SOUTHERN REGIONAL POWER COMMITTEE - Kar · Minutes of the 42nd PCSC Meeting held on 26-03-2015 Page 1 SOUTHERN REGIONAL POWER COMMITTEE BENGALURU Minutes of the 42nd Meeting of Protection

Minutes of the 42nd

PCSC Meeting held on 26-03-2015 Page 1

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Minutes of the 42nd

Meeting of Protection Coordination Sub- Committee

(PCSC – 42) of SRPC held on 26.03.2015

1. Introduction

The 42nd

meeting of Protection Coordination Sub-Committee (PCSC) was held on 26th

March,

2015 in the Conference Hall of Southern Regional Power Committee, Bangalore. The list of

participants is enclosed at Annexure-I.

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

meeting and briefed them on the following points:

Non-furnishing of tripping details including Disturbance Recorder/ Sequential Event Logger

output in compliance of Regulation 5.2 (r) of IEGC. Fortnightly, under 1.5 (r) of IEGC,

SRLDC is submitting the non-compliance list of trippings for which trip details are pending,

partly submitted or delayed. Members were requested to comply with the Grid code and

CEA Standards in this regard, and furnish/ upload the tripping details within stipulated time.

With reference to Petition No. 374 filed by TANTRANSCO before Hon’ble CERC, all

Southern Region Constituents were requested to adhere to the timeline of 31.03.2015 in

filing the status of implementation of protection audit recommendations in their respective

States to the Commission.

Attention was drawn to NLDC/ SRLDC letter regarding violation of protection standard

(delayed fault clearing) for the month of February, 2015 in case of tripping of inter regional

lines viz., 220 kV Ambewadi – Ponda, 220 kV Talandege – Chikkodi. KPTCL was

requested to take suitable remedial actions to prevent tripping of these lines.

Frequent trippings in NTECL, Vallur - NCTPS area due to insulator related problems on the

transmission towers. TNEB was requested to expedite replacing faulty insulators on the

transmission towers in Vallur and Kalvindapattu areas. With reference to the Meeting held

at Vallur-NTECL plant, the need for implementing and continuing with the measures

recommended such as hot-line washing of the insulators were stressed.

SPS issues discussed in the 105th

OCC meeting of SRPC were briefed; the first issue was

w.r.t. KPTCL’s suggestion of routing SPS trip signal through Kolar-Chintamani-Mallur to

minimize the travel time while restoring SPS-shed loads. The second issue pertained to

modification of SPS at Trichur so as to take Palakkad ICT loading also into account.

ED, SRLDC also expressed the need for devising a SPS scheme for Krishnapatam

Minutes of the 42nd


generation by APGENCO/ APTRANSCO.

22. Confirmation of the Minutes of the 41st PCSC meeting held on 26-02-2015

SE (Protection), SRPC stated that the Minutes of the 41st meeting of the PCSC had been

circulated vide SRPC letter No. SRPC/SE-III/ PCSC·41/ 2015/ 1702 – 133 dated 16.03.2015.

However, as it was noticed that a typographical error had occurred in the recommendations

relating to the grid disturbance on 220 kV Sedam –Tandur line given at Sl. No. I (4) of the

Annexure-II to the Minutes, the recommendations given therein were corrected as follows:

KPTCL to provide Bus bar and LBB protections for 220 kV bus at Sedam S/s. KPTCL to implement A/R feature on 220 kV Sedam-Tandur inter-state line.

With this, the Minutes of the 41st meeting of the PCSC were confirmed.

3. Details of Grid Disturbances (GD’s), Grid Incidents (GI’s), Line Trippings due to PLCC

mal- operation, Auto-Reclose non-operation

The trippings due to GD’s, GI’s, PLCC mal-operation and Auto–Reclosure failure/non-

operation that had occurred during the period February - March, 2015 were discussed in the

Meeting. The deliberations and recommendations of the PCSC-forum are enclosed at

Annexure–II.

4. Status of pending PCSC recommendations

The status of implementation of pending PCSC recommendations were discussed in the

meeting. The constituents have been requested to kindly submit the status of their compliance

latest by 24.04.15. The updated status of the same as on 16.04.2015 is enclosed at

Annexure III.

5. Remedial measures/ Action taken for the tripping incidents of the transmission elements

under forced outage

The tripping incidents of the transmission elements under forced outage for which the remedial

measures/ actions taken still awaited were discussed in the Meeting. The Constituents have

been requested to kindly furnish the remedial measures/ action taken in time so as to forward

the same to Central Electricity Authority. The updated list of the same as on 16.04.2015 is

enclosed at Annexure-IV.

7. Certificate for Healthiness of Batteries

As per the MoP/ CEA direction given in pursuant to recommendations of the Enquiry

Committee (NEW grid disturbance on 30th

& 31st July, 2012), RPC’s are required to obtain

from their respective Constituents the monthly certificate for healthiness of batteries, installed

at 220 KV and above voltage level Substations (for power supply to Relays, RTUs and PLCC

equipment) and furnish the same to CEA/ MoP.

With reference to above, the Constituents have been requested to submit the certificate on

Minutes of the 42nd


healthiness of batteries on monthly basis (i.e. status for a month may be sent by the 7th

day

of the succeeding month) to SRPC.

The Constituents have been requested to furnish station-wise status as per the format given

below:

Sl. No.

Station Application Battery Battery Charger Remarks

Station Name

Code Type

(PS/ SS)

Protection/

Communication

Details Status (Healthy/ Unhealthy)

Details Status (Healthy/ Unhealthy)

1 Station-A Protection (Bank-1)

Protection (Bank-2)

Communication (Bank-1)

Communication (Bank-2)

2 Station-B …

Note: 1. Code is the short name of the Station

2. PS – Power Station; SS - Substation

The sought status for the month of February, 2015 has not been received from the following

SR-Constituents:

TSGENCO (Thermal & Hydro), JSWEL & GMR.

9. Dynamic study data submission

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

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

have been requested to submit the Dynamic study data at the earliest.

10. Network configuration changes

As per the information furnished by SR-Constituents to the OCC forum in their 105th

Meeting held on 10.03.2015 (Minutes circulated on 28.03.2015), it is observed that no

network configuration changes (additions/ deletions/ modifications of transmission elements)

took place in southern grid during the month of February, 2015.

KPTCL vide their mail dated 25.03.2015 informed that the following new transmission

elements had been added in the month of March, 2015.

Sl.No.

Name of the Element

Connected Sub Station

Date and time of Commissioning

Remarks

1 220kV Hiriyur-Gowribidanur

D/C line

Hiriyur PGCIL and Gowribidanur SS

4.3.2015 at 21.10 and 21.15Hrs

Load taken on 9.3.2015 at 21.22

and 21.26Hrs

2 63MVAR Bus Reactor 400kV SS Guttur 23.03.2015 at 15.57Hrs

Minutes of the 42nd


11. Compliance of Hon’ble CERC Orders

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

Compliance of Regulations 5.2 (r) of the Grid Code: Issue regarding non-

furnishing of FIR / Trip Analysis Report, EL, DR, etc. was also

highlighted. It is pointed out that the above reports are to be submitted /

uploaded on SRLDC web application within 24 hours as mandated under

IEGC / CEA Regulations.

Implementation of Phase-I and Phase-II of Protection Audit

Recommendations: All the constituents are requested to submit the updated

status of the compliance (those who have not completed recommendations

mentioned in the Phase I and Phase II) to SRPC Secretariat at the earliest.

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

petition/affidavit to SRPC Secretariat at the earliest: APTRANSCO.

Compliance of Regulations 5.2 (e) & 5.2 (l) of the Grid Code and Regulation

3(1)(e) of CEA Grid Standards: The constituents are requested to strictly

comply with these provisions by ensuring standard protections systems having

the reliability, selectivity, speed and sensitivity to isolate the faulty equipment

and protect all components from any type of faults, within the specified fault

clearance time and providing protection coordination

Ensuring proper maintenance of transmission lines and adopting best O&M

practices: The constituents are requested to conduct line patrolling regularly

as per the SRPC transmission line patrolling guidelines (available under the

menu item "All Uploads Operation Miscellaneous Transmission Line

Patrolling Protocol / Guidelines for Southern Region" on SRPC website).

(http://www.srpc.kar.nic.in/website/2014/operation/patrolling.pdf).

11.2 Petition No. 167/Suo- Motu/2012: Order dated 22.02.2014

The Constituents are requested to follow approved protection philosophy

ISTS licensees are requested to submit details of updated distance protection relay

setting of all inter-regional lines to POSOCO & RPCs.

All SLDCs are requested to install/activate sound recording system in their control

rooms within three months from the date of issue of this order.

The Constituents are requested to submit the progress of implementation to

SRPC and SRLDC as specified in the Hon'ble CERC Order.

11.3 Petition No. 263/MP/2012: Order dated 19.12.2013

Constituents are requested to implement the quantum of relief by AUFR and df/dt

relays by identifying additional feeders and keep them functional within one month

of issuing this order.

SLDCs are also requested to map these relays on their respective SCADA

system within three months of issuance of this order.

The Constituents are requested to submit the progress of implementation to

SRPC and SRLDC as specified in the Hon'ble CERC Order.

11.4 Petition No. 374/MP/2014: Date of hearing 15.01.2015

http://www.srpc.kar.nic.in/website/2014/operation/patrolling.pdf

Minutes of the 42nd


All Southern Region Constituents had been directed to file the status of

implementation of protection system in their respective system to Hon’ble

CERC by 31.03.2015.

12. Date & Venue of the next Meeting

It is informed that the 43rd

PCSC meeting will be held on 29.04.2015 (Wednesday) at 10.30

hrs at SRPC Secretariat, Bengaluru.

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

ANNEXURE- I

1 PCSC-42

ANNEXURE- I

2 PCSC-42

ANNEXURE- I

3 PCSC-42

ANNEXURE- I

4 PCSC-42

ANNEXURE- I

5 PCSC-42

ANNEXURE- I

6 PCSC-42

1 Grid Occurrences of 42nd

PCSC Meeting held on 26-03-2015

Grid Occurrences

I. GRID DISTURBANCES (GD):

1 Complete outage of 220kV Sedam substation of KPTCL

(i) Date and Time of Event 15-02-2015 at 14:24 hrs

(ii) Location 220 kV Sedam substation

(iii) Plant and/or Equipment directly involved

(iv) Reported Disturbance / Fault

Fault occurred in 220kV Sedam-Shahpur line

(v) Load Loss 100 MW

(vii) Category GD-1

SLD:

Deliberations:

KPTCL:

The fault occurred in 220kV Sedam-Shahpur line.

At Sahapur end, line tripped on zone-1 distance protection and fault loop R-N was at 23 km.

At Sedam end, distance (in zone-2) and back up protection relays on Shapur line sensed the fault and picked up but before their tripping operation, DC supply was lost and hence relays could not operate. (Earlier it was suspected as mechanical

220 kV

Tandur

(TSTRANSCO)

Sedam (KPTCL)

Raichur Shahpur Humnabad

110 kV

Z-2

Z-2

(sense

only)

Z-1

Z-2

DC supply failure;

no LBB;

bus dead

Z-2

ANNEXURE-II



latch problem with CB).

Due to absence of LBB protection at Sedam, all remote ends - RTPS lines (1&2) and Tandur line - tripped in Zone-2 distance protection. Since the RTPS, which is the main source, is lost, bus dead/shutdown condition occurred at Sedam.

220 kV Tandur inter-state line was chand-tripped at Sedam.

In Hummnabad and RTPS bays, DC earth fault occurred due to damaged DC cable that resulted in tripping of MCB for main DC supply. It is suspected that due to earth potential rise on account of fault, the faulty DC cables might have got grounded causing DC earth fault that made main DC MCB to trip.

KPCL:

220/110 kV ICTs did not trip at Sedam end due to the fact that 110 kV side of ICTs are radially feeding the lines.

SRLDC:

No B/C is at Sedam and it is a single bus operation.

SLDC should check the status/nature of the faults and the line should not have been charged without identifying the root cause, and attending to it.

