MN.PDF

फोन - Ph. : 26513265 ई मेल e- mail: [email protected]

फे स Fax : 26865206 वेबसाईट Website : www.nrpc.gov.in भारत सरकार

उ र े ीय िव ुत सिमित 18-ए, शहीद जीत िसंह माग, कटवा रया सराय नई िद ली - 110016

Government of India Northern Regional Power Committee

18-A, Shaheed Jeet Singh Marg, Katwaria Sarai, New Delhi-110016

No. NRPC/SE (O)/13-PSC/11/ Dated: 25.02.2011

FAX MESSAGE From : Superintending Engineer (O), NRPC. To : Members of Protection Sub-Committee 1. Director (P&C)/BBMB, Chandigarh, Fax-0172-2652054 2. SE (Elect.Op), UT of Chandigarh, Chandigarh - 160 009, Fax-0172-2740505 3. General Manager (O&M) DTL, New Delhi, Fax-23221059 4. GM (SLDC), Delhi Transco Limited, New Delhi, Fax-23221059 5. GM (T), Common Services IPGCL, New Delhi,, Fax-23370247 6. Chief Engineer (TS), HVPNL, Panchkula, Fax-0172-2591244 7. SE (M&P), HVPNL, Dhulkote , Haryana, Fax-0172-2540014 8. SE (PPM), Haryana Power Generation Co. Ltd., Panchkula , Fax-0172-2586836 9. Director (Technical-II), UHBVN, Panchkula, Fax-0172-3019112 10. Chief Engineer (Transmission), HPSEB, Hamirpur, Fax-01972-223435 11. Chief Engineer (Comml. & Survey Wing) PDD, Jammu, Fax-0191-2474233 12. Chief Engineer (P&M),PSEB, Ludhiana , Fax-0161-2741280, 2451491 13. SE (Protection), RRVPNL,Jaipur, Fax-0141-2296755 14. SE (Protection), RRVUNL,Suratgarh, (Rajasthan), Fax-0141-2740920 15. Managing Director, Jodhpur Vidyut Vitaran Nigam Ltd., Jodhpur, Fax-0291-2741870 16. Superintending Engineer (T&C), UPPCL, Meerut (U.P.), Fax-0121-2666062 17. Chief Engineer, (L-2), UPRVUNL Lucknow, Fax-0522-2287822, 2287880 18. MD, Dakshinanchal Vidyut Vitran Nigam Ltd.,Agra, Fax-0562-2605465 19. DGM (T&C), PTCUL, Dehradun, Fax-0135-2760331 20. DGM (In-charge), Yamuna Valley, UJVNL,Dehradun, Fax-0135-2763507 21. Chief Engineer (O&M), NHPC ,Faridabad, Fax-0129-2272413 22. Chief Engineer (O&M), NPCIL, Mumbai, Fax-022-25563350 23. GM (O&M) NR – I, PGCIL, New Delhi , Fax-011-26601079 24. GM (O&M), NR-II, PGCIL, Jammu, Fax-01951-237186 25. Chief Manager (TS), N.R.L.D.C, New Delhi, Fax- 011-26852747 26. GM (OS) NTPC Ltd.,Noida, Fax-0120-2410082, 2410068 27. DGM (Maintenance), SJVNL, New Shimla, Fax- 0177-2673283 28. AGM (El. Design), Design & Engineering (Electrical), Rishikesh, Fax-0135-2438682 29. Director (GM division), CEA,New Delhi, Fax-011-26109750 ….....................................................................................................................................................Sub:-Minutes of the 13

th Protection sub Committee Meeting held on 28th January, 2011

The 13th Protection sub Committee meeting was held on 28th January 201 at NRPC, New Delhi.

The minutes of this meeting can be downloaded from NRPC website at http://www.nrpc.gov.in. (Ajay Talegaonkar) Superintending Engineer (O)

Summary Record of Discussion Of

13th PSC Meeting

The 13th meeting of Protection Sub-committee was held on 28th January 201 at NRPC, New

Delhi. The list of participants is enclosed at Annexure-I.

A.1 CONFIRMATION OF MINUTES OF 12th MEETING OF PROTECTIONSUBCOMMITTEE.

The Sub Committee confirmed the minutes of the 12th meeting.

B.1.CO-ORDINATION OF RELAY SETTINGS FOR PROTECTION OF TRANSMISSION LINES OF DIFFERENT UTILITIES / ORGANISATIONS

B.1.1 SE (O) stated that uniform philosophy for protection of lines to avoid indiscriminate

tripping under fault condition need to be implemented by all the Constituents. To monitor the

implementation, it was decided in the 11th PSC meeting held on 23rd April 201 that a system of

periodic self certification along with deviation, if any, with reason with respect to setting

recommended by NRPC by all the constituents / utilities should be established for the lines

above 400 kV and generation station 210 MW and above. Uniform Protection philosophy

accepted by PSC along with self-certification format is given in Annexure-I. He stated that only

HVPNL and SJVNL has submitted the certificate.

