Minutes - ERPC

Minutes of

43rd PCC meeting

Date: 03.06.2016 Eastern Regional Power Committee

14, Golf Club Road, Tollygunge Kolkata: 700 033

EASTERN REGIONAL POWER COMMITTEE

MINUTES OF 43RD PROTECTION SUB-COMMITTEE MEETING HELD AT ERPC,

KOLKATA ON 23.05.2016 (MONDAY) AT 11:00 HOURS

List of participants is enclosed at Annexure-A.

PART – A

ITEM NO. A.1: Confirmation of minutes of 42nd Protection sub-Committee Meeting held on 27th April, 2016 at ERPC, Kolkata.

The minutes of 42nd Protection Sub-Committee meeting held on 27.04.16 circulated vide letter dated 10.05.16. Members may confirm the minutes of 42nd PCC meeting. Deliberation in the meeting DVC vide mail dated 19th May 2016 requested for correction in Item No. B.3 and B.8 In the deliberation of Iitem No.B3 it was mentioned that “DVC informed that GT CB has been tested found satisfactory.” The same is now modified as: “DVC informed that the CB(GT) was thoroughly tested and rectifying measures taken till found satisfactory before putting back into service.” In Item No. B.8, the Sl No. 3 of other single line tripping is modified as: “400 KV RTPS-ANDAL-II tripped at 15:16hrs on 09.03.16 and from ANDAL end B-N, Zone 2 carrier received”. Members confirmed the minutes of 42nd PCC meeting with above amendments.

PART – B

ANALYSIS & DISCUSSION ON GRID INCIDENCES WHICH OCCURRED IN CTU/STU SYSTEMS DURING APRIL, 2016. Item No B.1. Disturbance in Odisha System

B.1.1: Total power failure at 400/220kV Mendhasal S/s of OPTCL System on 12-04-

16 at 14:04 hrs. At 12:40 hrs, all the 400 kV feeders emanating from the Mendhasal S/s were tripped from remote end due to fault in idle charged portion of 220 kV Mendhasal – Bindansi line-II. All the lines were restored by 13:16 hrs. Thereafter, at 14:04 hrs, during charging of 220 kV Nayagarh-Mendhasal line 400/220 kV ICT I & II at Mendhasal S/s tripped on overloading.

Relay indications are as follows:

Time Name Mendhasal end Remote end

12:40 hrs

400 kV Mendhasal – Meramundali S/C

Did not Trip O/C, R Phase at Meramundali

400 kV Mendhasal – Baripada S/C

Did not Trip Z-II, 381.5 km from Baripada

400 kV Mendhasal – New Duburi S/C

Did not Trip Z-III, 486 km from New Duburi

14:04 hrs

400/220 kV ICT I & II at Mendhasal

O/C protection at both end

Analysis of PMU plots:

• At 12:40:30 hrs 4 kV voltage dip has been observed in B and Y Ph voltage at Talcher PMU data. Fault clearance time was 600 ms. approximately

• At 14:04 hrs no fault was observed in PMU data OPTCL and Powergrid may explain the following:

• Reason for not clearing the fault in idle charged portion of 220 kV Mendhasal- Bidansi line II from 220 kV Mendhasal end

• The fault in 220kV network should be cleared from 315 MVA, 400/220kV ICTs at Mendhasal. OPTCL may explain the non-clearance of fault by both 315 MVA ICTs at Mendhasal.

• Powergrid may explain the zone-2 tripping of 400 kV Mendasal – Baripada from Baripada end as it is more than 1.2 times of the line length (276 km).

• OPTCL may investigate the reason for simultaneous tripping of both 315 MVA ICTs on O/C protection from the both sides at 14:04 hrs.

Minutes of 43rd PCC meeting 2

• OPTCL may furnish the duration of disturbance and amount of energy un-served during

these incidents. Deliberation in the meeting OPTCL explained that

• There was a fault in 220 kV Mendhasal – Bindansi line-II (idle charged from Mendhasal) which was not cleared from Mendhasal end because of problem in Auxiliary relay circuit.

• The trip coil supervision unit has given an alarm for the same however, it was overlooked by the operator as the line was under idle charged condition.

• LBB protection at 220 kV Mendhasal was defective and kept in out of service. • The 400/220 kV ICTs also failed to clear the fault. • It was explained that the fault current was probably less than the relay pick up current. • So ultimately the 400kV lines of Mendhasal S/s tripped from remote end and cleared the

fault. • ICTs at Mendashal were not tripped and the exact reasons could not be ascertain as

OPTCL missed to download the respective data. Powergrid informed that

• 400 kV Mendasal – Baripada S/c line was tripped from Powergrid end on zone 2 distance protection and 3.26 kA fault current was observed at Baripada end.

• It was informed that line configuration between Mendasal, Baripada was 400kV double circuit line and zone 2 setting was at 150%. Recently one line has been LILO at 400kV Pandiabil S/s but the zone 2 setting at Baripada was not reviewed.

• This resulted in over reaching of zone 2 at 400kV Baripada. • Powergrid confirmed that the zone 2 reach setting has been revised to 120%.

Regarding tripping of 315 MVA, 400/220kV ICTs on over curent protection from the both sides at 14:04 hrs, OPTCL explained that

• At 13:15hrs, 220 kV Meramundali-Bhanjanagar-II was tripped from both ends on transient E/F. 220 kV Meramundali-Bhanjanagar-I was under shutdown.

• After tripping of 220 kV Meramundali-Bhanjanagar-II the power flow of 315 MVA, 400/220kV ICTs at Mendhasal was gradually increased and tripped on over load.

After detailed deliberation, PCC advised OPTCL to rectify the bus bar and LBB protection at 400kV Mendhasal S/s at the earliest and bring into service.

B.1.2: Disturbance at 400/220kV Mendhasal S/s of OPTCL System on 16-04-16 at 09:55 hrs.

At 09:55hrs, 220 kV Meramundali – Bhanjanagar line-II tripped from both ends on B-N fault. At the same time, 315MVA, 400/220 kV ICT I & II at Mendhasal also tripped on O/C protection at 400 kV side. Prior to the tripping, power flow through 220 kV Meramundali – Bhanjanagar line-II was 153 MW from Meramundali to Bhanjanagar. The power flow through each ICT was 250 MVA before the tripping of 220 kV Meramundali-Bhanjanagar-II. As per ERLDC SCADA data, 220 kV bus at Mendhasal and Bhanjanagar were not dead and power was available from Upper Kolab and Indravati HEP through 220 kV Bhanjanagar - Theruvali and 220 kV Mendhasal-Nayagarh-Bhanjanagar line. The power flow was reversed after the disturbance.


Due to dip in voltage, 132 kV Chandaka-Ransingpur line, 132 kV Chandaka-Nimapara Ckt and some 33 kV feeders at Chandaka were hand tripped at Chandaka resulting and there was 140 MW load loss.


Time Name Local end Remote end

09:55 hrs

220 kV Meramundali Bhanjanagar II

At Meramundali

B-N, F/D-114 km

At Bhanjanagar

B-N, Z-I, F/D =39.8 kM

400/220 kV ICT I & II at Mendhasal

O/C relay and LBB operation at 400 kV side

Analysis of PMU plots: No fault was observed in Talcher PMU data OPTCL may explain the following:

• Tripping of 315 MVA ICT I & II at Mendhasal S/s. Deliberation in the meeting OPTCL explained that

• There was a transient B-N fault in 220 kV Meramundali – Bhanjanagar line-II and the line tripped from both ends to clear the fault.

• As a result, the power flow in 315 MVA, 400/220kV ICTs at Mendhasal increased to 90% of the full load.

• After the incidence of 12.04.16, they have implemented a over load alarm for both 315 MVA, 400/220kV ICTs at 90% of the full load. But the logic was inadvertently initiating LBB protection for both the ICTs.

• OPTCL confirmed that the logic has been removed on 6th May 2016 and they will install separate relay for over load alarm within a month.

PCC enquired that the fault was not identified in Talcher PMU plot.


OPTCL explained that the fault transient and fault current was very low (1.7kA approx).

B.1.3: Total power failure at 400/220kV Mendhasal S/s of OPTCL System on 26-04-16 at 14:48 hrs.

As per information received from OPTCL at 14:47 hrs, 400/220kV 315 MVA ICT-I at Mendhasal S/s tripped on actuation of overcurrent protection. This resulted in tripping of other 315 MVA ICT-II at Mendhasal due to overloading. It was informed that the Main CB of 400kV Meramundali- Mendhasal S/c at Mendhasal was already under shutdown and the line was charged through the Tie CB of 400/220kV 315 MVA ICT-I. Thus after tripping of Main CB of 315 MVA ICT-I at Mendhasal on overcurrent, 400kV Meramundali- Mendhasal S/c also tripped from 400kV Mendhasal S/s. Due to tripping of both the 315 MVA ICTs at Mendhasal approx. 400 MW load loss had occurred in Chandaka, Bhubaneswar and its surrounded area. Relay indications are as follows:


14:47 hrs

400/220kV , 315 MVA ICT-I & II at Mendhasal Tripped on overcurrent

400kV Meramundali- Mendhasal s/c

At Mendhasal Tripped (as it was charged through Tie CB of 315 MVA ICT-I)

At Meramundali Did Not tripped


• From the Talcher PMU plot, approx. 2kV voltage dip has been observed in all the three phase at 14:47:55 hrs.

• Fault clearance time was approx. 340 ms.

Status of Reporting: Tripping reports are yet to be received from OPTCL. OPTCL may explain the tripping of 315 MVA ICT I at Mendhasal S/s. Deliberation in the meeting The 315 MVA, 400/220kV ICTs at Mendhasal tripped on LBB protection at 90 % of full load same as deliberated in Item No. B1.2.

B.1.4: Multiple elements tripping at 400kV Meeramandali of OPTCL system on 30-04-16 at 22:02hrs.