DC grounding issue at RTPS bay shall be completed by tomorrow (i.e. 27.03.2015).

A/R to be provided on Sedam –Tandur interstate line.

KPTCL should coordinate with both TSTRANSCO and APTRANSCO to provide A/R feature on the 220 kV Sedam –Tandur and Alipur – Regulapadu inter-state lines.

KSEB:

In general, during shift changeover, positive to earth and negative to earth voltages are being recorded.

Remedial measures taken at Sedam end by KPTCL: DC problem:

o Complete testing of DC circuit was taken up with the help of M/s Tarus, and would be completed by 27.03.2015.

o On line DC e/f locator is being used for troubleshooting. o DC cable problem at Hummnabad bays were attended. o At RTPS bays, the damaged control cables would be replaced by April, 2015 end

after availing LC. o Two lamps have been installed at the substation that would indicate DC

grounding/ earthing problem. o There are 2 batteries and 2 chargers but with only one DC load bus; Changeover

of DC source is being carried out manually. To have dual DC load-bus feature, tendering is under process; tenders have been evaluated; and it would take around 12 months time for execution.

Due to non-availability of carrier, zone-2 time delay of distance relays has been reduced from 0.35 sec to 0.2 sec.

There was no problem in the Tandur bay at Sedam, and CB, 86 relay and other relays were tested and found to be OK.

Tendering for the activities covering protection audit recommendations in 93 substations, viz., LBB protection, Bus bar protection, dual DC supply, A/R feature on interstate lines, etc. is in progress.

Shift Engineers working at Sedam are on contract basis; and they reset main MCB of main DC source once it is tripped; they do not report adequately the problems at the station. They have been instructed to adhere to the standard operating

ANNEXURE-II



procedures. Recommendations:

KPTCL to provide Bus Bar protection and LBB protection at Sedam S/s and furnish the status of their implementation to PCSC forum.

KPTCL to implement A/R feature on 220 kV Sedam-Tandur inter-state line.

2 Complete outage of 220kV Ambewadi substation of KPTCL


(ii) Location 220 kV Ambewadi Substation



Fault in 220kV Ambewadi-Nagjheri line-2

(v) Load Loss Nil

(vii) Category GD-1

SLD:

Deliberations:

KPTCL:

A Y-B-E fault occurred in 220kV Ambewadi-Nagjheri line-2 due to snapping of conductor. The distance protection at both ends sensed the Y-B-E fault on the line. The

breaker at Nagjheri end got tripped and fault was cleared from Nagjheri end. The CB at Amewadi did not trip as it was under lock-out due to low air pressure.

As the 220 kV Ambewadi station is on a single bus operation and LBB protection is not available, it resulted in tripping of remote ends (Nagjheri-1, Narendra-1 & 2) in Zone-2 distance protection.

220/110 kV ICT-1 at Ambewadi station tripped on operation of back up directional earth fault protection on LV side. 220/110kV ICT-2 at Ambewadi

220 kV Ambewadi

Ponda Nagjheri Narendra

110 kV

No trip;

radial Z-1

no trip;

no LBB;

bus dead

Z-2

1 2

Z-1

Z-2

backup

DEF trip

CB

lockout 1 2

under

shut

down

ANNEXURE-II



station was not in service at the time of disturbance. 220 kV bus at Amewadi became dead because there is no feed from Ponda

(radially fed), Nagjheri (tripped), Narendra (tripped) and 110 kV bus which is fed by Supa HEP (ICT tripped).

Ponda 1 & 2 lines were hand-tripped at Ambewadi.

At Ambewadi, bus isolators have been made ready; bus coupler is ready; PT is yet to be replaced; afterwards split bus would be implemented.

At both the ends of Ambewadi – Ponda line, PLCC equipment have to be provided.

One wave trap is by-passed at Ambewadi; On Narendra and Nagjheri lines PLCC system is in place.

SRLDC: PLCC panels are there at Ambewadi, but protection couplers have to be installed.

A/R is to be provided on Ambewadi – Ponda 1 & 2 lines. KSEB:

In case of low air pressure, CB first goes to alarm stage; and if the air pressure further drops, only then does it go to lock-out stage.

Remedial measures: Operation of the compressor was checked. The issue of no annunciation/ alarm observed during the CB lockout has been

attended. Recommendations:

KPTCL shall provide A/R feature on Ambewadi – Ponda 220 kV D/C inter-state line.

Till the completion of R&M works for bus bar and LBB protection, KPTCL shall explore the possibility of having split bus operation at Ambewadi and submit the details of the same to PCSC forum.

3 Complete outage of Upper Sileru Hydro power station


(ii) Location Upper Sileru Hydro Power station (USHPS)



LBB of Unit-4 got operated

(v) Generation/ Load Loss Nil

(vii) Category GD-1

Set up:

USHPS is equipped with 4x60 MW hydro generators, 75 MVA, 220/11kV GTs (four nos.), three 220 kV feeders [Balimela (inter-regional link), Donkarai, and Pendurthy] and one Station Transformer (25 MVA, 220/33 kV).

The station is equipped with two buses named main bus and transfer bus. There is a bus coupler between main and transfer buses and also there is a bus sectionalizer CB on the Transfer bus and bus sectionalizer isolator on Main bus. However

ANNEXURE-II



Transfer Bus is also being used as main bus through Transfer bus sectionalizer CB and Bus coupler CB. Functionally station is operating on single Bus.

Unit-1 & 2 connected to main bus and Unit-3 & 4 connected to transfer bus.

220 kV line feeders and the station transformer (ST) are connected to Main bus.

SLD: Upper Sileru HPS

E

Deliberations:

USHPS, APGENCO:

At the time of de-synchronizing U#4, the B-phase limb of the CB did not open. As a result, PD Relay operated to trigger LBB protection trip of all the CBs (connected to main and transfer buses) and B/C. Hence, 220 kV bus at USHPS became dead.

As the generator protection system of Unit#4 is a static relaying system, the events and disturbances are not available with the station for the above trip.

PD relay setting was kept as 200 msec.

Remedial Measures: o CGL breaker limb control valve C&D roller was found to be faulty and was

replaced with new spare. (It was also noted that the same valve was replaced recently for the same problem occurred earlier).

o LBB scheme was modified in such a way that whenever LBB protections are acted upon G#3/G#4, only G#3, G#4, Transfer bus sectionalizer, and bus coupler are tripped instead of all breakers.

4 Complete outage of Srisailam left bank hydro power station

Main bus

GT:

75 MVA

60 MW

Balimela

G1

G2

G3

G4

60 MW

GT:

75 MVA

Transfer bus

Donkarai

Pendurthy

ST: 25 MVA,

220/33 kV

B/C

B/S

220 kV

ANNEXURE-II




(ii) Location Srisailam Left Bank Hydro Power station



Fault in GIS bus at Srisailam. 400kV

Mamidapalli-1&2, Satenapalli-1&2 and

Kurnool lines tripped on operation of residual

over current protection at Srisailam.

(v) Generation/ Load Loss Nil

(vii) Category GD-1

SLD: SrisailamLB

Deliberations:

TSGENCO:

There was no generation at Srisailam left bank during the incident.

There occurred a fault in 400 kV GIS bus i.e. problem in one of the bus side isolators of the lines.

As the bus bar protection was not available, it was sensed by residual over current protection provided in the distance relay of 400kV lines at Srisailam which in-turn led to the tripping of the line breakers of all 400kV lines (given below) at Srisailam: 400kV Srisailam-Mamidapalli line-1&2 400kV Srisailam-Satenapalli line-1&2 400kV Srisailam-Kurool

Remote ends of Satenapalli-1&2 and Mamidapalli-1&2 lines were holding and they were later hand-tripped.

Residual current

protection trip of lines

GT

Mamidipally Satenapally Kurnool

G1

G2

G3 G4 G5 G6

400 kV (GIS bus)

No generation;

no condenser mode

operation

hand trip

O/V, St-1 trip

Stn.Trf.

ANNEXURE-II



Remote end of Kurnool line tripped on operation of over voltage, state-1 protection.

The residual over current relay mal-operated due to moisture in SF6 gas. The levels of moisture absorbents for the gas checked and refilled. There is no online dew point monitoring system.

No condenser mode of operation is at SSLM-LB.

Numerical Bus Bar protection would be installed in a month. Bus bar protection would be with two zones covering each bus independently.

SRLDC:

In the past, there were leakage current issues (4 times) and O/V issue (1 time).

As there is no shut down request from TSGENCO for SSLM in April/May, it is not clear how the relays would be installed in a month’s time there.

Time frame for commissioning of numerical bus bar protection shall be furnished by 20.04.15.

KSEB:

Bus coupler CB is generally provided with O/C and E/F relay.

SRPC:

TSGENCO has not yet furnished the reasons and remedial measures taken in respect of the grid incident that occurred at SLBHES on 23-01-2015 at 16:10 hrs (discussed in PCSC-41).

Recommendations:

TSGENCO to provide bus bar protection at Srisailam left bank HES, and furnish the time frame for implementation of the same by 20.04.2015.

5 Complete outage of 220 kV Tadikonda substation of APTRANSCO


(ii) Location 220/ 132 kV Tadikonda Substation



B-phase CT failure on LV side of 220/132kV ICT-1 at Tadikonda led to complete outage of Tadikonda station.

(v) Generation/ Load Loss Load loss = 200 MW

(vii) Category GD-1

SLD: Tadikonda

ANNEXURE-II



Deliberations:

APTRANSCO:

Triggering incident was the failure of B-ph CT on LV side of 100 MVA, 220/ 132 kV ICT -1. Due to this, there was a slow developing fault on the LV side of ICT-1, and it resulted in the tripping of the following elements: 100 MVA, 220/ 132 kV ICT-1 tripped on differential protection 100 MVA, 220/ 132 kV ICT-2 tripped on over current protection 160 MVA, 220/ 132 kV ICT-4 tripped on over current protection 220 kV Bus coupler tripped on over current protection 220 kV Tadikonda – VTS line 1 tripped at VTS end on distance protection, zone-

4.

As the 220kV Ongle-Tadikonda line was kept idle charged from Ongole during the instance, it led to complete outage of Tadikonda Substation.

VTS line impedance is around 10 ohm per circuit and that of Ongole is around 4

ohm. As the parallel impedance of circuits and ICTs between relaying point and the fault point seen at the relaying point is around 10.5 ohm, the zone-4 might have got operated at VTS end on 220 kV Tadikonda – VTS line 1.

The 100 MVA, 220/ 132 kV ICT-3 and 220 kV VTS –Tadikonda line 2 did not trip during the incident.

There were no numerical relays at Tadikonda, as such no DR/EL could be furnished.

The distance protection philosophy being followed by APTRANSCO was explained as follows: Z1 (forward) –> 85 % of Protected line (Instantaneous)

Bus-I

Bus-II

220 kV

132 kV

Guntur

Nallapadu

Marripalem

Piduguralla

Tadepalli

VTS-1

VTS-2

Ongole

B/C

(line idle charged)

CT fail

1

2

3

4

Z-4 trip

charged)

Z-4 trip

charged)

Diff. trip

charged)

O/C trip

charged)

O/C trip

charged)

2 x 31.5 MVA

charged)

33 kV O/C trip

charged)

ANNEXURE-II



Z2 (forward) – > Protected line + 50 % of Shortest Line (0.3 sec) Z3 (forward)– > Protected line + 120 % of Shortest Line (0.6 sec) Z4 (forward) –> Protected line + 120 % of Longest Line (0.9 – 1.2 sec) Z5 (reverse) –> 25 % of Z1 (1 sec)

Remedial measures: It has been proposed to reduce O/C relay setting of the ICT’s to 0.9 sec from

the present 1.0 sec after checking the fault level calculations..

Recommendations:

Reasons for non-tripping of ICT-3 along with remedial measures taken shall be furnished by APTRANSCO to PCSC forum.

II. GRID INCIDENTS (GI):

Sr.

No.

