new doc 8 1wrpc.gov.in/pcm/minutes_pcm_126.pdf · 2016-05-05 · 126 pcm minutes held on 02 &...

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126PCMMinutesheldon02&03Feb2016atWRPC,MUMBAI Page1

MINUTES OF 126th PROTECTION COMMITTEE MEETING OF WRPC

HELD ON 02nd & 03rd OF FEBRUARY 2016 AT WRPC MUMBAI

The 126th meeting of Protection sub-Committee was held on 02nd & 3rd February 2016 at

WRPC Mumbai. The list of participants enclosed at Annexure – I.

Shri S D Taksande, MS, WRPC welcomed all participants to the meeting.

He stated that with the increased size of the grid and integration of many private players in

generation and transmission, difficulties are being faced by the operators to work within the

framework of regulations to achieve safe and secure operation of the grid. Recently on

14.01.2016 and 21.01.2016 the tripping of both 765kV Agra-Gwalior D/C lines was a critical

event and may have led the grid in trouble. Hon’ble CERC is keeping an eye on such events

and have came up with orders on the grid disturbances of 30th & 31st July 2012, filed Suo-

moto and imposing pecuniary fines on state and regional load dispatch centres for the first

time.Many issues such as protection audit observations etc are also being monitored by

Hon’ble CERC, therefore the orders of Hon’ble CERC needs to be complied within the

stipulated timelines. He intimated that the 125th PCM was held in June 2015 and therefore

the 126th PCM covers the occurrences between May 2015 to November 2015. These two

days would be very hectic, since the number of major occurrences covered is around 60 and

other issues regarding testing of UFRs, Ramakrishna Committee recommendations discussed

in the 4th NPC meeting are slated for discussion in this meeting. Issues such as enquiry

committee recommendations and protection audit observation compliances need to be

updated.

He requested Superintending Engineer (Protection), WRPC to take up agenda items.

ITEMNO.1: CONFIRMATION OF MINUTES OF 125th PROTECTION

COMMITTEE MEETING

SE(P) WRPC stated that the minutes of 125th PCM, held on 05.06.2015at WRPC, Mumbai

were circulated vide WRPC letter No. WRPC/Protection/125 PCM/2015/6609 dated

03.08.2015 and no comments were received from members, therefore Committee may

confirm the minutes of 125th PCM circulated vide letter dated 03.08.2015.


The minutes of 125th PCM circulated vide letter dated 03.08.2015 were confirmed

without any modifications.

ITEM 2 :OCCURANCES/GRID DISTURBANCES (Period From May 15 to Nov.15):

A. OCCURANCES IN GUJARAT SYSTEM

2.1. Occurrence on 11.06.2015 at 400/220 kV Kasor Sub-station, Gujarat – GETCO

representative stated that on11.06.2015 at 09:48 Hrs, during transferring the elements from

400 kV Bus 1 to 400 kV Bus 2 for availing planned outage of 400 kV Bus 2, the B phase

pantograph isolator on bus 2 side of 400/200 kV ICT 2 broke and came in direct contact of

ground creating a permanent bus fault. With this, the bus bar protection operated for 400

kV Bus 1 as well as Bus 2 as the bus 1 isolator was in close position (during transit period)

with both the buses. This resulted in tripping of all 400 kV elements from 400/220 kV

Kasor Sub-station. During event, there was no load/generation loss. The B –phase pento PI of bus isolator is replaced on 15/6/15. All the elements were restored by 17:00 Hrs on 11.06.2015.

Committee observed that the operation of Bus Bar protection was in order.

2.2. Occurrence on 13.06.2015 at 400/220 kV Essar Hazira Sub-station, Gujarat -

WRLDC intimated that Essar Steel load has been interrupted on 13.06.2015 June 2015 at

08:45 Hrs due to loss of 400 kV Jhanor-Hazira circuit 2.

At 08:19 Hrs , 400 kV Essar Hazira – Jhanor 1 tripped from both end on Y-B phase fault.

Instruction for line patrolling was issued due to phase to phase fault.

At 08:43 Hrs , R phase to earth fault occurred on 400 kV Essar Hazira – Jhanor 2 and

single phase trip command were issued at both end with initiation of A/R. Immediately 3

phase trip issued at Hazira end causing its tripping and loss of Hazira load. The line has

successfully reclosed from Jhanor end. The fault currents recorded at Hazira ends were

Ia=4.05kA, Ib=1.8kA & Ic=2.02kA.

During the above occurrence, total load loss of 204 MW for a period of 16 minutes

occurred. All the elements were restored by 10:39 Hrs.


Committee felt that there may have been a developing fault on other two phases of

400kV Essar Hazira-Jhanor#2, line and subsequently resulting in a 3 phase fault,

which can be seen by the fault currents recorded at Hazira end.

2.3. Occurrence on 15.06.2015 at 400/220 kV Wanakbori sub-station, Gujarat –

GETCO representative stated that on 15.06.2015 at 12:19 Hrs after the replacement of

Main Bus 1 side Isolator of 220 kV Wanakbori – Vyankatpura, the line was being charged

however the local earthing was not removed on 220 kV Bus 2 side resulting in Bus Fault

on 220 kV Bus 1 at Wanakbori S/s. This led to tripping of all connected elements from 220

kV Bus 1. During this, Wanakbori Unit 1, 2 and Unit 7 has tripped causing loss of 561

MW.

On date 15-06-2015, the 220KV Vyankatpura line outage was taken at Vyankatpura

substation for attending the insulator replacement work under R & M scheme.

The same was approved by SLDC, so 220kv Vyankatpura line was made OFF at

08:15AM. Hence switchyard maintenance-WTPS had also asked PTW NO – 59348 for

attending hot point in 89A isolator of Vyankatpura line from 08:40AM. So PTW was

issued to switchyard maintenance at 08:59AM. On physical inspection and checking, it

was found that male contact of Y phase arm of 89A isolator was melted and hence it was

utmost necessary to replace the male arm. So the work of arm replacement was started on

Vyankatpura line 89A isolator dead end side by providing local earthing on dead end side

of both 89A and 89B isolator. After replacement of arm in Y phase of 89A isolator Sr.

Electrician and his team took trial of isolator after removing the local earthing. On trial, it

was found that isolator arm was still not matching so realignment was required. The same

was done by providing earthing on dead end side of 89B isolator only at this time. After

the completion of realignment, trial of isolator 89A was taken but the local earthing

provided on dead end of 89B isolator was not removed and hence the 220KV Bus – 1

became directly earthed through 89B dead end local earthing in the trial of 89A isolator. On direct earthing of 220KV Bus – 1, Y - phase bus bar protection has operated & tripped

220 KV Dhansura – 1, 220 KV Kapadvanj - 1, ST – 1, ST – 3, ST – 4, Unit – 1, Unit – 2

& unit – 7.


All the elements were restored by 22:10 Hrs on 22.06.2015.

Committee observed that the event occurred due to insufficient caution during

scheduled maintenance. Committee recommended that concerned authorities take

note of the same and ensure that such events are not repeated.

2.4. Occurrence on 24.06.2015 at Kawas and Haldarwa Sub-station in Gujarat –

GETCO representative stated that on 24.06.2015 at 19:06 Hrs during heavy wind and rain

at Haldarwa sub-station, following damage occurred on the 220 kV Haldarwa-Zagadia bay

at Haldarwa sub station;

1. Opening of Y & B phase 220 kV CT dropper jumper toward 220 kV Bus 2

2. Opening of Y-Phase jumper towards line side

3. Y & B phase Jaw/arm of Line Isolator and 220 kV Bus 2 side isolator burnt

4. 220 kV Bus 1 and 220 kV Bus 2 side isolator jumper burnt out

5. 220 kV Bus 2 side isolator drum switch and BMK box control wiring got short-circuited.

This resulted in Bus fault on 220 kV Bus 2 at Haldarwa sub-station. However the Bus Bar

protection did not operate and all the elements connected to Bus 2 tripped on backup

protection from remote end leading blackout at Haldarwa sub-station. The 220 kV Kawas-

Haldarwa D/C sensed the fault at Kawas end in zone 2 and issued the trip command.

However, the LBB of 220 kV Kawas-Haldarwa 2 which was connected with 220 kV Bus 1

at Kawas end operated and all elements connected to 220 kV Kawas Bus 1 tripped.

He further informed that the contingencies occurred due to inclement weather conditions.

On detailed investigation Alstom make Bus bar protection Scheme did not operate.

Further, the dropper connection of Y-ph CT (P1 & P2 side) and B-ph CT (P1 Side) of 220

KV Zagadiya line got disconnected from fire wage due to heavy wind pressure and rainy

weather. Heavy spark marks were observed in MK box of 220 KV Zaghadia line and fault

was extended up to PU installed in bus bar panel because of poor earthing and PU (P743)

of 220 KV Zaghadiya line became faulty. The fault was in bus zone-2 and bus bar

protection should have clear the fault. The bus bar scheme did not operate and hence all

220 KV lines got tripped in Zone-2 from remote end except GPEC-1 & 2 and IPCL 1 & 2.

The 220KV GPEC-1 & 2 tripped in Zone-1 from remote end where as 220 KV IPCL 1 &2

were tripped on under voltage. All 220 KV lines/transformers breaker were hand tripped at


220 KV Haldarwa substation after tripping from opposite end due to this 220 KV

Haldarwa became dark.

The Faulty PU of 220 KV Zaghadia line was replaced by available spare PU and taken in

service. The matter of non operation of bus bar scheme was intimated to the Alstom with

relevant information and the scheme shall be thoroughly tested in presence of Alstom

Engineer. GPEC and IPCL have also been intimated to review the settings at their end and

test the scheme as the lines tripped in zone-1 and under voltage respectively at their end.

Most of the elements were restored by 23:34 Hrs on 24.06.2015. Few elements were

restored on 25.06.2015 and 220 kV Haldarwa-Zagadia was restored on 30.06.2015. Status

of Kawas ST 1 not available.

The load loss was of the order of180 MW in Gujarat system as per WRLDC SCADA.

Committee felt that the failure of operation of Bus bar protection was undesirable.

The trippings from remote ends in Zone 2 due to non operation of Bus bar protection

was in order. However the tripping of 220KV GPEC-1 & 2 in Zone-1 and 220kV

IPCL 1 & 2 on overvoltage is undesirable and the settings be reviewed. Further

operation of LBB of 220 kV Kawas-Haldarwa 2 at Kawas needs to be investigated.

Committee suggested to check the earthing system, panel earthing and measurement

of earth resistance.

2.5. Occurrence on 06.07.2015 at Akrimota sub-station, Gujarat - WRLDC vide

letter no. WRLDC/MO-3/1658/2015/1111 dated 23.09.2015 intimated thaton 06.07.2015 at

11:13 Hrs, due to Bus fault at Akrimota sub-station, its bus bar protection operated and

tripped both the 220 kV Bus causing tripping of all the elements. This has resulted in loss

of 125 MW generation at Akrimota and 100 MW load loss in the Akrimota, Jamanwada

and Panadero area.

Most of the elements were restored by 19:52 Hrs. No details were available for 220 kV

Akrimota-Jamanwada line. Report received from WRLDC is enclosed at Annexure – 2.5.

There was no representation from GSECL for the PCM, therefore the occurrence could be

analyzed.

Committee opined that a detailed report may be submitted by GSECL.

2.6. Multiple Line tripping and Loss of Load in Gujarat on 21.07.2015 and

22.07.2015 - WRLDC vide letter no. WRLDC/MO-3/1658/2015/1641 dated 18.11.2015


intimated that the inclement weather on 21-July-15 has led to multiple line tripping and the

load crash in Gujarat State. The effect of bad weather has started to impact the Gujarat

Power System from 13:00 hrs of 21-July-15 and max demand crash compare to previous

day was reported at 4 am on 22-July of 2800MW. There was multiple tripping during this

bad weather, 23 lines of 400kV tripped. As reported by Gujarat there were 31 number of

lines of 220kV tripped. Further, there was Bus Fault at following stations

a) 400 kV Kosamba Bus fault on BUS-II at 3:23 hrs leading to tripping of 400kV

Kosamba-Ukai-II and 400 kV Kosamba-Chorania-I rest of the feeder remain connected

through BUS-1.

b) 400 kV EssarVadinar 400 kV Bus 2 bus bar protection operated at 02:28 Hrs. No

element tripped as 1 1/2 Bus bar scheme.

c) 400 kV Amreli (GETCO) BUS fault on both the 400kV BUS at 6:21 hrs. All the three

400kV Line and three 400/220kV ICTs tripped at 400kV Amreli S/s. This has resulted in

loss of load at Dhasa area.

d) 220 kV Bus fault at Dahej Sub-station at 03:13 Hrs. All elements got tripped. Y phase

flyover Bus conductor of 220/100 kV ICT 1 from 220 kV side broken.

Most of the elements were restored by 20:21 Hrs on 22.07.2015. Nagda-Dehgam-II, Jetpur

ICT I, Kosambaukai-III, Amreli ICT-2 were restored on 23.07.2015. Dhule-Sardar

Sarovar-I, Amreli- Jetpur-II restored on 24.07.2015 and SSP-Rajgarh-I was restored on

25.07.2015.

Committee felt that trippings were due to inclement weather conditions.

2.7. Occurrence on 22.07.2015 at 400/220 kV Amreli S/s, Gujarat – GETCO

representative stated thaton 22.07.2015 due to transient Y phase fault at 06:11 Hrs. on the

400 kV Bus 1 of 400/220 kV Amreli sub-station, it’s 400 kV bus bar protection operated

for bus zone-1 resulting in loss of all 400 kV Bus 1 connected elements along with the bus

coupler. While at 6:19 hrs the bus bar protection operated for 400 kV bus zone 2 due to R

phase fault resulting in tripping of remaining 400 kV elements from Amreli Sub-station.

At 3.50 hrs., as per LDC instruction 400 KV Amreli-Jetpur line-1 breaker was made OFF

from Amreli end due to overvoltage, which was connected on 400 KV Bus-2.

At 6:11 hrs, numerical bus bar protection operated in bus zone-1. So, all 400 KV bays

connected to 400 KV bus-1 got tripped along with 400 KV bus-coupler. Bus zone-1


operated may be due to transient flash over on the bay. Hence all the lines connected to

bus-1 tripped.

The 400kV Amreli-Hadala, Amreli-Jetpur line-1 (due to over voltage breaker OFF) and

400/220 KV 315MVA ICT-1 & 2 connected to 400 KV bus-2 survived.

At 6:19 hrs. numerical bus bar protection operated in bus zone 2. 400KV Amreli-Hadala

Line, 400/220kV 315MVA ICT-1 & 2 got tripped on R-ph fault BZ2. This was due to

flashover at fly-over bus of ICT-2, pilot string of R-ph which got broke and the jumper

felldown on ground

Most of the elements were restored by 09:18 Hrs on 22.07.2015. 400/220 kV 315 MVA

ICT-2 was restored on 23-07-15 at 18:50 Hrs and 400 kV Amreli-Jetpur 2 was restored on

24-07-15 at 17:20 Hrs.

Committee observed that the operation of Bus Zone 2 protection was in order and

operation of Bus Zone 1 might have been due to transient Bus fault due to inclement

weather.

2.8. Occurrence on 22.07.2015 at 220 kV Dahej S/s, Gujarat - WRLDC intimated

thaton 22.07.2015 at 03:12 Hrs, Y Phase flyover insulator string of 220/66 kV, 100 MVA

ICT 1 bay flashed over and its conductor fell down on 220 kV Bus A & Bus B in at 220 kV

Dahej Sub-station. The fallen conductor was in such way that it was touching all three

phases of 220 kV Bus No 2 and only B phase of 220 kV Bus 1 causing Bus fault on both

the buses. This has resulted in Bus bar protection operation at 220 kV Dahej sub-station

causing loss of 220 kV causing its loss of supply.

Y-ph flyover insulator string of 220/66KV, 100 MVA TR-1 bay found flashed over and

conductor fell down on 220 KV Bus A & Bus B in such a way that touching all three

phases of bus No 2 and only B phase of Bus 1 which had caused operation of bus bar

protection scheme. The operation of Alstom makes numerical Bus bar protection scheme

type P741 /P743 is in order. Due to tripping of all elements on both the bus.

Flashed insulator string was with antifog insulator. Same was replaced by SRI on war

footing base.

The substation is commissioned in 1998 and substation is situated in saline area and

chemical industrial polluted zone.


Most of the elements were restored by 15:40 Hrs. Status of 220/66 kV, 100 MVA ICT 3

not available. No details have been received from SLDC Gujarat on the load

loss/generation loss during the event. From the demand plot of Gujarat, Load loss of 163

MW is observed during the event as supply has tripped. Energy unserved is in tune of 1339

MWHrs.

Committee felt that failure of flyover insulator string may be due to exposure to

polluted and saline atmosphere and recommended that SRI should be provided at

such S/Ss. The operation of Bus bar protection was in order.

2.9. Occurrence on 26.07.2015 at Tripping of HVDC Mundra-Mohindergarh

Bipole- APL representative stated that HVDC Mundra-Mohindergarh both poles tripped at

22:26 Hrson 26.07.2015 due to tripping of 12/24 A type filter banks at Mohidergarh end.

With the tripping of HVDC bipoles, Generation backdown SPS at Mundra operated

causing tripping of Unit 8 & 9 and runback of Unit 7. While in Northern region, SPS has

led to loss of load for this contingency. However along with HVDC Mundra –Mohidergarh

SPS, 765 kV Gwalior-Agra SPS for line loading crossing 1400 MW on each circuit has

also operated.

He further informed that the grid condition was such that the filter actually discharged

through the fault. The impedance condition was such that only the base filter could find

low impedance path and therefore all the base filters tripped. It may be noted that the other

type of filters did not trip which indicates that the tripping is strongly related to the specific

grid conditions and impedances, which made it easy for discharge of only base filters and

not others. The actual current in the reactors of these filter shows too high current which

justifies tripping of the filters. The fact that the current in filter reactor increased even

when the bus voltage of R&Y had actually fallen further supports this assumption of

specific low impedance case for base filters.

Generation loss during the event was 1090 MW in Western region and the net load loss in

the Northern region was around 1160 MW during the event.

Committee observed that the system conditions arisen during the fault was a rare one

and needs to be analysed in depth. Since the occurrence took place in NR, the


details/analysis be shared by APL in the next PCM, on receipt of the same from

NRLDC/NRPC.

2.10. Occurrence on 13.11.2015 at Ranasan resulting in islanding of Ahmedabad –

AMGEN representative stated that on 13.11.2015 at 13:42 Hrs, B phase pole of 220 kV

Ranasan-Karamsad circuit 1 at Ranasan end , tripped within 60 ms and again reclosed after

a definite period of 800 ms, but line again tripped due to persistent fault. It took more than

300 ms to clear the fault. 220 kV Dehgam-Ranansan 1 & 2 tripped from Dehgam end in

zone 2 and 132 kV TPL Sabarmati-Sabarmati GETCO D/C tripped on high set directional

earth fault protection from TPL end. The loss of 132 kV TPL Sabarmati-Sabarmati

GETCO D/C resulted in islanding of Sabarmati and Ahmedabad as per the design.

Ahmedabad city is having an islanding scheme with AEGEN( AE Co) generation. The

Islanding frequency is 48.5 Hz & 0.5 Hz / sec or 47.8 Hz & 0.15 second the Islanding

operation is with opening of 132 kV TPL Sabarmati– Sabarmati GETCO D/C. So with the

tripping of 132 kV TPL Sabarmati– Sabarmati GETCO D/C, the Ahmedabad-Sabarmati

system got islanded with the system.

The running units were D (120 MW) and E (121 MW) which were running at their

technical minimum i.e. 68 MW and 75 MW respectively. Load in the island was in tune of

264 MW.

The delayed tripping of Karamsad line caused both 220 kV GETCO Ranasan-PGCIL lines

to trip on Distance protection Zone-2 and TPL-GETCO (SBI) tie lines tripped on

directional earth fault (high set). The protection system operated as per adopted setting &

nature of fault. TPL-SBI System Islanded at 13:42:56 with D&E stations in operation. PLC

operated for load relief of 119.5 MW as per the logics against requirements of 121 MW.

The demand in the islanded system was only 135 MW with a power frequency index of

less than 2.5 MW / Hz. As the units were operating at Technical Minimum level, this major

and abrupt frequency variations lead to variations in operating parameters of the plant.

Turbine speed increased to 3100 rpm at 13:46:01. Turbine Protection Accelerator Relay

(AR) operated at E station and the turbine speed was controlled.

Again turbine speed increased to 3100 rpm at 13:46:15 and AR relay operated at E station.

The situation persisted for 4 seconds, leading to tripping of E station on Reheater

Protection at 13:46:19.


Loss of generation occurred resulting in fall in frequency. PLC operated but there was no

load relief available as per the PLC configuration. D station tripped on under frequency at

13:46:25. Thus total power failure occurred at AMGEN.

In 3 events out of 5 Islanding events occurred in past, the island survived. The PLC

Islanding scheme operation was perfect on both occasions and hence need not require

any correction.

Relay settings were thoroughly checked and definite time setting of 132 kV TPL

Sabarmati– Sabarmati GETCO D/C which was earlier set at 300msecs has now been

revised to 400msecs at Ahmedabad end. The auto reclose of 220kV Ranasan Karamsad

Ckt-1 TOR which was earlier disabled has now been enabled.

The sub-station auxiliary supply was restored and by 14:51 hrs the TPL Sabarmati station

was connected with Sabarmati GETCO by charging of the 132 kV TPL Sabarmati–

Sabarmati GETCO D/C. After this 220 kV Dehgam-Ranansan 1 & 2 were taken in service

at 15:07 and 15:08 respectively. At 17:11 Hrs AMGEN unit D and at 17:41 Hrs Unit E

were synchronised.

The load loss of 264 MW and Generation loss of 143 MW occurred with collapse of

islanded system.

Committee felt that the corrective actions taken by AMGEN as regards to relay

settings are in order. Further, Committee suggested that AMGEN may review the

Islanding scheme by taking care of the availability of generation in the island i.e. in

case the generation in the island is at technical minimum or low the preparedness of

load shedding quantum should be precise, so that the load generation balance in the

island is exactly matched, since during such circumstances any unbalance in the load

generation may lead to unstable operation of the generators in the island.

B. OCCURANCES IN MADHYA PRADESH SYSTEM

2.11. Occurrence on 05.05.2015 at 220kV S/s Pithampur : MPPTCL representative

stated that on 05.05.2015 at 17:04 Hrs, B-phase CT of 132kV Transfer Bus Coupler burst

(through which load of 132kV Pithampur-Bridge Stone feeder was being fed)and 220kV

Main Bus-I failed. Consequently all connected feeders & transformers of 220kV Main

Bus-I & 132kV Bus tripped.


Simultanously PT fuses of 220 kV Bus I also failed. There by tripping 132 kV Int.cont.-I

and II from 132 kv S/S, 160 MVA X-mer I on Buchh indication, 132 KV incoming of 160

MVA X-mer – II on E/F indication, 220 KV Pithampur–Rajgarh-I, BC–N,Z-I, Remote end

DT recd, 220 KV int.cont.-II from 220 KV S/S PTH end only, A-N,Z-I

These trippings resulted in to failure of 132 KV supply at 220 KV S/s Pithampur, 132 KV

S/s Jamli, 132 KV S/s Betma, 132 KV S/s Bagdi, 132 KV Parasrampuriya (Industrial

Feeder), 132 KV Bridge Stone (Industrial Feeder) & 132 KV Hindustan Motors (Industrial

Feeder) for about 25 minutes. It was intimated by MPPTCL that 220kV Bus PTs are wired

up for the DPS of lines.

All the elements were restored by 20:05 Hrs.

Committee observed that the tripping of elements on backup protection, in absence of

Bus bar protection were in order and recommended that bus bar protection should be

provided on 132kV bus. The tripping of 220 KV Pithampur–Rajgarh-I & 220 KV

int.cont.-II was undesirable and recommended that line PTs should be provided and

used for DPS instead of Bus PTs..

2.12. Occurrence on 06.05.2015 at 220kV S/s Julwania : MPPTCL representative

stated that on 06.05.2015 at 02:05 Hrs, 132kV, Y-phase CT of 132/33kV,20MVA X’mer-

II burst creating 132kV Bus fault at 220kV S/s Julwaniya. This resulted in failure of 132kV

supply at 220kV S/s Julwaniya, 132kV S/s Sendhwa, 132kV Pansemal and 132kV S/s

Anjad. During this event the total load loss was approx.. 53.6MW, 25.6MWH and the

duration of outage was approx.30 minutes.


Committee observed that the tripping of elements on backup protection, in

absence of Bus bar protection were in order and recommended that bus bar

protection should be provided on 132kV bus.

2.13. Occurrence on 08.05.2015 at 220kV S/s Sarni : MPPTCL representative stated

that on 08.05.2015 at 14:01 Hrs, B-phase conductor of 132kV S/s Sarni broke and snapped

creating 132kV Bus fault at 220kV Sarni. 220kV Sarni-STPS-I & II tripped from STPS

end on jerk. Due to 132kV Bus Fault, 132kV supply at 220kV S/s Sarni failed. During this

event there was load loss of about 35 MWH during the above tripping.



Committee observed that the tripping of elements on backup protection, in

absence of Bus bar protection were in order and recommended that bus bar

protection should be provided on 132kV bus. Further tripping of 220kV Sarni-

STPS-I & II tripped from STPS end was undesirable and the relays/settings at

STPS end needs to be checked.

2.14. Grid Occurrence on 19.05.15at Madhya Pradesh: WRLDC representative stated

that on 19th May due to thunderstorm and rain, Northern Grid demand started reducing

from the afternoon (13:30 Hrs) . A load crash of around 9450 MW occurred in the state of

Haryana, Rajasthan, Uttar Pradesh, Delhi and Chandigarh by 18:06 Hrs. various lines/ICTs

have tripped in the Northern region during the period. The thunderstorm also hit the upper

eastern part of the Madhya Pradesh by 16:00 Hrs. Events Summary:

• 16:18 Hrs: 765 kV Gwalior-Agra 1 & 2 tripped on R Phase to earth fault. Due to this

220 kV Gwalior-Malanpur 1 & 2 also tripped as per the intertrip scheme.

• At 16:26 Hrs: 400/220 kV 315 MVA ICT 2 at 400 kV Bina (MP) S/s tripped on B

Phase differential protection operation.