At 22:02 hrs, a Y-N fault was occurred in 400kV Sterlite- Meeramandali ckt-I due to bursting of Y-Ph LA of the line at Meeramandali end. But due to delayed opening of Y-Ph pole of the said line, LBB protection had operated at Meeramandali S/s. All the elements connected to Bus-I & II were tripped. 220kV Meeramandali- Bidanasi S/c and Meeramandali- Duburi-I also tripped on indication of Y-N & B-N relay respectively. Due to tripping of above mentioned elements from Meeramandali s/s, running units of GMR, Sterlite & JSPL tripped due to loss of evacuation paths. Generation loss of approximately 853 MW occurred


at GMR U#3, SEL U # 1 & 4 & JSPL. 120 MW load loss occurred in at Bidanasi due to tripping of 220kV Meeramandali- Bidanasi S/c. Relay indications at 400kV Meramundali end are as follows:

S.No Line / ATR / Unit Outage (hrs:mm)

Relay Indications at 400kV Meramundali end Remarks

1 400 KV Vedanta-i 22:02 Y-N, Z-1, Dist-.1 KM, K96(LBB), L2-34 KA

2 400 KV Vedanta-ii 22:02 K86(M/T), Y-N, O/V UpHe pick up

3 400 KV ANGUL-I 22:02 K96(lbb), y-n, z-I, dist-02 km, l2-5.9 ka

4 400 KV ANGUL-II 22:02 K96(lbb), y-n, z-I, k96(lbb), Uphe pick up

5 400 KV RSTPS 22:02 K96, K86, O/V

6 400 KV ICT-2 22:02 K96, K86, O/V , DEVICE TRIP 220 side; m/t, gr AB I phase trip

7 400 KV ICT-I 22:02 K96, K86, O/V , DEVICE TRIP,O/C PICK-UP, PH-2, L2-2.89 KA

220 side; m/t, gr AB I phase trip

8 400 KV DUBURI-I 22:02 Y-N, L2-2.89 KA, L2-E, DIST: -3.5 KM

9 400 KV DUBURI-II 22:02 K96, K86, Y-N

10 400 KV JSPL-I 22:02 BKR NOT TRIPPED, BUT NOT GET POWER SUPPLY

11 400 KV JSPL-Ii 22:02 K86, Y-N, K96, DIST: -3.1 KM

12 400 KV MENDHASAL 22:02 L2-E, L1:-1.65KA, DIST-27.1 KM,

K86

13 400 KV GMR 22:02 DTT TRIP 3 PHASE, L2-2.3 KA, DIST :-3.1 KM

14 220 KV BIDANASI 22:02 L3-N, DIST: -1.0 KM, Gr ab 1 phasetrip relay , mt

15 220 KV DUBURI-I 22:02 b-n, 60km, z-I, m/t

16 132 KV DHENKANAL 22:02 R ph o/c , mt


Bus arrangement at 400kV Meramundali S/s:

Bus I Bus II Tie-Breaker status

Vedanta-II Angul-I 401-off

Mendhsal-I Duburi-II 402-on (Dubur-II main CB off)

Angul-II Vedanta-I 403-on

Duburi-I Mendhsal-II 404-not in service

JSPL-I RSTPS (KANIHA-i) 405-ON ICT-I FUTURE-6 406- not in service

Future-7 ICT-II 407-ON

GMR JSPL-II 408-ON Analysis of PMU plots:

• From the Talcher PMU plot, approx. 80kV voltage dip has been observed in Y-Ph at 22:02 hrs.

• Fault clearance time was approx. 200 ms. OPTCL may explain the following:

• Tripping of all 400kV elements from Bus-I & II of Meramundali S/s • Tripping of 220kV Meeramandali- Bidanasi S/c and Meeramandali- Duburi line-I from

Meramundali S/s. Deliberation in the meeting OPTCL explained that

• Y-N fault was occurred in 400kV Sterlite- Meeramandali line-I due to bursting of Y-Ph LA of the line at Meeramandali end.


• The fault in 400kV Sterlite- Meeramandali line-I was detected by both ends of the line in

zone 1. Sterlite end successfully cleared the fault in zone 1 but at 400kV Meramundali end there was delay in CB operation and hence the LBB got initiated.

• Prior to the operation of LBB the bus bar protection at 400kV Meramundali S/s operated on actuation of high set as huge fault current (34kA approx) was observed and tripped all the lines connected to bus-II.

• After that huge over voltage was observed at Meramundali Bus-I which tripped the other elements on high voltage.

PCC felt that in-depth analysis is required for such disturbances and advised the following to OPTCL: To analyze the disturbance in detail and submit a comprehensive report along with DR and EL

flags within a week so that it would be further discussed in next PCC meeting. To submit the CB test report of Meramundali end of 400 kV Sterlite- Meramundali line. To place an action plan to reduce such disturbances at 400kV Meramundali S/s with a period of

implementation. To submit an action plan for replacement of CB at Meramundali S/s.

B.1.5: Total power failure at 220kV Rengali Switchyard of OPTCL system on 03-04-

16 at 17:58 hrs. At 17:58 hrs, B-N fault was occurred at Rengali (SY) due to busting of B phase CT of 220 kV Rengali (SY) – Tarkera II line. The 220 kV Rengali (SY) - Tarkera II tripped from both ends to clear the fault. However, at the same time following elements tripped:

• 220 kV Rengali PH – Rengali (SY) (tripped from Rengali PH end) • 220 kV Rengali PG- Rengali (SY) D/C (Rengali SY end) • 220 kV Rengali (SY) – Barkote S/C (both ends) • 400/220 kV ICT I & II at Rengali PG



17:58 hrs

220 kV Rengali (SY) – Tarkera II

At Rengali (SY) B-N, D/P, F/D 7.98 km

At Tarkera Y-B, Z-II, F/D 219.59 km

220 kV Rengali (SY) - Barkote

At Rengali (SY) B-N, D/P

At Barkote O/C, E/F

220 kV Rengali (SY)- At Rengali (SY) At Rengali PH


Rengali PH I & II Did not trip B-N, Z-I 220 kV Rengali (SY) - Rengali PG I

At Rengali (SY) Not tripped

At Rengali P/G Information yet to be received

220 kV Rengali (SY) - Rengali PG II

At Rengali (SY) Back up relay

At Rengali P/G Information yet to be received

400/220 kV ICT I & II at Rengali (PG) Master trip relay operated


• At 17:58:14 hrs 40 kV voltage dip has been observed in R-Ph voltage at Talcher PMU data

• Fault clearance time was 80 ms. approximately • 1.8 kA rise in B Phase has been observed in 400 kV Talcher – Rengali I

OPTCL and Powergrid may explain the following:

• PGCIL and OPTCL may explain the reason for tripping of 220 kV Rengali PH – Rengali (SY), 220 kV Rengali PG- Rengali (SY) D/C, 220 kV Rengali (SY) – Barkote S/C, 400/220 kV ICT I & II at Rengali PG.

• Tripping of 220 kV Rengali (SY) – Rengali PH line I & II from Rengali PH end only on Z-I protection.

• OPTCL may furnish the amount of energy un-served during this disturbance. . Deliberation in the meeting OPTCL and Powergrid updated the relay indications as follows:


17:58 hrs

220 kV Rengali (SY) – Tarkera II

At Rengali (SY) B-N, D/P, F/D 7.98 km

At Tarkera Y-B, Z-II, F/D 219.59 km

220 kV Rengali (SY) - Barkote

At Rengali (SY) B-N, D/P

At Barkote O/C, E/F (high set)

220 kV Rengali (SY)-Rengali PH I & II

At Rengali (SY) Did not trip

At Rengali PH B-N, Z-I

220 kV Rengali (SY) - Rengali PG I


At Rengali P/G Backup directional over current pickup

220 kV Rengali (SY) - Rengali PG II


At Rengali P/G Backup directional over current pickup

400/220 kV ICT I & II at Rengali (PG)

Master trip relay operated (high set over current E/F protection)

OPTCL explained that

• B-N fault was occurred at Rengali (SY) due to busting of B phase CT of 220 kV Rengali (SY) – Tarkera II line.

• 220kV Rengali (SY) end tripped on zone 1 distance protection and Tarkera end tripped on zone 2 distance protection.

• In the mean time, high set over current E/F protection of 220 kV Rengali (SY) - Barkote line at Barkote end was operated and tripped the line.

• OPTCL informed that distance protection at Barkote end was out of service and hence high set over current E/F protection was enabled for 220 kV Rengali (SY) - Barkote line as a temporary measure. The distance relay will be replaced by May, 2016.


• 220 kV Rengali (SY)-Rengali PH line I & II tripped from Rengali PH end as the zone-1 each

setting was over reaching. Powergrid informed that---

• 400/220 kV ICT I & II at Rengali (PG) were tripped on high set over current E/F protection. • 220 kV Rengali (SY) - Rengali PG I & II did not trip because the distance relay did not pick

up the high resistive fault and the line is of very short length. PCC advised the following: OPTCL to replace the distance relay at Barkote end at the earliest. OPTCL and OHPC to review the reach settings of distance relays of 220 kV Rengali (SY)-

Rengali PH line I & II lines. OPTCL, OHPC and Powergrid to explore for implementation of Unit protection with

directional E/F and Over current for short lines adjoining to Rengali i.e. 220 kV Rengali (SY)-Rengali PH line I & II and 220 kV Rengali (SY) - Rengali PG I & II lines.

B.1.6: Total Power failure at 220/132kV Tarkera S/s of OPTCL system on 19-04-16

at 09:16 hrs. At 09:16 hrs, R-N fault occurred at 220kV Tarkera due busting of R phase CT of 220 kV Rourkela – Tarkera – I line. The following lines got tripped on operation of bus bar protection at Tarkera:

• 220 kV Tarkera – Rourkela I & II • 220 kV Tarkera – Budipadar – I & II • 220 kV Tarkera – Barkote • 220 kV Tarkera - Rengali II



09:16 hrs

220 kV Tarkera – Rourkela I

At Tarkera R-N, F/D 1.1 km, Bus bar protection

At Rourkela Z-II, R- phase, O/C

220 kV Tarkera - Barkote

At Tarkera Bus Bar protection, D/P

At Barkote Did not trip

220 kV Tarkera-Rourkela - II

At Tarkera Bus Bar protection, R-N

At Rourkela Did not trip

220 kV Tarkera – Budipadar – I & II

At Tarkera Bus bar protection

At Budipadar Did not trip

220 kV Tarkera - Rengali II


At Rengali E/F

220 kV Tarkera - RSP – I & II Did not trip at either end and RSP units islanded from grid


• At 09:16:03 hrs 13 kV voltage dip has been observed in R-Ph voltage at Ranchi PMU data

• Fault clearance time was 400 ms. approximately OPTCL may explain the following:

• Operation time of the bus bar protection at 220kV Tarkera • Tripping of 220 kV Tarkera - Rengali II from Rengali end on E/F protection


• Non- tripping of 220 kV Tarkera - RSP – I & II lines from Tarkera on Bus-bar protection. • OPTCL may furnish the duration and amount of energy un-served during this disturbance.

Deliberation in the meeting OPTCL updated the relay indications as follows:


09:16 hrs

220 kV Tarkera – Rourkela I

At Tarkera R-N, F/D 1.1 km, Bus bar protection

At Rourkela Z-II, R- phase, O/C

220 kV Tarkera - Barkote

At Tarkera Bus Bar protection, D/P

At Barkote Did not trip

220 kV Tarkera-Rourkela - II

At Tarkera Bus Bar protection, R-N

At Rourkela Did not trip

220 kV Tarkera – Budipadar – I & II


At Budipadar Did not trip

220 kV Tarkera - Rengali II


At Rengali E/F

220 kV Tarkera - RSP – I & II Tripped from Tarkera end on Bus bar protection

OPTCL informed that one bus was in service at 220kV Tarkera S/s. All the elements were tripped from Tarkera end on operation of bus bar protection due to R-N fault at 220kV Tarkera because of R phase CT busting of 220 kV Rourkela – Tarkera – I line. OPTCL informed that 220/132kV ICTs were also tripped from Tarkera S/s on bus bar protection. PCC felt that tripping was in order. PCC advised OPTCL to keep both buses in service at 220kV Tarkera S/s for reliable operation.

