Minutes of the 39th Protection Coordination Sub Committee meeting · PDF file ·...

Minutes of the 39th Protection Coordination Sub Committee meeting held on 30.12.2014

SOUTHERN REGIONAL POWER COMMITTEE

BANGALORE

Minutes of the 39th Meeting of

Protection Coordination Sub-Committee Of SRPC held on 30.12.2014

1 Introduction

The 39th

Meeting of Protection Coordination Sub-Committee (PCSC) was held on 30th

December 2014 in the Conference Hall of Southern Regional Power Committee, Bangalore. The list of participants in the PCSC meeting is enclosed as Annexure-I.

Shri S.R.Bhat, Member Secretary (MS), SRPC welcomed the Members and participants to the

Meeting. MS briefed the Members regarding the following points:

PCSC Recommendations

o In the Recently concluded TCC meeting, it was emphasized that recommendations

of Protection Coordination Sub Committee and various Special meetings need to

reach logical conclusion within a time frame.

o SRPC Secretariat had circulated the pending recommendations (from 30th

to 37th

PCSC meetings) to the constituents. They were requested to submit the reply, as on

date, for pending recommendations in the same format as circulated for updation.

o Efforts of KPCL, KPTCL, NLC TS Exp-1, and Srisailam RB were noted and

appreciated for submitting written communication to SRPC on completed

recommendations.

o It is a matter of concern to note that some of the remedial measures for the trip

events during July and August, 2014 are still pending. In order to close the event

from the pending list, Constituents were requested to communicate the remedial

measures taken for those incidents. It was also informed to every Constituent to

adhere to timely updation of remedial measures taken for each incident.

Protection suite software

o Constituents are aware that two lectures were given by M/s PRDC, Bangalore at

SRPC on “Protection Suite” software package (on 30.9.2014 during 36th

PCSC

meeting, and also on 11.12.2014).

o “In principle” approval was expressed by constituents for the procurement of

software package, through PSDF, during the recently concluded SRPC meeting.

The constituents are requested to provide their written consent and also indicate

their requirements to finalize the formalities in this regard.

Appreciation for KSEB

o The effort of Mr. Jayarajan C.N, Executive Engineer, KSEB were appreciated since

he had circulated a tutorial note on “Suggestions for providing settings for High Set

Earth fault relay on HV side of Generator Transformer (with Star connection on HV

side and Delta connection on LV side)” to all Members. The note would be

discussed in the next meeting of PCSC.

Minutes of the 39th Protection Coordination Sub Committee Meeting held on 30.12.2014 Page 2

2 Confirmation of the Minutes

The Minutes of the 38

th PCSC meeting held on 27-11-2014 were confirmed since no

comments had been received from the constituents.

3 Grid Disturbances (GD)

3.1 GD-1 at Upper Sileru Power Station of APGENCO

(i) Date and Time of Event 23-11-2014 at 17:45hrs, 22-12-2014 at

22:15 hrs

(ii) Location Upper Sileru Power Station

(iii) Plant and/or Equipment

directly involved

All connected 220kV feeders at Upper

Sileru PowerStation.

(iv) Reported Disturbance /

Fault

As per report, While synchronizing the

Unit # 1 to the grid, Differential protection

was acted and LBB is initiated due to trip

from Differential Protection, it is not

extended to the breaker unit.

(v) Generation Loss 120 MW on 22-12-2014

(vi) Category GD-1

3.2 GD-1 at Upper Sileru Power Station of APGENCO

(i) Date and Time of Event 24-12-2014 at 22:40 hrs

(ii) Location Upper Sileru Power Station

(iii) Plant and/or Equipment

directly involved

All connected 220kV feeders at Upper

Sileru Power Station.

(iv) Reported Disturbance /

Fault

As per report, While desynchronizing the

Unit # 4 from the grid, pole discrepancy

was acted and LBB is initiated as Unit

Breaker is not tripped.

(v) Generation Loss Nil

(vi) Category GD-1

Deliberations on Sl. no. 3.1 & 3.2:

APGENCO:

Both synchronizing and desynchronizing activities of various units resulted in tripping

of units and lines. Tripping was attributed to activation of LBB of the unit circuit

breakers.

KSEB:

Zero sequence compensation should be enabled.


NTPC:

There are two inputs for the calculation of CT secondary parameters, internal and

external values. It shall be tried using the internal input values for the calculation.

WAVE BLK signal is to be enabled in order to block harmonics effect on the

differential relays during synchronization.

SRLDC:

It is recommended to have a Sub-committee Meeting at Upper Sileru for analyzing the

disturbances that happened on 23.11.2014, 22.12.2014, and 24.12.2014 since adequate

data was not submitted for the trippings during November-December, 2014 that had

resulted in complete station shutdown.

MS:

A meeting of the Protection System Analysis Group – PSAG (comprising members

from NTPC, KSEB, SRLDC, APGENCO, APTRANSCO, and SRPC) would be

conducted during the period December, 2014 – January, 2015 at Upper Sileru, AP for

the disturbances that occurred during the period November - December, 2014.

4 Grid Incidences (GI)

The Grid Incidences that had occurred during the period of November–December, 2014

were discussed in the PCSC meeting.

Details (deliberations and recommendations) of the Meeting are enclosed herewith as Annexure-II.

5 Compliance of Hon’ble CERC orders

5.1 Petition No. 146/MP/2013 with I.A. 36/2013 Order dated 20.02.2014

Deliberations & Follow up:

In the PCSC meeting, timely compliance of the above orders was highlighted.

Periodicity of Reporting was also discussed and the constituents were requested to

kindly submit the progress of implementation to SRPC and SRLDC as specified in the

Order dated 20th

February, 2014 of Hon'ble CERC.

Issue regarding non-furnishing of reports such as FIR / Trip Analysis Report, EL, DR,

etc. was also highlighted.

SRPC vide letters dated 4th

and 19th

December 2014 had taken up the issue under Clause

1.5 of IEGC.

It was pointed out that the above reports are to be submitted / uploaded on SRLDC web

application within 24 hours as mandated under IEGC / CEA Regulations.

Recommendations

a. All the constituents were requested to submit the updated status of the compliance

(those who have not completed recommendations mentioned in the Phase I and

Phase II) to SRPC Secretariat at the earliest.


b. The following constituents are to submit the updated status of filing of

petition/affidavit to SRPC Secretariat at the earliest:

APTRANSCO

5.2 Petition No. 167/Suo- Motu/2012

Petition No. Order/ROP Date

Order Description Report to be submitted by respondents.

Periodicity of Reporting to CERC

167/Suo-

Motu/2012 O : 22.02.2014

RPCs shall ensure that the

approved philosophy is adopted

by all users.

SR Constituents As and when

167/Suo-

Motu/2012 O : 22.02.2014

We direct ISTS licensees to

submit details of updated distance

protection relay setting of all

inter-regional lines with

POSOCO & RPCs.

PGCIL & ISTS

Licensee latest

by 04.04.2014

To be collected

167/Suo-

Motu/2012 O : 22.02.2014

The Commission directs all

SLDCs to install/activate sound

recording system in their control

rooms within three months from

the date of issue of this order.

SLDCs To be followed

Deliberations:

In the PCSC meeting, timely compliance of the above order was highlighted.

Periodicity of reporting was discussed and the constituents were requested to submit the

progress of implementation to SRPC and SRLDC as specified in the Hon'ble CERC Order

dated 22.02.2014.

5.3 Petition No. 263/MP/2012

Petition No. Order/ROP Date

Order Description Report to be submitted by respondents.

Periodicity of Reporting to CERC

263/MP/2012 O : 19.12.2013

SRLDC and SRPC of

implementation of quantum of

relief by AUFR as per table

above and proper functioning of

df/dt relays within one month of

issuing this order.

