Baart sarkar Government of India kond`Iya ivaVut p ... · with 220 KV Dahej, 220/66 KV 50 MVA T/F and 220 KV Bus Coupler at 220kV Wagra S/S. All the above feeders were connected to

Baart sarkar Government of India kond`Iya ivaVut p`aiQakrNa

Central Electricity Authority piScama xao~Iya ivaVut saimait

Western Regional Power Committee ef -3, emaAayaDIsaI xao~, AMQaorI (pUva-), mauMba[- - 400 093

F-3, MIDC Area, Andheri (East), Mumbai - 400 093

Aa[- esa Aao : 9001-2000 ISO : 9001-2000

dUrBaaYa Phone: 022- 28200194, 28200195; 28200196; fO@sa Fax : 022 – 28370193 Website : www.wrpc.gov.in E-mail : [email protected]

¬ ¿̧.:œ¸® ½̧¢¨¸¬¸/£®¸μ¸/£®¸μ¸ ¬¸.ˆÅú 106¨¸ì ¤¸¾“ˆÅ /2009/ ¢™›¸¸¿ˆÅ: No.: WRPC/Prot./ 106th PCM/2009/ 8776 Date:17th August 2009. ¢¨¸«¸¡¸ : œ¸® ½̧¢¨¸¬¸¢Ÿ¸¢÷¸ ˆÅú £®¸μ¸ ¬¸¢Ÿ¸¢÷¸ ˆÅú 106 ¨¸ì ¤¸¾“ˆÅ ˆÅ¸¡¸Ä¬¸»�¸ú— Sub. : Agenda of 106th WRPC, Protection Committee Meeting.

ƒ¬¸ œ¸°¸ ˆ½Å ¬¸¸˜¸ œ¸®¸½¢¨¸¬¸¢Ÿ¸¢÷¸ ˆÅú 106 ¨¸ì £®¸μ¸ ¬¸¢Ÿ¸¢÷¸ ˆÅú ¤¸¾“ˆÅ, �¸¸½ ¢ˆÅ ¢™›¸¸¿ˆÅ 1 evaM 2 isatMbar 2009 kao ha^Tola firyaasa laaoNaavalaa maoM ½ 10.30 ¤¸�¸½ ‚¸¡¸¸½¢�¸÷¸ ˆÅú �¸¸› ½̧ ¨¸¸¥¸ú í¾, ˆÅú ˆÅ¸¡ Ä̧¬ »̧�¸ú ¬ ¿̧¥¸Š›¸ í¾ — £®¸μ¸ ¬¸¢Ÿ¸¢÷¸ ˆÅú 106 ¨¸ì ¤¸¾“ˆÅ ˆÅú ˆÅ¸¡¸Ä¬¸»�¸ú œ¸®¸½¢¨¸¬¸ ˆÅú ¨ ¾̧¤¸¬¸¸ƒ’ Ÿ ½̧¿ ž¸ú „œ¸¥¸¤š¸ í¾ — Saama 06:30 bajao ½ œ¸ ®¸½ ¢¨¸ ¬¸, ef -3, emaAayaDIsaI xao~, AMQaorI (pUva-), mauMba[- sao ha^Tola firyaasa laaoNaavalaa ko ilayao basa ka p`baMQa ikyaa gayaa í¾ —

ˆ¼Åœ¸¡¸¸ ¤¸¾“ˆÅ Ÿ¸½¿ ž¸¸Š¸ ¥¸½¿ — Please find enclosed herewith Agenda of 106th Protection Committee Meeting of WRPC, to be held on at

10:30hrs on 1st and 2nd September 2009 at Hotel Fariyas Resort Lonawala. Transport arrangement to pick up the participants from WRPC Office, MIDC Area, Near SEEPZ bus stand, Andheri (E), Mumbai to Hotel Faiyas Resort Lonawala has been made at 18:00hrs of 31st August 2009. Participants attending the meeting are requested to contact following coordinating officers for further co-ordination.: Name Designation Mobile No /Fax No. Phone No. e-mail address Sh.T. Murali Krishna

Chief Manager 09223327501/ 022 66687088

022 66687081,82,83 [email protected]

Sh. Girish T. Jawale

Asst. Manager 09223311419/ 022 66687088

022 66687081,82,83 [email protected]

Agenda of 106th PCM is also available on WRPC website (i.e.www.wrpc.gov.in).

Kindly make it convenient to attend the meeting.

ž¸¨¸™ú¡¸ / Yours faithfully, ‚›¸º¥¸Š›¸ˆÅ : ¡¸˜¸¸½œ¸¢£ Encl: As above (ema Aar saIMga/M.R.Singh) ‚š¸ú®¸μ¸ ‚¢ž¸¡¸¿÷¸¸ (£.) / Superintending Engineer (P.)

AGENDA FOR THE 106th PROTECTION COMMITTEE MEETING

Item No.1: Confirmation of Minutes of 105th Protection Committee Meeting.

Minutes of 105th PCM, held on 18th June 2009 at WRPC Mumbai, were circulated

vide WRPC letter no. Prot./105 PCM/2009/WRPC-6994 dated 06th July 2009. Comments

have been received from WRTS-II, PGCIL regarding compliance of Annex.-4, and

requested to revise the Column III, Row iii (D) of Annex.-4 as

“POWERGRID informed that they have implemented Analogue Triggering of

DR in all the Substations (O/C and O/V)”

Letter received from PGCIL is enclosed at Annex.-1.

Committee may discuss and the minutes may please be confirmed.

Item No.2: System disturbances

2.01: System disturbances in GETCO/GSECL system

(i) System disturbance at 220 kV Tapper S/S in GETCO system on 02-05-2009.

On 02-05-2009 at 10:05 hrs., the 220 KV Tappar- Nanikhakhar-1, 220 KV

Tappar- Sivlakha- 1, 200 KV Tappar- Sivlakha- 2 feeders tripped on Zone 2, B

phase to earth from remote ends.

The 220 KV Tapper- Nanikhakhar-2 was under planned shut down for

maintenance work. During measurements of the breaker timings, through the

breaker timing kit, the isolator was made ON to defeat the interlock by

ignorance/human error of the working Engineers/ staff. The kit got charged

through breaker timing kit wires. It created fault of high resistive nature burning

the kit & wires. All the lines connected to Tappar S/S tripped from remote ends in

zone-2, since the bus isolator was not fully closed and hence the bus bar scheme

did not operate resulting in no power at 220 KV Tapper S/S from 10.05 to10.20

hrs.

GETCO may please submit restoration details.

Report received from GETCO is enclosed at Annex- 2.01 (i).

Committee may discuss.

(ii) System disturbance at 220 kV Wagra S/S in GETCO system on 31-05-2009.

On 31.05.2009 at 06:35hrs., 220 KV Wagra-Haldarwa line tripped along

with 220 KV Dahej, 220/66 KV 50 MVA T/F and 220 KV Bus Coupler at 220kV

Wagra S/S.

All the above feeders were connected to Bus A and Bus B was charged

through Bus Coupler with out any feeder connected to it. The newly

commissioned AREVA make Bus bar protection Scheme operated for a through

fault of transient nature on the 220 KV Wagra-Haldarwa line.

All the feeders were restored by 07:20hrs, except 220 kV Wagra-Haldarwa

feeder which was restored by 11:10hrs.

Report received from GETCO is enclosed at Annex- 2.01 (ii).


