Kar · 2020. 11. 23. · Protection Coordination Sub-Committee(PCSC) of SRPC to be held on 2nd...

Additional Agenda for 93rd Meeting of PCSC scheduled to be held on2nd December 2020 (online through WebEx) Page1/4

Southern Regional Power Committee Bengaluru

Additional Agenda for 93rdmeeting of

Protection Coordination Sub-Committee(PCSC) of SRPC

to be held on 2nd December, 2020 online through WebEx

1. Frequent tripping of 400kV KKNPP – Tirunelveli line-2

a. A special meeting was held on 4thNovember 2020 to discuss the frequent tripping of

400kV KKNPP – Tirunelveli line-2 and prolonged outage of 400kV KKNPP – Tirunelveli

line-1 (since July 2020). The instances of tripping are given below:

Sl.

No.

Event Description Elements tripped

1 Multiple tripping in 400kV Kudankulam SS

at 05:48 Hr. on 26-07-2020.

i. 400kV Kudankulam - Tirunelveli line-2

ii. 400kV Kudankulam - Tuticorin PS-2

2 Multiple Tripping in 230kV/110kV TTN Auto

SS of TANTRANSCO and 400kV/230kV

Kudankulam Nuclear Power Plant (KKNPP)

of NPCIL at 22:10Hr. on 08-10-2020.

i. 230kV TTN Auto- TTPS line-1 and 2.

ii. 230kV TTN Auto- Kayathar line-1

iii. 230kV/110kV Transformer-1 and 2 at TTN

Auto SS

iv. 400kV KKNPP - Tirunelveli line-2

v. 230kV KKNPP - TTPS

vi. 230kV KKNPP - SR Pudur

3 Multiple Tripping in 230kV/110kV TTPS of

TANGEDCO and 400kV/230kV KKNPP of

NPCIL at 17:38 Hr. on 30-10-2020.

i. 230kV TTN Auto- Kayathar line-1

ii. 400kV KKNPP - Tirunelveli line-2

iii. 230kV KKNPP - TTPS

4 Multiple Trippingin 400kV/230kV

Kudankulam Nuclear Power Plant(KKNPP)

of NPCIL at 17:58 Hr. on 02-11-2020.

i. 400kV KKNPP - Tirunelveli line-2

ii. 230kV KKNPP - TTPS

iii. 230kV KKNPP - SR Pudur

b. NPCIL- KKNPP and TANTRANSCO may update on the status of action taken on the

recommendations during the special meeting.

2. Confirmation Status of insulator replacement in following lines:

i. 400kV Hassan – Nelamangala

ii. 400kV Nelamangala – Talaguppa.

a. During September - October 2019, as per information from KPTCL, the above lines

were kept in non-auto mode due to insulator replacement works. However, it has

been observed that during the recent trippings of 400kV Nelamangala – Talaguppa

lines, auto reclose function in the line is in disabled condition.

b. KPTCL may update status.


3. Review of Distribution of Loads and Signal Paths of Raichur – Sholapur SPS, Talcher-

Kolar SPS, and Kundankulam (Unit-I & II) SPS – Status Update

a. A meeting was held on 10th September 2020 to finalise SPS DS matrix for Raichur –

Sholapur SPS, Talcher-Kolar SPS and Kudankulam (Unit-I & II) SPS and the finalized

matrix was communicated to all constituents for taking up any pending works.

b. During the recent HVDC Talcher-Kolar Pole trippings, it has been observed that signal

has not got extended to some of the load points in Tamil Nadu, Andhra Pradesh.

PGCIL / constituents shall update status on the pending works.

c. Further, during tripping of HVDC Talcher-Kolar Pole-1 SPS Trip signal-1 had operated

on 23rdOctober 2020 at 21:33 Hr. However,the trip signal was not received at

Andhra Pradesh.There was no load relief in Andhra Pradesh.

d. Andhra Pradesh and PGCIL may apprise.