B.1.7: Total power interruption in S. Orissa system on 15-04-16 at 12:17 hrs – 12:23 hrs.

At 12:17 hrs, 400KV Indravati - Rengali S/c line tripped on transient SLG (i.e. C-N) fault. Auto reclose operation was successful at Indravati end but unsuccessful at Rengali end. After few millisecond, direct trip has been received from Rengali end due to over voltage at Rengali and the line tripped from Indravati end also. Thereafter, the following elements were tripped:

• 400KV Jeypore-Bolangir line (tripped on high voltage from Jeypore) • 400KV Indravati-Jeypore line (tripped on high voltage from Jeypore) • 220/132kV ATR-I,& II at Jayanagar (tripped on over flux) • 220/132kV ATR-I,& II at Bhanjanagar (tripped on over flux) • Running units #2& 3 of U.Kolab (tripped on over flux) • Running unit #5 of Balimela

The bus voltage at Jeypore became zero and 400KV Jeypore-Gajuwaka D/C line was hand tripped from Gajuwaka end. Thus after tripping of above 400kV lines along with 220/132kV ATRs at Jayanagar & Bhanjanagar, there were no other path left to feed the load at South Orissa system mainly at Theruvali, Bhanjanagar, Narendrapur area. Therefore, flow became zero on all the 220kV lines and bus


became dead at Jeypore, Indravati, Jayanagar, Theruvali, and Bhanjanagar & Narendrapur S/s. Due to tripping of above mentioned lines and units approx. 550 MW load loss and 60 MW generation loss (running units of Balimela & U.Kolab) occurred in south Orissa system mainly at Bhanjanagar, Theruvali, Narendrapur and its surrounded area. Relay indications are as follows:

Time Name of the Line Local end Remote end 12:17 hrs 400KV Indravati -

Rengali line Transient Fault: C-N,

120.6Km from Indravati, Received direct trip from

Rengali

Transient Fault: C-N Fault Location 199.4 kM A/R unsuccessful due to

high voltage. 12:23:19 hrs 400KV Jeypore-Bolangir

Line O/V St-I, R-Ph at Jeypore

end. DT received at Bolangir

end 12:23:19 hrs 400KV Indravati-Jeypore

Line hand tripped from

Indravati end Over Voltage Stage-1 at

Jeypore 12:29:48 hrs 400KV Jeypore-

Gajuwaka Line - I DT recieved Hand tripped from

Gajuwaka end 12:29:32 hrs 400KV Jeypore-

Gajuwaka Line - II DT recieved Hand tripped from

Gajuwaka end

12:23 hrs

220/132kV ATR-I,& II at Jayanagar

Tripped from 220kV side on over flux

220/132kV ATR-I,& II at Bhanjanagar

Tripped from 220kV side on over flux

Balimela U #5 Tripped

U.Kolab U# 2 & 3 Tripped on over flux


Analysis of PMU data: At 12:17hrs,

• From Jeypore PMU plot 80kV voltage dip has been observed in B-Ph at 12:17 hrs. • Fault clearance time was less than 100 ms. • Oscillation started and voltage at Jeypore had reduced drastically from 380kV 240kV.

At 12:23 hrs, • Jeypore voltage had started building and at 12:23 hrs it went upto 450kV.


OPTCL and Powergrid may explain. Deliberation in the meeting Powergrid explained that-- • At 12:17 hrs, 400KV Indravati - Rengali S/c line tripped on transient SLG (i.e. C-N) fault. • Auto reclose operation was successful at Indravati end but unsuccessful at Rengali end due to

over voltage at Rengali. • Hence, after few millisecond, the line tripped from Indravati end also on receipt of direct trip

from Rengali end. • After the incident there was oscillations in the system and huge over voltage was observed and

the following elements were tripped:

1) 400KV Jeypore-Bolangir line (tripped on high voltage from Jeypore) 2) 400KV Indravati-Jeypore line (tripped on high voltage from Jeypore) 3) 220/132kV ATR-I,& II at Jayanagar (tripped on over flux) 4) 220/132kV ATR-I,& II at Bhanjanagar (tripped on over flux) 5) Running units #2& 3 of U.Kolab (tripped on over flux) 6) Running unit #5 of Balimela

PCC felt that similar incident was happened on 10-03-16 at 12:24 hrs to 12:31 hrs and severe oscillations, high voltage were observed in south odisha system during the disturbance. The details from HVDC Gajuwaka end are also not available for detailed analysis of the disturbance. PCC advised Powergrid to carry out the following and submit a detailed report: Check the reason for high voltage at 400kV Rengali end during auto reclose operation in

400kV Indravati-Rengali line Collect the details of all the events from HVDC Gajuwaka end during the disturbance


Detailed analysis for the reason of high voltage at Jeypore and adjoining areas.& also for the

oscillations observed in the system. Powergrid agreed. PCC also felt that the PDO conditions of HVDC Gajuwaka needs to be reviewed after detail study of the S. Odisha system.

B.1.8: Uncoordinated tripping of 400kV Meeramandali- Mendhasal S/c line during month of March- April-2016.

List of repeated uncoordinated tripping of 400kV Meeramandali- Mendhasal S/c line occurred during month of March- April-2016 enclosed at Annexure-B1.8. OPTCL may explain. Deliberation in the meeting OPTCL submitted a report on above uncoordinated tripping of 400kV Meeramandali- Mendhasal S/c. The report is enclosed at Annexure-B1.8.1. Item No B.2. Disturbance in BSPTCL System

B.2.1: Total Power failure at 220/132kV Purnea (PG/BSPTCL) & Madhepura S/s on

18-04-16 at 20:15 hrs. At 20:15 hrs, 132KV Madhepura-Supaul ckt II line was tripped with distance relay indication of zone 3, 77.9 KM from Madhepura GSS end. Consequently, 132kV Madhepura- Supaul line-I tripped on over current protection. Thereafter, the following lines were tripped on over current protection:

• 132kV Forbesganj-Kataiya-I,II,III • 132kV Purnea(BSPTCL)-Forbesganj • 132 KV Purnea(PG)-Purnea ckt-I,II,III tripped on relay indicating O/C at Purnea(PG). • 132kV Purnea(PG) - Kishanganj S/C



Time (Hrs)

Details of tripping Relay at local end Relay at remote end

20:14 hrs

132kV Madhepura- Supaul line-II zone 3, B,77.9 KM from Madhepura

NA

132kV Madhepura- Supaul line-I O/C

132kV Forbesganj-Kataiya-I,II,III O/C

132kV Purnea(BSPTCL)-Forbesganj O/C

132kV Purnea(PG)- Purnea(B)-I,II & III

At Purnea(PG) Tripped on O/C

(As informed by PGCIL)

At Purnea(B) Did Not Tripped

132kV Purnea(PG) - Kishanganj S/C At Purnea(PG) Tripped on O/C


At Kishanganj Did Not Tripped


• From the Biharshariff & Sasaram PMU plot no signature of any type of fault has been observed.

BSPTCL and Powergrid may explain. Deliberation in the meeting BSPTCL informed that 132KV Madhepura-Supaul ckt II line was tripped on zone 3 distance protection due to mal-operation of relay. The power flow in the line was 70 MW prior to the fault. After tripping of 132KV Madhepura-Supaul line-II, 132KV Madhepura-Supaul line I got over loaded and tripped on overcurrent protection. Thereafter, the following lines tripped on overcurrent protection due to increase in power flow:

• 132kV Forbesganj-Kataiya-I,II,III • 132kV Purnea(BSPTCL)-Forbesganj • 132 KV Purnea(PG)-Purnea ckt-I,II,III. • 132kV Purnea(PG) - Kishanganj S/C

PCC advised BSPTCL to test the distance protection of 132KV Madhepura-Supaul ckt II at Madhepura end. PCC felt that BSPTCL 132kV system in around Madhepura and Purnea is being operated at optimum level and tripping of any one line is resulting cascade tripping of other lines on overcurrent due to over load. PCC advised BSPTCL to implement SPS as a temporary arrangement to control the cascade tripping of the transmission lines till new transmission lines were commissioned.

B.2.2: Total Power failure at 220/132kV Purnea & Madhepura S/s on 28-04-16 at 19:23 hrs.

At 19:23 hrs, Y-Ph CT of 33kV side of 132/33kV, 50 MVA ATR-I at Purnea (B) busted and all the 132kV lines emanating from 132kV Purnea (PG) S/s such as Purnea (PG)- Purnea (B) – T/C & Purnea (PG)- Kishanganj S/c tripped on actuation of overcurrent protection from PGCIL end. 132kV Madhepura- Supaul D/c line also tripped.



Time (Hrs)


19:23 hrs

132kV Purnea(PG)- Purnea(B)-I,II & III

At Purnea(PG) Tripped on O/C


At Purnea(B) Did Not Tripped

132kV Purnea(PG) - Kishanganj S/C At Purnea(PG) Tripped on O/C


At Kishanganj Did Not Tripped

132kV Madhepura- Supaul D/C Tripped on O/C (As informed by BSPTCL through telephonic conversation)


• From the Biharshariff PMU plot 12kV voltage dip has been observed in both R & Y-Ph at 19:21 hrs.

• Fault clearance time was less than 100 ms. BSPTCL may explain the following:

• Non clearance of the fault from 132kV side of 132/33kV ATR-I at Purnea (B) • BSPTCL may explain tripping 132kV Madhepura- Supaul D/c lines also furnish the distance

& overcurrent settings of 132kV Madhepura- Supaul D/c lines Deliberation in the meeting BSPTCL informed that Y-Ph CT of 33kV side of 132/33kV, 50 MVA ATR-I at Purnea (B) busted and the ATR protection failed to clear the fault as tripping coil of the ATR-II was burnt. BSPTCL informed that now the tripping coil has been replaced. PCC advised BSPTCL to implement the supervision of trip coil in their control panels and to monitor it properly. Item No B.3. Total Power failure at 220/132kV Hatia S/s of JUSNL system on 20-04-16

at 15:05 hrs.

