MVA X-mer – II

tripped on differential relay and bus-bar protection of 220 kV Main Bus – II operated,

resulting in tripping of 220 kV Ratlam – Nagda Ckt – II & 220 kV Ratlam – Badnagar Ckt –

II & 220 kV Bus Tie which were on Main Bus – II at 220 kV Ratlam S/s. Consequently

complete 220 kV load of 220 kV Ratlam S/s shifted on 220/132/33 kV, 160 MVA X-mer – I

and due to fire (as CT Burst) in 220 kV yard, 220/132/33 kV, 160 MVA X-mer – I was Hand


Tripped resulting in failure of 132 kV supply at 220 kV Ratlam S/s, 132 kV Ratlam S/s, 132

kV Sailana S/s & 132 kV Khachrod S/s.

At the same instant i.e., at 11:05 Hrs 132 kV Malhargarh – Mandsour Ckt tripped form 132

kV Malhargarh S/s end on over current, resulting in complete failure of supply at following

S/s:-

1. 132 kV Mandsour S/s.

2. 132 kV Daloda S/s.

3. 132 kV Jaora S/s.

At the instant of above trippings there was no interruption at 132 kV Meghnagar S/s & 132

kV Jhabua S/s as power was supplied by 132 kV Badnagar – Ratlam Ckt. which remained in

charged condition.

Before the occurrence at 220 kV S/s Ratlam all the 220 kV and 132 kV feeders were in

charged condition and normally loaded. 132 kV Meghnagar S/s is fed through 132 kV

Badnagar – Ratlam Ckt which was Bipassed via 132 kV Auxillary Bus at 220 kV Ratlam S/s.

The tripped elements were restored by 11:35 Hrs. Total Load Loss was approx. 264 MW.

Committee observed that the tripping was in order.

2.3.15 : Occurence on 29.04.13 at 220kV Nagda S/S

MPPTCL representative stated that at 22:00hrs on 29.04.2013 “Y” – Phase Line CT of 132 kV Railway Traction – I burst at 220 kV S/s Nagda, resulting in tripping of following feeders/transformers:-

1. 220/132 kV, 160 MVA X-mer – I & II at 220 kV S/s Nagda. 2. 220/132 kV, 125 MVA BHEL X-mer – I at 220 kV S/s Nagda. 3. 132 kV Nagda – Khachrod Ckt. – from 132 kV S/s Khachrod end. 4. 132 kV Nagda – Ratadiya Ckt. – from 132 kV S/s Ratadiya end.

132 kV Nagda – Alot, 132 kV Nagda – Mahidpur Ckt. – I & II, 132 kV Nagda – Grasim(Industrial Feeder) and 132 kV Railway Traction – II at 220 kV S/s Nagda did not trip and was Hand Tripped after supply failure. Due to the above tripping 132 kV supply failed at 220 kV S/s Nagda, 132 kV S/s Mahidpur, 132kV S/s Zarda, 132 kV S/s Alot. At the instant of above occurrence there was no tripping on 220 kV side at 220 kV S/s Nagda and 33kV Supply at 220 kV S/s Nagda was available via 220/33 kV, 100 MVA X-mer, hence no loss of 33 kV load at 220 kV S/s Nagda. Supply at 132 kV S/s Khachrod was available via 220 kV S/s Ratlam & supply 132 kV S/s Ratadiya was available via 220 kV S/s Ujjain.


Committee observed that tripping was in order. It was recommended MPPTCL should

pursue suitable/timely preventive and routine maintenace of CTs.

2.3.16 : Occurence on 21.03.13 at 220kV Pandhurna S/S

MPPTCL representative stated that at 22:10hrs on 21.03.13, 132 kV ‘C’ – Phase CT of

132/33 kV, 20 MVA EMCO X-mer - II burst at 220 kV S/s Pandhurna. Due to above tripping

220/132 kV, 160 MVA, CGL MAKE X-mer tripped from 132 kV side at 220 kV S/s

Pandhurna, hence 132 kV supply failed at 220 kV S/s Pandurna. Consequently total 132 kV

supply failed at following S/s’s:-

1. 132 kV S/s Borgaon.

2. 132 kV S/s Multai.

3. 132 kV S/s Pandurna.

Before the occurrence, at 220 kV S/s Pandhurna all the 220 kV & 132 kV feeders were in

charged condition and normally loaded. 132 kV Boregaon – Chhindwara link was open from

220 kV S/s Chhindwara end & 132 kV Multai – Betul link was open from 220 kV S/s Betul

end. Therefore 132 kV S/s Multai & 132 kV S/s Boregaon were being fed radially through

220 kV S/s Pandurna.

Supply was resumed by charging 132 kV Multai – Betul Ckt. at 22:13 Hrs. Supply was

resumed by charging 132 kV Boregaon – Chhindwara Ckt. at 22:18 Hrs. Subsequently

132/33 kV, 40 MVA X-mer at 132 kV S/s Boregaon was charged at 22:25 Hrs. 132 kV

Supply at 220 kV S/s Pandurna was resumed by charging 132 kV Pandurna – Boregaon Ckt.

at 22.20 Hrs. Subsequently 132 kV Railway Traction – I & II at 220 kV S/s Pandurna was

charged at 22:20 Hrs. And 220/132 kV, 160 MVA X-mer was charged at 23:07 Hrs.

respectively.

Committee observed that tripping was in order. It was recommended MPPTCL should

pursue suitable/timely preventive and routine maintenace of CTs.

2.3.17 : Occurrence on 26.04.13at 220kV Barwaha S/S

MPPTCL representative stated that at 22:35hrs on 26.04.13, 220 kV ‘B’ – Phase CT of

220 kV Barwaha – Indore Ckt – I failed at 220 kV S/s Barwaha end. However, this feeder

tripped immediately from both ends, but due to flashover caused by failed CT to nearby

bays, this event converted in to bus fault, consequently all the 220 kV feeders connected to

220 kV bus Barwaha tripped from remote end in Zone II protection of DPRs. There were


no interruptions due to these trippings, and load was manageable from 132 kV systems,

i.e., isolated well in time from the faulty network. The replacement of defective bus bar

protection scheme at 220 kV S/s Barwaha is already in process.

Due to above occurrences at Barwaha, 220 kV Omkareshwar – Barwaha and 220 kV

Omkareshwar – Barwaha tap Nimrani feeders were tripped in Zone II from Omkareshwar

(OSP) end.

But simultaneously, all the generators running at OSP i.e., Machine no. 2, 3, 4, 5 also

tripped on phase over current protection of GTs.

At the instant of above occurrence (i.e., on 26.04.2013 at 22:35 Hrs.) following 220 kV

feeders/ transformers were tripped:-

1. 220 kV Barwaha – Indore Ckt. – II – tripped from 400 kV S/s Indore end.

2. 220 kV Barwaha – Handia Ckt. – tripped from 220 kV S/s Handia end.

3. 220 kV Barwaha – Itarsi Ckt. – tripped from 220 kV S/s Itarsi end.

4. 220 kV Barwaha – Omkareshwar Ckt. – tripped from OSP end.

5. 220 kV Omkareshwar – Barwaha tap Nimrani – tripped from Nimrani and

Omkareshwar end.

6. 220/132 kV, 160 MVA X-mer at 220 kV S/s Barwaha – tripped from L.V side.

7. 220/132 kV, 3 x 40 MVA X-mer at 220 kV S/s Barwaha – tripped from both sides.

There was a total generation loss of approx. 198MW,

Supply was restored by 23:59 Hrs. The 220/132 kV, 3 x 40 MVA X-mer at 220 kV S/s

Barwaha – at 19:35 Hrs. on 27.04.2013. OSP Machines were taken on bar by 22:46 Hrs.

Committee observed that the tripping of lines from remote ends due to faulty BB

protection scheme was in order. MPPTCL was requested to repair/replace the faulty

BB protection scheme at the earliest. Further the tripping of Unit nos. 2, 3, 4, 5 on

phase over current protection was undesirable and therefore MPPTCL/MPPGCL

should review the settings/ test the O/C relays.

MPPTCL representative informed that replacement of the faulty bus bar protection

scheme is under progress.

2.3.18 : Occurence on 27.04.13 at 220kV Barwaha S/S

MPPTCL representative stated that at 10:20 hrs on 27.04.2013, 220 kV Barwaha – Handia

feeder tripped from both ends on a transient fault, generator no. – 7 at OSP tripped on

phase over current protection of GT. Omkareshwar Power Station (OSP) Unit no. – 7, 8


were on Bar prior to occurrence.

The above tripping occurred due to bursting of ‘B’ – Phase CT of 220 kV Barwaha –

Indore Ckt. – I and due to the absence of carrier aid & auto reclosing facility at 220 kV S/s

Barwaha, all the units under operation at OSP also tripped.

In 116th PCC meeting of WRPC held at Nagpur on 30 – 31 JAN 2013, such trippings at

OSP, till DEC 2012, were discussed and the committee recorded following comment for

OSP in the MOM of meeting; “Committee observed that tripping of generating units on

over current protection was undesirable since the fault cleared within Zone I timings. The

over current relays of the GTs should be tested and the settings should be checked for

coordination.”

There was a total generation loss of approx. 52MW.

Unit no. - 6 was synchronized at 10:25 Hrs. and 220 kV Barwaha – Handia feeder was

charged at 11:02 Hrs on 27.04.2013.

The observations of the Committee were as recorded at Item 2.3.17.

2.3.19 : Occurence on 28.04.13 at 220kV Dewas S/S

MPPTCL representative stated that at around 00:25 Hrs. ‘R’ – Phase CT of 132 kV Bus-

Coupler burst at Dewas, resulting in tripping of 132 kV Dewas – BNP I &II, 132 kV

Dewas – MSP from both end, 220/132 kV, 160MVA X-mer – I& II and 132kV Dewas –

Chapda Ckt. – from 132 kV S/s Chapda end, hence 132 kV supply failed at 220 kV S/s

Dewas and resulted in total supply failure at 132 kV S/s Chapda, 132 kV S/s BNP Dewas

and 132 kV S/s MSP Dewas.

No tripping occurred on 220 kV side at 220 kV S/s Dewas.

Prior to the fault 132 kV Dewas – Sonkatch Ckt. was open from 132 kV S/s Sonkatch end,

132 kV MSP Dewas – Indore SZ Ckt. was open from 132 kV S/s MSP Dewas end and 132

kV BNP Dewas – Ujjain Ckt. was open from 220 kV S/s Ujjian end for load management.

132 kV Chapda was feeding through bus-coupler breaker due to outage of its main breaker

at 220 kV S/s Dewas end. Remaining 220 kV & 132 kV feeders at 220 kV S/s Dewas were

in charged condition and normally loaded.

132 kV supply was restored at 220 kV S/s Dewas from 220 kV supplies available at 220

kV S/s Dewas by charging 220/132kV, 160 MVA X-mer – I at 00:35 Hrs. Supply restored

at 132 kV S/s BNP Dewas by 00:32 Hrs. by charging 132 kV BNP Dewas – Ujjain Ckt

from 220 kV S/s Ujjain

Committtee observed that the trippings were in order.


2.3.20 : Occurence on 28.02.13 at 220kV Malanpur S/S

MPPTCL representative stated that at 02:14hrs on 28.02.13, 220 kV Malanpur – Gwalior

(PGCIL) Ckt – II from both end & at 03:45 Hrs 220 kV Malanpur – Auriya Ckt tripped from

both ends with following indications:-

1. 220 kV Malanpur – Gwalior (PGCIL) Ckt – II

At 220 Malanpur S/s end – on E/F relay.

At 765 Gwalior (PGCIL) S/s end – on Z-II, 29.1Km, R, G & E/F.

2. 220 kV Malanpur – Auriya Ckt

At 220 kV Malanpur S/s end – on Z-I, 119.9 Km, A, G.

At Auraiya (U.P) S/s end – on Z-I, 25.55 Km, R, G.

At 03:50 Hrs, 220 kV Malanpur – Gwalior (PGCIL) Ckt – II was charged from 220 kV

Malanpur end, at the same time 220 kV Malanpur – Gwalior (PGCIL) Ckt – I tripped from

765 kV Gwalior (PGCIL) end on Z-II, 44.5 Km, R, G indication and 220 kV Malanpur –

Mehgaon Ckt tripped from 220 kV Mehgaon S/s end, hence total supply at 220 kV Malanpur

S/s, 132 Ambha S/s and 132 kV Morar S/s.

The tripping occurred due to failure of string of 220 kV Malanpur – Gwalior (PGCIL) Ckt –

II at location no: 84 and snapping of conductor. On testing/checking of DPR at 220 kV

Malanpur S/s, it was found defective and was replaced.

Supply was resumed by 20:51 Hrs.

Committee observed that operation of E/F relay at Malanpur and operation of DPR in

Zone-II from Gwalior end of 220kV Malanpur-Gwalior line on line fault was

undesirable. Further tripping of 220kV Malanpur-Auriya from both ends in Z-I was

also undesirable.

2.3.21 : Occurence on 01.03.13 at 220kV Malanpur S/S

MPPTCL representative stated that at 00:11hrs on 01.03.2013, 220 kV Malanpur – Gwalior

(PGCIL) Ckt – I & II tripped from 765 kV S/s Gwalior (PGCIL) end & at 00:12 Hrs 132 kV

Malanpur – Morar Ckt (Radial Feeder) tripped from 220 kV S/s Malanpur end as jumper of

B- phase CB to Main Isolator broke at 220 kV S/s Malanpur and same feeder tripped on “R”

& “Y”- Phase O/C & E/F indications. Subsequently following feeder/transformer tripped:-

1. 132 kV Malanpur – Mehgaon Ckt. – from 220 kV S/s Malanpur end.

2. 132/33 kV, 40 MVA X-mer at 220 S/s Malanpur – at 00:14 Hrs as its 132 kV, R –

Phase CT failed.


There was no interruption at 220 kV S/s Malanpur as its load was feed by 220 kV Malanpur –

Auriya Ckt & 220 kV Malanpur – Mehgaon Ckt. There was interruption at 132 kV S/s Morer

only.

132 kV Malanpur – Mehgaon Ckt. was charged at 01:10 Hrs. and 220 kV Malanpur –

Gwalior (PGCIL) Ckt – I & II was charged at 01:41 Hrs & 01:42 Hrs respectively.Supply at

220 kV S/s Morar was resumed by charging 132 kV Malanpur – Morar Ckt (Radial Feeder)

at 01:45 Hrs. 220/132 kV, 20 MVA X-mer at 220 kV Malanpur S/s – at 04:17 Hrs.

132 kV, R – Phase CT of 132/33 kV, 40 MVA X-mer has been replaced and transformer was

charged at 15:58 Hrs on 01.03.2013.


2.3.22 : Occurence on 30.04.13 at 400kV ISPS S/S

MPPTCL representative stated that on 30.04.2013, at ISPS Unit no: - 5 and Bus Coupler

was under outage, and during the permit all the units and feeders of ISPS was connected to

Main Bus – A and Bus Coupler was out. Unit no: – 1, 2 & 3 were On Bar.