4. Tripping Frequent tripping of 220kV Ambewadi – Ponda(Xeldem) line-1

a. There had been frequent tripping of 220kV Ambewadi – Xeldem line on single line to

ground fault. Instances of tripping during August to October 2020 is given below:

S.NO. ELEMENT NAME TRIPPING

DATE TRIPPING

TIME OWNER (SEND)

OWNER (REND)

REMARKS

1 220kV Ambewadi - Xeldem 01-Aug-20 17:47 KPTCL GOA R-N Fault

2 220kV Ambewadi - Xeldem 04-Aug-20 14:36 KPTCL GOA R-N Fault

3 220kV Ambewadi - Xeldem 26-Aug-20 13:53 KPTCL GOA Y-B Fault



6 220kV Ambewadi - Xeldem 31-Aug-20 14:15 KPTCL GOA B-N Fault

7 220kV Ambewadi - Xeldem 05-Sep-20 14:01 KPTCL GOA B-N fault





12 220kV Ambewadi - Xeldem 01-Oct-20 08:30 KPTCL GOA B-N fault


14 220kV Ambewadi - Xeldem 19-Oct-20 23:53 KPTCL GOA Y-N Fault




18 220kV Ambewadi - Xeldem 26-Oct-20 20:07 KPTCL GOA

Line did not trip at Ambewadi

end.

19 220kV Ambewadi - Xeldem 27-Oct-20 13:10 KPTCL GOA Y-B Fault



b. KPTCL may apprise.


5. Frequent tripping of 220kV Asupaka-Lower Sileru line

a. The issue of frequent tripping of 220kV Asupaka – Lower Sileru line was discussed in

PCSC-92 held on 29th September 2020. It was informed in the meeting that frequent

faults were occurring in the line due to vegetation along the length of the line.

b. It was also informed that the auto reclose in the line is in disabled condition.

TSTRANSCO had informed that auto reclosure at Asupaka end was disabled since AR

was not in service at Lower Sileru end. APGENCO had informed that Auto Reclosure

at Lower Sileru end would be enabled within a week’s time.

c. Instances of tripping of the line during August – October 2020 are given below:

S.NO. ELEMENT NAME TRIPPING

DATE TRIPPING

TIME OWNER (SEND)

OWNER (REND)

REMARKS

1 220kV Asupaka – Lower Sileru

01-Aug-20 11:01 TSTRANSCO APGENCO B-N Fault


18-Aug-20 19:19 TSTRANSCO APGENCO Y-N Fault


22-Aug-20 13:01 TSTRANSCO APGENCO Y-N Fault


29-Aug-20 10:33 TSTRANSCO APGENCO R-N Fault


01-Sep-20 10:48 TSTRANSCO APGENCO B-N Fault


05-Sep-20 10:41 TSTRANSCO APGENCO Y-N Fault




08-Sep-20 14:35 TSTRANSCO APGENCO R-N Fault






24-Sep-20 13:32 TSTRANSCO APGENCO R-N Fault




02-Oct-20 12:07 TSTRANSCO APGENCO Y-N Fault


03-Oct-20 20:53 TSTRANSCO APGENCO R-N Fault


08-Oct-20 10:10 TSTRANSCO APGENCO B-N Fault








13-Oct-20 10:15 TSTRANSCO APGENCO B-N Fault
















d. APGENCO vide email dated 19.11.2020 had informed that for the subject line A/R at Lower Sileru end has been enabled since 02.11.2020

e. TSTRANSCO / APGENCO may update status of implementation of the decision taken in PCSC-92 meeting.

6. Review of Protection audit recommendation – Power swing block

a. TANTRANSCO, vide email dated 22.09.2020, had informed that, the following recommendation regarding power swing was made during the Protection audit of 400kV Manali and 230kV NCTPS SS conducted in 2019:

i. Zone 1 Trip, Higher Zones block for a delay of unblocking time delay (2sec) and then trip.

ii. Block all zones with out-of-step tripping enabled at electrical zero locations by carrying out required system studies.

b. TANTRANSCO had adopted block all zones with unblocking time of 2 sec. If any line fault is detected, unblock immediately and initiate tripping. TANTRANSCO stated that with this philosophy no unwarranted tripping have been encountered.

c. They also stated that with reference to audit recommendation and to trip the breaker in Zone-1 during recoverable swing condition, the probability of damage to breaker is high (as stated in the Ramakrishna Committee recommendation). The electrical zero locations of grid during power swing may vary according to the grid conditions. (major contribution is from RE source).

d. TANTRANSCO has requested to drop the above protection audit point and to continue with their existing philosophy of “block all zones with unblocking time of 2 sec. If any line fault is detected, unblock immediately and initiate tripping”.

e. The issue may be discussed in meeting.

*****

AA-93(coverpage)Agenda PCSC93_addressAA-93_Final

Date post:	19-Feb-2021
Category:	Documents
Upload:	others
View:	0 times
Download:	0 times

Kar · 2020. 11. 23. · Protection Coordination Sub-Committee(PCSC) of SRPC to be held on 2nd...

Documents