Representative of DTL, RVPNL and NHPC stated that they would submit the certificate within

15 days.

SE(O) further stated that in order to verify and monitor the coordination of relay settings for

protection of transmission lines in the Northern Region, all utilities are requested to submit

details of relays provided in their system and protection setting adopted by them(Annexure-II). Annexure-II is available at NRPC website (www.nrpc.gov.in). He informed that information from

BBMB, PGCIL, NJHPS, THDC, NHPC, DTL, RVPNL, have already been received. He

requested other utilities to submit the details through e-mail ([email protected]).

B.1.2 df/dt relay setting

SE (O) stated that it was decided in 12th PSC that the measurement time of df/dt relay shall be 08 to 10 cycles. The members informed that the spurious tripping due to df/dt relay had not occurred after change of setting. All the state constituents agreed to furnish data to substantiate the same.

B.1.3 Provision of directional earth fault (DEF) on all the 400 kV lines SE (O) stated that as per the protection philosophy agreed for implementation in the Northern

Region, backup protection on all the 400 kV and 220 kV lines with two main protections should

also have backup earth fault protection. But it has been observed during the grid incident on 2nd

January 2010 provision is DEF is not available for certain utilities.

RVPNL and DTL confirmed that they have already implemented the scheme.

MS, NRPC requested the utilities to submit their action plan for the implementation of the same.

B.2 Protection Audit for up gradation of Protection System

SE (O) stated that CPRI has submitted the 2nd interim report to DTL on protection audit and requested DTL to give a brief presentation to PSC. Representative of DTL told about the process of audit and recommendations. He stated that they are implementing the recommendations in a phased manner. He further stated that some work is still pending with CPRI and it would be completed within a month. Representative of HPGCL stated that Bus Bar protection should also be a part of audit and it can be tested for one or two sub-station.

SE (O) stated that it was decided in the 17th NRPC Meeting held on 17th July, 2010 that the CPRI may be entrusted with the task of protection audit. Accordingly a proposal of from CPRI has been received which has been forwarded to CERC with copy to Secretary, PSDF. He further stated that in 18th NRPC meeting held on 27th November, 2010, it was decided that expert group on protection formed by Protection sub- committee would consolidate the proposal and submit it for funding from PSDF. However, as per draft procedure for disbursement from PSDF, individual utility would have to submit their proposal to PSDF Managing Committee in the prescribed format. NRPC Secretariat/ Expert group might facilitate the same.

MS, NRPC requested utilities to submit their proposal directly to PSDF managing Committee.

B.3Status of Availability/Commissioning of Bus Bar Protection at each 400 kV & 220 kV Substation

SE (O) stated that as decided in 4th, 5th, 6th, 7th, 8th and 9th PSC that all the constituents are to

implement Bus Bar protection at 400 kV and 220 kV substations to improve the reliability of the

system. The detailed status of Bus bar protection schemes provided at 400kV and 220kV

substations have been received from all constituents except J&K, RRVUNL and UPPTCL.

SE (O) enquired from the representative of BBMB about the stated non requirement of Bus Bar

protection for Barnala, Sangrur, Kurukshetra and Delhi. Representative of BBMB stated

that they would revert back.

Representative of DTL stated that scheme would be implemented at Kanjhawala sub-

station within 2 months and at Gopalpur sub-station it will take more time due to cable

problem. SE (O) stated that Bus Bar protection is mandatory as per Grid Connectivity Standard of CEA

and if the protection is not in service it is violation of regulations.

MS, NRPC stressed the need to expedite the implementation of Bus Bar Protection by utilities.

SE(O), NRPC requested utilities to submit the information in prescribed format, which is given

below:

(Signature of SLDC Head)

The summarised status of bus bar protection in the State utilities as updated by the members is given as Annexure-III

B.4 Single Pole Auto-Reclosing on 220 kV and above line

Name of State

Bus bar protection

S.No Name of generating station/ Sub-Station

Bus bar protection provided and in service

Bus bar protection provided but not in service (with reason)

Installation in progress/ under construction(with target date of completion)

Bus bar protection not provided

SE (O) stated that it was decided in 4th, 5th, 6th, 7th, 8th and 9th PSC that all the constituents are

to implement Single Pole Auto reclosure schemes on all lines of 220 kV and above. During the

13th NRPC meeting also it was decided that all lines of the region will have Single Pole Auto

reclosing schemes and the same is to be implemented by March 2010 to improve the stability

and reliability of the system. But the response of utilities is not satisfactory about the

implementation.

SE (O) requested the representative of HPSEB Ltd, PDD, J&K, PTCUL and RRVUNL to submit

the information of Single Pole Auto reclosure schemes on all lines of 220 kV and above.