Certified copy

sent to SR

constituents

-

263/MP/2012 O : 19.12.2013

SLDCs are directed to map these

relays on the SCADA system

within three months of issuance

of this order.

SRPC/SRLDC shall submit a

CERC Before 19.04.2014


compliance report in this regard

within four months of issuing this

order.

Deliberations:

In the PCSC meeting, timely compliance of the above order was highlighted.

Periodicity of Reporting was discussed and the constituents were requested to submit the

progress of implementation to SRPC and SRLDC as specified in the Hon'ble CERC Order

dated 19.12.2013.

6 Special Protection Scheme (SPS)

I.Kolar HVDC run back SPS The status of implementation shall be informed to the PCSC forum.

II.Review of Nagjheri SPS

Recommendation

PCSC forum requested KPTCL to implement the proposed SPS scheme at the earliest.

7 Pending Protection issues: status

Pending protection issues were discussed in the Meeting. The constituents were

requested to send /update the recommendations of the previous PCSC meetings on or

before the next PCSC.

It was decided in the meeting that the previous recommendations would be circulated to

then constituents and they would update the compliance status.

The follow up issues would be discussed before taking up the other agenda items.

Recommendation& Follow up

The status of pending recommendations as on 10.12.2014 is enclosed as Annexure III.

The constituents were requested to send the status of compliance latest by 27.01.2015.

8 Dynamic study data: submission

All SLDCs were requested to direct the embedded IPPs connected at 220 kV and above

voltage level to submit completed dynamic study format to SRPC, Secretariat.

Deliberations

Constituents were requested to submit the Dynamic study data at the earliest.

9 Configuration changes: informing to PCSC forum

It had been agreed in the PCSC forum that any change in the system configuration ( i.e.

addition of Generating Units, Capacitors, Reactors, LILO etc) would be highlighted


and brought to attention of the forum during PCSC Meetings .

This would enable utilities to review their protection settings and to have better

protection coordination in the Southern Region.

All constituents were requested to submit the change in the configuration in their

system if any to the PCSC forum on a monthly basis.

10 Other Protection Issues

10.1 Update on Tripping Monitoring System web page by SRLDC

SRLDC informed that some modifications have been done on SRLDC’s webpage for

reporting trip events. A screen snap shot of the modified (in circle) webpage is given here

with some remarks.

10.2 Adhering to Safety Regulations during construction and O&M

SRPC informed the Members that during the construction and O&M activities of electric

plants and lines, safety measures as prescribed in the CEA Regulations mentioned below

have to be followed. 1. Central Electricity Authority ( Measures relating to Safety and Electricity Supply)

Regulations, 2010 (http://www.cea.nic.in/reports/regulation/regulation_elec_safety.pdf)

Before year 2010, it was known as Indian Electricity Rules-1956.

2. Central Electricity Authority (Safety requirements for Construction, Operation and

Maintenance of Electrical Plants and Electric Lines) Regulations, 2011 (http://www.cea.nic.in/reports/regulation/reg_elec_plants_lines.pdf)

http://www.cea.nic.in/reports/regulation/regulation_elec_safety.pdf

http://www.cea.nic.in/reports/regulation/regulation_elec_safety.pdf

http://www.cea.nic.in/reports/regulation/reg_elec_plants_lines.pdf

http://www.cea.nic.in/reports/regulation/reg_elec_plants_lines.pdf


SRPC stressed on the need for training of the personnel involved in the work as stipulated

in the CEA regulations. Certain excerpts from CEA Regulations are as follows:


11 Date & Venue of the next Meeting

40th

PCSC meeting would be conducted on 29.01.2015 (Thursday) in SRPC,

Bangalore at 10:30am.

41st PCSC meeting would be conducted on 26.02.2015 (Thursday) in SRPC,

Bangalore at 10:30am.

*****

1

ANNEXURE-I

2

ANNEXURE-I

3

ANNEXURE-I

4

ANNEXURE-I

5

ANNEXURE-I

ANNEXURE - II

1

The following trippings on account of various faults, over voltage condition,

and non-operation of auto-reclose scheme were discussed in the 39th

PCSC

Meeting.

I. Grid Incidents (GI)

Sr.

No.

Details of Events Date and

Time

Reason Category

1 Tripping of 400kV

Gooty-Somanahalli

22-11-2014

at 16:50 hrs

Line tripped due to

suspected PLCC

Mal-operation at Gooty

end.

GI-2

Deliberations:

o It is noted from FIR that:

o FSC (Fixed Series Compensation)-1 & 2 at Gooty end were in service.

o Somanahalli end send DT to Gooty end.

o PGCIL:

o The PLCC panel equipment ETI-21 was suspected to have mal-operated because of

bad weather which caused some drift in carrier frequency (45-85 kHz).

o Protection Coupler of PLCC would be checked.

o SRLDC:

o As the equipment is older at Gooty, either retrofitting or optical fiber could be tried to

prevent the PLCC mal-operation problem.

Recommendations:

Retrofitting of the relay or installation of Optical Fiber cable is recommended by PCSC

forum to PGCIL.

2 Tripping of

400Kv Ghanapur-

Mamidipally

line

22-12-14

at 10:52 hrs,

24-12-14 at 11:32

hrs,

24-12-14 at 16:16 hrs

Due to PLCC Mal-operation at

HYD SS end DT received at

MMPLY end and line got tripped.

GI-2

Deliberations:

TSTRANSCO:

Retrofitting of the relay was done recently. But still the DT signals were sent 3

times without any fault.

ANNEXURE - II

2

Recommendations:

PGCIL is requested check up with the manufacturer to resolve the issue and submit

remedial measures to PCSC forum.

3 Tripping of 400/220 kV

ICT-3 at TALAGUPPA

29-11-2014 at

17:45 hrs ICT -3 tripped due to operation

of capacitive trip device due to

DC fail.

GI-2

Deliberations:

PGCIL:

CTD (capacitor trip device) is generally used for lines.

Tripping the CB at low gas/air pressure (i.e. lock out pressure) instead of locking out

is against the protection philosophy.

SRLDC:

If SF6 gas leaks out, then trip is not possible.

KPTCL:

There was no fault indication. Failure of both the sources of DC supply - DC1 & DC2 caused the CTD to trip the

220 kV CB of the ICT-3.

CTD is charged by the DC the source; CTD will not operate for one DC source

failure.

During the winter, as the gas contracts low pressure alarm may be generated.

According to OEM, at lock out pressure of gas, the CB could be tripped.

Alarm-Trip-Block is the sequence of control circuit events in case of low pressure of

gas/air.

Corrective action: The faulty control circuitry that caused the failure due to suspected ingress of

moisture has been rectified now.

4 Tripping of

400/230 kV

ICT-IV at

ALAMATHY

28-11-2014 at

15:04 hrs

&

9-12-2014 at

13:24 hrs

HV Breaker got tripped with Winding

Temperature Trip indication. GI-2

Deliberations:

TANTRANSCO:

The transformer was idle charged and without any load; the winding temperature

indicator (WTI) was reading 45°C.

ANNEXURE - II

3

5 Tripping of 400/220kV

ICT-2 at Hoody

substation of KPTCL

01-12-2014 at

11:46 hrs Suspected mal-operation of 220kV side R-

phase over current relay GI-1

Deliberations: KPTCL:

Hoody substation is now under R & M work.

ICT’s tertiary winding O/C relay got activated which tripped the transformer.

During the O & M work, forceful closing of the door of the relay panel operated the

sensitive/delicate O/C relay contacts that resulted in tripping.