(iii) System disturbance at 220kV Vav S/S in GETCO system on 23-06-2009.

On 23.06.09 at 09:40hrs, all the feeders connected to 220 KV Bus A and

B/C breaker tripped while charging the 220/66 KV 100 MVA T/F -1 on 96 relay

due to operation of LBB of the T/F-1 at 220kV Vav S/S. The 100 MVA T/F – 1

tripped on LBB and E/F along with 96 relay.

The 100 MVA 220/66 KV transformer was under planned shut down. The

transformer tripped on Earth Fault due to high inrush current, during charging.

The LBB of this feeder operated due to delayed tripping of R phase pole of the

transformer breaker. The PDR also operated. After detailed investigation of

breaker, it was found that the delayed tripping of R-Ph pole of transformer was

due to weak/faulty Trip Coil-1.

All the tripped feeders were restored by 10:48 hrs, except T/F-1 which

was restored at 19:50hrs after replacing the R Phase TC-1 of 100 MVA T/F No-1

breaker.

Report received from GETCO is enclosed at Annex- 2.01 (iii).


(iv) System disturbance at Gandhinagar TPS in GSECL system on 07-05-2009.

On 07.05.2009 at 03:50hrs, B-phase PT of 220kV Bus-II stage-I, got busted

and fire took place at Gandhinagar TPS. The Bus Bar protection of Bus-II operated,

due to which all the lines, T/F’s and Generators connected to Bus-II tripped.

During yard inspection the post insulator (PT side) of B phase isolator was

found damaged and fell down along with the isolator contact arm.

GSECL may please submit restoration details.

Report received from GSECL is enclosed at Annex- 2.01 (iv).


(v) System disturbance at Sikka TPS in GSECL system on 04-06-2009.

On 04.06.2009 at 15:00hrs, a sound of flashover was heard and

simultaneously Bus Bar differential protection of 132 kV Bus A operated, thereby

tripping all the lines, T/F’s and generators connected to Bus A at Sikka TPS.

132kV Dhrol and 132kV Naghedi lines connected to Bus-B, tripped from

remote ends on distance protection. Inspection of 132kV switch yard was done and

also PID of 132kV Bus and Bus Coupler tension string was carried out. However

no abnormality was observed.

Normalcy was restored by 17:05hrs..

Report received from GSECL is enclosed at Annex- 2.01 (v).


2.02: System disturbance in MPPTCL/MPPGCL system

(i) System disturbance at 400 KV S/S Nagda in MPPTCL system on 23-05-2009.

On 13.05.2009 at 22:45hrs, B phase CT of SCT make bearing Sr.No.2005/376

of 220kV Nagda Ratlam-I feeder failed at 400kV Nagda S/S. 220 KV Ratlam-I feeder

was connected on Bus-I. Due to failure of this CT the ER make 220 KV Main-I Bus-

bar protection scheme CSC-150 operated thereby tripping all the feeders connected to

Main-bus-I and isolated the fault in 52msecs.

Normalcy was restored by 07:55hrs.

Report received from MPPTCL is enclosed at Annex- 2.02 (i).

Committee may discuss failure of the CT.

2.03: System disturbance in MSETCL/MSEGCL system

(i) System disturbance at 220kV GTPS Uran S/S in MSETCL system on 19-04-

2009.

On 19.04.2009 at 22:45hrs, the B-ph line PT of 220kV Uran-Apta feeder got

busted at 220kV Uran S/S. The 220kV Bus bar zone-2 operated and tripped all the

connected feeders to Bus-II and Bus-I.

The line PT & CTs are installed very near in line bay between line & transfer

bus isolator. The PT was commissioned on 18.04.2009. The busting of the PT

created a bus fault. Due to non tripping of the Bus Coupler, the LBB protection of

the Bus Coupler operated resulting in tripping of all the feeders connected to

220kV Main Bus-I. 220kV Uran-Apta-II tripped from remote end in Zone 2 DPS.

Normalcy was restored by 09:06hrs of 20.04.09, except Unit#7, which was

restored at 01:17hrs of 21.04.09.

Report received from MSETCL is enclosed at Annex- 2.03 (i).


(ii) System disturbance at 400kV Karad S/S in MSETCL system on 19-05-

2009.

On 19.05.2009 at 12:03hrs, the B phase jumper of 220kV Bus Coupler got

opened resulting in tripping of 400kV lines at 400kV Karad S/S.

There was a loss of load of the order of 850MW in the Kolhapur region of

Maharashtra and Goa states.

All the 400kV lines and ICT’s were restored by 13:54hrs., and the 220kV

network was restored by 14:00hrs.

MSETCL may please submit a detail report.

Preliminary report received from LD Kalwa is enclosed at Annex- 2.03 (ii).


2.04: System disturbance in NPCIL system

(i) System disturbance at 2x220MW KAPS ATPS in NPCIL system on 02-04-

2009.

On 02.04.2009 at 13:26hrs, all the 220kV feeders connected to Bus Bar-1

tripped, on Bus Bar differential protection at KAPS ATPS.

During yard inspection a section of Y-phase Bus bar was found bent at the

extreme end of the 220kV Main Bus-I. Some of the post insulators were found

broken with a slight soot on the surface of Main Bus Bar tube and Bus support

clamps. The R phase bay Bus of Bay No.13 (Haldarwa No.1 feeder) was also found

bent with Bus support insulator clamp broken and Circuit Breaker end support

clamp deformed.

220kV KAPS-Vapi#1 and KAPS-Vav#1 charged on 02.04.09, 220kV

KAPS-Haldarwa#1 & 2 charged on 04.04.09 and 220kV Bus Bar#1 normalised on

06.04.09.

Report received from NPCIL is enclosed at Annex- 2.04 (i).


2.05: System disturbance in PGCIL system

(i) System disturbance at 400kV Jabalpur S/S in PGCIL system on 12-05-

2009.

On 12.05.09 at 14:06hrs, the B phase to Earth fault appeared on 400kV

Vindhyachal-Jabalpur#1 line, but due to persisting fault, it led to 3-ph tripping of

the line. Simultaneously the Y-ph grading capacitor (line side) of the Tie bay

breaker of the 400kV Vindhyachal Jabalpur #1 line failed at Jabalpur S/S.

During tripping of 400kV Vindhyachal-Jabalpur#1 line, the Y-ph grading

capacitor of the tie bay of 400kV Vindhyachal-Jabalpur#1 line (line side) got

blasted. The Bus Bar#2 protection operated at Jabalpur S/S. However, due to arcing

between Y & B phase, the fault was sensed by other feeders also, namely 400kV

Vindhyachal-Jabalpur#2, 400kV Jabalpur-Itarsi#1&2 and tripped on operation of

Main-II protection. The 400kV Vindhyachal-Jabalpur # 3 & 4 and Jabalpur-Itarsi

#3 & 4 tripped on operation of over voltage stage-I protection.

All the lines were restored by 17:55hrs of 12.05.09.

Report received from PGCIL, WRTS-II is enclosed at Annex-2.05 (i)


(ii) System disturbance at 400kV Rajgarh S/S in PGCIL system on 17-06-

2009.

On 17.06.09 at 07:14hrs, 400kV Rajgarh-SSP # 1 tripped on R ph to Earth

fault due to snapping of R-phase conductor. After approximately 1 sec., Auto

Reclosure attempt took place, but the fault was persisting resulting in 3-phase

tripping of the line. The Bus Bar protection of Bus-I also operated at the same time,

leading to tripping of 400kV Rajgarh-Nagda # 2 line.