Details of Events Date and Time Reason Category

1 Tripping of 400kV Coastal-

Tuticorin PS line 19-02-2015 at

16:37 hrs

Line tripped at Coastal end only

due to suspected PLCC mal-

operation and was holding from

Tuticorin PS end. Running Unit at

Coastal energen also got tripped

during the event.

GI-2

Deliberations: CEPL:

The 400 kV CEPL – Tuticorin PS line tripped at CEPL end due to DT receipt from Tuticorin PS.

When the tie-CB trips at Tuticorin PS, it should not be extended to CEPL.

SRLDC:

400kV CEPL-Tuticorin PS line tripped at 16:37 hrs Line tripped at Coastal end only, and was holding from Tuticorin PS end. During the instance, 400kV NTPL-Tuticorin PS was under shutdown due to

insulator replacement works. Running Unit at CEPL also got tripped during the event.

Coastalgen TPS NTPL

DT

hand trip

under S/D

unit trip

ANNEXURE-II



Subsequently, 400kV Coastal-NTPL line was manually tripped from Coastal end at 16.37 hrs.

End-to-end testing may be carried out to ascertain PLCC operation.

In addition, level measurement and wiring check have also to be carried out.

Recommendations: PLCC end-to-end testing shall be carried out by CEPL and Tuticorin PS (PGCIL-SR II) by

06.04.2015.

2 Tripping of 220kV

Chikodi-

Talandage and

220kV Chikodi-

Mudshingi line

20-02-2015 at

06:40 hrs

Lines tripped during test charging 220kV

Chikodi-Belgaum line-2 from Chikodi

end.

GI-1

Deliberations:

KPTCL:

At 3.20 hrs, the 220kV Belgaum-Chikodi-2 line tripped on distance relay,zone-1 (Fault loop RN, 63.7Kms)

After approval from LDC, the 220KV Belgaum-Chikodi-2 line test charged at 6.40Hrs in the morning. However, due to insulator decapping, Mudashinge, Talandage lines tripped. It was observed that the Chikkodi end CB on Belgaum – Chikkodi 2 line did not open during the incident.

Chikkodi- Mudashinge line tripped in Zone 3 at Mudashinge end (DPR,zone-3, R phase, Dist- 125.5Kms, L1- 1.49KAmps, L2-0.15KA, & L3-0.29KA). Breaker at Chikodi end was in closed condition.

220KV Chikkodi-Talandage line tripped at Chikkodi end on DEFR (due to problem in the directional element, the relay had been made non-directional). Talandage end CB did not trip.

Remedial measures: At Chikkodi, VXL make old C&R panels are in service. Relays are giving frequent

troubles. Hence 2 numbers of alternate C&R panels are arranged at Chikkodi. Replacement of C&R panels of Mudashinge and Talandage lines is scheduled during 18th, 19th, and 20th of April, 2105.

SRLDC:

All inter-state lines are being monitored by NLDC.

PLCC problem along with A/R feature have to resolved.

Recommendations: KPTCL to provide A/R feature on the 220 kV Chikkodi – Talandage, and 220 kV Chikkodi –

Chikkodi

Belgaum

Mudshinge

Talandage

1

2

Z-3

DEFR

trip due to insulator

decapping

ANNEXURE-II



Mudashinge inter-state lines. KPTCL to carry out E/F relay coordination for Chikkodi - Talandage and Chikkodi –

Mudashinge lines in coordination with Maharashtra.

3 Outage at

Regulapadu

station of

APTRANSCO

21-02-2015 at

00:49 hrs

Y-Ph Metering PT failed at 220KV

Ragulapadu Substation. Fault got cleared

by tripping of lines from remote ends.

Deliberations:

The cause of the incident was the failure of Y-Ph metering PT at Regulapadu.

The 220 kV Regulapadu – Gooty (AP) line tripped at Gooty (AP) in Zone-2.

The 220 kV Regulapadu – Alipura line tripped at Alipura in Zone-2. SRLDC:

As per synchrophasor data at 400 kV Gooty S/S, it was observed that two faults had occurred, first in R-phase and 2nd in R-B phase.

Status of bus coupler breaker and Bus bar protection at Regulapadu station was enquired.

Alipura – Regulapadu being an inter-state line, A/R feature should be put in place. APTRANSCO:

Fault was cleared at remote ends due to non-availability of BB protection.

Provision has been given in DPR for addressing single bus operation issue, and BB protection issue.

SRPC:

The status of features such as PLCC, A/R, double bus system, LBB protection, Bus bar protection, and the protection philosophy being followed (Main-1/ Main-2/ Back-up), for all inter-state and inter-regional lines shall be obtained from the Constituents.

Recommendations: APTRANSCO to furnish the remedial measures taken in consequent to the tripping

incident along with the status of bus bar protection and bus coupler at Regulapadu S/s. A/R feature to be enabled on Regulapadu – Alipuira 220 kV inter-state line.

4 Tripping at 230kV

Theni substation

22-02-2015 at

13:12 hrs

Fault had occurred in 230kV Theni-

Chekanoorani feeder.

GI-1

Regulapadu

Alipura

Gooty

Z-2

Z-2

metering PT

ANNEXURE-II



5 Tripping of 400/220kV

ICT-2 at Bidadi

substation

22-02-2015 at

16:58 hrs

ICT-2 got tripped on operation of backup

protection during B-phase LA failure of

ICT-1 at Neelamangala station of KPTCL

GI-2

Deliberations:

As per FIR/TR of Bidadi (PGICL, SR-II), B-phase LA failed on 400 KV side of ICT-1 at Nelamangala Substation. As Bidadi ICT-2 also fed this fault from 220 kV side, it tripped on backup over current protection (on both HV and LV sides). PGCIL:

230 kV directional O/C relay did not get voltage input from bus CVT because of its fuse blown condition, hence the relay mal-operated.

SRLDC:

Reason for operation of back-up protection for ICT-2 at Bidadi was not clear as there was no delayed clearance of the fault.

PGCIL to give report on the incident.

A visit to Bidadi station should be made to know the details. SRPC:

PSAG visit shall be made to ascertain the status of the protection system at Bidadi s/s. Recommendations:

PGCIL (SR-II) to submit a detailed report on the incident along with remedial measures taken to PCSC forum in a week’s time.

6 Tripping of ICT-1 at

Nelamangala

substation of KPTCL

22-02-2014 at 16:58

hrs on

ICT-1 at Nelamangla station got tripped

due to failure of B-phase lightening

arrester.

Deliberations:

A Y-Ph to ground fault occurred on Theni- Chekanoorani feeder and tripped at 13.10 hrs. (ref: FIR of Theni)

The line tried to Auto-Reclose, but due to the persistent nature of the fault, the line was permanently tripped at both ends. However, due to the problem in Y-Ph limb of Theni end CB, LBB Protection operated at 230 kV bus of Theni S/s. As Theni is operating on single 230 kV bus, all the connected 230 kV lines also got tripped.

Remedial measures: Faulty limb of CB has been attended and replaced by TANTRANSCO. Theni – Sabarigiri (Mooliyar) feeder normalized at 13:58 hrs. on 22.02.2015. Theni – Checkanoorani feeder normalized after testing the breaker on 22.02.2015 at

22:11 hrs. SRLDC:

Timeline for provision of bus coupler breaker at Theni S/S may be provided. SRPC:

As per DR of Theni, the fault took place at 13.04.46 hrs. Time synchronization with GPS may be checked at Theni S/S.

ANNEXURE-II



Deliberations:

KPTCL:

ICT-1 at Nelamangala S/S got tripped on differential protection due to failure of B-phase

lightening arrester.

Remedial measures:

Failed lightening arrester was replaced

SRLDC:

The fault was cleared in time.

7 Tripping of 400kV

Jeypore-Gazuwaka line-

1&2 and tripping of

HVDC back to back pole-

1&2 at Gazuwaka

23-02-2015 at

13:34 hrs on

HVDC pole-1 got tripped due to failure

of 4 no. power supply card. HVDC

pole-2 tripped on DC low voltage trip.

400kV Jeypore-Gazuwaka line-1&2

tripped due to operation of Over voltage

protection at Gazuwaka end.

GI-2

Deliberations:

As per FIR submitted by HVDC, Gazuwaka station, power flow on pole-2 was being reduced as per instructions from NLDC due to system constraint in eastern region.

HVDC pole-1 got tripped at 13:33:49 hrs due to failure of 4 no. power supply card of YDUV valve.

400kV Jeypore-Gazuwaka line-1&2 tripped at 13:39:57 and 13.39:58 hrs respectively due to operation of Over voltage, Stage- I protection at Gazuwaka end due to load throw – off on tripping of few lines on eastern side. (and DT sent to Jeypore end)

HVDC pole-2 tripped at 13:34:00 hrs on DC low DC voltage trip due to tripping of both 400kV lines.

PGCIL (SR-I):

It was observed that there were voltage fluctuations at Jeypore at the instant of failure of control supply cards, and the matter has been referred to OEM (M/s ABB) for remedy.

It was further observed that voltage fluctuations on Jeypore-Gajuwaka line were being experienced whenever FSC was in service/ put into operation at Jeypore end.

Remedial measures: The failed control supply cards were replaced. The matter has also been taken up with M/s ABB.

East bus South bus

Jyepore (Odisha)

1

2

P2

HVDC Pole-1 trip

due to ‘PS card

failure'

FSC

P1

Gajuwaka HVDC B2B (AP)

HVDC Pole-2 trip

due to ‘low DC

voltage’

AC lines tripped

due to O/V

ANNEXURE-II



SRLDC:

As per the present design, FSC at Jeypore would get disabled/ bypassed if the power flow on Jeypore-Gajuwaka line goes below 300 MW. However, if the PGCIL (SR-I) wants this limit to be changed, the same should be intimated to NLDC.

Recommendations: PGCIL (SR-II) to submit the report of M/s ABB’s on preventing supply card failures.

8 Tripping of HVDC

Talcher-Kolar pole-1

23-02-2015 at 15:37

hrs

Pole 1 of Talcher-Kolar HVDC

Transmission system tripped on receipt

of ESOF (Emergency Switch-off) from

Talcher

GI-2

Deliberations:

SRLDC:

Pole 1 of Talcher-Kolar HVDC Transmission system tripped on receipt of ESOF (Emergency Switch-off) from Talcher.

Antecedent Bipole power: 1000 MW

It changed over to Metallic Return mode, and the final DC power in Pole 2 settled at 997 MW (Talcher AC side).

Since Pole 2 compensated for the power and as there was no power loss, SPS was not triggered which is as per design.

PGCIL (SR-II):

As per their information, ESOF signal was received at Kolar due to filter protection operation at Talcher.

Filter protection at Kolar might have got operated due to oil leakage in filter capacitor

banks. Recommendations:

PGCIL (SR-II) to submit a report on the reasons for operation of filter protection at Talcher, and subsequent receipt of ESOF at Kolar.

9 Tripping of 765/400kV

ICT-1 at Raichur

25-02-2015 at

18:32 hrs

ICT-1 at Raichur tripped due to mal-

operation of contact multiplication relay

GI-2

Deliberations:

PGCIL (SR-II):

ICT-1 got tripped on operation of spare ICT top oil temp protection.

The tripping got extended via 30K CMR relay. This relay did n’t have any cable from the field as no TBs were identified for top oil temp protection in TBEA Xmer. However, the CMR operated and resulted in extending Binary Input signal to P645 and caused operation of Gr-A & Gr-B relays tripping ICT-1.

There is an NRV between conservator and Tank. Recommendations:

PGCIL (SR-II) to disable the top oil temperature protection in the concerned relay at Raichur-PG and Tiruvalam-PG also.

ANNEXURE-II




Gajwel substation

27-02-2015 at 2:32

hrs

ICT-3 tripped due to operation of over

current relay

Deliberations:

TSTRANSCO:

The insulation of the cable laid from tie-CT to relay panel (leads pertaining to Y-phase tie-CT) got earthed at the marshalling box near the cable gland causing circulating currents in the neutral. This caused HV side back-up over-current relay to operate tripping ICT-3.

Remedial measures: The cable which was causing undesirable tripping was replaced on 28th February-

2015 and the currents displayed in the numerical relay were found to be balanced and same as that of LBB and differential relays.