After cancellation of permit and at the time of restoration of Unit no: – 5, 6, 7, 8 and 400

kV ISPS – Indore Ckt. – II & 400 kV ISPS – Sarni Ckt were shifted to Main Bus – B. At

around 18:20 Hrs. while closing the Unit no. – 7 to Main Bus – B, operating rod insulator

of PG – isolator of “R” – Phase was broken from the lower section (therefore it was in

non-moving condition) hence PG – isolator could not fully close. As PG – Isolator of “R”

– Phase was not fully closed sudden heavy flashing/sparking occurred and all feeders and

Units on Bar tripped. Following trippings occurred:-

1. Unit no: - 1, 2 & 3 – Tripped on – Class A relay operated, Unit over-speed 115%,

Electrical over-speed device operated.

2. 400 kV ISPS – Sarni Ckt. – tripped from ISPS end.

3. 400 kV ISPS – Indore Ckt. – II – tripped from ISPS end.

4. 400 kV ISPS – Indore Ckt. – I – tripped from 400 kV S/s Indore end.

5. 400 kV ISPS – Nagda Ckt. – tripped from 400 kV S/s Nagda end.

Initially ISPS had reported tripping on Over-voltage and report received from ISPS

forwarded to WRLDC.

Supply at ISPS was resumed by Charging the 400 kV ISPS – Nagda Ckt. at 19:20 Hrs.

Subsequently other feeders were charged by 21:27 Hrs. The 400 kV ISPS – Indore Ckt. – I

– at 09:13 Hrs on 01.05.2013. Total generation loss of approx. 323MW


Committee felt that BB protection at ISPS S/S should have operated.

2.3.23 : Occurence on 27.03.13 at 220kV Julwaniya S/S

MPPTCL representative stated that at 23:32hrs on 27.03.13, “R” – Phase CT of 132 kV

Julwaniya – Nimrani Ckt. – I burst and it damaged the “B” – Phase CT of 132 kV Julwaniya

– Nimrani Ckt. – II at 220 kV S/s Julwaniya, consequently these Ckt’s tripped from far end

with following indications occurred:-

1. 132 kV Julwaniya – Nimrani Ckt. – I .

At 220 kV S/s Julwaniya end:- Zone – I, ABC Trip, AN – Phase.

At 220 kV S/s Nimrani end:- Zone – I, ABC Trip, AN – Phase, Distance –

33.03Km.

2. 132 kV Julwaniya – Nimrani Ckt. – II .

At 220 kV S/s Julwaniya end:- Zone – I, B – Phase.

At 220 kV S/s Nimrani end:- Zone – II, R – Phase, Distance – 47.34Km.

Due to above tripping 132 kV side of 220/132 kV, 160 MVA X-mer tripped on O/C, “B” –

Phase indication consequently following feeders/transformers tripped:-

1. 132 kV Julwaniya – Barwani Ckt. – from 132 kV Barwani end.

2. 132 kV Julwaniya – Khargone Ckt. – from both ends.

The tripping of the above feeders resulted in failure of 132 kV Supply at 220 kV S/s

Julwaniya, 132 kV S/s Sendhwa & 132 kV S/s Pansmel.

All the tripped elements were restored by 00:56 Hrs.

“R” – Phase CT of 132 kV Julwaniya – Nimrani Ckt. – I was replaced and the line was

charged at 19:35 Hrs. on 29.032013. “B” – Phase CT of 132 kV Julwaniya – Nimrani Ckt. –

II was also replaced and feeder charged at 09:30 Hrs. at 02.04.2013.

Committee felt that the trippings were in order.

2.3.24 : Occurence on 05.04.13 at 220kV Shivpuri S/S

MPPTCL representative stated that at 11:20hrs on 05.04.2013, 220 kV Shivpuri – Bina

(PGCIL) Ckt. tripped from 220 kV S/s Shivpuri end due to transient fault on Phase – ABC,

Zone – 1 and at 11:40 220 kV Shivpuri – Bina (MPPTCL)Ckt. tripped from 220 kV S/s

Shivpuri end on L – 123, Zone – 1, Distance – 10Km, VT Fuse Fail indications, hence total

220 kV supply at 220 kV S/s Shivpur & 220 kV S/s Sabalgarh failed but 132 kV Supply at

220 kV S/s Shivpuri was available via 132 kV Interconnector – I & II. Consequently

interruption occurred at following S/s’s:-


1. 220 kV S/s Sabalgarh.

2. 132 kV S/s Sheopur.

3. 132 kV S/s Vijaypur.

4. 132 kV S/s Motizeel.

5. 132 kV S/s Jora.

Before the occurrence at 220 kV S/s Shivpuri all the 220 kV & 132 kV feeders were in

charged condition and normally loaded. 132 kV Motijheel – Tigra Ckt., 132 kV Motijheel –

Mahalgaon Ckt., 132 kV Motijheel – Banmore Ckt. – I & II were open for Load

Management. Therefore 132 kV S/s Motijheel & 132 kV S/s Jora was feed through 220 kV

S/s Sabalgarh.

Supply at 132 kV S/s Motijheel was resumed by charging 132 kV Motijheel – Banmore Ckt.

– I & II at 11:55 Hrs.The 220 kV supply at 220 kV Shivpuri S/s & 220 kV S/s Sabalgarh was

resumed by 12:40 Hrs.

Committee felt that the trippings were in order.

2.3.25 : Occurrence on 07.04.13 at 220kV Shivpuri S/S

MPPTCL representative stated that at 14:10hrs on 07.04.13, 220 kV Shivpuri – Bina (PGCIL) Ckt. tripped from both end due to transient fault, hence total 220 kV supply at 220 kV S/s Shivpur & 220 kV S/s Sabalgarh failed but 132 kV Supply at 220 kV S/s Shivpuri was available through 132 kV Interconnector – I & II via 132 kV S/s Pichhore. Consequently interruption occurred at following S/s’s:-

1. 220 kV S/s Sabalgarh. 2. 132 kV S/s Sheopur. 3. 132 kV S/s Vijaypur. 4. 132 kV S/s Motizeel. 5. 132 kV S/s Jora.

Before the occurrence, 220 kV Shivpuri – Bina (MPPTCL) Ckt., at 220 kV S/s Shivpuri was under shutdown for DPR relay testing work fom 14:01 Hrs. on 07.04.2013, remaining all the 220 kV & 132 kV feeders were in charged condition and normally loaded. 132 kV Motijheel – Tigra Ckt., 132 kV Motijheel – Mahalgaon Ckt., 132 kV Motijheel – Banmore Ckt. – I & II were open for Load Management. Therefore 132 kV S/s Motijheel & 132 kV S/s Jora was feed through 220 kV S/s Sabalgarh. Supply at 132 kV S/s Motijheel was resumed at 14:20 Hrs subsequently 132 kV Supply at 220 kV S/s Sabalgarh was resumed by 14:42 Hrs. 220 kV Supply at 220 kV S/s Shivpuri & 220 kV S/s Sabalgarh was resumed by 17:13Hrs.



2.4: System disturbances in MSETCL/MSPGCL system.

2.4.1 : Occurrence on 03.03.2013 at 400kV Girwali sub-station.

MSETCL representative stated that on 03.03.2013 at 18:05Hrs; C-Phase breaker pole of

400kV PRL-CHD-III, at 400kV Girwali S/S got burst and created a bus fault. The

disturbance occurred while withdrawing 400kV PRL-CHD-III from service for controlling

over voltage. All the lines/elements connected to Bus-I tripped on operation of Zone-I (Bus-I)

Numerical Bus bar scheme make ER_Type_CSC-150.

Due to tripping of ICT1 & ICT2, all the load was fed by ICT3 only. Load trimming scheme

of ICT 3 operated thereby tripping radial loads at Girwali and Parli.

The Parli – Chandrapur 3 circuit breaker was hand tripped at Chandrapur end. The circuit

breaker of this line at Girwali (Parli) end tripped on receipt of direct carrier signal. The event

records show that the first pole to clear was C pole. The bus voltage at this time was more

than 430 kV. With opening of this breaker a restrike developed across the breaker and this

phenomenon continued for @ 7 seconds. During this time 400 kV Parli – Chandrapur 2

tripped at Girwali (Parli) due to over voltage. There was no direct carrier sent from Girwali

end with this overvoltage operation. This was due to failure of 86ROV relay trip coil. The

relay was replaced subsequently. Over voltage protection of Parli – Chandrapur 3 operated

twice during the continued arcing at Chandrapur end. Subsequent failure of C pole breaker

and dislocation of IPS tube created a bus fault which was correctly and selectively cleared by

the busbar protection at Girwali (Parli).

Details of breaker: BHEL make Manufacturing Year: 1987

Commissioning date: 26-03-1991

Last overhauling of breaker: 20-06-2012

Last breaker timing results: 20-06-2012 Results were in order

Last DCRM: 20-06-2012 Results were in order

There were no marks of any arcing on main contacts of breaker. Arcing marks were present

on C pole bus side main contact end connecting portion and corona ring. The marks present

on damaged porcelain and connecting points of this pole suggest that there was sustained

arcing across this pole. This sustained arcing may have resulted in restrike of recovery

voltage appearing across the first pole to clear which was C pole in this case. This line is 373


KM long. There was no reactor connected at Chandrapur end. 50 MVAR reactor at Girwali

was in service.

All the elements were restored by 19:44 hrs of 03.03.2012.

Committee felt that due to persisting over voltage while opening of the C-Pole of the

breaker (i.e breaking of capacitive current, since the line length is @400kms.) restriking

voltage developed across the breaker resulted in bursting of the C-Pole breaker.

2.4.2 : Occurrence on 01.02.2013 at 220kV S/S New GCR Parli.

MSETCL representative stated that on 01.02.2013 at 11:33Hrs, bus bar protection operated at

220kV New GCR Substation. Before this occurrence, at 11:01Hrs, 220kVNew TPS -Nanded-

II circuit tripped on DPR from 220kV New GCR end and on Carrier receipt from 220kV

Nanded end.

Since the 220kV New TPS – Nanded circuit remained charged from Nanded end, the circuit

breaker at New TPS end was closed at 11:33 Hrs. The bus bar protection of Main Bus-II at

New TPS operated with closing of this circuit breaker resulting into tripping of all the lines

and generator connected to Main bus 2. The 220kV Busbar Protection is of make : AREVA

Model: P741.

Fault currents recorded : Ia= 2.634kA Ib=553.1A Ic=435.9A In=2.287kA

All the tripped elements were restored by 01.02.2013 @23:22Hrs

Based on the digital fault records available from Busbar protection relay peripheral units at

New TPS Parli and records from distance protection relays at Nanded and New TPS ends

following was concluded;

At 11:01 Hrs. the New TPS – Nanded ckt2 tripped at NewTPS end and did not trip at Nanded

end. The tripping was due to open jumper of R phase which was causing fault feed only from

New TPS end and no feed from Nanded end. The New TPS end breaker opened correctly.

The open jumper at location number 240 was touching Y phase conductor on New TPS side.

The line remained charged from Nanded end. This effectively brought RY system voltage

across the breaker of this line at NewTPS end while the breaker was open. Closing of this

breaker created a RY fault inside the breaker. Busbar protection saw this as end zone fault

initially and with changing of breaker position the fault became a Bus Zone -2 fault. The

operation of busbar protection for this case is in order.

Since the 220kV New TPS – Nanded circuit remained charged from Nanded end, the circuit

breaker at New TPS end was closed at 11:33 Hrs.


Committee felt that the jumper of R phase got opened from Nanded end and touched

with Y phase conductor thereby tripping the line from New TPS end, though there was

no tripping from Nanded end and the conductor remained open from Nanded end.

Even after isolation of the fault the jumper remained in contact with Y phase conductor

towards New TPS end. After closing the breaker from New TPS end, the fault virtually

got transferred to across the breaker at New TPS and translating in Bus fault.

2.4.3 : Occurrence on 14.02.2013 at 400 kV R.S. Kolhapur(Talandge).

MSETCL representative stated that the 400 kV Bus Bar protection (Both Zone-I & Zone-II)

operated on 14.02.2013 at 10:08 Hrs. due to failure of 400 kV ‘R’ph Bus-I CVT. The Zone-I

Bus Bar protection operated as a result of bursting of Bus-I, ‘R’ph CVT. Subsequently Zone-

II Bus Bar protection operated, since the smoke / fumes of bursted CVT came in vicinity of

nearby ‘R’ ph Bus-I pentagraph isolator ( 89A) of 400 kV Karad ckt-II line which was in

service through Bus-II .


2.4.4 : Occurrence on 7.02.2013 at 220 kV Miraj S/stn..

MSETCL representative stated that on 07.02.2013 at 15:20 hrs., 110 kV Bus bar protection

operated at 220 kV Miraj S/stn. due to heavy fault on 33 kV Digraj bay isolator at 110 kV

Vishrambag S/stn.

The existing busbar scheme (EE Make Type CAG) is commissioned in 1978. Post occurrence

the Scheme was tested for Pick up at 0.8A & found in order. However, mech. problem in the

contact of the Main feature B phase element was observed and the same was replaced. DR of

Back up relay of ICT I, II & III confirmed that they have picked up at the time of occurrence.

The system was restored at 15:39 hrs on 07.02.2013. The load affected was

201 MW for 19 min.

Committee observed that operation of BB protection for through fault was not desirable

and suggested to review the bias setting of BB protection.

2.4.5 : Occurrence on 20.01.2013 at 220kV Lonikand S/S.:

MSETCL representative stated that on 20.01.2013 at 14 :46 Hrs., at 220 kV Lonand S/stn. all

220 kV feeders & equipments tripped due to initiation of LBB from 220 kV Baramati feeder

panel Distance Protection Relay (ABB REL 670). All 220 kV feeder, equipments & 220 kV

Bus tripped.


There was no fault on line & hence circuit breaker at Baramati end did not trip. The LBB

initiation was due to malfunction of newly commissioned ABB REL 670 relay.

This panel was newly commissioned in presence of M/S. ABB representative on Dt.

13.12.2012 & relays were configured by M/S. ABB representative. M/S. ABB representative

visited the substation on Dt. 22.01.13 declared that the relay was faulty & needs to be

repaired at factory. Hence it was sent for repairs. Feedback from M/s ABB is awaited.

The load affected was 153 MW for 19 minutes & whole area under Lonand S/S was affected.

Committee felt that the faulty LBB relay should be replaced.

2.4.6 : Occurrence on 12.03.2013 at 220kV R.S.New Koyna S/S.:

MSETCL representative stated that tripping of 220 kV Bus I & II took place at 15:53 hrs. on

12.03.2013 at 400 kV R.S. New Koyna while carrying out wiring for differential protection relay

MICOM P663 for DR purpose by AREVA service engineer. The tripping of 220kV Bus I & II

took place as a result of extension of DC +ve to LBB trip Bus from ICT-I LV side relay panel.

The Area affected in this occurrence is 8MW for 32minutes & system is restored at 17 :07hrs.

Committee felt that human error would have been avoided.

2.4.7 : Occurrence on 06.01.2013 at 220kV Apta S/S.:

MSETCL representative stated that on 06/01/2013 @ 07:38Hrs , 220kV Apta-Uran-2, B

phase Coupling capacitor burst at Apta end resulting in operation of distance protection of

the line and a simultaneous operation of Bus bar protection (Make SIFANG CSC) Zone B

Differential Trip, R phase of Bus section- II, tripping all feeders/equipments connected to the

220kV Bus section II . The 220 kV Bus section-I remained healthy.

At 07:33:16:2887 hrs : Single phase (B phase) to ground fault occurred due to bursting of

Coupling Capacitor of the 220kV Apta Uran-2 line at Apta end and the same was cleared by

line distance protection from both the ends . At Apta end, being A/R in service, the B pole

tripped instantly & reclosed after dead time of 1 sec. At Uran end, the fault was cleared in

Zone-I with definite 3 phase trip as A/R is out being generating end.