At 14:57 hrs, SLG (i.e. B-N) fault had occurred in 220kV Ranchi- Chandil S/c line near to Chandil S/s. And due to delayed clearance of the fault from Ranchi S/s, the other 220kV lines emanating from Hatia S/s such as 220kV Ranchi- Hatia D/c lines tripped from Hatia end. Thereafter running unit of Patratu (U#10 ) tripped due to heavy electrical jerk. Relay indications are as follows:

Time (Hrs)


14:57 hrs

220kV Ranchi- Chandil S/c

At Ranchi Tripped

At Chandil B-P, Zone-I, Fault location- 38.22 KM, Earth Fault

220kV Hatia- At Ranchi AT Hatia


Ranchi-I Did not Tripped Earth Fault 220kV Hatia- Ranchi-II

At Ranchi Did not Tripped

AT Hatia Earth Fault

Patratu U# 10 Due to electrical Jerk 15:05-15:10 hrs

220kV PTPS- Hatia –I

At Hatia O/V

At PTPS Did Not Trip

220kV PTPS- Hatia –II

At Hatia O/V

At PTPS Did Not Trip

132kV PTPS- Hatia-I

At PTPS O/C

At Hatia Did not Tripped

132kV PTPS- Kanke-Hatia-

At PTPS O/C

At Kanke Did not Tripped

220kV PTPS- TTPS S/c

At PTPS O/V

At TTPS Did not Tripped

TTPS U # 2 Tripped on O/V Analysis of PMU plots:

• From the Ranchi PMU plot 9kV Voltage dip has been observed in B-Ph at 14:57 hrs. • Fault clearance time was approx.440 ms.

JUSNL and Powergrid may explain the following:

• Delayed tripping of Ranchi- Chandil S/c line from Ranchi end may be investigated and explain by PGCIL.

• Tripping of 220kV Patratu- Hatia D/c line and 220kV PTPS- TTPS S/c from Hatia end on over voltage

• Tripping of 132kV PTPS- Kanke-Hatia line from PTPS end on over current • Status of 220/132kV ATRS at Hatia (tripped or not).


Deliberation in the meeting The issue could not be discussed as JUSNL representatives were not available. Item No B.4. Disturbance at 132kV Jeerat and Bandel S/s on 10.04.16 at 13:13 hrs WBSETCL informed that there was a C ph-N fault (close to Jeerat end) in 132kV Jeerat-Mohispota line (under construction), which was idle charged from Jeerat end. Jeerat end failed to clear the fault. As a result the following lines tripped:

• All the three 160 MVA, 220/132kV ATRs at Jeerat tripped from LV side non-directional over current protection.

• 132kV Jeerat-Dharmpur D/C lines tripped from Dharmpur end on over current earth fault protection (C-N). The fault clearing time of line 1 is 1.562 s and line 2 is 1.602 s.

Simultaneously, another C ph-N fault was occurred in 132kV Bandel-Dharmpur line I at 4.4 km from 132kV Bandel S/s. The fault was cleared from Bandel end on zone 1 distance protection and tripped from Dharmpur on over current E/F protection. The fault clearing time from Dharmpur end was 90 ms.

However, the 132kV Bandel-Dharmpur line II & III and 132kV Bandel-Kalyani line also tripped from Bandel end on over current protection and Bandel Unit #5 motor feeder tripped on over voltage. As a result, U#5 tripped on flame failure. WBPDCL added that they have definite time setting in over current protection at 132kV Bandel S/s with 1 s time delay. The disturbance was discussed in special meeting held on at ERPC, Kolkata on 3rd May, 2016 wherein, WBSETCL informed that there was a C ph-N fault (close to Jeerat end) in 132kV Jeerat-Mohispota line (under construction), which was idle charged from Jeerat end. Jeerat end CB failed to trip the line. After detailed deliberation, concluded the tripping incidence as follows: The distance protection at Dharampur end of 132kV Jeerat-Dharampur D/C lines which was supposed to clear the fault (near to 132kV Jeerat S/s) in zone 2/zone 3 has failed and over current earth fault protection at Dharampur end took more than 1.5 s to clear the fault. As a result, the fault got fed from Bandel TPS through 132kV Bandel-Dharampur line II & III and 132kV Bandel-Kalyani-Dharampur lines. Since over current protection settings at 132kV Bandel and Kalyani S/s of these


lines is Definite time with 1 s delay which is less than the fault clearing time (which is more than 1.5 s) at Dharampur end, the lines were tripped from Bandel end before the fault got cleared from Dharampur end. In order to avoid such uncoordinated trippings, the committee recommended the following:

• WBSETCL was advised to cover the total line length of the 132kV Jeerat-Mohispota (under construction) line in zone 1 from Jeerat end.

• WBSETCL was advised to review the distance protection settings of 132kV Jeerat-Dharampur D/C line and 132kV Bandel-Dharampur line at Dharampur end.

• It was observed that over current earth fault protection characteristics of 132kV Jeerat-Dharampur D/C lines at Dharampur end were IDMT characteristics and over current protection characteristics of 132kV Bandel-Dharampur line I, II & III and 132kV Bandel-Kalyani at 132kV Bandel end were Definite time characteristics.

• It was felt that characteristics of over current relays should be identical for proper relay coordination. WBPDCL was advised to review the over current settings at Bandel end as per the OEM requirement of Bandel generators. Accordingly, WBSETCL to set the identical characteristics at 132kV Kalyani and Dharampur S/s and coordinate the relays by selecting proper time delay.

• WBPDCL and WBSETCL agreed to coordinate and resolve the issue bilaterally. WBPDCL and WBSETCL may update. Deliberation in the meeting WBPDCL and WBSETCL informed that the overcurrent settings will be reviewed at the earliest in their joint meeting. Item No B.5. Tripping incidences in the month of April, 2016 Other tripping incidences occurred in the month of April, 2016 which needs explanation from constituents of either of the end is given at Annexure- B.5. Members may discuss. Deliberation in the meeting Members explained the tripping incidences. Updated list is enclosed at Annexure- B.5. Item No B.6. Protection Committee visit to BSPTCL and JUSNL Sub-stations In view of repeated uncoordinated trippings in BSPTCL and JUSNL systems, a committee of following protection engineers was formed to review the situation:

• Shri Sabyasachi Roy, ACE, WBSETCL, • Shri L Nayak, GM, OPTCL • Shri Jayanta Datta, SE, DVC • Shri Surajit Bannerjee Asst GM, ERLDC, • Shri S. K. Singh, DGM, PGCIL (in place of Shri J. Das, PGCIL) • Shri S. B. Prasad, ESE, BSPTCL • Shri Vidyasagar Singh, ESE, JUSNL

PCC needs the following information in respect of Chandil, Ramchandrapur, Adityapur and adjoining substations in Jharkhand and New Purnea, Madhepura, Biharshariff and adjoining substations in Bihar.

1. SLD of all the affected and surround Sub-station (with CT location) Minutes of 43rd PCC meeting 20

2. Year of manufacture of all equipments 3. Comprehensive CT details along with name plate (with connected/adopted ratio ) 4. VT details 5. Fault level- 3-phase as well as 1-phase (line length, conductor details and Transformer

details for computing fault level) 6. Transformer detail (Rating, impedance) 7. Availability of Auto-Reclosure feature 8. Availability of carrier protection 9. Availability of Bus- differential and LBB Protection 10. Junction Box (JB) details 11. Cable details used for CT connections (Cross section/core of cable, Junction Box (JB)

details & length of cable between JB & control panel) 12. Grid earthing resistance (With latest test report) 13. Breaker details (operating time) 14. CT/PT earthing details 15. Relay details (Relay type, model, settings, manufacturing, basis of settings) 16. Scheme adopted for protection settings for lines and transformers 17. DC system details with charger and battery

In a special meeting held on 8th December, 2015 and PCC meetings, BSPTCL and JUSNL advised to submit the pending details. BSPTCL and JUSNL have submitted the details. In 41st PCC, the Protection team has presented a preliminary study report regarding the data as submitted by JUSNL and BSPTCL. As decided in PCC, a special Meeting was convened on 29th Mar, 2016 to review the data submitted by BSPTCL & JUSNL and also to discuss the road map for the site visit. JUSNL and BSPTCL had submitted all the requisite data as desired by the Protection Team. The observations as submitted by Protection team in its preliminary study were discussed in detail. The remedial action taken by JUSNL and BSPTCL was reviewed by the protection team and recommendations were advised. The minutes of the meeting is already available at ERPC website. The protection team advised JUSNL and BSPTCL to initiate the implementation of the recommendations however, the final report with recommendations will be given after the complete study and site visit of the listed sub-stations. It was also decided that the team will start the site visit from the month of April, 2016. The site visit plan will be formulated in consultation with the team members and will be intimated to JUSNL and BSPTCL in due course. PCC decided that the protection committee members will carry out the site visit of JUSNL substations during 11th to 14th May, 2016 to review the protection system in respect of Chandil, Ramchandrapur, Adityapur and adjoining substations. The Protection team has visited 132/33 kV Ramchandrapur, Adityapur & 220/132 kV Chandil S/s of JUSNL from 11th to 12th May, 2016 BSPTCL and JUSNL may update. Deliberation in the meeting It was informed that the Protection team has visited 132/33 kV Ramchandrapur, Adityapur & 220/132 kV Chandil S/s of JUSNL from 11th to 12th May, 2016. PCC advised to convene a special meeting with JUSNL to discuss the observations of above site visit and place the report.


Item No B.7. PROTECTION PHILOSOPHY OF EASTERN REGION The Protection Philosophy finalized in special PCC meeting held on 20th July, 2015 is as given below:

Sl. No.

Zone Direction Protected Line Reach Settings

Time Settings (in Seconds)

Remarks

1 Zone-1 Forward 80% Instantaneous (0) As per CEA

2a Zone-2 Forward For single ckt- 120 % of the protected line

0.5 to 0.6 - if Z2 reach overreaches the 50% of the shortest line ; 0.35- otherwise

As per CEA

For double ckt- 150 % of the protected line

As per CEA

2b Zone-2 (for 220 kV and below

voltage Transmission

lines of utilities)

Forward 120 % of the protected line, or 100% of the protected line + 50% of the adjacent shortest line

0.35 As per CEA with minor changes

3 Zone-3 Forward 120 % of the (Protected line + Next longest line)

0.8 - 1.0 As per CEA

4 Zone-4 Reverse 10%- for long lines (for line length of 100 km and above) 20%- for shot lines (for line length of less than 100 km)

0.5

As per CEA

Note: 1) Zone-2:- Z2 Reach should not encroach the next lower voltage level. 2) Zone-3:- If Z3 reach encroaches in next voltage level (after considering “in-feed”), then Z3 time

must be coordinated with the fault clearing time of remote end transformer. 3) Zone-4:- If utility uses carrier blocking scheme, then the Z4 reach may be increased as per the

requirement. It should cover the LBB of local bus bar and should be coordinated with Z2 time of the all other lines.