These utilities are requested to provide the information in following format through email

([email protected]): Name of State/Organization

Single Phase Auto Re closure Scheme

Name of Transmission Line

Name of generating station/ sub-station from where line is emanating

Auto Re closure protection provided and in service

Auto Re closure protection provided but not in service (with reason)

Installation in progress/ under construction(with target date of completion)

Auto Re closure protection not provided / not required(with reasons thereof)

From To

400 kV

220 kV

(Signature of SLDC Head)

SE (O), NRPC stated that in the 17th TCC/18th NRPC meeting held on 26th /27th November 2010, representative of POWERGRID had stated that they are facing problem as scheme has not been installed at other end of the line emanating from POWERGRID Stations and lines terminating in Constituents’ Stations (List enclosed at Annexure-IV). Representative of RVPNL had submitted the reply along with a list(enclosed at Annexure-IVA). There are certain discrepancies in the information submitted by RVPNL and POWERGRID. SE (O) asked both the utilities to sort out the discrepancies and inform the NRPC secretariat

Utilities were requested to submit the action plan to PSC for implementing Single Phase Auto Reclosure scheme.

B.5 PLCC problem at NAPS SE(O) stated that non-availability of PLCC links between Narora and UPPTCL system affects

direct communication with remote end sub-stations and carrier aided line protection. PLCC links

(voice and carrier inter trip features) between NAPS & UPPTCL sub-stations are defective and

needs to be normalized soon.

MS, NRPC expresses concern about the non-functionality of PLCC links and requested the

utilities to form a committee to sort out the issue. It was decided that Shri Sandeep Servate,

ACE (Trans.), NPCIL, Mumbai and Shri T.R. Gupta, S.E.(ESDC-II), UPPTCL, Lucknow will

discuss the issue separately so that the problem can be resolved.

B.6 Provision of time synchronisation through GPS in all the generating stations / sub-stations of regional importance. SE (O) stated that it was decided that in order to carry out the post analysis of an incidednt, it is

extremely important that all the recording equipment at generating stations / sub-stations, which

are important from regional consideration, must be time-synchronized using GPS.

Apart from time synchronization, the triggering of DRs or ELs or Numerical Relays for different

analog and digital inputs must be tested periodically so as to facilitate proper analysis at the

time of any major tripping.

SE (O) further stated that there is need to test time-synchronization of GPS periodically. Format

for testing is to be filled and certified by constituents and submitted to NRPC/NRLDC. The same

is enclosed in Annexure-V.

C . N E W I T E M S F O R D I S C U S S I O N

C.1 Over-Voltage Stage -I relay setting.

SEO) requested representative of NRLDC to brief the sub committee about the issue.

Representative of NRLDC stated that CBIP manual on Protection, Publication No. 274

Revised recommends

1. The low set stage of O/V protection may be set at 110 % with a typical time

delay of 5 seconds.

2. A time grading of 1 second may be provided between the relays of different

lines at a station. Longest time delay should be checked with expected

operating time of overfluxing relay of the transformer to ensure disconnection

of line before tripping of transformer.

3. Have a high Drop-off to pickup ratio.

Representative of NRLDC stated that both the lines of 400 kV Kishenpur-Baghlihar D/C had tripped simultaneously on over voltage during the blackout of Kashmir valley on 06th and 18th Dec 2010. From the Disturbance recorder output it was noted that the tripping was due to non-provision of grading in 400kV Kishenpur-Baghlihar D/C line at Baglihar end. Member from PDD J & K assured to check the over voltage setting at Baghlihar end and introduce either time or voltage grading in the over voltage protection setting of 400kV Kishenpur-Baglihar D/C lines.

PSC recommended that overvoltage protection on all parallel 400 & 220 kV lines transmission should have either time or voltage grading. The members also agreed to keep a ‘high’ setting of drop off to pick up ratio so that the relay is reset as soon as the voltage goes below the threshold value. It was agreed that all the members would implement the setting in the field and confirm the same to NRLDC/NRPC in the next meeting.

C.2 Over-voltage setting of 400kV Uri-Wagoora line at NHPC Uri end

SE (O) stated that POWERGRID has intimated that there were many trippings of 400 kV

Uri-Wagoora line at NHPC Uri end. POWERGRID had intimated that the trippings were

due to different over voltage settings at both ends of the line.

Representative of NHPC confirmed that the over voltage setting of 400 kV Uri-Wagoora D/C lines at Uri end have been reviewed and made consistent with the setting at 400 kV Wagoora end.

C.3Tripping of 400KV Chamera I - Jalandhar & Chamera I - Chamera II line

Representative of NRLDC said that despite having voltage grading, 400kV Chamera-Jallundhar and 400kV Chamera-1- Chamera-2 often trip simultaneously on over voltage during night off peak hours.

PSC recommended that both voltage as well as time grading could be tried for over voltage setting in 400 kV Chamer-1-Chamera-2 lines. POWERGRID and NHPC agreed to intimate NRPC about the final setting adopted and also apprise the members in the next PSC meeting.

C.4.Best Practices for interrupting charging current when breaker controlling the transmission line is under lockout. SE(O) requested representative of NRLDC to brief the sub committee about the issue.