The Bus Bar protection scheme is of ABB make. The matter has been taken

up with ABB for operation of Bus Bar protection on through fault.

All the lines were restored by 11:00hrs of 17.06.09.

Report received from PGCIL, WRTS-II is enclosed at Annex-2.05 (ii)


ITEM NO. 3: Tripping of lines / ICTs:

The incidences of tripping of lines and ICTs during the period 01-04-2009 to

30-06-2009 are enclosed at Annexure –3.


ITEM NO. 4: Protection related recommendations on Grid Disturbances in Western

Regional Grid on 25.2.2007 at 1634 hours and 28.2.2007 at 13:11 hours:

Protection related recommendations of the Enquiry Committee on Grid

Disturbances in Western Regional Grid on 25.2.2007 at 1634 hours and 28.2.2007 at 13:11

hours were discussed during the 105th WRPC PCM held at WRPC Mumbai. The status as

reported in 105th PCM regarding implementation of the recommendations is placed at

Annexure-4.

Committee may discuss and constituents may intimate the present status regarding

implementation of recommendations.

ITEM NO. 5: Other points:

5.01: Configuration of direct trip PLCC protection scheme for 220kV lines

emanating from PGCIL S/Ss to utilities.

PGCIL vide their letter No WRTS/O&M/R/141/526 Dt.06.05.09 have informed that

the commissioning of direct trip PLCC scheme is still pending from CSEB end on the

220kV Urla, 220kV Bhilai, 220kV Bhatapara, 220kV Khedamara, 220kV Surkhi and

220kV Suhela lines emanating from Raipur and Bhatapara S/S of Powergrid.


5.02: Testing rectification of the protection schemes at 220kV Ponda S/S:

PGCIL vide their letter No WRTS/O&M/R/141/526 Dt.06.05.09 have informed

that on 31.01.09, 03.03.09 and 10.04.09 tripping occurred on 220kV Mapusa-Ponda line-2.

On all the occasions the fault was beyond the line and the respective protection schemes at

Ponda S/S did not clear the fault. The fault was sensed by protection at Mapusa S/S of

POWERGRID in zone-2/zone-3 timings and the fault current was fed from Mapusa S/S for

that much duration.

During the 105th meeting Goa Electricity Department representative told that

necessary corrective actions would be taken at their end and the compliance would be

communicated by the next PCM

Goa Electricity Department may please inform the status.

5.03: Revision of settings of df/dt UFLS relays in WR grid

In continuation with the discussion in the 104th meeting, it was decided that the data

received regarding mal operation of the df/dt relays would be analyzed by WRPC.

The details of the mal-operations of df/dt relays from GETCO and MSETCL were

received by WRPC. Other constituents may also please submit the data regarding mal

operation of the df/dt relays.


5.04: Non-availability of Event Logger at 400kV state owned sub-stations at

Nagda, Indore, Bina Padghe, Kolhapur, Koradi, Chandrapur, Dhule and

Bhilai.

During 104th PCM, PGCIL had informed that Event Loggers at some of the 400kV

state owned Sub stations, namely Nagda, Indore, Bina of MPPTCL, Padghe, Dhule,

Kolhapur, Koradi, Chandrapur of MSETCL and Bhilai of CSPTCL are not provided.

PGCIL have requested for early installation of Event Loggers at these stations.

MPPTCL representative in earlier meetings had informed that event loggers for

Nagda, Indore and Bina S/S were under procurement process. However the representative

present for 105th PC meeting told that there is no plan of procurement of event loggers for

the above S/S’s. MPPTCL was requested to initiate the process of procurement at the

earliest and inform the progress in next PCM.

MSETCL representative in the 105th PCM informed that event logger for Padghe

has been commissioned, and the event loggers for Dhule & Kolhapur would be

commissioned by Dec.09. Further the event loggers at Koradi, Chandrapur and

Khaparkheda have been provided, but unit outages from the generating stations is awaited

for incorporating the events of generating units. MSETCL and MSPGCL representatives

agreed to co ordinate for the same.

Present status of installation of Event Loggers at above S/S, may be intimated.

5.05: Pending SOE connections and erroneous data in SCADA.

The matter was first discussed in the 102nd PCM, with reference to the pending

SOE connections it was opined that the constituents should confirm the availability of

hardware at RTU’s for incorporating the extension of MTR contacts to the SOE inputs of

the RTU, in addition to the CB contacts which are also required to be transmitted.

During 105th PCM, committee felt that, WRLDC may circulate the list of those

locations from where erroneous data is received and the locations where SOE

connections are yet to be established at the earliest so that corrective actions could be

taken up by constituents and the progress of the same could be monitored.

WRLDC may intimate the progress.

5.06: Review on the existing protection manuals and creating uniformity in the

settings of the modern protection relays.

It was decided in the 103rd PCM that the protection manual prepared by WREB and

referred by the protection engineers is around 10 years old and needs to be reviewed in line

with the present relaying technology. A copy of the WREB protection manual was

circulated amongst the members of the PCM vide letter No.Prot./Prot.Manl/2009/WRPC-

3829 Dtd. 21.04.09.

The members are requested to forward their comments to WRPC at the earliest on

Chapter-I “Transmission Line Protection” of the WREB protection manual so that the

same can be taken up for discussions, in this meeting.

Committee may discuss the comments of the members on Chapter-I

“Transmission Line Protection” of the Protection Manual.

5.07: Problem in Bus bar protection scheme at Korba (W) CSPTCL S/S.

NTPC vide their letter KS/EM/ETL/2405/615109/285 Dtd.05.05.09 have informed

that NTPC Korba and CSPTCL Korba(W) substations are connected with a 400kV line of

line length 14Km. On 04.05.09 at 02:51hrs bus fault occurred (one of the CT of inter

connecting transformer blasted) at CSPTCL end. The NTPC Korba- CSPTCL Korba (W)

line tripped in zone-2 from NTPC Korba end, thus feeding the fault current of around

14KA for the timing of zone-2. Inter trip or direct trip signal was also not received from

Korba (W) S/S. Similar fault had occurred at CSPTCL Korba (W) S/S on 09.09.08 at 11:48

hrs also and was fed for zone-2 timing from NTPC Korba S/S.

CSPTCL may intimate the status of the corrective actions.

5.08: Proposal of replacement of equipments in second phase under R & M by

WRTS-I POERGRID

POWERGRID vide their letter WRTS-1/O&M/R/142/767 Dtd.19/06/2009, have

proposed to replace following equipments;

(i) Old PLCC panels Type ETI, NSD60-30nos at an estimated cost of Rs.1.5

Crore,

(ii) Replacement of Battery bank at Raipur-4nos, Bhadravati both AC and DC-

10nos, Mapusa-4nos., Boisar-4nos., at an estimated cost of 2Crore.

(iii) Replacement of switchyard equipment (CT’s & CVT’s) due to higher fault

level near Bhilai S/S at an estimated cost of 1.2Crore.

(iv) Replacement of Transformer oil of 13 nos. of converter transformer at HVDC

Bhadravati at an estimated cost of Rs.6Crore

(v) Procurement of long term HVDC spares at an approximate cost of 10Crores

(vi) Procurement of Insulator Washing Equipments with vehicle at an approximate

cost of Rs.1Crore

Letter received from PGCIL WRTS-I is enclosed at Annex-6.08.