Recommendations:

PCSC forum recommended KPTCL to replace the relay with a different make.

KPTCL was also requested to train the O&M personnel adequately before

performing any maintenance works to avoid such unwanted trippings.

6 Tripping of 400 kV

Neelamangala-Hoody

line -2

04-12-2014 at 16:42

hrs Line tripped due to relay mal-operation GI-2

Deliberations:

KPTCL:

Mal operation of PLCC at Neelamangala end caused the breaker to trip at

Neelamangala end.

Corrective Action: PLCC protection coupler has been replaced at Hoody and Neelamangala

ends.

At the marshalling box of 400 kV isolator, there was a DC leakage.

DC leakage caused WTI of the transformer to trip the circuit breaker.

Corrective action: Report will be sent after rectification.

Recommendations:

TANTRANSCO is requested to send the compliance report after the rectification

work.

ANNEXURE - II

4

7 Tripping of 400kV

Thiruvelam-

Kalivanadapattu line-1&2

10-12-2014 at

1:08 hrs

Over voltage protection operated during

B-ph fault in 220 KV Taramani –KVPT

line.

GI-2

Deliberations:

It is noted that 220 kV Kalivanthapattu – Taramaniline tripped on B-phase earth fault; and during

that time Kalivanthapattu– Thiuvallam 1 & 2 got tripped on over voltage; Kalivanthapattu end

sent DT to Thiuvallam end.

PGCIL:

Time grading for the over voltage trip of the lines are 5 & 7 seconds, which are in line

with the suggested grading.

Corrective action:

The drop-off to pick up ratio was at 96% prior to tripping has been now corrected to 99%.

8 Tripping of 220kV

Chikodi-Talandage&

220kV Chikodi-

Mudshingi lines

01-12-2014 at

16:17 hrs

Talandge line tripped at Chikkodi

end on Back up protection.

Meanwhile Mudashinge line tripped

at Maharastra end on DPR,Zone-2.

GI-1

Deliberation:

KPTCL:

Sugar cane field caught fire beneath the Talandge line near Koobanahalli village

limits.

Chikodi - Talandge line tripped:

o at Chikkodi end on Back up protection (DEFR), and

o atTalandage end on DPR Zone-1.

MeanwhileChikodi - Mudshinge line tripped at Mudshingeend on DPR, Zone-2.

220kV Talandge and Mudashingestations are connected radially with the

Karnataka system and feeding the loads of 100MVA Trafo-1 at Chikkodi and

some loads of Belaguam through Chikkodi-Belgaum line-1.

KPTCL informed that DR was not received from Maharashtra.

Chikodi Mudshinge

Talandage

DPR,

Z-2, 72.2 km

DPR,

Z -1, 11

km

b/u protection

(DEFR)

Fire

Maharashtra Karnataka

ANNEXURE - II

5

SRPC:

Need to check the operation of back-up (DEFR) protection at Chikodi end

instead of distance protection (DPR) on 220kV Chikodi-Talandage line.

Recommendations:

KPTCL was requested to get tripping report details from the stations (i.e. Talandage,

Mudashinge and Chikodi).

9 Tripping of HVDC

pole-2 of Talcher -

Kolar

16-12-2014 at

10:03hrs As reported pole-2 tripped due to

problem in valve cooling system.

SPS signal-1 & 3 had operated

resulting in load shedding of 1258

MW.

GI-2

Deliberations:

PGCIL:

There are two cooling A/C pumps which are controlled individual MCBs. The two pumps

are with back up UPS power supply.

One of the pumps got tripped on blocked rotor/standstill protection; subsequently the other

pump also got tripped as there was no supply available to that pump.

Corrective action:

MCBs of the pumps would be tested during the pole shutdown (on 14, 15, 16 of January,

2015) and send the feedback to PCSC forum. If the pumps fail during testing, they would

be replaced.

SRLDC:

As SPS operated, Kerala did not receive the signal to shed the load. Need to

perform one more mock test for the SPS operation.

Recommendation:

PGCIL shall test the pumps during pole shutdown and submit the report to PCSC

forum.

PGCIL shall conduct mock test for SPS signals to Kerala and submit the

feedback to PCSC forum.

ANNEXURE - II

6

10 Tripping of

Neelamangala- Hoody

Ckt-1&2 along with

Hoody ICT-2

13-12-2014

at 09:45hrs It was reported that bus bar protection

got operated at Hoody substation. GI-2

Deliberations:

KPTCL:

Operation of Bus Bar Protection (BBP) got occurred at Hoody substation

while changing Kolar-II control cables from old C&R panel to new C&R

panel.

Due to some cable problem inside the panel, trip signal of BUS-1 became

high. This resulted in the spurious operation of BBP of BUS-1.

Recommendations:

Reason for this operation of bus bar protection relay and remedial measures

shall be submitted to PCSC forum.

II. Auto-reclose (A/R): Failure/Non-Operation during Transient Fault

The following tripping incidents, due to non-operation of Auto-Reclose function, were discussed

in the Meeting.

S.No Element Date &

Time

Reason PCSC Deliberations /

Recommendations

1 Tripping of 400kV

Talaguppa-

Neelamangala line

09-12-2014

at 15:03 hrs Line tripped on R-

phase to

earthfault.

Line did not auto

reclose.

KPTCL: As OPGW works were going

on, auto-reclosure was kept in

non-auto mode.

2 Tripping of 220kV

Yerandahalli-Hosur

line

10-12-2014

at 15:25 hrs

B-phase to earth fault

had occurred in line

and line did not auto

reclose.

The issue was noted.

ANNEXURE - II

7

III. Over Voltage Tripping The following over voltage tripping incidents were discussed in the Meeting.

Sl.

No.

Element Date &

Time

Reason PCSC Deliberations/

Recommendations

1 Tripping of 400kv

VTPS-Satenapalli line-

1 &2

11-12-2014

at 23:42 hrs

Both lines

tripped on over

voltage and over

voltage

protection

operated at

VTPS end.

The reason for

simultaneous

tripping of both

lines needs

further

investigation and

is over voltage

grading provided

for both the

lines.

Deliberations:

Time grading for the over

voltage trip of the lines are 9

& 7 seconds, which are in line

with the suggested grading.

Recommendations:

PCSC forum recommended

APTRANSCO to check up the

drop off to pick up ratio of the

Overvoltage relay and correct

it (if needed).

2 400kv VTPS-

Satenapalli line- 2 15-12-2014

at 23:22 hrs

14-12-2014

at 23:10 hrs

13-12-2014

at 23:36 hrs

13-12-2014

at 00:01 hrs

11-12-2014

at 23:42 hrs

10-12-2014

at 23:55 hrs

Tripped on over

voltage.

The drop off to

pick up ratio and

grading in over

voltage protection

needs to be

verified.

3 400kV VTPS-

Satenapalli line- 1 11-12-14 at

23:42 hrs

ANNEXURE - II

8

4 Tripping of 765kV

Raichur-Kurnool line

and Kurnool NPS

line2.

12-12-14 at

21:56hrs Lines tripped on

operation of over

voltage stage-1.

765kV Raichur-

Kurnool tripped

at Kurnool end

only.

Deliberations:

PGCIL informed that at

Raichur end, LA failed;

Earthing strip of the LMU

(Line Matching Unit) of

PLCC protection system

has been now replaced by

copper strip.

PCSC forum decided to

address the following two

issues for 765 kV lines:

(i) Time grading for the over

voltage trip of 765 kV

lines have to be

formulated.

(ii) Adequate and effective

drop-off to pick up ratio

of the O/V relays of the

line has to be ensured.

*****

S.No Meeting No / Index

Meeting S.NO

Details of Event Date Time Reason PCSC Recommendations Utility Responsible

to implement*

Status of Recommendation

Status as on 10.12.2014 Remarks

1 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.