Representative of NRLDC stated that several incidents of multiple lines outages while

de-energising the line through isolator have been witnessed in the northern region.

Such requirement arises usually when the circuit breaker controlling the line is under lockout. PSC members agreed that when breaker controlling the transmission line is under lock out, it is not advisable to interrupt the changing current through an isolator. PSC recommended the following practice to be adopted in such cases.

1. De-energise the bus connecting the line with lockout CB and then open

the isolator.

2. If due to some reason it is not possible to open the isolator in above

mentioned way, then open the isolator so that no charging current is

interrupted through the isolator and the charging current is diverted to

other parallel path. Such switching sequence could be possible in case of

breaker and half scheme or Double breaker Scheme, which is as follows:

• Open the line from remote end first with direct trip (DT) disabled. With this

now line remains charged from the end where CB has problem.

• In case of breaker and half scheme open the isolator so that charging

current is diverted to the parallel path and after that open the CB of

parallel path.

• In case of double breaker scheme open the isolator of the lockout breaker

diverting the charging current to other CB and then open the CB.

• In case of double main and transfer scheme open the isolator of lockout

breaker so that divert the charging current through transfer bus coupler

and then open the line through TBC circuit breaker.

PSC also recommended that while vacating a bus in such cases, the operators need to check the switching arrangement for individual feeders so as to avoid unintended loss of any feeder.

The Members agreed to implement the protocol as recommended in PSC meeting.

C.5.Distance protection Zone-1 setting in case of short transmission lines. Representative of NRLDC stated that in case of short lines, distance relays usually over-

reach resulting into unwanted tripping of lines. Many a times such tripping may result

into a major disturbance. Problem of over-reach may be overcome by reducing the zone-

1 reach.

PSC was of the view that such setting cannot be reviewed on the basis of one or two

cases. If such over –reaching incidents are too frequent then setting can be reviewed.

C.5 TRIPPINGS IN THE REGION

Some of the important incidents need to be discussed are as under:-

C.5.1.Tripping of Rihand –Dadri Bipole at 1427 hrs of 12th Jan 2011.

NRLDC informed that tripping of HVDC Rihand-Dadri Pole-II followed by tripping of Pole-I at 1427 hours on 12th January 2011 had resulted in operation of the System Protection Scheme intended to take care of the contingency. Members noted that the SPS operation is designed to send signal to back down of generation at Rihand/Singrauli STPS and trip load in Western part of the Northern Grid. NRLDC stated that the sequence of event has been received only from 400 kV Rihand end.

Representative of NTPC agreed to furnish details of automatic generation backdown at Rihand & Singrauli STPS during operation of SPS. POWERGRID (NR1) also agreed to submit the event logger details at Dadri end. Members from State constituents agreed to provide details of automatic load shedding after operation of SPS.

It was agreed that the SPS operation needs to be examined closely particularly in respect of following points

• Whether the quantum of generation backing down at Singrauli/Rihand STPS was adequate as per the design?

• Whether the generation backing down at Sigrauli/Rihand STPS was within the designed time or there was a delay?

• Whether the signal for load shedding generated from HVDC Dadri end was sent to the intended locations?

• Whether the signal for load shedding generated from HVDC Dadri end was received at the intended locations?

• Whether the feeders destined to be tripped as a result of SPS action were in service? If yes how much load were they carrying and did the feeders trip upon receipt of the load shed signal?

• What was the reason for non-tripping of those feeders where signal was received but still they did not trip.

All the members agree to submit data/analysis report to NRLDC/NRPC Secretariat on the above issues and plug the identified gaps if any in coordination with POWERGRID.

POWERGRID was also requested to examine the reason for tripping of the second pole after tripping of the first pole and apprise the PSC regarding remedial measure taken.

C.5.2 Tripping of Kota TPS, RAP-C and RAP-A units

PSC members expressed concern at the frequent multiple outage at KTPS. Representative of RUPNL agreed to furnish the D.R / E. L., tripping and analysis report for tripping of units at KOTA TPS on 13th January 2011 to NRPC Secretariat & NRLDC.

Representative of NRLDC requested to check the protection coordination of distance relays for 220kV lines from KTPS, 220 Kota (S), RAPP-C, RAPP-A.

Representative of NRLDC also requested RAPS-C to check the reason for poisoning out of RAPS-C nuclear reactor. RAPS-C representative informed that RAPS-C reactor had poisoned out due to tripping of auxiliaries on under-voltage. They confirmed that the under voltage setting for tripping of auxiliaries was earlier set at 70 % instead of the desirable setting of 40 % and the same has been rectified.

C.5.3 Multiple tripping of lines at 400kV Agra (U.P) substation on 8th January 2011 at 19:39 Hrs: While discussing the tripping at 400 kV Agra (UP) on 12thJan 2011, UPPTCL informed that bus- bar protection was out of service at Agra (U.P). In this context members agreed that when ever any protection system such as Bus Bar protection, LBB protection, Auto reclose etc. is taken out of service for any maintenance work, an operational code would be taken from SLDC/RLDC before switching in/out such critical protection at generating station or grid substation.