5.09: Line reactor at Sugen:

NTPC have informed that a 400kV Jhanor-Padghe line of 290km length was having

50 MVAR reactors installed at both ends. Subsequently the line was made LILO at Vapi,

without line reactor at Vapi end and the 400kV Jhanor-Vapi line length reduced to 167km.

Further the 400kV Jhanor –Vapi line was made LILO at Sugen (near Surat) without line

reactor at Sugen end. The line length of 400kV Jhanor-Sugen line further reduced to 65km.

Committee may discuss whether line reactor at Jhanor end should be in

service with a line length of 65km and no reactor at remote end.

ITEM NO. 6: System disturbance at 400 kV VSTPS Vindhyachal S/S in NTPC

system on 22-07-2008

As discussed during 102nd PCM, a study group comprising of members from

WRPC, WRLDC, VSTPS, Powergrid, GSECL and MSETCL was formed by Member

Secretary, WRPC to look into the matter in detail and analyze the incidence and come up

with remedial measures to avoid such occurrences.

The Study Group has submitted its report and the same was circulated vide

letter No. WRPC/Prot./Vindya/2008-09/5891 Dtd.03.06.09.


ITEM NO. 7: Date and Venue of the next meeting.

ANNEXURE-3

TRIPPINGS OF LINES / ICTS

Sr. No. NAME OF S/S Name of line/ICT SYSTEM /Provision

of A/R (Yes/No)

Tripping Restoration REASON

Date Time Date Time 3.01 400kV Jabalpur 400kV Jabalpur-

Itarsi#3 PGCIL (Y) 01.04.09 0:37 01.04.09 0:37

A/R successful on Y-N transient fault.

3.02 400kV Padghe 400kV Padghe-Bableshwar-I MSETCL

(Y) 01.04.09 4:09 01.04.09 5:09

R-E, Zone-1 fault. Patrolling done no fault found Line tripped from both end. Transient nature of fault

3.03 400kV Nagda 400kV Nagda-Dehgam#1 PGCIL

(Y) 01.04.09 19:23 01.04.09 20:48 Mal operation of PRD at Dehgam.

3.04 400 KV Korba 400 KV Korba-Bhilai # 1 PGCIL

(Y) 04.04.09 11:42 04.04.09 11:49 Line tripped from Korba end. Wiring problem, new main breaker commissioning

3.05 400kV Padghe 400kV Padghe-Lonikand MSETCL

(Y) 06.04.09 9:01 06.04.09 10:04 Bus fault at Lonikand end. Linetripped at Padghe end on receipof D/T.

3.06 400kV C'pur 400kV C'pur-Parli#1 MSETCL (Y) 06.04.09 12:04 06.04.09 12:04

Transient Y-N fault. A/R successful at both ends.

3.07 400kV Indore 400kV Indore-Asoj#1 PGCIL

(Y) 06.04.09 13:11 06.04.09 14:00 Transient R-N fault.

3.08 400kV Koradi 400kV Koradi-Akola MSETCL

(Y) 06.04.09 16:29 06.04.09 18:51 Transient B-N fault.

3.09 400 KV Boisar 400 KV Boisar-Padghe PGCIL

(Y) 08.04.09 17:50 08.04.09 18:06 Line tripped due to Direct Trip received from Padghe end due to DC earth leakage at Padghe.

3.10 400 KV Raipur 400 KV Raipur-Sipat # 1 PGCIL

(Y) 08.04.09 20:26 08.04.09 21:09 Line tripped on Y-E fault. F.L=71. 5 Km from Raipur

3.11 400kV Khadwa 400kV Khadwa-Rajgarh PGCIL

(Y) 09.04.09 6:33 09.04.09 6:38 O/V at Rajgarh S/S.


(Y) 09.04.09 00:16 09.04.09 01:51 Line tripped on Y-E fault. F.L=76 Km from Raipur


(Y) 09.04.09 01:51 09.04.09 02:01 Line tripped on Y-E fault. F.L=76 Km from Raipur.

3.14 400 KV Raipur 400 KV Raipur-Bhatapara PGCIL

(Y) 09.04.09 01:51 09.04.09 02:46

Line tripped during the charginof 400kV Raipur-Sipat # 1 due to maloperation of Tie LBB relay.

3.15 400 KV Raipur 400 KV Raipur -Raigarh # 1 PGCIL

(Y) 09.04.09 04:18 09.04.09 04:18 Line Auto Reclosed on R-phase, 31.5 Km from Raipur.



3.17 400kV Gandhar 400kV Gandhar-Dehgam#2 PGCIL

(Y) 11.04.09 15:21 11.04.09 15:56 Persisting R-N fault.

3.18 220 KV Korba(E)

220 KV Korba(E) - Budhipadar # 3 PGCIL

(Y) 12.04.09 06:48 12.04.09 07:52 Line tripped on C-Ph to Earth fault.

3.19 220 KV Korba(E)

220 KV Korba(E) - Budhipadar # 3 PGCIL

(Y) 12.04.09 21:34 13.04.09 01:25 Line tripped on C-Ph to Earth fault.

3.20 400 KV Kasor 400 KV Kasor-Chorania GETCO

(Y) 13.04.09 15:44 13.04.09 15:50 B-Ph. CVT failed at Chorania S/s end.

3.21 400 KV Kolhapur

400 KV Kolhapur - Mapusa # 1 PGCIL

(Y) 13.04.09 16:38 13.04.09 16:48 Line tripped on Rph - Earth fault at 79.26 kM from Mapusa

3.22 400 KV Kasor 400 KV Kasor -Gpec GETCO

(Y) 15.04.09 10:25 15.04.09 10:40 Mal operation of PLCC at GPEC end.

3.23 400kV Jabalpur 315MVA ICT#1 PGCIL (Y) 15.04.09 14:07 15.04.09 15:12

Backup protn optd at 220kV MPPTCL S/S

3.24 400kV Itarsi 400kV Itarsi-Indore#1 PGCIL (Y) 19.04.09 13:40 19.04.09 15:12

Bus Bar Protection operated at MPPTCL Indore S/S.

3.25 400 KV Korba 400 KV Korba-Vindhyachal # 1 PGCIL

(Y) 21.04.09 13:02 21.04.09 18:26

Line tripped on R-Phase to eartfault due to Tree caught fire near NTPC,Vindhyachal S/S boundary.

3.26 400 KV Asoj 400 KV Asoj-Indore 2 GETCO

(Y) 23.04.09 17:35 23.04.09 18:02 Line reactor differential trip at indore S/s.


Persisting Y-N fault.

3.28 400 KV Boiser 400 KV Boiser - Vapi PGCIL

(Y) 24.04.09 11:33 24.04.09 11:33 Line auto reclosed sucessfullyon B - Phase to earth fault. F/L=61.1km from Boiser end.




(Y) 26.04.09 9:45 26.04.09 9:45 Transient R-N fault. A/R successful at both ends.

3.31 400kV Koradi 400kV Koradi-Akola

MSETCL (Y) 27.04.09 6:02 27.04.09 7:06

L/O trip on receipt of DT signaat Koradi end. The line tripped on O/V stage-I (setting 110% 5sec.) at Akola end & DT was sent to Koradi

3.32 400kV Satpura 400kV/220kV ICT

MPPTCL 30.04.09 20:30 01.05.09 2:24

ICT tripped from 400kV & 220kV sides on B/U instantaneous Y phase, due to failure of Y ph. CVT of 220kV Sarni-Pandhurna line.