At 07:33:17:3459 hrs. (10572 msec.): At Apta end, due to permanent nature of fault, the line

reclosed & tripped again instantly on SOTF (TOR) with definite 3 Ph trip & A/R L/O. The

system was normal for a period of next 659 msec

At 07: 33:18:1294 hrs. (18407 msec): The Zone II Bus Bar operated on R ph. fault. The Bus

fault was created due to post fault swinging of CC jumper touching the R phase of Main Bus.

The physical inspection at site confirms that the Coupling Capacitor drop jumper was


hanging along with the CC cap. Sparking marks were observed on CC cap and Main Bus R

phase conductor.

The Jumper length of the CC is sufficiently large to create above condition as the Bus section

II yard (Roadside) is at lower height than the Bus section I yard (Hill side) resulting in

increasing the length of LA/CC drop Jumpers.

i) The Bus Bar protection of section II operated correctly & tripped all the

feeders & equipments connected to Bus II .

ii) Details of CC:- Make WS Industries Ltd

Mfg. Year/ Commissioning Year – 1990

Last date of Maint: 18/12/2012

Top to Bottom Stack IR Values on 18/12/2012 by 5 kV Megger

= 35 Gohm

iii) The CC failed due to primary insulation failure being old age which sustained

high voltage & switching surges during the service life. Also, the system is

experiencing high voltage during these days. The Bus voltage recorded was

around 235 kV prior to the occurrence.

No 100 /22 kV load is affected due to occurrence. After isolation of faulty CC, Bus Section

– II was charged through 220kV Tambati feeder at 08:16 hrs on 06.01.2013 & normalcy

restored by 06.01.2013 at 08:16 Hrs.


2.4.8: Occurrence on 08.01.2013 at 220kV Airoli Knowledge Park S/S :

MSETCL representative stated that on 08.01.2013 at 02:55hrs, the 220kV B ph PT in respect

of 220kV Bus-Section – I burst & resulted into operation of Bus-bar protection (Make ABB,

REB500) at 220kV Airoli Knowledge Park s/s.

The 220kV B – phase bus-sectionalizer – I PT burst & caught fire at 220kV AKP s/s. This

resulted into operation of 220kV Bus-bar protection (REB 500, ABB make). All the

equipments connected to 220kV Bus-section – I tripped on operation of bus-bar protection.

Simultaneously B ph Wave Trap of 220kV AKP – Kalwa line uncoiled at 220kV Kalwa s/s.

The line differential protection provided on this line operated at both ends. The uncoiling of

220kV Wave Trap at 220kV Kalwa s/s might be because of heavy fault current i.e. 35kA

during the PT failure. The currents recorded were Ir = 198A, Iy= 210A, Ib = 35.077kA, In =

35.47kA.


The wave trap was replaced by new one and 220kV Kalwa – AKP line is taken into service

on 08.01.2013 at 18:26hrs.

Sub-sequent failure of PT at 220kV AKP s/s, the 50MVA, 220/22kV TF No. I was taken into

service through 220kV TBC. The bursting of 220kV B ph PT of SCT make

(Sr.No.2008/2302, YOM: 2008, DOC: 2010) might have occurred due to primary insulation

failure. The 220kV bus PT was replaced by spare PT of “High Voltage – Trans” make &

taken into service on 09.01.2013 at 01:26hrs.

The load affected at 220kV AKP s/s during the occurrence was about 20MW.

All the tripped elements were restored by 18:26hrs on 08.01.2013


2.4.9 : Occurrence on 13.03.2013 at 220kV Sonkhar s/s.

MSETCL representative stated that on 13.03.2013 at 00:36hrs 220kV R ph Bus Section – II

PT burst at 220kV Sonkhar s/s resulted in total power failure at 220kV Sonkhar and Nerul

s/s.

At 00:36hrs, the 220kV R ph bus section – II PT burst & caught fire at 220kV Sonkhar s/s.

The 220kV bus bar protection REB500, ABB make was kept out of service since

commissioning due to communication problem. The issue of taking the bus-bar protection

scheme into service was taken up with M/s ABB. However M/s ABB has failed to attend this

problem.

Subsequently the 220kV R ph PT fault wass cleared by remote end trippings. The 220kV

Sonkhar – Nerul Line tripped at 220kV Nerul end in R-E, Zone –I. The Auto – Reclose is

provided / commissioned on this line, hence operated for R-E, Zone – I fault correctly &

subsequently tripped on SOTF due to permanent PT failure fault at Sonkhar. Further, the

overreaching of distance relay at Nerul end was due to mismatch of line distance (set to 6

km). However during this fault the relay has recorded a distance of 4.59km.

The 220kV Nerul – Kalwa line also tripped at 220kV Kalwa end on R-Y-E, Zone – I. At the

first instant of A/R of 220kV Sonkhar – Nerul line, the distance relay at Kalwa end only

picked up on R-E with fault distance of 19.11km. Subsequently after A/R attempt failure, the

distance relay operated in R-Y-E, Zone – I, fault distance of 34.5km & tripped the line at

Kalwa end. The phase to phase i.e. R Y phase involvement was due to fumes & flame of R ph

PT coming in induction zone of adjacent Y ph PT.

The 220kV Kalwa- Kharghar line is terminated/reoriented to 220kV Nerul s/s on07.03.2013.

The overreaching of distance protection at Kalwa for ph – ph fault may be due to incorrect


line length and conductor parameters in a view of reorientation of the line.

The failure & bursting of 220kV R ph PT SCT make (Sr. No. 82, YOM: 2008, DOC:

31.03.2009) might have occurred due to primary insulation failure.

The 220kV PT was replaced by spare Meheru make PT on 13.03.2013 at 08:05hrs.

1. The M/s ABB Engineer visited the 220kV Sonkhar s/s on dtd. 27.04.2013 for

rectification & taking bus bar scheme in to service. After attending communication

problem & testing bus-bar scheme is taken into service on 27.04.2013.

2. The distance relay setting in respect of 220kV Sonkhar-Nerul line was revised to

4.59kM as per relay record.

The total load affected at 220kV Sonkhar & Nerul s/s is about 34MW & 40MW

respectively. All the tripped elements were restored by 13.03.2013 at 18:05hrs

Committee observed that tripping of elements from remote ends in absence of BB

protection was in order and expressed that the BB protection be put into service at the

earliest.

2.4.10 : Occurrence on 26.03.2013 at 400/220/100/22 kV Padghe S/stn.

MSETCL representative stated that on 26.03.2013 at 18:08 Hrs, 220 kV R-phase CT of 3 x

200 MVA, 400/220 kV ICT IV at Padghe s/s busted & caught fire at Padghe substation

resulting in to tripping of all the 220kV feeders & equipments connected to 220kV Main-

Bus-II (B Bus ) on operation of Bus bar protection (ABB RADSS). This resulted into loss of

load to the tune of 334 MW on 100 kV /22 kV level. The 3x600 MVA, 400/220 kV ICT IV

tripped on Differential Prot. (86 A& B optd). The 200 MVA, 220/100 kV ICT III tripped

from LV side on operation of B/U O/C since entire 100 kV load (254 MW) was shifted on

ICT-III.

Normally ICT 1&2 are in Parallel & feeds the 100 kV Bus-I (270 MVA) while ICT 3&4 are

in parallel & feeds the 100 kV Bus-II (180 MVA). The 100 kV B/S Breaker is kept off.

However, at the instant, all the ICTs II,III & IV were running in parallel with B/S Breaker

ON, since ICT I was out for isolator replacement work.

The load trimming scheme provided for 220/100 kV ICT I & II only trims 60-65% of 100 kV

loads on Bus –I, in the event of Bus –I & II are separate.

The failed 220kV R-phase CT of LAMCO, Hyderabad make (Sr. No CF-329; YOM-2011)

newly commissioned on 03.11.2012. The capacitance & tan delta measurement at the time of

commissioning are as below. The CT failed under guarantee period.


Phase Make/ Sr. No./YOM C& tan delta at the time of

commissioning

C& tan delta as

on 27/03/2013

R LAMCO / CF-

329/2011 529.43 pf ; 0.0022 Failed

Y LAMCO/ CF-

322/2011 535.46pf ; 0.0031 536.9 pf; 0.0025

B ITC. /3034-36/ -2012 421.29 pf ; 0.0038 424.06 pf ; 0.0038

After isolation of faulty CT & extinguishing of fire, the 220kV Bus-II was charged through

bus coupler at 18:27 hrs. & normalcy restored by 18:27hrs of 26.03.2013.

After replacement of failed R-phase CT by new LAMCO make CT, Sr. No., CF 261, YOM

2011 (Capacitance 540.50 pf,; Tan Delta=0.0040) & damaged CT control cables ,the ICT IV

was taken into service at 13.00 hrs on 27/03/2013.


2.4.11 : Occurrence on 06.01.2013 at 400 kV Khadka S/S.

MSETCL representative stated that on dt. 6.1.13 at 21:25 hrs , B phase CT of 400 kV

Deepnagar ckt I got burst and caught fire at 400 kV Khadka S/S. Initially the fault developed

as a arcing fault on line side of CT, since the distance protection relay startup was indicated,

but the failure of CT resulted in Bus fault and BUS BAR protection operated. This fault was

seen in zone II by remote end of 400 kV feeders & same tripped on distance protection zone

II.

Bus arrangement before occurrence:-

BUS -1 BUS-2

1. 400 kV Koradi

2. 400 kV Babhaleshwar

3. 400/132 kV, 200 MVA ICT-1

4. 400 kV Bus Reactor (was charged From Bus-1

through TBC)

5. 400kV Deepnagar-I

1. 400 kV AKOLA

2. 400/132 kV, 200 MVA,

ICT-2

3. 400/220 kV, 3x105MVA

ICT-3


The 400 kV Bus Coupler was ON. The 400 kV Aurangabad bay was OFF due to system

constraints. (Bus-2 isolator and line was closed i.e. ready for charging as per LD

instructions). The 400 kV Khadka Deepnagar-2 ckt. was in off condition due to system

constraints. (Bus-2 isolator and line was closed i.e. ready for charging as per LD

instructions). The 400/220 kV, 105 MVA Spare ICT (connected to Bus-2 Y PH) CB was

OFF (Due to problem in CB).

The B phase 400 kV CT (Areva make) of 400 kV Khadka-Deepnagar ckt-I got burst. The

failure of CT resulted in bus fault and BUS BAR protection operated in about 474 ms. This

fault was also sensed from the remote ends of 400 kV Koradi, BBLR, D’nagar & Akola

feeders & these tripped on Dist. Protection Z 2. The 400 kV CBs of 400 kV Bus 1 tripped on

bus bar protection including bus coupler.

At 400 kV D’nagar S/S due to voltage dip GT4 tripped on Class A protection LBT 409MW.

Earlier testing result:

Details of the Failed CT are

Make AREVA

VOLTAGE LEVEL 420 kV

Serial Number 200811152

Tan Delta 0.171 %

Capacitance 1099 pF

I.R. Value 598 G Ohm

Date of Commission 22.10.2012

Committee observed that there was a delayed operation of the BB protection due to

evolving (arcing) fault.

2.4.12 : Occurrence on 08.04.2013 at 400kV Dhule

MSETCL representative stated that on 08.04.2013 outage was proposed on 400/220 kV

315MVA ICT-II for HV side breaker overhauling. Accordingly operation was carried out by

operating staff to transfer the ICT on TBC. During the operation of 400kV TBC for

400/220kV ICT II occurrence took place due to manual error. The ICT-I, II and feeder

connected to bus –I and bus II tripped at remote end at 12:15 hrs.


The operations to transfer the ICT II on TBC were being carried out by operating staff. The

TBC was charged through Bus II. The operation of the TBC was complete. But during the

opening of line isolator D, by mistake R-phase earth isolator was operated and it came into

the vicinity of the induction zone and sparking observed, immediately earth isolator was

opened. The location of the fault was under the bus bar zone but due to arcing fault and

current not sufficient to operate bus bar protection, the ICT I, II tripped on back up protection

and 400kV lines connected to bus II tripped at 12:15 hrs i.e. Khandwa-I on R-E phase fault at

remote end and SSNNL II on overvoltage stage II. Since the bus coupler was on, the 400kV

feeders i.e. 400kV khandwa II also sensed the fault and tripped on R phase in zone II at

remote end. The BBLR-Dhule II at BBLR end auto reclosed successfully.

To confirm damage to ICT I and II, the tan delta of bushing was taken and results found in

order. From the DRs of relay of ICT I and II, the time of operation of fault was nearly 550 to

600ms. The fault current recorded was 3I0=1.07A in ICT-II LV side relay and 3I0=0.77A in

ICT-I LV side relay. The time required operating the relay of 500MVA, ICT III as per setting

was more than around 900 to 1000ms for these fault currents.

Committee felt the human error would have been avoided.

2.4.13 : Occurrence on 24.04.2013 at 400 kV Babhaleshwar

MSETCL representative stated that at 400kV BBLR s/s, on 24.04.2013 at 17.38 Hrs, the

vertical R-phase string insulator of 220 kV Alephata Line bay’s dropdown jumper between

29A & 29B isolators got burst and flash over took place with gantry and resulted into

operation of 220 kV zone 1 bus bar protection.

Flash over took place between vertical R-phase string insulator 220 kV Alephata Line bay’s

dropdown jumper between 29A & 29B isolators and gantry, resulting in operation of zone-1

bus fault. All the 220kV feeders connected to bus I tripped and fault was isolated. The PID

testing of 220kV insulator disc carried out on 21.011.2012 and 24.11.2012 and results found

were in order. But the PID of same strings could not be done due to clearance problem.

The 220 kV Lines on bus 1 tripped at 400 kV BBLR end only and remained charged from

remote end.

The fault was isolated by opening 220 kV Alephata Line & bus isolators and Bus 1 was

restored by 18:20hrs of 24.04.2013, except Alephata line bay.



2.4.14 : Occurrence on 02.05.2013 at 220 kV GCR Eklahare S/S.

MSETCL representative stated that on 02.05.2013 at 00:28 Hrs, the R-phase CT of 220kV

Bus section II at 220kV GCR S/s got burst & fall on ground causing operation of 220 kV Bus

Bar Protection Zone A and Zone B. 220kV BBLR-II Hand tripped at 00:40 hrs at EKL GCR

end and hence Generation U5 tripped on overfluxing.

Equipment Failure:

Make:- SCT

Sr.No.- 2010/83

Ratio:- 2400-1200/1-1-1-1-1A

Dt. Of comm.:- 13/12/12 ( C =437.74pF & Tan Delta = 0.287%)

Last Tan Delta Results On dtd. 12/01/13 :- C=428.9pF & Tan Delta =0.725%

The R-phase CT of 220kV Bus section II at 220kV GCR S/s got burst & fell down on ground

causing operation of 220 kV Bus Bar Protection Zone A and Zone B. Bus bar protection

operated correctly and 220kV lines and ICT connected to Zone A and Zone B were tripped

correctly. The burst CT had high tan delta value and hence the cause of failure of CT is

insulation failure.