• At 17:07 Hrs: 132 kV Malanpur – Mehgaon Circuit tripped. This was followed by

tripping of 220 kV Malanpur-Mehgaon, 220 kV Mehgaon-Auraiya and 220 kV

Malanpur-Auraiya. This led to blackout at Mehgaon S/s.

• At 18:03 Hrs. 220/132 kV, 160 MVA ICT 2 at Sabalgarh sub-station tripped on over-

flux indication. Due to high voltage, 220 kV Sabalgarh – Shivpuri 1 was opened at

18:20 Hrs (220 kV voltage was around 242 kV). As the high voltage scenario still

persisted, 220 kV Shivpuri – Bina (MP) Circuit was opened at 18:40 Hrs. This led to

shifting of complete load of 220 kV Shivpuri and Sabalgarh S/s on 220 kV Bina (PG) -

Shivpuri circuit and 132 kV Shivpuri- Pichhore circuit.

• At 19:27 Hrs, 220 kV Bina (PG) - Shivpuri circuit tripped on fault leading to transfer of

complete load on 132 kV Shivpuri- Pichhore which would also have tripped resulting

in loss of 220/132 kV Shivpuri and radial connected 220/132 kV Sabalgarh and other

132 kV stations.

• At 19:07 Hrs 765 kV Satna-Gwalior 2 tripped which was taken in to service at 19:31

hrs.

• Again, the 765 kV Satna-Gwalior 2 tripped at 19:32 hrs, which was followed, by other

tripping from Gwalior (PG), Bina (PG), and Bina (MP) stations.


• Between 20:08-20:14 Hrs, 765 kV Satna-Bina 2, 400 kV Bina-Sujalpur D/C, 400 kV

Bina (MP)-Bhopal 2 and 765 kV Bina-Indore S/C tripped on faults.

Most of the elements were restored by 22:44 Hrs on 19.05.15 and few other lines were

restored on 20.05.15, 21.05.15,01.06.15 and 765 kV Satna-Bina 2 line was restored on

31.05.15 due to tower collapse.

Committee observed that most of the trippings were due to inclement weather.

2.15. Occurrence on 11.06.2015 at 765/400 kV Bhopal-BDTCL Sub-station –

WRLDC representative stated that on11.06.2015 at 17:20 Hrs, heavy rain, thunder with

lightning accompanied by strong winds prevailed in the Bhopal (BDTCL) substation.

There were two incidence of flashovers observed within 2-minute span in the station. First

incident occurred at 17:20 hrs on Y-phase of 765/400 kV ICT-2 HV bushing that was

accompanied by discharge (to earth) across every LA connected to entire inter-connected

Y-phase. This led to tripping of ICT-2 on differential protection operation. While the

second flashover occurred at 17:22 hrs on R-phase of 765/400 kV ICT-1 HV bushing. In

addition, 765 kV Jabalpur-Bhopal line also tripped at 17:20 hrs on Zone-4 fault in Y-phase.

During event, there was no generation and load loss.


Committee observed that most of the trippings were due to inclement weather.

2.16. Occurrence on 16.06.2015 & 17.06.2015 at JP Nigrie-Satna 1 circuit-WRLDC

representative stated that on 16th June 2015, 400 kV JP Nigrie-Satna 1 circuit tripped on R

Phase to earth fault(other circuit was out on planned shutdown) causing loss of evacuation

of JP Nigrie and tripping of Unit 1 and 2. A/R was attempted, however due to persisting

fault the line tripped. 400 kV JP Nigrie-Satna 2 was out on planned outage since 12th June

2014 for Railway crossing work. This led to loss of 1137 MW of generation.

On 17th June 2015, 400 kV JP Nigrie-Satna 1 tripped on receipt of DT from Satna

end leading to loss of evacuation of JP Nigrie causing tripping of Unit 1 and 2. This led to

generation loss of 792 MW. As per information received from PGCIL, the line tripped on

overvoltageprotectionoperationonSatnaendandsendDTtoremoteend.FromWRLDCSCADA


data,itwasfoundthatvoltageofSatna400kVBuswas413kVduringthetrippingperiod,which

indicatethattheprotectionoperationatSatnaendwasnotdesirable.


Committee requested PGCIL and JP Nigrie to check the over voltage settings of the

relays and the CVT circuit.

2.17. Occurrence on 23.06.2015 at 220/132 kV Itarsi Sub-station, Madhya Pradesh –

MPPTCL representative stated thaton 23.06.2015 at 00:16 Hrs, due to falling of ‘B’- Phase

conductor of 220 kV Itarsi – Sarni 2 circuit from gantry on 220 kV Main Bus – I & II at

220/132 kV Itarsi Sub-station, Bus fault created at the substation.

The bus bar protection has not operated as it was kept out of service and the lines/ICT

tripped on backup protection. The 160 MVA Xmer, 3×40 MVA Xmer at 220 Kv

Itarsi, and 220 kv Itarsi-Pipariya Ckt-I&II, 220 kv Itarsi- Handiya Ckt –I& II, 220 kv

Itarsi- Barwah ckt., 220 kv Itarsi- Hoshangabad ckt., 220 kv Itarsi- Itarsi (PGCIL)

ckt, 220 kv Itarsi- Sarni ckt-II,III &IV, 132 kv Itarsi- Hoshangabad ckt-I & II, 132 kv

Itarsi- Pipariya ckt, 132 kv Itarsi- Seoni Malwa ckt & 132 kv Seoni Malwa- Harda ckt

from remote ends.

This has led to blackout of 220/132 kV Itarsi and 132 kV Seoni-Malwa Substation and load

loss of 25 MW. The newly commissioned GE make Bus bar protection at the sub-station

was kept in only alarm mode, which has led to delayed fault clearance. The nature of fault

was three phase fault. In addition, the severity of three phase fault was such that the

voltage of 400 kV Itarsi bus dipped by around 100 kV for this duration.


Committee observed that tripping of 132kV lines from remote ends ahead of 132kV

side of ICT was undesirable and recommended that the relay co ordination of 132kV

lines should be done with the ICT132kV side protection. The 132kV side ICT DMT

settings should be set between the Z-2 & Z-3 timings of the 132kV lines.


2.18. Occurrence on 30.06.2015 at 400kV S/s Indore – MPPTCL representative stated

thaton 30.06.2015 at 18:39 Hrs., 220kV side LBB of 400/220kV, 315 MVA ICT-I

operated. The core of CT used for LBB initiation was earthed due to cable damage. The

LBB protection in turn initiated the operation of Bus Bas Protection of 220kV Main Bus-I

at 400kV S/s Indore. There was no load loss due to above tripping.


Committee felt that megerring of CT cables should be done during the routine

maintenance of the CTs.

2.19. Occurrence on 02.07.2015 at 220 kV Sujalpur Sub-station in Madhya Pradesh

MPPTCL representative stated that that on 02.07.2015 at 16:15 Hrs. during testing and

checking of control panel of 220/132 kV, 160 MVA ICT II at 220 kV Shujalpur S/s, the

LBB protection of 220/132 kV, 160 MVA ICT III got operated which initiated the

operation of 220 kV Bus Bar Protection at 220 kV Shujalpur S/s. This led to tripping of all

the elements connected to the 220 kV Sujalpur station.

While testing & checking of control & relay panel of 220/132KV,160MVA T/F II, the

LBB contact of 160MVA T/F –III LBB initiation relay got shorted (defective contact)

resulting in mal operation of LBB protection. The defective LBB initiation relay has been

replaced & scheme again taken into service.

However the 132 kV Networks remained connected and there was no interruption to

supply during the event. During the event there was no load/generation loss.


Committee observed that care should be taken during carrying out testing work.

2.20. Occurrence on 20.07.2015 at 400/220 kV Bina (MP) sub-station – MPPPTCL

representative stated that on 20.07.2015 at 13:05Hrs, R Phase lightening arrester of 220

kV Bina-Bina I/C -1 got damaged due to lightening, however the fault was not cleared

from Bina end ( 400/220 kV Bina MP Substation) as its breaker did not trip even after

relay has given the trip command. This resulted in continuous fault feeding by the 220 kV


Bus 2 of 400/220 kV Bina (MP) sub-station and causing tripping of all elements from 220

kV Bus 2 on backup protection/remote end protection. This resulted in dead 220 kV Bus 2

at Bina Sub-station.

Although DPR of IC-I at 400 KV S/S has sensed the fault correctly, the non tripping of CB

was due to wrong position of TBC NIT on “Transfer” position instead of keeping it on

“Normal” position, which resulted in to blocking of trip command to CB.

Further, LBB operation was also blocked due to removal of LBB fuse links in Relay panel

of IC-I feeder. T/F-III tripped on DTOC indication and took about 200 msec. T/F- II

tripped on E/F took about 770 msec. to clear the fault.

The Back Up Relay setting of Bus Tie has been reduced to 0.18 TL. Further the above

incident has occurred due to lightening on line at S/S where earth shielding wire was not

provided on the line at 400 KV S/S end , The same has been provided on dtd.20-05-2015.

There was no interruption of any generation/load due to this event.

Committee observed that tripping of lines/elements from remote ends was in order,

due to stuck breaker situation and LBB was out of service. The LBB protection

should be always in circuit so that the fault is at least cleared in the LBB timings.

Further operating staff should be instructed to check the NIT switch positions after

every transfer operation.

2.21. Occurrence on 25.07.2015 at Itarsi Sub-station – MPPTCL representative stated

that on 25.07.2015 at 11:05 Hrs, 400 kV Bus 1 at Itarsi along with 400 kV Bus reactor 1,

Bus Reactor 3 and 400 kV Jabalpur-Itarsi 1 circuit tripped during NTAMC work on the

Main Bay of Bus reactor 1 which is connected on 400 kV Bus 1. The DRs triggered due to

tripping of CB were also checked and no signs of fault currents was observed. Outages was

taken on 26.07.2015 on Bus 1 to ascertain the reason for tripping. However nothing

abnormal was observed.

There was no interruption of generation or load during the event.



Committee felt that inadvertent initiation of trip signal during NTAMC work might

have occurred and suggested that had proper care been taken during the NTAMC

works the disturbance would have been avoided.

2.22. Occurrence on 18.08.2015 at 220/132 kV Malanpur sub-station- WRLDC vide

letter no. WRLDC/MO-3/1658/2015/1573 dated 03.11.2015 intimated that on 18.08.2015

at 17:21 Hrs, B phase CT of 220 kV Gwalior-Malanpur 2 circuit burst at Malanpur end

creating bus fault on 220 kV Bus at Malanpur end. This led to Bus fault on 220 kV bus of

Malanpur causing operation of Bus bar protection and loss of all 220 kV elements. With

this, the load got shifted to 132 kV lines were also lines tripped causing interruption of

supply at 220/132 kV Malanpur sub-station.

At 220 kV S/s Malanpur, Bus arrangement is 1 Main + 1 Aux. The 132 kV Banmore ckt-I

& II were on radial mode. Due to absence of supply from 220 kV side, the load got shifted

to 132 kV Mehgaon feeder. This resulted in tripping of 132 kV Mehgaon feeder on

overloading condition. Hence, total supply interruption at 220 kV S/s, Malanpur occurred.

This led to load loss of 140 MW.


Committee felt that the operation of Bus Bar protection due to failure of CT of 220

kV Gwalior-Malanpur 2, was in order.

2.23. Occurrence on 20.08.2015 at 220 kV Satna, Chattarpur, Kotar and Maihar

Sub-station – MPPTCL representative stated that on 20.08.2015 at 19:01 Hrs., R Phase

conductor of 220 kV Satna – Satna ( PGCIL) Ckt – II broke in between bottom of wave-

trap & high bus creating 220 kV Main Bus 1 fault at 220/132 kV Satna S/s. Due to non-

operation of bus bar protection for Bus 1 at the Satna sub-station, all the elements (

220/132 kV BHEL ICT , 220 kV Satna-Tons , 220 kV Satna-Chattarpur and 220 kV Satna-

Satna(PG) 2) tripped from remote end on E/F indication along with 220 kV Bus tie, thus

making dead 220 kV Bus 1 at 220 kV Satna S/s. During this the 220 kV Kotar-Tons circuit

also tripped causing loss of supply to 220 kV Kotar S/s and connected load. Due to this the

load of Chattarpur got shifted on 132 kV Chattarpur-Bijawarckt which tripped on over

current protection causing loss of supply at 220/132 kV Chattarpur. Further, the 132 kV l


load of Satna got shifted d on other ICT connected on 220 kV Bus 2 causing its tripping on

Over current. This led to shifting of 132 kV Satna load on Maihar sub-station through its

220/132 kV ICT via 132 kV Satna-Maiharckt. With this 220/132 kV ICT at Maihar also

tripped on over current which shifted the 132 kV load of Satna, Maihar on 132 kV

Keymore-Maihar circuit and it also tripped on over current protection. With this load of

Satna, Maihar was lost from the grid. During the event total load of 366 MW was lost

causing 198 MWHr energy unserved in the area.

The conductor opened and remained in hung condition without touching any structure or

earthed part, creating a highly resistive fault. Hence, none of the Distance Protection

Relays at MPPTCL end as well as PGCIL end operated in any Zone. The tripping took

place in E/F. The setting of (O/C + E/F) relay of 220 kV Bus Tie has been revised. A

highset relay is also being installed at 220 kV Bus Tie.


Committee felt that since breaker trip is not wired up for DR triggering, no DR on

the tripped lines was triggered and therefore there was no way to ascertain the nature

of the fault. Committee therefore recommended that breaker trip should be used to

trigger the DR, so that all the DRs of trippings are captured.

2.24. Occurrence on 02.09.2015 at 400/220 kV Indore (MP) Sub-station – MPPTCL

representative stated that on 02.09.2015 at 15:25 Hrs, due to LBB initiation of 220 kV

Indore-Jetpura 2 circuit which was on 220 kV Bus 2, all elements connected to 220 kV

Bus 2 at 400/220 kV Indore S/s tripped. There was no load/generation loss during the event

and no interruption in any of the area.

The LBB initiation occurred while doing SOE connection work of the SCADA system.


Committee observed that the disturbance took place due to human error and

therefore suggested that at most care should be taken during working in relay panels.


2.25. Occurrence on 03.09.2015 at 220/132 kV Mahalgaon- MPPTCL representative

stated that on 03.09.2015 at 20:37 Hrs, due to snapping of R phase jumper of 220 kV Bus

at Mahalgaon, resulting in a Bus fault on 220 kV Bus.

Prior to the event, replacement of Module in Busbar Relay was carried by M/s GE. Hence,

the relay was kept under observation only in ALARM mode, at the advice of M/s GE.

Since the Bus bar protection was kept in Alarm mode, all 220 feeders tripped from remote

end.

With this blackout occurred at 220/132 kV Mahalgaon sub-station and load loss of around

312 MW has occurred in the area. The other affected station were Motijheel and Tigra.

During the event Load loss in tune of 314 MW has occurred.

Most of the elements were restored by 01:04 Hrs on 04.09.2015.

Committee observed that tripping of all the elements from remote end in the event of

Bus Bar protection in Alarm mode was in order.

2.26. Occurrence on 09.09.2015 at 400/220 kV Indore & 220/132 kV Indore East –

MPPTCL representative stated that on 09.09.2015 at13:07Hrs due to Human error the earth

rod of R phase Isolator of Main CB of 220 kV Indore- Pitampur circuit remained in close

condition at Indore end prior to the charging of the circuit after completion of work. With

the charging of the line, short circuit occurred on 220 kV Bus 2 at 400/220 kV Indore sub-

station causing bus fault. However, the same was not cleared by the bus bar protection of

220 kV Bus 2 causing tripping of all 220 kV elements from Bus 1 & 2 on backup/remote

end protection. During this 220 kV Indore East-Dewas circuit tripped causing blackout at

220 kV Indore East Sub-station.

As the complete load of 220/132 kV Indore South Zone was being now managed through

132 kV links which due to lack of load trimming scheme got overloaded. Hence, 132 kV

Indore South Zone – Balwada and 132 kV Simrol-Barwaha circuit tripped on overloading.

This led to overloading of 132/33 kV 40 MVA ICT at Balwada which tripped on

overcurrent causing loss of load from 132 kV Balwada S/s.

The Bus-Bar protection scheme was kept out because of frequent change over(from main

to transfer Bus) work on that day, Pithampur fdr was fed through TBC. Hence the Bus

fault was cleared from remote end trippings of the fdrs . Non operation of O/C & E/F

protection of 220 kv Bus Coupler – Because its setting is provided as backup to Zone-II, as

all the fdrs tripped in Zone-II from remote end.


At around 13:14 Hrs, 220 kV Itarsi-Handia 1 circuit tripped on B phase to earth fault.

However, the stuck breaker condition occurred at 220/132 kV Handia sub-station resulting

in its LBB operation causing tripping of all 220 kV elements. There was no interruption as

load continued to feed through 132 kV system at Handia station.Load loss occurred in tune

of 53 MW at Indore East and 40 MW at Balwada. So total load loss was 93 MW. Energy

unserved quantum was 32.5 MWHr during the event.

Most of the elements were restored by 18:08 Hrs.

Committee observed that the Bus Bar protection should not have been kept out

during change over operation and recommended that the operating staff be suitably

instructed.

2.27. Occurrence on 23.09.2015 at 400/220 kV Astha Sub-station, Madhya Pradesh –

MPPTCL representative stated that on 23.09.2015 at06:37 Hrs, R Phase PT of 220 kV Bus

2 of 400/220 kV Astha S/s burst creating Bus fault on 220 kV Bus 1. This resulted in

tripping of 220 kV Bus 1 elements from Astha S/s. However the winding of failed PT hit

the Main CB of 220 kV Astha-Devas 2 circuit (on 220 kV bus 2) and damaged it, resulting

in earthing of its lower terminal. This led to 220 kV Main Bus 2 fault at Astha S/s.

Both 220 kV Satna-Birsinghpur feeder and 220 kV Satna-Rewa feeder were on Auxilliary

Bus i.e, Birsinghpur & Rewa were connected externally through auxilliary bus of 220 kV

S/s Satna.

All the 220 kV feeders tripped from remote end/backup protection. This resulted in

interruption at 400/220 kV Astha S/s, 132 kV Astha, 132 kV Ichhawar, 132 kV Polaykala,

132 kV Kannod and 132 kV SEL S/s.

During the event, load loss of in tune of 60 MW occurred.

The 220 kV Busbar Relay was on ALARM mode due to shifting and commissioning of

new feeders for stability check.

Presently, it has been taken into service.

The failed ‘R’- Phase PT was replaced and new PT taken in service at 19:20 Hrs. on

28.09.2015.



Committee observed that tripping of elements from remote end was in order, since

the Bus bar protection was kept in Alarm mode.

2.28. Occurrence on 06.10.2015 at 220/132 KV Satna S/s, MP –MPPTCL

representative stated that on 06.10.2015 at 11:04 Hrs, due to failure of R phase auxiliary

bus side post insulator of 220 KV Satna (PG)-Satna (MP) 2 at 220 KV Satna (MP)’ all

elements tripped from remote ends, since the Bus Bar protection was out of service. This

has caused blackout at 220/132 KV Satna and nearby radial connected station. During the

event, load loss of 218 MW was reported by MP SLDC. Energy unserved during the event

was in tune of 318.8 MWHr.

Both the 220 kV Satna-Birsinghpur and 220 kV Satna-Rewa feeders were on Auxilliary

Bus i.e, Birsinghpur & Rewa were connected externally through auxilliary bus of 220 kV

S/s Satna. Since, there are line side CTs, hence, 220 kV Bus bar relay was taken out of

service to avoid any mal-operation.


Committee observed that tripping of elements from remote ends was in order, since

the Bus bar protection was out of service. However proper operating instructions

should be followed during transfer operations and Bus bar protection should always

be kept in service.

2.29. Occurrence on 02.11.2015 at 220kV Omkareshwar Hydel Power station –

MPPGCL representative stated that on 02.11.2015, at 10:50 Hrs, during changing of

Isolators from Bus 220 kv Bus B to Bus A, Both isolators got opened simultaneous

creating arcing and Bus fault on both the 220 kV Buses. The Bus fault was R-Y phase to

phase fault. With operation of Bus bar protection all the elements and Units tripped from

220 kV Omkareshwar Sub-station causing complete blackout. Total generation loss during

the event was 116 MW.

Committee observed that the operation of Bus Bar protection was in order. However

routine maintenance of Isolators be carried out at regular intervals.


C. OCCURANCES IN MAHARASHTRA SYSTEM

2.30. Occurrence on 05.05.2015 at 400 kV Bableswar S/s: MSETCL representative

stated that on 05.05.2015 at 09:33 Hrs, R phase CB grading capacitor of 400 kV reactor got

burst and created 400 kV bus fault. Busbar protection operated and all elements connected

to bus I tripped. As ICT – I & II tripped (connected to bus - I), ICT – III (connected to bus

- II) got over loaded and its load trimming scheme got operated (Sifang CSC211 make

relay) after 1.5 sec (the relay has three functions – HV directional O/C, LBB & Load

trimming). Subsequently LBB of ICT – III operated i.e. after 1.7 sec, all elements

connected to bus – II tripped.

One of the interrupter of the reactor CB (Double break interrupter) couldn’t open(stuck

up), led to unequal voltage across grading capacitor and 230 kV appeared across grading

capacitor and got burst. The reactor switching operations is carried out every day to control

voltage. Further he intimated that LBB function is getting initiated with triggering of any

function i.e. O/C, E/F or over load. However due to internal initiation of LBB function

provided in the relay used for load trimming scheme of ICT, LBB protection of ICT-III get

operated. There are 3 functions viz. 1) O/C 2) O/L and 3) LBB used in ICT-III HV Side

relay CSC211. ER Company representative changed the firm ware of the relay to disable

internal initiation of the LBB.

All elements were restored by 11:55 Hrs.

Committee observed that the operation of LBB was undesired and the corrective

actions have been by MSETCL. Further wherever reactors are switched in and

switched out frequently, its breaker should be provided with CSD(Controlled

switching Device).

2.31. Occurrence on 08.05.2015 at 400/220 kV Kalwa S/s: MSETCL representative

stated that on 08.05.2015 at 14:55 Hrs R ph wave trap of 400 kV Kalwa – Padghe – I

(connected to main bus – II) got burnt and its jumper got broken in the vicinity of 400 kV

main bus – I at Kalwa S/s. Hence busbar protection of 400 kV main – I operated and all

elements connected to this bus got tripped along with bus coupler. Thus 400 kV Kalwa S/s

was left with only one feeder i.e. 400 kV Kalwa – Talegaon and 400 kV Kharaghar left

with only one feeder i.e. 400 kV Kharghar – Padghe. Thus load on 220 kV Boisar (PG) –


Boisar D/C increased even after operation of load trimming scheme. During this

occurrence the total amount of load shedding was 632 MWs. All elements except 400 kV

Kalwa – Padghe – I were restored by 16:00 Hrs. The 400kV Kalwa-Padghe -1 was taken

into service on 09.05.2015at 00:21hrs after removing & bypassing the failed/burned WT at

400KV Kalwa s/s.

Committee observed that the operation of Bus bar protection was in order.

Thermography of wave traps should also be done and trending should be supervised

to ascertain developing hot spots.

2.32. Occurrence on 08.05.2015 at Bableshwar Sub-station, Maharashtra –

MSETCL representative stated that on 08.05.2015 at 22:58Hrs , Y Phase CT of 220 kV

Bableshwar-Ahmednagar circuit 1 has burst at Bableshwar Sub-station which led to Bus

fault on 220 kV bus 1 and operation of bus bar protection for zone 1. This has led to

tripping of 400/220 kV 315 MVA ICT 1 and 2 at Bableshwar along with 220 kV lines

connected on the bus. With these the complete load has shifted to 400/220 kV 500 MVA

ICT 3, which got overloaded and tripped on H/V side backup over current protection. With

this the 220 kV circuit got overloaded and tripped one by one on overcurrent protection.

This resulted in complete black out of 220 kV bus at Bableshwar and loss of Ahmednagar

load. With this, the loading of 400 kV Bableshwar-Padghe D/C got increased and 400 kV

Bableshwar-Padghe 1 tripped on overcurrent protection, which was in enable condition at

Bableshwar end. With these, the loading of other parallel circuit has increased to more than

1000 MW. Further the 400/220 kV ICT 1, 2, 3 got overloaded at Padghe sub-station due to

shifting of load which were fed from Bableshwar resulting in load trimming scheme

operation for ICT 3.

During the above occurrence, load loss during the first event was 409 MW while in second

event it was 323 MW. All elements were restored by at 01:38 Hrs on 09.05.2015.

WRLDC representative stated that there is a GPS synchronization problem at Bableshwar

S/S and therefore analysis of disturbance at this S/S becomes difficult.

Committee felt that 400kV Bableshwar-Padghe set for tripping on over load(over

current) was surprising. MSETCL representative intimated that the over load

tripping for this line was set 9 years back. Committee suggested to review all the

settings and block/remove the over load tripping schemes on 400kV lines in MSETCL


system. Further the event logger and the GPS synchronization problem at

Bableshwar S/S should be rectified.

2.33. Occurrence on 02.06.2015 and 12.06.2015 at Mouda and IEPL –WRLDC

representative stated that on 2nd June 2015 at 16:34 Hrs, 400 kV Wardha-Mouda circuit

and 400 kV Wardha IEPL circuit tripped on single phase to earth fault which resulted in

loss of evacuation path for Mouda system causing tripping of Unit 2 of Mouda. This led to

blackout of Mouda and IEPL S/s.

While on 12th June 2015 at 19:08 Hrs. again the 400 kV Wardha-Mouda circuit and 400

kV Wardha IEPL circuit tripped on single phase to earth faulty resulting in loss of supply

at Mouda and IEPL. During event on 2nd June 2015, Generation loss of 265 MW occurred

with tripping of Mouda Unit 2. No Generation loss occurred during event on 12th June

2015.

All the elements were restored by 21:27 Hrs on 02.06.2015 for the first fault. For the

second fault, all the elements were restored by 22:13 Hrs on 12.06.2015.

Committee observed that the tripping of unit at Mauda on 20.06.2015 was due to

complete loss of evacuation at Mauda S/S.