3.33 400 KV Korba 400 KV Korba - Bhilai # 2 PGCIL

(Y) 30.04.09 10:10 30.04.09 10:36 Line tripped at Bhilai end

3.34 400kV Satna 400kV Satna-V'chal#1 PGCIL

(Y) 03.05.09 5:36 03.05.09 20:37 O/V optd., at VSTPP end.


Persisting B-N fault.

3.36 400kV Padghe 315MVA, 400/220kV ICT-2 MSETCL

(Y) 04.05.09 16:54 04.05.09 17:43 Diff protection operated. On inspection 33kV cable found damaged.

3.37 400 KV Korba 400 KV Korba - Korba (W)

PGCIL (Y) 04.05.09 02:51 04.05.09 04:50

Line tripped at Korba end on B/B protection operated at Korba (W),due to failure of 400kV Rph CT of ICT at Korba (W).

3.38 400 KV Bhilai 400 KV Bhilai-Korba # 1 PGCIL

(Y) 05.05.09 10:01 05.05.09 10:25 Line tripped due to receive of Direct Trip command from Korba end.PLCC maloperation

3.39 400 KV Bhilai 400 KV Bhilai-Koradi

PGCIL (Y) 05.05.09 10:01 05.05.09 10:25

Line Tripped due to Direct Tripreceived from Korba end, as Korba-1 & Koradi line are terminated in the same dia at Bhilai.Main Bkr. of Koradi linewas out at Bhilai

3.40 400kV Kharghar

315MVA, 400/220kV ICT-1 MSETCL

(Y) 06.05.09 15:55 06.05.09 18:48 ICT tripped on the operation ofPRV. On inspection PRV switch found faulty

3.41 400 KV Wardha 400 KV Wardha - Akola #1 PGCIL

(Y) 07.05.09 07:04 07.05.09 10.14 Line tripped on over voltage.

3.42 765 KV Seoni 765 KV Seoni - Wardha # 1 PGCIL

(Y) 07.05.09 07:04 07.05.09 08:30 Line tripped on Over VoltageProtection Stage - 1.

3.43 400 KV Korba 400 KV Korba - Bhilai # 1 PGCIL

(Y) 07.05.09 16:26 07.05.09 16:45

Line Tripped only at Bhilai endon receipt of Direct trip signal from Korba end. PLCC mal opeartion

3.44 400 KV Ranchi 400 KV Ranchi - Sipat # 1

PGCIL (Y) 08.05.09 18:00 08.05.09 18:40

Line successfully auto-reclosedfrom Ranchi end on R - E transient fault at 115 Km from Ranchi, but tripped at Sipat endonly

3.45 400kV Kalwa 400kV Kalwa-Padghe-1

MSETCL (Y) 09.05.09 14:05 09.05.09 14:58

Y-E, Zone-2 fault. While carrying out hot line washing, Y-ph conductor snapped the insulator resulting the flashover of Y-ph conductorat 51.1KM from Kalwa end

3.46 400 KV Raipur 400 KV Raipur-Bhilai # 1 PGCIL

(Y) 10.05.09 04:09 10.05.09 05:05 Line triped on Overvoltege stage-1 protection. CVT problem

3.47 400kV Seoni ICT # 1 (400/220KV) at Seoni

PGCIL (Y) 11.05.09 22:00 12.05.09 00:27

ICT tripped on earth fault protection along with tripping o220KV Seoni - Seoni # 1&2 lines (MPSEB) on line fault as fault was not cleared in 220KVlines.

3.48 400kV Nagothane

400kV Nagothane-Padghe-2 MSETCL

(Y) 12.05.09 4:40 12.05.09 12:33 R-E, Zone-2 fault. Earthwire found broken at 116KM from Nagothane end.

3.49 400 KV Wardha 400 KV Wardha - Akola # 1 PGCIL

(Y) 12.05.09 13:13 12.05.09 13:35

Line tripped at Wardha end only, on receipt of Direct trip command due to PLCC maloperation.


(Y) 12.05.09 15:24 12.05.09 16:07

Line tripped at Wardha end only, on receipt of Direct trip command due to PLCC maloperation.





3.53 400kV Jabalpur 400kV Jabalpur-Itarsi#2 PGCIL



(Y) 14.05.09 15:03 19.07.09 20:17 18 Towers collapsed.


(Y) 14.05.09 15:03 30.05.09 19:58 18 Towers collapsed.


MSETCL (Y) 14.05.09 19:16 15.05.09 1:30

Transient B-N fault. Line was recharged at 21:57 & 22:27hrs. From Koradi end but tripped onreceipt of DT signal from Akolaend because of O/V protn optd.at Akola.


(Y) 14.05.09 07:06 ??? ??? Line tripped on over voltage


(Y) 14.05.09 07:06 14.05.09 08:00 Line tripped on over voltage


(Y) 14.05.09 19:16 15.05.09 12:12

Line tripped on DT receive at Wardha end. PLCC maloperation




(Y) 15.05.09 16:45 15.05.09 16:56 Persisting B-N fault.

3.62 400kV Bina 400kV Bina-Nagda#2 PGCIL (Y) 15.05.09 17:49 15.05.09 18:06

Persisting R-N fault.

3.63 400 KV Raipur 400 KV Raipur-Bhilai # 2 PGCIL

(Y) 15.05.09 18:23 15.05.09 18:23 Line A/R successfully on R-E

fault.F.L=14Km from Raipur



3.65 400kV V'chal 400kV V'chal-Jabalpur#1 PGCIL

(Y) 17.05.09 3:57 17.05.09 5:05 Maloperation of Reactor Backurelay (RAKZB) at VSTPP end.



3.67 400kV Koradi 400kV Koradi-Bhusawal MSETCL

(Y) 17.05.09 18:04 17.05.09 18:04 Transient Y-N fault. A/R successful at both ends.

3.68 400kV Koradi 400kV Koradi-Parli#2

MSETCL (Y) 17.05.09 18:22 17.05.09 20:21

Transient B-N fault. Trip ckt faulty indication appeared aftertripping at Koradi end. Problemwas located in the Gas PressureSwitch. The line charged through TBC 1.

3.69 400 KV Raigarh 400 KV Raigarh-Rourkela # 2 PGCIL

(Y) 17.05.09 16:07 17.05.09 19:54

Line tripped on earth fault. F/L = 284 km from Raigarh.TEE diff. prot. Optd at Rourkela end

3.70 400kV Padghe 400kV Padghe-Nagothane-1 MSETCL

(Y) 18.05.09 13:47 18.05.09 17:55

B-E, Zone-1. B-ph decapping observed at loc.No.5

3.71 400kV Padghe 400kV Padghe-Bableshwar-1 MSETCL

(Y) 19.05.09 16:12 20.05.09 3;46

YB, Zone-1. Patrolling done no fault found, Transient nature of fault

3.72 400 KV Raipur 400 KV Raipur-B'wati # 2 PGCIL

(Y) 19.05.09 15:30 19.05.09 15:58 Line tripped on B-E Fault at 265.6 Km from Bhadrawati.A/Rsuccessful at Raipur end



3.74 400kV Padghe 400kV Padghe-PGCIL (Boisar) MSETCL

(Y) 21.05.09 8:22 21.05.09 10:40

B-E, Zone-1. Patrolling done, no fault found Transient nature of fault.