4) The above settings are recommended primarily (exclusively) for uncompensated lines. All the constituents agreed on the principles read with notes as above. Till date DVC, WBSETCL, JUSNL, OPTCL, Powergrid (ER-I, ER-II & Odisha-Projects), NTPC, BSPTCL, NHPC, Vedanta and GMR had submitted the zone settings. PCC advised all the other constituents to implement the revised zone philosophy and submit the settings to ERPC at the earliest. IPPs may submit the revised zone settings data at the earliest. Deliberation in the meeting PCC advised all the IPPs to implement the revised zone philosophy and submit the settings to ERPC at the earliest. Minutes of 43rd PCC meeting 22

Item No B.8. Third Party Protection Audit 1. Status of 1st Third Party Protection Audit:

The compliance status of 1st Third Party Protection Audit observations is as follows:

Name of Constituents Total Observations Complied % of

Compliance Powergrid 54 37 68.52 NTPC 16 14 87.50 NHPC 1 1 100.00 DVC 40 26 65.00 WB 68 27 39.71 Odisha 59 38 64.41 JUSNL 34 16 47.06 BSPTCL 16 5 31.25 IPP (GMR, Sterlite and MPL) 5 5 100.00

The substation wise status of compliance are available at ERPC website (Observations include PLCC rectification/activation which needs a comprehensive plan).

Members may update. Deliberation in the meeting PCC advised all the constituents to comply the observations at the earliest. 2. Schedule for 2nd Third Party Protection Audit:

The latest status of 2nd Third Party Protection audit is as follows:

1) Jeerat (PG) Completed on 15th July 2015 2) Subashgram (PG) Completed on 16th July 2015 3) Kolaghat TPS (WBPDCL)- Completed on 7th August 2015 4) Kharagpur (WBSETCL) 400/220kV - Completed on 7th August 2015 5) Bidhannagar (WBSETCL) 400 &220kV Completed on 8th September, 2015 6) Durgapur (PG) 400kV S/s Completed on 10th September, 2015 7) DSTPS(DVC) 400/220kV Completed on 9th September, 2015 8) Mejia (DVC) TPS 400/220kV Completed on 11th September, 2015 9) 400/220/132kV Mendhasal (OPTCL) Completed on 2nd November, 2015 10) 400/220kV Talcher STPS (NTPC) Completed on 3rd November, 2015 11) 765/400kV Angul (PG) Completed on 4th November, 2015 12) 400kV JITPL Completed on 5th November, 2015 13) 400kV GMR Completed on 5th November, 2015 14) 400kV Malda (PG) Completed on 23rd February, 2016 15) 400kV Farakka (NTPC) Completed on 24th February, 2016 16) 400kV Behrampur(PG) Completed on 25th February, 2016 17) 400kV Sagardighi (WBPDCL) Completed on 25th February, 2016 18) 400kV Bakreswar (WBPDCL) Completed on 26th February, 2016

Members may note. Deliberation in the meeting Members noted. Minutes of 43rd PCC meeting 23

Item No B.9. Implementation of Protection Database Management System Project. ERPC proposal for “Creation & Maintenance of web based protection database management system and desktop based protection calculation tool for Eastern Regional Grid” has been approved by the Ministry of Power for funding from Power System Development Fund (PSDF) vide No-10/1/2014-OM dated 07.03.2016. Subsequently, the LOA was given to PRDC and the first implementation meeting was held on 12.04.2016. Operational load flow requisite data format is available in ERPC website. All the constituents are requested to submit the filled formats at the earliest and co-operate for smooth implementation of the project in time bound manner. In last PCC, all the constituents were advised to submit the filled formats at the earliest. Members may note and co-operate. Deliberation in the meeting Members noted.

PART- C FOLLOW-UP OF DECISIONS OF THE PREVIOUS PROTECTION SUB-COMMITTEE MEETING(S)

(The status on the follow up actions is to be furnished by respective constituents) ITEM NO. C.1: Total power failure at 400kV Mendhasal S/s of OPTCL system on 30-03-16 at

16:59 hrs. At 16:59 hrs, 400kV Meeramandali- Mendhasal S/c tripped due to occurrence of SLG fault (i.e. R-N fault) from Meeramandali end. Simultaneously, other 400kV lines emanating from Mendhasal s/s such as Mendhasal- N .Duburi S/c & Mendhasal- Baripada S/c were also tripped (relay indications not available). After tripping of above mentioned lines, MW flow on both 400/220kV, 315 MVA ICTs at Mendhasal became zero. 400kV bus became dead at Mendhasal S/s and approx. 400 MW load loss occurred at Chandaka and its surrounded area. In 42nd PCC, OPTCL explained that the presently the voltage is being measured from Phase to earth which might have measured high voltage during fault and caused for tripping of 400kV Mendhasal- N. Duburi S/C and 400kV Mendhasal - Baripada S/C lines on over voltage. Therefore, they have changed the relay input voltage from ph-earth to ph-ph voltage. PCC felt that the voltage of other phases would increase during line-to-ground fault, if earthing of CVT secondary is improper. PCC advised OPTCL to check the CVT secondary earthing. OPTCL agreed.


OPTCL may update. Deliberation in the meeting PCC advised OPTCL to check the CVT secondary earthing at the earliest. ITEM NO. C.2: Disturbance in 220kV WBSETCL & CESC on 01-03-16 at 09:31 hrs. At 09:31 hrs, all the 220kV lines connected to Main Bus-I of Subhasgram (PG) S/s (i.e. 220kV Subhasgram (PG) - Subhasgram (WB) D/C, Subhasgram (PG) - CESC-II & Subhasgram (PG) - New Town S/c) tripped due to mal-operation of LBB protection. At 09:39 hrs, 220kV Jeerat- Kasba line-I tripped on zone 1, Y-ph fault from both ends but 220kV Jeerat- Kasba line-II was tripped from Jeerat end only on indication of Z-I, Y-Ph. After tripping of 220kV Subhasgram(PG)-Subhasgram (WB) D/c and 220kV Jeerat-Kasba D/c lines, part of WBSETCL network along with CESC system got isolated from the ER grid and around 180 MW power was being exported to the part of WBSETCL network from CESC’s EM Substation through 132 KV EMSS (CESC) – Kasba (WBSETCL) circuits. Hence, the frequency of the CESC System sharply dipped to 47.7 Hz leading to load shedding of around 200 MW within CESC’s network through UFR operation at various Substations. At the same time, 132 kV Bus Coupler- I at EMSS tripped through SPS for Islanding Scheme (triggered by U/F relay at 47.8 Hz) by which the CESC system has finally isolated from WBSETCL System. Due to loss of 200 MW (load shedding through U/F relays) & 180 MW of WBSETCL load (due to final isolation of WBSETCL Kasba S/S from CESC system) caused sudden rise of frequency in islanded CESC system which was arrested by reduction of Budge-Budge generation through operation of HP/LP bypass system. Later CESC System was synchronized at WBSETCL Howrah Point at 09:46 hrs. In special meeting held at ERPC, Kolkata on 3rd May, 2016, It was felt that while carrying out maintenance bus isolator along with LBB link of particular breaker should be kept opened in order to avoid the unwanted operation of LBB during breaker maintenance. Moreover, Powergrid kept both the 220kV Subhasgram (PG)- Subhasgram (WB) D/C lines in Main Bus-I which resulted in isolation of CESC system from 220kV Subhasgram (PG) on operation of LBB protection. Members advised Powergrid to follow standard maintenance practice in future and not to keep the 220kV Subhasgram (PG)- Subhasgram (WB) D/C lines both on the same bus. Powergrid agreed to take care in future. Powergrid informed that the provision of DT is not available in 220 kV WBSETCL lines. Further it was informed that 220kV Subhasgram(PG)-Subhasgram(WB) line is a short line and it is difficult to coordinate using distance protection. But the differential protection is yet to be installed in 220kV Subhasgram(PG)-Subhasgram(WB) line. The members advised WBSETCL to implement DT feature for all the lines and implement the differential protection for 220kV Subhasgram(PG)-Subhasgram(WB) line. Members may note. Deliberation in the meeting WBSETCL informed that the action has been initiated to comply the above.


ITEM NO. C.3: Total Power failure at 220kV Kasba S/s of WBSETCL system on 19-03-16 at

16:53 hrs. At 16:53 hrs, SLG (i.e R-N) fault occurred in 220kV Jeerat- Kasba –II near to Kasba but Kasba end failed to clear the fault. Subsequently, 220kV Jeerat-Kasba-I, Subhasgram (PG)- Subhasgram (WB) D/C & Subhasgram (PG)- Bantala S/C lines tripped on directional earth fault relay. CESC got separated from West Bengal system and later it was synchronized at Howrah Point at 17:03 hrs. 42nd PCC decided to convene a separate meeting with Powergrid, WBSETCL and CESC at ERPC Conference Hall on 3rd May, 2016 at 11:30 hrs. Accordingly, a separate meeting was held at ERPC, Kolkata on 3rd May, 2016, wherein WBSETCL explained that there was R-N fault at 220kV Kasba bus due to dropping of some foreign particles. As there is no bus-bar protection available at 220kV Kasba S/s, the fault got cleared from remote ends on zone 2 distance protection. WBSETCL added that 220kV Kasba-Subhasgram(WB) D/C lines were also tripped from Subhasgram (WB) end on zone 2 distance protection. Powergrid informed that directional earth fault relays at Subhasgram (PG) end of 220kV Subhasgram (PG)- Subhasgram (WB) D/C and 220kV Subhasgram(PG)- Bantala S/c had picked up the fault but did not trip. It was felt that the tripping was in order.Hhowever WBSETCL was advised to implement bus bar protection at 220kV Kabsa S/s as it is an important 220 kV interconnecting Sub-station. Powergrid informed that repeated trippings are being occurred in 220kV Jeerat-Kasba D/C line which are being fed through Subhasgram ICTs.. WBSETCL was requested to take the corrective measures to reduce the trippings. WBSETCL agreed. CESC informed that there is a need for time co-ordination between CESC and WBSETCL systems at CESC interconnection points (132kV Howrah and Kasba S/s). It was felt that 33kV and below voltage level feeders of CESC should be allowed to trip first, then 132kV CESC-WBSETCL interconnectors. Therefore, WBSETCL and CESC were advised to co-ordinate the over current time settings bilaterally and resolve the issue. Members may note. Deliberation in the meeting WBSETCL and CESC informed that the meeting is yet to be convened to resolve the issue. ITEM NO. C.4: Multiple elements tripping at 400kV Bidhannagar S/s of WBSETCL system on