- Pending

2 30/II/1 2 Tripping of 400kV Srisailam-Satenapalli line-1&2

17-02-2014 @ 16:54 & 17:45 hrs

Tripped due to PLCC mal-operation. Status of D.R/ EL at Satenapalli

· TSGENCO informed that the line tripped at Satenapalli end due to receipt of continuous direct trip signal from Srisailam. TSGENCO also informed that the issue has been rectified on subsequent day and no issues were observed. The new relay would be in place within 11/2 months.

TSGENCO Yet to be informed Pending

3 30/II/2 3 Tripping of Udumalpet-Arasur line-2

17-02-2014 @11:57 hrs Line tripped at Udumalpet end only. It was reported that there was auto reclose lock out due to oil leak in breaker. The reason for line tripping due to A/R lock out needs further investigation.

· The PCSC forum requested TANTRANSCO/PGCIL to send the analysis report of the incident at the earliest.

PGCIL informed

PGCIL informed that theincidence has happenedduring Main CBmaintenance. AR scheme hasbeen modified to avoid suchrepeated trippings

Completed

4 30/II/8 4 Tripping of NCTPS-Alamathy-1 & NCTPS-S.V.Chatram-1

26-02-2014 @ 16:25 TANTRANSCO informed that tripping occurred when the Almatti CB was charged at NCTPS end after the maintenance.SRLDC enquired about the commissioning of DR and EL at NCTPS.TANTRANSCO informed that only standalone DR and EL are not yet installed, but relays have built in DR/EL features.TANTRANSCO informed that issue was taken up with the OEM.

TANTRANSCO TANTRASNCO informed that DR and EL yet to be commissioned

Pending

* If any discrepancy It may please brought to the notice of SRPC Secretariat at at the earliest.

1

ANNEXURE-III

5 30/II/12 5 Tripping of Raichur-Raichur(PG) line-1&2

05-03-2014 @ 3:39 hrs 400kV Raichur-Raichur(PG) line-1 auto reclosed and tripped. Line-2 tripped from Raichur end only

The PCSC forum requested send the complete tripping analysis report to the PCSC forum

KPCL/SRTS I (PGCIL)

Yet to be informed Pending

6 31/I/2 1 400 kV NEYVELI TS 1 (EXP) - TRICHY

24-Mar-14 at 4:20hrs B phase to earth fault. DT received from Neyveli end

It was suggested to check the protection settings. NLC During the 38th PCSC,NLC informed that by 1st week of December 2014 the Relay would be replaced.

NLC informed that ,It is programmed to change the Main-1 protection relay in the third week of Dec-2014.Protection settings will be rechecked again before commissioning the relay.

Pending

7 31/I/5 2 400 kV HASSAN - UPCL 2 28-Mar-14 at 12:52hrs From D.R of UPCL end it is observed that earth fault protection of line got operated which resulted in tripping of line.

· It was noted that Hassan – UPCL lines tripped on account of back up earth fault protection.UPCL said that more line trippings (usually between 12.00 and 3.00 PM) are due to bamboo/ rubber trees on the right of way. UPCL said that relays would be tested by M/s Alstom shortly.Effective patrolling of the line would be carried out as decided in the meeting held by concerned utility officials. PGCIL suggested that as many trips are attributed to high resistance fault, carrier aided directional scheme is required. UPCL to adopt IDMT characteristics for back up earth fault protection.

UPCL/ KPTCL /PGCIL

Yet to be informed. PGCIL,SRTS II informed that there is no protection issues at Hassan end.

Pending UPCL/ KPTCL

8 31/I/9 3 Tripping of 400kV Vallur-Kalavindapattu line-1&2

13-Apr-14 at 21:06 hrs Failure of B-Phase Current transformer in Vallur Main bay at Kalavindapattu substation which resulted in a bus fault in 400kV bus-2. 400kV Vallur-Kalavindapattu line-2 also tripped during the incident.

PGCIL informed that the tripping occurred due to possible configuration

problem with LBB which is having two features –

common trip (for within bay) and inter-trip (for all bays) and the problem had been

rectified. The complete scheme was also checked subsequently during bay

extension at Kalivanthapattu

9 4 Tripping of 400 K v KLVDPT - VALLUR 1

14-Apr-14 at hrs Line failed due to auto reclose at Vallur end

10 31/II/1 5 400 kV GHANAPUR - MAMIDIPALLY

20-Mar-14 at 15:20 hrs Line tripped at Ghanapur end only on Direct trip receive

The PCSC forum requested TSTRANSCO/PGCIL to check the PLCC system at their respective ends.

TSTRANCO / PGCIL

informed. TSTRANSCO informed that , spurious signal generated in

PLCC panel at 400KV of PGCIL Ghanapur SS end only. No direct trip signal

was sent from 400KV Mamidipally Substation.

Pending (PGCIL)

Completed· PGCIL informed that the tripping occurred due to possible configuration problem with LBB which is having two features – common trip (for within bay) and inter-trip (for all bays) and the problem had been rectified.

TANTRANSCO / PGCIL TANTRANSO informed that Auto reclosure

commissionedfor all feeders on

24.07.2014

2

ANNEXURE-III

11 32/I/1 1 Tripping of HVDC Gazuwaka pole-1 and 400kV Jeypore-Gazuwaka line-1

21-04-2014 at 22:40 hrs Mal operation of LBB of Tie breaker (Gazuwaka end) of HVDC Gazuwaka pole-1 and 400kV Jeypore-Gazuwaka line-1 caused the tripping

PGCIL shall submit a detailed report on the tripping incident by 6th

June, 2014.PGCIL Yet to be informed. Pending

12 32/I/3 2 400kV JSW-Guttur line 29-04-2014 at 15:38 hrs Y-phase to earth fault had occurred in line. Reason for non/ unsuccessful auto reclose along with reason for operation of DEFR at Guttur needs further investigation

On account of transient fault, JSW-Guttur line was tripped at Jindal end by distance protection and at Guttur end by DEFR. SRLDC:• Operation of DEFR not desired for transient fault.• Auto reclose (AR) not operating for DEFR is a correct & desired operation.• Un-matching magnitude of fault current of 11KA @ JSW end and 1.6 kA at Guttur end could not be possible. KPCL:• Due to high fault resistance (i.e. 140 ohm primary), the current was less (i.e. 1600A) which could not invoke distance protection (21).• DMT with 1.5 sec (which is more than zone-3 timing) is adopted for DEFR; had IDMT been adopted, it would not have tripped. JSW:• Fault current was 11 kA at Jindal end and distance protection along with auto reclose acted on the JSW-Guttur line.

JSW / KPTCL Yet to be informed. Pending

13 31/I/8 3 Tripping of 400kV Kolar - TVVLM line & 400kV Sriperumbudur-Tiruvalum line

11-Apr-2014 at 20:18

B phase CT failure in 400kV Spdr- Tiruvalum line at Tiruvalum end which resulted in bus fault. Complete outage occurred as lines were connected to one 400kV bus.

· It was noted that Kolar-Sriperumbudur line has LILO at Tiruvalum.SRLDC said that though Tiruvalum- Sriperumbudur tripping was in order, Tiruvalum-Kolar line would not have tripped. The tripping of Tiruvalum-Kolar line was due to the absence of tie-CB at Tiruvalum.It was noted that as of now, Kolar and Nellore (1 & 2) feeders are being operated without tie-CB in the one and half breaker scheme at Tiruvalum.PGCIL informed that tie-CBs for Nellore-1 & 2 lines are being taken into service first time today i.e. 29.04.2014.SRLDC expressed concern over PGCIL operating the 400 kV lines without tie-CBs and not informing Regional Load Dispatcher and stated that the absence of tie-CBs came to its notice in the PCSC meeting only.• It was stated by SRLDC that line operation with single CB is against the protection philosophy. MS i/c, SRPC also expressed his concern over the operation of Line with single CB and not informing the same to SRLDC. The Regional Load Dispatcher would not be kept in dark regarding tie-CB and it is not good for the system. He urged PGCIL to keep SRLDC informed of if any change in the scheme or absence of power system element /equipment.