3.75 400 KV Boisar 400 KV Boisar-PadghePGCIL

(Y) 21.05.09 09:24 21.05.09 09:41 Line Tripped on B-E fault . Fault in Z2 from Boisar, and nocarr. Received at Boisar




(Y) 22.05.09 17:20 22.05.09 17:20 Transient B-N fault. A/R successful at both ends.



3.79 400 KV Chorania

400 KV Chorania-Amreli GETCO

(Y) 24.05.09 0:30 25.05.09 0:57 Due to problem in R - ph CVT WS Make replaced.


(Y) 24.05.09 12:30 02.06.09 22:10 3 Nos Tower collapsed.


(Y) 24.05.09 12:30 02.06.09 22:36 3 Nos Tower collapsed.


Persisting B-N fault.

3.83 400 KV Raipur 400 KV Raipur - Sipat # 2 PGCIL

(Y) 24.05.09 16:51 24.05.09 17:25

Line A/R successfully at Raipurend but tripped at Sipat end on Y-G fault at 136.3 kM from Raipur.





3.86 400 KV Wardha 400 KV Wardha-Akola # 2 PGCIL

(Y) 25.05.09 15:56 25.05.09 17:38 Line tripped on DT received at Wardha end. PLCC maloperation.

3.87 400 KV B'wati 400 KV B'wati-C'pur # 4 PGCIL

(Y) 26.05.09 17:27 26.05.09 17:56

Line tripped at Chandrapur endon B-E fault at 2.8 KM from B'wati end.Auto reclosure successfull at B'wati end.



3.89 400kV Raipur 400kV Raipur-B'wati # 2 PGCIL

(Y) 30.05.09 17:30 30.05.09 17:30 Line A/R successfully on Y-Efault.F.L=26.53 Km from Bhadrawati

3.90 400kV Raipur 400kV Raipur-B'wati # 3 PGCIL

(Y) 30.05.09 17:30 30.05.09 17:30 Line A/R successfully on R-E fault.F.L=29.9 Km from Bhadrawati


Transient R-N fault.

3.92 400 kV B'wati 400 kV B'wati - C'pur # 4 PGCIL

(Y) 31.05.09 16:28 31.05.09 18:02 Line tripped on persistant B - Efault at 2.9 kM from Bhadrawatafter attending A/R at both ends

3.93 400 kV B'wati 400 kV B'wati - C'pur # 3 PGCIL

(Y) 31.05.09 16:28 31.05.09 18:12 Line tripped on persistant B - Efault at 2.9 kM from Bhadrawatafter attending A/R at both ends


(Y) 01.06.09 6:42 01.06.09 7:00 Phase to Phase (Y-B) fault.

3.95 400kV Bhilai 400kV Bhilai-Korba (W) CSPTCL

(Y) 01.06.09 18:31 01.06.09 18:56 Tripped from both end on BN fault. A/R L/O.

3.96 400 KV Raipur 400 KV Raipur - Sipat # 3

PGCIL (Y) 03.06.09 03:45 03.06.09 11:54

Line successfully auto reclosedat both ends on R - E fault at 108 km from Raipur end. Line again tripped on receipt of DT signal due to overvoltage protection operated at Sipat end

3.97 400kvC'pur 400kvC'pur-Koradi MSETCL (Y) 04.06.09 18:28 04.06.09 18:28

Transient B-N fault. A/R successful at both ends.



3.99 400 KV Raipur 400 KV Raipur - Sipat # 1

PGCIL (Y) 04.06.09 00:24 04.06.09 01:53

Line tripped on Y - E fault at 70.7 kM from Raipur. A/R operated successfully, but line tripped due to persistent fault inline.

3.100 400 KV Raipur 400 KV Raipur - Bhilai # 1

PGCIL (Y) 04.06.09 08:48 04.06.09 10:21

Line tripped with external flashover occurred on B - Phase CT of Main Bay at Bhilai end due tstormy wind with heavy dust passed over the CT.

3.101 400 KV Raipur 400 KV Raipur - Bhilai # 2 PGCIL

(Y) 04.06.09 08:48 04.06.09 09:28 Line tripped only at Raipur endin zone-2 for CT external flashover at Bhilai

3.102 400 KV Bhilai 400 KV Bhilai - Korba # 1 PGCIL

(Y) 04.06.09 08:48 04.06.09 09:39 Line tripped only at Korba in zone -2 for CT external flashover at Bhilai

3.103 400 KV Bhilai 400 KV Bhilai - Korba # 2 PGCIL

(Y) 04.06.09 08:48 04.06.09 09:29 Line tripped only at Korba end in zone-2 for CT external flashover at Bhilai


(Y) 04.06.09 15:18 04.06.09 15:18 Line successfully auto recloseat both ends on B - E fault at 7.89 km from Raipur





3.107 400 KV Raipur 400 KV Raipur-B'wati # 1 PGCIL

(Y) 05.06.09 02:46 05.06.09 02:46 Line successfully auto recloseat both ends on Y - E fault at 190 km from Raipur


(Y) 05.06.09 14:48 05.06.09 14:48 Line successfully Auto Reclosed at both ends on Y - Efault at 82 kM from Raipur.


(Y) 05.06.09 14:50 05.06.09 14:50 Line successfully Auto Reclosed at both ends on Y - Efault at 82 kM from Raipur



3.111 400 KV Korba 400 KV Korba - Korba (W) PGCIL

(Y) 05.06.09 18:52 05.06.09 19:26

Line tripped because of relay maloperation at Korba end, dueto tower collapase of 400KV Bhilai-Korba(W) # 1.

3.112 400kV Padghe 400kV Padghe-Lonikand MSETCL

(Y) 06.06.09 1:54 06.06.09 16:11 Y-E, Zone-1 Y-ph decapping observed at locNo.19

3.113 400kV Nagothane

400kV Nagothane-Padghe-2 MSETCL

(Y) 06.06.09 5:33 06.06.09 6:16 O/V stage-1 Over Voltage = 416KV at Nagothane end




(Y) 06.06.09 08:31 06.06.09 08:31 Auto Reclosure on R-E fault aFault location 133 KM from Bhilai


(Y) 06.06.09 15:33 06.06.09 15:52 Line tripped on Bph to Earth fault at Fault location 199Km from Bhilai.

3.117 400 KV Korba 400 KV Korba-Bhilai # 1

PGCIL (Y) 06.06.09 15:33 17.06.09 21:41

Line tripped due to 3 Towers collapsed at location 88, 89, 90 because of heavy rain and windFault location 159.5 KM from Bhilai.

3.118 400 KV Raigarh 400 KV Raigarh-Rourkela #2 PGCIL

(Y) 06.06.09 17:25 06.06.09 17:25 Auto reclose successful on Y-Efault at Fault location 66 KM from Raigarh.

3.119 765 KV Seoni 765 KV Seoni-Wardha # 1 PGCIL

(Y) 06.06.09 19:03 06.06.09 19:29 Line tripped on over voltage stage-I protection.

3.120 400 KV Wardha 400 KV Wardha-Akola #2 PGCIL

(Y) 06.06.09 19:03 06.06.09 19:44 Line tripped on over voltage stage-I protection

3.121 400 KV Asoj 400 KV Asoj-Chorania-1 GETCO

(Y) 07.06.09 9:05 07.06.09 9:33 Over voltage stage -1 at asoj end.