The zone A and zone B operated and fault was isolated completely. There was total

generation loss of 470MW. The generation unit-3 and generation unit-4 were in Zone A and

Zone B and tripped on bus bar protection. However the generation unit-5 was in Zone C and

it could have saved but due to the hand tripping of 220kV BBLR II line, the generation unit-

5 tripped on over fluxing at generation end. The disturbance is not recorded due to non

working of the SMS at 220kV GCR since long.

Area was not affected during the above occurrence.

Committee observed that the operation of Zone-A of the BB protection was undesirable

and therefore the same should be checked.

2.4.15 : Occurrence on 24.01.13 at 400kV Girwali Substation

MSETCL representative stated that on 24.01.2013 at 14:20Hrs, 400 kV Main Bus-II at

400kV Girwali Substation tripped due to falling of C phase quadruple conductor of Main-II

bus at C-ph of 29B PG on A & B phases of PGCIL –II IPS tubes in PGCIL-II bay. The

400kV Busbar Zone-2 tripped. The PGCIL line-I which was connected to main bus-I tripped

at PGCIL end only.


Previous thermo vision scanning of this bay was carried on 28.12.2012. The C Phase isolator

fixed contact rod connection was showing temperature of 52 degree C. There was very less

clearance between stub bus and main bus in this bay which had resulted into a bus fault on

9.07.2012. Power Grid had taken some corrective measures in this regard.


2.4.16 : Occurrence on 01.04.2013 at GMR EMCO, Maharashtra:

MSETCL representative stated that on 01.04.2013 at 17:18 Hrs, due to tripping of line 400

kV EMCO-Bhadrawati 1 & 2 in on zone 1 DPR (Y to B phase fault on both the lines) from

EMCO end, EMCO unit 1(300MW) had no outlet for evacuation leading to its tripping.

There was no tripping from the remote ends and the lines remained charged from remote

ends.

The Generation loss was around 203 MW. Unit was synchronized with the grid on 02-04-13

at 00:48 hours.


2.4.17 : Occurrence on 26.02.2013 at Goa and Kolhapur, Maharashtra:

MSETCL representative stated that from 06:00 to 07:30 Hrs. Multiple circuit tripped at

400/220 kV Kolhapur and 220 kV Kolhapur (Mudshingi) due to heavy fog. The 220 kV and

400 kV from Kolhapur to Goa tripped leading to loss of Goa load.

At 6:47 Hrs, 400 kV Kolhapur-Mapusa II ,220 kV Mumewadi –Halkarni I & II , 220 kV

Halkarni-Tillari, 200 kV Mahalaxmi-Halkarni and 220 kV Mahalaxmi-Amona tripped

leading to loss of Goa load from the Western grid:

The load loss during the event was 450 MW (As per MSETCL).

Goa load was restored by taking 400 kV Kolhapur-Mapusa II in service at 7:57 Hrs. By 15:25

Hrs all the 400 kV and 220 kV Lines were taken in service.



2.5 : Disturbances of 116th PCM which could not be analysed due to lack of

repensentation : 2.5.1 Occurrence at Nashik TPS

Nashik TPS-3 on 21.11.12

MSPGCL have intimated that Unit 3 was synchronized to grid at 05:00 hrs on 21.11.2012

after normal operations. After synchronizing the unit to grid and picking up the load to

80MW; unequal currents in three phases of generator were observed and at 5.20 hrs negative

phase sequence alarm occurred. The Negative phase sequence alarm is occurred due to the

problem persisting in 220 kV generator breaker. GCR on duty I/C was asked to shift the load

on transfer bus with permission of SLDC.

Meanwhile, Unit-3 tripped at 06:05 hrs on busbar protection due to flashover in

220kVgenerator breaker B-pole. Even though the tripping was initiated on bus bar protection

from GCR & from PCR-3 on 86 GT, the breaker poles were found in closed condition.

Breaker suspected mechanically jam in closed condition. Due to operation of busbar

protection, Stn. X'mer-S was also tripped.

Nashik TPS-3 on 8.12.12

At 01:45hrs on 8.12.12 Unit-3, Unit-4, Station Transformer No.3&4(C3, C4) tripped on

busbar protection due to bursting of Bus Section-II B-phase CT in 220kVswitch yard towards

Unit-5 side. The bus bar protection simultaneously operated, resulting in isolation of bus bar

zone-I and II. In zone-l, Unit No3 T.A set and station transformer no 3 tripped. In zone-II,

Unit No 4 T.A set and station transformer no4 tripped. Unit No 5 did not trip being in bus bar

zone-III, but due to tripping of station transformer 3 and 4, all auxiliaries charged from them

were tripped(e.g. CTLP, CT fans, SSB etc). This has resulted in Local AC failure.

Unit 5 related - Due to tripping of station transformer no 3 & 4, the CTLP's running CT fans,

all other auxiliaries on station bus were also tripped. Load reduced to minimum upto

125MW. 220kVswitchyard isolator polygon (Generator unit 4 side) in bus bar zone-I was

found also damaged. Due to isolation of bus zone-I & II, all the lines in bus zone-I & II i.e.

ICTs(1, 2, 6), 220kVAiroli /BBLR line-l / Ghatghar line/ Unit no.3 &4/ station transformer

3&4 tripped.


Station transformers No.3&4 were charged from 220 kV HV side at 02:43hrs and 03:05 hrs

respectively. The faulty B-phase CT in bus section-II (Sr. No.2010-58, M/s SCT make, Ratio

2400-1200/1A) was replaced with another CT(Sr.l o.2010-69, make M/s SCT, ratio 2400-

1200/1A, cap - 444.98bf, Tan delta - 0.209 %). The faulty CT was installed recently on

18/10/2012 & failed in 41 days. Also C and Tan delta of other CTs are measured and four

nos. of them are having higher tan delta values and their trend is rising. Bus section-II CB is

kept off. The unit is synchronized to grid through transfer (auxiliary) bus. LPT(front left)

diaphragm was replaced by TM.

The faulty CT was installed on 31/10/2012 and failed in 41 days. It was replaced with another

one. The busbar zone I &II were isolated on bus bar protection resulting into tripping of unit

no 3 & 4 T.A. sets, station transformer no 3&4.


ITEM NO. 3: Tripping of lines / ICTs:

The incidences of tripping of lines and ICTs during the period 01-01-2013 to 30-04-2013 are

enclosed at Annexure–3.

Committee noted.

ITEM NO. 4: Status of implementation in WR on Recommendations of Report on Grid disturbance on 30th and 31st July 2012

The Status of implementation in WR on Recommendations of Report on Grid disturbance on

30th and 31st July 2012 as on 01.05.2013 is given at Annexure-4.

CEA vide letter No. 6/AI/DST/GM-2013/441-449 dated 10.05.2013 has forwarded formats

for collecting information of status of action taken on the recommendations of the Enquiry

Committee. The updated status of implementation of various recommendations of the grid

disturbance enquiry committee as on 1st & 15th of each month is required to be forwarded to

CEA by RPCs by 3rd & 17th of every month regularly.


1) Information in Formats 1 to 3 is to be furnished by STU and CTU for month by

1st and 15th of the month.

2) Information in Format 4 is to be furnished by SLDCs/ WRLDC POSOCO for

the month by 1st and 15th of the month.

3) Information in Format 5, 7 & 8 is to be furnished by WRLDC POSOCO for the

month by 1st and 15th of the month.

4) Information in Format 6 is to be furnished by CTU for the month by 1st and 15th

of the month.

SE (P) stated that nodal officers may be designated by all the STUs, CTU and

WRLDC POSOCO who would be responsible to send the updated status by 1st &

15th of every month. The above information may please be forwarded through the

nodal officer of the above organisations to WRPC/WRLDC.

Nodal officers identified for submission of data are as follows;

1. WRLDC : Shri P.Pentayya GM WRLDC

2. PGCIL-I : DGM(OS)

3. PGCIL-II: DGM(OS)

4. NTPC WR-II : Shri D.Roychowdhari AGM(OS) & A.K.Chandelia

DGM(OS)

5. GETCO STU : Shri S.A.Patel.

6. GETCO SLDC : Shri B.B.Mehta, CE SLDC.

7. MSETCL STU : Shri Rajurkar SE

8. MSETCL SLDC : CE SLDC

9. MPPTCL STU : Shri Jain, CE (T&C)

10. MPPTCL SLDC:Shri P.A.R Bende CE SLDC

11. CSPTCL STU:Shri Rehman SE(T&C)

12. CSPTCL SLDC: Shri K.S.Manotia CE SLDC.


ITEM NO. 5: Implementation of Automatic Demand Management Scheme and GSES.

5.1 : Hon’ble CERC vide order dated 14.01.2013 on WRLDC petition No. 249/MP/2012

have directed RPCs to discuss the issue of “Implementation of the Automatic Demand

Management Scheme at the SLDC/Distribution Company level”.

In para 9 of aforesaid order CREC have quoted that

Quote

We have considered the submissions of the parties. With regard to the submission of NLDC

that overdrawal irrespective of the frequency should not be allowed, we intend to clarify that

at present, UI Regulations and Grid Code allow overdrawal within prescribed limits in

normal situations and therefore, no such directions can be issued which would be contrary to

the regulations. The petitioners have also sought directions from the Commission to the

States to implement Automatic Load Management Scheme and to provide the details of the

feeders which can be included in the Automatic Demand Management Scheme. We had

directed NRLDC in our order dated 17.8.2012 in Petition No.125/2012 to identify in

consultation with the CTU, CEA, STUs and SLDCs the feeders of the State network which

are incidental to the inter-State transmission of electricity which can be opened in case of

sustained overdrawal from the grid or any other imminent danger to the grid. In the context of

our direction, we are of the view that RLDCs need to be properly equipped to disconnect the

pre identified feeders in the State networks in the event of overdrawal which poses imminent

danger to the grid. To achieve this objective of automatic demand management scheme, there

may be technical and system constraints which need to be addressed through appropriate

technology. Since such technological improvements involve capital cost, we are of the view

that such proposals should be discussed at the RPC forums as an agenda item and the

recommendations/decisions of the RPCs should be placed before the Commission for

consideration and necessary directions.

Unquote

5.2 : In 116th PCM, GM, WRLDC made presentation on GSES during the meeting. The

10 logical conditions envisaged and control actions proposed by WRLDC were as

follows:


Sl. No

Logic Control Action Manual or Automatic Measurements as input for control action

(Local / Wide Area)

Control Action (Local / Wide Area)

1 ∆ P > 150 MW

∆ P = Actual-Schd

and freq< 50 Hz

Shed load in Constituent. In identified groups. Each group constituting 150 MW or 12% of the Schedule.

Rotation logic and sequence to be programmed at SLDC and WRLDC PLC

Stage 1 : Manual

Stage 2 : Automatic (From SLDC PLC after 15 minutes)

Stage 3 : Backup (from WRLDC PLC after 20 minutes)

Wide Area : Schedules & Drawal from SCADA system at LDCs

Wide Area:

signal sent from LDC to selected 220/132/66 kV sub-stations for tripping of feeders to get desired load relief

2 ∆ P < -150 MW

∆ P = Actual-Schd

and freq> 50 Hz

Send signal to designated power stations. Rotation logic and sequence to be programmed at SLDC and WRLDC PLC

Stage 1 : Manual

Stage 2 : Automatic (From SLDC PLC 15 minutes)

Stage 3 : Backup (from WRLDC PLC in 25 minutes)

Wide Area : Schedules & Drawal from SCADA system at LDCs

Wide Area:

signal sent from LDCs /WRLDC to power stations

3 Voltage <200 kV at sub-station for more than 5 minutes

Shed load at selected 220 kV sub-stations identified in S no 1 above.

Stage 1: Alarm (208 kV)

Stage 2: Automatic (200 kV for more than 5 minutes)

Stage 3: 185 kV 30 seconds

Local area:

Bus voltage Measurement at the selected 220 kV substations

Local area:

4 Key line/ICT loading crossing limits

Min(Z3, SIL, stability limit)

Shed load down stream

Stage-1: Manual (SLDC level)

Stage-2; Automatic through PLC

Local area: ICTs /Line Loading from SCADA system at LDCs

Wide Area : Signal sent to Substations selected for the ICTs and Line loading relief


5 Flows crossing TTC and ∆ P > 100 MW

Shed load in the feeders identified at Sl. No 1 on rotational basis.

Automatic Local area:

No. of measurements aggregated at LDC SCADA.

Wide Area:

Signal sent from LDC Many areas in state.

6 Sudden loss of generation > 1000 MW or loss of high capacity corridor

Loss of high capacity corridors

Automatic Local area: measurement at Substation on Change of 1000 MW on sum of line flows

Wide Area:

Trip feeders.

7 Angular difference exceeding cut off value

Shed load in designated areas

Automatic Wide Area Synchrophasor measurements at RLDC/SLDC

Wide Area:

Signal sent to 220/132/11 kV substations

8 UFR I: 49.0 Hz

UFR 2: 48.8 Hz

UFR3: 48.6 Hz

UFR4: 48.4 Hz

State peak load: UFR to cover at least 60% of the state peak load . Identify 220 kV substations.

Automatic Local Area Local area:

9 df/dt: 49.9 Hz plus 0.1, 0.2 Hz/sec

Designated feeder in each control area

Automatic Local area Local area

10 Islanding at 47.9 Hz

Power stations, loads

Automatic Local area Local area

In the 116th PCM the Committee members expressed that

(i) DISCOMs should be involved for taking decision especially regarding identification of loads for tripping under ADSM and GSES, since prioritization of load to be shed in DISCOMs is not unique and requires adherence to the regulatory directions.

(ii) As regards to deciding the logic for conditions at Sr. No. 3,4,6 & 7 comprehensive studies should be carried out and the same shall be vetted by WRPC and constituents of WR. The design of logic and control actions shall be done in consultation with the DISCOMs, STUs, SLDCs and Generators of WR.


(iii) As regards to the AULFS at Sr.No. 8 & 9 requires coordinate studies among the

WR, NR, ER & NER, since the quantum of load shedding is sensitive to power

number of the NEW grid. The sharing of this load shedding shall be decided

based on the present and future generation and demand senarieos of the regions.

(iv) Present islanding schemes/ SPS should be taken care off while designing ADSM

and GSES scheme.

1.3 : The suggestions were put up in the 22nd WRPC meeting held on 26.02.2013 at Gandhinagar where in following was agreed. i) The implementation of GSES and ADMS were agreeable in principle. ii) As the Automatic Demand Management Scheme is a subset/ part of GSES and therefore it was recommended that the same will be implemented along with GSES. iii) Settings of frequency based defense mechanisms and quantum of load shedding etc., needs to be co-ordinated with other regions of the NEW Grid. iv) Manual load shedding, Automatic load shedding by demand management and load shedding under AUFLS and df/dt of GSES requires to be co-ordinated to avoid overlap and have clear distinction between manual actions and automatic control actions. v) Logic, technology, communication facilities, funding and controlling agencies needs to be addressed. vi) Possibility of including WAMS data in the above schemes requires to be explored. The TCC recommended that to discuss the above issue a group comprising of representatives of concerned utilities at appropriate levels shall require to be formed and the group may place its recommendations to the WRPC for its vetting and approval.