2.34. Tripping of 765/400 kV Aurangabad ICTs on 03.06.15: WRLDC representative

stated that 765/400 kV 1500 MVA Aurangabad ICT 2 tripped on 3rd June 2015 at 13:12

Hrs on Buchholz Relay mal-operation. This has resulted in the overloading of the 765/400

kV ICT 1 at Aurangabad which endangered the N-1 reliability criteria for Maharashtra

system. As a measure to relieve the loading on the ICT, 765 kV Seoni-Wardha 1 and 765

kV Wardha-Aurangabad 3 were hand tripped. It may be observed that to control ICT 1

loading in the system, two 765 kV lines have to be switched off which affect the system

reliability.

Further earlier also, this ICT have tripped either on mal-operation of Buchholz relay or

WTI, which has put the system in Alert state.

Committee felt that frequent mal operation of Buccolz relay of ICT 2 is undesirable

and MSETCL should thoroughly check the Buccolz & WTI relays for its mal

operation.


2.35. Occurrence on 10.06.2015 at 400/220 kV Chandrapur, Maharashtra –

MSETCL representative stated that on 10.06.2015 at 17:00 Hrs , B phase fault occurred on

220 kV Chandrapur- Railway TSS 2 circuit due to insulator string failure. The fault was

not cleared by the distance and earth fault protection at Chandrapur end. This resulted in

fault feeding from all the incoming feeders, which have tripped from remote ends or

backup protection. This led the 220 kV Bus to become dead and loss of generation of

Chandrapur Unit 2 (143 MW) and loss of radial load of Gadchiroli (100 MW).

He further stated that the CT secondary wires of 220kV Chandrapur-Railway TSS 2 circuit

were damaged and got earthed.

Most of the elements were restored by 23:52 Hrs on 10.06.2015. 220 kV Charndrapur-TSS

1 at 20:42 on 11-06-15. Chandrapur – Warora and Chandrapur-Wani remained out.

Committee felt that meggering of CT cables should also be done during routine

maintenance of CTs.

2.36. Occurrence on 12.06.2015 at 220 kV Parli GCR Sub-station – MSETCL

representative stated that on 12.06.2015 at 17:27 Hrs, due to Bursting of 220 kV R Phase

CT of 220 kV Parli-Nanded 1 cricuit , its bus bar protection for 220 kV Bus 1 operated and

tripped all the connected elements. This has led to tripping of Parli unit 1 and loss of 229

MW of generation.

Further he stated that the 220kV Parli-Nanded ckt-1 tripped on R-N fault at 16:46hrs and

DPS operated in Zone -1 from both ends. At 17:27hrs while charging the line from Parli

end the R phase got burst.

All the elements were restored by 18:56 Hrs on 12.06.2015. The failed CT was replaced on

13.06.2015.

Committee observed that the trippings were in order.

2.37. Occurrence on 13.06.2015 at 400/220 Akola Sub-station – MSETCL

representative stated that, after replacement of LV side Y Phase CT of 400/220 kV 315

MVA ICT at Akola S/s, while the charging of the ICT, the replaced CT got burst, resulting

in Bus fault on 220 kV Main Bus (220 KV Bus of Akola having SMT scheme) leading to

tripping of all 220 kV elements. This has led to load loss of 12 MW for 28 Minutes.


The old CT tan delta value were on the higher side and therefore was replaced with ITC

make new CT.

After system restoration, the Y phase CT of the ICT was replaced and was being charged at

20:57 Hrs. Again the replaced CT got burst causing Bus fault on 220 kV Main Bus (220

KV Bus of Akola having SMT scheme) leading to tripping of all 220 kV elements. This

has led to load loss of 16 MW for 12 Minutes.

All the elements were restored by 01:06 Hrs on 13.06.2015 for the first fault and for the

second fault all the elements were restored by 13:21 Hrs on 14.06.2015.

Committee observed that the operation of Bus Bar protection was in order.

2.38. Occurrence on 13.06.2015 at 400/220 kV Deepnagar Sub-Station, Maharashtra

– MSETCL representative stated that on 13.06.2015 at 14:50 Hrs, 400 kV Deepnagar-

Aurangabad Circuit tripped on distance protection operation due to B phase to Earth fault.

As the Generation Unit 4 was connected via Tie CB only (as its Main CB was out since its

replacement after 24th April 2015 event) resulting in its tripping. This has led to loss of

Unit 4 generation causing generation loss of 367 MW.


Committee felt that the tripping was in order. However the Main CB should not have

been kept out of service for so long.

2.39. Occurrence on 24.06.2015 at 400/220 kV Khargar sub-station, Maharashtra –

MSETCL representative stated that on 24.06.2015 at 01:26 Hrs, the 400 kV R & B phases

of 400 kV transfer bus Isolator of the 80 MVAR Reactor bay partially got opened while in

service and thus created 400 kV transfer bus fault. However due to non-operation of

directional unit of bus bar scheme the transfer bus, 400 kV Main bus-II bus bar protections

has operated at 400 kV Kharghar sub-station. Due to this all elements connected to 400 kV

Bus 2 at Khargar tripped. There was no generation/load loss during the event.

He further informed that on 21.06.2015, the 400kV Main bus – II outage was taken for

alignment of 400kV Main bus –II isolator of newly commissioned 315MVA,

400/220kV ICT-III at Kharghar s/s. The normalization of 400kV Main bus-II was started at

23.54hrs on 23.04.2015. The 400kV Padghe & 315MVA, 400/220kV ICT –I was shifted


from 400kV Main bus – I to II. The 80MVAR reactor was being taken on 400kV Main bus

– II through its own circuit breaker, but due CB problem it was not taken on own breaker.

therefore it was decided to take the 80MVAR reactor on TBC. At 01:16hrs on 24.06.2015,

the reactor was taken on TBC. At 01:26 hrs, the 400kV R & B phases of 400kV C- Bus

Isolator of the 80MVAR Reactor bay remained partially open on load creating 400kV

transfer bus fault. Under this circumstances, only 400kV Reactor TBC CB should have

tripped & isolate the bus fault. The 80MVAR reactor was on TBC through 400kV Main

bus-II. However it is observed that directional unit of bus bar protection is found to be not

operated resulting in BB operation of Main Bus-II. He further informed that till the

directional unit is repaired/replaced the transfer bus will not be used.

Most of the elements were restored by 09:32 Hrs on 24.06.2015. 400kV Reactor was not

taken in service due to system constrain.

Committee observed that the operation of Main Bus-II Bus bar protection was

undesirable and the corrective actions have already been taken by MSETCL as

described above.

2.40. Occurrence on 10.07.2015 at 220 kV Talegaon Sub-station – MSETCL

representative stated that on 10.07.2015 at 11:30 hrs, Bus bar protection for 220 kV Bus 1

operated at 220/22 kV Talegaon Sub-station resulting in tripping of all elements connected

to 220 kV Bus 1. There was no fault in the system during the operation of Bus bar

protection. After analysis it was found that bay indication wires of 220 kV Pune (PG) -

Talegaon 1 line was found in burnt condition and has caused shorting of the DC resulting

in Bus bar protection. LBB trip bus 1 i.e. P5 found charged. Indication +ve L1 & P5 found

shorted on 29 AX isolator contact multiplication relay in control panel of 220kV PGCIL-I

line. In control panel of 220kV PGCIL- I line bay indication wires found heated & burnt on

semaphore resistance which caused shorting of DC. Same was removed & attended by

testing.


Committee observed that the tripping was unfortunate and suggested that regular

check up of wirings in relay panel be done and proper distance be maintained

between the series resistors used in indication circuits and other wires passing near

by.


2.41. Occurrence on 10.07.2015 at 220 kV Parli GCR – MSETCL representative stated

that on 10.07.2015 at 13:05 Hrs, during the Trial of Transfer bus coupler of GT-1, the 220

kV Bus bar protection of 220 kV bus 1 and Transfer Bus operated which resulted in

tripping of all elements connected with bus 1.

The 220kV GT-1 was connected to Bus-2. For taking TBC trials of GT-1, 29C of GT-1

was closed and 29C & 29B of TBC bay was also closed. NIT switch was taken on inter

position and TBC breaker was closed. Own breaker of GT-1 was handtripped and NIT

switch was taken on transfer position. Protection trial through Buccolz trip of GT-1 was

taken and the TBC tripped correctly. However while charging GT-1 through TBC breaker

BB protection Zone-1 & Zone-3 operated. On investigation it was found that the 29C

status of 220kV Beed Ckt 2 which was connected to Bus-1 was high due to position of

switch provided for isolator status and remained in closed position though the isolator wa

physically open. This wrong status of 29C of 220kV Beed Ckt 2 along with 29C of GT-1

resulted into an unforeseen/untested condition for Bus bar protection. The charging current

of GT-1 resulted into differential operating Zone-1 & Zone-3 of Bus Bar protection.

Blocking of BB protection operation as expected in this condition did not happen. The

occurrence has been referred to M/s Alstom for their comment.

During the event there was no load/generation loss.


Committee observed that the behavior of BB relay under such conditions need

through analysis and the comments of M/s Alstom be shared in this forum.

2.42. Occurrence on 28.08.2015 at 400/220 kV Karad Sub-Station – MSETCL

representative stated that on 28.08.2015 at 16:11 Hrs, while opening 400 kV Karad-

Kolhapur 1 for voltage control at Karad sub-station, R phase pole of ABB make circuit

breaker got burst at Karad Sub-station resulting in bus fault on 400 kV Bus 1 at Karad.

This led to bus bar protection operating and thus tripping of all elements from 400 kV Bus

1. Further after this the 400 kV Karad-Kolhapur 2 circuit has also tripped on overvoltage.

During the event there was no generation/load loss.



Committee felt that the cause of failure may be due to opening/switching off of CB of

400kV Karad-Kolhapur#1 line on high voltage. The manual switching operations to

over voltages may commence at 105-110% as advised in the earlier PCMs.

2.43. Occurrence on 16.09.2015 at 400/220 kV Chandrapur Sub-station - WRLDC

representative stated that on 16.09.2015 at 20:32 Hrs, due to LBB initiation of Chandrapur

Unit 6 which was on 400 kV Bus 2, all elements connected to 400 kV Bus 2 at Chandrapur

2 tripped.This led to loss of Unit 2 and Unit 6 causing 432 MW generation Loss.At

19:25hrs., low air/gas pressure lock out window indication for GTR-6 CB appeared, due to

low air pressure and failure of compressor AC supply. Mean while the field failure

protection of GTR-6 operated at 20:32hrs, before the compressor AC supply could be

restored, resulting in a stuck breaker condition and operation of LBB.

Most of the elements were restored by 22:12 Hrs on 16.09.2015. 400 kV Chandrapur-

Parli, Chandrapur Unit 2 and Chandrapur Unit 6 was restored on 17.09.2015.

Committee felt that the compressor AC supply could have been restored/attended as

soon as the appearance of the “air pressure low lock out” window indication, so that

the LBB operation could have been avoided.

2.44. Occurrence on 23.10.2015 at 220 kV Miraj S/s, Maharashtra - WRLDC

intimated that23.10.2015 at 00:23 Hrs,Y phase CT of 220 kV Vita bay burst at 220 kV

Miraj Sub-station which resulted in Bus fault at the station. This led to Bus bar protection

operation at the sub-station. With this all the 220 kV elements connected at Miraj sub-

station tripped causing blackout at the station and nearby radial connected loads. There

were loss of 206 MW of Load during the event.


Committee felt that the operation of BB protection on CT failure was in order.

2.45. Occurrence on 28.10.2015 at 400/220 kV Parli (MS) Sub-station – MSETCL

representative stated that on 28.10.2015 at 21:17 Hrs, due to differential protection

operation of 400/220 kV 315 MVA ICT 2 at Parli (MS), the 400/220 kV 315 MVA ICT 1

and 500 MVA ICT 3 at Parli (MS) got overloaded and its load trimming scheme operated.

This led to loss of 241.7 MW and energy loss of 1881 MWhr. He further informed that the


400/220kV, 315MVA ICT-2 tripped on differential protection due to burning of CT

differential core-1 wire in CT terminal box. The CT cable cores were replaced.


Committee felt that the operation of differential protection due to burning of CT

differential core-1 wires in CT terminal was in order and recommended that

meggering of CT cables be done during the routine maintenance of the CTs.

2.46. Occurrence on 28.10.2015 at t 765/400 kV Dhule BDTCL Sub-station -

WRLDC intimated that on 28.10.2015 at 14:39 Hrs, at 765/400 kV Dhule substation, the

765 kV Dhule- Aurangabad line, 765 kV Dhule-Vadodara line, 765 kV 240 MVAR Bus

reactor, 765/400 kV, 1500 MVA ICT-1 & 2 got tripped simultaneously at 14:39 Hrs. This

resulted in complete blackout of Dhule BDTCL sub-station however as there is no direct

load connected so no interruption has occurred anywhere.

Prior to the event, all the elements from 765/400 kV Dhule were in service. 400 kV

Dhule(BDTCL)-Dhule (MS) D/C were in idle charged condition due to non-

commissioning of bays at Dhule(MS) Sub-station. Prior to the event there were heavy

rainfall and thunderstorm in the area. At 14:39 Hrs, B phase Lightening arrester of

line reactor of 765 kV Dhule-Aurangabad circuit at Dhule end failed causing line fault

on the circuit. The fault was sensed in Zone 1 from Dhule end and A/R was initiated

with single phase tripping. However the same fault was also sensed by Relay at 765

kV Dhule-Vadodara line at Vadodara end in Zone 1 and it also initiated the single

phase tripping with A/R initiation.

It was intimated by Dhule BDTCL that during the A/R period, 765/400 kV Dhule

ICTs got tripped on neutral O/C protection and the 765 kV Bus reactor on backup

impedance protection. However as observed from the Event logger the tripping of

ICT/Bus reactor breakers are after the loss of these two feeders.

After 1 second, A/R initiated on both circuits and the reclose command was given by

relay however due to permanent nature of fault the lines tripped on three phase trip.

With this the 765 kV Dhule A’Bad circuit tripped from both ends while Dhule-

Vadodara circuit tripped from Vadodara end.

With the loss of incoming feeder the total loss of supply occurred at 765/400 kV

Dhule BDTCL s/s.


Most of the elements were restored by 23:48 Hrs.

Committee felt that tripping of 765 kV Dhule A’Bad was in order. The tripping of

765kV Dhule-Vadodara circuit from Vadodara end in Zone-1, 765/400 kV Dhule

ICTs got on neutral O/C protection and 765 kV Bus reactor on backup impedance

protection was undesirable. Committee requested PGCIL to check the over reaching

of DPS from Vadodara end and BDTCL to ascertain the cause of tripping of 765/400

kV Dhule ICTs and 765 kV Bus reactor.

2.47. Occurrence on 30.10.2015 at 400/220 kV Parli (MS) S/s - WRLDC vide letter

no. WRLDC/MO-3/1658/2015/1618 dated 10.11.2015 intimated thaton 30.10.2015 at

19:10 Hrs, B phase bushing of 400 kV, 50 MVAR Line Reactor of 400 kV Parli (MS)-

Lonikand2 circuit 2 burst and reactor caught fire. This resulted in single phase fault on the

circuit and line protection operation in Zone 1 with single phase carrier aided trip. In

between fault also appeared on Y phase resulting in tripping on line on three phase trip.

Along with this, 400 kV Parli(PG)-Parli(MS) 1 & 2 and 400 kV Chandrapur2-Parli circuit

2 also tripped on Zone 1 carrier aided trip. Fault was severe in nature and high fault current

were observed.

He further informed that initiation of event was due to failure of ‘B’ phase (RYB) bushing. The

fault was seen as a B-N fault by line distance protection in zone-1 and single pole trip was

issued. Single pole breaker opened at @ 61 mSec after fault initiation. One more fault appeared

at @ 62.5 mSec after B phase fault clearance. This was a Y-N fault and was sensed correctly in

Zone-1. A three pole trip was issued by distance protection relay for this fault and reactor was

isolated from network from both ends. The second fault was cleared in @80 mSec. The 86R

operation is seen at @ 229 mSec after first fault initiation in the disturbance record of Main 1

distance protection. The reactor caught fire and the bushings, LAs, radiators were totally

damaged. The initial bushing fault being in the zone of distance protection was cleared by it

correctly. Subsequent fault was also instantaneously cleared by distance protection. The reactor

differential relay was subsequently tested and results found normal. The reactor auxiliaries

seem to have operated subsequently in 229 mSec as seen by 86R operation in disturbance

record. The routines of diagnostic measurements (capacitance, tan delta, SFRA and other

electrical tests) had not indicated any problem with the bushing or reactor.

There was no load/generation loss during the event.

Most of the elements were restored by 15:07 Hrs. 400kV Chandrapur-II was under outage.


Committee felt that the tripping of 400kV Parli (MS)-Lonikand 2 ckt#2 was in order.

Tripping of 400kV Parli (PG)-Parli (MS) in Zone-1, might have occurred due to short

lines. However the 400kV Chandrapur2-Parli ckt2 tripping in Zone-I from

Chandrapur end was undesirable and the protection have over reached, therefore the

DPS setting at Chandrapur end needs to be reviewed.

2.48. Occurrence on 07.11.2015 at 400/220 kV Parli Sub-station – MSETCL

representative stated that on 07.11.2015 at 10:20 Hrs, due to snapping of 220 kV B phase

jumper between Bus sectionalizer circuit breaker to Bus section 1 isolator Bus fault was

created at 220 kV Bus 1 at 400/220 kV Parli Sub-station. The EE CAG BB differential

relay didi not operate. Due to non-operation of bus bar protection, all 400/220 kV ICTs

tripped causing a large load loss in the Parli Area. The stablazing resistor setting adopted is

150Ohms corresponding to fault current of 15kA.

WRLDC representative stated that the amount of load loss was calculated based on

WRLDC SCADA data. It was found that around 848 MW load loss has occurred during

the event. Energy unserved during the event was around 1676 MWHr. Generation loss due

to Parli unit 8 tripping was 170 MW.


Committee felt that the CAG High impedance BB protection might have not sensed

the fault and recommended replacement of the same with numerical BB protection

scheme.

2.49. Occurrence on 20.11.2015 at Dhariwal, Maharashtra Sub-station- WRLDC

representative stated that on 20.11.2015 at 12:58 Hrsboth400 kV Circuits from Dhariwal

Sub-station tripped on df/dt Protection setting operation in P141 Relay which is used for

islanding of CTU section of the Dhariwal substation from STU section. Tripping of these

circuit has caused blackout of Dhariwal sub-station. There was no Generation loss during

the event. As per the detailed analysis and corrective action presented by Dhariwal, the

df/dt protection in MICOM P141 & Vector shift protection in Vector Surge relay MICOM

P341 used for Islanding purpose in CTU section had been disabled.



Committee felt that the tripping has resulted due to enabling the df/dt settings in

MICOM P341 relay inadvertently. Committee therefore suggested that new entities

connecting to STU network shall get their settings consulted from STU of the State

and new entities connecting to CTU network shall get their settings consulted from

CTU before connecting to grid and the report be sent to SLDC/WRLDC as per the

case.

2.50. Occurrence on 16.11.2015 at 220 kV Miraj Sub-station – MSETCL

representative stated that on 16.11.2015 at 21:05Hrs, 220 kV R phase PT at Miraj Sub-

station got burst, resulting in Bus fault at the station. This led to operation of Bus bar

protection at the sub-station. With this all the 220 kV elements connected at Miraj sub-

station tripped causing blackout at the station and nearby radial connected loads. There was

loss of 110 MW of Load during the event. Failed PT was of SCT Make which was

manufactured and commissioned in 2010.

Load loss during the event was 110 MW for 20Minutes. Energy unserved was 33.67

MWHr.


Committee felt that the operation of BB protection due to failure of PT was in order.

D. OCCURANCES IN CHATTISGARH/GOA/DD/DNH/NTPC/PGCIL

SYSTEM

2.51. Occurrence on 31.05.2015 at Korba NTPC- WRLDC representative stated that

on 31.05.2015 at 20:42Hrs, due to stormy weather in the Korba and nearby area, Multiple

tripping of 400 kV line started from 20:15 Hrs at Korba NTPC sub stations on transient

faults in the following order:

1. At 20.15 Hrs, Y phase to earth fault occurred on 400 kV Korba-Vandana circuit. Fault

location was at 3.2 km from Korba end. Fault was seen in Zone 1 protection from Korba

end. Auto-reclose Lockout at Korba end due to line reactor backup protection operation.

Fault current from Korba end was 34.5 kA.


2. At 20:17 Hrs, 765 kV Sipat-Bilaspur circuit 1 tripped on R-B phase-to-phase fault. At

the same time 400 kV Korba-Balco circuit tripped from Korba end while 400 kV Korba-

Sipat tripped on Sipat end with the operation of Main 2 protection (P437 Relay) giving

only trip command.

3. At 20:17 Hrs, Y Phase to Earth fault occurred on 400 kV Korba-Raipur circuit 3 which

was in Zone 1 from Korba end. The circuit got reclosed after 1 second successfully with

operation of autoreclosure.

4. In addition, at 20:17 Hrs R phase to earth fault occurred on 400 kV Korba- Raipur

circuit 4 line and which was cleared with Zone 1 carrier aided tripping and successfully

reclosed after 1 second.

5. At 20:42 Hrs, R phase to earth occurred on 400 kV Korba-Bhatpara line in Zone 1.

Korba end has issued three-phase trip due to problem with Auto-reclosure. While Bhatpara

end has successfully reclosed.

All the elements were restored by 00:21 Hrs on 01-06-15.

Committee felt that the trippings were due to inclement weather.

2.52. Occurrence on 12.06.2015 at 765/400 kV Aurangabad Sub-station – PGCIL

representative stated that on 12.06.2015 at 09:29 Hrs, 400 kV Bus 2 at Aurangabad (PG)

sub-station tripped due to operation of Bus bar protection. With this 765/400 kV ICT 2,

400 kV Bus reactor, 400/220 kV Aurangabad ICT 1 & 2, 400 kV Boisar ckt Line

reactor 1 & 2 and 400 kV Wardha ckt Line reactor 1 & 2 tripped. The reason for the

tripping of elements is DC earth fault due to flooding of cable trench during heavy rain.

There was no interruption of load and generation during the event.


Committee noted.

2.53. Occurrence on 22.06.2015 at 220/66 kV Kharadpada Sub-station, DNH –

WRLDC representative stated that on 22.06.2015 at 12:07 Hrs, 220 kV Vapi-Kharadpada

circuit 2 tripped on B Phase to Earth fault. Within 15 second, 220 kV Vapi-Kharadpada

circuit 1 also tripped on Y phase to Earth fault. Both lines tripped leaving Kharadpada

Substation dark and resulting in a load loss of 360MW.



Committee felt that the trippings were in order and were due to genuine fault.

2.54. Occurrence on 14.07.2015 at HVDC Bhadrawati- WRLDC vide letter no.

WRLDC/MO-3/1658/2015/859 dated 05.08.2015 intimated thaton 14.07.2015 at 11:00

Hrs, pole 1 and 2 of HVDC Bhadrawati has tripped on ‘VCC1 Main Circuit

Half Flow - V-Low’ & ‘VCC2 Main Circuit Full Flow - V-Low’ alarm respectively. This

has resulted in increased loading of 400 kV Wardha-Parli D/C above 850 MW and resulted

in SPS-5 Operation causing generation reduction of 421 MW in Western region and 602

MW load reduction in Southern region.

400/220/33 kV ICT for reliable auxiliary supply was approved at HVDC Bhadrawati

Sub-station by WRPC. The 400/220/33 kV ICT was commissioned on 19 February

2015 for improving auxiliary supply arrangement. However the ICT has not been yet

been operationalized for Auxiliary supply arrangement for HVDC after the COD.

The auxiliary sets function in cross changeover mode when the any of the 33 kV

circuits(MSEDCL supply) trips or normalized.


Committee requested PGCIL to shift the auxiliary supply arrangement for HVDC on

the 400/220/33kV ICT at the earliest.

2.55. Separation of New and SR grid on on 28.07.2015- PGCIL representative stated

that on 28.07.2015 at 11:50 Hrs, 765 kV Solapur-Raichur 2 circuit tripped from Solapur

end and send direct trip command to Raichur end. After 2 minutes, the 765 kV Solapur-

Raihcur 1 circuit also tripped from Raichur end on operation of SPS-7. This led to

separation of NEW and SR grid.

The 765 kV Bus-I at Solapur was taken under planned shutdown at 11:43 hrs. The Line

CVT of 765 kV Solapur-Raihcur 2 circuit at Solapur end was faulty and was out of service.

The line protection was using 765 kV Bus 1 CVT during the period.

At 11:50:06 Hrs, 765 kV Solapur-Raichur 2 circuit tripped from Solapur end on OST and

send direct trip to Raichur end. With this the complete flow shifted to 765 kV Solapur

Raichur 1 circuit.


At 11:52:22, 765 kV Solapur-Raichur circuit tripped from Raichur end on SPS-7 operation.

However the circuit remained charged from Solapur end. With the tripping of both circuits,

NEW and SR Grid got separated.

PGCIL representative stated that the SPS-7 at Raichur end remained enabled in advertently

thereby tripping the 765 kV Solapur-Raichur 2 on overload. Further the OST feature of

DPS at Solapur end was kept enabled. Since the CVT supply was not there to the DPS and

noise appeared across the VT supply terminals of the DPS. This was sensed by the DPS as

an Out of Step condition and tripped the line.

He further informed that the SPS-7 at Raichur end has now been disabled and the OST

feature of DPS at Solapur end also has been disabled after the occurrence.


Committee observed that in line with the Ramkrishna Committee recommendations,

the power swing detected in Zone-1 should be allowed to trip the line, till proper

studies regarding placement of OST relays are carried out and OST should not be

enabled in the DPS. Further Committee suggested that the erroneous sensing of OST

condition by the DPS is not consistent with the OST detection principle. Since in this

particular case the noise/spurious voltage at the DPS relay terminals and current

flows on the line might have seen it as a power swing. However, the swing should be

sensed on the measurement of dp/dt also which could ascertain that the power swing

is genuine. In this particular case it needs to be ascertained as to whether the relay

has detected the power swing taking into account the dp/dt also. Therefore PGCIL

may refer the occurrence and ascertain the philosophy of power swing sensing used in

the relay and the same shall be shared in the next PCM.