30-03-16 at 16:25 hrs. At 16:25 hrs, R-Ph CT connected to Bus-A of bus coupler bay at 400kV Bidhannagar S/s busted due to the inclement weather condition. All the elements connected to the Bus-A were tripped from remote end. Simultaneously, the bus differential protection of Bus-B had operated and tripped all the elements connected to Bus-B of 400kV Bidhannagar S/s from local end. 400kV bus became


dead at Bidhannagar. In 42nd PCC, WBSETCL informed that R-Ph CT of bus coupler bay at 400kV Bidhannagar S/s busted due to the inclement weather condition. The bus differential protection of Bus-B was operated and all the elements connected to the Bus-A were tripped from remote end. PCC felt that since the fault was in common zone of the bus differential protection, the differential protection for both Bus-A & B should have operated to clear the fault immediately. PCC advised WBSETCL to check the bus differential scheme at 400kV Bidhannagar S/s. WBSETCL may update. Deliberation in the meeting WBSETCL informed that the bus differential scheme at 400kV Bidhannagar S/s will be checked on getting opportunity shutdown. ITEM NO. C.5: Tripping of 400kV Subhasgram(PG)-Haldia Line I & II due to over voltage. CESC vide letter dated 12.04.16 informed that 400kV Subhasgram(PG)-Haldia Line I & II tripped on 9-02-2016 at 03:37 hrs due to over voltage at 400kV Subhasgram(PG) S/s. This has caused tripping of both HEL units. However, 400kV Sagardhigi-Subhagram(PG) line was not tripped for the over voltage. CESE requested for review of over voltage relay setting of 400kV Subhasgram(PG)-Haldia Line I & II at Subhasgram(PG) to avoid simultaneous tripping of both the lines. Present setting: 110% with 5 sec delay for both the lines Revised setting: 112% and 110% with 5 sec delay for line I & II respectively. Powergrid and CESC may explain and Members may decide. CESC vide letter dated 27th April, 2016 communicated the revised settings as follows: At 400kV Subhasgram(PG) end 400kV Subhasgram(PG)-Haldia Line I 112% 5 sec (Stage-I) 150% 0.1 sec (Stage-II) 400kV Subhasgram(PG)-Haldia Line II 110% 5 sec (Stage-I) 150% 0.1 sec (Stage-II) At 400kV Haldia end 400kV Subhasgram(PG)-Haldia Line I 110% 5 sec (Stage-I) 140% 1 sec (Stage-II) 400kV Subhasgram(PG)-Haldia Line II 110% 3 sec (Stage-I) 140% 1 sec (Stage-II) Members may note. Deliberation in the meeting Members noted. ITEM NO. C.6: Frequent Blackouts at Kanti TPS On 7th April, 2016, total station power failure (Blackout) incident has occurred at Kanti TPS. There was some fault at 220KV Gopalganj side from Kanti TPS Switchyard and 220kV Muzaffarpur-Kanti


D/C line tripped on Zone 3 before fault was cleared from Kanti TPS end. This had resulted in total power failure at Kanti TPS leading to Emergency situation with hot turbine coasting down without normal lub oil supply. A special meeting was convened at ERPC, Kolkata on 18-04-2016 and the following decisions were taken:

a) As a temporary measure, zone 1 and zone 2 time setting of all 220kV and 132kV lines at Kanti TPS end should be changed to instantaneous and zone 3 time setting as 200ms in order to clear the downstream faults from Kanti TPS end.

b) Powergrid was advised to change the zone 3 time settings at Muzaffarpur (PG) end as per protection philosophy of ERPC.

c) NTPC and Powergrid were advised to activate the PLCC scheme for 220kV Muzaffarpur-Kanti D/C by 26th April, 2016 and give feedback in 42nd PCC Meeting.

d) On activation of PLCC system, Powergrid is to change the zone 2 time setting at Muzaffarpur (PG) end as per protection philosophy of ERPC.

e) BSPTCL was advised to check the clearance between cross arm and jumper and rectify if required.

f) BSPTCL was advised to review the protection system and relay coordination of 220kV Gopalgunj, Darbhanga and Begusarai and all 132kV feeders in around Kanti. Therefore, BSPTCL was advised to submit their relay details to Powergrid by 22nd April, 2016 for review. Powergrid was requested to study the details and give feedback in 42nd PCC Meeting scheduled to be held on 27th April, 2016.

g) It was decided that the above temporary measure will be followed, till BSPTCL protection system is full proof.

h) Further course of action will be decided in PCC Meeting for relay coordination in BSPTCL system in and around Kanti TPS.

In 42nd PCC, Kanti TPS, NTPC informed that zone settings at their end have been revised as per the recommendation. Regarding activation of PLCC scheme for 220kV Muzaffarpur-Kanti D/C line NTPC informed that cabling has been done but some parts in PLCC panels were defective and needs to be replaced. Powergrid informed that they have not yet revised the zone 3 time setting at Muzaffarpur (PG) end. PCC advised Powergrid to revise the zone 3 time setting at Muzaffarpur (PG) end as per protection philosophy of ERPC at the earliest. PCC also advised Powergrid to implement the PLCC scheme for 220kV Muzaffarpur-Kanti D/C line at the earliest. Members may update. Deliberation in the meeting PCC advised Powergrid to revise the zone 3 time setting at Muzaffarpur (PG) end as per protection philosophy of ERPC at the earliest and submit the latest status on the above action plan. ITEM NO. C.7: Total power failure at 220kV Chandil S/s of JUSNL system on 24/02/16 at

16:59hrs At 16:59hrs, the R-ph jumper of 220kV side main bus to isolator of 100 MVA, ICT-IV burnt and grounded which caused a bus fault at 220kV Chandil S/s. In 41st PCC, JUSNL was advised to ensure the protection healthiness of 220/132 kV ATRs I & II by


replacing the old EM relays. On query WBPDCL informed that none of the protection has operated at Santaldih end of 220 kV Chandil –Santadih line. PCC felt that Santaldih end has failed to detect the fault in zone-II and advised WBPDCL to check & review the zone settings of 220 kV Chandil –Santadih line at Santaldih end. In 42nd PCC, WBPDCL informed that the settings of 220 kV Chandil –Santadih line at Santaldih end will be reviewed on opportunity shutdown. JUSNL and WBPDCL may update. Deliberation in the meeting WBPDCL vide mail dated 20th May 2016 informed that settings at Santadih end have been verified and the relay has been tested. No abnormality observed in the relay. ITEM NO. C.8: Disturbance at 220/132kV NJP S/s of WBSETCL system on 29.02.16 at 03:55

hrs. WBSETCL reported that at 03:55 hrs, 220/132kV, 160 MVA TR-I,II & III, 220kV NJP-TLDP (IV)- I & II and 220kV Binaguri (PGCIL)- NJP Bus Section-A & B were tripped due to over voltage. 220kV bus voltage was recorded as 254 kV and 132kV bus voltage was recorded as 148 kV ay NJP. Powergrid reported that 125 MVAR bus reactor-2 tripped at Binaguri end on Y ph differential protection and reactor Buch relay/PRV/WT1/OTI trip. After physical inspection, it is observed that R & Y phase bushing was heavily cracked from Turret/Bottom and B phase bushing was totally burst and heavy oil leakage was observed. The tripping details are as follows:

Time (Hrs)


03:55 hrs

220/132kV, 160 MVA TR-I,II & III at NJP

HV side:- Over flux, 86 L & LV side:- 86 L

220kV NJP-TLDP (IV)- I & II

At NJP High Speed 3-Ph Trip relay (86/LO), Autorecloser L/O

At TLDP (IV) 21 M, 23 Px, PLCC channel

unhealthy, 27 RYB, 30 C, 30 D, 86 A,86 B, Autorecloser

PTS switch relay 220kV Binaguri (PGCIL)- NJP Bus Section-A & B

At (NJP end) Did Not Trip

(as informed by WBSETCL)

At PGCIL (end) Trip Relay 96 BSA, 96 BSB (as informed by WBSETCL)

125 MVAr Bus Reactor-II at Binaguri (PGCIL)

Y-Ph differential relay operated


• No overvoltage has been observed from the Binaguri PMU plot • From the Binaguri PMU plot 175kV dip has been in Y-Ph at around 03:55:39 hrs. • 1.1 KA rise in line current of 400kV Binaguri- Purnea has been observed during the incident.


• Fault clearance time was approximately 80 ms.

In last PCC, WBSETCL informed that there was a high voltage at 220 kV Binaguri and NJP due to which all the ICT and 220kV Binaguri (PGCIL)- NJP Bus Section-A & B were tripped. However, the exact cause of tripping of 220kV NJP-TLDP (IV)- I & II could not be ascertained. Powergrid informed that as per their record there was no over voltage at Binaguri side and all equipments are intact. PCC advised WBSETCL to get the tripping details of 220kV NJP-TLDP (IV)- I & II and submit a report on the incidence. WBSETCL may explain. Deliberation in the meeting PCC advised WBSETCL to get the tripping details of 220kV NJP-TLDP (IV)- I & II and submit a report on the incidence. ITEM NO. C.9: Members may update the following: 1. Powergrid informed that Bus-bar protection at 220kV Birpara S/s will be installed within 2-3

months. In 40th PCC, Powergrid informed that Bus-bar protection at 220kV Birpara S/s will be installed by 2nd week of March 2016. In 42nd PCC, Powergrid informed that the testing of Bus-bar protection is in progress. Powergrid may update. Deliberation in the meeting Powergrid informed that the Bus-bar protection at 220kV Birpara S/s has been commissioned. 2. OPTCL may please update the latest status on following substations:

In last PCC, OPTCL informed that

The issue of LBB maloperation at 220kV Meeramundali S/s at 04:59hrs on 18/09/15 has been taken up with Siemens: Siemens has checked the LBB logic and found ok

OPTCL informed that they will review the logic of all the newly installed LBB protection: Exploring for improvement in logic for tripping of single bus in case of LBB operation

Old distance protection relays in 132kV system at 220kV Tarkera S/s will be replaced after replacing old relays at 220kV level: The replacement work of relays at Tarkera is in progress

OPTCL may update. Deliberation in the meeting OPTCL informed that work is in progress. ITEM NO. C.10: Additional Agenda

1. Major collapse in NER system on 16th April 2016 Minutes of 43rd PCC meeting 30

NER Grid was in synchronism with NEW Grid through 220 kV Birpara - Salakati I & II and 400kV Bongaigaon - New Siliguri I, II, III and IV lines. On 16th April 2016 at around 12:03:29 hrs a B-Ph to earth fault occurred at 400kV Bongaigaon-BTPS (NTPC)-I. Due to delayed fault clearance form Bongaigaon end 400 kV Binagauri-Bongaiagaon 1,2,3,4 tripped from Binaguri end in Zone-2 in 350 millisecond. Later 400kV Bongaigaon- BTPS( NTPC)-I line tripped after 440mS at Bongaigaon from the instant of initiation of fault and 400kV Bongaigaon – BTPS (NTPC) –II tripped after 530mS on carrier Direct Trip receipt from NTPC end. At 12:03:45 hrs +/- HVDC Biswanath Chariali - Agra pole –I got blocked. The 400/220kV 315MVA ICT at Bongaigaon tripped on over current protection on HV Side. 220 kV Salakati-BTPS I & II also tripped at the same time at BTPS end. Due to above trippings NER grid de-synchronized from national grid. 220kV Salakati S/S remained connected with Birpara and Gelephu S/S. Major part of NER grid failed due to load –generation mismatch. It appears that tripping of all the four circuits of 400kV Binaguri –Bongaigaon corridor on Zone-II before clearance of fault of 400 kV Bongaigaon – BTPS (NTPC) line –I from Bongaigaon, seems to be the main cause of the disturbance. As per agreed protection philosophy Zone-2 time setting of 400 kV Binaguri-Bongaigaon Q/C should be 0.5 to 0.6 seconds since Bongaigaon-BTPS is a very short line (Only 3.5 Kms) in compare to 400 kV Binaguri-Bongaigaon. PowerGrid may explain above tripping and action taken to prevent such incidents in future. Deliberation in the meeting Powergrid informed that the information on commissioning of 400kV Bongaigaon-BTPS (NTPC)-I was not available to them. The zone 2 time setting was at 350 ms. Powergrid confirmed that the zone 2 time setting has been revised to 500 ms.