PGCIL informed. PGCIL informed that Duringthe PCSC meeting, it wasinformed that all theelements were on both mainand tie CBs. In the meeting,it was also informed that it isnot complete outage, otherbus was in service andChittoor I & II and busreactors were in chargedcondition.

Completed

3

ANNEXURE-III

14 32/I/7 4 Tripping of 400kV Raichur(PG)-Gooty line-1&2, 400kV Raichur-Raichur(PG) line-1

03-05-2014 at 16:52 hrs Y-B phase fault had occurred in 400kVRaichur-Gooty line-2. Distance protection over-reached at Raichur TPS end for 400kV Raichur-Raichur (PG) line-1 and At Gooty end for 400kV Raichur-Gooty line-1.

SRLDC:•POR scheme is already there.•Time stamps of events in SOE sent to SRLDC is appeared to be incorrect.•SOE of Raichur is not being sent to SRLDC.•Even after 20 days of issuing notice, PGCIL has not yet replied on testing the lines. PGCIL: Gooty 1 & 2 lines were tested and corrected on 11.5.2014 and Raichur lines would also be tested .

PGCIL Yet to be informed. Pending

15 32/I/10 5 Tripping of 400kV Kudankulam-Madurai line

05-05-2014 at 23:47 hrs Y-phase to earth fault had occurred near to Kudankulam. R-and B-Pole of breaker tripped 750ms after tripping of Y-Pole breaker at Madurai. The carrier aided protection at Madurai end and healthiness of PLCC link needs to be tested

Recommendations NPCIL is requested to inform the PCSC forum regarding the implementation schedule of auto reclose feautre at Rajasthan Atomic Power Plant and KKNPP.

NPCIL PGCIL informed that the complete AR scheme was checked during next opportunity shut down and found working satisfactorily.

Kaiga GS response: The matter of implementation of Auto Reclose feature for 400 kV transmission lines at KGS-3&4 is referred to NPCIL HQ. Based on its satisfactory performance at RAPS-5&6 units, consent will be given by HQ for its implementation in KGS-34 AND ACCORDINGLY SCHEDULE WILL BE PROVIDED FOR ITS IMPLEMETATION.

Pending

16 32/II/6 6 400kV Ramagundam-Chandrapur line – 1

28-04-2014 at 14:46 hrs R-phase to earth fault had occurred in line. Line did not auto reclose

NTPC:•Auto reclose feature is not in service on Ramagundam – Chandrapur line due HVDC back-to-back link at Chandrapur. It was informed that HVDC link faces problem if there is auto-reclose feature. •It was informed that nowhere in the country, 3-phase auto reclose is implemented for the lines at generating station. •NTPC informed that sending DT for the earth fault at Chandrapur end is not a correct operation. PGCIL:•Problematic protection coupler is to be replaced for the line.•3-phase auto reclose feature is implemented on the Gazuwaka-Jeypore which is having HVDC back-to-back at Gazuwaka. Synchro check is done and 1-phase auto reclose is converted into 3-phase auto reclose. SRLDC:•3-phase auto reclose feature implemented on Gazuwaka-Jeypore line is not known to SRLDC and it is not clear under what conditions it was approved. However, SRLDC recommends 1-phase auto reclose. MS i/c:•PGCIL should come back with a plan for implementing auto reclose feature on Ramagundam – Chandrapur line.

PGCIL / NTPC Yet to be informed. Pending

4

ANNEXURE-III

17 32/II/7 7 400kVGuttur-Narendra line-2

30-04-2014 at 20:19 hrs R-phase to ground fault. Line auto reclosed at Narendra end but failed to reclose at Guttur end

KPTCL: • Bays are maintained by PGCIL at Narendra.PGCIL• Relays were checked individually but the scheme of auto reclose is not yet checked. It will be done after taking the line shutdown.

PGCIL / KPTCL informed. PGCIL informed that CB pressure switch problem observed and the same was rectified.

Completed

· 22-05-2014 at 15:02 hrs

07-06-2014 at 19:44hrs

19 33/I/4 2 Tripping of 400kV Nellore pooling station-MEPL line

23-05-2014 at 14:11 hrs Line tripped at Nellore pooling end only due to direct trip receive from MEPL end.

FIR: At NPS end, line tripped after receiving DT. At MEPL end, there was DC earth fault.

Deliberations:The issue was noted.

PGCIL /MEPL Yet to be informed. Pending

20 33/I/5 3 Tripping of 400kV Nellore-Nellore pooling line-1&2 and tripping of 400kV Nellore-SEPL line

23-05-14 at 17:01hrs & 17:03 hrs

400kV Nellore-Nellore polling line-1&2 tripped on transient faults. 400kV Nellore-SEPL line got tripped on operation of directional earth fault protection.

Recommendations:The PCSC forum requested PGCIL to submit the detailed trip

analysis report for all the three occasions (16:59, 17:01 and 17:03 hrs) to SRLDC and SRPC.

SEPL / PGCIL Yet to be informed. Pending

27-05-14 at 14:26 hrs &

29-05-2014 at 17:01 hrs

22 33/I/8 5 Multiple element tripping and generation loss at 400kV Neyveli TS-2 station

05-06-14 at 19:10 hrs Lighting cable of switchyard gantry tower got broken and fell over 400kV bus-1 resulting into a bus fault on 400kV bus-1 at Neyveli TS2

SRPC:• Due to generating units tripping at NLC, a problem of low voltage conditions develop at Kayathar area leading to wind power withdrawal from the grid. As this withdrawal is having impact on the inter-regional tie-lines, the issue should be resolved as quickly as possible.

NLC informed. NLC informed that all unused lighting cables hanging from various towers were removed by availing LC on Bus and feeders.

All corrective and preventive actions have been taken to ensure non-occurrence of such trippings.

Completed

23 33/I/9 6 Tripping of 400kV Karaikudi-Madurai line

05-06-14 at 20:20 hrs Line tripped at Madurai end only and was holding from Karaikudi end. It was reported in FIR that line distance protection over reached

PGCIL: • EPAC relay mal-operated while charging the Trichy - Karaikudi line, hence the tripping of the line. The file from relay was downloaded and replayed, but it did not trip the relay.

PGCIL informed. EPAC relay mal-operation observed. The relay was replaced by 7SA522 relay subsequently.

Completed

24 33/II/1 7 400kV Hassan-UPCL line-2 19-05-2014 at 16:06 hrs Transient fault had occurred in R-phase and line auto reclosed from Hassan end

• It was noted that distance protection of Main-I sensed R-Y fault and Main-II sensed R-N fault (2 KA current).RecommendationThe PCSC forum requested KPTCL /UPCL to check the both the

relays and CTs for variation in sensing and operation.

UPCL / PGCIL / KPTCL

Yet to be informed. PGCIL informed that no problem at their end

Pending (UPCL / KPTCL )

18

21

PGCIL

33/I/6 4 Tripping of 765kV Raichur-Sholapur line

Line tripped due to transient faults. Line did not try to auto reclose.

Deliberations:The issue was noted.