2.56. Occurrence on 29.09.2015 at 220/66 kV Kharadpada Sub-station, DNH -

WRLDC representative stated that on 29.09.2015 at 18:46 hrs,220 kV Vapi-Kharadpara 2

tripped on R Phase fault from both ends and 220 kV Vapi-Kharadpara-1 tripped on Y-

phase O/C protection at Kharadpara only. This led to loss of supply to Kharadpada S/s

causing blackout and load loss of 380 MW. This has caused interruption in Silvasa, Dadri,

Massot and Kharadpara areas in DNH.

220 kV Vapi – Kharadpada 2 was restored by 19:52 Hrson 29.09.2015 and 220 kV Vapi –

Kharadpada 1 was restored by 00:22 Hrs on 30-09-15.


Committee felt the trippings were in order.

2.57. Occurrence on 14.11.2015 at 765/400kV Aurangabad Sub-station – PGCIL

representative stated that in the night hours of 14th November 2015, 765 kV Wardha-

A’bad 2 & 4 were in service. The system was experiencing high voltage during the period.

At 21:46 Hrs, 765 kV Wardha- A’bad 4 has tripped on overvoltage from Aurangabad end

and DT was send to Wardha end. This left Wardha and Aurangabad with single 765 kV

line i.e. Circuit 2. While charging of circuit 4 from Wardha end at 22:13 Hrs, Circuit 2

tripped from Wardha end on O/V. Subsequently circuit 4 has also tripped during the event

from Wardha end on O/V.

This led to loss of connectivity between 765 kV Buses of A ’Bad (PG) and Wardha

resulting in high loading on 400 kV Circuits. There was no load/generation loss during the

event.

Prior to the event , 765 kV Wardha-Wardha 1 lines was made out at 10:23 Hrs as per the

planned outage for balance rectification work at Sub-station and line along with

commissioning of LVCC and CSD relay. So, its switchable line reactor was also out at

Wardha end. Further at 16:30 Hrs, 765 kV Wardha-A’bad 3 was made out to control high

voltage at the sub-station. Its switchable 330 MVAr Line reactor at Wardha end was taken

in service at Wardha end at 16:50 Hrs.

At 22:55 hrs, 765 kV Wardha-A'bad 4 was charged from A'bad end but the line

tripped on operation of REF protection at A'bad. At 23:06 Hrs, 765 kV Wardha-A’bad 2

circuit was taken in service. Later at 00:29 Hrs, Ckt 3 was also taken in service.

He further informed that there are 4 Nos of 765kV Wardha-A’bad ckts, and to avoid theift

they are required to be kept in charged condition. Ckts 1 & 2 are on one tower and ckt 3 &

4 are on another tower. In view of keeping reliability and avoid theft of conductor, it is

required to co-ordinate the O/V settings by time and magnitude grading. Committee may

suggest co ordination of the O/V settings for these lines.

Committee discussed the issue at length vis a vis time and magnitude co ordination as

regards to allowing tripping of one ckt per tower and decided that following settings

may be adopted for the 4 ckts;

CktNo. O/VMagnitudesetting Timesetting

1 107% 5sec

2 107% 7sec


3 108% 6sec

4 108% 8sec

2.58. Separation of NEW and SR Grid on 04.09.2015 - NLDC vide letter no.

POSOCO/NLDC/Grid Management/791 dated 14.09.2015 intimated thaton 04.09.2015 at

19:24 Hrs, due to tripping of 765kV Raichur-Solapur Circuit-1 and Raichur-Solapur

Circuit-2. The lines reportedly tripped due to protection mal operation at Raichur end

during on earth fault in 765kV Raichur-Kurnool line. At 19:24:42 Hrs, B-phase to earth

fault occurred in 765kV Raichur-Kurnool line. It was observed from disturbance recorder

data of Kurnool station that line auto-reclosed from Kurnool end. However line did not

auto-reclose from Raichur as Auto-reclose block was observed from Event logger of

Raichur station. Line was holding from Kurnool end after auto-reclose. After 5 seconds

i.e., at 19:24:47 Hrs, over-voltage protection got operated for 765kV Raichur-Kurnool line

at Raichur end and direct trip was sent to Kurnool. Over-voltage operation was verified

with DR of Raichur and Kurnool station. 765kV Raichur-Solapur line-1&2 tripped at

around same time i.e., at 19:24:42 Hrs on operation of Group-B protection at Raichur end.

Tripping of both 765kV lines from Raichur end resulted in SR and NEW grid separation.

Both lines were in charged condition from Solapur end. It has been reported by SRTS-I,

POWERGRID that the tripping was due to operation of overcurrent protection.


Committee felt that the disturbance pertains to SR system.

2.59. Occurrence on 04.05.2015 at 400 kV Warora, 765/400 kV Tirora and 400 kV

Mouda: WRLDC intimated that at 21:50 Hrs, All the 400 kV outgoing Lines from

Warora sub-station tripped which resulted in loss of 400 kV Evacuation path of APML

Tirora. This led to overloading of 765/400 kV 1500 MVA Akola2 ICT through which

power of complete Tirora generation starts evacuating. With this SPS for ICT overlaod at

Akola2 operated and send SPS signal to Tirora leading to tripping of Unit 3 and 5 and

generation reduction in Unit 1 and 2. This led to loss of 1293 MW of generation. In

addition, Chandrapur Unit 4 that was generating 154 MW also tripped on jerk. Further, at

22:01 Hrs 400 kV Wardha-Mouda tripped on transient fault which led to loss of evacuation


path for Mouda and resulting in tripping of its running Unit 2. (Other evacuating line i.e.

400 kV Wardha-IEPL was already out on fault). This resulted in loss of 296 MW of

generation.

Events:

• At 21:40:24.095 Hrs : 400 kV Warora-Chandrapur2 circuit 1 experienced R Phase

to earth fault at a location of 33 km from Warora end. Single-phase carrier aided

tripping initiated for the circuit at both ends. After 1 second, the line successfully

reclosed at Warora end. While at Chandrapur2 end, between A/R period MICOM

P444 relay issued tripping in zone 4 leading to tripping of this line at 21:50:24.888

Hrs. Fault current was 5.38 kA from Warora end 29 kA from chandrapur2 end. At

21:50:24.435 Hrs: 400 kV Warora-Chandrapur2 circuit 2 tripped on Zone 4 trip

from Chandrapur2 end. Line remained charged from Warora end. Fault current

was around 5.75 kA observed in reverse direction at Chandrapur2 end.

• At 21:50:25.875 Hrs : 400 kV Warora-Wardha circuit 1 tripped at Warora end

only on Zone 2 protection operation. Line remained charged from Wardha end.

• At 21:50:54.196 Hrs: 400 kV Warora-Chandrapur2 circuit 1 tripped on receipt of

DT command from remote end.

With this the evacuation from Warora for 400 kV Tirora-Warora D/C got depleted

resulting in diversion of the power towards 765 kV Tirora-Koradi3-Akola D/C to

Akola2 substation through 765/400 kV 1500 MVA ICT at Akola2. This resulted in

overloading of this ICT as carrying 2525 MW. This led to Operation of SPS at Tirora.

• At 09:50:24.948 Hrs : Power swing SPS operated

• At 09:50:25.661 Hrs: 765 kV Line overload Stage 3 operated. Unit 5 trip

command extend

• At 09:50:25.767 Hrs : APML Unit 5 tripped

• At 09:50:25.644 Hrs : Akola2 SPS Stage 3 command send to Tirora

• At 09:50:26.118 Hrs : Akola2 SPS Stage 2 command send to Tirora

• At 09:50:26.135 Hrs : Akola2 SPS stage 2 Operated command received at Tirora.

Unit 3 trip command extended

• At 09:50:26.245 Hrs : APML Unit 3 Tripped

• Generation reduction started in Unit 1 and 2 until the loading of Akola 2 ICT

reduced below 1500 MW.


• During the same time , frequency reduced from 49.88 to 49.74 Hz i.e. 0.14 Hz


Committee felt that the fault subsequent to tripping of 400 kV Warora-

Chandrapur2 circuit 1 R Phase to earth fault, a fault appeared behind

Chandrapur2 bus and was sensed by Main-I & Main-II relays at Chandrapur2

end in Zone-4.

ITEM NO. 3: Tripping of lines / ICTs : The minor incidences of tripping of lines and

ICTs during the period 01-05-2015 to 30-11-2015 are enclosed at Annexure–3.

Committee noted.

ITEM No. 4: Occurrence on 29.03.2015 at Akola S/s

On 29.03.2015 at 14:04 Hrs, tripping occurred on many lines of WR due to

non-clearance of fault on 400 kV Akola2 – Taptithanda – II. At both (Akola2 &

Taptithanda) these sub-stations both main & backup protection of the line failed to operate.

It was followed by tripping of 765/40 kV ICT at Akola2 S/s, resulted in isolating the 765

and 400 kV systems at Akola2 S/s. After this, 400 kV Wardha – Akola D/C tripped from

Wardha end, 400 kV Koradi2 – Indiabulls from Koradi2 end and 400 kV Akola –

Bhusawal from Bhusawal end on distance protection. Further various other lines also

tripped on O/V protection and isolated the faulty section from the grid. During this, unit 2,

3 & 5 at Indiabulls (Rattan India) generating station (Gen: 440 MW) and Unit 8 (Gen: 110

MW) at Koradi – II generating station tripped on standby E/F protection. During this event,

Indiabulls S/s got block out and 400 kV buses at Akola and Akola2 S/s got dead.

The disturbance was discussed at length in the 124th PCM and it was felt

that after receiving details from above S/ss, a subgroup comprising of representatives from

WRLDC (Smt. Pushpa Sheshadri), MSETCL (Shri. Tijare), PGCIL (Shri.Anand Dubey &

Shri G. Shinde), APL (Shri.Uday Trivedi) & TATA Power (Shri. G.T.Jawale) and WRPC

would analyze the above disturbance and prepare a report on the same.

The data pertaining to above disturbance was received from the S/Ss affected and a

meeting was held on 16.10.2015 at WRPC Mumbai, wherein Shri Prakash

Kingaonkar(MSETCL), Shri C.R.Dhawale(MSETCL), Shri Ravi Wadyalkar

(PGCIL), Smt. C Ghangrekar(WRLDC), Shri MallaMahendranath(WRLDC), Shri

Sanjay Bhatt (APL), Shri GirishJawale (TATA Power), Shri P.D.Lone (WRPC) &


Shri Satyanarayan S. (WRPC) participated in the meeting and the disturbance was

discussed and analyzed in depth. Based on these discussions and analysis a report on

the disturbance was circulated vide letter dated 02.11.2015 and is available on WRPC

web site.

Conclusions& Recommendations of the group :

• Human Factor at 765/400 kV Akola2 Sub-station

The Group recommends that the well known protection principle of tripping a line once

both DPSs are blocked and the cause for blocking the DPS could not be fixed within

shortest possible time, should be strictly followed. Otherwise operation of protections from

remote ends would disrupt larger areas and their operation can be bit surprising at times.

The strategy to be followed when both DPS gets blocked should be informed to the Sub

Station operating staff.

Other protection issues :

1.The commissioning should have been done with proper testing and checking of all the

wiring and logic prior to charging of the lines at 765/400 kV Akola2 Sub-station. Proper

testing to be done for all the connection prior to charging of new lines. All utility must do a

proper check of all the connections and verify the connections using injection kit.

2.The system near about Akola (Akola, Wardha, Koradi, Chandrapur, Khaparkheda&

Aurangabad) is complex and have many complexities as regards to Main/Backup

protection settings. A coordinated setting of Main/backup relays at the complex of Akola is

required to be arrived at, considering the In-feed/Out-feed effect by simulating faults at

various locations. Hence the traditional/Ramkrishna Committee recommendations would

be required to deviate.

PGCIL, Maharashtra STU, M/s MEGPTCL and Indiabulls representatives in co

ordination with WRLDC & WRPC may sit together and decide proper settings.

3.Utility intending to connect new elements to either STU network/CTU network should get

all the settings verified from STU/CTU and STU/CTU shall make an effort to revise & co-

ordinate the relay settings in the nearby system.

4.WRLDC/SLDC instruction to be strictly adhered while carrying out any work in the

Interconnected Grid.Any online relay work if need to be performed should be first

informed to respective SLDC or RLDC for permission.

Overvoltage grading of Akola and nearby stations is required to be done.

• WRLDC instruction :


The line was charged based on the confirmation of details from Maharashtra SLDC that

they were receiving the online data of this line at their SCADA system. In view of critical

system conditions, WRLDC have permitted test charging of the line for 15mins only. After

15 minutes of the line charging, the line should have been switched off. Unfortunately the

fault occurred on the line just after 15mins.Therefore in case of any issue this should have

also been reported to WRLDC as the data of this line was not available at WRLDC end.

Also WRLDC may review its policy, as to why test charging of lines for such a small

durations are permitted. Policy may be discussed in OCC.

• Non-Availability Data of Maharashtra System at WRLDC SCADA

The most of the Maharashtra system real-time data from Maharashtra system was not

available at WRLDC, which makes system monitoring in Maharashtra at WRLDC very

difficult. WRLDC has to rely completely on Maharashtra SLDC.

Committee as regards to recommendation at sr. no. 3 under “Other protection issues”

is quoted below

“3) Utility intending to connect new elements to either STU network/CTU network should

get all the settings verified from STU/CTU and STU/CTU shall make an effort to revise &

co-ordinate the relay settings in the nearby system.”

The above recommendation was discussed at length and committee suggested

modification as follows;

“3) Utility intending to connect new elements to either STU network/CTU network,

should get all the settings vetted from STU/CTU as the case may be and the Utility shall

submit the vetted setting to SLDC/WRLDC. On confirmation of compliance of the

settings and completion of other formalities, SLDC/WRLDC shall give permission for

connecting the new element.”

ITEM NO. 5: Hon’ble CERCs orders on the Grid disturbance of 30.07.2012 &

31.07.2012

5.1: Compliance Status observations made in Protection Audit (Petition No.

220/MP/2012)

Back Ground :

CERC vide its order dated 21.02.2014 in respect to petition No. 220/MP/2012

filed by POWERGRID have directed that CTU and SLDCs shall submit quarterly

Protection Audit Report to the respective RPC latest by 15thday of the first month of next


quarter and RPCs shall submit the report to the Commission latest by 15thday of the second

month of next quarter. The Member Secretary of Regional Power Committees shall

monitor the protection related issues and bring to the notice of the Commission any

instance of non-compliance of the Regulation 1.5 of the Grid Code in respect of the

protection related issues considered in the instant petition.

The compliance status of observations made during protection audit was

reviewed in detail in a special meeting held on 18.12.2014. In this special meeting it was

observed that as per the data available with WRPC, few observations made in the

protection audit were not pertaining to protection system deficiencies (neither Category A

nor Category B) but were of system improvement related. Hence it was decided that all

observations of protection audit would be classified as protection system related i.e.

Category A, Category B & system improvement related observations, would be furnished

separately and shall not be included in the list of category A or B deficiencies.

The data for Q1 & Q2 (Qtr ending June15 & Sept 15) of 2014-15 was received timely

from MP only. After a rigorous follow up the data for Q2 was received from METCL and

CSPTCL. Gujarat have intimated that all the discrepancies of protection audit carried out

upto 2013 have been complied. The updated status received for quarter ending Sept 15

filed with CERC is available on WRPC website.

MSETCL, CSPTCL, GETCO, NTPC, PGCIL and all other transmission utilities are

requested to submit the updated status of protection audit observations regularly within 15

days of end of the quarter. Further it is observed that the protection audit observations

under category B are still not complied. Utilities are requested to comply these

observations at the earliest, since the same is being monitored by CERC and the time lines

stipulated in the CERC order are over long back. Also CERC is taking stern actions against

defaulting utilities by way of imposing penalties.

Committee decided that a special meeting would be held on 16.02.2016 to discuss the

above Item. The updated position in the above meeting is enclosed at Annexure-5.

5.2: Grid Disturbance on 30.07.2012 & 31.07.2012 (Petition No. 167/Suo-Motu/2012)

Back ground:Hon’ble CERC’s vide order dated 22.02.2014 in the matter of grid

disturbance occurred on 30.07.2012 & 31.07.2012 in petition No. 167/Suo-Motu/2012,

have made certain observations and issued directions.


According to this order, all the RPCs have to maintain the relay settings data

of all the ISTS lines and lines emanating from interface S/Ss of Utilities to ISTS (400 kV

& above and 220 kV interfacing lines). Therefore all utilities were requested to submit

relay setting data to WRPC/WRLDC.

In 123rd PCM committee requested all utilities to compile & maintain the data

of their system for voltage level of 132 kV & above. The relay setting data in respect of all

400 kV lines and important 220 kV lines (interface lines with ISTS & lines connected to

generating stations) shall be submitted to WRPC/WRLDC. Committee requested

WRLDC/SLDC to collect and compile the data of all utilities under their control area and

submit the same to RPC. The data has been received from MP, GETCO and Maharashtra.

In the 125th PCM, Committee requested PGCIL, CSPTCL, ISGS, Goa, and

DD & DNH to furnish the above data immediately.

WRLDC/SLDC may give the status on the above.



5.3: CERC Order dated 05.08.2015 on draft protocol for checking protection settings

and its healthiness (Petition No. 009/SM/2015)

Hon’ble CERC’s vide order dated 05.08.2015 in the matter of “following up actions on the

recommendations of CAC Sub-Committee on Congestion in Transmission” have

considered and accepted the Sub-Committees report and recommendations on measures to

reduce congestion in transmission for which actions need to be taken by CEA, NRCE,

CTU, POSOCO, POWERGRID, RPCs as well as CERC.

Following action to be taken by member Secretary (RPCs) have been directed by the

commission in its above order;

“Protection sub-Committee of RPC should bring out protocol for checking the settings,

ensuring healthiness of existing protection system and periodicity of carrying out this

exercise”.

In this regards a special meeting was held on 16.10.2015 at WRPC Mumbai. In the above

meeting the existing practices followed by some of the utilities on the above was informed

as follows;

a) Protection Group at Central (HQ) decides the settings and conveys to local testing/O&M

Engineers.


b) Local O&M/Testing Engineers apply these settings in the relays and reports back the

settings to HQ Protection group.

c) The HQ Protection Group checks & validates the implemented settings.

In addition to above following was decided;

d) Checking and validating of the settings be done once in a year by testing/site engineer.

e) Whenever a Grid Disturbance occurs, the relay settings of the affected station and

nearby station (where protection has mal operated) be checked thoroughly.

f) Soft copies of the settings be available at the CTU/STU HQ and the same be forwarded

to SLDCs/WRLDC for voltage levels of 400kV & above and ISTS lines (of all kV levels).

g) In case of new element to be synchronized first time, the entity should get the settings

certified by STU/CTU as the case maybe and forward the same to WRLDC/SLDC.

h) A database of all the above elements be maintained at WRLDC/SLDC.

The above was discussed in the meeting at length and following was decided;

As regards to practices followed at a), b) and c) above in Gujarat and MP system the

settings are decided in the field and are approved by HQ. Therefore Committee

suggested that the proposer can either be Local/Field testing Engineers or HQ and

the approver for these settings can be HQ and Local/Field testing Engineers

respectively.

Further, as regards to recommendation for practice at g) regarding new element

synchronization for the first time, Committee suggested that the parameters/fault

levels regarding the incidental system to the new elements be provided by CTU/STU

as the case may be to the Utility proposing to connect the new element and the

settings arrived by the Utility be got verified from CTU/STU. For this the Utility

proposing to connect the new element shall approach CTU/STU as the case may be.

The verified settings shall be adopted by the Utility and same shall be communicated

to WRLDC/SLDC as the case may be and thereafter WRLDC/SLDC shall give

permission for synchronization for such elements after completion of all other

formalities required as per regulations in vogue.

In case of any network changes, the same shall be communicated by CTU to WRLDC

and all the utilities which are required to revise settings shall be intimated the

changes in the network by CTU through WRLDC.


ITEM NO. 6: Status of implementation of recommendations of Report on Grid

disturbance on 30th and 31st July 2012 in WR.

Back ground: An enquiry committee was set up under the chairmanship of Chairman,

CEA to enquire into the grid disturbance on 30th& 31st July, 2012 in NEW grid. As per the

recommendations of this committee, all utilities/SLDCs/RLDC were required to submit

updated status on implementation of recommendations made by the committee to RPC on

1st& 15th of every month and the same has to be sent to CEA by RPC by 3rd& 17th of every

month.

The nodal officers responsible for submission of data to RPC were identified

in 120th PCM. In 120th, 121st, 122nd, 123rd PCMs & in a special meeting held on

18.12.2014, nodal officers were requested to forward the data regularly for onward

submission of the same to CEA/MoP.

In a special meeting held on 18.12.2014, it was decided that the status shall be submitted

year wise separately for FY 2012-13 & 2013-14 and the data may be furnished on

quarterly basis for April – 2014 onwards.

In the 123rdPCM, Committee observed that there were discrepancies or

mismatch in respect to protection audit data furnished by utilities for submission to CEA in

format and to CERC in format. It was opined that to have a clear picture of implemented

status on above recommendations in respect of protection audit, utilities may submit the

consolidated and detailed status of all 132 kV, 220 kV, 400 kV and 765 kV S/s. It was also

felt that SLDCs and WRLDC would coordinate to get the details.

Fortnightly data is being received from MP only. All other members are

requested to furnish the data regularly, every fortnight.

Committee decided that a special meeting would be held on 16.02.2016 to

discuss the above Item. The updated position in the above meeting is enclosed at

Annexure-5.

Item No. 7: Report of the Task Force on Power System Analysis Under

Contingencies: Ministry of Power, GoI constituted a ‘Task Force on Power System

Analysis under Contingencies’ in December 2012 under the chairmanship of Shri V.

Ramakrishna as per the recommendation made by Enquiry Committee headed by

Chairman, CEA on grid disturbances that took place in NEW grid on 30thand 31stJuly

2012. The terms of reference of Task Force broadly cover analysis of the network behavior

under normal conditions and contingencies, review of operational philosophy of protection


relays, review of islanding schemes and technological options to improve the performance

of the grid.

The report of the Task Force was discussed briefly in 122nd PCM and

subsequently discussed in detail in a special meeting held on 18.12.2014. A brief on

suggestions given by Ramakrishna Committee, discussions/observations of the group and

PCM are as follows.

1) Review & correction of relay settings:

a) Zone-3 setting: The task force recommended that Zone-3 settings should be

coordinated with lower level voltages (time grading) without compromising reach i.e.

settings should reach farthest bus. To achieve this Z-3 time should be increased to 1.5 sec.

Status/existing practices and views of constituents updated in 125th PCM:

GETCO: Z-3 settings cover longest line but doesn’t enter lower level network.

MSETCL: They are able to coordinate Z-3 settings with downstream network.

MPPTCL: Proper setting of high set of O/C relay of ICT may give an opportunity to

coordinate Z-3 time settings with downstream network.

PGCIL: It may not be possible to coordinate Z-3 with downstream network without

increasing its time settings from 1.0 to 1.5 sec.

Decision in PCMs: As per the recommendations of task force, Z – 3 reach can’t be

compromised. Also increasing Z-3 timings to 1.5 sec may not be good practice as fault

feeding for such long period is not good for the health of the equipment. Solutions may be

given case to case basis as per the requirement.

Committee observed that since no information was received from utilities regarding

difficulties in implementation of above recommendation, therefore constituents were

again requested to identify the lines where Z–3setting is over reaching into the lower

voltage system, if any, at the earliest and intimate the same to WRPC. The

consolidated views/difficulties in implementing above recommendation can then be

put up NPC/CEA.

b) Zone-1 PSB: The task force recommended to trip if power swing enters Zone – I

characteristics and block tripping for other zones during power swing.

Status/existing practices and views of constituents updated in 125thPCM :MSETCL &

NTPC representatives intimated that power swing is blocked for 2 secs for all 3 zones i.e.

Z-1, Z-2 & Z-3 and if power swing still persist the relay will trip for all 3 zones.


MP, GETCO, CSPTCL& PGCIL: If power swing enters in Z-1, relay trips immediately

and when power swing is in Z-2 or Z-3, trip is blocked.

Decision in PCMs : All existing relays may not have feature of delayed tripping for one

zone & blocking for other zones i.e. delayed tripping for Z-I and blocking for Z-II & Z-III,

hence all utilities shall instantaneously trip for Zone – I power swing and block the tripping

for power swing in other zones(Z-II & Z-III). Specific stations where this is not possible

may be identified and put up in the next PCM.

In the 125th PCM, PGCIL, MPPTCL, CSPTCL and GETCO representatives

intimated that there settings(PSB) are already in line with above recommendation.

Committee requested MSETCL and NTPC to implement the above recommendations

at the earliest. It opined that state SLDC / STUs shall ensure the implementation of

above recommendations by private utilities, IPPs etc.., within their system/control

area.

MSETCL informed that they have adopted the setting to trip if the power swing

enters in Zone-I and block tripping for other zones during power swing.

NTPC may update the status.

c) Protection Audit: The task Force recommended for carrying out regular

protection audit for relay settings by protection application team. The protection audit shall

broadly cover important aspects philosophy, settings, healthiness of fault clearing system

etc..,

Decision/Discussion in PCMs: First party audit may be carried out every year and third

party audit may be carried out once in 5 years. Protection audit shall be carried for all S/s

of 132 kV & above and the audit should be in line with the recommendations of taskforce

report.

2) Formulation of Special groups for studies and protection coordination: The Task Force recommended forming a group for studies, protection coordination and relay settings. It also recommended that each utility should establish a protection application department with adequate man power & skills. The members of protection team shall undergo regular training to enhance their skills. Contingency and Stability Studies: The Task Force recommended to form a special

group to analyze the grid conditions and factors affecting its operation and simulation of

critical system conditions expected for forthcoming season on regular basis and suitable

operational strategy worked out.


Tuning of power electronic devices & PSS: The Task Force recommended carrying out

studies & reviewing the network at regular intervals (3-4 years) with introduction of newer

power electronic devices. The results may be implemented within next 3-4 years. It also

suggested that as this requires specialized dynamic modeling, the task may be entrusted to

reputed independent agency and implementation of tuning be entrusted to respective

manufacturer.

