southern regional power committee - … · a special meeting was held on 06th march 2015 in...

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SOUTHERN REGIONAL POWER COMMITTEE

BANGALORE

Minutes of the Special Meeting on pending protection issues in respect of M/s KPCL held on 06.03.2015:

Introduction

A Special Meeting was held on 06th

March 2015 in Southern Regional Power Committee,

Bangalore to discuss pending protection issues in respect of M/s KPCL. The list of

participants is enclosed at Annexure-I.

Shri S.R.Bhat, Member Secretary (MS), SRPC welcomed Technical Director, KPCL and

other Participants to the Meeting and stated the following:

Cooperation extended by KPCL and KPTCL in the Protection Committee forum was

appreciated.

There had earlier been instances of complete station outages at Sharavathy, Kadra and

Nagjheri HPS, which was a matter of some concern.

Petition No. 374 filed by TANTRANSCO before Hon’ble CERC seeking time extension

for Phase-I and Phase-II activities of Protection Audit Recommendations was heard on

15th

January 2015. All Southern Region Constituents had been directed to file status of

implementation of protection system in their respective system to the Commission by

31.03.2015.

Senior-level Officer could be nominated as Nodal Officer to monitor implementation of

various recommendations pertaining to KPCL stations.

Number of remedial actions were pending for considerable time in respect of KPCL

stations. This Meeting was therefore being conducted to have focused deliberations on

issues in presence of the higher management of M/s KPCL.

Following issues were deliberated in the Meeting:

A. Issues related to Hydro Power Stations in Kali complex

1. Complete outage of Nagjheri power station occurred at 11:09 hrs on 22-02-2015.

KPCL stated that while desynchronizing Unit-3, Y-pole of the circuit breaker got

stuck up and did not open. LBB protection got operated which in turn tripped the

220 kV bus including bus- sectionalizer, and all connected 220 kV lines and

running units at Nagjheri power station.

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It was noted that complete outage of station was not desired. Only one 220 kV bus

should have tripped during the incident. KPCL was therefore requested to kindly

review trip logic for LBB both at Nagjheri and Sharavathy stations within a period

of one month. Further, since it was not clear as to what had initiated LBB, KPCL

was also requested to analyse cause for LBB operation and furnish the same along

with LBB protection scheme by next PCSC Meeting to SRPC.

During discussions it was informed by KPCL that Nagjheri Hydro station was

being operated on a single 220 kV bus. SRLDC and SRPC objected to single bus

operation since it was affecting station reliability and posing a threat to operational

security of grid during a complete outage of station. As per good operation

practice, it was requested to have two bus operation in all stations of KPCL where

two buses with bus coupler/ bus sectionalizer breaker is available. The protection

logic needed to be such that during any bus fault or LBB operation, only the

concerned affected bus should be isolated.

2. Complete outage of Kadra power station occurred at 12:56 hrs on 16-02-2015.

KPCL stated that a B phase to earth fault had occurred on 220 kV Kadra-Kodasalli

line, on account of which Kadra-Kodasalli line breaker tripped at Kodasalli end

while Kadra-Kaiga line breaker tripped at Kaiga end. However, breaker at Kadra

end of Kadra-Kodasalli line did not trip on distance protection on account of failure

of protection DC supply fuse fail. This had led to 220 kV bus-dead condition at

Kadra HPS. During fault, Units-1,2 & 3 were not in service while all four lines

were intact. These breakers were hand-tripped later at Kadra end.

KPCL stated that as part of remedial measures, the faulty fuse had been replaced

and protection DC supply was normalized. KPCL informed that there are two

battery banks (1 & 2), but supply to protection system is availed from one bank

only. Switching between the two battery banks is being carried out manually.

KPCL was requested to provide supply to Main-1& Main-2 relays and Trip Coils

(TC1, TC2) from independent/ separate battery banks. KPCL was asked to comply

with all the recommendations recommended by PSAG-10 at the earliest. KPCL

expressed that there were constraints in this regard, since many of its stations were

old. There would be a need to go for extensive rewiring etc. KPCL was requested

to examine this issue for implementation and furnish a road map for all the stations.

3. 220kV Nagjheri-Kodasalli lines kept opened from Nagjheri end.

KPCL stated that these lines were being kept open as per the instructions of SLDC.