C.5.4, Multiple tripping at 400kV Azamgarh substation at 06:34 hrs on 7th January 2011 and C.5.5 Multiple tripping of Lines at 400kV Bareilly (U.P) substation at 00: 56 Hrs on 2nd January 2011 SE (O) expressed concern of the delay/non-submission of analysis report/DR-EL prints subsequent to tripping events in the grid. He stated that the constituents must comply with the IEGC regulations that bind all the constituents, utilities to submit information report to NRLDC/NRPC after grid events.

UPPTCL agreed to submit D.R,/E.L records and a detailed analysis report on the incident at Bareilly (U.P), Agra (U.P) and Azamgarh to NRPC Secretariat & NRLDC for tripping at substations in the month of January 2011. UPPTCL also agreed to apprise the PSC on the remedial measure taken in each case.

C.5.6 Mechanical failure of 400 kV CB in Theri HPP unit-4

Representative of THDC stated that the generator of Unit #4 (250 MW) of the Tehri HPP

suffered damage at about 01:30 hours on November 4, 2010 following mechanical

failure of the 400kV circuit breaker during shut down of the unit.

During the shutdown on November 4, the load on the unit ramped down and when the

load was less than about 15 MW, a signal to open the 400kV circuit breaker was issued

by the system. However, one pole of the breaker failed to open. It damaged the Damper

Bus bars & Insulation of Rotor poles due to Reverse Power.

C.5.7 Grid Incident on 17.01.2010 in Delhi System at 6:22 Hrs.

SE(O) requested representative of DTL to brief the sub committee about the incident

Representative of DTL. stated that at the time of incident, Pragati Unit I and S.T.G. were

connected to Mandola side through 220kV Wazirabad-Geeta Colony-Patparganj-220kV

IP-IP Ext.(Pragati) Ckt. and Unit 2 was connected to Maharani Bagh side through 220kV

Pragati-Sarita-Vihar, 220kV Sarita-Vihar-Maharani Bagh Ckt and 220kV Maharani Bagh-

Pragati Ckts. The tripping of 220kV Pragati-Sarita Vihar Ckt. and 220kV Pragati-

Maharani Bagh Ckt. caused the Islanding of the Pragati Unit 2 and GT Units from the

Grid and Islanding survived with load of Parkstreet and radial load of GT. However

Pragati Unit-2 and GT STG 1, 2, 3 tripped and GT & 3&5 become on FSNL. At

07:06hrs. when 160MVA running transformer tripped on Under Frequency at IP Extn.,

the Parkstreet grid got affected due to loss of supply of power of GT, GTs No. 1&2

survived with radial load fed from GT, 220kV bus coupler closed at IP Extn at 07:07 Hrs

and system normalized through Mandola supply. At 07:20 Hrs. GT system got

synchronized with 160MVa Tx.No.1

It was observed that loss of generation at Pragati had occurred due to tripping of evacuating feeders.

NRLDC suggested that as a long term measure LILO of 220 kV Maharani bagh-Lodhi Road line could be carried out. DTL representative stated that the same could not be carried out on account of space constraint at 220 kV Pragati switchyard. Therefore PSC members recommended that as an immediate measure an SPS scheme which will back down generation at Pragati station and shed load upon tripping of evacuating feeders could be implemented. Representative from DTL and PPCL agreed to look into the matter.

C.5.8 Collapse of Kashmir valley and large scale tripping in and around J&K system

Cascade tripping and blackout had occurred in Kashmir Valley on 6th, 18th & 20th December 2010 due to tripping of ICT banks at 220kV Pampore. Representative from

PDD informed that capacity augmentation is being planned at 220/132 kV Pampore and J&K system. However, as an immediate measure PSC members recommended implementation of SPS for automatic load shedding in case of overloading of 220/132 kV ICT bank at Pampore. PSC members requested POWERGRID to assist PDD, J &K by providing suitable technical inputs.

C.5.9 Multiple tripping at 400kV Bareilly (PG) substation at 19.11 hrs on 12th January 2011 SEO) requested representative of NRLDC to brief the sub Committee about the incident. Representative of NRLDC stated that at Bareilly (PG) main circuit breaker of 400kV Bareilley(P.G)-Moradabad-2 was under lockout condition. It is reported that a bus fault occurred during opening of Bus isolator of 400kV Bareilley (P.G)-Moradabad-2 under no load condition for maintainance of CB (i.e. while interrupting only the charging current of line). This led to operation of Bus bar protection and tripping of following 400kV Lines during this incident.

Bareilley(P.G) – Lucknow(U.P) Bareilley(P.G) – Breilley (U.P) Ckt I Bareilley(P.G) – Breilley (U.P) Ckt II Bareilley-Mandola – ckt- I

Although there was no loss of load or loss of generation during the incident, this event requires detail analysis as the fault occurred during maintenance of a lockout CB.