Decision of PCM: It was decided that MSETCL, GETCO, CSPTCL, MPPTCL, WRLDC,

POWERGRID and NTPC would nominate one member from studies side and one member

from protection side and send the name of the members to WRPC for carrying out studies

mentioned above. It was also decided that SLDC would give PSS details format for state

generators, WRLDC for IPPS and NTPC for their generators.

SE (protection), WRPC intimated that in view of the above decision, a group

was formed and a meeting of the group was held at WRPC on 22.04.2015. Following was

decided in the meeting;

(i) Operational & Off line Studies: It was decided to update the PoC Q4 case of

2014-15 with the actual network and set this as a starting point. All utilities would furnish

the bi monthly data of planned network, planned generation and anticipated load

generation for the period upto March 2016. The study group after updating the network

and receipt of the forecast data would take up the operational planning studies.

(ii) Transient Stability & Short circuit Studies: Utilities would furnish the machines

transient data of their system, wherever data is not available the same shall be assumed as

per CEA/CBIP manuals. Training on the same could be arranged with IIT-B.

It was decided that two subgroups could be formed to look into the above

recommendations. One subgroup would be headed by Shri R H Satpute, SE (Testing

Division – Vashi). This sub group would review the protection system in WR and

coordinate the relay settings as per the Ramakrishna recommendations. The other subgroup

would be headed by Shri Satyanarayan. S, SE (P&S), WRPC. This subgroup would carry

out studies required for coordination of relay settings.

iii) In house training:

Task force strongly recommended that a dedicated group is required to be trained in all

utilities to carry out computer aided studies for relay settings.


It was felt that knowledge sharing sessions / discussions, in house training on the

fundamentals of load flow studies, contingency studies, stability studies etc.., may be

shared with the system study engineers of utilities of WR.

iv) Training by IIT: In order to build a strong team of WR in specialized areas of studies,

training sessions may be arranged to team members at IIT Bombay on relevant specialized

areas subjects like transient stability, PSS tuning, tuning of FACTs devices, SSR etc..,

The proposal for this training shall be put up for upcoming WRPC board meeting and as

the reactive energy account (REA) fund was transferred to PSDF, the funding for this

training may be taken up in this meeting.

vi) On line studies & State Estimation: An update on the online studies (Online state

estimation and contingency rankings etc) being carried out by utilities was updated as

regards to packages available with them and online studies conducting at their end.

WRLDC representative informed that in compliance to recommendation 10.1.2 of Rama

Krishna committee on Task Force on Power System Analysis under Contingencies,

WRLDC is operating Real Time Security Desk in Control Room since June’14 with an

officer conversant with system studies through PSS/E software and knowledge of

SCADA/EMS.

Presently WRLDC and SLDCs are upgrading the SCADA/EMS system. In thisnew

SCADA / EMS system complete network model of Western Region would be incorporated

which would result in effective utilization of State Estimation in real time. In the upgraded

SCADA/EMS, the plan is to run state estimation along with contingency analysis in real

time and integrate PMU data with new SCADA/EMS system which would improve

observability of network.

MSETCL representative intimated that earlier MSETCL was carrying out online studies on

Seimens State Estimator software but due to increase in network complexities and

constraint with existing S/W package, these studies were discontinued. It was intimated

that very soon MSETCL would be shifting to new S/W package, through which online

studies could be carried out.

GETCO, CSPTCL & MPPTCL representatives intimated that they are not performing

online studies.

The Committee felt that updating the all India network is a daunting task and a coordinated

effort is required for updating the network by all the regions. It was also felt that utilities

may depute representatives to WRPC for a short period on rotational basis for updating of

data and helping in carrying out the above studies. The Committee further recommended


that the proposal for this training shall be put up for upcoming WRPC board meeting.

Since the reactive energy account (REA) fund was transferred to PSDF as intimated by

WRLDC, the funding for this training may be taken up in the ensuing WRPC meeting.



3) Meeting for appointment of consultant-A to conduct the study/analysis to

ensure secure and reliable operation of national grid:

In compliance to MoP order dated 16.07.2014, the process of appointment of consultants to

conduct the study/analysis to ensure secure and reliable operation of national Grid, has

been under taken by CEA. A meeting to decide the data/inputs for the consultants was held

at CEA on 22.05.2015 under the Chairmanship of Member (GO &D), CEA.

Following issues pertaining to protection and system studies and actions required by RPCs

and constituents were discussed in the meeting:

(i) The Grid Study Committee will be chaired by Member (GO&D), CEA.

GM,NLDC, POSOCO will be the convener. MS RPCs will be the members. One STU

from each region would be nominated as member for the committee on rotational basis.

(ii) Identification of 25 nos of critical S/Ss in WR (already audited) for review of

protection audit and setting of protection relays thereof. The consultant would carry out

Protection Audit and review the protection philosophy adopted.

(iii) Substation wise protection audit reports in respect of all the substations audited in

the FY 2012-13.

(iv) Nomination of nodal officers from all power sector entities. A CE level officer

from each STU shall be appointed by each State/UTs to co-ordinate with SLDCs. Monthly

meeting will be held on VC.

The above information (at i, ii & iii) in the prescribed formats is required to be submitted

to CEA. The formats will be circulated after receipt of the same from CEA.

It was decided that from WR, CE, STU, MSETCL may be nominated for the grid study

committee for this year. Committee requested WRLDC to identify 25 critical S/s (already

Audited) of WR and forward to WRPC for onwards submission to Grid Study committee,

CEA. In respect of point (iv), it was decided that WRPC will take up utilities for

nomination of CE level officer from each utility.


Accordingly M/s Tractable was appointed as consultant. A meeting of WR constituents

was held on 12.08.2015 at WRPC, to collect the data required by the consultant. The

consultant M/s Tractable commenced the work under Task-I in August 2015. 256 S/S

protection audit reports were forwarded to M/s Tractable and they have completed the

scrutiny the protection audits reports for these S/Ss. The Task-II for review of protection

audit and protection relays thereof for 25 critical S/Ss commenced in December 15.



ITEM NO 8: COMMISSIONING OF NEW SYSTEM PROTECTION SCHEMES IN

CONNECTION WITH SYNCHRONIZATION OF SR AND NEW GRID

8.1: Back ground: As per NLDC’s letter dated 11.04.2014, the backing down quantum for

generators in WR were finalized for various security threats after NEW – SR

synchronization with 765kV Raichur-Sholapur Ckt-I. The matter was further deliberated in

the 26th WRPC meeting held on 21.06.2014 and decided that as and when the signals are

extended to the newer generators, the quantum of backing down of the already

participating generators will be reduced on prorate basis. NLDC vide letter dated 07th July

2014 communicated modification in SPS in view of commercial operation of 765kV

Raichur-Solapurckt-II.

8.2 :Revision in SPS : In anticipation of commissioning of 765kV Aurangabad-Sholapur

D/C and 765 kV Kolhapur-Narendra D/C and expected operationalization of additional

LTA/MTOA, NLDC vide letter dated 07th Sept. 2015 suggested revision in the SPS. The

implementation of this SPS was discussed in the meeting held on 16.10.2015 at WRPC

Mumbai. Further an Interim revision of the SPS subsequent to commissioning of 765kV

Aurangabad-Sholapur D/C was communicated by NLDC for implementation vide letter

dated 05.10.2015.

In the 30th WRPC meeting held on 24.11.2015, ED NLDC (POSOCO) stated that the

interim SPS scheme communicated vide letter dated 05.10.2015 have already been

implemented. He further informed that studies for revision of the SPS, with anticipation of

Narendra-Kolhapur line are being carried out and the revision of SPS considering these

lines would be informed shortly. With commissioning of 765kV Kolhapur-Kudgi (PG)

D/C (initially charged at 400kV), revision of SPS and the present status of implementation


of the SPS by various agencies involved was communicated by NLDC vide letter dated

23.12.2015(copy enclosed at Annex-8).

The modifications suggested are as follows:

Sr.No SPSname

(A)

ExistingSPSsettings(before

interimarrangement)

(B)

ExistingSPSaction

(C)

ProposedrevisioninSPS

(D)

ProposedSPSactionsinWR

(E)1 SPS-1

(Bothlinesinservice)

Totalflowon2*765kVSholapur-RaichurS/C>2500MWfor5secs.InS'pur-->Raichurdirection

800MWb/d.:JPL-150MW;JPLExtn-150MW,KSK-100MW,Lanco-100MW,DBPower-100MW,KWPCL-100MW,BALCO-50MW,NSPCL-50MW.

Totalflowon2*765kVSholapur-RaichurS/C>3500MWfor5secs.InS'pur-->Raichurdirection

800MWB/DinWR.-Alreadyimplemented.

2 SPS-1(Bothlinesinservice)

Totalflowon2*765kVSholapur-RaichurS/C>3000MWfor2.5secs.InS'pur-->Raichurdirection


Totalflowon2*765kVSholapur-RaichurS/C>4000MWfor2.5secs.InS'pur-->Raichurdirection


3 SPS-1(Onlyonelineinservice)

2*765kVSholapur-RaichurS/C>1500MWfor2.5secs.


2*765kVSholapur-Raichur>2000MWfor2.5secs.



765kVSholapur-RaichurS/C>1500MWinS'pur-->Raichurdirection-Instantaneous

Thissettingisalreadyblocked.


5 SPS-3 Lossof765kVS'pur-Raichurlinescarrying800MWtowardsSR

NoactioninWR Lossof765kVS'pur-Raichurlinescarrying1500MWtowardsSR

NoactioninWR

6 SPS-4 400kVRaipur-Wardhaeitherckt>850MWfor2.5secorTrippingofoneckt>=700MW


400kVRaipur-Wardhaeitherckt>850MWfor2.5secorTrippingofoneckt>=700MW

800MWb/d.:JPL-150MW;JPLExtn-150MW,KSK-100MW,Lanco-100MW,DBPower-100MW,KWPCL-100MW,BALCO-50MW,NSPCL-50MW.Alsoaddl200-300MWLSinWesternMaharashtra.

7 SPS-5 400kVWardha-Parlieitherckt>850MWfor2.5secorTrippingofoneckt>=700MW

800MWb/d.:APLTirora-200MW;Koradi-70MW,Chandrapur-250MW,Mauda-100MW,Khaparkheda-150MW,IB-30MW.


800MWb/d.:APLTirora-200MW;Koradi-70MW,Chandrapur-250MW,Mauda-100MW,Khaparkheda-150MW,IB-30MW.Alsoaddl200-300MWLSinWesternMaharashtra.

8 SPS-6 400kVParli-Sholapureitherckt>800MWfor2.5secorTrippingofoneckt>=700MW



800MWb/d.:JPL-150MW;JPLExtn-150MW,KSK-100MW,Lanco-100MW,DBPower-100MW,KWPCL-100MW,BALCO-50MW,NSPCL-50MW.Alsoaddl200-300MWLSinWesternMaharashtra.


765kVRaichur-SholapurS/C>800Ampsineitherdirectionfor10secs

Triptheline Thissettingisalreadyblocked.

NewSPS



-- ---- LossofimportatSholapuron765kVAurangabad-SholapurD/Cbymorethan2500MWduetotrippingoftheselines.

500-1000MWGenB/D:JPL-150MW;JPLExtn-150MW,KSK-100MW,Lanco-100MW,DBPower-100MW,KWPCL-100MW,BALCO-50MW,NSPCL-50MW.-TripBusreactorsat400kVParli(PG)&765kVPune(PG)


-- ---- Trippingofanyone765kVAurangabad-Sholapurcarrying>=1250MW

Trip240MVArBusReactorat765kVSholapur(PG)and63MVArBusReactorat400kVSholapur(PG).

MS WRPC enquired as to whether the interim SPS has been implemented and

whether the proposed SPS and actions at (D) and (E) are to be implemented.

WRLDC representative stated that the interim arrangement suggested by NLDC

have been implemented in WR and the proposed revision in SPS (D) and proposed

SPS actions (E) would be reviewed once all the down stream network in SR is

established, since the proposed SPS and actions are subject to establishment of the

envisaged down stream network in SR. The down stream network in SR system is yet

not completed and therefore this scheme may be revised by NLDC in future.

WRLDC representative further stated that with commissioning of 765kV

Aurangabad-Sholapur D/C, the proposed SPS-8 for “loss of import at Sholapur on

765kV Aurangabad-Sholapur D/C by more than 2500MW due to tripping of these

lines” needs to be implemented as an interim arrangement for generation backing

down without tripping the Bus reactors at 400kV Parli and 765kV Pune S/Ss. PGCIL

was requested to implement the SPS-8 and extend signals to generators listed in the

proposed actions (E).

Committee noted.

8.3: Non receipt of SPS signals :


Back ground : In the 479th OCC meeting, WRLDC intimated that on 02.01.2016, between

0700 hrs to 0710 hrs, SPS condition of flow on 765 kV Sholapur-Raichur D/C carrying

2500 MW for 5 sec was satisfied. However there was no load shedding in SR or

generation reduction at JPL, JPL Extension, KSK, NSPCL, KWPCL, DB Power, LANCO,

BALCO. It was understood that SPS signal was generated from 765kV Solapur Station but

not received by Raipur station. The generating stations of WR have also informed that the

SPS signal was not received from Raichur/Solapur. Similarly signal was not received at

Kolar. Again on 02.01.2016 765 kV Solapur-Raichur-II tripped at 10:46hrs causing

overloading in circuit-I. SPS condition was also again satisfied (Single circuit flow

exceeded 1500 MW for more than 2.5 secs). In this case also no SPS action by WR

Generators and load loss by SR constituents was reported.

POWERGRID representative stated that on 02.01.2016 out of the 3 redundant

communication channels/PLCC BSNL and Reliance links were down. The third

communication channel (PLCC) is from Raichur to Raipur via Kolar, however on

02.01.2016, there was problem at Kolar end and therefore the SPS signal was not

received at Raipur.

He further informed that on 23.01.2016 the signals were successfully received on

operation of the SPS.

Committee noted.

ITEM NO 9: IMPLEMENTATION STATUS OF SPS

9.1-a) SPS for 765 kV Bina – Gwalior – Agra: An SPS has been implemented for Bina –

Gwalior– Agra D/C, wherein when sudden reduction in import by NR on Agra-Gwalior I&

II ckts by more than or equal to 1500MWs, 500 MWs generation back down in WR

(KSTPS NTPC– 120 MWs, VSTPS NTPC – 200 MWs & CGPL – 180 MWs) and load

shedding in NR would take place.

9.1-b) Revision of SPS : NLDC vide letter dated 07th Sept. 2015 intimated that with

commissioning of 765kV Gwalior-Phagi D/C & 765kV Phagi-Bhiwani, the SPS margin of

1500MW on 765kV Gwalior-Agra D/C was increased to 3000MW. Generation backing

down quantum in WR increased from 500MW to 1000MW. In addition to NTPC KSTPS,

NTPC-VSTPS &CGPL stations, SASAN UMPP has also been included in the SPS for a

total backing down quantum of 1000MW. In the meeting held on 16.10.2015, it was


intimated that the sensitivities of these generators to Agra-Gwalior flow is same. Further

the communication signal for the SPS is required to be extended to SASAN UMPP by

POWERGRID by procuring the end equipments. The same was discussed in the 30th

WRPC meeting wherein it was decided that till the communication signal is extended to

SASAN UMPP and SASAN UMPP is ready for generation backing down of 250MW, all

the other stations i.e. NTPC KSTPS, NTPC-VSTPS & CGPL would wire up 330MW each

backing down quantum for this SPS.

NTPC-VSTPS vide letter dated 23.12.2015 have intimated that they have wired up

250MW backing down quantum.

POWERGRID & SASAN UMPP vide letter dated 10.11.2015 was requested to expedite

the extension of communication signal and wire up 250MW backing down quantum

respectively.

The matter was perceived with these utilities vide letters dated 02.12.2015 &

08.01.2016 (copy enclosed at Annexure 9.1b) by WRPC.

NTPC representative stated that the 330MW backing down quantum has been

implemented at NTPC-VSTPS and 250MW at NTPC-KSTPS.

CGPL representative stated that the backing down quantum implemented at CGPL

is 180 MW. He further informed that the technical minimum of their units is around

400MW-450MW and the units become highly instable if the loadings of the units are

reduced further. Therefore he requested that they may be allowed to incorporate

additional condition viz “when the generation is above technical minimum and the

backing down quantum will not push the loading on the generator below technical

minimum”, for backing down of 330MW. With incorporation of the above condition

they would wire up the quantum immediately.

Committee appreciated the concerns of CGPL and the request of CGPL was

accepted. On 03.02.2016 CGPL representative informed that they have wired up

330MW backing down quantum for this SPS with the additional condition that the

generation is above technical minimum.

POWERGRID representative stated that another 6 months would be required to

extend the signal to SASAN, since the end equipment procurement process has just

now been initiated.


Committee noted the above and requested PGCIL to expedite the extension of signal

to SASAN and ensure readiness of SASAN for the backing down quantum of

250MW. Till the signal is extended to SASAN, the backing down quantum at NTPC-

KSTP would be 250MW, NTPC-VSTPS would be 330 and CGPL would be 330MW

and after extension of signal to SASAN and readiness of SASAN the backing down at

NTPC-KSTPS, NTPC-VSTPS, CGPL and SASAN would be 250MW.

9.1-c) Mock testing of SPS : WRLDC vide letter dated 03.11.2015 & 27.11.2015 have

intimated that the mock testing of SPS for 765 kV Bina – Gwalior – Agra D/C was carried

out on 29.10.2015 & 26.11.2015and the signals were successfully received at NTPC

KSTPS, NTPC-VSTPS & CGPL.

Committee noted.

9.1-d) Auto tripping of 220kV Gwalior-Malanpur#1&2 on tripping of 765kV Gwalior

Agra#1&2 on 14.01.2016 : WRLDC vide letter dated 14.01.2016 (copy enclosed at

Annexure-9.1-d1) have intimated that during tripping of 765kV Agra-Gwalior 1 & 2 on

14.01.2016 at 07:14hrs & 07:32hrs, 220kV Gwalior-Malanpur D/C also tripped on SPS

operation. However as per discussions of meeting held on 16.10.2015 it was suggested to

block the tripping of 220kV Gwalior-Malanpur D/c in the event of tripping/reduction of

import by NR on 765kV Agra-Gwalior 1&2 by more than or equal to 300MW. Powergrid

vide letter dated 15/18th Jan 2016(copy enclosed at Annexure-9.1-d2) have intimated that

the tripping of 220kV Gwalior-Malanpur #1&2 on tripping of 765kV Gwalior-Agra #1&2

and operation of the SPS have been blocked.

WRLDC representative stated that the relief obtained on operation of SPS on

14.01.2016 was not as per the designed 250MW at NTPC-KSTPS, NTPC-VSTPS and

CGPL and requested that the generators give the explanation.

NTPC representative stated that the generation at NTPC-KSTPS and NTPC-VSTPS

was very low during the operation of SPS. CGPL representative stated that the

generation was at technical minimum during the operation of SPS.

Committee noted.


9.2) SPS at 400kV Vapi S/s letter modified for 220kV Vapi-Kharadpada D/C

overloading: The SPS for Vapi ICT O/L was discussed in a special meeting held on

03.09.2013 at TAPS 3 & 4 and further finalized in the meeting held on11.04.14 between

GETCO, DD & DNH representatives i.e. restrict loading on 3 X 315 MVA 400/220 kV

ICTs at Vapi (PG).

The SPS was further discussed in the OCCM and it was felt that due to

commissioning of 400kV Kala S/s, the ICT overloading at Vapi was not so critical,

therefore the scheme needs to be revised.DNH vide letter No-11(739)/ELE/2013/3382

dated 30.09.2014 have requested that the conditions earlier envisaged (ICT overloading at

Vapi) for SPS may be modified such that load shedding shall take place in DD & DNH

system by sensing the overloading/tripping of 220kV Vapi-Kharadpada D/C lines.

In the 124th PCM, GETCO representative intimated that as per MoM of 122nd PCM, the

SPS was modified i.e. considering 220 kV Vapi – Kharadpada D/C over loading instead of

ICT O/L.

In 125th PCM, GETCO representative intimated that smart meters for load shedding have

been procured and handed over to DNH.

DNH vide letter dated 16.11.2015 (copy enclosed at Annexure-9.2) have intimated that

the SPS has been commissioned on 04.10.2015

Committee noted.

ITEM NO 10: ISLANDING SCHEMES:

10.1) KAPS: In pursuance with the decision of special meeting held on 03.09.2013 at

TAPS 3 & 4, SLDC GETCO and KAPS have formulated the islanding for KAPS. The

scheme was discussed in 121st PCM and finalized in 122nd PCM.

In 121st PCM it was intimated by KAPS representative that main under

frequency relay (MICOM-P-941 numerical relay) would be purchased by KAPS for Vapi

Sub-station, since the existing FCX relay is defective. GETCO agreed for procurement of

other auxiliary relays and wiring of the same. GETCO informed that they have planned for

PLC based islanding scheme and in near future the same would be incorporated in the

Islanding scheme.

In 123rd PCM, GETCO representative intimated that the implementation of islanding

scheme is under progress. KAPS representative intimated that the U/F relay is under

procurement stage.


KAPS representative stated that islanding scheme has been commissioned, however it

has not been taken into service, since the links for Vapi loads have not been made

through. GETCO representative stated that the links shall be made through and the

islanding scheme shall be taken into service.

Committee noted.

10.2) Islanding scheme for Sugen: In the 124th PCM, WRLDC representative intimated

that a meeting was held at WRLDC, Mumbai on 16.04.2015 to finalize the islanding

schemes of Sugen.

i) Islanding of Sugen: The islanding of SUGEN (Sugen generation – 2 X 387.5 MWs)

with Surat load was designed and is as follows.

1. 48.5 Hz : 220 kV Sugen-Kim D/C will be tripped

2. 48.4 Hz: Load Generation Balance to be monitored with respect to 220 kV feeders

for Surat city and generation at Sugen.

3. 48.2 Hz: 400 kV Sugen-Pirana, 400 kV Sugen-Vapi (PG) to be opened in first

Phase one by one. Fine tuning of frequency would be intimated by Sugen at the time of

implementation.

4. 48.0 Hz: 400 kV Sugen-Unosugen and 400 kV Sugen-Gandhar have to be opened

in next phase one by one resulting in islanding of Sugen with Surat Load. Fine tuning of

frequency would be intimated by Sugen at the time of implementation.

5. 47.5 Hz: Instantaneous tripping of Units.

It was also decided that while synchronizing the Island with the grid, island has to be

connected with 220 kV Sugen – Kim D/C (for extending supply to GSEG, Utran S/s).

GETCO agreed to provide necessary synchronizing facilities at 220kV Kim S/s.

GETCO representative intimated that it has already provided necessary synchronizing

facilities at 220 kV Kim S/s.

In the 125th PCM, M/s Sugen was requested to implement the above proposed island

scheme at the earliest.

Since, Sugen representative was not present for the meeting the status could not be

updated.

Committed noted.


10.3) Islanding schemes for TAPS 1 & 2 and TAPS 3 & 4: In the 124th PCM,WRLDC

representative intimated that a meeting was held on 16.04.2015 at WRLDC, Mumbai to

discuss and finalize the islanding schemes for TAPS-1&2 and TAPS 3&4. In the meeting,

it was decided that TAPS 1 & 2 generation be islanded with Bhilad load. The generation

capacity of TAPS 1 & 2 is 320 MWs (2 X 160 MWs) and the load at Bhilad S/s is radial

load and is of around 90 – 140 MWs.

The islanding scheme for TAPS 3 & 4 with load of Boisar (MSETCL) is

under discussion stage. In the 124th PCM, Committee reviewed the proposal and opined

that units of TAPS 1 & 2 are very old and fine control of generation is not possible. The

governors of TAPS 1 & 2 are such that the generation can either be 160 or 100 MWs.

Further the radial loads at Bhilad are variable and fine control of loads may not be

possible. Therefore islanding TAPS 1 & 2 with Bhilad load may not survive for long and

even if it survives, while restoring the grid it may be very difficult to synchronize this

island with grid as both load and generation of the island are not controllable.

Further it was felt that as the generation of TAPS 3 & 4 can be controlled, it

would be better to form an island with generation of TAPS 1, 2, 3 & 4 and loads of Bhilad

and Boisar. Committee requested TAPS 1 & 2 to take up the above proposal with higher

authorities and revert back to the PCM forum with its proposal.

TAPS 1&2 vide letter dated 12.05.2015 have send their comments on the proposed

islanding scheme for TAPS 1& 2.

TAPS 1 & 2 representative intimated that the above proposal was discussed in depth with

higher authorities. It was felt that TAPS 1, 2, 3 & 4 together as island have multiple

combinations (All Units are running, TAPS 1 under shutdown etc..,) , it would be very

difficult to implement the logic for the same.

In the 125th PCM it was decided to drop the proposal for islanding of TAPS 1 & 2 and

islanding scheme for TAPS 3&4, be formulated and requested to prepare a draft scheme

and put up the same in the next PCM.

In the 29th WRPC meeting held on 24.07.2015 at Aurangabad, GM WRLDC informed that

they have prepared the scheme after discussion with TAPS 1&2 and 3&4 authorities. All

data for preparation of an islanding scheme exists. He requested NPCIL to formulate any

suitable islanding scheme, in case they do not wish to implement the present scheme for

Taps islanding and put up to PCM. Since necessary data was available with NPCIL from

the above discussions it was decided that Taps1&2 and Taps3&4 may examine the

schemes and revert to PCM forum. MS WRPC requested NPCIL to look into the islanding


schemes and suggest a suitable islanding scheme. Necessary regulatory clearances if any,

may also be obtained. NPCIL agreed to revert back in PCM.

Committee suggested that till NPCIL comes with the fresh SPS proposal, the issue

shall be closed.

ITEM NO. 11: FOLLOW UP ITEMS:

11.1: AUFLS Quantum & Stages

A. Back ground: In the 2ndNPC meeting held on 16.07.2013 at Delhi, four (4) stages

of automatic under frequency relay operation starting from 49.2 was approved.CEA vide

letter No.8/X/MMS/Gm-13/1007-1012 dated 06.08.2013, have intimated that the

implementation of load shedding for all the four stages (i.e. 49.2, 49.0, 48.8 and 48.6Hz.)

be taken up and completed by 22.10.2013.The updated status of quantum implemented for

AULFS and df/dt as on 30.11.2015 is as follows.