Meeting ended with vote of thanks to the chair.

******************


4^lel\}-fr-'A

Venue: ERPC Conference Room, Kolkata Time: 1l-:00 hrs Date: 23.05.2016 (MondaY)

"Coming together is a beginning, staying tcgether is progress, and working together is success." -Henry Ford

lPage 1l

SignatureEmaitDesignation/Organization

ContactNumber

stNo

Name

/LJ,rtJ"1Q306W3\ me{e-pue,Qnie.L1AK l,,lyil,tty^y /vt< e (/c

. ? t-o;J, qv-(r}

a {L;oSlrl.Lrqe D.o2 U'(' |t""-''-- G*-,Et t5.

>a>-L*fQdaa.d.3

P?. BANDropADlt/A Da*@) Enr.x,

7s/.,4/@7,ta. c,*F S,K) h"lqn&l,nery 1t3Zot4 t8374

l4[",,El@,?r^^.{--w"4*ryD6M, ERDe q\)}o^\gL35

S.BA{.IE(JFJ

41\r6 9903t8'o{2 suJd r^t b oJ (4 P gi "a7'1'l

-6a\,1e I llt%

E, e^) Dr g, e\fl;

4JLt t-,,bbi. L,P, e]*1. "*J'q trt; ]I L"-r., f Vtttn

no6n.yo\,&(Ettd@Jv2 )t1

8 cfi rqoba-"i Re Do/ag-oat,, - a49qL>11)

4,g4734to))2 -./*Ka;4L0rl+c.t .;stc t oa) &[la<A€K It - p1p6 X4

1 w10 1.x,'gua-t cl V ZloLl2N cA,lA4-L/U}@d,(4Aqfi,qya\,n

v.1a E11J .-Dottr. 5l:. O.sgu

CgYs.f Et,I\4 tr9r 5r5{r{

n4,q1\32x5t &12_ -P-dubO6*'*'to'1,2 btt ERLIC

ltR' P krn,gg Yq-le(ttat ,1\Ybu{U n4Prl'-@y''-l^c.-

%l,aq. Ca4ta'Q-I sli^).Uylvt

p41,4 %w K<dl^al.[*reo'x

7\)qarrs(

{-=tk17<Az"*t L Y-.L,.--r@ff2---t z- ,.J\15 (r-,qar DirI(-]P-ca4-+&sa

erz:otu({o(i'ta\.6e@ ld,.

16 ).&,"r*L

?RD (

lAo c

*S3"13tESt{do s a,.I @ orl.|&Q"com1,7 WEPDCL

t )rl-t"^rnJt"rg*'.-^'ffifi_

{ ? q;ti1'--. 4,r1.6MlR. ?7+q496+1

frr--tr? rw.fuvu Wr,Wt't- ?rtU61?03,|,t.vvr4tv-,rywi

\/'CM cLbrb$sk 9\t81o79ot ele . yt<oi,th. (sil1 otf tte@7. i't20

P K Mt slvr^I

Participants in 43'd PCC Meetins of ERPC

S.qsr7o1<ozzszs

N@

71\ ly 1,1Jflf

9

M.k.Thnqyn

9^ \43o .

18

19

Venue: ERPC Conference Room, Kolkata Time: 11:00 hrs Date: 23.05.2016 (Monday)

"Coming together is a beginning, staying together is progress, and working together is success.', -Henry Ford

lPaee 2l

ct

NoName Designation /

OrganizationContactNum ber

EmaiI Signature

27L. N aya! q14, ott? LL 4)t 14,t ,,aaq

'14-22 !.K,\ort *tonlo,t DC,U, OPTLL t4) t1,ryIr,)-

LG t.grtl23 dcMntpMN) 5n.lv Hp'na el

ciEac r-rh '\ qTq37A fLr& tfix*r,fulrbt, L24 'b">aay,pL o'6pt l\7\701tt< * p/*wE ffi25 SvotrTA

a+!-ostlin [es/,uerrrfl2llltesut -J1J.r orrJJp;td- 8.d{"J

26

ff rlr. tc."^S- $€&,w*,w*:t7a 1194qrou> l7t<"^5"LIe tO1*'*; /P27

hail. cE,Thl4 !qzygttxy aczelab @g^)1.c,^ {-428 'R f andro P"a 6c^'l a<-e-ftwl zi6 jt o 41136 y|,.Lth^ @ 1-na.,1.u-29 Pv.-Yybrrgr'fl .=:Ee I Le-\-rL

t>9PTCL?7638t?42) eeacritt QIv,\dJ,,t*,^ W

302E- 22?<- Qfuteqtziz e-rel> -cez@Yd'o' co;r

31D. t(. Br.u'o-i Ee- , Luc etv6t+2t6 euop.e,l>coXwi"

32 e'Nn* b<8, c4tpv(- QqtTrLtru son;la.n^6?e*,li\33 1.N1434

35

36

31

38

39

40

Participants in 43'd pCC Meetins of ERpC

q\3no7&ol

e4- gx$uud.^@\dn otr)

-\44

(. maifi'.

/-t-^-u

q" P,o 4),b4-

Annexure-B1.8

S.No Element name Tripping Date Tripping Time Restoration Date Restoration Time Gen.Loss Load LossFault Clerance Time (As per

PMU)Brief Description

1 400kV Meeramandali- Mendhasal S/c 11/03/2016 12:38 11/03/2016 13:10 NIL NIL < 100 ms

Ttripped on B-N fault. Fault distance 80 KM fault current 4.73 KA

2 400kV Meeramandali- Mendhasal S/c 17/03/2016 14:49 17/03/2016 15:47 NIL NIL 380 ms

Tripped on R-N fault. Zone 2 from Meramundali .Fault current 4.29 KA

Fault Distance 95.2 km from Meramundali.

3 400kV Meeramandali- Mendhasal S/c 27/03/2016 11:29 27/03/2016 11:57 NIL NIL 280 ms Tripped on R-N fault . F/C 4.26 kA, 94.3 km

4 400kV Meeramandali- Mendhasal S/c 28/03/2016 05:13 28/03/2016 16:14 NIL NIL < 100 ms Tripped on R-N fault. ZONE 1 F/C 30.6 kA, F/D 1.2 km from

Meeramandali. (Emergency shutdown was taken)

5 400kV Meeramandali- Mendhasal S/c 30/03/2016 15:33 30/03/2016 16:52 NIL NIL 280 ms Tripped on R-N fault , F/C-4.34 Ka

F/D- 94 Km from Meramundali end

6 400kV Meeramandali- Mendhasal S/c 30/03/2016 16:59 31/03/2016 17:50 NIL NIL 340 ms Tripped on R-N fault , F/C-4.34 Ka

F/D- 94 Km from Meramundali end

7 400kV Meeramandali- Mendhasal S/c 01/04/2016 17:15 09/04/2016 20:50 NIL 340 MW 580 ms

At 17:15 Hrs 400 Kv Meramundali -Mendhasal tripped due to R-N fault .At the same time 400 Kv Mendhasal -New Dubri tripped due to Over voltage protection operated

at Mendhasal end.400 Kv Mendhasal - Baripada also tripped from Mendhasal end only

8 400kV Meeramandali- Mendhasal S/c 12/04/2016 12:40 12/04/2016 13:16 NIL 380 MW 580 ms

At 12:43 hrs, due to transient fault in 220kV Bidanasi- Mendhasal-II )idle charged) all the 400kV feeders emanating

from Mendhasdal S/s i.e. Mendhasal- Meeramnadali, Mendhasal- baripada & Mendhasal- N.Duburi S/c tripped

from remote end.

9 400kV Meeramandali- Mendhasal S/c 15/04/2016 09:30 15/04/2016 10:00

550 MW (Sterlite U#1

& 4)NIL < 100 ms

Due to fault in 400 Kv Sterlite -Meramundali I (R phase CVT of 400 Kv Sterlite -Meramundali I, burst at Meramundali

end), Ckt -I, tripped and 400 Kv Sterlite -Meramundali II was charged only through the tie of 400 Kv Sterlite -Meramundali I at sterlite end so Ckt II also opened from Sterlite end only .

As there is Bus segregation at Sterlite S/S where at Bus-I the elements connected are 400 Kv Sterlite -Meramundali I,

&II and Sterlite Unit II.So as both the circuits tripped ,Unit 2& 4 also tripped due to loss of evacuation path. 400 Kv Meramundali - Mendhasal tripped from Mendhasal end by over-reaching the fault as

fault was in Meramundali s/s.

Repeated Tripping of 400kV Meeramandali- Mendhasal S/c during Month of March-April- 2016

Annexure-B1.8

10 400kV Meeramandali- Mendhasal S/c 26/04/2016 14:48 26/04/2016 15:18 NIL 400 MW Fault Not observe

At 14:48 hrs, 315 MVA 400/220 ICT- I & II at Mendhasal tripped on O/C relay operation, causing tripping of 400KV

Mendhasal-Meramandali line as 400KV Mendhasal-Meramandali was connected through Tie bay of 315MVA

ICT-I (400KV Main bay of 400KV Mendhasal-Meramandali at Meramandali under S/D). 220KV Bhanjnagar-Nayagarh-

Mendhasal was open at Bhanjnagar and 220KV Bhanjnagar-Mendhasal was open at Mendhasal by OPTCL to avoid O/L of 220 Kv Meramundali-Bhanjanagar. This resulted load loss

of 400 MW in Chandaka, Bhubaneswar, Nimapara

11 400kV Meeramandali- Mendhasal S/c 30/04/2016 22:02 30/04/2016 22:53

853 MW ( Sterlite U#1

& 4 (560 MW)

GMR U#3 (243 MW)JSPL (50

MW)

120 MW 200 ms

400KV Sterlite-Meramundali I tripped at 22:02 Hrs due to bursting of Y_ph LA at Meeramandali end. Alongwith this,400KV Bus I & II tripped at Meramundali tripped.