3.122 400 KV Bhilai 400 KV Bhilai-Koradi line

PGCIL (Y) 08.06.09 11:35 08.06.09 11:49

Line tripped on Y - E fault at 40.2 Km from Bhilai. and , Line successfully A/R at Bhilaiend but tripped at Koradi end Main 2 protn found optd on DEF causing L/O. Opn. Of DEFneeds to be discussed.

3.123 400 KV B'wati 400 KV B'wati-C'pur # 4 PGCIL

(Y) 08.06.09 17:14 08.06.09 17:14 Line successfully Autorecloseat both the ends on B-E fault a7.37 KM from Bhadrawati end.

3.124 400 KV Raigarh 400 KV Raigarh - Rorkela # 1

PGCIL (Y) 10.06.09 20:30 10.06.09 21:31

Line tripped on B - E fault at 243 Km from Raigarh, successfully auto reclosed at Raigarh end,auto reclose unsuccessfull at Rourkela end.


(Y) 12.06.09 15:09 12.06.09 16:24 Prsisting Y-N fault.


(Y) 12.06.09 19:02 12.06.09 19:15 Line tripped on Over Voltage



3.128 400 KV Ranchi 400 KV Ranchi - Sipat # 1 PGCIL

(Y) 13.06.09 18:32 ??? ??? Line tripped at Sipat end for Reactor fault at Rorkela .



3.130 400kV Vapi 400kV Vapi-Sugen PGCIL (Y) 15.06.09 4:28 15.06.09 14:20

Prsisting B-N fault.

3.131 400kV C'pur 3x105MVA,400/220kV ICT 2

MSETCL (Y) 16.06.09 9:49 16.06.09 10:02

Spurious tripping due to unknown cause. Investigation done in detail by taking outage,nothing abnormal found. ICT kept under observation.



3.133 400/220kV Raipur

400/220KV ICT#2 PGCIL (Y) 17.06.09 23:08 18.06.09 00:14 ICT tripped on over fluxing.



3.135 400kV Sarni 400kV Sarni-Indira Sagar MPPGCL 18.06.09 17:07 18.06.09 17:40

Line tripped from both end ontransient Y-N fault.

3.136 400 KV Kasor 400 KV Kasor -Gpec GETCO

(Y) 19.06.09 9:18 19.06.09 9:43 After patroling no cause found.

3.137 400kV Khandwa

400kV Khandwa-Dhule#1 PGCIL

(Y) 19.06.09 16:26 16.07.09 21:39 5 nos. Towers collapsed.

3.138 400kV Khandwa

400kV Khandwa-Dhule#2 PGCIL

(Y) 19.06.09 16:26 ??? ??? 5 nos. Towers collapsed.



3.140 400kV Itarsi 400kV Itarsi-Satpura PGCIL (Y) 21.06.09 16:35 21.06.09 18:56


3.141 400kV Sarni 400kV Sarni-Itarsi

MPPGCL 21.06.09 16:40 21.06.09 18:56

Line tripped from both ends on Y-N fault. A/R L/O. Line test charged but tripped on pole discripancy.


Transient Y-N fault.


(Y) 22.06.09 19:20 22.06.09 19:58 Line tripped at Koradi end on receipt of DT on operation of O/V stage-I at Akola.

3.144 400kV Khandwa

400kV Khandwa-Seoni#1 PGCIL



A/R successful on transient YN fault.

3.146 400 KV Vapi 400 KV Vapi-Boisar

PGCIL (Y) 22.06.09 17:33 23.06.09 11:32

Line tripped on B-E fault due toinsulator string failure.F/L= 90.KM from Boisar end.Reclosingattempted but tripped on persistant fault.



3.148 400 KV Wardha 400 KV Wardha-Akola #1 PGCIL



Transient R-N fault. A/R successful at both ends.


Transient B-N fault. A/R successful at both ends.




(Y) 23.06.09 19:05 23.06.09 19:15 Transient Y-N fault.

3.153 400kV Raipur 400/220KV ICT # 1 PGCIL (Y) 24.06.09 05:16 24.06.09 20:01 ICT tripped on over fluxing.







Persisting R-N fault.

3.158 400 KV Korba 400 KV Korba - Korba (W) PGCIL

(Y) 25.06.09 02:35 26.06.09 21:46 Line tripped due to failure of 'Rphase CT at Korba (W)CSEB end.


3.160 400 KV Bhilai 400 KV Bhilai - Seoni PGCIL

(Y) 25.06.09 15:38 25.06.09 18:35 Line tripped due to operation ofReactor Protection at Bhilai end

3.161 400 KV Bhilai 400 KV Bhilai - B'watiPGCIL

(Y) 25.06.09 18:32 25.06.09 18:32

Line successfully Auto reclosed at both ends on R - Efault at 142.2 kM from Bhadrawati end.

3.162 765KV Seoni 765KV Seoni - Wardha # 1 PGCIL




3.164 765KV Seoni 765KV Seoni - Wardha # 1 PGCIL



(Y) 26.06.09 19:05 ???? ???? Line tripped on over voltage


(Y) 28.06.09 17:00 28.06.09 17:00 A/R successful on transient BN fault.


MSETCL (Y) 29.06.09 3:14 29.06.09 6:00

Line tripped at Koradi end on receipt of DT on operation of O/V stage-I at Akola. The O/V occurred after tripping of AkolaBhusawal line due to fault in wave trap.


(Y) 29.06.09 03:13 ???? ???? Line tripped on over voltage


(Y) 30.06.09 19:20 30.06.09 20:10

Line tripped on R - Earth Fault at 5.135 kM from Bhilai. A/R unsuccessful due to maloperation of REL 531 relay

Annexure –4 Present status on recommendations pertaining to Protection of Inquiry Committee on grid disturbances of 25.02.2007 and 28.02.2007 Sr no

Recommendations

I

Decisions and Suggestions of PC for

implementing the recommendations

II

Status

III

i) Both Main- I and Main –II protection on 400 kV Padghe- Nagothane Ckt-I is provided by ABB make REL 521 relays with same characteristic and settings thereby defeating the purpose of providing selectivity and discrimination of the fault. In line with Section 2 of CBIP Publication 274 of November 1999, Main-I and Main-II protection should be of different types and not necessarily of different make.

It was decided in the 99th and 100th PCM that as a first step all constituents shall identify and intimate such feeders where both Main-I and Main-II protections having similar characteristics are provided. Also wherever possible constituents shall swap the relays and achieve the objective of providing Main-I and Main-II protections having different characteristics of operation. Committee will review the progress made by constituents with regards to these identified feeders. It was decided in the 104th PCM that constituents would furnish details of Main-I & Main-II relays for all 400kV lines to WRPC which will then be discussed in next PCM.