AUFLS implementation status in WR as on 31.03.2015

(all figures are in MWs) 49.2 Hz 49.0 Hz 48.8 Hz 48.6 Hz Actual Target Actual Target Actual Target Actual Target

Gujarat Average 773 580 726 580 1117 580 1025 590 MP Average 468 460 450 460 460 460 465 465 Chattisgarh Average 110 150 114 150 117 155 91 155 Maharashtra Average 1122 805 1215 810 1044 815 1071 820 Goa Average 25 25 25 25 25 25 25 DD Average 10 10 15 15 16 15 15 15 DNH Average 30 30 30 30 35 35 35 35 Total 2513 2060 2575 2070 2814 2085 2727 2105

df/dt implementation status in WR

(all figures are in MWs) 49.9 Hz & 0.1 Hz / Sec

49.9 Hz & 0.2 Hz / Sec

49.9 Hz & 0.4 Hz / Sec

Actual Target Actual Target Actual Target Gujarat Average 0 1006 1454 905 1610 1001 MP Average 475 361 415 355 445 392 Chattisgarh Average 120 27 40 37 40 120 Maharashtra Average 370 546 1131 621 522 686 TPC (Tata Power) Average

60 60 82 82 273 273

Totalrelief

1025 2000 3122 2000 2890 2472


Gujaratadditionaldf/dtsettingat49.9Hz&0.3Hz/sec=399MW

TPCadditionaldf/dtsettingat49.9Hz&0.5Hz/sec=931MW

All the constituents were requested to give the list of the feeders connected to UFRs

in a soft copy (excel sheet) within 15 days along with other details like peak load (MWs),

average load (MWs), kV, substation etc., Utilities were also requested to furnish the details

of df/dt relays to WRPC in soft copy.

The implementation of AUFLS for df/dt and flat frequency was discussed in the 4th

NPC meeting held on 10.12.2015 at New Delhi and NPC have mandated that at least 20%

of the under frequency relays installed in the region should be inspected by RPCs in each

year, besides self certification of healthiness of the UFRs. Further NPC has sought details

of the UFR installed at S/S feeders (i.e mapping of the UFR) along with the Average /peak

demand of the feeders.

MSETCL, GETCO, MP & Chhattisgarh have submitted the data for UFR relays in

2014. UFR data from DD&DNH is still not received. None of the utilities have submitted

list of feeders connected to df/dt relays.

In view of the decision of 4th NPC all States/Utilities were requested to submit

updated details of the feeders where UFR and df/dt have been installed along with its

healthiness, peak load & average load of the feeder.

SE(P) WRPC stated that in the 4th NPC meeting, the NPC as regards to the

stage –I (49.9 Hz & 0.1Hz/sec) setting have suggested that the regions may take a call

on the setting of this stage, since this stage is vulnerable for sudden loss of generation

or any grid disturbance. The rate of fall of frequency would vary from one location to

another and therefore there could be no uniform setting of df/dt relays in different

regions. In view of this, NPC decided that the settings would be determined by each

RPC separately after detailed study of load & generation balance in different areas of

the region and communicate the same to the NPC for ratification. Further

Chairperson NPC, keeping in view the manpower constraints in RPC secretariats,

suggested that instead of inspection of one-third number of total relays in a region, at

least 20% of the under frequency relays installed in the respective regions should be

physically inspected by the respective RPCs in each year besides self-certification by

STUs.

The self certification by the STUs regarding healtiness of the UFRs be done as per the

procedure/checklist enclosed at Annexure-11.


Committee discussed the above and decided that the targets under stage-I (i.e. 49.9Hz

& 0.1 Hz/sec) be proportionally adjusted to the targets under Stage-II(i.e. 49.9Hz &

0.2 Hz/sec) & Stage-III(i.e. 49.9Hz & 0.4 Hz/sec). The revised actual implemented and

target table for df/dt would be as follows;

df/dt implementation status and targets in WR

(all figures are in MWs) 49.9 Hz & 0.1 Hz / Sec

49.9 Hz & 0.2 Hz / Sec

49.9 Hz & 0.4 Hz / Sec

Actual Target Actual Target Actual Target Gujarat Average 0 0 1454 1383 1610 1529 MP Average 475 361 415 355 445 392 Chattisgarh Average 120 27 40 37 40 120 Maharashtra Average 370 546 1131 621 522 686 TPC (Tata Power) Average

60 60 82 82 273 273

Totalrelief

1025 2000 3122 2478 2890 3000

Gujaratadditionaldf/dtsettingat49.9Hz&0.3Hz/sec=399MW

TPCadditionaldf/dtsettingat49.9Hz&0.5Hz/sec=931MW

Committee requested Constituents/Utilities to confirm/ensure the implemented

quantum. Further Committee recommended that the self certification in respect of

the relays under their jurisdiction be done by the STUs every half year, regarding

healthiness of the UFRs, as per the procedure/checklist enclosed at Annexure-11

11.2: Status of Bus Coupler and Bus Bar protections at S/s.

Back Ground: In the 118th PCM, Chairman TCC stated that the Bus Bar protection

schemes should be implemented by the respective utility, without expecting the funding

under R&U from MoP, GoI.In 121st PCM,WRLDC informed that BB protection at 7 Nos

of 220kV S/Ss (Single Bus S/Ss) in GETCO system, 3 Nos of 220kV S/Ss in MSPGCL

system, 7 Nos of 220kV S/Ss in MPPTCL system & 5 Nos of 220kV S/Ss in CSPTCL

system was pending.

In 123rd PCM, GETCO representative intimated that out of 7 substations,

BB protection was commissioned at 5 substations. At Limbdi substation it is under

commissioning stage & expected to be completed by May, 2015 and at Navsari substation,


it is in tendering stage. MPPTCL representative intimated that BB protection relays were

procured and commissioning is under progress.

The updated status given by constituents is as follows;

1) Non Availability of Bus Bar protection at 220/132 kV Bhatapara S/s:CSPTCL

representative intimated that busbar protection is under tendering stage.

2) Status of Bus Bar protection Scheme at 220/66 kV Magarwada S/s: It was

informed that the 220kV BB protection at Magarwada S/S is in service.

3)Bus Bar protection at 400/220 kV Korba West S/s: Regarding LBB/Bus Bar protection at

400/220 kV Korba West, 200/132 kV Korba East and 220 kV Korba East Extension,

CSPTCL representative intimated that busbar protection has been installed at 400/220 kV

Korba West S/s & it is under testing. He also intimated that busbar protection relay

procured for Korba east extension.

Committee noted.

ITEM NO. 13: OTHER ITEMS

ITEM NO. 13.1: Reliance Proposal for 2 out of 3 df/dt scheme for Islanding:

Reliance representative stated that the load shedding in existing Islanding scheme is based

on single UFR measurement. However to ensure reliability of the UFR based load

shedding schemes in the Island, Reliance intends to implement the logic of two out of

three for initiation of Load shedding in their system.

The presentation given by Reliance is enclosed at Annexure-13.1.

Committee discussed the scheme and observed that the two out of three logic

increases the redundancy and their by increases the reliability of the UFR based load

shedding. Therefore Reliance may implement the scheme given in the presentation in

their system.

ITEM NO. 13.1: Distance Protection Scheme settings at APL end on 400kVMundra-

Sami lines 1 & 2 :

PGCIL representative stated that FSC is installed on 400kV Mundra-Sami 1 & 2. However

the DPS provided on the lines have not been set by factoring the FSC, this may result in

over reaching of the DPS schemes and therefore APL may factor in FSC, in the settings of

the distance protection schemes.


APL representative stated that they are studying the mutual coupling effect on zero

sequence components during the faults and after detailed study they would come up in the

next PCM.

Committee suggested that the practice used by PGCIL in the relay setting of lines

having FSC be adopted by APL for time being and as & when the study by APL is

completed the same shall be shared by APL in the PCM for further discussions.

ITEM NO. 13: DATE AND VENUE OF THE NEXT MEETING

Committee decided that the next PCM (127th PCM) would be held in April 2016.

*******

Sl.No. Name Designation Organisation E-mail Mobile No.

1 Shri P.A. Amillsanthwar Dy. C.E. MSPGCL [email protected] 94224985012 Shri S.P. Vasekar S.E. TCC, Nasik [email protected] 77680002223 Shri A.V. Deo S.E. MSETCL [email protected] 85549932904 Shri D.K. Rokade S.E. MSETCL [email protected] 91678315515 Shri M.S. Jangde S.E. MSETCL [email protected] 85549933896 Shri J.R. Kulkarni S.E. MSETCL [email protected] 90309649007 Shri V.R. Katrale E.E. MSETCL [email protected] 85559950208 Shri D.J. Kolhe E.E. SLDC, Kalwa [email protected] 98209811159 Shri R.S. Alone E.E. Koradi [email protected] 9423117108

10 Shri A.R. Naik E.E. MSETCL [email protected] 976947455011 Shri Dogargaonkar H.D. MSETCL [email protected] 703096493612 Shri D.P. Nandanwar A.E.E. MSETCL [email protected] 796950979813 Shri K.D. Kumar S.E. SLDC, GETCo. [email protected] 992520872714 Shri S.A. Patel S.E. GETCo. [email protected] 992521104115 Shri K.G. Patel D.E. GSECL [email protected] 992521097716 Shri S.P. Soni E.D. MPPGCL [email protected] 942580655017 Shri P.C. Soni S.E. MPPGCL [email protected] 942580655218 Shri R.C. Sharma E.E. MPPGCIL [email protected] 942580497019 Shri P.S. Raghav E.E. MPPTCL [email protected] 942580499820 Shri H.C. Surma A.E. DNH [email protected] 982415404421 Shri Uday Trivedi A.V.P. APL [email protected] 909905505422 Shri Mohan R. Waingankar D.G.M. Reliance Infra [email protected] 932421666423 Shri Girish Jawale Team Head Tata Power [email protected] 922331141924 Shri K.N. Athavale Head EMD CGPL [email protected] 922729535825 Shri Subhash Limbani NPCIL [email protected] 942882152026 Shri R.S. Arekar SO/D NPCIL [email protected] 942163380627 Shri P.C. Huddar Addl.G.M. NSPCL [email protected] 942523406328 Srhi Prashant Gupta RGPPL [email protected] 942200695529 Shri P. Sreenivas G.M. NTPC [email protected] 900467757330 Shri D. Roy Chowdhury A.G.M. NTPC [email protected] 942522209431 Shri A.K. Chandeliya D.G.M. NTPC [email protected] 900449715132 Shri Kuleshwar Sahu PGCIL [email protected] 942529421433 Shri Abhimanyu Gartia D.G.M. WRLDC [email protected] 986908805834 Smt. Pushpa Seshadri C M WRLDC [email protected] 986940448235 Shri Ravi Wadyalkar, Mgr. PGCIL [email protected] 942376254736 Shri Chandan Kumar Engr. WRLDC [email protected] 986925146037 Shri Ankit Vaish Dy. Mgr. PGCIL [email protected] 9409305725

LIST OF PARTICIPANTS OF 126th PCM MEETING HELD ON 02.02.2016 & 03.02.2016 AT WRPC, Mumbai

kanchigupta

Text Box

ANNEX 1

38 Shri S.D. Taksande M. S. WRPC [email protected] 982087838439 Shri Satyanarayan S. S E (Comml.) WRPC [email protected] 922339993840 Shri P.D. Lone E E (Comml.) WRPC [email protected] 986762282341 Shri Vikas Mundotia A.D. -I WRPC [email protected] 901102257742 Ms. Kanchi Gupta A.D. -I WRPC [email protected] 8879583067

WRLDC, Mumbai Page | 1

Detailed report on the occurrence at Akrimota, Gujarat on 6th July 2015 1. Event Category : GD-1

2. Event Date and Time : 6th July 2015, 11:13 Hrs

3. Event Summary: Due to Bus fault at Akrimota sub-station, its bus bar protection operated and tripped

both the 220 kV Bus causing tripping of all the elements. This has resulted in loss of 125 MW

generation at Akrimota and 100 MW load loss in the Akrimota, Jamanwada and Panadero area.

Figure 1 : Geographical Network Diagram (Source: GETCO)

4. The antecedent conditions

The antecedent conditions at 11:10 Hrs Hrs for the incident are given under as per WRLDC SCADA data:-

NEW Grid Frequency: 49.95 Hz.

WR Demand Catered : 38921 MW

WR Total Generation : 42674 MW

Gujarat Demand Catered: 12080 MW

Gujarat Own generation : 9084 MW

Gujarat Drawl from Grid : 2996 MW

5. Event Overview:

Prior to the event the data from Akrimota (AKLTPS) and KLTPS were not getting updated at

WRLDC.

At 11:13 Hrs, Bus fault occurred at Akrimota sub-station due to which its bus bar protection has

operated. As there is no detailed submission from Akrimota over the incidence, so the type and

nature of bus fault could not be determined.

HCL

Typewritten text

Annex 2.05


With the fault, all the lines from Akrimota i.e. 220 kV Akrimota-Jamanwada (LILO of Akrimota-

Jamanwada one ckt), Akrimota-Nakhatarana and Akrimota-KLTPS circuit has tripped causing

blackout at the Akrimota station.

Further, both the generating Unit of Akrimota (125 MW each) has tripped in the event on bus bar

protection operation causing a generation loss of around 125 MW.

Gujarat SLDC has intimated about load loss during the event in the AKLTPS, KLTPS and Jamanwada

area which was around 100 MW.

From the drawal of Gujarat, it was found that effective loss of 72 MW gen loss has occurred as

the drawal has increased by this quantum.

Figure 2: Gujarat drawal and Frequency during the event.

Table 1 : The sequence of tripping and restoration

Sl No.

Name of the transmission element/ Unit

Time of Tripping

(hh:mm:ss.000)

Relay indication End

1

Relay Indication

End 2

Time of restoration

(hh:mm)

1 220 kV Bus 1 Akrimota 11:13 Bus bar operation 11:56

2 220 kV Bus 2 Akrimota 11:13 Bus bar operation No details

3 220 kV Akrimota-

Nakhatarana 11:13:07.918

Bus bar

operation No Details 11:56

4 220 kV Akrimota-

Jamanwada 11:16:07.093

Bus bar

operation No Details No Details

5 220 kV Akrimota-KLTPS 11:13:08.284 Bus bar

operation No Details 12:24

6 125 MW AKLTPS Unit 1 11:13 Bus bar operation 19:52

7 125 MW AKLTPS Unit 1 11:13 Bus bar operation 17:51

(Details from SOE/Site)


Load / Generation affected: Generation loss of 125 MW and load loss of 100 MW occurred during the

event. This is as per information received from Gujarat SLDC.

Frequency Change : No significant change in ferquency has been observed during the event.

Restoration: Restoration of element is done as per the given sequence in table 1.

6. Analysis: Due to lack of details from the SLDC Gujarat and generating station, the event could not be

analysed in detail. Gujarat SLDC and AKLTPS may present the event analysis during the next PCM

meeting.

7. Protection standard Issues:

Issues Protection clause applicable Agency

Non-submission of Preliminary Report from User, STU,CTU,SLDC to RLDC

1. IEGC 5.9.6.a 2. CEA Grid Standard 12.2 (Applicable for SLDC,ALDC only)

Gujarat SLDC

DR/EL not provided within 24 Hours

1. IEGC 5.2 (r) 2. CEA grid Standard 15.3

Gujarat SLDC/ AKLTPS

Non-Submission of Details for the tripping which is required for appropriate analysis for GD/GI

1. IEGC 5.2 (r), 5.9.6.c (VI) 2. CEA grid Standard 15.3 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6. 4.d

Gujarat SLDC/ AKLTPS

SCADA data non-availability for the station

1. IEGC 4.6.2 Data and Communication Facilities 2. IEGC 5.2.q

Gujarat SLDC

8. Remarks:

The event analysis in the above incident could not be done in absence of the detail from the sub-station.

It can be seen that both the buses have tripped during the event, which is not normally observed in case

of bus fault. Gujarat SLDC is requested to get the desired analysis report from AKLTPS for presenting the

same in the Next Protection committee meeting. Further if any abnormality or protection mis-operation

is observed at site then the same may kindly be corrected urgently. Gujarat SLDC may kindly inform

AKLTPS to submit the details of any GD/GI in future as soon as possible to SLDC.

Yours truly,

Abhimanyu Gartia

Dy. General Manager (MO-II & III & LO)

Date Time Date Time

1 400kV JABALPUR-ITARSI 3 01-05-2015 6:38 1.5.15 7:10 A/T on Y-E due to burning of crop waste

2 400kV JABALPUR-ITARSI 4 01-05-2015 6:38 1.5.15 7:10 A/T on Y-E due to burning of crop waste

3 400kV BHACHAU-RANCHHODPURA 202-05-2015 16:39 2.5.15 17:12A/T on R-E (AR attempted fault came again in reclaim

time)

4 400kV BHACHAU-RANCHHODPURA 302-05-2015 16:39 2.5.15 17:12A/T on R-E (AR attempted fault came again in reclaim

time)

5 ICT1 DEHGAM 400/220kV 03-05-2015 9:30 4.5.15 19:07A/T on Y-B fault caused due to jumping of monkey at

Tertiary side (Near Horn Gap).

6 ICT1 DEHGAM 400/220kV 03-05-2015 9:30 4.5.15 19:07A/T on Y-B fault caused due to jumping of monkey at

Tertiary side (Near Horn Gap).

7 400KV SINGAJI -PITHAMPUR - I 04-05-2015 16:39 04.05.15 20:43 YESLine tripped due to R Phase ground fault, Dist. 73.02 Km

from Singhaji end, Z-I optd.

8 400KV SINGAJI - PITHAMPUR - II 04-05-2015 16:39 04.05.15 20:52 YES Line tripped on E/F

9 400kV SASAN-JABALPUR 07-05-2015 19:03 7.5.15 20:05 A/T on Y-E persisting fault

10 400kV SASAN-JABALPUR 07-05-2015 19:03 7.5.15 20:05 A/T on Y-E persisting fault

11 220KV SARNI S/S ICT. NO.I 08-05-2015 14:00 08.05.15 15:40 NOLine tripped due to `B` phase overcurrent, PAT, PE, PSW

optd.

12 220KV SARNI S/S ICT. NO.2 08-05-2015 14:00 08.05.15 15:40 NOLine tripped due to `B` phase overcurrent, PAT, PSW, PS-

III, PS-III, E/F optd.

13 400kV KHANDWA-DHULE 1 09-05-2015 22:48 10.5.15 19:09 A/T on Y-E fault due to insulator flashover

14 400kV KHANDWA-DHULE 2 09-05-2015 22:48 10.5.15 19:09 A/T on Y-E fault due to insulator flashover

15 220 KV BRS-SHUKHA 09-05-2015 13:38 09.05.15 14:00 YESLine tripped due to À` phase fault, Z-II, A/R lockout

optd.

16 220 KV BRS-SHUKHA 09-05-2015 14:26 09.05.15 18:29 YESLine tripped due to À` phase fault, Z-II, A/R lockout

optd.

17 400kV VINDHYACHAL-SATNA 1 10-05-2015 12:07 10.5.15 12:07A/R successul at Satna end (due to transient fault) failed

at Vindhyachal end

18 400kV VINDHYACHAL-SATNA 1 10-05-2015 12:07 10.5.15 12:07A/R successul at Satna end (due to transient fault) failed

at Vindhyachal end

19 400kV VINDHYACHAL-SATNA 1 13-05-2015 13:35 28.5.15 22:33A/T on Y-E fault due to tower collapse at location no.

708

20 400kV VINDHYACHAL-SATNA 2 13-05-2015 13:35 28.5.15 22:59A/T on R-E fault due to tower collapse at location no.

708

21 765kV SATNA-BINA 1 13-05-2015 16:06 13.5.15 16:57A/T on R-E fault (AR attempted, fault came again in

reclaim time)

22 400kV GANDHAR-DEHGAM 2 13-05-2015 23:24 14.5.15 0:48A/R successful at Dehgam end only on Y-E transient

fault but failed at Gandhar end

23 400kV VINDHYACHAL-SATNA 1 13-05-2015 13:35 28.5.15 22:33A/T on Y-E fault due to tower collapse at location no.

709

24 400kV VINDHYACHAL-SATNA 2 13-05-2015 13:35 28.5.15 22:59A/T on R-E fault due to tower collapse at location no.

709

25 765kV SATNA-BINA 2 13-05-2015 16:06 13.5.15 16:57A/T on R-E fault (AR attempted, fault came again in

reclaim time)

26 400KV SINGAJI - JULWANIA 14-05-2015 18:57 14.05.15 19:46 YESLine tripped due to B- Phase fault, Z-I optd. Dist. 43.68

Km from Singhaji end,

27 220kV KAWAS-NAVSARI(GIS) 1 15-05-2015 17:28 15.5.15 18:09 A/T on R-E due to snapping of earthwire

28 220kV KAWAS-NAVSARI(GIS) 2 15-05-2015 18:43 15.5.15 19:29 A/T on R-E due to snapping of earthwire

29 400kV NAGDA-DEHGAM 1 15-05-2015 19:17 15.5.15 19:17 A/R successful on Y-E transient fault

30 220 KV AMK-BRS FDR. No.3 15-05-2015 10:21 15.05.15 10:44 YES Line tripped due to À` phase fault, Z-I optd.

31 220 KV BRS-AMK FDR. No.II 15-05-2015 10:15 15.05.15 10:40 YES Line tripped due to A, B phase fault, Z-I, DPR optd.

32 765kV SATNA-BINA 1 16-05-2015 14:14 26.5.15 2:36A/T on Y-B fault due to collapse of tower during

localized whirl wind and stormy weather conditions.

33 400kV SATNA-BINA 1 16-05-2015 14:14 17.5.15 18:55 A/T on R-E persisting fault due to snapping of E/W

34 220 KV AMK-SIDHI FDR. 16-05-2015 12:02 16.05.15 12:37 YES Line tripped due to `B` & `C` phase fault, Z-I optd.

35 220 KV BRS-SATNA 16-05-2015 13:40 16.05.15 14:12 YES Line tripped due to `BCN` phase fault, Z-I, Dist. 166 Km.

36 220 KV AMK-PANAGAR FDR. 18-05-2015 12:14 18.05.15 12:34 YES Line tripped due to À-N` phase fault, Z-I optd.

37 765kV AGRA-GWALIOR 1 19-05-2015 16:18 19.5.15 16:27A/T on R-E persisting fault during high speed whirlwind

along with gale storm

38 765kV AGRA-GWALIOR 2 19-05-2015 16:18 19.5.15 16:47A/T on R-E persisting fault during high speed whirlwind


39 765kV SATNA-GWALIOR 2 19-05-2015 19:07 20.5.15 0:14A/T on Y-E persisting fault during high speed whirlwind


40 220 KV AMK-JABALPUR FDR. No.2 19-05-2015 12:57 19.05.15 13:15 YES Line tripped due to `C-N` phase fault, Z-1 optd.

41 220 KV AMK-BRS FDR. No.2 19-05-2015 14:22 19.05.15 17:02 YES Line tripped due to ÀBC` phase fault, Z-II optd.

42 220 KV AMK-BRS FDR. No.3 19-05-2015 14:22 19.05.15 16:53 YES Line tripped due to `BC` phase fault, Z-III optd.

TRIP RESTORED A/R

STATUSREASONS

S.No

.ELEMENT

kanchigupta

Text Box

ANNEX 3

43 220 KV BRS-SATNA 19-05-2015 14:22 19.05.15 15:00 YESLine tripped due to `B` phase fault, Z-I optd. Dist. 27.13

Km.

44 220 KV BRS-SATNA 19-05-2015 16:26 19.05.15 17:35 YESLine tripped due to `CN` phase fault, Z-I optd. H15 Dist.

132 Km.

45 220 KV AMK-SIDHI FDR. B31 22-05-2015 17:24 22.05.15 17:55 YES Line tripped due to À-N` phase fault, Z-II optd.

46 220 KV AMK-ANUPPUR FDR. NO.1 22-05-2015 17:24 22.05.15 17:48 YES Line tripped due to ÀB` phase fault, Z-II optd.

47 220 KV AMK-ANUPPUR FDR. NO.2 22-05-2015 17:24 22.05.15 17:49 YES Line tripped due to ÀB` phase fault, Z-II optd.

48 220 KV AMK-BRS FDR. No.2 22-05-2015 17:24 22.05.15 17:49 YESLine tripped due to ÀB` phase fault, Z-II, 186A, 186B

optd.

49 400KV BRS - KATNI -I FDR. 27-05-2015 13:04 27.05.15 13:44 YES Line tripped on E/F, DT received

50 400KV BRS - KATNI -I FDR. 27-05-2015 18:02 - - YES Line tripped due to overvoltage, DT send

51 400 KV RAITA III FEEDER 27-05-2015 16:18 28.05.15 12:45 feeder faulty

52 220KV SARNI- HANDIA FDR. 28-05-2015 20:14 28.05.15 20:51 NO Line tripped due to overcurrent `B` phase, Z-I optd.


54 400kV VINDHYACHAL-JABALPUR 1 31-05-2015 12:53 31.5.15 12:53 A/R successful on R-E transient fault


56 400 KV KORBA EXTN-1 FEEDER 31-05-2015 16:10 02.06.15 0:02Jumper clearance found to be less on Q transposition

tower- due to heavy storm

57 765kV SATNA-GWALIOR 1 01-06-2015 15:35 1.6.15 16:50 A/T on R-E fault due to live line OPGW works

58 765kV BINA-GWALIOR 3 02-06-2015 17:18 20.6.15 19:23 A/T on Y-B fault due to collapse of towers

59 765kV SATNA-GWALIOR 1 02-06-2015 17:18 2.6.15 18:39 A/T on B-E fault due to live line OPGW works

60 220 KV BRS-AMK FDR. No. II 02-06-2015 13:40 02.06.15 14:01 YesLine Tripped on 'A' phase fault. Z-1 DPR operated.

Distance-32.5 Km.

61 220 KV BRS-SATNA 02-06-2015 19:37 02.06.15 19:57 YESLine Tripped on 'C' phase fault. Z-1 operated.Distance-

143 Km.

62 220 KV TONS-KOTAR FDR 05-06-2015 18:00 05.06.15 18:23 NOLine Tripped due to AN Phase fault, Z-1 operated,

Distt.34.25 Km.