1.4 : Accordingly, first meeting of the group formed for implementation of GSES and

ADMS was held on 22.04.2013 at WRLDC Mumbai. Following viewpoints emerged

during discussions:

i) The recommendations of this meeting shall be conveyed to NPC.

ii) The four stages envisaged in the GSES document of NLDC i.e. 49 Hz, 48.8

Hz, 48.6 Hz and 48.4 Hz was agreeable, keeping adequate room for distress

load shedding etc.

iii) The quantum of load relief identified in WR for Flat under-frequency relays is

658MW at 49.0Hz, 1315MW at 48.8Hz, 1330MW at 48.6Hz and 1345MW at

48.4Hz. As per existing scheme, WR sheds 6472 MW under df/dt for three stages and


the same is sufficient. WR had planned to shed 11120 MW under AUFLS and df/dt.

This is of the order of 28% of the demand catered by WR. The total load relief

quantum of 11120MW in Flat under-frequency and df/dt, has been arrived at by

factoring in the load variations due to voltage fluctuations, frequency dependence of

loads and seasonal variation in a feeder loads etc. It was also suggested that overall

load relief in all the stages under AUFLS shall be in the range of 30%. Since the

power number is around 3.5% of the load catered.

iv) It was decided that the NPC would be appraised to account for such load dependency

factors while deciding quantum of load under UFR scheme, by other regions.

v) Out of the 10 (Ten) system security concerns scenarios raised by GSES document (as

tabulated above), points (viii) and (ix) pertaining to AUFLS and df/dt were

recommended as above. Regarding point (x) Islanding, the group pointed out that

islanding schemes at Mumbai, Uran, Ahmedabad , Watwa are existing in WR.

Islanding loads cannot come under the general category and each island has to be

planned accordingly. No more island scheme is under consideration in WR. Further a

Task Force under Shri V. Ramakrishna Ex. Member (PS) CEA is discussing the

aspects of islanding and guidelines are being awaited.

vi) As regards to the proposed contingencies at Points (i) to (vii) in the GSES document

pertaining to tripping of EHV loads for overdrawl, over injection/ Under Drawl,

Under Voltage, line loading, power exceeding TTC, loss of generation in excess of

1000 MW and Angular separation, NLDC representative clarified that the above

tripping of loads is different from ADMS which is a load management scheme. The

WR constituents felt that the security threats apprehended by NLDC have to be

explained in greater detail. WR constituents further informed that manual action,

planned and distress load shedding by States is already under process. Further the

contingency scenarios at points (i) to (vii) of the GSES document are of localized in

nature and therefore the load mapping for these scenarios be done by WRLDC in

consultation with State SLDCs, STUs and DISCOMs. The load mapping for

contingency scenario at point (viii) shall be formulated by the study group of WR in

consultation with the State SLDCs.

vii) It was also felt that since ADMS is getting envisaged to automate these tasks. There

has to be clarity when the defence mechanism should operate and when manual/

automatic ADMS shall operate. Also the Hon’ble Commission CERC had queried

CTU to differentiate between ADMS and GSES. After a clarification on the above is

submitted by CTU, the above points may be taken up for discussion in the next

meeting of WR constituents.

It was decided that DISCOMs may begin the exercise of load mapping may


for their respective States keeping in view their Regulator’s directives so that

the IEGC clauses 5.4.2 (a) and (b) above are complied with and charting the

communication requirements assuming that suitable source of funding may be

made available. DISCOMs were requested to complete the exercise of load

mapping within two months and the matter can then be discussed in the next

meeting. MS I/C, WRPC requested DISCOM/SLDC to avoid overlapping of

feeders identified for different purposes of GSES scheme while carrying out

load mapping.

Committee noted.

ITEM NO. 6: Zone 3 settings of Distance Protection Schemes:

CEA have issued Manual on Transmission Planning Criteria which is effective from

01.02.2013 (the same is available at CEA website). Under para 20 of the “Manual on

Transmission Planning Criteria”, guidelines on zone-III setting to avoid tripping of lines in

extreme loading conditions has been given as follows

Quote

20 Guidelines for consideration of zone-3 settings

20.1 In some transmission lines, the Zone-3 relay setting may be such that it may trip under

extreme loading condition. The transmission utilities should identify such relay settings and

reset it at a value so that they do not trip at extreme loading of the line. For this purpose, the

extreme loading may be taken as 120% of thermal current loading limit and assuming 0.9 per

unit voltage (i.e. 360kV for 400kV system, 689kV for 765kV system). In case it is not

practical to set the Zone-3 in the relay to take care of above, the transmission licensee/owner

shall inform CEA, CTU/STU and RLDC/SLDC along with setting (primary impedence)

value of the relay. Mitigating measures shall be taken at the earliest and till such time the

permissible line loading for such lines would be the limit as calculated from relay impedence

assuming 0.95 pu voltage, provided it is permitted by stability and voltage limit

considerations as assessed through appropriate system studies.


Unquote.

The above guidelines were circulated to the WR constituents for implementation by WRPC

vide letter WRPC/Prot/GD/2012/289 dated 08.03.2013.

WRLDC vide letter WRLDC/MO-I/1658/2012/8960 dtd. 15.05.2013 have informed that,

NERC has formulated a Protective relay loadability standard named as PRC – 023 which

emphasize that protective relay settings shall not limit transmission loadability in the system

and shall not interfere with system operators’ ability to take remedial action to protect system

reliability. It should be set to reliably to detect all fault conditions and protect the electrical

network from these faults. Each Transmission Owner, Generator Owner, and Distribution

Provider shall evaluate relay loadability at 0.85 per unit voltage and a power factor angle of

30 degrees.

In view of the above, the Zone-3 settings for load encroachment needs to be deliberated and

the status on implementation of the above CEA guidelines be furnished. The distance

protection relays employed in WR are mainly having Quadrilateral, Mho and polygonal

settable characteristics.

All state utilities confirmed that the Zone-3 settings adopted are generally higher than

the line loadability limits given in para 20 of the “Manual on Transmission Planning

Criteria”

Committee expressed that all the utilities shall check Zone-3 settings for line loadability

given in the “Manual on Transmission Planning Criteria”, as above. Where ever the

Zone-3 settings violate the line loadability limits, the utility shall inform the same to

CEA under intimation to WRPC.


ITEM NO. 7: Other Items :

7.1.1 : SPS for CGPL units :

GETCO vide letter No SLDC/CE/MIS/CGPL-SPS/T-1184 dated 01.04.2013, have intimated

that there are six circuits for evacuation of power from CGPL, Mundra which has an installed

capacity of 4000MW(5x800MW) namely: 400kV D/C CGPL-Bhachau (PG)-Vadavi (Triple

snowbird conductor), 400kV D/C CGPL-Chorania (Triple snowbird conductor) & 400kV

D/C CGPL-Jetpur (Triple snowbird conductor). An SPS is required to be implemented for

specic contingencies as given below;

A) If any one circuit of 400kV D/C CGPL-Bhachau (PG) or any one circuit of 400kV

D/C CGPL-Chorania line trips, then it is very much necessary to back down the

generation from CGPL by at least 600-700MW or trip the highest generating unit

automatically through SPS so that loading on the remaining lines does not rise beyond.

B) If both circuits of 400kV D/C CGPL-Bhachau (PG) line or both circuits of 400kV

D/C CGPL-Chorania line trip, then two units having the highest quantum of generation

should trip automatically through SPS.

Further, GETCO vide letter No SLDC/CE/MIS/Mundra-UMPP/SPS/T-1581 dated

15.05.2013, have proposed following schemes for implementation of SPS for CGPL

units in case of overloading of the outlet lines from CGPL Mundra.

13. Loading on any outlet line of CGPL reaches 900MW for more than 10 seconds, there

should be an alarm.

14. Loading on any outlet line of CGPL reaches 1000MW for more than 3 seconds, RBS

should activate for reducing generation by 500MW in not more than 5 minutes.

15. Loading on any outlet line of CGPL reaches 1200MW, then there should be

instantaneous tripping of one unit having the maximum generation on bar.

Committee discussed and following was decided;


SPS for CGPL

CGPL Chorania‐1

Chorania‐2

Bhachau‐1

Bhachau‐2

Jetpur‐1

Jetpur‐2 Action at CGPL

>3100 X X >1500

Trip mills this will reduce generation by @500MW

>3100 X X >1500 >3100 X X >1500 >3100 X X >1500 >3100 X X >1500 >3100 X X >1500 >3100

>1200 Alarm for reduction in generation so that the Jetpur lines loadings are maintained around 1200MW

7.1.2 : SUGEN islanding scheme :

GETCO vide letter No SLDC/CE/MIS/PCM-WRPC/T-1704 dated 21.05.2013, have

intimated that SUGEN vide letter No. TPL/SUGEN/COMMERCIAL/11-12/0087 dated

14.09.2011, have submitted a proposal for islanding scheme for SUGEN Mega Power Project

for 1147.5MW.

Committee felt that a group comprising of GETCO, SLDC Gujarat, WRLDC and

WRPC may finalise the scheme and then the same shall be put up to PCM.

7.2 :Over-Voltage Protection for Transmission lines in Western Region

WRLDC vide letter WRLDC/MO-I/1658/2012/8960 dtd. 15.05.2013 have intimated that,

considerable number of critical 765/400 kV lines is being kept out for containing High

voltage. Also there are several cases of multiple tripping of feeders emanating from a single

node on over voltage. Multiple tripping on O/V at one node or in a single corridor may lead

to transmission depletion adversely affecting grid security. In such cases the drop off to pick

ratio should be increased to 99% while the over-voltage rating should be changed to 112 % to

increase the reliability of the grid. The high drop-off to pick-up ratio of the O/V relays (say

99% and above) ensure quick reset of the relay so as to avoid multiple tripping of feeders on

over voltage.

• For a standalone static type of relay the drop-off to pick-up ratio may be relooked and

modified to 99% at all locations in WR grid by the respective utilities / constituents.


• In case the relay is of multi-function numerical type where the over voltage function

is being utilized for O/V protection the vendor may be requested by the concerned utility to

modify the ratio (drop-off to pick up) to 99%.

Following nodes in western region are identified as high voltage node where line trip on over

voltage protection: Chandrapur, Parli, Raigarh, Raipur, Wardha, Indirasagar, Kolhapur,

Solapur, Karad, Rajgarh, Khandwa, Itarsi, Dhule, Seoni, Nagda , Kasor, Bhadrawati, Akola.

Hence the above changes may be discussed in the meeting and implemented on priority.

Matter may be taken as most urgent in view of reliable and secured grid operation.

Committee discussed the matter in length as regards to logic implemented in the over voltage relays vis a vis the performance of the relays in field as follows; 1. In general the O/V relays are set for drop off to pick up ratio of 95%. 2. For a typical bus having 10 outgoing lines, with nominal voltage of 400kV, the pick

up voltage of the relay at 110%, would be 440kV and the drop off voltage of the relay would be 418kV.

3. In case the voltage at the bus touches 440kV, all the O/V relays would pick up. If the voltage remains above 418kV for period more than the time delay setting of the relay, all the lines would trip.

4. In case, one of the lines trip on O/V, for a typical bus the voltage would fall by 1% (i.e. the bus voltage would fall to 435.6kV), which is still above the drop off voltage of 418kV and therefore more outgoing lines (3 to 4 lines) from the bus would trip, till the bus voltage falls below 418kV, thereby resetting the picked up over voltage relays of the lines in service. In practice, it has been observed that multiple lines from the same substation are not tripping on O/V.

5. As seen from the above performance of the O/V relays, the logic implemented in the O/V relays as regards to the drop off to pick up ratio may be different than the conventional understanding about this ratio.

From the above discussions, it was concluded that even after tripping of one of the line on O/V, the bus voltages drops by only 1% and under this scenario, the O/V relays on other lines should not drop off and should trip on O/V, if the drop off to pick up ratio set is 95%. In field this is not happening, suggesting that the O/V logic needs to be checked. MSETCL was requested to look into the details of the logic by carrying out tests on the different make O/V relays. The conclusions would be put up before next PCM.


7.3 : Status of Auto - Reclosure of Transmission lines in Western Region

WRLDC vide letter WRLDC/MO-I/1658/2012/8960 dtd. 15.05.2013, have intimated that, in

the recent past, there were several times when the Auto-reclosure of the lines did not operate.

During the occurrence at 400/220 kV BALCO S/s on 27th April’13 it was observed in the DR

that the auto-reclosure of 400 kV Balco-Korba line was blocked from both end which led to

tripping of line on transient R-phase to earth fault. Also it was observed that A/R at Balco

was block and it was observed that a time delay of 1 second was provided to trip other two

poles. There was no information to WRLDC regarding the blocking of A/R of this lines.

In view of the above, there is a need to verify the auto-reclosure status for all

765/400 kV Lines in western region. Constituents are requested to provide the A/R status of

all the 765/400 kV Lines. If the A/R of any 765/400 kV line is blocked, the reason for that

need to be mentioned and WRLDC to be intimated.

Committee felt that utilities should always keep the A/R in service.

7.4 : Status of Bus Coupler and Bus Bar protections at S/s

WRLDC vide letter WRLDC/MO-I/1658/2012/8960 dtd. 15.05.2013, have intimated that,

there has been several occasions in the grid when the Bus Couplers and Bus-Bar Protections

are kept out at substation without any intimation to WRLDC/SLDCs. In case of Bus coupler

being kept out of service, all the feeders are connected on both buses. During any fault on one

of the bus, it will lead to tripping of all the feeders as the fault will be fed to both buses.On

the same, if Bus bar protection is kept out of service, any fault on either of bus will led to

tripping of feeders on both buses.

On 10-11-2012, 400 kV Birsinghpur Bus bar protection was kept out of service for testing

without any intimation to WRLDC/MP-SLDC. All the feeders tripped from both buses due to

bus fault on BUS-II. Also during occurrence at 220 kV Raigarh (CSPTCL) ,it was found that

Bus coupler and bus-bar protection are not in service and all feeders were connected on both

the buses. During the fault on Bus II on 19-03-2013, all the feeders tripped from remote end.

All the constituents are required to give the intimation to WRLDC and their respective

SLDCs if keeping the bus-coupler / Transfer Bus-Coupler/Bus-bar protection out of service.

Also it is advised to give the details of transmission elements in the substation which are out

of service to WRLDC/SLDCs.


GETCO representative informed that BB protection is installed at all 400kV S/Ss., and

7 nos of 220kV S/S have single Bus system and BB protection would be provided.

MSETCL representative informed that BB protection is installed at all 400kV S/Ss. &

220kV S/S. MSPGCL representative informed that BB protection is installed at all

400kV S/Ss., and at 3 nos of 220kV S/S BB protection would be provided. MPPTCL

representative informed that BB protection is installed at all 400kV S/Ss., and out of

55nos of 220kV S/Ss, at 29nos of S/Ss BB protection have been provided and at 28 nos

of 220kV S/Ss BB protection scheme would be provided. CSPTCL representative

informed that BB protection at 5 nos of S/S is under procurement and at 11nos of S/Ss,

the same has been provided.

Committee requested utilities to provide the BB protection at the earliest, wherever not

commissioned.

7.5: Review of relay setting for 400kV D/C Pirana(PG)-Pirana (Torrent) line:

GETCO vide letter SLDC/CE/MIS/TPGL/Pirana(T) tripping-28.02.13/829 dtd. 07.03.2013,

have intimated that on 28.02.13 at 14:35hrs, 400kV Sugen-Pirana(T) line tripped on Z1 Y-B

(Dist.-84km. At the same time, 400kV Pirana(PG)-Pirana(T) line 1 & 2 tripped on DEF at

Pirana (PG) end resulting in inter tripping at Pirana (T) end, which led to blackout at

Pirana(T) substation. Further PGCIL was requested for thorough checking of protection

settings adopted for the above lines.