SRPC:

The cause of cable failure may be investigated.

EL uploaded was the same as DR.

11 Tripping of 220 kV

Chikodi-Talandage and

Chikodi-Mudshingi

line

01-03-2015 at 3:37

hrs

220KV Chikodi-Talandagi & 220KV

Chikkodi-Mudashingi lines tripped from

Talandage and Mudshingi due to

400KV Karad line fault

GI-1

Deliberations:

KPTCL:

At 3.35 hrs., 220kV Chikkodi - Talandagi & 220kV Chikkodi - Mudashingi lines tripped from Talandage and Mudshingi due to fault on 400kV Karad line (in Maharashtra).

Subsequently around 4.15 hrs., the 220KV Belgaum-Chikkodi-I & II lines were hand tripped at 220KV Chikkodi end and 220 kV Belgaum R/S has taken KPTCL Supply from 220KV Narendra line ( Both 220KV Belgaum-Chikkodi-I & II lines GOS Opened & CB OFF at 220KV Belgaum end).

Then, Chikkodi – Mudushingi line test charged at 4.44 hrs., but tripped on DPR, zone-1, YN, 26.5 km from Mudushingi end. It was observed that Insulator got de-capped at location 232 and 238 of the line.

Remedial measures: Chikkodi – Mudushingi line charged after attending the line fault. Chikkodi – Talandage line charged as per SLDC instructions.

12 Tripping of 400kV

Neelamangala-Mysore

Line-2

01-03-2015 at 2:19

hrs & 18:01 hrs

Line tripped on operation of over

voltage protection at Nelamangala end.

Suspected faulty Y-phase CVT had

caused the tripping.

GI-2

Deliberations:

SRLDC:

On both the occasions, the line tripped due to Over Voltage, Stage-I operation at Nelamangala end and due to DT receipt at Mysore end from Nelamangala.

Suspected malfunctioning of either Over Voltage Stage 1 Relay or Y-Phase CVT. KPTCL:

Bays at Nelamangala are being maintained by PGCIL (SR-II) PGCIL (SR-II):

Over voltage relays were swapped for Stage-1 and Stage-2.

Remedial measures:

ANNEXURE-II



Action has been taken to set Stage-1 (110%) relay setting to Main 1 protection REL - 521 & Stage -2 (140%) relay setting for External O/V relay.

Y-Phase CVT of Mysore Line 2 was replaced by spare one at Nelamangala.


Neelamangala-Mysore

Line-1

02-03-2015 at 23:30

hrs

Line tripped on operation of over

voltage protection at Neelamangala end.

GI-2

Deliberations:

As per TR (Trip Report) of Mysore,

Over voltage protection operated at Nelamangala end and direct trip was received at Mysore.

KPTCL:

Drop out to pick up ratio was tested recently.

The voltage was 243 kV and over voltage stage-I got operated. SRLDC:

Operation of Overvoltage protection could not be established as D.R/ E.L of Nelamangala station were not furnished.

Recommendations: PGCIL (SR-II) to check OVR operation at Nelamangala.

14 Tripping of ICT-1, 2

at Trissur substation of

KSEB

03-03-2015 at 17:02

hrs

Bus-bar protection got operated at

Trissur substation

GI-2

Deliberations:

KSEB:

On 03.03.15 at 9.02 hrs, ICT-3 tripped due to a close-in fault near Madakkathara (Trissur).

On the same day, while testing the relays meant for ICT#3, LBB protection (which was not kept disabled previously) got initiated.

As the LBB is routed through BB protection, a misplaced lead wire connection from CRM module of BB protection panel initiated a tripping signal to ICT – 1 & 2.

The relays of ICT # 1and # 2 at 400 kV Substation, Madakkathara are static and old relays. Hence no DR/EL could be furnished.

Remedial Measures: The rectification was done on 04.03.2015. Replacement of old relays with new numerical relays are under progress.

15 Tripping of

400/220kV ICT-2

and 3 at Hoody

substation of

KPTCL

3-03-2015 at

23:44 hrs

Mal-operation Oil surge relay GI-2

Deliberations:

KPTCL:

ICT#2 trip: The B-ph Transformer has been kept idle since its failure on 18.4.2014. The OLTC

Bucholtz 'B phase' (OSR) relay has malfunctioned.

ANNEXURE-II



Remedial measures: 1. The control cables of B-Ph have been checked up and insulation tape put to each core. 2. Further the auxiliary relays of B-ph Transformer have been taken out to avoid any malfunctioning.

ICT#3 trip: Due to heavy rain, moisture had got collected near the trip terminals of 'Y' phase OSR

relay. ICT-3 also got tripped due to operation of OSR relay of Y-phase transformer. Remedial Measures:

1. Moisture contents cleaned and dried from trip terminals of 'Y' phase & terminals have been tightened. Utmost care taken to prevent further entry of moisture.

16 Tripping of UNIT- 3

& 5 at Jindal power

station

08-03-2015

19:41hrs

Units tripped due to tripping of SUT. GI-2

Deliberations:

Triggering incident:

B-Phase LA flashover occurred at Lingapur end on Lingapur – Munirabad-PG 220 kV line-2

JSWEL:

As per JSWEL SPS, whenever the voltage at 220 kV bus drops below 78 % of the normal phase voltage (99 kV) AND the current flow on 220 kV lines exceeds 1000 A, all 220 kV line CB’s would trip with a time delay of 200 msec.

However, in the instant case, due to the time lag in the simultaneous fulfillment of the above voltage and current conditions, SPS operated with a time delay of 500 msec and tripped the two Lingapur bound 220 KV lines.

The 400 kV Bus Coupler tripped on Over load with a time delay of 500 msec.

Munirabad

Lingapur

LA failed

Steel Plant

2

1

SPS trip:

78% V & > 1000 A

4

3

2 5

6

1

BTPS

Guttur

300 MW

130 MW

130 MW

1

b/u trip

ICT

400 kV 220 kV

over speed

2

2

3

4

5

aux. trip

JSWEL

Z-2 sense

O/L trip

ANNEXURE-II



The two 400/ 220 kV ICT tripped on back-up protection with a time delay of 900 msec.

On account of this, Units 3 & 5 & 1 tripped on Over Speed due to lack of availability of the lines for power evacuation.

After half-an-hour or so, the Unit-4 also got tripped due to problem in its instrument air compressor.

Auxiliaries are fed from 220 kV side.

The Unit-6 did not trip during the incident.

400 kV Bus coupler settings: 149% of ICT current for 0.5 sec.; 130% for 5 sec; 120% for 10 sec.

Suggested for OR-ing of the conditions in the existing SPS to avoid delayed operation.

SRLDC:

As the OR-ing of the voltage and current conditions in the SPS could lead to frequent trippings, better not to meddle with the existing SPS. Instead, DEF feature in the numerical relay for the 220 kV Jindal – Lingapur lines at Jindal end should be enabled as suggested by KPTCL.

Recommendations: JSWEL to enable DEF feature in the numerical relay for the 220 kV Jindal – Lingapur lines

at Jindal end.


Munirabad

08-03-2015

19:41hrs

ICT -I got tripped on operation of

220KV E/F

Deliberations:

B-Phase LA flashover occurred at Lingapur end on Lingapur – Munirabad-PG 220 kV line-2

As a result, Distance protection at Lingapur end cleared the fault in zone-1. Fault was being fed from Munirabad (PG end) of Lingapur line-2 as the distance relay

sensed the fault in zone-3. ICT-1 at Munirabad-PG tripped on 220 kV DEF protection. As the Kalyani feeder is being fed radially (10-20 MW load), Munirabad-PG – Kalyani

220 kV S/C line tripped on operation of distance protection at Munirabad-PG end.

2

1

Munirabad

Lingapur

Jindal

LA failed

Kalyani Steel

1

2

Distance

protn.

DEF

Z-1 trip

SPS trip

Z-3 trip 220 kV

400 kV

ANNEXURE-II



Unit-3 & Unit-5 at JSWEL also tripped due to SPS operation. SRLDC:

Reason for sensing the fault in Zone-3 at 220kV Munirabad (PG end) of Lingapur line-2.

Both ICT’s at Munirabad-PG would have sensed the fault. However ICT-1 only tripped.

PGCIL (SR-I):

There was mal-operation of distance relay; OEM has been approached.

Kalyani feeder is being maintained by PGCIL.

Recommendations: PGCIL (SR-II) to furnish the reasons for mal-operation of distance relay & non-operation of

220 kV DEF for ICT-2 at Munirabad-PG, along with the remedial measures taken to PCSC forum.

18 Multiple tripping at

Raichur thermal

power station of

KPCL

09-03-2015 at

06:36 hrs

400kV Raichur TPS-Raichur(PG) line-

1&2, 400kV Raichur-Mahboobnagar,

Unit#7 and ICT-2 at RTPS tripped

during the incident. B phase to earth

fault had occurred in 400kV Raichur

TPS-Raichur line-1

GI-2

Deliberations:

As per PMU plots, there occurred two faults on 440 kV RTPS – Raichur-PG line 1.

The first fault occurred at 06:36:18.520 hrs (B-ph to earth fault) and got cleared in 120ms. The second fault occurred 13 sec after the occurrence of first fault involving R, Y & B -phase at 6:36:31.480 hrs, and got cleared in 360 ms

As per TR of Raichur (PG), during the first fault A/R operated successfully.

During the second fault, there was no A/R attempt, and 3-ph trip was given (Fault Current-15KA). Reason for this was stated to be decapping of insulators at RTPS end. Due to this, The 400 kV RTPS – Raichur(PG) line 1 tripped at RTPS end in Zone-1 with SOTF.

RTPS

1

Raichur(PG)

3-ph trip

2

Veltoor (Mehabubnagar)

Z-2 trip

(SOTF) Z-4 start

G7

Distance

protection

(Bn) REF of GT

trip: 6:36:31 hrs

restore: 8:02 hrs

trip: 6:36:23 hrs

restore: 8:18 hrs

trip: 6:36:18 hrs

restore: 8:18 hrs

trip: 6:36:31 hrs

trip: 6:36:36 hrs

restore: 8:02 hrs

RTPS

1

Raichur(PG)

Z-1 trip

(SOTF)

A/R

2

Veltoor (Mehabubnagar)

G7

ANNEXURE-II



The 400 kV Raichur – Raichur(PG) line 2 tripped at RTPS end in Zone-2 with SOTF; no trip at Raichur(PG) end and only Zone-4 start was there.

U-7 tripped on GT Restricted Earth Fault at RTPS. RTPS-Mehboobnagar (Veltoor) 400 kV S/C line tripped at Veltoor end due to

suspected mal-operation of distance protection.

Now POR distance protection scheme is in place at both ends (RTPS and Raichur(PG)) after PSAG meeting at Raichur.

KPCL informed that ICT#2 did not trip during the incident. Observations:

DR/TR of Mehbubnagar (Veltoor) have not been furnished to ascertain the cause of tripping at Mehabubnagar.

Time synchronization of D.R’s at both RTPS and Raichur(PG) with GPS for 400kV RTPS – Raichur(PG) lines – 1& 2 needs to be checked, as there seemed to be a time difference of 5 sec. between PMU plots and the DR’s at both ends.

PGCIL:

With RTPS settings with CB’s in OPEN condition, a simulation was done in the lab for testing the functionality of distance relays and found them to be operating SOTF. To confirm this, it has been planned to test the breakers by availing shutdown of the lines on 28.03.2015.

SRLDC:

After tripping, the problem should have been rectified on that very day itself by taking shut down if required. SRLDC object (oppose) this type of operation.

For short lines such as RTPS – Raichur (PG) 400 kV D/C line, Kurnool – Kurnool(PG) 400 kV D/C line, Optic Fibre based line differential protection could be used.

Recommendations:

KPCL to review REF setting (DMT or IDMTL) for unit-7 by first week of April, 2015 and inform the same to PCSC forum.

TSTRANSCO to furnish Mehaboobnagar’s DR and EL and the reasons for distance relay operation at their end within a week’s time.