Thereby all elements at 400KV level also tripped. It is is suspected that LBB protection had operated.

Annexure-1.8.1

Annexure-B5

LINE NAME TRIP DATE TRIP TIME RESTORATION DATE

RESTORATION TIME

Fault Clearance

time in msec

Relay Indication LOCAL END

Relay Indication REMOTE END

Auto Recloser statusDR/EL

received within 24

Hrs

DR/EL received after 24

Hrs

Remarks/Brief Reasons

220 KV PUSAULI - SAHAPURI 01.04.16 23:34 03.04.16 12:30approx 440 ms

No Information Received No Information ReceivedNo autorecloser

operation observed in PMU data

No No R-PHASE CT FAILURE AT SAHAPURI(NR), ER-I not available

400KV RENGALI-INDRAVATI 03.04.16 12:06 03.04.16 13:412.1 sec approx

F/C : 2.07 KA, 61.1 km from Rengali, DEF protection

Dir E/F protectionNo autorecloser


YesR-N FAULT (After 2.1 sec further dip observed in Y-Ph), High resistance fault at Indravati less fault current and

voltage dip.

400 KV GAYA -MAITHON - I 05.04.16 11:58 05.04.16 12:25approx 800 ms

R-N, Z-I, F/C : 2.75 KA, 40.5 KM from Gaya

R-N,E/F, F/C -1.8 KA, 254 KM from Maithon

No autorecloser operation observed in

PMU dataYes No R -N FAULT, High resistance fault. PG was advised for

line patrolling.

400 KV GAYA -MAITHON - II 05.04.16 12:29 05.04.16 13:06approx 1.25 sec

B-N, E/F, F/C : 2.35 KA, 41.1 KM from Gaya

B-N, E/F, F/C : 0.8 KA, 206 KM from MTHN


PMU dataYes No B -N FAULT, High resistance fault. PG was advised for

line patrolling.

400 KV GAYA -MAITHON - I 05.04.16 13:08 05.04.16 20:03approx 800 ms

R-N, E/F R-N, E/FNo autorecloser


Yes No R -N FAULT, PG was advised for line patrolling.

400 KV GAYA -MAITHON - II 05.04.16 14:22 05.04.16 20:19approx 900 ms

B-N. E/F B-N. E/FNo autorecloser


Yes No B -N FAULT, PG was advised for line patrolling.

400 KV GAYA- MAITHON-I 21.04.16 14:17 21.04.16 14:47approx 720 ms

R-N , F.C- 3.37 KA, F.D- 41.6 KM

No Information ReceivedNo autorecloser


No No R-N FAULT, PG was advised for line patrolling.

400KV GAYA-MAITHON-I 26.04.16 12:08 26.04.16 12:41 800 msR-N,Zone I

Fault Distance : 40.1 KMFault current : 2.88 KA



No No R-N FAULT, PG was advised for line patrolling.

400KV BINAGURI- MALBASE 28.04.16 16:36 28.04.16 17:17 1000 ms TRIPPED, No Information ReceivedNo autorecloser


No NoTRIPPED FROM BINAGURI END ONLY (Dip in B-Ph

voltage observed). Zone 2 picked up from Binaguri but not operated. DEF operated

400KV BAHARAMPUR-BHERAMERA- I 05.04.16 16:15 05.04.16 16:41 <100B-N, Z-I, 34.29 KM from Behrampore, F/C 6KA



No No B -N FAULT

400KV BARIPADA - MENDHASAL 09.04.16 15:15 09.04.16 15:55 <100B-N,Z-I, F/C 3.75 kA, 51

Kmfrom BaripadaNo Information Received


PMU dataNo No B - N FAULT. Permanent fault

400KV BIDHANNAGAR-ARAMBAG 10.04.16 12:36 10.04.16 12:56 <100R-N, Z-I, 62.4 KM from

BidhannagarB-N, Z-I, F/C= 4.42 KA,

41.4 KM from Arambag


PMU dataNo No B - N FAULT, PLCC not in order. Will be in service

within a month

400 KV PATNA-BALIA-IV 18.04.16 21:26 18.04.16 22:44 <100 DT Received No Information ReceivedNo autorecloser


No No R-N FAULT, ER-I not available

List of important intra regional transmission lines (220 kV & above) in ER which tripped in Apr'16220kV & above Intra Region Transmission Lines

Fault clearing time is violating protection standard (As per PMU data)

No autorecloser operation observed in PMU data


RESTORATION TIME

Fault Clearance

time in msec




received within 24

Hrs


Hrs


400KV KTPP-ARAMBAGH 24.04.16 10:23 24.04.16 10:36 <100B_N fault, Z1

Fault current : 12.44 KAFault Distance : 3.157 KM

B_N fault,Z1Fault current : 4.294 KA


PMU dataNo No B-N FAULT, PLCC not available

400KV MPL- RANCHI-II 30.04.16 17:47 30.04.16 18:41 <100R-N fault

Fault Distance : 187 KMFault current : 1.6 KA



No No R-N FAULT, ER-I not available

400KV MPL- RANCHI-I 30.04.16 17:59 30.04.16 19:02 <100B-N fault

Fault Distance : 179 KMFault current : 1.8 KA



No No B-N FAULT, ER-I not available

400 KV BERHAMPUR - BHERAMARA-I 12.04.16 11:06 12.04.16 12:19 -- No Information Received No Information ReceivedFault not observed in

PMU dataNo No

MAIN BAY AT BERHAMPUR UNDER S/D 11:03HRS /12.04.16 AND TIE BAY CB HAND TRIPPED

11:06HRS/12.04.16 ON SPARKING OBSERVED IN ISOLATOR AT BERHAMPUR END.

400KV MAITHON-KAHALGAON-I 18.04.16 16:19 18.04.16 16:46 -- Not tripped DT ReceivedFault not observed in

PMU dataNo No Spurious tripping, Kahalgaon end PLCC problem.

Kahalgaon was advised to check.

400 KV PATNA-KISHANGANJ-I 19.04.16 17:08 -- DT Received O/V St-IFault not observed in

PMU dataNo No

O/V at Kishangunj (Charging attempt was taken on 22-04-16 at 11:31 hrs but tripped immediately due to DT

received at patna)

400KV BINAGURI- KISHANGANJ-I & II 22.04.16 12:33 22.04.16 13:28 -- DT RECEIVEDTRIPPED DUE TO CB

MALOPERATIONFault not observed in

PMU dataNo No

400KV BINAGURI- KISHANGANJ#2 TRIPPED DUE TO CB MALOPERATION AT KISHANGANJ END. WHILE

OPENING MAIN CB OF CKT-I AND HENCE BOTH THE LINE TRIPPED AT KSGNJ, wiring rectified.

400KV JEYPORE- BOLANGIR 22.04.16 18:04 22.04.16 18:52 O/V ST-I DT RECEIVEDFault not observed in

PMU dataNo No TRIPPED ON O/V

400KV JEYPORE- GAJUWAKA-I 22.04.16 18:16 22.04.16 20:08 No Information Received No Information Received Fault not observed in PMU data

No No

400KV JEYPORE- GAJUWAKA-I&II 22.04.16 18:16 23.04.16 16:57 No Information Received No Information ReceivedFault not observed in

PMU dataNo No

765 KV ANGUL-JHARSUGUDA-I 23.04.16 16:25 23.04.16 18:54 No Information Received No Information Received Fault not observed in PMU data

No No MALOPERATION OF LINE REACTOR AT JHARSUGUDA END, Work is in progress.

HVDC GAJUWAKA POLE-I 24.04.16 03:37 24.04.16 17:08 No Information Received No Information ReceivedFault not observed in

PMU dataNo No BUS BECAME DEAD AT GAJUWAKA

400KV JEYPORE- GAJUWAKA-II 24.04.16 03:37 24.04.16 18:16 No Information Received No Information ReceivedFault not observed in

PMU dataNo No DT RECEIVED AT JEYPORE

AT 18:16 Hrs due to failure of LA of 106 Mvar filter of Pole -I, pole got blocked at Gazuwaka due to filter

Unbalance. As One Pole got blocked power export to Gazuwaka became 200 Mw from 400 Mw and Jeypore

bus voltage raised upto 440 Kv (As Angul - bolangir was already out ,Fault level was already very low) and

Over-voltage stage -I operated again and 400 Kv Jeypore - Gazuwaka I tripped and DT send to

Gazuwaka but Breaker at Gazuwaka did not tripped and LBB operated resulted to tripping of Gazuwaka

East Bus & remaining circuit of Jeypore - Gazuwaka II and Pole tripped

Fault Not observed in PMU data


RESTORATION TIME

Fault Clearance

time in msec




received within 24

Hrs


Hrs


400KV MPL- RANCHI-I 29.04.16 16:27 29.04.16 19:21 No Information Received No Information ReceivedFault not observed in

PMU dataNo No TRIPPED ON O/V, Problem in BCU

765KV ANGUL-JHASUGUDA-I 05.04.16 04:48 05.04.16 05:22 <100 B-N, E/F, 119 km from AngulB-N, Z-1, F/C - 3.28 KA,

163.7 km from JSG

Autorecloser successful at

Jharsuguda end only.No No B-N FAULT

400KV KHARAGPUR-BARIPADA 10.04.16 13:53 10.04.16 14:17 <100B-N, Z-I, F/C= 3.21 KA, 53.88

km from KGPB-N, Z-I, F/C= 5.13 KA,

41.67 km from BaripadaAt KGP end successful No No B-N FAULT

400KV DSTPS-RAGHUNATHPUR-II 11.04.16 14:41 11.04.16 15:57 <100B_N fault,Zone I

Fault current : 4.47 KAFault Distance : 70.5 KM

B_N faultZone I

Fault current : 7.5 KAFault DIstance : 14 KM

Unsuccessful autoreclose operation observed in PMU data

No NoB-N FAULT (At 14:30 hrs, 400KV DSTPS-RTPS II tripped due to B_N fault with same relay indication while ckt-I

opened from DSTPS end only.)

400 kV TALCHER-ROURKELA- I 21.04.16 13:51 22.04.16 13:41 <100 ZONE-I,Y-PH, 39.08 KMZONE-1,Y-PH , DISTANCE- 131.8 KM, F/C -2.621 KA

AT RKL SUCCESSFUL AT TALCHER THREE

PHASE TRIPPED DUE TO Breaker auxiliary contact malfunction

Yes No Y-N FAULT

Others

Minutes - ERPC

Documents

Transcript of Minutes - ERPC