PGCIL

33/I/3 1 Tripping of 400kV Jeypore-Gajuwaka line-1&2 and Pole 1&2 at HVDC Back to Back station at Gazuwaka

Line-2 tripped on R-N fault. Line-1 tripped from Gajuwaka end only. HVDC tripped due to loss of East bus voltage.RecommendationsThe PCSC forum recommended PGCIL to submit the following to

SRLDC and SRPC:• DR of Jeypore - Gajuwaka lines tripping on 22.5.2014 and 7.6.2014• Action taken for testing the relay or its replacement.• Complete analysis of the faults and rectification/remedial action taken to avert similar occurrence in the HVDC Back to Back station.

Yet to be informed.

Yet to be informed. Pending

Pending

5

ANNEXURE-III

25 33/II/2 8 400kV Ramagundam-Hyderabad line-4

19-05-2014 at 21:00 hrs Transient fault had occurred in R-phase. Line auto reclosed at Ramagundam and failed to reclose at Hyderabad due to direct trip receive.

• NTPC: no PLCC counter has gone up (incremented) at Ramagundam• PGCIL: DT was received from Ramagundam, and hence the tripping of the line.RecommendationThe PCSC forum requested for joint checking of PLCC system by

NTPC and SRTS I, PGCIL .The report to be sent to PCSC forum at the earliest.

NTPC , PGCIL Yet to be informed. Pending

22-05-14 at 19:32 hrs

23-05-2014 at 16:56 hrs

27 33/II/5 10 400kV VTPS – Malkaram-1 26-05-2014 at 02:14 hrs 400kV VTPS-Malkaram line-1 tripped on a y-Phase to ground fault. Line auto-reclosed at Malkaram end

RecommendationPCSC forum requested SLDC of Andhra Pradesh / Telangana to take

up the issue with the generator ( VTPS) for attending/ correcting the problem.


28 33/II/6 11 400kV Khammam-Mamidipally line-1

26-05-14 at 3:31 hrs Line tripped on a R phase to earth fault . Line did not auto reclose and Y- and B pole of breakers opened 400 ms after opening of R-pole

It was informed that Stage-2 O/V setting is 140 % @ 100 ms. During the process of auto-reclosing, O/V occurred at the dead time and the line tripped.

PGCIL / TSTRANSCO

informed High voltage incident occurred after 300ms of the occurance of fault causing operation of Stage-II O/V relay at 400KV Mamidipally SS of TSTRANSCO. Trip command was extended to Y & B phases instantaneously instead of 100ms due to timer problem. The defective timer has been replaced. [Report Enclosed]

Completed

29 33/II/10 12 400 kV RAMAGUNDAM - WARANGAL

13-06-14 at 16:38 hrs B-phase to ground fault had occurred. Line failed to reclose from Ramagundam end.

NTPC:Main-I distance protection relay sensed single phase fault and Main-II relay (RAZFE-ABB) sensed R-Y (line to line) fault which got priority over single phase fault and the line was given 3-phase tripping.

NTPC , PGCIL , APTRANSCO


30 34/I/3 1 Tripping of HVDC Bhadravati Pole-1&2

09-07-2014 at 3:50 hrs and 5:04 hrs

As reported pole-1&2 tripped due to auxiliary supply failure.

Recommendations: The PCSC forum recommended PGCIL, SRTS-I take up the issue

with WRTS to submit the report as per IEGC guidelines. SRLDC is also requested to send a letter to WRLDC to submit the

reports to SR also. Based on the SRTS/SRLDC correspondences, SRPC would take it

up with WR and PGCIL if the issue is not getting resolved. Complete analysis of the faults and rectification/remedial action

taken to avert similar occurrence in the HVDC Back to Back station shall be submitted.

PGCIL Yet to be informed Pending

KPCLB 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.RecommendationThe PCSC forum requested KPCL to enable the A/R feature at RTPS

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

400kV Hiriyur-BTPS line-233/II/3 926 A/R at BTPS end will be danbled during November 2014 End and needs LC

Pending

6

ANNEXURE-III

31 34/I/6 2 400/220 kV ICT-1 & 2 at MUNIRABAD

16-07-2014 at 2:31 hrs As reported directional over current relay of ICT’s operated due to snapping of line jumper in 220kV Lingapur line.

Recommendations: Bus bar protection shall be provided by asset owner ( i.e KPTCL) .

Settings for main distance protection & Overcurrent protection shall be examined and reviewed. Time synchronization of the Substation shall be ensured. Correct DR shall be submitted to the SRLDC for trip analysis.

KPTCL Management approval is obtained for taking up the work of providing bus bar protection to 220kV buses at Guddadahally (Munirabad) Sub Station along with replacement of 3 core/age old CTs of 220kV bays belong to KPTCL. Finalization of scheme/specification is under process.

Pending

32 34/I/7 3 HVDC BHADRAVATHI POLE 2

18-07-2014 at 20:10 hrs As reported pole-2 tripped due on 5th harmonic alarm.

Recommendation : Complete analysis of the faults and rectification/remedial action

taken to avert similar occurrence in the HVDC Back to Back station shall be submitted. The PCSC forum recommended PGCIL, SRTS-I take up the issue

with WRTS to submit the report as per IEGC guidelines. SRLDC is also requested to send a letter to WRLDC to submit the reports to SR also. Based on the SRTS/SRLDC correspondences, SRPC would take it up with WR and PGCIL if the issue is not getting resolved.


33 34/II/2 4 400kV Kurnool-Srisailam line 21-06-2014 at 7:55 Recommendation : Relays with DR feature shall be installed within two months time;

since there is a bus coupler at Srisailam, it could be done in a phased manner.

APTRANSCO One Number of Numerical Distance relay was allotted to replace the static relay on Srisailam feeder at Kurnool as a remedy.Relay yet to b commissioned.

APTRANSCO informed that the isue was discussed in the 38th PCSC meeting about the remedial measures taken and committee recommended to replace the relay with in 3 to 4 months

Pending

34 34/I/3 5 400kv Kaiga-Guttur line -2 22-06-2014 at 3:10 D.R/ E.L of Guttur station not furnished

Recommendation :

KPTCL is requested to wire final trip relay contact to DR.

KPTCL Yet to be informed Pending

35 34/I/5 6 400kV Srisailam-Mamidapalli line-2

10-07-2014 at 23:54 D.R/ E.L of Srisailam station were not furnished.Deliberation:Discussed in S.No. 4


36 34/I/7 7 400kV Kalpaka-Vemagiri line-2

12-07-2014 at 02:50 Vemagiri end D.R/E.L not furnished. APTRANSCO APTRANSCO informed that EL was furnished.Extraction of D.R from REL 316 was not possible. The same is informed to the company service personnel.

Completed

37 34/III/1 8 400kV Raichur-BTPS line 26-06-2014 at 1:25 hrs 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

Pending

7

ANNEXURE-III

38 34/III/3 9 400kV Vallur-Kalivandapattu line-1

10-07-2014 at 19:56 hrs& 20:21 hrs

Fault in B-phase. Line did not auto reclose.

PGCIL: • At 19:56 hrs it was 2nd fault within a short time.• At 20:21 hrs D/T was received and while charging it tripped.

PGCIL informed At 19:56hrs, the occurrence of fault is during reclaim time and hence, AR lock out operated. And at 20:21hrs the fault was persisting during energisation and hence, it did not auto reclose.

completed

39 34/IV/a 10 UPCL agenda regarding tripping of Hassan – UPCL – 2 line ( tripped 12 times )

Jul-14 Recommendation :

Constituents were suggested to follow Patrolling Guidelines finalized for SR. The guidelines had been informed to Hon’ble Commission . The Guidelines were available on SRPC website.


40 35/I/2 1 220 kV KAIGA – KODASALLY an 220kV Kodasalli -Nagjheri line

19-07-2014 at 12:22 hrs 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.