Torrent Power representative informed that the settings have been reviewed. PGCIL

representative informed that they would look into the issue.

7.6 : Time synchronisation, non-working of DR and Main-2 of Ranchodpura line-2

at Dehgam S/S.

PGCIL vide letter WRTS II/O&M/273/AV/1211 dated 30.03.2013 &

WRTS/DEH/SS/385/113 dtd. 28.01.2012, have intimated that the pending protection issues

related with GETCO bays at Dehgam S/S have not been attended so far and requested

GETCO for rectification of the following issues;

(i) Main-2 Distance Protection Relay (Siemens make 7SA522) of 400kV Dehgam-Ranchodpura feeder is faulty since April 2011. (ii) In all the 400kV GETCO bays (Ranchodpura-1&2, Soja,Wanakbori) at Dehgam S/S,


both Main-1 & Main-2 DPRs are of same make and principle (i.e. Siemens make & 7SA522 model). The same needs to be replaced. (iii) The existing DR & its PC are not working and have become absolete. Therefore DR needs to be configured in Main-1/Main-2 protection along with wiring of digital inputs & GPS time synchronisation.

GETCO representative as regards to (i), informed that REL 670-4nos of relays with

time synchronisation would be taken into service within one month.

7.7 : Auto recloser of 400kV Satpura-Koradi line:

MPPTCL vide letter No. 07-05/STP-79/487 dtd. 15.02.13, have intimated that there is a

repeated failure of auto reclose of 400kV of 400kV Satpura-Koradi line at Satpura end, since

the auto reclose from Koradi end was successful on transient faults on line and requested

PGCIL to attend the failure of the auto reclose at Satpura S/S.

PGCIL representative informed that A/R scheme would be replaced by July end.

7.8: DPR Submission to CEA :

CEA vide email dated 26.04.2013, have circulated the guidelines for preparation of DPRs for

R&U of sub-stations by the STUs, the same was forwarded to all the members of PCM and

also STUs. DPRs received from GETCO, MSETCL, MPPTCL/MPPGCL and CSPTCL were

consolidated in the format circulated by CEA vide letter No. 6/AI/DST/GM-2013 dated

13.05.2013. Also the hard copies were submitted to CEA for further processing.

Committee noted.

ITEM NO. 8: Any other item

-NIL-

ITEM NO. 9: Date and Venue of the next meeting

The date and venue of the next PCM will be intimated separately.

Annexure-1

Sl. No. Organisation & Name Designation E-mail Mobile No.

WRPC

1 Shri S.D. Taksande M S [email protected] 9820878384

2 Shri Satyanarayan S. S E [email protected] 9223399938

3 Shri P.D.Lone E E [email protected] 9867622823

4 Shri Shiva Suman A D [email protected] 9869910968

MSETCL/MSPGCL

5 Shri Shashank Jewalikar S E [email protected] 8554995003

6 Shri Peeyush S. Sharma E E [email protected] 9769213805

7 Shri D.M. Bhadikar E E [email protected] 9423424459

8 Shri C. L. Bharamgwnde Dy E E [email protected] 8411001562

9 Shri Rahul Mandlik A E [email protected] 8888831351

10 Shri S.L. Laghate Dy.E E [email protected] 8888834119

MPPGCL/MPPTCL

11 Shri P.C. Soni S E [email protected] 9425806552

12 Shri R.S. Shrivastava S E [email protected] 9425805010

13 Shri Sunil Yadav E E [email protected] 9425804916

CSPTCL

14 Shri M. Z. Rahman S E [email protected] 9425590253

15 Shri K. K. Yadav E E [email protected] 9907432665

GETCO

16 Shri B.B. Mehta C E [email protected] 9879200736

17 Ms. Snehal A. Patel E E [email protected] 9925211041

WRLDC

18 Shri P. Pentayya G M [email protected] 9869072437

19 Ms. Pushpa Seshadri C M [email protected] 9869404482

20 Shri Chandan Kumar Engr. [email protected] 9869251460

LIST OF PARTICIPANTS OF 117th PCM MEETING HELD ON 03.06.2013 AT MUNDRA

POWERGRID21 Shri Ankit Vaish Sr. Engr. [email protected] 9409305725

22 Shri Ram Kishor Soni Mgr. [email protected] 9408707252

23 Shri Vaibhav Bhandarkar Dy. Mgr.

NTPC

24 Shri R.K. Aash A. G. M. [email protected] 9429408449

25 Shri Jitendra Tewari A. G. M. [email protected] 9425177965

26 Shri R.A. Reddy Sr. Supdt. [email protected] 9424141554

NPCIL

27 Shri M.M. Rai SO/F [email protected] 9423377226

28 Shri B.M. Shah SO/F [email protected] 9428821848

29 Shri Nayan Shah SO/D [email protected] 9420881419

30 Shri A.N. Thakur Head Elect. [email protected] 9423081584

Tata Power

31 Shri Alok Uppal C. M. [email protected] 9099006430

32 Shri Girish Jawale Mgr. [email protected] 9223311419

33 Shri K.N. Athavale G.M. [email protected] 9227295358

APL

34 Shri C. Bobade G.M. [email protected] 8980802255

35 Shri Sanjay Bhatt Sr. M. [email protected] 909900521

VEDANTA

36 Shri Suresh Ch. Mishra Mgr. suresh.mishra@vedabta,co.in 9630033349

Reliance Infra

37 Shri M. R. Waingankar [email protected] 9324216664

38 Shri S.V. Sawant D. G. M. [email protected] 9325118288

Torrent Power

39 Shri Kamlesh Trivedi A. G. M. [email protected] 9227246950

JPL40 Shri Naresh Punjabi Sr. G.M. [email protected] 7898905011

1 Minutes of 117th Protection Committee of WRPC held on 03rd & 04th June 2013 at CGPL Mundra.

ANNEXURE-3 TRIPPINGS OF LINES / ICTS

Sr.No. Name of S/S Line/ICT Utility Tripped on Restored on Reason/Remark

Date Time Date Time 1 400KV

Birsinghpur Katni -II MPPGCL

(Y) 10-Jan-

13 17:01 10-Jan-

13 18:54 Line tripped on Overvoltage

on DT received at Katni end.

2 400KV Birsinghpur

Katni -II MPPGCL (Y)

13-Jan-13

17:04 13-Jan-13

18:18 Line tripped on Overvoltage on DT received at Birsinghpur end.

3 400KV Birsinghpur


14-Jan-13

16:02 14-Jan-13


4 400KV Birsinghpur


17-Jan-13

04:04 17-Jan-13


5 400KV Birsinghpur

Katni -I MPPGCL (Y)

20-Jan-13

02:14 20-Jan-13


6 400KV Birsinghpur

Katni -I MPPGCL (Y)

24-Jan-13

03:01 24-Jan-13


7 400KV Birsinghpur

Katni -I MPPGCL (Y)

5-Feb-13

01:56 5-Feb-13


8 400KV Birsinghpur

Katni -I MPPGCL (Y)

6-Feb-13

23:21 7-Feb-13


9 400KV Birsinghpur

Katni -I MPPGCL (N)

9-Feb-13

03:20 9-Feb-13


10 400KV Birsinghpur

Katni -I MPPGCL (N)

12-Feb-13

00:57 12-Feb-13



Katni -I MPPGCL (N)

14-Feb-13

23:50 - - Line tripped on Overvoltage on DT received at Birsinghpur end.

12 400KV STPS Sarni.

I.S.P MPPGCL (N)

18-Jan-13

23:06 19-Jan-13

05:15 Line tripped on Overvoltage due to DT received at STPS end.


I.S.P MPPGCL (N)

19-Jan-13

05:00 19-Jan-13

05:30 Line tripped from both end on `B` Phase fault.


I.S.P MPPGCL (N)

20-Jan-13

02:15 20-Jan-13



I.S.P MPPGCL (N)

20-Jan-13

22:27 21-Jan-13




I.S.P MPPGCL (Y)

22-Jan-13

04:04 22-Jan-13



I.S.P MPPGCL (Y)

22-Jan-13

12:02 22-Jan-13



I.S.P MPPGCL (Y)

22-Jan-13

20:55 23-Jan-13



I.S.P MPPGCL (Y)

23-Jan-13

18:20 23-Jan-13



I.S.P MPPGCL (Y)

24-Jan-13

17:55 25-Jan-13



I.S.P MPPGCL (Y)

25-Jan-13

22:25 27-Jan-13



I.S.P MPPGCL (Y)

28-Jan-13

17:00 28-Jan-13



I.S.P MPPGCL (Y)

29-Jan-13

16:09 29-Jan-13



I.S.P MPPGCL (Y)

29-Jan-13

17:01 30-Jan-13



I.S.P MPPGCL (Y)

30-Jan-13

18:00 1-Feb-13



I.S.P MPPGCL (Y)

1-Feb-13

18:00 2-Feb-13



I.S.P MPPGCL (Y)

4-Feb-13

19:55 5-Feb-13



I.S.P MPPGCL (Y)

10-Feb-13

23:18 11-Feb-13



I.S.P MPPGCL (Y)

11-Feb-13

22:40 12-Feb-13



I.S.P MPPGCL (Y)

15-Feb-13

23:35 16-Feb-13



I.S.P MPPGCL (Y)

16-Feb-13

12:00 16-Feb-13



I.S.P MPPGCL (Y)

19-Feb-13

23:22 20-Feb-13



Itarsi MPPGCL (Y)

19-Feb-13

10:25 19-Feb-13

11:35 Line tripped from both end on `Y` Phase fault.



I.S.P MPPGCL (Y)

2-Mar-13

16:07 2-Mar-13



I.S.P MPPGCL (Y)

10-Mar-13

16:03 10-Mar-13



I.S.P MPPGCL (Y)

14-Mar-13

16:05 14-Mar-13



I.S.P MPPGCL (Y)

15-Mar-13

17:00 15-Mar-13



I.S.P MPPGCL (Y)

16-Mar-13

17:02 17-Mar-13



I.S.P MPPGCL (Y)

21-Mar-13

03:35 21-Mar-13



I.S.P MPPGCL (Y)

24-Mar-13

17:08 24-Mar-13



I.S.P MPPGCL (Y)

26-Mar-13

17:02 26-Mar-13



I.S.P MPPGCL (Y)

27-Mar-13

16:05 27-Mar-13



220KV Satna

MPPGCL (Y)

4-Jan-13 06:42 4-Jan-13 12:31 Line tripped on `C` phase, Zone-II on tripping of Main Bus-II with all feeders at remote end.


220KV AMK-2

MPPGCL (N)

15-Jan-13

02:40 15-Jan-13

03:01 Line tripped from both end on `B` Phase fault.


220KV Sukha

MPPGCL (N)

15-Jan-13

17:45 15-Jan-13

23:00 Tripped on B Phase fault on Birsinghpur end.


220KV Sukha

MPPGCL (N)

15-Feb-13

02:45 16-Feb-13

13:13 Line tripped from both end on `C` Phase Zone-I.


220KV Sukha

MPPGCL (N)

26-Feb-13

10:50 26-Feb-13

04:28 Line tripped from both end on `R` Phase fault. Zone-I


220KV Sukha

MPPGCL (N)

15-Mar-13

16:34 15-Mar-13

17:23 Line tripped from both end on `C` Phase fault. DPR optd.


220KVPali IC-3

MPPGCL (N)

15-Mar-13

16:38 15-Mar-13

17:52 Line tripped from Birsinghpur on `C` Phase fault.; Z-2


220KV Pali IC-4

MPPGCL (N)

15-Mar-13

16:38 15-Mar-13

18:54 Line tripped from Birsinghpur on `C` Phase fault.; Z-2


220KV Sukha

MPPGCL (N)

15-Mar-13

17:32 15-Mar-13

18:41 Line tripped from Birsinghpur on `R` Phase fault.; DPR optd.


220KV Sukha

MPPGCL (N)

20-Mar-13

12:25 20-Mar-13

12:54 Line tripped on `R` Phase fault to E/F.; DPR optd.



220KV Sukha

MPPGCL (N)

20-Mar-13

13:01 20-Mar-13

17:14 Line tripped on `R` Phase fault to E/F.; DPR optd.


220KVPali IC-1

MPPGCL (N)

23-Mar-13

16:40 23-Mar-13

21:08 Line tripped on Zone-II Protection due to failure of Y phase Bus PT at Pali S/S of MPPTCL alongwith tripping of Unit – 1, 3 & 4 of SGTPS due to voltage dip.


220KVPali IC-2

MPPGCL (N)

23-Mar-13

16:40 23-Mar-13

21:22 - do -


220KVPali IC-3

MPPGCL (N)

23-Mar-13

16:40 24-Mar-13

12:48 - do -


220KVPali IC-4

MPPGCL (N)

23-Mar-13

16:40 23-Mar-13

18:20 - do -


220KV Satna

MPPGCL (N)

28-Mar-13

09:55 28-Mar-13

10:08 Line tripped on À` Phase to Earth Fault at Satna end

59 220KV STPS, Sarni.

Sarni IC-II MPPGCL (N)

12-Feb-13

08:05 12-Feb-13

08:35 Line tripped on transient phase to phase ( Y + B) fault with E/F , Zone-I & Zone-II.


Sarni IC-I - 29-Mar-13

13:45 29-Mar-13

14:34 Line tripped on `Y` Phase to E/F.


Sarni IC-II - 29-Mar-13

13:45 29-Mar-13

14:32 Line tripped on `R` Phase to E/F.;

62 220KV ATPS, Chachai

220KV Jabalpur # 2

- 15-Jan-13

17:45 15-Jan-13

18:15 Line tripped on Z-2 Protection from Amarkantak end.


220KV Jabalpur # 2

MPPGCL (Y)

24-Jan-13

06:36 24-Jan-13

07:07 Line tripped on transient phase fault, Zone-I from Amarkantak end.


220KV Jabalpur # 2

MPPGCL (Y)

15-Feb-13

22:07 15-Feb-13

22:18 Line tripped on À` Phase fault, DPR optd.


220KV Birsinghpur #3

MPPGCL (Y)

16-Feb-13

01:10 16-Feb-13

01:23 Line tripped on À ` Phase fault to E/F.; Zone-I.


220KV Sukha

MPPGCL (Y)

16-Feb-13

15:22 16-Feb-13

16:16 Line tripped on `C ` Phase, Earth Fault, Zone-I.


220KV Jabalpur #1

MPPGCL (Y)

16-Feb-13

18:10 16-Feb-13

18:18 Line tripped on `C ` Phase Fault, Zone-I.


220KV Jabalpur #2

MPPGCL (Y)

16-Feb-13

20:44 16-Feb-13

20:56 Line tripped on `C ` Phase Fault, DPR optd.


220KV Jabalpur #2

MPPGCL (Y)

23-Feb-13

08:36 23-Feb-13

08:45 Line tripped on `B ` Phase to Earth Fault, Zone-I.



220KV Jabalpur #2

MPPGCL (Y)

25-Feb-13

06:00 25-Feb-13

06:11 Line tripped on À ` Phase Fault, Zone-I.


220KV Sidhi

MPPGCL (Y)

11-Mar-13

14:38 11-Mar-13

14:51 Line tripped on `C ` Phase Fault, Zone-I.


220KV Jabalpur #1

MPPGCL (Y)

15-Mar-13

17:20 15-Mar-13

17:28 Line tripped on `C ` Phase Earth Fault, Zone-I.