PGCIL (SR-I) to rectify the issues relating to A/R operation, relay reach (Z2), reverse reach (Z4) and SOTF auxiliary contacts within a week’s time, and submit the actions taken to PCSC forum.


Kaiga-Kodassalli

line, Unit-1, 2&3 at

Kaiga PowerStation

11-03-2015 at

21:59 hrs

B-phase CT failed in 220kV Kaiga-

Kodasalli line. Bus bar protection of

220kV Bus-2 got operated

GI-1

SLD: Kaiga-1, 2, 3, 4

ANNEXURE-II



Deliberations:

B-ph CT (Current Transformer) failed at Kaiga on Kaiga – Kodasalli S/C 220 kV line. Due

to this,

Kaiga-Kodasalli line tripped on zone-1 distance protection at Koadalli end only. The fault distance recorded at Kaiga end was 203.1 meter in the numerical relay. At 220kV Kaiga switchyard, Main Bus- II differential protection operated tripping Units

1, 2 & 3. KGS:

The Kaiga Generating Station 220 kV switchyard consists of two 220 kV power evacuation lines and two 220 kV Buses Bus-I and Bus-II and the Bus coupler is kept closed. The 400 kV switchyard has four 400 kV power evacuation lines and two 400 kV buses. The 220 and 400 kV buses are interconnected through two ICTs, ICT-1 and ICT-2.

On 11.03.2015, KGS-1 & 2 were operating at 100% FP. 220kV Buses I & II were in service. 220 kV line-I, ICT-2, GT-2, SUT-I and SUT-4 were connected to Main Bus-I and 220 kV line-2, ICT-I, GT-I, SUT-2 and SUT-3 were connected to Main Bus-II. The Bus coupler was in closed condition.

At 21:59: 15 hrs, the B phase CT (current transformer) of 220 kV line 2 (Kaiga-Kodasalli) connected to Main Bus-II failed and caused 220 kV Bus-II Bus bar differential protection to actuate. This resulted in tripping of all breakers connected to 220 kV Bus II including Bus coupler breaker.

Narendra2

Busbar

differential trip

Kadra

G2

ICT2 GT2

SUT1 SUT4

Kodasalli

G1

ICT1 GT1

SUT2 SUT3

B/C

220 kV Bus-I 220 kV Bus-II

Z-1 trip

CT

failure

GT3

G4

Guttur2

Bus-I

Narendra1

G3

GT4 Guttur1

400 kV

Bus-II

Bus Reactor

KGS-2 trip on

process

parameter

KGS-3 trip on

process parameter

due to SUT3 trip

KGS-1 on house

load operation

ANNEXURE-II



Upon tripping of GT breaker of KGS-1 , the Unit survived on house load with half of the station loads being fed from UAT and the other half from SUT-1. Later GT-1 was synchronized back to the grid with 220 kV Bus-I at 23: 19 hrs of 11.03.15.

In KGS-2, the 6.6 kV auto transfer took place as per design. But during the transient due to the voltage dip in the station aux. 6.6 kV Bus, some of the auxiliary loads tripped leading to reactor trip on process parameter as per design.

In KGS-3, SUT-3 tripped on 220 kV bus-II differential protection actuation and Auto Transfer got blocked due to excessive voltage dip on station auxiliary 6.6 kV buses as the fault location was very nearby. This caused tripping of some of station auxiliary loads on bus under voltage leading to reactor trip on process parameter as per design.

In both the cases, 6.6 kV voltage came down to 1 kV and the current drawal went up to 7 times which resulted in tripping of the auxiliaries instantaneously.

Remedial measures: The failed CT of Kaiga - Kodasalli 220 kV line was replaced with new CT and line has

been taken back into service at 18:14 hrs of 15.03.15. The reason for CT failure is being investigated. Lines are in service since 1993; CTs and CVTs have been planned to be replaced.

SRLDC:

The fact that a 100 msec. fault could not have been sustained by the auxiliaries calls for changing their settings.

Recommendations: KGS to furnish the reasons for CT failure to PCSC forum.

20 Tripping of ICT-2

at Mahboobnagar

09-03-2015 at

7:57 hrs

Tripped on operation of restricted earth

fault (REF) relay while charging 400kV

Raichur-Veltoor feeder

GI-1

Deliberations:

SRLDC:

As per FIR, ICT-2 tripped on operation of REF protection while charging 400kV RTPS -Mehboobnagar line. However, no fault was observed from synchrophasor data.

The station shall be kept under observation. TSTRANSCO:

Moisture ingressed into the neutral CT compartment and REF got activated.

ICT-2 is using 7 CTs (HV, LV and neutral) for REF protection; REF relay setting is 0.2 A Remedial measures:

The accumulated water in terminal box of the Neutral CT drained out and made

vermin and water proof.

SRPC:

No DR/TR furnished, which may be uploaded/ furnished.

ANNEXURE-II



21 Tripping of 400

kV Dichipally –

Ramagundam and

Unit-6 at

Ramagundam

09-03-2015 at

00:56 hrs

Line tripped on B phase to earth fault.

Unit-6 tripped on operation of GT

differential protection

GI-2

Deliberations:

NTPC: Tripping of Dichipally-Ramagundam STPS 400 kV S/C line:

This line tripped on B phase to Earth fault on zone 1 at RSTS end and Zone-2 at Dichipally end.

The fault current was observed to be apprx. 30 kilo amp and fault distance of 34. 5 kilo metres from Ramagundam.

A/R is not active on this line.

Remedial measures: Line patrolling was done by TSTRANSCO. No visible fault observed. Line taken into

service. Tripping of Unit – 6 at RSTPS:

Unit-6 tripped on GT differential protection despite no fault in the GT.

The cause could be due to non-enabling of zero sequence compensation (ZSC) feature in the numerical relay, which could mal-operate the unit protection for through fault.

Remedial measures: ZSC was enabled in the relay meant for protecting Unit-6 (REG -670)

Recommendations:

NTPC, Ramagundam to enable A/R feature on Dichipally – RSTPS 400 kV S/C line in coordination with TSTRANSCO.

NTPC to enable ZSC feature in relays meant for protecting the other generating units.

22 Tripping of

HVDC pole-1&2

at Gazuwaka and

400kV 400kV

Jeypore Gajuwaka

line -1

14-03-2015 at

17:12 hrs

HVDC Pole-1 at Gazuwaka tripped due to

tripping of filter banks and Pole-2 tripped

due to operation of differential protection.

400kV Jeypore-Gazuwaka line-1 tripped

on over-voltage from Gazuwaka end.

GI-2

ANNEXURE-II



Deliberations:

As per FIR of HVDC, Gazuwaka, R-phase to earth fault (Distance from Gajuwaka - 146.6 KM;

From Jeypore end 43.5 KM) had occurred at 17:12:33 hrs in 400kV Jeypore-Gazuwaka line-2. During a single phase fault, at Jeypore end there is provision for single phase auto reclose and at Gajuwaka there is provision for 3 phase auto reclose. The line successfully auto reclosed from both the ends.

Some 750ms after the fault in 400kV Jeypore-Gazuwaka line-2, L.A failure occurred in East side filter banks at Gakuwaka and this led to operation of instantaneous over current relay and tripping of East side filter banks. The tripping of Filter banks led to blocking of Pole-1 at Gazuwaka.

800ms after occurrence of fault in line-2, 400kV Jeypore-Gazuwaka line-1 tripped on operation of Over voltage, Stage II protection at Gazuwaka end (i.e. during auto reclose period of Line-2). However, line-1 did not trip from Jeypore end as direct trip was not received there.

Pole-2 at Gazuwaka tripped on operation of Converter Transformer differential current B-phase trip.

After tripping of HVDC pole-1&2, 400kV Jeypore-Gazuwaka Line-1 was holding from Jeypore end and in tripped condition at Gazuwaka end. Breakers of 400kV Jeypore-Gazuwaka Line-2 was in closed condition from both ends. Line-1 was hand tripped from Jeypore end to reduce the over voltage condition.

East Bus

P1

East

Filters

P2

P2

Filters

South

Filters

400 kV

AC S/S

Jeypore

2 1

South Bus

Pole-2 trip:

converter trf. diff.

protn. Line-1 trip:

O/V stg-2

East filters trip:

inst. O/C protn.

due to LA failure

Pole-1 block:

due to

non-availability

of filter bus

1 2 3

4

Gajuwaka HVDC B2B

ANNEXURE-II



PGCIL (SR-I):

Remedial measures: o PLCC is not working properly. PLCC panels are being retrofitted with ETL. LOA

already placed, and the work may get completed in 3 months. o Pole-2 tripping due to differential protection operation has been referred to

OEM (M/s ABB).

SRLDC:

If PLCC is not working, the line should not be kept into service in the first place.

Recently, ILFS-NLC 1 Exp. line was also charged without PLCC.

Any problem on PLCC is to be reported to SRLDC.

Over voltage observed in D.R of Jeypore – Gajuwaka line 1 is less than Stage-1 setting.

DR-EL time sync. to be checked at Gajuwaka.

Recommendations: PGCIL (SR-I) to furnish the reasons for Converter Transformer differential protection

operation for Pole-2 along with the remedial measures taken.

23 Tripping of HVDC

Bhadravathi Pole-1

18-03-2015 at

13:55 hrs

Pole tripped due to failure of auxiliary

supply

GI-2

Deliberations: As per TR of HVDC, Bhadrawati:

On 18.03.2015, the auxiliary supply of both pole-1 & 2 was being fed by 33KV WARORA feeder as MIDC feeder was already out.

At 13:53Hrs, WARORA Aux Supply tripped, due to which main pumps of VCC1 & VCC2 started running at half-speed.

DG-1 & 2 came into service.

Now the auxiliary supply of both pole-1 & 2 were being fed by DG-1 & DG-2 and both the pumps of VCC1 & VCC2 were to run at full-speed now.

However, the main pump of VCC1, Pump-1, which was at half-speed before DG came into service did not attain full speed and Pole-1 tripped on “VCC1.MAIN CIRCUIT FULL FLOW - V-LOW” alarm.

The control circuit of VCC1 Main pump has been checked for not attaining full speed. The control circuitry was found OKAY. No abnormality observed in the control circuit. This leads to assumption of malicious operations of Pump-1 which needs further investigation during Pole Shut down.

It is observed that the disturbance/frequent tripping in the Auxiliary power supply caused the mal-operation of control logic circuit (Memory logic) of valve cooling system which resulted in failure/stopping of Main pump and tripping of the pole consequently.

The 33kV aux supply taken from MSEDCL is unreliable and not stable. Several trippings have occurred due to disturbance in aux supply and the problem is persisting.

It is expected that such disturbances may get avoided once the 315 MVA,400/220/33 kV,3Phase ICT gets loaded. The ICT has been ideally charged on 17.03.2015 and would be loaded once clearance from MSETCL is obtained.

SRPC:

PGICL (SR-I) has not yet submitted the compliance report on PSAG-11 recommendations. SRLDC:

ANNEXURE-II



MS (SRPC) to MS (WRPC) letter could be written for expediting the aux. power supply problem issue.

Recommendations:

PGCIL (SR-I) to submit the compliance report on PSAG-11 recommendations to PCSC forum.

24 400 kV NCTPS II-

VALLUR 1

21-Mar-15 at

23.33 hrs.

Tripped while opening 400kV

VLR-NCTP 2 on broken

conductor protection

GI-2

25 400 kV NCTPS II-

VALLUR 1

20-Mar-15 at

13.02 hrs.

DISTANCE PROTECTION GI-2

26 400 kV NCTPS II -

VALLUR 2

19-Mar-15 at

19.40 hrs.

Tripped on operation of broken

conductor alarm at NCTPS

GI-2

Deliberations:

On all the three occasions, the 400 kV NCTPS – NTECL (Vallur) lines 1/ 2 tripped due to broken conductor protection at NCTPS, Stage II end; NTECL (Vallur) end tripped due to receipt of DT from NCTPS, Stage II.

NTECL, Vallur:

Heavy load/current unbalance has been observed in Vallur- NCTPS line 1 and 2 which has led to tripping of lines on Broken conductor protection many times from NCTPS end and once from Vallur end.