63 400 KV RAITA II FEEDER 05-06-2015 17:27 07.06.15 12:45 Feeder faulty

64 400kV BHACHAU-RANCHHODPURA 207-06-2015 20:26 7.6.15 20:53 A/T on Y-E persisting fault

65 220 KV SARNI HANDIYA FDR. 07-06-2015 12:41 07.06.15 13:16 NOLine Tripped on 'RYB' phase fault. Z-1 operated.

Distance 74.56 Km.

66 400kV JABALPUR-ITARSI 4 08-06-2015 18:17 8.6.15 18:17 A/R Successful on B-E transient fault

67 220 KV AMK-JABALPUR FDR. No. 1 08-06-2015 13:15 08.06.15 23:11 YES Line Tripped due to fault on 'A' Phase, Z-1 operated.

68 220 KV AMK-JABALPUR FDR. No.2 08-06-2015 13:27 08.06.15 13:45 YES Line tripped due to Earth Fault. Z-1 operated.

69 400KV SEONI FEEDER 08-06-2015 17:14 08.06.15 17:59 transient fault. Both ends tripped

70 400kV SHUJALPUR-NAGDA 2 09-06-2015 19:49 9.6.15 19:49 A/R Successful on R-E transient fault

71 765kV VINDHYACHAL(POOLING)-SATNA 110-06-2015 15:12 10.6.15 16:39A/T due to mal operation of OTI in TBEA make reactor

at Satna

72 400kV SEONI-KHANDWA 1 12-06-2015 16:19 12.6.15 16:40 A/T on R-E persisting fault

73 400kV KHANDWA-DHULE 1 12-06-2015 17:44 12.6.15 18:02 A/R successful on R-E transient fault at Khandwa

74 400 KV RAITA III FEEDER 13-06-2015 17:11 14.06.15 12:52 over voltage

75 400KV KORBA EXTN-1 fEEDER 16-06-2015 23:09 17.06.15 1:41 Rain, heavy lightning, fault in Z-1

76 400KV RAIITA KHEDAMARA CKT 1(KORBA WEST)16-06-2015 23:59 16.06.15 1:43from both endstrasient fault.

77 400kV ITARSI-KHANDWA 2 17-06-2015 16:29 18.6.15 16:46A/T on B-E persisting fault due to Insulator string flash

over

78 220 KV AMK-JABALPUR FDR. No.2 17-06-2015 15:14 17.06.15 15:33 YESLine tripped due to fault on 'A-N' phase, Z-1, DPR

operated.

79 220 KV AMK-PANAGAR FDR. 18-06-2015 20:52 18.06.15 21:14 YES Line tripped due to fault on 'A&C' phase, Z-1 operated.

80 220 KV BRS-AMK FDR. No. II 18-06-2015 20:43 18.06.15 21:17 Yes Line Tripped on 'A' phase fault. Z-1 operated.

81 200 KV KORBA EXTN-1 FEEDER 18-06-2015 17:11 18.06.15 19:43 Rain, heavy lightning

82 400 KV BRS- KATNI 1 FDR 19-06-2015 14:04

83 220 KV BRS-SATNA 19-06-2015 15:58 19.06.15 16:20 YESLine Tripped on 'C' phase fault. Z-2 operated. Distance

146 Km.

84 400kV SEONI-KHANDWA 1 21-06-2015 17:32 21.6.15 17:32 A/R successful on R-E transient fault

85 400kV KHANDWA-DHULE 1 21-06-2015 20:51 21.6.15 20:51 A/R successful on Y-E transient fault at Khandwa

86 400KV BRS - KATNI -II FDR. 21-06-2015 8:59 YESLine Tripped on Over Voltage. DT send. * Feeder was

not charged as per system requirement.

87 400 KV SARNI ASTHA FDR. - 1 21-06-2015 21:42 21.06.15 23:29 YESLine tripped on B-Phase fault, Zone-I DPR Optd..

Distance 150 Kms.

88 400 KV SARNI SEONI FDR. 21-06-2015 19:05 21.06.15 19:35 YESLine tripped on Y-Phase to ground fault. Main.I &

Main.II protection optd.

89 400 KV SARNI-SEONI LINE 21-06-2015 19:05 21.06.15 19:35Y phase fault, Main-1 and main-2 protection operated

on y-ph to ground fault at 94.8%.

90 400kV KHANDWA-DHULE 1 22-06-2015 1:10 22.6.15 2:03 A/R successful on R-E transient fault at Khandwa

91 220kV VAPI-KHARADPARA 1 22-06-2015 12:07 22.6.15 16:35A/T on Y-E fault due to Jumper open due to overloading

caused by tripping of ckt#2

92 220kV VAPI-KHARADPARA 2 22-06-2015 12:07 22.06.15 13:11 A/T on B-E fault during heavy wind and severe lighting

93 400 KV SARNI ASTHA FDR. - 1 23-06-2015 15:20 23.06.15 17:20 YES Line tripped on PRV protection of reactor NGT.

94 220 KV SARNI-ITARSI CKT - 2 23-06-2015 0:15 30.06.15 20:28 NOLine Tripped on 'ABC' phase fault. Z-2 operated.

Distance 74.91 Km.

95 220 KV SARNI-ITARSI CKT - 3 23-06-2015 0:16 23.06.15 14:10 NOLine Tripped on 'AB' phase fault. Z-2 operated.

Distance 71.96 Km.

96 220 KV SARNI-ITARSI CKT - 4 23-06-2015 0:16 23.06.15 2:05 NOLine Tripped on 'AB' phase fault. Z-2 operated.

Distance 58.73 Km.

97 220kV VAPI-MAGARWADA 1 24-06-2015 3:21 24.6.15 9:37 A/T on R-E due to snapping of earthwire

98 220kV KAWAS-NAVSARI(GIS) 2 24-06-2015 5:06 24.6.15 6:52 A/T on R-E fault during heavy rain & lightning

99 220kV KAWAS-NAVSARI(GIS) 1 24-06-2015 5:16 24.6.15 13:07 A/T on B-E fault during heavy rain & lightning

100 220kV VAPI-KHADOLI 1 24-06-2015 5:45 24.6.15 7:07 A/T on B-E fault during heavy rain & lightning

101 220kV KAWAS-NAVSARI(GIS) 2 24-06-2015 6:56 24.6.15 13:10 A/T on R-E fault during heavy rain & lightning

102 220kV KAWAS-HALDARWA 1 24-06-2015 19:06 24.6.15 22:33 A/T due to Bus fault at Haldarwa end.

103 220kV KAWAS-HALDARWA 2 24-06-2015 19:06 25.6.15 18:56 A/T due to Bus fault at Haldarwa end.

104 220kV GANDHAR-HALDARWA 1 24-06-2015 19:06 25.6.15 0:56 A/T due to Bus fault at Haldarwa end.

105 220kV GANDHAR-HALDARWA 2 24-06-2015 19:06 25.6.15 16:50 A/T due to Bus fault at Haldarwa end.

106 220kV KAKRAPAR-HALDARWA 1 24-06-2015 19:06 24.6.15 22:08 A/T due to Bus fault at Haldarwa end.

107 220kV KAKRAPAR-HALDARWA 2 24-06-2015 19:06 25.6.15 15:15 A/T due to Bus fault at Haldarwa end.

108 KAPP VAPI-1 24-06-2015 2:52 24.06.15 4:47Y- phase string insulator damaged due to flashover at

2.5Km from VAPI end. Replaced

109 400 KV SARNI I.S.P. FDR. 25-06-2015 3:30 25.06.15 9:50 YES Direct trip received.

110 220 KV AMK-JABALPUR FDR. No. 1 25-06-2015 6:44 25.06.15 6:56 YESLine tripped due to fault on 'A' phase, Z-1, DPR

operated.

111 220 KV SARNI-ITARSI CKT - 4 25-06-2015 19:34 25.06.15 20:17 NOBroken conductor protection optd.(current R phase -

55.65 Amp, Y phase-35.39 A, B phase-88.82 A)

112 400KV SARNI ISP LINE 25-06-2015 3:30 25.06.15 09:50 HrsOver voltage. First stage operated

113 220kV NAVSARI(GIS)-NAVSARI 1 26-06-2015 9:57 26.6.15 16:50 A/T on R-Y fault due to opening of Y phase jumper

114 765kV SATNA-BINA 1 27-06-2015 16:42 27.6.15 17:26A/T due to accidental opening of CT wire of REF

Protection

115 220 KV AMK-JABALPUR FDR. No. 1 28-06-2015 17:48 28.06.15 20:56 YESLine tripped due to fault on 'AB' phase, Z-1, DPR

operated.

116 765kV BINA-GWALIOR 3 01-07-2015 16:22 1.7.15 16:54 A/T on Y-E persisting fault

117 400kV INDORE(MP)-INDORE(POOLING) 101-07-2015 19:28 1.7.15 19:55A/T only from Indore(MPPTCL) on Pole discrepancy

relay operation due to DC leakages

118 400kV INDORE(MP)-INDORE(POOLING) 103-07-2015 14:54 4.7.15 19:58A/T only from Indore(MPPTCL) on Pole discrepancy

relay operation due to DC leakages

119 400kV KHANDWA-DHULE 2 04-07-2015 20:13 5.7.15 15:29 A/T on R-Y due to opening of jumper

120 220 KV AMK- ANUPPUR FDR. .II 04-07-2015 14:52 04.07.15 15:14 YES Line tripped due to `B` phase fault, Z-I optd.

121 400 KV BRS- KATNI II FDR 05-07-2015 17:51 05.07.15 21:28 Hand tripped

122 400kV NAVSARI(GIS)-MAGARWADA(GIS) 108-07-2015 0:40 8.7.15 21:39A/T on R-Y fault during heavy lightening and thunder

storm.

123 765KV VADODARA(GIS)-INDORE(POOLING) 108-07-2015 2:17 8.7.15 16:16A/T on R-B fault due to tracking on insulator caused by

heavy pollution

124 400kV INDORE(MP)-ASOJ 1 08-07-2015 3:22 8.7.15 11:51 A/T on Y-E fault during Torrential Rain & flood

125 220 KV AMK- JABALPUR FDR. I 08-07-2015 3:56 08.07.15 4:07 YES Line tripped due to ÀN` phase fault, Z-1 optd.

126 400 KV BRS- KATNI II FDR 09-07-2015 5:03 13.07.15 22:30

127 400KV BRS -KATNI - FDR II. 09-07-2015 5:03 13.07.15 22:30 YES DT received

128 400kV ANUPPUR-JABALPUR(POOLING) 110-07-2015 4:18 10.07.15 7:49A/T due to operation of Over Voltage protection at

Anuppur end.

129 220kV VAPI-KHADOLI 1 10-07-2015 22:00 11.7.15 10:52 A/T on R-E fault due to insulator flash over

130 400 KV SARNI- ASTHA FDR -I 10-07-2015 12:54 10.07.15 15:01 YES Line tripped on PRV protection of reactor.

131 220 KV BRS -AMK FDR. III 10-07-2015 13:32 10.07.15 13:50 YESLine tripped due to À` phase fault, Z-I optd. Distance

45.50 Km.

132 220 KV BRS - PANAGAR FDR. 13-07-2015 11:45 13.07.15 12:37 YES Line tripped due to À` phase fault, Z-2 optd.

133 220 KV BRS - PANAGAR FDR. 13-07-2015 12:40 14.07.15 17:58 YES Line tripped due to À` phase fault, Z-2 optd.

134 200 KV TAPS-BORIVILI 13-07-2015 12:34 13.07.15 13:20

LOCAL END : Started phase c, Trip phase A,B,C, Z-1 fault,

Distance : 6.36km, Ia-991A, Ic-11.97kA, carrier sent.

REMOTE END: ABC, PHASE trip, back up over current

protection operated, carrier received/sent, Ia-995A,Ib-

340A,Ic-2.56kA

135 200 KV TAPS-BORIVILI 13-07-2015 11:37 13.07.15 12:08

LOCAL END: started phase C, Trip phase ABC, Z-1 Fault,

Distance: 6.49 km,Ia-998.5A, Ib-377.4A,Ic-11.65kA,

carrier sent. REMOTE END: ABC,Trip, b/u, o/c protection

operated, carrier received/sent. Ia-993A,Ib-337A,Ic-

2.386kA

136 765KV VADODARA(GIS)-INDORE(POOLING) 114-07-2015 4:03 14.7.15 19:58A/T on R-Y-B ph fault due to electrical tracking of

insulator strings caused by heavy pollution

137 400kV INDORE(MP)-ASOJ 2 14-07-2015 5:38 14.7.15 5:38 A/R successful on B-E transient fault

138 400 KV BRS- KATNI II FDR 14-07-2015 18:20 14.07.15 20:15 Hand tripped, due to syatem requirements

139 765KV VADODARA(GIS)-INDORE(POOLING) 115-07-2015 5:49 15.7.15 6:29A/T on R-E fault due to tracking on insulators due to

heavy polution.

140 400kV INDORE(MP)-ASOJ 2 16-07-2015 20:18 17.7.15 17:43 A/T on Y-E persisting fault caused by Insulator flashover

141 220KV TONS- KOTAR FDR 16-07-2015 13:11 16.07.15 13:35 NO

Line tripped due to `CN` phase fault, Distance trip Z-1

optd. Distance

4.343 kms.

142 220 KV AMK - BRS FDR..III 17-07-2015 22:47 17.07.15 23:14 YES Line tripped due to `A` phase fault, Z-I optd.

143 400kV SHUJALPUR-NAGDA 1 18-07-2015 2:25 20.7.15 13:58 A/T on B-E persisting fault due to insulator flashover

144 765kV BINA-INDORE(POOLING) 1 18-07-2015 7:00 18.7.15 17:02 A/T on R-B fault during heavy rain & lightening

145 400kV NAGDA-DEHGAM 1 18-07-2015 7:31 21.7.15 18:49 A/T on R-E persisting fault caused by Insulator flashover

146 765KV VADODARA(GIS)-INDORE(POOLING) 118-07-2015 12:28 19.7.15 12:22A/T on B-E persisting fault due to electrical tracking of

insulator

147 400kV NAGDA-DEHGAM 2 18-07-2015 15:14 23.7.15 20:21A/T on B-E persisting fault due to tower cross arm bent

during localized wind and torrential rain

148 400kV INDORE(MP)-ASOJ 2 18-07-2015 20:31 19.07.15 19:24 A/T on Y-E persisting fault due to flashover of insulator

149 400 KV SARNI I.S.P. FDR. 18-07-2015 2:25 18.07.15 13:25 YESLine tripped due to B-phase fault. Main-I & Main-II

protection, Z-1 optd.

150 400kV INDORE(MP)-ASOJ 1 19-07-2015 2:37 19.7.15 4:04 A/T on R-Y Fault during rain & lightening

151 400 KV BRS- KATNI II FDR 19-07-2015 7:48 20.07.15 21:20

152 400KV BRS -KATNI -FDR II. 19-07-2015 7:48 20.07.15 21:20 YES DT received

153 765KV VADODARA(GIS)-INDORE(POOLING) 120-07-2015 20:19 21.7.15 12:59 A/T on R-E persisting fault due to tracking on insulator

154 400kV INDORE(MP)-ASOJ 1 20-07-2015 21:24 20.7.15 22:16A/T on R-E persisting fault due to heavy rain &

lightening

155 400kV INDORE(MP)-ASOJ 2 21-07-2015 0:57 21.7.15 16:12A/T on Y-E persisting fault caused by flashover of

insulator string

156 400kV INDORE(MP)-ASOJ 1 21-07-2015 2:41 21.7.15 2:55A/T on R-E persisting fault during heavy rain, thunder

storm

157 400 KV BRS- KATNI II FDR 21-07-2015 22:44 26.07.15 22:44 hand tripped

158 400 KV SARNI ASTHA FDR -I 21-07-2015 5:19 21.07.15 18:02 YESLine tripped on Distance protection, Zone-1 optd.

Distance 77.37 Kms.

159 400KV VADODARA(GIS)-PIRANA 2 22-07-2015 2:11 22.7.15 12:55A/T on Y-E persisting fault during heavy rains and

thunder storm

160 400KV VADODARA(GIS)-PIRANA 1 22-07-2015 5:25 22.7.15 12:34A/T on Y-E persisting fault during heavy rains and

thunder storm

161 220kV KAWAS-NAVSARI(GIS) 1 22-07-2015 7:28 22.7.15 8:27 A/T on B-E during heavy lightening and thunder storm

162 400kV VINDHYACHAL-JABALPUR 1 22-07-2015 19:53 22.7.15 20:15A/R successful on Y-E transient fault at Jabalpur only

and failed at Vindhyachal end

163 400 KV SARNI I.S.P. FDR. 22-07-2015 3:53 22.07.15 6:20 YES DT received

164 220KV TONS- REWA FDR No. I 23-07-2015 14:35 23.07.15 15:06 NO

Line tripped due to `AN` phase fault, Distance trip Z-1

optd. Distance

38.78 kms.

165 220 KV BRS -SATNA FDR. 24-07-2015 12:17 24.07.15 12:32 YESLine tripped due to `C` phase fault, Z-3 optd. Distance

117 km.

166 400kV NAGDA-DEHGAM 1 25-07-2015 3:55 25.7.15 15:10 A/T on B-E persisting fault caused by insulator flashover

167 400kV INDORE(MP)-ASOJ 2 25-07-2015 14:37 25.07.15 15:12 A/T due to failure of CVT at Indore (MP) end

168 400 KV SARNI ASTHA FDR -I 25-07-2015 1:40 25.07.15 5:59 YES Line tripped on Over voltage stage-I protection.

169 250 MW STPS UNIT # 11, SARNI 25-07-2015 1:10 NA

Unit tripped on class-'A' protection due to failure of 'B

phase' HV bushing of 315 MVA, 16.5/400 KV Generator

Transformer.

170 220kV KAWAS-NAVSARI(GIS) 2 28-07-2015 9:55 28.7.15 15:08A/T on R-E fault during heavy lightening and thunder

storm

171 400kV MUNDRA-LIMBDI 1 28-07-2015 11:21 28.7.15 11:55 A/T on R-E persisting fault.

172 400kV VINDHYACHAL-JABALPUR 4 01-08-2015 22:47 1.8.15 22:47 A/R on B-E transient fault

173 ICT2 JABALPUR(POOLING) 765/400kV03-08-2015 20:13 3.8.15 23:37 A/T due to moisture entry in PRD OLTC

174 220 KV AMK-SIDHI FDR 04-08-201513.22 Hrs.04.08.201513.37 Hrs.Provided but not in service due to outage of protection coupler at that end.Line tripped due to `C-N` phase fault, Z-1 optd.

175 400 KV SARNI I.S.P. FDR 04-08-201501.59 Hrs.05.08.201501.29 Hrs. YesLine tripped due to `R` phase fault, Main-I & Main-II

protection optd.

176 220 KV TONS-REWA FDR I & II 05-08-201507.50 Hrs.05.08.201508.45 & 08.55 Hrs.respectively.NoLine tripped due to `B` phase fault, Z-1 .due to Pole

descrepancy occurred at the time of handtripping of unit

#1.

177 220 KV TONS-KOTAR FDR 05-08-201507.50 Hrs.05.08.201508.40 Hrs. NoLine tripped due to `B` phase fault, Z-1 .due to Pole


#1.

178 220 KV TONS-SATNA FDR 05-08-201507.50 Hrs.05.08.201508.25 Hrs. NoLine tripped due to `B` phase fault, Z-1 .due to Pole


#1.

179 105 MW GENERATOR UNIT # 1 & II OF TONS HPS, SIRMOUR05-08-201507.50 Hrs.06.08.201500.35 hrs ( Gen. # I)NA Units tripped due to Pole descrepancy occurred at the

time of handtripping of unit #1.

180 220 KV BRS-SATNA FDR 08-08-201511.55 Hrs.08.08.201512.06 Hrs. Yes Line tripped due to `C` phase fault, Z-1 optd.

181 220kV VAPI-KHADOLI 1 09-08-2015 15:34 9.8.15 16:46 A/T on B-E fault due to insulator flashover

182 220 KV BRS-SATNA FDR 09-08-201512.10 Hrs.09.08.201512.19 Hrs. Yes Line tripped due to `C` phase fault, Z-1 optd.

183 220 KV TONS-REWA FDR II 09-08-201520.11 Hrs.09.08.201520.38 Hrs. No Line tripped due to `C` phase fault, Z-II optd.

184 765kV VINDHYACHAL(POOLING)-SATNA 110-08-2015 20:03 11.8.15 1:25 A/T on R-B fault during heavy rain and thunder storm

185 220 KV BRS-AMK FDR II 10-08-2015 18.18 Hrs10.08.201519.00 Hrs Yes Line tripped due to À` phase fault, Z-1 optd.

186 220 KV BRS-SATNA FDR 10-08-2015 18.18 Hrs10.08.201518.40 Hrs Yes Line tripped due to À` phase fault, Z-1 optd.

187 220 KV BRS-SATNA FDR 10-08-2015 22.55 Hrs11.08.201502.50 Hrs Yes Line tripped due to `C` phase fault, Z-2 optd.

188 220 KV AMK-JABALPUR FDR II 10-08-201517.34 Hrs.10.08.201517.49 Hrs. Yes Line tripped due to À` phase fault, Z-1 optd.

189 220 KV AMK-BIRSINGHPUR FDR II 10-08-201517.51 Hrs.10.08.201518.06 Hrs. Yes Line tripped due to À` phase fault, Z-1 optd.

190 220 KV AMK-PANAGAR FDR 10-08-201517.53 Hrs.10.08.201518.08 Hrs. Yes Line tripped due to `C` phase fault, Z-1 optd.

191 220 KV AMK-BIRSINGHPUR FDR III 10-08-201518.24 Hrs.10.08.201518.54 Hrs. Yes Line tripped due to À` phase fault, Z-2 optd.

192 400kV INDORE(MP)-ASOJ 2 11-08-2015 3:00 11.8.15 15:45 A/T on R-E fault due to insulator flashover

193 220 KV AMK-BIRSINGHPUR FDR III 11-08-201521.53 Hrs.12.08.201512.12 Hrs. Yes Line tripped due to À` phase fault, Z-1 optd.

194 220 KV AMK-JABALPUR FDR II 12-08-201513.26 Hrs.12.08.201513.35 Hrs. Yes Line tripped due to `C` phase fault, Z-1 optd.

195 220 KV AMK-JABALPUR FDR I 12-08-201514.33 Hrs.12.08.201514.57 Hrs. Yes Line tripped due to `C` phase fault, Z-1 optd.

196 200 KV TAPS VAPI 13-08-2015 14:30 13.08.15 17:29

LOCAL END: started phase b&c, z-2 fault, distance:

73.12 km, Ib-2.682kA, Ic-2.646kA. REMOTE END: Z-1

fault, Distance: 3.24 km, Ib-7.59kA, Ic-7.59kA

197 220 KV BRS-AMK FDR II 14-08-2015 05.45 Hrs14.08.201506.15 Hrs Yes Line tripped due to `B` phase fault, Z-1 optd.

198 765kV GWALIOR-JAIPUR 2 15-08-2015 13:37 15.08.2015 19:27 A/T on Receipt of DT from Jaipur end

199 400kV VINDHYACHAL-KORBA 2 15-08-2015 11:14 16.8.15 5:27 A/T on B-E persisting fault

200 400KV BRS-KATNI FDR II 15-08-201513.02 Hrs.19.08.201516.29 Hrs. Yes DT Received

201 765kV GWALIOR-JAIPUR 2 16-08-2015 17:10 16.8.15 19:22 A/T on Receipt of DT from Jaipur end

202 220 KV BRS-SATNA FDR 16-08-2015 22.27 Hrs16.08.201522.41 Hrs Yes Line tripped due to `C` phase fault, Z-1 optd.

203 220 KV AMK-SIDHI FDR 16-08-201522.27 Hrs.17.08.201513.11 Hrs.Provided but not in service due to outage of protection coupler at that end.Line tripped due to À` phase fault, Z-1 optd.

204 220 KV AMK-BIRSINGHPUR FDR II 17-08-201516.15 Hrs.17.08.201518.05 Hrs. Yes Line tripped due to `BC` phase fault, Zone-I optd.

205 220 KV TONS-SATNA FDR 20-08-201519.04 Hrs.20.08.201519.40 Hrs. No Line tripped due to À` phase fault.DPR optd.

206 400KV BRS-KATNI FDR I 23-08-201514.09 Hrs.

As per

system

requirem

ent, Line

was not

charged

till date.

Yes DT Received

207 220 KV BRS-SATNA FDR 26-08-201513.30 Hrs.26.08.201513.41 Hrs. Yes Line tripped due to `BC` phase fault, Z-1 optd.

208 220 KV AMK-PANAGAR FDR 27-08-201521.23 Hrs.

continue

in

shutdown

Yes Line tripped due to `C-N` phase fault, Z-1 optd.

209 400 KV SARNI I.S.P. FDR 28-08-201503.38 Hrs.28.08.201505.50 Hrs. YesLine tripped due to over voltage, 1st stage protection

optd.

210 ICT1 VINDHYACHAL(POOLING) 765/400kV30-08-2015 1:18 30.8.15 17:54 ICT Tripped due to DC earth leakage

211 220 KV TAPS -VAPI 01-09-2015 11:58 01.09.15 12:36

LOCAL END: started C phase, Z-1 fault, Distance- 53.59

km, Ic-2.630 kA, Vcn-112.1 kV REMOTE END- Z-1 fault,

distance: 50.3 KM, Ic-2.218kA

212 200 KV TAPS VAPI 01-09-2015 11:58 01.09.15 12:36

LOCAL END: Started phase c, Z-1 fault, Distance-53.59

km, Ic-2.63kA, Vcn-112KV. REMOTE END: Z-1 fault,

Distance 50.3 km, Ic-2.218kA

213 765KV VADODARA(GIS)-INDORE(POOLING) 103-09-2015 11:05 3.9.15 11:44 A/T due to failure of Main CB

214 400KV BRS - KATNI FDR-II 03-09-2015 14:52 04.09.15 13:04 Yes DT received

215 220 KV BRS-PANAGAR FDR 03-09-2015 13:25 03.09.15 13:51 -- Line Tripped due to 'A' phase fault, Z-I optd.

216 220 KV BRS-SATNA 03-09-2015 9:50 03.09.15 10:43 -- Line Tripped due to BC phase fault, Z-I optd.