During the course of deliberations, it was felt that these lines needed to be normally

kept in service and taken out only during any specific need based requirement.

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B. Issues related to RTPS and BTPS Thermal power stations

KPCL stated that at RTPS Auto re-close had been enabled and functioning in all

400kV lines except on RTPS- Mahaboobnagar and RTPS-Munirabad lines. Existing

Micromho relays shall be replaced with Siemens make Numerical relays shortly.

Order had been placed on Siemens. At BTPS, Auto re-close was enabled for BTPS-

RTPS line. Shutdown required for other 3 lines for enabling and testing of auto re-

close function. KPCL was requested to complete the same at an early date in

coordination with KPTCL.

C. Compliance of Recommendations of the following Power System Analysis Group

(PSAG) Meetings:

PSAG-3 was held on 04.09.2013 to analyze the multiple trippings that occurred at

Sharavathy HPS on 18-08-2013. Compliance of the pending recommendations is

enclosed at Annexure-II.

PSAG- 6 was held on 05.02.2014 to analyze the multiple trippings at Raichur TPS

on 26-01-2014 and 30-01-2014. Compliance of the pending recommendations is

enclosed at Annexure -III.

PSAG-10 was held on 12.11.2014 to analyze the Grid Disturbances at Kadra,

Kodasalli and Kaiga Power Stations that occurred on 26-09-2014 and 05-10-2014.

Compliance of the pending recommendations is enclosed at Annexure -IV.

It was noted that generally recommendations involving procurement activities were

pending, for which also the steps had been taken to complete by Dec, 2015.

D. Pending Implementation of PCSC Recommendations

Latest status of implementation of recommendations of PCSC meetings relating to

Hydro Stations in Kali Complex and RTPS, BTPS is enclosed at Annexure -V.

It was noted that steps had been taken to implement various recommendations relating

to A/R scheme enabling, replacement of old electromechanical relays with numerical

relays at KPCL Stations.

E. Protection Audit Recommendations (Phase- I & II)

Latest status of implementation of protection audit recommendations (Phase I &

Phase II) as updated on 03.02.2015 is enclosed at Annexure -VI.

F. Action taken for inadequate response of the units of KPCL Stations with respect

to RGMO.

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The status of implementation of RGMO in Hydro & thermal units as furnished by

KPCL is as follows:

*Kadra & Kodasalli units & R&M of 6Th

unit NPH & Bhadra two units

In total RGMO is implemented for 3,111.2 MW (87.88%) in Hydro Units, and for

2,510 MW (92.27%) in Thermal Units. Thus, combined RGMO implementation of

Thermal & Hydro Power stations of KPCL stood at 89.79%.

It was pointed out by SRLDC that RGMO response of Units of KPCL Stations

(especially thermal) with respect to desired quantum was not adequate. Details of

various instances for analysis were being posted in the RGMO web group regularly.

KPCL replied that this was mainly on account of poor quality of coal that thermal

power stations get.

SRLDC pointed out that KPCL’s practice of keeping CMC out at times based on

operational requirements was contrary to Regulations. Further, they should also avoid

wide-valve operation. KPCL was also requested to extend the status points (of

RGMO) to SLDC, for proper analysis and appropriate action.

Vote of Thanks

MS, SRPC thanked Technical Director, KPCL and other Officials from KPCL & KPTCL

for participating in the Meeting. He hoped that with active cooperation, visible

improvement would be witnessed in the near future on these pending protection issues.

X------------------------------------------X------------------------------------------X

Annexure - I

Latest status of implementation of recommendations of PSAG-3 for

the Gird incident occurred at SGS on 18.08.2013

S.N.

Recommendations

KPCL’s Compliances

e Disturbance Recorder facility e-NIT floated through e-portal on 04.02.2015. Pre bid meeting for the bid was held on 19.02.2015

f Providing GPS (Time synchronization) facility

e-NIT floated through e-portal on 04.02.2015. Pre bid meeting for the bid was held on 19.02.2015

g To replace both bus sectionalizing BOCBs with new circuit breakers

LOA issued to M/s. ABB India Ltd. on 12.12.2014. Review of drawings is in progress

Annexure-II

S.N Commitee observations KPCL Compliance

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KPCL shall take action to arrange for GPS time

synchronisation of all EL's and provide DR for all

lines.