PSC emphasized the need to keep the tie and bus coupler breaker in all substation in 400kV and 220kV closed to avoid loss of adjacent circuit when one line trips. The members agreed that the above practice is to be strictly followed even Bus reactor or EHV line is taken out of service as a part of voltage regulation measure.

C.5.10 Loss of generation at Panipat –Stage-II on 28th December 2010 at 07:26 Hrs Units 5, 6, 7 & 8 at Panipat TPS tripped reportedly due to failure of breaker of Unit 7 & 8.

The Disturbance Recorder (DR), event logger prints & analysis report are awaited from

HPGCL and HVPNL. Several incidents of complete outage of Panipat units have

occurred in the past.

SE (O) asked the representative of HPGCL and HVPNL to submit the detailed report to

NRPC Secretariat /NRLDC so that incident can be taken up in next PSC.

D.1 Back up Earth Fault Setting for AREVA make Numerical Distance Protection Relay(MICOM p442/444

Representative of POWERGRID stated that setting of Back up Earth Fault protection relay can be done depending upon the severity and level of fault. So definite time is best setting for both low & high set of earth faults as it will also not create any confusion in respect to trip time in case of tripping of lines. PSC agreed to take up the matter in next PSC based on the experience of other utilities also.

D.2 Loading of 400kV Tehri-Meerut Line-I & II(Agenda by THDC) Tehri HEP reported that power swing of 20 MW-100 MW had been observed in units whenever generation at Tehri exceeds 650 MW and only one circuit of Tehri -Meerut line is in service. NRLDC requested THDC to intimate the date/time when the power swing phenomena were observed at Tehri station. THDC was also requested to share the recording of voltage, MW, MVAr during the incident as observed at their station. It was suggested that investigations at THDC end may also be carried out particularly in respect of settings adopted in excitation system, Power System Stabilizer (PSS) etc. Representative of THDC stated that they had got a study carried out by consultants and agreed to share the report with NRPC Secretariat / NRLDC in order to discuss the issue in greater detail.

MS, NRPC expressed concern over the non submission of report to NRPC secretariat

and NRLDC. Because of it, matter could not be discussed in detail. He emphasized that

protection issues should be taken seriously for safe and secure grid.

Meeting ended with vote of thanks to chair.

Annexure-I Name of the utilities_________________ Date_____________________

Name of Sub-

station/transmission lines

Protection Setting

Reach & Time Setting by Utility as per the

Philosophy(Yes/No)

If No state the reason with

target date of implementation

Long lines Zone-1

80% of the Protected line, Instantaneous

Zone-2 100% of the Protected line + 50% of the shortest line emanating from the far end bus bar or 120% of the Protected line whichever is higher. Time Setting: 350ms for short lines (≤ 100km ) and 500ms for long lines > 100km.

Zone-3 120% of the protected line + 100% of the longest line emanating from the far end bus bar or 100% of the Protected line + 100% of the longest line emanating from the far end bus bar + 25% of the longest line emanating from the far end of the second line considered, whichever is lower. The zone setting to be limited such that it will not reach into the next voltage level. Time Setting: 1000m sec.

Zone- 3R 25% of the Zone-1 reach. Time Setting: 1000m sec

Lines with Series and other compensations in the vicinity of

Substation

80% of the Protected line. 100ms-time delay for allowing correct distance measurement after the series capacitor is bypassed.

Power Swing Blocking

Block tripping in all zones, all lines. Out of Step tripping to be applied on all inter regional tie lines Deblock time delay = 2s

Protection for broken

conductor

Negative Sequence current to Positive Sequence current ratio more than 0.2(I2/I1 ≥ 0.2) Only for alarm: Time delay = 3-5 sec

Carrier Protection

To be applied on all 400kV and 220kV lines with the only exception of radial feeders.

Back up Protection

1) On 400 & 220kV lines with 2 Main Protections, back up Earth Fault protections alone to be provided. No Over current protection to be applied.

2) On 220kV and lower voltage lines with only one Main protection Back up protection by IDMT O/C and E/F to be applied.

Auto Re-closing with dead time.

Single pole trip and re-closing Dead time = 1.0s. Reclaim time = 25.0s

LBB Protection and bus bar protection

To be applied on all 400kV and 220kV sub stations with the only exception of 220kV radial fed bus bars. LBB Current sensor I > 20% In LBB time delay = 200ms

(Signature of Sub-Station In-charge) (Signature of SLDC Head)

Annexure-II

S.No

Description of line (example)

Name of protection relay(Model/Ma ke)

Parameter of line and Type of conductor

Zone Settings

Features Enable in the Relay & their Details

Parameter(R, Xl, Xc, Conductance, Length)

Type & Configuration of conductor

FFR Power Swing Blocking

Carrier Scheme

B/U Over Current Function

B/U Earth Fault Function SOTF Broken

Conductor A/R Stub Protection

Over- Votage Protection

1 400KV Dadri-Mandola-I Mandola end:

Zone 1 Operation Operation Operation

Operation Operation Operation Operation Operation Operation

e.g. Main-I: REL670 (ABB make)

Reach(%)

ON/OFF ON/OFF

PUR/POR/PBR ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF

400KV Dadri-Mandola-I Mandola end:

Time sett.