TANTRANSCO may analyze the reason for the unbalance in the lines and take necessary corrective action.

TANTRANSCO:

As part of remedial measures, broken conductor protection trip has been disabled at NCTPS –II.

At NCTPS the line protection setup is: o Main-1: line differential (Micomp); Main-2: line differential (RAD). o Different pairs of fibres are used for Main-1 & 2 relays. o Distance protection is used as back up protection. o Back up O/C and E/F are also there.

KPTCL:

220 kV cables in Bangalore are also using line differential protection.

PGCIL (SR-II):

400 kV trip is disabled for broken conductor in SR-2 and only alarm is enabled.

ANNEXURE-II



27 400 kV NCTPS II- VALLUR 1 17-Mar-15 at

03.00 hrs.

Y-N FAULT GI-2

Deliberations: Line tripped on Y phase differential protection @ 3:00hrs. due to tracking of insulators on

TANTRANSCO tower at NTECL.

TANTRANSCO:

Distance between NTECL and NCTPS is 3.35 km; the lines have been cleaned; 6 towers have been scanned from Vallur end; hot line washing has also been done.

28 400 kV NCTPS II - VALLUR 1 11-Mar-15 at

17.03 hrs.

TRIPPED WHILE CHECKING BUS

BAR DIFFERETIAL PROTECTION

GI-2

Deliberations:

Line tripped at NTECL on R phase differential protection @ 17:03 hrs during testing of bus-bar protection relay; line was holding at NCTPS-II end. NTECL, Vallur:

As part of remedial measure, an unwanted logic in line protection relay, which caused the tripping

while testing bus-bar protection relay, was removed.

29 Tripping of 220kV Neyveli-

Villanur

18-03-2015 at

11:57 hrs

R-N fault in Line. Fault observed

for 400ms in Neyveli end D.R

GI-1

Deliberations:

As per TR of Villianur: R-Phase earth fault occurred on the 230KV Neyveli-Villianur line; MICOM P442 Main-I Numerical Distance Protection relay gave A/R single shot closing pulse and closed the tripped R-phase pole column of the 230KV Neyveli Breaker at Villianur Auto Sub-Station end. However, owing to persisting fault, the breaker tripped on receipt of 3-phase trip signal from the distance relay. As per DR of NLC 2: The R-N fault was lasting upto 400 msec only from the time the first shot of A/R operated. (This means the fault got cleared in the A/R open dead time of 1 sec.) Remedial Measures taken at Villianur by PED:

Panel replacement has been done. SRPC:

Reasons for above discrepancy may be analysed by Villanur.

DR not uploaded by Villianur.

FIR uploaded by NLC 2 was not in order; TR not uploaded.

ANNEXURE-II



III Tripping events due to PLCC Mal-operation:

Sl. No.

Element Date & Time

Reason PCSC Deliberations

1 Tripping of 400kV

Ghanapur -

Mamidapalli line

18-02-2015

at 12:12 hrs Line tripped from

Mamidapalli end due

to direct trip receive

from Ghanapur

PGCIL: even as on today the

alarm is persisting.

SRLDC: The line is not to be

charged under non-cleared

alarm condition.

2 Tripping of 400 kV

Khammam-Kalpakka

line-1

18-02-2015

at 12:58 hrs Line tripped at

Kalpakka end only due

to direct trip receive

and was holding from

Khammam

PGCIL (SR-I): There was a

problem with Main-1 relay. It was

reset, and found to be working

normally.

3 Tripping of 400kV

Malkaram-

Hyderabad line

20-02-2015


Malkaram end only

due to direct trip

receive and was

holding from

Hyderabad end.

PGCIL (SR-I): At Ghanapur

(Hyderabad), due to NTMC works

in progress, a spurious signal got

extended as DT to Malkaram.

4 Tripping of 400kV

Munirabad-Guttur

line

21-02-2015


Munirabad

(Guddadalli ) end only

due to direct trip

receive and was

holding from Guttur.

End to end testing has to be carried

out.

5 Tripping of 400kV

Hiryur-Neelamangala

line-2

27-02-2015


Neelamangala end

only and was holding

from Hiryur.

End to end test has already been

carried out.

6 Tripping of 400kV

NLC EXP-IL&FS

line

28-02-2015

at 19:17 hrs Line tripped from

NLC –I expansion end

only due to direct trip

receive and line was

holding from IL&FS.

The faulty card has been replaced

at IL&FS; Tested at NLC end

also.

7 Tripping of 400kV

Narendra-Guttur 11-03-2015


Narendra end only due

to DT receive.

Narendra-Davanagere line -1

tripped at Narendra end only, and

was holding from Guttur

(Davangere) end.

End to end testing has to be

done.

8 400 kV Tiruvelam -

Kalivandapatu 1 11-03-2015


kalivaldapattu end

only due to DT

receive.

Line tripped due to mal-operation

of DTPC (Digital tele-protection

coupler) at Kalvindapattu end only.

The line was holding from

ANNEXURE-II



Tiruvalam end.

9 Tripping of 400kV

Thiruvelam-

Kalivandapattu line-1

17-03-2015


Kalivandapattu end

only

Line tripped at Kalvindapattu end

only, and was holding from

Tiruvalam end.

For all the above cases of PLCC mal-operation, the following shall be carried out by the concerned

Constituents in co-ordination: Healthiness of PLCC system components (hardware and software) at both ends shall be checked

and faulty components shall be repaired/replaced. End-to-end communication for DT/ permissive & other signals may be ensured by testing at both

the ends.

IV. Tripping events due to failure/ non-operation of Auto-Reclose (A/R) during

Transient fault:

S.No Element Date &

Time Reason PCSC Deliberations

1 Tripping of 400kV

NTPL-Tuticorin P.S

line

23-02-2015

at 4:42 hrs

and

24-02-2015

at 4:30 hrs

Transient fault in

B-phase and line

auto-reclosed from

Tuticorin P.S end.

Line failed to

reclose from NTPL

end

On both the occasions, line auto-

reclosed from Tuticorin Pooling

Station end, but failed at NTPL

end.

A/R setting at NTPL end has

been revised to 1 sec.

PGCIL (SR-II): 1. Line inspection was under

progress. 2. Tower No 29 from NTPL end

B-Phase toward s NTPL end PLR

insulator was replaced by CLR

insulators by PGCIL and R & B

Phase insulators were cleaned. SRPC: A/R scheme shall be tested

at NTPL in coordination with

Tuticorin PS.

2 Tripping of 400kV

Jeypore-Gazuwaka

line-1

28-02-2015

at 00:19 hrs R-phase to earth

fault had occurred

in line. Line auto

reclosed at Jeypore

end and failed to

reclose at

Gazuwaka.

Line auto reclosed at Jeypore end

and failed to reclose at Gazuwaka.

Relay testing is to be done.

SRPC: Remedial measures taken

may be furnished by PGCIL (SR-I)

to PCSC forum.

ANNEXURE-II



3 Tripping of 400kV

Coastal-NTPL line

02-03-2015

at 3:51 hrs

Line tripped on a

B-phase to earth

fault. Line auto-

reclosed from

coastal end and

tripped at NTPL

end.

A/R setting at NTPL end has

been revised to 1 sec.

SRPC: A/R scheme shall be tested

at NTPL in coordination with

CEPL.

4 Tripping of 220kV

Ambewadi-Ponda

line-1

11-03-2015

at 11:10

Line did not auto

reclose

SRPC: A/R scheme to be enabled

for this inter-state line.

5 Tripping of 220kV

Ambewadi-Ponda

line-2

11-03-2015

at 13:32

Line did not auto

reclose



6 Tripping of 220kV

Yerandahalli-Hosur

line

18-03-2015

at 13:12 hrs

B-N fault. Line did

not auto-reclose



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

ANNEXURE-II

Meeting

No /

Index

Details

of Event

Date Reason PCSC Recommendations Utility

Responsibl

e for

Status of Recommendations

as on 16.04.2015

Remarks

39/III/1 Tripping

of 400kv

VTPS-

Satenapal

li line-

1 &2

10, 11, 13,

14,15 Dec

2014

voltage.

grading in over voltage protection

needs to be verified.

PCSC forum recommended APTRANSCO to check up the

drop off to pick up ratio of the Overvoltage relay and correct

it (if needed).

APTRANS

CO/

APGENCO

APTRANSCO informed vide their e-mail

dated 27.02.15 that the issue pertains to

APGENCO.

Pending

40/IV/2 400 kV

HYDER

ABAD -

KURNO

OL line

07-01-2015

at 6:17 hrs

Line tripped on Rphase to earth fault.

A/R lock out

observed in E.L of Hyderabad end

APTRANSCO was requested to check up the A/R feature at

both the ends and submit the remedial measures to the PCSC

forum.

APTRANS

CO

Yet to be informed Pending

41/II/2 Tripping

of 400kV

Srisailam-

Mamidap

alli-2 line

and

400kV

Srisailam-

Satenapal

li-1 line

23-01-2015

at 16:10 hrs

Bus-2 at Srisailam became dead while

converting Srisailam generator to

condenser mode. Direct trip was

received at Mamidapalli and

Satenapalli end.

furnish the reasons for BBP operation at

Srisailam LLB and the remedial action taken to PCSC forum.

TSGENCO Yet to be informed Pending

Pending Implementation of PCSC Recommendations (30th to 41st)

Andhra Pradesh

Telangana

Karnataka

ANNEXURE-III

1 PCSC-42

30/I/A RTPS

Tripping

incidents

and the

Spl

meeting

held at

RTPS on

13th and

14th

March

2014

Mar-14 Spl meeting held at RTPS on 13th and

14th

March 2014

The PCSC forum recommended for replacement of existing

electromechanical relays with Numerical relays.

KPCL 1. e- Tender folated for the retrofit of

existing static relays with Numerical version

for lines M.nagar,M.bad,ICT-1 & 2 -

Technical Bid opened & price bid yet to be

opened.

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

with numerical version -Budgetetory offers

obtained and is under process.

3. Order placed on M/s Siemens to replace

relays. The work will be Completed by May

- 2015.

Pending

33/II/3 400kV

Hiriyur-

BTPS

line-2

22-05-14 &

23/05/2014

B phase to ground fault had occurred in

line and line auto reclosed at Hiriyur

end but failed to reclose at BTPS end.

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

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

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

2. Shtu down of lines availed to commission

the auto reclosing schme fro 400 kV line at

BTPS.

3. A/R shall be enabled in next shutdown

Pending

34/III/1 400kV

Raichur-

BTPS

line

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

Line did not auto reclose

A/R at BTPS end to be made operational within one month KPCL 1. A/R for 220kV lines enabled already.

2. Shut down of lines availed to commission

the auto reclosing schme fro 400 kV line at

BTPS.

3. A/R shall be enabled in next shutdown

Pending

38/GD/3

.5

GD-1 at

Kadra

and

Kodasalli

hydro

power

station

13-11-2014

at 19:31hrs

A fault had occurred in 220 kV Kadra

and

Kodasalli. As A result, de-energization

of

220kV bus occurred at Kadra and

Kodasalli.

1. The PCSC forum requested KPCL to speed up the

installation of Numerical Distance Protection relay in Kadra

–Kaiga and Kodasalli –Kaiga.

2. The PCSC forum requested KPCL to submit the

implementation status of PSAG-10 recommendations within a

week’s time.

KPCL All the recommendations of PSAG - 10 are

completed except the following pending

issue:

i)e-NIT floated on 28.07.2014 for

procurement of Numerical distance relays &

GPS. Bid evaluation is under progress. The

work will be completed by December -

2015. Hower, as per the recommendations

of PSAG, Relays were temporarily

rearranged, replaced and wired up. testing &

commissioning shall be completed with the

assistance of KPTCL by March 1st week ,

2015.

Pending

ANNEXURE-III

2 PCSC-42

34/I/6 400/220

kV ICT-1

& 2 at

MUNIR

ABAD

16-07-2014 As reported directional over current

relay of ICT’s operated due to

snapping of line jumper in 220kV

Lingapur line.