Job Order has been issued on M/s Siemens ltd., vide SEEM2/R4GM2/400KV/413 dtd:

02.02.2015 for retrofitting electromechanical relays with Numerical version for 400 KV lines of

Mehabobnagar, Munirabad, and ICT-1 & ICT-2 . Supply of GPS and time synchronization of all

the relays also included in the job order. The numerical Relays will be incorporated with EL &

Disturbance Recorder.

6KPCL shall take action for retrofitting of all old

electromagnetic relays with numerical relays.

Presently Raichur (PG)1&2 liines are already provided with numerical relays. Retrofitting of

static relays with numerical relays for BTPS line was completed on 18-03-2014. Job Order has

been issued on M/s Siemens ltd., vide SEEM2/R4GM2/400KV/413 dtd: 02.02.2015 for

retrofitting electromechanical relays with Numerical version for 400 KV lines of

Mehabobnagar, Munirabad, and ICT-1 & ICT-2.

Obtained the Budgetary offer for retrofitting the electromechanical relays of existing bus bar

protection with numerical version and is under process.

12Recommondations of protection Audit conducted

on 02.11.2012 shall be carried out.

Recommondations of protection Audit are being carried out.The latest status of activities in

phase-1 & phase-2 formats are enclosed here with as Annexure-A&B respectively. Most of

the observations already fulfilled except the activities where procurement is involved.

COMPLIANCES FOR THE RECOMMENDATIONS OF POWER SYSTEM ANALYSIS GROUP (PSAG-6) DURING THEIR VISIT TO RTPS ON 05.02.2014.

Annexure-III

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The PSAG-10 members recommended to replace the Main I (Q21 static

Quadramho relay -SHPM 101) distance protection relays with Numerical relays

having DR and EL features.

e-NIT No. LOT/CEED/EE6/R&M/ Dist.Prot/1416 dtd:

28.07.2014 was floated through e-portal for Supply, Retrofit,

Testing & Commissioning of Numerical Distance protection

relays & GPS for Varahi, Gerusoppa, Kadra & Kodasalli

Power Houses of KPCL. Bid evaluation is under progress.

2The PSAG group also advised KPCL to test the Main II Relay (PZ1000

numerical relay) at the earliest .

Will be completed during last week of March 2015 in

coordination with KPTCL.

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PSAG recommended to make the carrier aided protection functional for 220kV

Kadra-Kodasalli, 220kV Kadra-Kaiga and 220kV Kodasalli-Kaiga lines. In

addition, since most of the faults are seen as high resistance fault, PSAG

suggested to revise the existing PUR to POR scheme for all the lines at Kali

complex.






Hence work shall be taken up in coordination with KPTCL

after installation of new relays.

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The PSAG group noted that most of the faults were in the ‘B’ Phase (of RYB) to

ground faults. The group observed that it may be due to thick vegetation below

Kadra – Kodasalli, Kodasalli - Kaiga line, Kadra – Kaiga line. Hence the PSAG

group members advised to have regular thorough line patrolling and clearing the

corridor (i.e. Right Of Way).

To be implemented by KPTCL

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KPCL informed that installation of GPS for time synchronization of all relays and

other protection devices is under process. KPCL is requested to expedite the

same.






Compliance to recommendations of Meeting of Protection system Analysis Group (PSAG-10) at Kadra, Kodasalli and

Kaiga held on 12th & 13th November 2014 for discussing the Grid Disturbancea occurred on 26.09.2014 and

05.10.2014

Sl. No. Recommendations KPCL Compliances- Status as on 23.02.2015

Page 1 of 2

Annexure-IV

Sl. No. Recommendations KPCL Compliances- Status as on 23.02.2015

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It was observed that Kodasalli – Nagjheri I & II lines were kept open at Nagjheri

end on 26.09.2014, 5.10.2014 & 14.10.2014 during bus dead conditions at

Kodasalli station. KPTCL (SLDC) is requested to clarify /review the issue

To be implemented by KPTCL/SLDC

Page 2 of 2

Annexure-IV

Meeting

No /

Index

Meeting

S.NODetails of Event Date Reason PCSC Recommendations

Utility

Responsible

to

implement*

Status of Recommendation RemarksUpdated Status based on the latest PCSC

meeting discussion - Status as on 10.02.2015

30/I/A 1 RTPS Tripping

incidents and the Spl

meeting held at RTPS

on 13th and 14th

March 2014

Mar-14 Spl meeting held at RTPS on 13th

and 14th

March 2014

The PCSC forum recommended for

replacement of existing electromechanical relays with Numerical

relays.