73 400kV khedamara S/S

400kV Koradi

CSPTCL (Y)

25-Jan-13

00:24 25-Jan-13

01:25 Feeder tripped and A/R from both ends.

74 400kV Bhilai S/S

400KV Seoni

CSPTCL (Y)

25-Jan-13

00:24 25-Jan-13

07:19 Feeder tripped from both ends on O/V.

75 400kV Bhilai S/S

400KV Seoni

CSPTCL (Y)

12-Jan-13

17:32 12-Jan-13

19:08 Tripped from both ends due to O/V at Seoni end.

76 400kV Bhilai S/S

400KV Seoni

CSPTCL (Y)

11-Mar-13

14:18 11-Mar-13

15:37 Line tripped on DT command sent.

77 400kV Bhilai S/S

400KV Seoni

CSPTCL (Y)

12-Mar-13

17:05 12-Mar-13

19:43 Line tripped on O/V Protn.

78 400kV Khedamara S/S

400kV Korba west feeder

CSPTCL (Y)

23-Feb-13

10:40 23-Feb-13

10:55 Line tripped on O/V Protn.

79 400kV Khaperkheda S/S

400/220kV ICT- I

MSETCL (Y)

23-Feb-13

17:27 23-Feb-13

18:09 NDR Operation , due to Weather condition Hevy rains with lightening.

80 400kV Khaperkheda S/S

400/220kV ICT- II

MSETCL (Y)

23-Feb-13

19:16 23-Feb-13


81 400kV Koradi S/S

400KV Bhusawal

MSETCL (Y)

23-Feb-13

19:17 23-Feb-13


82 400kV Koradi S/S

400KV Indiabull Feeder

MSETCL (Y)

21-Mar-13

07:20 21-Mar-13

10:06 Line tripped due to reactor failure.

83 400kV Koradi S/S

220KV Jabalpur #I

CSPTCL (Y)

15-Mar-13

17:20 15-Mar-13

17:28 Line tripped on `C ` Phase Earth Fault, Zone-I.

84 220kV TAPS S/S

220KV Vapi

NPCIL (Y)

6-Mar-13

21:05 6-Mar-13

22:39 Transient Tripping, Vapi end Breaker tripped on over load.

85 220kV TAPS S/S

220KV Borivali

NPCIL (Y)

6-Apr-13

21:30 7-Apr-13

17:33 R-Ph jumper snapped at loc No 46/0 and replaced. Conductor String done between Loc No: 49/0 7 46/9.

86 220kV KAPS S/S

220KV Haldarwa

NPCIL (Y)

12-Mar-13

07:22 14-Mar-13

08:00 Line tripped on Distance Protn. at remote end..

87 400KV Raipur - Wardha # 2

PGCIL (Y) 2-Jan-13 9:20 2-Jan-13 10:41

Line tripped on R-E fault , F.L 46.5KM from Wardha , 347 Km from Raipur.

88

400KV Raipur - Wardha # 1

PGCIL (Y)

2-Jan-13 18:14 2-Jan-13 18:24

Line tripped due to relay mal operation of Reactor back up impedance relay at wardha end .


89

400KV Raipur-Bhadrawati # 1

PGCIL (Y)

4-Jan-13 12:36 4-Jan-13 12:36

Line auto reclosed successfully at both ends on Rph-e fault, FL=293.6 km from Bhadrawati and 27.7km from raipur end

90 400KV Wardha -Mouda # 2

PGCIL (Y) 7-Jan-13 8:48 7-Jan-13 12:08 Line tripped due to CT failure

at NTPC Mouda end . 91

400KV Wardha - Mouda # 2 PGCIL

(Y) 14-Jan-13 11:52 14-Jan-

13 15:24 Line got tripped due to receipt of DT from Mouda end during testing at Mouda.

92 400KV Wardha -Parli # 1

PGCIL (Y) 15-Jan-

13 13:41 15-Jan-13 13:54

Line tripped on B-E fault only at Wardha end , F.L 138KM from Wardha .

93 400KV Koradi- Satpura

PGCIL (Y) 19-Jan-

13 5:00 19-Jan-13 5:30

Line tripped only at Satpura end but hanging from Koradi end.

94 400KV Parli-Parli # 1

PGCIL (Y) 24-Jan-

13 14:17 24-Jan-13 22:58

Line tripped due to DT received from Parli (MSETCL)end.

95 400KV Parli-Parli # 2

PGCIL (Y) 24-Jan-

13 14:19 25-Jan-13 8:12

Line tripped due to DT received from Parli (MSETCL)end.

96

400KV Koradi-Bhilai

PGCIL (Y) 25-Jan-

13 0:24 25-Jan-13 0:24

Line autoreclosed successfully at both ends on Yph-e fault ,FL=266km from Koradi end

97 400KV Raipur -KWPCL-Raigarh

PGCIL (Y)

29-Jan-13 12:37 29-Jan-

13 20:50

400KV Raipur-KWPCL tripped due to B-E fault , F.L 3.15Km from KWPCL end (KWPCL portion ) . A/R unsuccessful at KWPCL end DT received at Raipur end .

98 400KV Kolhapur - Mapusa # 2

PGCIL (Y) 14-Feb-

13 9:58 14-Feb-13 10:30

Line tripped due to Bus fault at Kolhapur SS(MSETCL), Rph CVT Bus-1 blasted.

99

400KV Wardha-Parli # 2

PGCIL (Y) 15-Feb-

13 17:41 15-Feb-13 17:41

Line auto reclosed successfully on Rph-e fault ,FL=37.4km From Wardha end

100 400KV Kolhapur - Mapusa # 2

PGCIL (Y) 26-Feb-

13 6:47 26-Feb-13 7:57

Line tripped due to heavy fog at Kolhapur side , F.L 148.61Km from Mapusa end.

101

400KV Parli - Parli # 2

PGCIL (Y) 3-Mar-

13 18:02 3-Mar-13 18:55

Line tripped due to failure of CT at Parli ( MSETCL).Busbar protection operated at Parli ( MSETCL ) end.

102 400KV Koradi - Bhilai

PGCIL (Y) 4-Mar-

13 20:00 4-Mar-13 20:00

A/R successfully at both ends on B ph - E fault 74.21Km from Bhilai end.

103

400KV Raigarh- Sterlite # 2

PGCIL (Y) 5-Mar-

13 13:36 5-Mar-13 14:16

Line tripped on R-Y fault , fault location around 16km from sterlite end , fault comes under Sterlite portion .


104

400KV Raigarh - SEL # 1

PGCIL (Y) 19-Mar-

13 11:53 19-Mar-13 13:33

Line tripped on Y- ph to earth fault ,FL= 9.8Km from SEL end ,comes in SEL's LILO Portion.

105

400KV Raipur-KWPCL (lilo of 400KV Raipur-Raigarh # 2)

PGCIL (Y)

21-Mar-13 17:03 21-Mar-

13 18:06 Line tripped due to Bph-e fault . Fault comes under KWPCL Jurisdiction.

106

765 Kv Seoni - Bilaspur # 2

PGCIL (Y) 21-Mar-

13 15:17 21-Mar-13 15:17

Line A/R successfully at both ends don B ph - Earth fault. Fault distance is 46.88 Km from Seoni S/S

107 MUNDRA-JETPUR II 400kV

PGCIL (Y) 05/01/2013;11:15 05/01/2013;12:54 A/T on Y-B Ph Fault.

108 MUNDRA-JETPUR I 400kV

PGCIL (Y) 06/01/2013;21:26 07/01/2013;21:06

A/T on R-ph to E/F due to failure of Metering CT at Mundra CGPL.

109 KHANDWA-RAJGARH I 400kV

PGCIL (Y) 10/01/2013;13:01 11/01/2013;09:47

Line A/T on operation of O/V at Rajgarh end.

110 MUNDRA-JETPUR I 400kV

PGCIL (Y) 10/01/2013;17:40 10/01/2013;18:04

A/T on B ph to E/F (persisting fault)

111

ICT2 JABALPUR 400/220kV

PGCIL (Y)

15/01/2013;17:43 15/01/2013;19:22

A/T on operation of Transformer Back up Over Current Protection due to Blasting of 220kV CT at MPPTCL 220kV S/Y.

112 SEONI-KHANDWA I 400kV

PGCIL (Y) 17/01/2013;23:17 18/01/2013;07:18

A/T due to operation of O/V at Khandwa

113 VINDHYACHAL-JABALPUR IV 400kV

PGCIL (Y) 17/01/2013;23:18 18/01/2013;07:13

A/T due to operation of O/V at V'chal.

114 ITARSI-INDORE II 400kV

PGCIL (Y) 26/01/2013;02:07 26/01/2013;02:29

A/T due to B Phase to Earth Fault

115 ITARSI-INDORE II 400kV

PGCIL (Y) 30/01/2013;02:34 30/01/2013;02:59

A/T due to B Phase to Earth Fault

116 KAWAS-NAVSARI (PG GIS) I 220kV

PGCIL (Y) 31/01/2013;01:59 31/01/2013;10:25

A/T on R-ph to E/F at both ends due to dense Fog

117 NAVSARI (PG GIS)-NAVSARI II 220kV

PGCIL (Y) 31/01/2013;02:11 31/01/2013;11:00


118 NAVSARI (PG GIS)-NAVSARI I 220kV

PGCIL (Y) 31/01/2013;02:23 31/01/2013;10:43


119 KAWAS-NAVSARI (PG GIS) II 220kV

PGCIL (Y) 31/01/2013;03:42 31/01/2013;10:50


120 KAWAS-HALDARWA II 220kV

PGCIL (Y) 31/01/2013;04:47 31/01/2013;05:37


121 GANDHAR-NAVSARI (PG GIS) II 400kV

PGCIL (Y) 31/01/2013;05:35 31/01/2013;06:14


122 GANDHAR-NAVSARI (PG GIS) I 400kV

PGCIL (Y) 31/01/2013;06:36 31/01/2013;11:33

A/T on B-ph to E/F at both ends due to dense Fog

123 INDORE-ASOJ II 400kV PGCIL (Y) 05/02/2013;14:07 05/02/2013;14:37

A/T on R-ph to E/F at both ends (persisting fault)


124 MUNDRA-JETPUR II 400kV

PGCIL (Y) 06/02/2013;01:15 06/02/2013;18:33

A/T at both ends on R-ph to E/F due to snapping of R-ph conductor

125 INDORE-ASOJ II 400kV PGCIL (Y) 08/02/2013;03:32 08/02/2013;06:26

A/T on operation of O/V at Asoj end (GETCO).

126 GANDHAR-NAVSARI (PG) I 400kV

PGCIL (Y) 11/02/2013;12:42 11/02/2013;13:22

A/T only at N'sari (GIS) due to receipt of D/T from Gandhar


PGCIL (Y) 11/02/2013;12:42 11/02/2013;13:41

A/T only at N'sari (GIS) due to receipt of D/T from Gandhar

128 SEONI-KHANDWA I 400kV PGCIL (Y) 11/02/2013;23:01 12/02/2013;07:50

A/T on operation of O/V at Khandwa

129 SEONI-KHANDWA II 400kV

PGCIL (Y) 15/02/2013;05:22 15/02/2013;06:06

A/T on operation of O/V at Khandwa

130 SATNA-BINA(PG) I 400kV PGCIL (Y) 15/02/2013;11:18 16/02/2013;15:42

A/T on B ph to E/F, due to insulator flashover

131 VINDHYACHAL-SATNA IV 400kV

PGCIL (Y) 16/02/2013;01:46 16/02/2013;06:11

A/T due to operation of O/V at Satna

132 Sasan-Jabalpur 400 kV PGCIL (Y) 16/02/2013;19:34 17/02/2013;16:22

A/T on B-ph to E/F at both ends due to operation of B/B protection at Sasan S/S.

133 JABALPUR-ITARSI II 400kV

PGCIL (Y) 19/02/2013;11:00 19/02/2013;18:44

A/T on R-Y-ph to ph Fault due to R-ph Jumper broken


PGCIL (Y) 24/02/2013;15:57 24/02/2013;16:31

A/T on R -ph to E/F ,during cutting of Teak tree by Forest deptt


PGCIL (Y) 05/03/2013;22:11 05/03/2013;23:28

A/T only at N'sari (GIS) end due to receipt of DT from NTPC Gandhar

136 SUGEN-VAPI 400kV PGCIL (Y) 06/03/2013;21:04 08/03/2013;19:58

A/T on B-Ph to E/F due to snapping of Conductor

137 MUNDRA-LIMBDI I 400kV PGCIL (Y) 08/03/2013;15:48 08/03/2013;22:45

A/T on Y-B ph to ph fault due to opening of Jumper

138 ICT#1 at SATNA 765/400kV PGCIL (Y) 14/03/2013;17:19 14/03/2013;18:40

A/T due to Flying objects fell on the charged area during heavy rain & thunderstorm.


PGCIL (Y) 14/03/2013;20:43 26/03/2013;18:52

A/T due to collapse of tower at Loc no. 81 during heavy rain & thunderstorm.

140 SASAN (RELIANCE) - JABALPUR 400kV

PGCIL (Y) 14/03/2013;20:43 04/05/2013;19:10


PGCIL (Y)

15/03/2013;22:31 15/03/2013;23:01

A/R successfully on B ph to E/F but tripped due to DT Receive on operation of O/V at Seoni S/s

142 GANDHAR-DEHGAM I 400kV

PGCIL (Y)

16/03/2013;16:22 16/03/2013;18:27

A/T on reciept of D/T from Gandhar NTPC due to operation of B/B Protection at Gandhar NTPC.

143 SHUJALPUR-NAGDA I 400kV

PGCIL (Y) 16/03/2013;18:24 17/03/2013;11:20

A/T tripped on B-E Fault. (persisting fault)

144 MUNDRA-LIMBDI I 400kV PGCIL (Y) 20/03/2013;14:23 20/03/2013;14:46

A/T on B-Ph to E/F due to snapping of B phase Jumper


145 BHACHAU-RANCHODPURA II 400kV

PGCIL (Y) 21/03/2013;11:37 21/03/2013;19:18

A/T on R & B ph -ph fault due to snapping of Jumper

146 400kV VINDHYACHAL-SATNA I

PGCIL (Y) 06/04/2013;11:51 06/04/2013;11:51

A/R successful at both ends on transient Y-Ph to E/F.

147 KHANDWA-DHULE I 400kV

PGCIL (Y) 08/04/2013;12:15 08/04/2013;13:13

A/T at Khandwa end only on R-E Fault in Zone-II due to some problem at Dhule MSETCL S/S.

148 KHANDWA-DHULE II 400kV

PGCIL (Y) 08/04/2013;12:15 08/04/2013;13:17

A/T at Khandwa end only on R-E Fault in Zone-II due to some problem at Dhule MSETCL S/S.


PGCIL (Y) 09/04/2013;6:57 09/04/2013;6:57

A/R Successfully at at both ends on transient Y-ph to E/F

150

SUGEN-VAPI 400kV

PGCIL (Y)

09/04/2013;07:59 09/04/2013;11:50

A/T due to R-Ph to E/F F/L - 103.7kM from Vapi & 0.3 kM from Suzen. Fault portion of line belongs to Torrent energy limited.