Op. Mode First Stage First Stage

time delay for alarm / trip: ....sec

Mode: I> %Ibase

Stage-1 U1>% volts

Zone 2 Zero seq In case of Blocking Scheme; Relay coordination time.... ms

Dir. Mode: OFF/ Non-Direct./FWD/REV


U< % Ubase 1PH/3-PH/ Stage-1 time delay: ....sec

Reach (%)

3U0>%Ubas e I>%Ibase Dead time:.... sec Stage-2

U2>%volts Time sett.

3I0< %Ibase Blocking zones:Z1, Z2, Z3 IDMT IDMT

Reclaim Time: .... sec Stage-2 time

delay: ...sec Zone 3 VTS time delay-

.... Sec I1 (PMS)-...%In

In1 (PMS)-....%In

Reach (%) Un-blocking time

delay...sec t1 (TMS)- ... t1 (TMS)-

Time sett.

Zone 3® Second Stage

Second Stage

Reach (%) Dir. Mode:

OFF/ Non-Direct./FWD/REV


Time sett. Definite time

Definite time I2- ....Amps In2-.... Amps t2(definite

time delay)-....sec

t2(definite time delay)....sec

e.g. Main-II: MICOM (AREVA make)

Status of Bus bar Protection for Northern Region Constituents Annexure-III

State/Constituent TRANSCO/GENCO

Total No. of Sub

Stations/Switchyards

(220 kV and above)

No. of substations/ switchyards

where Bus bar protection is functioning

Remarks

Delhi DTL 26 22 At 220 kV s/stns namely Lodhi Road and Subzi Mandi 220 kV Bus Bar protection is not required. Bus Bar protection at Gopalpur S/stn shall be provided by end of December 2010. At Kanjhawala the scheme is not in service due to wiring problem which is being attend by M/s ABB and shall be completed by January 2011.

GENCO/IPGCL - - Haryana HVPNL 38 10

HPGCL 03 01 Rajasthan RVPNL 74 17

RVUNL 05 - Himachal Pradesh HPSEB 07 03 Punjab PSTCL 53 06 PO No. 2132 dated 21.07.09 has been placed on M/s ABB Ltd for the installation

of bus bar protection schemes at the following five sub stations: 1.220 KV S/Stn Malerkotla 2.220 KV Rajpura 3.220 KV S/Stn Ablowal 4. 220 KV S/Stn Moga

PSPCL 03 03 J&K PDD 06 - Uttarakhand PTCUL 08 08

UJVNL - - BBMB BBMB 19 17 1. 220 kV Ch. Dadri and Hisar S/stn Target is March 2011.

2. Not required for Dhulkote and Jagadhari 220 kC S/stn as it is meshed. 3. Not required for Barnala, Sangrur, Kurukshetra and Delhi as no. of feeders is less than five

Uttar Pradesh UPPTCL 77 15 21 nos for 220 kV are under procurement stage. UVUNL 05 -

POWERGRID POWERGRID 38 38 Central generating Stations

NTPC 11 11 NHPC 09 09 NPCIL 02 02 THDC 01 01

SJVNL 01 01 Total 382 162

Annexure-IV Status of PLCC Link and A/R scheme in 220 KV lines

S.no Name of Line PLCC Status A/R scheme Remarks

1 220KV ALLD-PHOOLPUR PLCC panels are not available

A/R Scheme not available at UPPCL end

A/R scheme available at our end

2 220KV ALLD-REWA RD-I PLCC link is through A/R Scheme not available at UPPCL end


3 220KV ALLD-REWA RD-II PLCC link is through A/R Scheme not available at UPPCL end


4 220KV ANTA-BHIL-I PLCC link is through A/R Scheme not available at Bhilwara end


5 220KV ANTA-BHIL-II PLCC link is through A/R Scheme not available at Bhilwara end


6 220KV ANTA-RAPPC PLCC link is through A/R Scheme not available at both end

7 220KV ANTA-S.MDHPR PLCC link is not through

A/R scheme is in service

8 220KV KNP-MAINPURI PLCC panels are not available



9 220KV KNP-NAUBASTA PLCC panels are not available



10 220KV KNP-PANKI-I PLCC panels are not available



11 220KV KNP-PANKI-II PLCC panels are not available



12 220KV MEERUT-MPURAM-I PLCC link is through A/R scheme is not in service at UPPCL end


13 220KV MEERUT-MPURAM-II PLCC link is through

A/R scheme is not in service at UPPCL end


14 220KV MEERUT-NARA PLCC link is through A/R scheme is not in service at UPPCL end