1. Bus bar protection shall be provided by asset owner ( i.e

KPTCL) .

2. Settings for main distance protection & Overcurrent

protection shall be examined and reviewed.

3. Time synchronization of the Substation shall be ensured.

4. Correct DR shall be submitted to the SRLDC for trip analysis.

KPTCL Management approval is obtained for taking

up the work of providing bus bar protection

to 220kV buses at Guddadahally

(Munirabad) Sub Station along with

replacement of 3 core/age old CTs of 220kV

bays belong to KPTCL.

Under implementation

Mail recieved on 25-03-2015 (KPTCL):

1. KPTCL has taken action to provide bus

bar protection to 220kV buses.

2. Over current relay Settings of ICTs to be

reviewed by PGCIL.

Pending

38/GD/3

.1

GD-1 at

Mahaling

apura

Substatio

n of

KPTCL

25-10-2014 Fault had occurred in 220kV

Mahalingapura-Narendra line-2. Due to

the

failure of relay operation at

Mahalingapura,

breakers at remote end tripped which

resulted in bus dead condition.

1. PCSC forum recommended KPTCL to replace the old static

distance protection relays with numerical relays.

2. PCSC forum also requested KPTCL to provide a broken

conductor alarm indication in Control Room.

3. Standing instruction needed to be given to the all substation

personnel for not changing the relay settings without approval of

RT/MRT wing.

KPTCL Mail received on 25-03-2015 (KPTCL):

1.Existing Back up relays will be replaced

by numerical type distance

relays.Procurement is in tendering stage.

2. Alarm for Broken conductor is in service.

3. Clear instructions have been given to

station staff.

Pending

38/GD/3

.2

GD-1 at

Guttur

Substatio

n of

KPTCL

05-11-2014

at 11:42 hrs

Circuit breaker of 400kV Guttur-

Hiriyur

line-1 failed at Guttur end while

availing

shutdown for replacement of CVT. The

failure of breaker caused bus fault at

Guttur.

KPTCL was requested to expedite the early implementation of

pending recommendations of:

1. Protection Audit (Phase-I & Phase-II)

2. PSAG-4, PSAG-5, and PSAG-8


Replacement of failed breaker of Hiriyur-1

line, 400kV BC and TBC is taken up at

Guttur. Work is entrusted to M/s

Alstom.Complaince will be furnished to

SRPC upon completion of these works.

Pending

ANNEXURE-III

3 PCSC-42

39/I/5 Tripping

of

400/220k

V

ICT-2 at

Hoody

substatio

n of

KPTCL

01-12-2014 Suspected mal-operation of 220kV side

Rphase

over current relay

1. PCSC forum recommended KPTCL to replace the relay with

a different make.

2. KPTCL was also requested to train the O&M personnel

adequately before performing any maintenance works to avoid

such unwanted trippings.


C&R panels of 500MVA ICT 1&2 will be

replaced under scheduled R&M works.

O&M personnel are instructed to take

sufficient care in order to avoid unwarrented

trippings.

Pending

40/I/1 GD-1 at

220kV

Ambewa

di Station

of

KPTCL

22-12-2014

at 21:22 hrs

Triggering incident was B-phase to

earth fault in 220kV Ambewadi-

Nagzari line-1. B-pole of breaker did

not open at Ambewadi end. LBB

protection not available at Ambewadi

end. All elements tripped on Zone-2

from remote ends.

1. Till the completion of R&M works for bus bar and LBB

protection, KPTCL shall explore the possibility of having split

bus operation at Ambewadi and submit the details of the same

to PCSC forum.

2. KPTCL shall check up the ICTs protection system for

finding the cause of not tripping for the line fault (through fault)

and submit the remedial measures.

3. KPTCL shall provide the details of the tripping of Supa hydro

station connected downstream from 110 kV bus.

KPTCL Yet to be informed Pending

40/IV/1 220kV

Sedam-

Tandur

line

20-12-2014

at 22:20 hrs

Line tripped on Yphase to earth fault

from both the ends

KPTCL was requested to explore the possibility of providing

A/R feature to this line and submit the remedial measures to the

PCSC forum.


41/I/1 GD-1 at

220kV

Kadra

power

Station of

KPCL

16-02-2015

at 12:56 hrs

Triggering incident was B-phase to

earth fault had occurred in 220kV

Kadra-Kodasalli line. Line tripped from

Kodasalli end only. 220kV Kaiga-

Kadra tripped in Zone-3 from Kaiga

end. Tripping of evacuating lines

caused bus shut down at Kadra hydro

station.

1. KPCL to make functional the Main2 (EPAC) relay with

the help of KPTCL at the earliest.

2. KPCL to investigate the reason for DC fuse fail during

transient fault in 220kV Kadra-Kodasalli line including the

testing/ checking of DC supply cables, breaker control cables,

and trip coils.

3. KPCL to ensure supply for Main-1& Main-2 protections,

Trip Coils (TC1, TC2) from separate battery banks.

KPCL Yet to be informed Pending

ANNEXURE-III

4 PCSC-42

41/I/3 Complete

outage of

Nagjheri

Hydro

power

station of

KPCL

(GD-1)

22-02-2015

at 11:09 hrs

During de-synchronization of Unit-3,

the Y-pole of the CB did not open (was

locked-out). This caused LBB

protection to operate resulting in

tripping of the Bus and all connected

220kV lines and running units at

Nagjheri power station.

1. KPCL to investigate the cause of Y-pole breaker lock-out of

Unit-3, and take suitable remedial measures within a week’s time

2. KPCL to furnish what caused LBB initiation and furnish

LBB Scheme details to PCSC forum

3. KPCL to furnish detailed tripping report (with DR & EL)

of the incident


41/I/4 Complete

outage at

220kV

Sedam

Substatio

n of

KPTCL

(GD-1)

27-01-2015

at 8.00 hrs

R-Phase to ground fault occurred on

220kV Sedam-Shahpur line. Fault not

cleared from Sedam end due to stuck-

breaker condition. While the Sedam-

Sahapur line tripped from Shahapur

end in Zone-1, the other 220 kv lines

from Sedam tripped at remote ends in

Zone-2. This caused complete outage

of 220kV Sedam substation.

1. KPTCL to provide Bus bar and LBB protections for 220

kV bus at Sedam S/s.

2. KPTCL to implement A/R feature on 220 kV Sedam-

Tandur inter-state line.


41/II/11 Tripping

of 400kV

BTPS -

Hiriyur

line-2

13-02-2015

at 17:07hrs

Line tripped at BTPS end only. furnish remedial measures taken to prevent

recurrence of PLCC mal-operation at BTPS.


36/II/9 400kV

Arasur-

Mettur

Line I

29-09-2014 Mettur S/s to Enable A/R Scheme. TANTRA

NSCO

1. During the 38th PCSC meeting,

TANTRANSCO informed that the Auto

Reclosing facility would be enabled within

15 days.

2 A/R scheme will be implemented after the

commissioning of 400 kV Thiruvalam Line-

I & II.

Pending

Tamil Nadu

ANNEXURE-III

5 PCSC-42

37/II/3 400kV

Mettur-

Arasur

line-1

29-09-2014 Line tripped due to Y-Phase to earth

fault.

Line did not auto reclose as Auto

reclose scheme is kept in non-auto

mode.

A/R scheme to be enabled. TANTRA

NSCO




15 days.

2. A/R scheme will be implemented after

the commissioning of 400 kV Thiruvalam

Line-I & II.

Pending

38/II/3 Tripping

of 400kV

Mettur-

Arasur

line-2

22-10-2014 Line tripped on Rphase

to earth fault.

non-auto mode.

A/R feature to be enabled. TANTRA

NSCO




15 days.

2. A/R scheme will be implemented after

the commissioning of 400 kV Thiruvalam

Line-I & II.

Pending

34/I/3 Tripping

of HVDC

Bhadrav

ati Pole-1

& 2

09-07-2014 As reported, pole-1&2 tripped due to

auxiliary supply failure.

1. The PCSC forum recommended PGCIL, SRTS-I take up the

issue with WRTS to submit the report as per IEGC guidelines.

2. SRLDC is also requested to write a letter to WRLDC to submit

the reports to SR also.

3. Based on the SRTS/SRLDC correspondences, SRPC would

take it up with WR and PGCIL if the issue is not getting resolved.

4. Complete analysis of the faults and rectification/remedial

action taken to avert similar occurrence in the HVDC Back to

Back station shall be submitted.

PGCIL 1. Implementation of Tertiary Winding of

ICT for the auxilliary power supply is going

to come up which resolves this issue.

2. PGCIL informed that all issues would be

discussed during PSAG-11 visit.

Pending

Kerala

PGCIL

ANNEXURE-III

6 PCSC-42

34/I/7 HVDC

BHADR

AVATH

I POLE 2

18-07-2014 As reported pole-2 tripped due on 5th

harmonic alarm.

1. Complete analysis of the faults and rectification/remedial

action taken to avert similar occurrence in the HVDC Back to

Back station shall be submitted.

2. The PCSC forum recommended PGCIL, SRTS-I take up the

issue with WRTS to submit the report as per IEGC guidelines.

3. SRLDC is also requested to send a letter to WRLDC to submit

the reports to SR also.

4. Based on the SRTS/SRLDC correspondences, SRPC would

take it up with WR and PGCIL if the issue is not getting resolved.

PGCIL Yet to be informed Pending

39/I/1 Tripping

of 400kV

Gooty-

Somanah

alli

22-11-2014 Line tripped due to

suspected PLCC

Mal-operation at Gooty

end.

Retrofitting of the relay or installation of Optical Fiber cable is

recommended by PCSC forum to PGCIL.


40/II/1 Tripping

of 400kV

Vijayawa

da-

Gajuwak

a

line

18-12-2014

at

18:33 hrs

Line tripped due to operation of TEED

protection at Gajuwaka end due to

opening of jumper of Y phase CT.

PGCIL shall review the TEED protection at Gajuwaka end

and submit the details to PCSC forum.


41/II/1 Tripping

of 400kV

Vijayawa

da-

Nellore

line 1

22-01-2015

at 11:39 hrs

line tripped on operation of TEED

protection at Vijayawada end and direct

trip was received at Nellore end

review the TEED protection at Vijayawada

end with their OEM group and submit action taken report to

PCSC forum.


ANNEXURE-III

7 PCSC-42

41/II/6 Tripping

of 400kV

Coastal

Energen

(CEPL)---

NTPL

line

07-02-2015

at 01:07 hrs

and at

00:08hrs on

08-02-2015

B-phase to earth fault had occurred in

Line during both instants. As seen from

D.R of Coastal Energen distance relay

sensed fault in zone-2 and earth fault

protection had operated which resulted

in tripping of line.

to carry out hot-line washing regularly as NTPL is

in highly polluted location.


41/II/8 Tripping

of HVDC

Talcher-

Kolar

pole-2

10-02-2015

at 7:37 hrs

Pole-2 tripped due to ESOF from

Talcher end

test the pumps at Talcher HVDC during pole

shut-down and submit the report to PCSC forum.


41/II/16 Tripping

of 400

kV

NEYVE

LI TS 2 -

PUGAL

UR

15-02-2015

at 18:38 hrs

Line tripped at pugalur end due to

direct trip receive

PGCIL to check the protection coupler of PLCC system at

Pugalur end.


41/III/1 Tripping

of 400kV

Gooty-

Somanah

alli line

20-01-2014

at 11:44 hrs

line tripped at Gooty end only and was

holding from Somanahalli end line

• PGCIL to furnish remedial measures taken.

• PGCIL to properly tune PLCC panels.


ANNEXURE-III

8 PCSC-42

41/III/2 Tripping

of 400kV

Udumalp

et-

Palakad

line-1&

400

Udumalp

et-Arasur

line-2

09-02-2015

at 9:50hrs

PLCC of Udumalpet-Arasur-2 mal-

operated

• PGCIL to furnish remedial measures taken.

• PGCIL to properly tune PLCC panels.