KPCL (1) e- Tender folated for the retrofit of

existing static relays with Numerical

version for lines M.nagar,M.bad,ICT-1

& 2 -Technical Bid opened & price bid

yet to be opened.

(2) Retrofit of existing bus bar (CAG-34)

with numerical version -Budgetetory

offers obtained and is under process.

1) Order placed on M/s Siemens to replace relays.

The work will be Completed by May - 2015.

2) Retrofit of existing bus bar (CAG-34) with

numerical version -Budgetetory offers obtained and

is under process.

33/II/3 9 400kV

Hiriyur-BTPS line-2

22-05-14 &

23/05/2014

B phase to ground fault had

occurred in line and line auto

reclosed at Hiriyur end but failed

to reclose at BTPS end.

• KPCL: A/R is not yet enabled at Raichur plant.

Recommendation:

The PCSC forum requested KPCL to enable the A/R feature at

RTPS end before next PCSC meeting (i.e. 31st July, 2014.

KPCL A/R at BTPS end will be enabled

during November 2014 end and needs

LC.

1) A/R for 220kV lines enabled already.

2) Shut down of lines availed to commission the

auto reclosing scheme for 400kV lines at BTPS.

3) A/R shall be enabled in next shut down

34/III/1 8 400kV

Raichur-BTPS line

26-06-2014 Transient fault in R-phase.

Line did not auto reclose

Recommendation:

A/R at BTPS end to be made operational within one month

KPCL A/R at BTPS end will be danbled

during November, 2014End and needs

LC

1) A/R for 220kV lines enabled already.

2) Shut down of lines availed to commission the

auto reclosing scheme for 400kV lines at BTPS.

3) A/R shall be enabled in next shut down

35/I/2 1 220 kV KAIGA –

KODASALLY an

220kV Kodasalli -

Nagjheri line

19-07-2014 220kV Kaiga-Kodasalli line

tripped on operation of over

current protection.

It was also reported that 220 kV

Kodasalli-Nagjheri line had

tripped due to fault.

From D.R of KAIGA station it

was observed that the fault

persisted for around 340 ms.

Recommendations:

a) KPCL was requested to send the detailed tripping analysis

report to SRLDC and SRPC.

b) The utilities are requested to send the single Line Diagram / Lay

out plan of the affected Substation/ System.

c) KPTCL /KPCL to review the SOTF settings for Kodasalli –

Nagjheri lines.

d) Resistive reach of the distance relay shall be reviewed to take

care of the high resistance fault.

KPCL (i) As per the proceeds of the PSAG-10

relays will be replaced. Temporarily

aranged.

(ii) SOTF setting already reviewed.

(iii) Resistive reach is calculated and

will be uploaded in the seond week of

Dec.2014.

i) Relays were replaced and wired up. testing &

commissioning shall be completed with the

assistance of KPTCL by last week of , 2015.

ii) Completed.

Iii)Completed

38/GD/3.

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5 GD-1 at Kadra and

Kodasalli hydro power

station

13-11-2014 at

19:31hrs

A fault had occurred in 220 kV

Kadra and

Kodasalli. As A result, de-

energization of

220kV bus occurred at Kadra and

Kodasalli.

Recommendations & follow up:

Numerical Distance

Protection relay in Kadra –Kaiga and Kodasalli –Kaiga.

status of PSAG-10

recommendations within a week’s time.

KPCL All the recommendations of PSAG - 10 are

completed except the following pending issue:

i)e-NIT floated on 28.07.2014 for procurement of

Numerical distance relays & GPS. Bid evaluation

is under progress. The work will be completed by

December - 2015. Hower, as per the

recommendations of PSAG, Relays were

temporarily rearranged, replaced and wired up.

testing & commissioning shall be completed with

the assistance of KPTCL by last week of march,

2015.

KARNATAKA - KPCL

Annexure-V

Annexure-VI

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