15 220KV MEERUT-SHTBDNGR PLCC link is through



16 220KV MEERUT-SIMBHOLI PLCC panels are not available



17 220KV RAPPB-CHITT-I PLCC link is not through

A/R Scheme not available at both end

18 220KV RAPPB-CHITT-II PLCC link is not through


19 220KV RAPPB-RAPPC PLCC link is not through


20 220KV RAPPB-UDAIPUR PLCC link is through A/R Scheme not available at both end

21 RRVPNL 220KV BHIWADI(PG)-BHIWADI

PLCC link is not through

A/R scheme is in service


22 RRVPNL 220KV BHIL- KANKROLI(PG)


A/R scheme is not in service at RRVPNL end


23 RRVPNL 220KV KANKROLI- KANKROLI(PG)-I




24 RRVPNL 220KV KANKROLI- KANKROLI(PG)-II




25 RRVPNL 220KV KANKROLI- DEBARI PLCC link is not through



26 DTL 220KV MND-S.WZRBD-I PLCC panels are not available

A/R Scheme not available at DTL end


27 DTL 220KV MND-S.WZRBD-II PLCC panels are not available



28 DTL 220KV MND-S.WZRBD-III PLCC panels are not available



29 DTL 220KV MND-S.WZRBD-IV PLCC panels are not available



30 DTL 220KV MND-NARELA-I PLCC panels are not available



31 DTL 220KV MND-NARELA-II PLCC panels are not available



32 DTL 220KV MND-GOPALPUR-I PLCC panels are not available



33 DTL 220KV MND-GOPALPUR-II PLCC panels are not available



34 DTL 220KV MBAG-SARITAVIHAR

PLCC panels are not available



35 DTL 220KV MBAG-LODHIROAD-I




36 DTL 220KV MBAG-LODHIROAD-II




37 DTL 220KV MBAG-I P EXTN PLCC panels are not available



38 UPPCL 220KV M'PURI-HARDUAGNJ




39 UPPCL 220KV M'PURI-M'PURI(UP)-I




40 UPPCL 220KV M'PURI-M'PURI(UP)-II




41 UPPCL 220KV M'PURI-FEROZBD PLCC link is not through



42 UPPCL 220KV LKO(PG)-SITAPUR PLCC link is through A/R scheme is not in service at UPPCL end


43 UPPCL 220KV LKO(PG)-CHINHAT PLCC link is through A/R scheme is not in service at UPPCL end


44 UPPCL 220KV GORAKH-BARHUA PLCC panels are not available



45 UPPCL 220KV GORAKH-BASTI PLCC panels are not available



46 UPPCL 220KV MEERUT-GAJRAULA PLCC link is through



Annexure -IVA

Sl. No. NAME OF LINE PLCC STATUS A/R SCHEME REMARKS 1. 220 KV ANTA-

BHILWARA-I PLCC link is through.

A/R Scheme commissioned on 17.04.2004.

2. 220 KV ANTA-BHILWARA-II

PLCC link is through.

A/R Scheme commissioned on 17.04.2004.

3. 220 KV ANTA-SAWAIMADHOPUR


A/R Scheme is in service.

4. 220 KV RAPP(B)-CHITTORGARH-I

PLCC link is not through.

A/R Scheme available at both ends & to be commissioned by PGCIL and RRVPNL.

New PLCC Panels are to be commissioned at both ends.

5. 220 KV RAPP(B)-CHITTORGARH-II


A/R Scheme available at both ends & to be commissioned by PGCIL and RRVPNL.

New PLCC Panels are to be commissioned at both ends.

6. 220 KV RAPP (B)-UDAIPUR


A/R Scheme not available at both ends.

New A/R scheme or new distance protection scheme is to be provided at RVPN end.

7. 220 KV BHIWADI(PG)- BHIWADI


A/R Scheme is in service. PLCC panels to be installed at Bhiwadi (PG) end and commissioned at both ends.

8. 220 KV BHILWARA-KANKROLI(PG)


A/R Scheme to be commissioned at RVPN end shortly.

9. 220 KV KANKROLI-KANKROLI(PG)-I


A/R Scheme has been commissioned at RVPN end.

10. 220 KV KANKROLI-KANKROLI(PG)-II

PLCC link is through. A/R Scheme to be commissioned at RVPN end shortly.

A/R Scheme to be commissioned at RVPN end shortly.

11. 220 KV KANKROLI-DEBARI

A/R Scheme commissioned and tested but kept out of circuit

Work of laying of cable for pressure switch of breaker is pending.

Annexure-V

Self Certification by utilities w.r.t. time synchronized through GPS(Frequency six monthly)

Name of Organization Date:_________

Name of Sub-station

Whether GPS clock available at Sub-station(Yes/No)

If No give reason and target date for installation of GPS clock

DRs/ELs wired with GPS clock(Yes/No)

If No give reason thereof and target date for wiring up with GPC clock

Last Testing date of GPS clock

Actual output of DRs/ELs during an event and whether event time was same as other station/RLDC DRs/SOE.

(Signature of Sub-Station In-charge) (Signature of SLDC Head)

Documents

MN.PDF