151 SATNA-BINA(PG) II 765kV

PGCIL (Y) 13/04/2013;18:59 13/04/2013;19:44

A/T on R-ph to E/F. Heavy rain & lighting observed in the area (persisting fault)

152

SATNA-BINA(PG) II 765kV

PGCIL (Y) 14/04/2013;16:00 26/04/2013;20:31

A/T on R & B Ph to Ph Fault due to Tower (A+3) found bend due to Heavy Wind Storm


PGCIL (Y) 14/04/2013;18:36 14/04/2013;19:07

A/T on B-ph to E/F at both ends (persisting fault)

154 VINDHYACHAL-SATNA IV 400kV

PGCIL (Y) 19/04/2013;17:02 20/04/2013;08:24

A/T on OV stage - I protection at Satna.

155 SATNA-BINA(PG) I 765kV PGCIL (Y) 19/04/2013;17:07 19/04/2013;17:42 A/T on OV stage - I

protection at Satna. 156 VINDHYACHAL-

JABALPUR II 400kV PGCIL

(Y) 20/04/2013;17:59 20/04/2013;18:29 A/T Due To Receipt of DT From NTPC VSTPP End

157 MUNDRA-LIMBDI I 400kV

PGCIL (Y) 22/04/2013;17:17 22/04/2013;20:03

A/T on Y-Ph to E/F (persisting fault)

158

MUNDRA-LIMDI II 400kV

PGCIL (Y) 22/04/2013;18:11 22/04/2013;20:30

A/T on D/T recived from CGPL Mundra due to PLCC Mal-operation at CGPL Mundra.

159 KAWAS-NAVSARI (PG GIS) II 220kV

PGCIL (Y) 24/04/2013;14:32 24/04/2013;16:20

A/T at Kawas end only due to opening of Jumper

160 JABALPUR-ITARSI II 400kV

PGCIL (Y) 28/04/2013;14:38 28/04/2013;15:47

A/T due to R ph to E/F due to fire in farm fields


Annexure-4

Status of implementation of recommendations of Report on Grid disturbance on 30th and 31st July in WR as on 04.06.2013

No. Time Subject/Description Action taken

Frame 9.1.1 1 Year There is a need to review protection

schemes. This Committee concurs with recommendation of previous enquiry committees that a thorough third party protection audit need to be carried out in time bound manner. This exercise should be repeated periodically and monitored by RPCs.

RPCs, CTU, STUsGETCO: 9 Number of S/Ss identified & completed through M/s Voltech Engg. MSETCL : 119 Number of S/Ss identified & completed. NTPC : 5 Number of S/Ss identified & completed. MPPTCL : 37 Number of S/Ss identified & completed. PGCIL :26 Number of S/Ss identified & completed. JP Bina/JPL: PGCIL to carry out PA CSPTCL :16 Number of S/Ss identified & completed. Rinfra :10 stations identified for PA through PRDC. Target for completion-30.06.13 NPCIL : Internal PA to be carried out by Feb-13. CGPL: PA carried out on 22/23.01.2013 through revolving group. WRPC : Revolving group formed, PA to be carried out based on requests received. Requests for PA received from NPCIL and CSPTCL.

9.1.2 Immediate

Till protection audit is taken up, there is need to take immediate review of zone-3 philosophy in particular. Techniques are available to modify characteristics of the relay so that it can distinguish between load encroachment and faults. These techniques and other alternatives should be explored immediately.

RPCs, CTU, STUsPower Swing MSETCL : All zones blocked for 2 Sec NTPC : All zones blocked for 2 Sec GETCO :zone-3 blocked as per CBIP 274 manual Load Encroachment Approach : Following two approaches are identified.(i) Shaping of Z-3 characteristics by

distinguishing between load and line angles wherever the relay supports this feature.

(ii) Z-3 adaptive protection by sensing the zero sequence component wherever the relay supports this feature.

(iii) CEA Criteria-Extreme loading may


be taken as 120% of thermal current loading limit at 0.9 pu voltage

In the 116th PCM utilities were requested to judiciously adopt the settings for Z-3 where ever the relay supports these features.

9.1.3 1 year The application of synchrophasor measurements from PMUs should be explored for protection systems. There is also an urgent need to deploy Special Protection System (SPS) in critical transmission elements. Also there is need to make already approved SPS operational.

RPCs, CTUPMUs under pilot project installed at Raipur, Bhadravati, Jabalpur, Itarsi & Sugen. PMUs at KSTPS, VSTPS and SSTPS is planned to be installed by WRLDC as discussed in the meeting held on 21.09.12. In Maharashtra 17 PMUs have been installed. URTDSM is being implemented by PGCIL. It is decided to procure 30% of PMU through indigenous sources as agreed in 35th SCM of WR. MSETCL : Location for 50 PMUs have been identified through IIT, Mumbai. To be integrated with URTDSM. CGPL : PMUs is planned to be installed by WRLDC

9.1.4 1 Month A complete independent audit of time synchronization of DRs, ELs and PMUs should be carried out

Generators, CTU, STUs Status of time synchronization awaited from STUs

9.2.1 1 Month Frequency band needs to be further tightened and brought close to 50 Hz. POSOCO may file an urgency application in Supreme Court for early resolution of the issue in view of the recent grid disturbances.

POSOCO

9.2.2 3 months

A review of UI mechanism should be carried out in view of its impact on recent grid disturbances. Frequency control through UI may be phased out in a time bound manner and Generation reserves/Ancillary services may be used for frequency control. Appropriate regulatory mechanism needs to be put in place for this purpose. POSOCO should take up the matter with CERC

POSOCO


9.3 Immediate

All STUs should immediately enable under frequency and df/dt based load shedding schemes. Central Commission should explore ways and means for implementation of various regulations issued under the Electricity Act, 2003. Any violation of these regulations can prove to be costly as has been the case this time. RPCs need to take up the matter for compliance. In case non-compliance persists, POSOCO should approach Central Commission.

STUs, RPCs, POSOCO Revised UFR and df/dt scheme implemented by all utilities. In case of WR getting isolated from rest of NEW grid to arrest high frequency operation and unplanned unit tripping few units have been identified for planned tripping at 51.5 Hz.

9.4 3 months

All out efforts should be made to implement provisions of IEGC with regard to governor action. Central Commission needs to look into ways and means to hasten implementation of provisions of IEGC including that on governor action. POSOCO need to take up the matter with Central Commission.

POSOCO197-No. of units eligible for RGMO 84- No. of units operating under RGMO. 13- No. of units exemption applied 100- No. of units in various utilities are yet to be made to participate in the RGMO Exemption not granted to any generator by CERC.

9.5.1 1 month POSOCO should take up with Central Commission the issue of inconsistency between Congestion regulation and the detailed procedure framed there under so that congestion due to forced outages and Unscheduled Interchange (UI) can be handled effectively

POSOCO

9.5.2 6 months

NLDC and each RLDC should have one real-time security desk in all the shifts to be manned by engineer capable of carrying out TTC calculations. To facilitate this, manpower at NLDC and RLDCs need to be enhanced with regulatory support to take care of financial aspects. Till this arrangement can be firmed up, various scenarios of outages could be built, which then

POSOCO


can be used by despatcher in real time. Faster algorithm for calculation of TTC may be adopted by the load despatchers to update it in real time under outage

conditions.

9.6 Immediate

Outage planning of inter-State and inter-regional transmission elements should be carried out in a coordinated manner at RPC fora (say Operation Co- ordination sub-committee of RPCs) in accordance with regulation 5 of Central Electricity Authority (Grid Standards) Regulation, 2010 and Section 5.7.1 of Indian Electricity Grid Code. In case need for emergency maintenance arises in between two meeting of Operation Co-ordination sub-committee, NLDC and RLDCs should allow such maintenance after carefully looking at prevailing system conditions under intimation to RPC

Secretariat

RPCsAlready discussed and agreed in OCC of WRPC. 1. Interstate lines are coordinated by RPC/RLDC in monthly OCCs 2. Interregional lines are coordinated by NLDC in consultation with RPCs/RLDCs This is implemented and being regularly monitored in OCCs of WRPC.

9.7 6 months

In order to avoid frequent outages/opening of lines under over voltages and also providing voltage support under steady state and dynamic conditions, installation of adequate static and dynamic reactive power compensators should be planned.

CEA, CTU, STUs10+17 reactors in various locations planned in WR and under various stages of implementation by PGCIL/GETCO/MSETCL.In 35th SCM, SATCOM which is modern technique for compensation of reactive power approved at six locations in WR.

9.8 6 months

The powers of Load Despatch Centres and Regulatory Commissions related to non-compliance of statutory/regulatory provisions including that for non- compliance of directions and non-payment of UI charges, need review. Appropriate amendments need to be carried out in the Electricity Act, 2003 after such

Ministry of Power, Govt. of India


review.

9.9.1 Immediate

The regulatory provisions regarding absorption of reactive power by generating units needs to be implemented

POSOCO

9.9.2 6 months

An audit of devices such as HVDC,TCSC, SVC and PSS should be done immediately toensure that their stability features are enabled. Further,exercise of PSS tuning should be planned andimplemented. Settings of these dynamic stabilizing devices shouldbe reviewed at appropriate intervals

CTU, STUs, Generators 23 generators PSS tuning completed. Telemetry data from TCSC/FSC not available to RLDC.

9.9.3 Immediate

Functioning of existing PMUs and availability of their output to RLDCs and accuracy of time synchronization should be monitored on daily basis and, if required, corrective actions should be taken on priority basis

CTU, POSOCOAll PMUs are working. Time synchronization issue.

9.10.1

1 year The synchrophasor based WAMS employing PMUs offer a wide applications for real time monitoring and control of the system, specially under the dynamic conditions. Adequate number of PMUs should be installed to improve the visibility and real time monitoring of the system. Further the applications related to the synchrophasor based wide area monitoring, protection and control should be embedded in the system

CTUPMUs on pilot project installed at Raipur, Bhadravati, Jabalpur, Itarsi. PMUs at KSTPS, VSTPS and SSTPS is planned to be installed by WRLDC as discussed in the meeting held on 21.09.12 to discuss occurrence at Sipat on 14.09.12. URTDSM is being implemented by CEA.

9.10.2

1 year Possibility of voltage collapse prediction, sensing global power system conditions derived from local measurements may be explored

RPCsA-eberle Relay installed at 400 kV Boisar (PG) s/s. In 110th PCM proposed at Jetpur, Bhilai, Aurangabad, Indore and Ponda s/s


9.11 6 months

In order to assess the system security in real time and assess the vulnerability condition of the system, dynamic security assessment need to be periodically carried out at the control centers. A proper review and upgradation of the state estimation procedure is required to improve the visibility and situational awareness of the system

POSOCO

9.12 Efforts should be made to design islanding scheme based on frequency sensing relays so that in case of imminent grid failure, electrical islands can be formed. These electrical islands can not only help in maintaining supply to essential services but would also help in faster restoration of grid

CEA, RPCs, POWERGRID, STUs, SLDCs and Generators 1.Mumbai, Ahmedabad , GTPS uran islanding schemes functional at present 2. Scheme for Bhopal city/ Bina Traction/JP Bina Power stn is under development. 3. All CPPs are planned for islanding at a

lower frequency than 48.8 hz i.e. final stage of UFR setting so that these stations are available for startup power.

4. APL-SPS, LANCO-SPS is already there. SPS for Agra- Gwalior, Zerda-Kankroli, Badod-Modak is planned. Units to be backed down in WR have been identified.

9.13.1 1 year

As National Grid is on the horizon, homogenization of Govt. of India, State Govts

system operation philosophy is need of the hour. The

present organizational set up of Load Despatch Centres

need to be reviewed. System operation needs to be

entrusted to Independent System Operator (ISO). In

addition, SLDCs should be reinforced and ring fenced

for ensuring functional autonomy 9.13.2

3 months

Training and certification of system operators need to be Govt. of India, State Govts

given focused attention. Sufficient financial incentives

need to be given to certified system operators so that

system operation gets recognized as specialized activity


9.14 2 years Intra-State transmission system needs to be planned and strengthened in a better way to avoid problems of frequent congestion

STUs

9.15.1

6 months

Appropriate amendments should be carried out in Grid CEA

Connectivity Standards to restrain connectivity of a

generating station or a transmission element without

required communication and telemetry facilities.

9.15.2 1 year

The Communication network should be strengthened by putting fibre optic communication system. Further, the Communication network should be maintained properly to ensure reliability of data at Load Despatch Cenres

CTU and STUsApprovals by WRPC

• Addl. 2672 Kms of OPGW, 14kms of OFC along with wideband communication equipment of adequate capacity for setting up of back-up SLDC at Govindpura, Bhopal, connectivity of Sub-LDC Gandhinagar and Sub-LDC Jetpur to SLDC Vadodara (Gotri) on OFC with suitable end equipments.

• Existing communication equipments (SDH 37nos. & PDH 72nos.) to be replaced at the cost of 3.89 crores

• Installation of PABX System at SLDCs of Western Regions, WRLDC and NLDC

9.15.3

3 months

RTUs and communication equipments should have CTU and STUs

uninterrupted power supply with proper battery backup

so that in case of total power failure, supervisory control

and data acquisition channels do not fail 9.15.4

6 months

In case of existing generating stations or transmission RPCs, POSOCO

elements without telemetry facility, the same should be

New stations are mandated for data transmission through

put in place at the earliest. If prolonged operation telemetry before commissioning.

without telemetry continues, POSOCO should approach

Central Commission


9.16 1 year Large variations are observed in time taken for initiation of unit start up (Boiler light up) by the stations after availability of start-up power and also for start ups/light up of subsequent units. While subsequent start-ups were very fast (10-20 minutes) in some of the units, in other cases they took considerably longer time – several hours. Reasons for the delays in attempting first start-up and subsequent start-ups may be examined by the utilities in consultation with CEA. A standard procedure for preparatory activities and sequence of start up may be put in place by the stations to restore units as early as possible particularly in contingencies.

CEA, Generating Utilities and RLDCs

9.17 3 months

At inter-State level, the entire landscapehas changed CEA

over past few years. With de-licensing of generation and

provision of open access in Electricity Act, 2003 and

development of organized electricity markets, lot of

generation is coming in the form of merchant generation.

Four out of the five regions have been integrated and

formation of National Grid is on the horizon. Under such

scenario, there is need review the Transmission Planning

criteria. 9.18 1 year There is need to reinforce system study

groups in power sector organisations to analyse the system behaviour under different network status/ tripping of lines/outage of generators. Where these do not exist, these should be created

CEA, CTU and STU


9.19 1 month It was felt that a separate task force may be formed, involving experts from academics, power utilities and system operators, to carry out a detailed analysis of the present grid conditions and anticipated scenarios which might lead to any such disturbances in future. The committee may identify medium and long term corrective measures as well as technological solutions to improve the health of the grid

MOP, CEA

9.20 1 year For smooth operation of grid systems, it is absolutely important that all the power generating and distributing stations are connected on a very reliable telecom network. (i) A proper network may be built up preferably using MPLS(multy protocol label switching) which is simple, cost effective and reliable. In remote place where connectivity is a problem, the stations can use dedicated fibre cable from the nearest node (ii) Since POWERGRID has its own fibre optic cables, practically covering all major nodes and power stations, a proper communication/IT network may be built using dedicated fibres to avoid any cyber attach on the power system.

CTUs, STUs

Documents

Baart sarkar Government of India kond`Iya a ivaVut p`aiQakrNa · · 2013-07-0533) Addl General Manager, WRTS-II, ... while taking the shutdown on 220/132 kV, ... There is no Bus