Pending

41 35/I/5 2 400kV KTPS-Khammam line-1&2, KTPS unit-11 tripped

31-07-2014 at 20:31 hrs CT blast at KTPS SRPC:TSGENCO /PGCIL was requested to correct the Time drift in the

KTPS-Khammam corridor at the earliest and the same may be informed to the SRPC Secretariat on or before the next PCSC meeting.

TSGENCO / PGCIL


42 35/I/8 3 400/220kV ICT-2 at Vijayawada

09-08-2014 at 13:53 hrs ICT tripped due to downstream fault in 220kV system.

Recommendation :• SRTS- I (PGCIL) and APTRANSCO were requested to check up the DT signal settings (both at initiation and reception points) in their respective substations and cross check their system. The details shall be sent to SRPC Secretariat on or before the next PCSC meeting.

APTRANSCO / PGCIL

APTRANCO informed that they had checked all settings and wirings. The protection settings at APTRANSCO end are in order.

Pending (PGCIL)

43 35/II/1 4 400 kV KURNOOL - SRISAILAM

29-07-2014 at 20:50hrs Y-phase to earth fault. Line did not auto reclose

• Old static relay would be replaced by numerical relay.• APTRANSCO informed the forum that the static relay would be replaced with the Numerical realy with in 3 month’s time.

APTRANSCO APTRANSCO informed that one number of Numerical distance relay was allotted to replace the static relay on Srisailam feeder at Kurnool Substation as an inteirm measure.Rely yet to be commissioned.

Discussed in the 38th PCSC meeting about the remedial measures taken and committee recommended to replace the relay with in 3 to 4 months

Pending

8

ANNEXURE-III

44 36/I/3 1 400 kV Khammam-Kalpakka line- 1

23-08-2014 at 18:24 hrs Line tripped at Khammam end only on operation of distance Protection and was holding from Kalpaka end. The reason for operation of distance protection needs to be furnished

Recommendations:

a. Indication of the SOTF operation and Open jumper detection should be furnished. b. PGCIL was recommended to check the fuse failure logic and the relay settings at their end.c. Distance protection scheme should be investigated.PGCIL was requested to refer the case to OEM for possible remedy.

PGCIL/ APTRANSCO

APTRANSCO informed that the Line is inservice from Kalpaka. There is no issue from APTRASNCO

Pending (PGCIL)

45 36/I/5 2 ICT -1 & 2 at Guttur Substation

26-08-2014 at 13:44 hrs ICT’s tripped on operation of Earth fault relay. Triggering incident was failure of Jumper in 220kV Guttur-Neelagunda line.

Recommendations:

a. Protection System Analysis Group (PSAG-8) was held on 25 & 26.09.2014 at Guttur (400 KV, KPTCL SS ) to discuss the frequent tripping of 400KV Kaiga-Guttur lines on account of over-voltage and transient faults .The Minutes of the PSAG-8 Meeting is enclosed herewith as Annexure – V.b. KPTCL was requested to send the steps/action taken to implement the recommendations of the PSAG-8 meeting held at Guttur on 25&26.09.2014 to the PCSC.

KPTCL Pointwise compliance on PSAG-8 MOM is furnished to SRPC

partially completed and partly Pending

46 36/I/6 3 765kV Raichur-Kurnool 27-08-2015 at 10:15 hrs line tripped at Kurnool end only and was holding from Raichur end.Distance protection Zone-4 got operated while replacing VT fuse and tripped the breaker at Kurnool end.

Recommendations:The PCSC forum requested PGCIL, SRTS-I to check / review the CVT fuse alarm logic


47 36/I/7 4 765kV Raichur-Kurnool 30-08-2014 at 17:52 hrs Relay Mal-operation at Raichur End Recommendations:

The PCSC forum requested PGCIL, SRTS I to check / review the CVT fuse alarm logic.


48 36/I/8 5 Multiple Tripping at 400 kV Guttur station

12-09-2014 at 12:22 hrs 400kV Kaiga-I, Hiryur-I, Narendra-I & ICT-I tripped at Guttur station due to operation of bus bar protection of 400kV Bus-1 at Guttur. It was reported that the LBB protection acted due to wrong configuration of distance relay

Recommendations:

a. Protection System Analysis Group (PSAG-8) was held on 25& 26.09.2014 at Guttur (400 KV, KPTCL SS ) to discuss the frequent tripping of 400KV Kaiga-Guttur lines on account of over-voltage and transient faults .The Minutes of the PSAG-8 Meeting is enclosed herewith as Annexure – V.b. KPTCL was requested to steps/action taken to implement the recommendations of the PSAG-8 meeting held at Guttur on 25&26.09.2014 to the PCSC.

KPTCL Pointwise compliance on PSAG-8 MOM is furnished to SRPC

partly completed and partly Pending

49 36/I/9 6 220kV Srisailam right bank station

03-09-2014 at 10:41 hrs It was reported that trip wire to circuit breaker of 220kV Dindi-2 was open which resulted in operation of LBB protection and tripping of all elements connected to 220kV Bus-2.

Deliberation & Recommendation: a. The issue was discussed in the Protection System Analysis Group (PSAG-9) meeting held at Srisailam Right Bank Power House (SRBPH) on 14& 15.10.2014 .b. APGENCO was requested to inform the steps /action taken to implement the PSAG-9 meeting recommendations during the next PCSC.

APGENCO Pointwise compliance on PSAG-9 MOM is furnished to SRPC


50 36/I/10 7 220kV Srisailam right bank station

03-09-2014 at 16:09 Mal-operation of LBB relay which resulted in tripping of all elements connected to 220kV Bus-1

Deliberation & Recommendation:

a. The issue was discussed in the Protection System Analysis Group (PSAG-9) held at Srisailam Right Bank Power House (SRBPH) on 14& 15.10.2014 .b. APGENCO was requested to inform the steps /action taken to implement the PSAG-9 meeting recommendations during the next PCSC.

APGENCO Pointwise compliance on PSAG-9 MOM is furnished to SRPC


9

ANNEXURE-III

51 36/II/1 8 400kV Munirabad - Guttur 17-08-2014 at 4:05 hrs R-phase to earth fault. Line did not auto reclose at Munirabad end

PGCIL: Problem could be at line CB side.SRLDC: A/R scheme needs checking.

KPTCL / PGCIL Yet to be informed Pending

52 36/II/2 9 400kV Madurai-Costal Energy 21-08-2014 at 14:50 B-phase to earth fault. Line did not auto reclose at Coastal Energy end.

SRLDC:There was an earth fault on B-phase and subsequently A/R scheme has been rectified.

TANTRANSCO / Coastal Energy

Yet to be informed Pending (Coastal Energy / TANTRANSCO(SLDC))

53 36/II/3 10 400kV JSW-Guttur line 21-08-2014 at 23:32 hrs R-phase to earth fault. Line did not auto reclose

• Decapping of insulator resulted in persisting fault that led to the tripping of the line.

JSW / KPTCL Yet to be informed Pending

54 36/II/5 11 400kV Ramagundam-Chandrapur line – 1

25-08-2014 at 17:52hrs Line tripped on B-phase to earth fault. As per FIR of chandrapur station, line did not auto reclose as auto reclose is kept out of service.

Recommendation:PGCIL to take up the issue with OEM in this regard.


03-09-2014 at 12:46hrs

04-09-2014 at 12:52 hrs

56 36/II/8 13 400kV Raichur-Munirabad line 07-09-2014 at 00:03hrs B-phase to earth fault had occurred in line. Line auto reclosed at Munirabad end and failed to reclose at Raichur end

KPTCL: PD (pole discrepancy) time delay would be changed.