217 220 KV AMK-SIDHI FDR 03-09-2015 22:12 03.09.15 22:31Provided but not in service due to outage of protection coupler at that end.Line Tripped due to 'A' phase fault, Z-I optd.

218 400kV KHANDWA-DHULE 2 04-09-2015 5:13 4.9.15 5:13 A/R successful on B-E transient fault

219 220 KV BRS-SATNA 04-09-2015 11:50 04.09.15 19:48 --Line tripped due to C phase fault, Broken conductor

protection operated.

220 220 KV BRS-PALI I/C-IV 04-09-2015 13:58 04.09.15 16:17 -- Line Tripped due to 'C' phase fault, Z-1 optd.

221 220 KV AMK-BRS FDR-II 04-09-2015 13:59 04.09.15 14:20 Yes Line Tripped due to 'C' phase fault, Z-2 optd.


223 220 KV BRS-AMK FDR-II 11-09-2015 11:30 11.09.15 11:58 -- Line Tripped due to 'A' phase fault, Z-I optd.


225 220 KV AMK-JBP FDR-I 11-09-2015 4:42 11.09.15 4:55 Yes Line Tripped due to 'C' phase fault, Z-I optd.

226 220 KV AMK-JBP FDR-II 11-09-2015 5:33 11.09.15 5:46 Yes Line Tripped due to 'A' phase fault, Z-I optd.

227 220 KV AMK-JBP FDR-I 11-09-2015 11:20 11.09.15 11:45 Yes Line Tripped due to 'A' phase fault, Z-I optd.

228 400kV VINDHYACHAL-SATNA 1 12-09-2015 12:44 12.9.15 13:36A/R successful at Satna end only on transient B-E fault

but AR failed at Vchal NTPC end

229 400kV GANDHAR-NAVSARI(GIS) 2 12-09-2015 19:04 12.9.15 20:15 A/T on B-E persisting fault

230 KAKRAPAR VAPI -1 12-09-2015 13:11 12.09.15 18:11 fault appeared at 433.6 m from vapi

231 220 KV BRS-AMK FDR-II 12-09-2015 10:50 12.09.15 11:20 -- Line Tripped due to DPR, Z1 optd.

232 220 KV AMK-JBP FDR-I 12-09-2015 10:52 12.09.15 11:06 Yes Line Tripped due to 'A' phase fault, Z-I optd.

233 400kV MUNDRA-JETPUR 2 13-09-2015 20:54 13.9.15 20:54 A/R Successful on R-E transient fault


235 400 KV SARNI-ISP FDR 13-09-2015 15:55 13.09.15 16:25 YesLine Tripped due to 'B' phase to ground fault, Main I &

Main II protection optd.

236 220 KV AMK-SIDHI FDR 13-09-2015 12:00 13.09.15 12:27Provided but not in service due to outage of protection coupler at that end.Line Tripped due to BCNphase fault, Z-I optd.

237 400 KV SARNI I.S.P Line 13-09-2015 15:55 13.09.15 16:25B-N fault. 26.3% from sarni end. Both ends main-1 and

main 2 protection operated

238 220 KV BRS-PANAGAR FDR 14-09-2015 14:52 14.09.15 15:18 -- Line Tripped due to 'C' phase fault, Z-I optd.

239 220 KV BRS-SATNA 14-09-2015 17:45 16.09.15 18:17 -- Line Tripped due to 'C-N' phase fault, Z-I optd.

240 220 KV AMK-JBP FDR-I 14-09-2015 15:00 14.09.15 15:11 Yes Line Tripped due to CNphase fault, Z-I optd.

241 220 KV AMK-SIDHI FDR 14-09-2015 16:16 15.09.15 15:14 Yes Line Tripped due to 'B' phase fault, Z-I optd.

242 400kV ITARSI-INDORE(MP) 2 15-09-2015 12:50 15.9.15 13:48 A/T due to Bucholz protection operation at Itarsi end

243 765kV SATNA-BINA 2 15-09-2015 17:37 15.09.15 17:37 A/R on B-E transient fault

244 400kV KHANDWA-DHULE 2 16-09-2015 19:45 16.9.15 20:00 A/T on B-E persisting fault

245 400kV ITARSI-INDORE(MP) 2 17-09-2015 15:48 17.9.15 23:33 A/T on R-E persisting fault

246 400 KV SINGAJI-PITHAMPUR FDR-II 17-09-2015 15:45 17.09.15 17:25 Yes Line Tripped due to 'Y-N' phase fault, Z-I optd.

247 220 KV BRS-SATNA 17-09-2015 6:47 17.09.15 7:08 -- Line Tripped due to 'C' phase fault, Z-2 optd.

248 765kV GWALIOR-JAIPUR 2 18-09-2015 13:38 18.9.15 14:18A/R successful on Y-E transient fault, but AR failed at

Jaipur end

249 ICT3 BOISAR 400/220kV 18-09-2015 15:27 18.9.15 16:51 A/T due mositure entry in Oil surge relay

250 220kV VAPI-MAGARWADA 1 19-09-2015 10:10 19.9.15 13:22 A/T on R-E fault due to earthwire snapping

251 400kV VINDHYACHAL-JABALPUR 1 19-09-2015 19:13 19.9.15 19:13 A/R on R-E transient fault

252 220 KV AMK-JBP FDR-II 19-09-2015 11:25 19.09.15 11:30 Yes Line Tripped due to 'C' phase fault, Z-I optd.

253 220 KV AMK-PANAGAR FDR 19-09-2015 12:57 19.09.15 13:13 Yes Line Tripped due to 'A' phase fault, Z-I optd.

254 220 KV AMK-PANAGAR FDR 19-09-2015 17:27 19.09.15 17:41 Yes Line Tripped due to 'C' phase fault, Z-I optd.



257 220 KV TAPS VAPI 21-09-2015 6:11 21.09.15 15:45

LOCAL END: started phase -b&c, Z-1 fault, distance:

3.090 km. Ic-kA, Vcn-127.6 kV , carrier sent . REMOTE

ECND: Z-2 fault, distance : 72.43 km, Ib- 2.947 kA, Ic-

2.718 kA.

258 400kV VAPI-BOISAR 22-09-2015 10:33 22.9.15 10:51 A/T on R-E persisting fault

259 400 KV SARNI-KORADI FDR 22-09-2015 12:03 22.09.15 15:13 YesLine Tripped due to 'C.B' pole discrepancy protection

optd.

260 400 KV SARNI KORADI LINE 22-09-2015 12:03 22.09.15 15:13

C.B pole discrepancy, thereafter line hand tripped from

koradi end. Panel wire was found faulty. Wire replaced,

breaker closed, trip trail taken.

261 220kV NAVSARI(GIS)-NAVSARI 1 23-09-2015 20:23 24.9.15 12:51 A/T on R-E due to opening of Jumper

262 400 KV SARNI-ASTHA FDR 23-09-2015 6:37 23.09.15 9:07 Yes Line Tripped due to 'R' phase fault, Z-3 optd.

263 KAPP VAPI-1 24-09-2015 9:43 24.09.15 10:20Fault appeared at 57.6 Km from Vapi end.(fdr length-

110Km)

264 KAPP VAPI-1 24-09-2015

265 765kV VINDHYACHAL(POOLING)-SATNA 227-09-2015 16:06 27.9.15 19:09 A/T on Y-E persisting fault

266 220kV VAPI-KHARADPARA 2 29-09-2015 18:46 29.9.15 19:22 A/T on R-E fault

267 220kV VAPI-KHARADPARA 1 29-09-2015 19:17 30.9.15 00:22A/T due to R phase Jumper opening caused by

overloading of this line after tripping of Line#2

268 220 KV BRS-PANAGAR FDR 29-09-2015 14:08 29.09.15 14:29 --Line Tripped due to 'A&B' phase fault,67NXEarth fault

relay optd.

269 400 KV SARNI-ISP FDR 30-09-2015 4:55 30.09.15 6:21 YesLine tripped due to over voltage 1st stage protection

optd.

270 400 KV SARNI-ISP FDR 30-09-2015 14:34 30.09.15 14:50 YesLine Tripped due to 'Y' phase fault, Main I & Main II

protection optd.

271 220 KV AMK-JBP FDR-II 30-09-2015 10:39 30.09.15 10:54 Yes Line Tripped due to 'C' phase fault, Z-I optd.

272 400 KV SARNI ISP LINE 30-09-2015 4:55 30.09.15 6:21Tripped due to overvoltage. 1st stage protection

operated

273 400 KV SARNI ISP LINE 30-09-2015 14:34 30.09.15 14:50Y phase fault, both end main1- main 2 protection

operated. Distance : 38.4% from sarni end

274 220 KV AMK-JBP FDR-II 01-10-2015 12:15 01.10.15 12:30 Yes Line Tripped due to 'C' phase fault,Z-I optd.

275 220 KV AMK-JBP FDR-II 01-10-2015 12:15 01.10.15 12:30 Yes Line Tripped due to 'C' phase fault,Z-I optd.

276 220 KV BRS-AMK FDR-II 03-10-2015 16:05 03.10.15 17:12 -- Line Tripped due to 'BN' Phase fault, Z-I optd.

277 220 KV BRS-AMK FDR-II 03-10-2015 16:05 03.10.15 17:12 -- Line Tripped due to 'BN' Phase fault, Z-I optd.

278 400/220 KV I.C.T 04-10-2015 6:30 04.10.15 8:55

unit no 7 tripped on GT over all differential protection

R&B phase , GT b/u e/f protection and simultaneously

400 KV/220 KV I.C.T. Both side C.B tripped on 400 KV ,

220 KV side B-phase and backup instantaneous o/c

protection operated. After clearance from L/D , PH-1

&PH-2 and ICT charged from 220KV side

279 220 KV AMK-BRS FDR-III 04-10-2015 13:10 04.10.15 13:51 Yes Line Tripped due to 'C-N' Phase fault, Z-1, Z-2 optd.

280 220 KV AMK-BRS FDR-III 04-10-2015 13:10 04.10.15 13:51 Yes Line Tripped due to 'C-N' Phase fault, Z-1, Z-2 optd.

281 220 KV Tons-Satna FDR 06-10-2015 11:03FDR is not charged till now. No Line tripped due to 'BC-N' Phase fault, Z-2 optd.

282 220 KV Tons-Satna FDR 06-10-2015 11:03FDR is not charged till now. No Line tripped due to 'BC-N' Phase fault, Z-2 optd.

283 400 KV BRS- KATNI 1 FDR 08-10-2015 14:16 09.10.15 14:31

284 400 KV BRS- KATNI 1 FDR 09-10-2015 14:37 10.10.15 13:30

285 220 KV AMK-SIDHI FDR 16-10-2015 14:22 16.10.15 14:44Provided but not in service due to outage of protection coupled at that end.Line Tripped due to 'C' Phase fault, Z-1, Z-2 optd.

286 220 KV AMK-SIDHI FDR 16-10-2015 14:22 16.10.15 14:44Provided but not in service due to outage of protection coupled at that end.Line Tripped due to 'C' Phase fault, Z-1, Z-2 optd.

287 400 KV BRS-KATNI 1 FDR 17-10-2015 11:00 21.10.15 10:30

288 200 KV TAPS VAPI 17-10-2015 13:38 17.10.15 14:22

LOCAL END: A,B,C pick up, Z-1 fault, cphase started, Ic-

2.99 kA ,Z-1 trip, Distance-47 Km , Carrier sent and

received. REMOTE END : Z-1 fault, C- phase started, Z-1

trip, Distance- 35.8 Km, Carrier sent and received.

289 220 KV TAPS BHILAD 18-10-2015 13:12 18.10.15 14:09

LOCAL END: C phase pick up, E/F pick up, O/C & E/F trip,

General trip, Z-1 trip, 43.1 Km, carrier received and

sent. REMOTE END : Distance protection operatted, Z-1

fault, Z-1 trip, C phase started, Distance 47.13 km, Ic-

229.2 A

290 220 KV Sarni-S/s Interconnector-II 20-10-2015 12:34 20.10.15 13:21 No Line tripped due to Y-B phase fault, overcurrent.

291 220 KV BRS-PANAGAR FDR 20-10-2015 10:45 20.10.15 11:07 -- Line Tripped due to 'A' phase fault,Earth fault .

292 220 KV Sarni-S/s Interconnector-II 20-10-2015 12:34 20.10.15 13:21 No Line tripped due to Y-B phase fault, overcurrent.

293 220 KV BRS-PANAGAR FDR 20-10-2015 10:45 20.10.15 11:07 -- Line Tripped due to 'A' phase fault,Earth fault .

294 400 KV BRS- KATNI 1 FDR 28-10-2015 18:17

295 400 KV SINGAJI- JULWANIA FDR 28-10-2015 18:39 28.10.15 19:41Fault in Y phase, distance 50.43 Km from Singaji end.

Kept out due to over voltage

296 400 KV SINGAJI-II Julwania FDR 28-10-2015 18:39

The

feeder

was not

charged

as per

instructio

n of SLDC.

Yes

Line tripped due to 'Y-N' phase fault, Z-1 optd. Line was

charged on 28.10.15 at 19:14 hrs but not hold due to

overvoltage.

297 220 KV BRS-PANAGAR FDR 28-10-2015 13:55 28.10.15 14:15 -- Line Tripped due to 'C' phase fault,Z-2 optd.

298 400 KV SINGAJI-II Julwania FDR 28-10-2015 18:39

The

feeder

was not

charged

as per

instructio

n of SLDC.

Yes

Line tripped due to 'Y-N' phase fault, Z-1 optd. Line was

charged on 28.10.15 at 19:14 hrs but not hold due to

overvoltage.

299 220 KV BRS-PANAGAR FDR 28-10-2015 13:55 28.10.15 14:15 -- Line Tripped due to 'C' phase fault,Z-2 optd.

300 220 KV AMK-PANAGAR FDR 31-10-2015 15:27 31.10.15 15:47 Yes Line tripped due to 'A-N' Phase fault, DPR Optd.

301 220 KV AMK-PANAGAR FDR 31-10-2015 15:27 31.10.15 15:47 Yes Line tripped due to 'A-N' Phase fault, DPR Optd.

302 220 KV BRS-PANAGAR FDR 03-11-2015 10:40 03.11.15 11:08 Line tripped due to 'A' phase fault,Z-2 optd.

303 220 KV BRS-REWA FDR 12-11-2015 19:01 12.11.15 19:23Line tripped due to 'C' phase fault,Z-1 optd. Distance

82.5 Km

304 220 KV BRS-REWA FDR 12-11-2015 20:00 12.11.15 20:12Line tripped due to 'C' phase fault,Z-1 optd. Distance

80.5 Km

305 220 KV AMK-BRS FDR-II 21-11-2015 15:02 21.11.15 15:20 Yes Line tripped due to 'Breaker Tripped' , 86 L/O optd.

306 220 KV TAPS- VAPI 25-11-2015 15:59 25.11.15 16:19

LOCAL END : A,B,C tripped, Z-1 fault, C phase started, Ic-

4.067 kA, Z-1 Trip,Distance 19 Km, Carrier sent REMOTE

END: Z-1 fault, Phase C tripped, Ic- 2.046 kA, Z-1 Trip,

Distance- 73.31 Km

307 220 KV AMK-PANAGAR FDR 27-11-2015 10:08 27.11.15 10:22 Yes Line tripped due to 'A' phase fault,Z-1, optd.

308 220 KV AMK-SINDHI FDR 27-11-2015 13:50 27.11.15 14:05Provided but not in service due to outage of protection

coupler at that end

MINUTES

FOR SPECIAL MEETING HELD ON 16.02.2016

Aspecialmeetingwasheldon16thofFebruary2016inaccordancewiththediscussionheldinthe126th

PCM,thereaftertheitemsweretakenupfordiscussionpertainingtoitemnumber5.1,5.2andItemno6

ofthemainPCMAgenda.

SE(Protection&Studies)welcomedalltheparticiapantsofthemeetingandbriefedthemembersabout

theagendaforthemeeting.

1) ITEM NO 5.1 :StatusofCompliancesofobservationsasperHon’bleCERC’sorder:

SE(P&C)WRPC, clarified in themeeting that everyquarter, datahas tobe filed toCERC regarding the

protection audit. The last submitted data was for quarter ending 30.09.2015.The constituents were

requestedtobringhardcopiesofthedataforQuarter3ending31stDecember2015,forthismeeting.

HardcopyofthedataforQuarterending31stDecember2015wasreceivedfromMPonly.Hardcopies

havenotbeenreceivedfromMaharashtaandChattisgarhalthoughsoftcopieshavebeenreceivedfrom

themandhavebeencompiledbyWRPC.Datashouldbefurnishedforthisexerciseregularly.

2) ITEM NO 5.2 : Grid Disturbance on 30.07.2012 & 31.07.2012 (Petition No. 167/Suo-

Motu/2012)

In compliance with Hon’ble CERC’s vide order dated 22.02.2014 in the matter of grid disturbance

occurred on 30.07.2012 & 31.07.2012 in petition No. 167/Suo-Motu/2012, maintenance of data

regardingtherelaysettingsdataofalltheISTSlinesandlinesemanatingfrominterfaceS/SsofUtilitiesto

ISTS(400kV&aboveand220kVinterfacinglines)ismandatedandthesamewasdiscussed.Allutilities

wererequestedtosubmit latestrelaysettingdatatoWRPC/WRLDC. Constituentswerealsorequested

to bring updated hard and soft copies as on December 2015.The data had been received from MP,

GETCOandMaharashtra.PGCIL,CSPTCL,ISGS,Goa,andDD&DNHwererequestedtofurnishtheabove

dataimmediately.

In this regard it was decided in the meeting that ,the existing settings pertaining to only distance

protection of networkwill be updated by all CTU/STU. For newunits commissioned, the samewill be

checkedbyCTU/STU.NetworkprotectiondatashallbemaintainedbyCTU?STUandacopyofthesame

shall be furnished toWRPC/WRLDC. For gencos, protectiondatapertaining todistanceprotection and

their settings shall be maintained by Gencos. The reaches of the distance relays shall be checked by

kanchigupta

Text Box

ANNEX 5

CTU/STUsothattheyareinorder.Tillsuchtimeacommondatabaseisformed,theexistingrelaysettings

maybesenttoWRPCandWRLDCintheexistingformatformaintenance.

3) ITEMNO.6:Statusof implementationofrecommendationsofReportonGriddisturbanceon

30thand31stJuly2012inWR.

In compliancewith the recommendationsof theenquirycommitteeof thegriddisturbanceon

30th&31stJuly,2012inNEWgridallutilities/SLDCs/RLDCwererequiredtosubmitupdatedstatus

onimplementationofrecommendationsmadebythecommitteetoRPC.

ItwasdecidedthatthestatusshallbesubmittedyearwiseseparatelyforFY2012-13,2013-14

and2014-15andthedatamaybefurnishedonquarterlybasisforApril–2014onwards.

Itwasindicatedthattherewerediscrepanciesormismatchinrespecttoprotectionauditdatafurnished

by utilities for submission to CEA in format and to CERC in format. Itwas opined that to have a clear

pictureof implemented statusonabove recommendations in respectofprotectionaudit, utilitiesmay

submittheconsolidatedanddetailedstatusofall132kV,220kV,400kVand765kVS/s.Itwasalsofelt

thatSLDCsandWRLDCwouldcoordinatetogetthedetails.

Further,itwasemphasisedthatregulardatawasbeingreceivedfromMPonly.Inordertostreamlinethe

process, theFollowingCoordiniatingofficers fromutilitieswouldbe responsible for submissionofdata

regularlytoWRPC.

Maharashtra:MrRajurkar

Chattisgarh:MrH.Kdeota

MP:Mr.PKSaxena

It was confirmed in the special meeting that data with respect to Protection Audit, review of zone-3

philosphy ,regarding PMUs, UFR and df/dt relays and other specifics as mandated by the enquiry

committeeshallbefurnishedinthe8requisiteformatsbytheutilitiesalongwiththequarterlyprotection

auditcompliancedata.

HCL

Rectangle

HCL

Rectangle

HCL

Text Box

Annex 8

HCL

Rectangle

HCL

Text Box

Annex 9.1b

HCL

Text Box

Annex 9.1d1

Yours faithfully,

AnQ) eJoUA<Z - rotA 2-~ ~~ v 2Q-".,. ~ d~b...~ I CIIJ 5 CfiHq~ ~Tif 3{f"q; ~ l::t 't J I ()II d1C.S • a; ,

(3'1"1«I' ~ em ~) ~ .:==-POWER GRID CORPORATION OF INDIA LIlVIITED ~ a=-

(AGovernment ofIndia Enterprise) ~ r.oQICOI'( 5

"~.(f,R".3-ft. 9001 : 2000 ~ ~' - "I.S.0. 9001 : 2000 Certified Company"

~ q u;or (IN, C!ST ~, Cf)~d?iOlIJI, ~ 390018(dIvRlCi)s" & e" Floor, VUDA Bha~an, Karelibaug, Vadodara - 390018(G~jarat)

~:/Phone: (0) 0265-2488563, ~:/Fax: 0265-2487542

tJfi'mf m~ ~-II. ~ JOI€41(>14~Western Region Transmission System -II, Regional Headquarters

Ref: WRTS-II/VDR/O&M/AV/260/3 51 }S'88'c? Date: 15 January 2016

~To,

General ManagerWRLDCPlot No. F-3, MIDC Area, Marol,Opp. Seepz, Andheri (East}, Mumbai 400093FAX: 022-28202630

tf. ~. f:t. ~. ~ !WRPC,If(q'q; ~~ !Inward No. /<7 'is'~/Date: ~/2-0/6

Kind Attn: Sh Prithwish Mukhopadhyay

Letter Ref No: - WRLDC/MO-1I1/1726/2016 dtd 14/01/16

Sub: Regarding Auto tripping of 220kV Gwalior Malanpur#1&2 on tripping of 765kV Gwalior Agra#1&2on 14/01/2016.

Dear Sir,

stl~)(.~7'

With reference to the above referred letter, our humble submission is that we have not received clearcommunication from WRLDC/NLDC for blocking the tripping of 220kV Gwalior - Malanpur D/c in theevent of tripping of 765kV Gwalior Agra#1&2 lines. In this regard, vide email dtd 15/09/15 WRLDC hasintimated about increasing the power levels to i) 3600MW when both lines are in service & ii) 2500 MWwhen only one line is in service. The same were implemented at Gwalior S/s accordingly.

However, as per letter dtd 14/01/16, tripping of 220kV Gwalior Malanpur#1&2 on tripping of 765kVGwalior Agra#1&2 lines has been removed with immediate effect. Further, it is requested that a finaldocument covering SPSsettings of 765kV Gwalior Agra D/c line may please be forwarded for needfulaction.

This is for your kind information please.

Thanking you,

~~(0~'amoli) r

GM (AM), WRTS#2Copy to:-For kind information please:1. MS,WRPC-Mumbai2. ED,WR#23. ED(AML CC-Gurgaon4. ED,NLDC- New Delhi

f

~~: off-5, Cfi(1iif ~j'Gf(>f mt<rr, Cf\C:ql~<l1 mm, ~ ~ - 110 016~ .:>.:>

Registered Office: 8-9, Qutab Institutional Area, Katwaria Sarai, New Delhi - 110 016

HCL

Text Box

Annex 9.1d2

Under Frequency Relay Installation

kanchigupta

Text Box

ANNEX 11

Confidential Slide

2

GORAI

2

MSETCL BOISAR

AAREY

GHOD(AIS)

DTPS

VERSOVA

MSETCL BORIVALI

BORIVALI

GHOD (GIS)

GIS BC

SECT-1 SECT-2

GOREGAON

SAKI

MSETCL TROMBAY

TATA BORIVALI

CHEMBUR

METCL Inter-Connection TPC Inter-Connection RINFRA Internal Lines

RINFRA MUMBAI 220KV NETWORK

Confidential Slide

•  FREQUENCY BASED LOAD SHEDDING SCHEME

•  NET IMPORT FROM TPC & MSETCL + BLOCK LOAD

•  TRIGGER TO LOAD SHEDDING: 49+0.5 Hz/sec OR 48Hz

•  LOGIC BUILT IN SCADA FOR AUTOMATIC LOAD SHEDDING

LOAD SHEDDING SCHEME

Confidential Slide

Frequency: 48.5Hz

UF Relay

UF Relay

250 MW 250 MW

GHD

200 MW

DAHANU

MSETCL BOISAR

Load on each Feeder: 20MW

0 MW

Grid Connected

PRESENT LOAD SHEDDING SCHEME

UF Relay

GRI

UF Relay

UF Relay

UF Relay

VSV

GGN

SAKI

ARY

TPC

Net-Import = 440MW

240 MW

AT PRESENT ONE RELAY PER

STATION

0 MW

Total Load : 940MW

Frequency: 48.4Hz Frequency: 48.3Hz Frequency: 48.2Hz Frequency: 48.1Hz Frequency: 48.0Hz

ONE RELAY /STATION

ONE RELAY /STATION

Confidential Slide

RELAY -1

RELAY -2

RELAY -3

&

&

&

OR

TRIGGER FOR LOAD SHEDDING

PROPOSED LOGIC WITH THREE (3) RELAYS / STATION

PROPOSED LOGIC TO TRIGGER LOAD SHEDDING

RELAY -1

RELAY -1

RELAY -2

RELAY -2

RELAY -3

RELAY -3

TWO OUT OF THREE LOGIC FOR INITITATION OF LS

IMPROVES DEPENDABILITY BY ENSURING TRIGGER EVEN DURING NON OPERATION OF SINGLE RELAY

LOGIC IMPROVES RELIABILITY BY AVOIDING TRIGGER DUE TO MAL OPERATION OF SINGLE RELAY

Confidential Slide

Frequency: 48.5Hz 250 MW 250 MW

GHD

200 MW

DAHANU

MSETCL BOISAR

Load on each Feeder: 20MW

0 MW

Grid Connected

LOAD SHEDDING SCHEME WITH THREE RELAYS

GRI

VSV

GGN

SAKI

ARY

TPC

Net-Import = 440MW

240 MW

PROPOSED 3 RELAYS PER

STATION

0 MW

Total Load : 940MW

Frequency: 48.4Hz Frequency: 48.3Hz Frequency: 48.2Hz Frequency: 48.1Hz Frequency: 48.0Hz

3 RELAYS /STATION

3 RELAYS /STATION

UF Relay 1 UF Relay 2 UF Relay 3






Thank You

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