MSETCL intimated that on 400 kV Padghe – Nagothane ckt-I, Main-I and Main-II protections have been provided with different characteristic and settings at Nagothane and Padghe end. REL 521 Main-I relays provided at Padghe end replaced with Siemens make relay on 13th Sept 08. In pursuant of the decision of the PC, MSETCL had submitted the information regarding the feeders having similar Main-I and Main-II characteristics, in respect of Nagpur, Nasik and Vashi Circles. PGCIL have implemented the recommendation except on 400kV Indore-Asoj line which will be done within 2 months. GETCO have implemented the recommendation except two fdrs. Viz. 400kV Choradia-Hadalia & Choradia-Jetpur.

ii) The Committee observed that distance relay REL 521 does not have the feature of recording switching off of auxiliary DC supply to the

a) As agreed in 98th PCM MSETCL took up the matter of incorporating

A) ABB have intimated that whenever DC supply is switched off,

relay as an internal event among recording of other related relay supervision parameters. For the grid disturbance of 25.2.2007, the time of switching off of DC auxiliary supply was very crucial information, which was not available. The possibility of incorporating the time of switching off of DC auxiliary supply as an internal event recording may be taken up with the manufacturer.

the time of DC supply off to relay as an internal event with M/S ABB.

b) For future procurement this requirement may be added in the specification of relays itself.

c) Committee in its 100th PCM suggested that as an alternative watch dog contacts available on fascia can wired up to log as an event on SER provided in sub -stations.

d) In 101st PCM the Committee suggested that in case SER is not provided in the S/s it is suggested that, wherever possible DC supply OFF contacts of Main-I & Main-II relays can be wired to Main-II & Main-I relays respectively, thus DC supply OFF event of both the protection schemes is stored in either of the relay.

relay can not function and hence event can not be stored “DC off “ as an internal event in a memory, so suggestion made by enquiry committee can not be implemented. Committee felt that reply of M/s ABB was satisfactory and recommended that suggestions made in 100th and 101st PCM’s to overcome the problem may be implemented.

In 104th PCM MSETCL informed that at Koradi, Padghe, New Koyna & Aurangabad S/S this feature has been implemented through SMS. At Dhule, Lonikand, Parli & Chandrapur S/S’s it will be implemented by Dec 09. In 104th PCM PGCIL informed that the feature have been incorporated in the event logger (stand alone) with GPS stamping. GSECL informed that this feature is incorporated in SER’s In 104th PCM GETCO informed that this feature has been incorporated in SER’s. In 104th PCM MPPTCL informed that the feature will be incorporated in event loggers and it is

under procurement stage. iii) The triggering of disturbance

recorders at Padghe substation gets initiated only with the relay operation. Therefore, disturbance recording would not take place if the relay has not operated. The Committee recommends that the DRs should also have analog triggering signal from voltage/current/frequency threshold to ensure generation of DR data.

Committee discussed and recommended the following threshold values for current and voltages to trigger DRs during 100th PCM

a) High Voltages:-150 % 0f nominal voltage.

b) Low Voltages:- 70% of nominal voltage without any intentional time delay.

c) Over Current:-150% of rated secondary current with time delay of 1 sec can be given for triggering DRs.

A) In 101st PCM MSETCL Nasik and Vashi informed that they have implemented the decisions in most of S/Ss, and constituents were requested to follow the suite.

B) Till the SMS is implemented in MSETCL, MSETCL Nagpur Circle may adopt a time delay of 100msec for high and low voltage triggering of DRs.

C) In 105th PCM GETCO informed that they have implemented the decisions except 400kV Asoj-Indore 1 & 2 lines.

D) In 105th PCM PGCIL informed that they have implemented the decisions in all the S/S.

E) In 104th PCM MPPTCL has informed that they have implemented. The settings will be confirmed.

iv) The Committee expresses its concern that 400kV Padghe substation does not have compatible device to download the disturbance data recorded from the memory of the numerical distance relays installed on

Protection Committee stressed the importance of compatible data download facility and requested constituents to arrange for same expediously.

MSETCL informed that data down loading facility from numerical relays has been included in their Substation Monitoring Schemes (SMS) and would be made available. Vashi,

400kV lines. The Committee recommends that every sub-station having numerical relays be provided with compatible data downloading device to facilitate analysis of the vital information.

Nasik and Nagpur Circles of MSETCL had provided laptops at all the S/s for downloading the data. GETCO has confirmed that data down loading facility has been made available at all the S/s. PowerGrid has confirmed that data downloading facility is available at all the S/s. All other constituents were requested to follow suite and intimate the progress. CSEB informed that this recommendation is in process of implementation and will be complied. MPPTCL informed that this facility has been included in ERPC (Enterprising Resource Planning Scheme), which is under tendering process. In 104th PCM MPPTCL informed that manual downloading facility is made available at S/S’s.

v) The simulation studies indicate that the distance protection scheme provided on some lines are under-reaching due to in-feed effect. Protection Committee of WRPC may look into this aspect and review the settings of 400 kV lines considering in-feed.

In 98th PCM it was agreed that Zone –III settings considering in-feed effect is to be arrived after due study and on case to case basis. It was suggested that each state should initiate studies starting with any one station in their system results of the study may be put up to Committee for further discussions. During 104th PCM Constituents were requested to carryout study for one of the 400kV S/S in their

MSETCL informed that protection review group has been formed and the group will take up this issue as a part of their study activity.

system and put up to committee for further review. MSETCL was requested to pursue with the protection review group to take up the issue for Padghe S/S.

vi) Since the 400 kV Chandrapur-Parli T/c is a very important corridor for power flow, the relays on this line should be replaced at the earliest by latest type of numerical relays. Meanwhile the feature of lenticular characteristics available in micromho relay may be used as an interim measure instead of circular characteristics feature being presently used.

MSETCL has confirmed that all the three feeders of 400 kV Chandrapur – Parli are fitted with numerical Areva make Micom- P 44 2 relays at both ends as main-I and main-II protection and the recommendation has been complied.

vii) With the tripping of ± 500 kV Chandrapur-Padghe HVDC link, large quantum of power gets suddenly diverted to other alternative A.C. networks and usually results in tripping of a number of lines on power swings. The Committee recommends that with the tripping of the both poles of HVDC link, generation level at Chandrapur thermal power station of MSPGCL may be brought down automatically to prevent spread of the disturbance. WRPC may work out a suitable scheme in consultation with MSETCL

MAHAGENCO & MAHATRANSCO were requested to expedite action to formulate the scheme.

105th PCM MAHAGENCO representative informed that the matter has been taken up with MAHATRANSCO. MAHATRANSCO representative told that a study group has been formed at HO level to study the matter and come up with draft scheme, which would then be taken up for discussions in the PCM.

viii) In the grid disturbance of 25th February, 2007, the ER-NR inter tie got tripped resulting in disconnection of NR grid from ER grid. Subsequently, some more inter-regional links between

Matter regarding formulation of special protection scheme to avoid disturbance due to occurrence in other region has been referred to CEA New Delhi for

ER/NR and NR/WR have been added which may help in reducing the impact of a disturbance in a Region on other Regions operating in parallel. However, the committee is of the view that special protection scheme be worked out on priority and implemented between the various Regions operating in interconnected mode so as to minimize the impact of a disturbance in a region on other regions.

further action. WRLDC informed that they are in process of carrying out studies in order to devise special protection schemes in the event of tripping of regional links. As NR, WR, ER and NER are interconnected with many 400kV and 220kV links, a composite study is required to arrive at SPS in connection with regional links. The results of the studies carried out by WRLDC will be put up to the Protection Committee for further action.

Documents

Baart sarkar Government of India kond`Iya ivaVut p ... · with 220 KV Dahej, 220/66 KV 50 MVA T/F and 220 KV Bus Coupler at 220kV Wagra S/S. All the above feeders were connected to