PGCIL / KPTCL Yet to be informed Pending

57 36/II/9 14 400kV Arasur-Mettur Line I 29-09-2014 at 21:10 hrs Recommendation:Mettur S/s to Enable A/R Scheme.

TANTRANSCO During the 38th PCSC meeting ,TANTRANSCO informed that the Auto Reclosing facility would be enabled within 15 days.

Pending

36/II/7 12 400kV VTPS-Malkaram line 55 TSTRANSCO informed that from their end DR & EL reports were uploaded with in 24 hours from Malkraram end.

R-phase to earth fault. line did not auto reclose

APGENCO: • DR and EL were not uploaded (at SRLDC website) for this event, as the user login details were not known. The same would be obtained from SRLDC

TSTRANSCO / APGENCO

Pending (APGENCO)

10

ANNEXURE-III

58 37/I/1 1 Tripping of 400/220kV ICT-1 & ICT-2 at 400kV Warangal substation

18-09-2014 at 21:01 hrs ICT’s tripped due to operation of Directional Earth Fault relays on 400 KV side of ICT 1 &2. It was informed that fault had occurred in downstream 220kV system. From D.R of ICT’s fault ampere of 2kA and 2.7kA in R phase was observed for ICT-1&2 respectively. The tripping need further analysis as the fault current was not high to operate the High set of earth fault relay and there was no delayed clearance of fault in 220kV system.

Recommendations:PGCIL is requested to send trip analysis indicating the cause of high set operation despite not very high fault current.


59 37/I/2 2 Tripping of 400kV Bus-1 and 400kV Ramagundam-Nagarjunasagar line

19-09-2014 at 12:44 hrs LBB protection of 400kV Ramagundam-N’sagar line had mal-operated due to spurious initiation from 86 trip relay which caused tripping of 400kV Ramagundam-N’sagar line and direct trip to remote end. Along with this LBB

Recommendations:NTPC is requested to explore the possibility of including re-trip feature in the LBB relay before actual LBB initiation.


60 37/I/3 3 Tripping of 400kV Raichur-Mahboobnagar line

20-09-2014 at 22:34 hrs line tripped at Raichur end only due to operation of carrier lock out relay

Recommendations:KPCL is requested to expedite the process of installing adequate DC batteries for PLCC system.

KPCL Yet to be informed Pending

61 37/I/4 4 765/400 kV ICT-3 at NPS 22-09-2014 at 7:48 hrs FIR, D.R, E.L not submitted. As per verbal information L.A failure had caused tripping of ICT

Recommendations:a. As despite normal voltage at 400 kV bus, new LA and bus reactors in service, the failure of LA shall be investigated by PGCIL and a report shall be sent to the PCSC forum.b. Efforts shall be made to retrieve the DR data pertaining to the differential operation and the retrieved data shall be sent to PCSC forum. c. Equipment failure report for 400 kV LA shall be sent to SETD division of CEA, New Delhi.

PGCIL / NPS Yet to be informed Pending

62 37/I/5 5 220kV Ambewadi-Ponda line 25-09-2014 at 12:54 hrs As per FIR line was hand tripped due to 220/110kV Bus dead. Reason for bus de-energization may be furnished to PSC

Recommendations:a. A trip analysis report shall be with the corrective actions for the following issues shall be sent to PCSC forum.b. Measures for preventing Ambewadi – Nagjheri line -1 opening in case of fault on the Ambewadi – Nagjheri line -2 and vice versa.


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ANNEXURE-III

63 37/I/6 6 Tripping of 400KV Hassan-UPCL line-2

25-09-2014 at 16:16 hrs High resistance fault as the fault ampere was very less i.e., 0.6kA at Hassan end and nearly 0.9kA at UPCL end. Back up earth fault protection had operated at Hassan. At UPCL end the high resistance fault got converted into a R ph-B-ph fault which resulted in operation of distance protection Zone-1. The reason for non-picking up of Back up earth fault at UPCL needs investigation.

Recommendations:a. At UPCL end, unused zones of distance protection (probably zone 5 to 8) shall be disabled.b. At UPCL end, time synchronization between main-1 and main-2 relays shall be ensured.c. UPCL shall ensure time synchronization with Hassan substation.d. Reasons for non operation of back up protection at UPCL for high resistance fault is to be submitted.e. Reasons for not sending DT to UPCL by Hassan end is to be submitted.f. Settings of UPCL are to be reviewed and informed to PCSC forum.

UPCL / KPTCL / PGCIL

Yet to be informed PGCIL informed that requirement of sending DT during DEF protection is not as per basic protection philosophy.

Pending (UPCL/ KPTCL)

64 37/I/7 7 Tripping of 400/220 kV ICT-1 AT BTPS

27-09-2014 at 16:22hrs FIR, D.R, E.L not submitted. As per verbal information due to problem in 220kVside

Recommendations:KPCL is requested to collect DL, EL and trip analysis and submit to PCSC forum.


65 37/I/9 9 Tripping of 400/220kV ICT-1&2 at UPCL

04-10-2014 at 12:16 hrs ICT-1&2 tripped during transient fault in R-phase in 400kV Hassan-UPCL line-1

Recommendations:To avoid tripping of ICTs for line fault, UPCL is requested to review the settings of ICT’s SEF relay and consider IDMT setting instead of existing Definite Time setting.

UPCL Yet to be informed Pending

37/I/10 10 Tripping of 400kV NPS-MEPL line

08-10-2014 at 7:04 hrs Line tripped due to DT receive from MEPL

Recommendations:a. The exact reason for receipt of DT signal at NPS end from MEPL end has to be found out and corrective measures need to be taken up by both MEPL and NPS to avoid its recurrence.b. The forum decided to invite MEPL and SEPL whenever there is a tripping involving their power stations.

MEPL / PGCIL Yet to be informed Pending

66 37/I/11 11 Tripping of 400 kV NPS - TPCIL 2

08-10-2014 at 7:04 hrs Line tripped at NPS end only. As per FIR, R-B phase fault had occurred in 400kV NPS-TPCIL line-1

Recommendations:a. At NPS end, corrective measures shall be taken to avoid tripping of line-2 CB for the fault on line-1 and vice versa.b. Both NPS and TPCL shall ensure time synchronization with each other.c. Status of recommendations of PSAG-1 meeting held at NPS (on 24th July, 2013 ) shall be submitted.

TPCIL / PGCIL Yet to be informed Pending

67 37/I/13 12 Tripping of 400kV Raichur-Munirabad line

09-10-2014 at 14:03 hrs line tripped due to operation of carrier lock out relay

Recommendations:KPCL is requested to expedite the process of installing adequate DC batteries for PLCC system.


68 37/II/3 13 400kV Mettur-Arasur line-1 29-09-2014 at 21:10 hrs line tripped due to Y-Phase to earth fault. Line did not auto reclose as Auto reclose scheme is kept in non-auto mode.

· A/R is not in service. TANTRANSCO Yet to be informed Pending

69 37/II/5 14 400 kV NEYVELI TS 2 (EXP) - PUGALUR

05-10-2014 at 21:47hrs Y-phase to earth fault had occurred in line. Line did not auto reclose. DT was received from Neyveli TS2(EXP) end

Have to submit remedial measures NLC informed NLC informed that ,It is programmed to test the Main-2 relay within 31-12-14, for further processing.

Pending

70 37/III/2 15 400kV Srisailam-Satenapalli-2 19-09-2014 at 20:53 hrs · D.R of Srisailam end not submitted TSGENCO Yet to be informed Pending

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ANNEXURE-III

Minutes of the 39th Protection Coordination Sub Committee meeting · PDF file ·...

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