37/I/9 Tripping

of

400/220k

V ICT-

1&2 at

UPCL

04-10-2014 ICT-1&2 tripped during transient fault

in R-phase in 400kV Hassan-UPCL

line-1

To avoid tripping of ICTs for line fault, UPCL is requested to

review the settings of ICT’s SEF relay and consider IDMT

setting instead of existing Definite Time setting.

UPCL It has been reported by UPCL that, the work

of review of relay coordination and setings

for the entire plant is given to M//s Alstom

for entire plant. UPCL has furnished the

settings given by M/s Alstom for

verification. Revised settings will be issued

this week for implementation

Pending

40/II/8 Tripping

of Unit-1

at

Kudankul

am

14-01-2014

at

19:20 hrs

Y-phase Differential protection of

Generating transformer of Unit-1 got

operated which resulted in tripping of

Unit-1.

1. NPCIL, Kudankulam was recommended to submit all the

relevant reports of the above incident.

2. PCSC forum also requested NPCIL, Kudankulam to upload all

the reports (DR/EL/ FIR) of any incident in the SRLDC web

portal within 24 hrs of its occurrence.

NPCIL,

Kudankula

m


41/II/10 Tripping

of

Hassan-

UPCL

line-2

12-02-2015

at 15:57 hrs

Line tripped due to high resistance fault

in B-phase. DEF picked up at hassan

end and DT was sent to UPCL. DEF

protection did not pick up at UPCL

revise their DEF relay settings. UPCL Yet to be informed Pending

Others

ANNEXURE-III

9 PCSC-42

41/II/12 Tripping

of

400KV

Coastal-

NTPL

line

13-02-2015

at 22:54 hrs

Line tripped B-phase to earth fault and

later tripped on R-Y phase fault. From

Coastal end D.R, Y & B poles of

breaker opened first and R-pole

appears to be opened on Pole

discrepancy.

check A/R scheme at their end. CEPL Yet to be informed Pending

41/IV/2 400kV

Tuticorin

PS-NTPL

line

09-02-2015

at 03:17 hrs

Y-phase to earth fault had occurred in

line. Line auto reclosed at Tuticorin PS

end and failed to reclose at NTPL end.

NTPL to check A/R scheme at their end. NTPL Yet to be informed Pending

36/II/8 400kV

Raichur-

Muniraba

d line

07-09-2014 B-phase to earth fault had occurred in

line.

Line auto reclosed at Munirabad end

and failed to reclose at Raichur end.

KPTCL:

PD (pole discrepancy) time delay would be changed.

PGCIL /

KPTCL


37/I/6 Tripping

of

400KV

Hassan-

UPCL

line-2

25-09-2014

Back up earth fault protection had

operated at Hassan.

At UPCL end the high resistance fault

got converted into a R ph-B-ph fault

which resulted in operation of distance

protection Zone-1.

The reason for non-picking up of Back

up earth fault at UPCL needs

investigation.

1. At UPCL end, unused zones of distance protection

(probably zone 5 to 8) shall be disabled.

2. At UPCL end, time synchronization between main-1 and

main-2 relays shall be ensured.

3. UPCL shall ensure time synchronization with Hassan

substation.

4. Reasons for non operation of back up protection at UPCL

for high resistance fault is to be submitted.

5. Reasons for not sending DT to UPCL by Hassan end is to

be submitted.

6. Settings of UPCL are to be reviewed and informed to PCSC

UPCL /

KPTCL

It has been reported by UPCL that, the work

of review of relay coordination and setings

for the entire plant is given to M//s Alstom

for entire plant. UPCL has furnished the

settings given by M/s Alstom for

verification. Revised settings will be issued

this week for implementation.

Pending

38/II/2 Tripping

of 400kV

Khamma

m-

Kalpakka

line

11-10-2014 Line tripped on Yphase

to earth fault.

reclose at Khammam

end.

APTRANSCO and TSTRANSCO were requested to clear the

corridor jointly at the earliest.

PGCIL/

APTRANS

CO/

TSTRANS

CO

Yet to be informed. Pending

Miscellaneous

ANNEXURE-III

10 PCSC-42

38/II/5 400kV

Ramagun

dam-

Hyderaba

d line-4

27-10-2014

to earth fault.

reclose at Hyderabad

end due to

PLCCmal-operation.

Planned to replace the PLCC system within a week's time at both

the ends during the shutdown.

NTPC/

PGCIL


39/I/2 Tripping

of

400Kv

Ghanapur-

Mamidip

ally

line

22-12-14

at 10:52 hrs,

24-12-14 at

11:32

hrs,

24-12-14 at

16:16 hrs

Due to PLCC Mal-operation at HYD

S/S end, DT received at MMPLY end

and line got tripped.

PGCIL is requested check up with the manufacturer to resolve

the issue and submit remedial measures to PCSC forum.

PGCIL/

TSTRANS

CO


40/II/3 Tripping

of 400

kV

TALAG

UPPA

–

HASSA

N line

01-01-2015

at

13:38 hrs

On account of R-phase to earth fault,

line

tripped at Hassan end due to operation

of

distance Zone-2 and non-receipt of

carrier. From D.R of Talaguppa end it

is

observed that fault had occurred in

Yphase.

1. PGCIL and KPTCL to ascertain the reason for the phase

discrepancy in the relay operation and take suitable remedial

measures.

2. KPTCL to check the PLCC operation at Talaguppa end and

submit the report to the PCSC forum.

PGCIL/

KPTCL


41/I/2 Complete

outage at

220kV

Bahoor

Substatio

n of

Pondiche

rry (GD-

1)

15-02-2015

at 11:20 hrs

Bus fault occurred in 110kV bus at

230/110kV Bahoor substation due to

failure of Y-phase main bus strain

insulator. 220kV lines connected to

Bahoor (viz., Bahoor- NLC TPS II and

Bahoor – Pondy) tripped from remote

end on operation of back up protection.

1. PED to investigate the cause of non-operation of ICT’s

protection system (differential protection, back-up

protection) and review the relay settings suitably.

2. PGCIL to check the settings of distance relay and back-up

relays for correctness of operation.

PED/PGCI

L


ANNEXURE-III

11 PCSC-42

41/II/3 Tripping

of 400kV

NLC-1

EXP-

IL&FS

line and

400kV

IL&FS -

Trichy

line

24-01-2015

on 13:15 hrs

400kV NLC-1 EXP- IL&FS line

tripped on a R-phase to earth fault.

Line did not auto-reclose. 400kV

IL&FS - Trichy line tripped at Trichy

due to Direct trip receive from IF&FS.

action taken

report on the recommendations given by SRPC Committee in

their meeting held at IL&FS on 19-02-2015 to SRPC.

IL&FS /

PGCIL (SR-

II)/ NLC-1

Exp


41/II/5 Tripping

od 400

kV NLC

EXP-

ILFS line

05-02-2015

at 06:05 hrs

Line tripped due to direct trip receipt

from IL&FS

action taken

report on the recommendations given by SRPC Committee in

their meeting held at IL&FS on 19-02-2015 to SRPC.

IL&FS /

PGCIL (SR-

II)/ NLC-1

Exp


Tripping

of 400kV

NTPL-

Tuticorin

pooling

station

13-02-2015

at 23:12 hrs

Line tripped on R-phase to earth fault

at 22:53 hrs. Line auto reclosed at

Tuticorin pooling end and holding. At

23:12 line tripped on B-phase to earth

fault in zone-2 time.

Tripping

of 400kV

NTPL-

Tuticorin

pooling

station

14-02-2014

at 1:41 hrs

B-phase to earth fault had occurred and

line auto reclosed at 01.09 Hrs and

holding from Tuticorin PS end and line

was and up hand tripping at 01.44.

41/II/13,

41/II/14,

41/II/15

PGCIL to carry out hot-line washing regularly as NTPL is


NTPL to review A/R scheme at their end.

PGCIL/NT

PL


ANNEXURE-III

12 PCSC-42

Tripping

of 400kV

NTPL-

Tuticorin

pooling

station

14-02-2014

at 6:55 hrs

Line tripped on B-phase to earth fault.

Line did not reclose at NTPL end

41/II/13,

41/II/14,

41/II/15

PGCIL to carry out hot-line washing regularly as NTPL is


NTPL to review A/R scheme at their end.

PGCIL/NT

PL


ANNEXURE-III

13 PCSC-42

S.N

o.

Element Name Outage

date/time

Revival

date/time

Reason for Outage Sender/

Receiver

Remedial Measures/ Actions taken

1 400/220 Kv ICT-1

AT SATTENAPLLI

26-02-

2015/

10:19:00

26-02-

2015/

11:30:00

GROUP - A

PROTECTION

OPERATED

TSTRANS

CO

To-be-discussed

2 400 Kv

SATTENAPALLI -

SRISAILAM 2

04-03-

2015/

14:25:00

04-03-

2015/

15:08:00

R-N FAULT TSTRANS

CO/

TSGENCO

To-be-discussed

3 220 kV CHITTOR -

THIRUVALEM

19-03-

2015/

15:18:00

19-03-

2015/

15:46:00

TRIPPED ON R-PH

FAULT

APTRANS

CO/ TNEB

TANTRANSCO: Temporary line

fault.

APTRANSCO:

4 220 kV

AMBEWADI -

PONDA 1

19-03-

2015/

18:55:00

REASON TO BE

STATED LATER

KPTCL To-be-discussed

5 400 kV GOOTY -

NELAMANGALA

19-03-

2015/

14:24:00

19-03-

2015/

14:44:00

TRIPPED B-PH

FAULT

PGCIL

(SR-I)/

KPTCL

To-be-discussed

6 220 kV

AMBEWADI -

PONDA 1

20-03-

2015/

12:40:00

DISTANCE

PROTECTION

RELAY ACTED


Pending Remedial Measures/ Actions taken

for the Critical Tripping Incidents (as on 16.04.2015)

ANNEXURE- IV

1

7 400 kV

TALAGUPPA -

NEELAMANGALA

20-03-

2015/

13:37:00

20-03-

2015/

14:07:00

DISTANCE

PROTECTION

ACTED (REASON

AWAITED)


8 220 kV

SABARGIRI -

THENI

20-03-

2015/

13:08:00

20-03-

2015/

13:46:00

TRIPPED ON R-Y-

PH FAULT

KSEB/

TNEB

TNEB: Temporary line fault. AR

operated & subsequently lockout at

Theni end. KSEB:

9 400 Kv

KRISHNAPATNAM

- NELLORE

20-03-

2015/

03:02:00

DISTANCE

PROTECTION

APGENC

O/

APTRANS

CO

To-be-discussed

10 400 Kv

KRISHNAPATNAM

- CHITTOOR

20-03-

2015/

05:05:00

20-03-

2015/

05:29:00

DT RECEIVED AT

KRSNPTNM

APGENC

O/

APTRANS

CO

To-be-discussed

11 400 kV

KHAMMAM -

MAMIDIPALLY 1

21-03-

2015/

13:09:00

21-03-

2015/

13:56:00

B -N FAULT PGCIL

(SR-I)/

TSTRANS

CO

PGCIL (SR-I):The feeder Auto

reclosed and tripped on B-N persistent

fault in line.

TSTRANSCO:

12 400 kV KAIGA -

GUTTUR 1

21-03-

2015/

17:44:00

21-03-

2015/

18:44:00

DT RECEIVED AT

KGA END

KAPS/

KPTCL

To-be-discussed

ANNEXURE- IV

2

13 400 kV KAIGA -

GUTTUR 2

21-03-

2015/

20:03:00

21-03-

2015/

20:30:00

DT RECEIVED AT

KGA END

KAPS/

KPTCL

To-be-discussed

14 400 kV KAIGA -

GUTTUR 2

21-03-

2015/

17:44:00

21-03-

2015/

18:58:00

DT RECEIVED AT

KGA END

KAPS/

KPTCL

To-be-discussed

15 400 kV

KHAMMAM -

KALPAKKA 1

22-03-

2015/

14:05:00

22-03-

2015/

20:55:00

B-N FAULT PGCIL

(SR-I)/

APTRANS

CO

PGCIL (SR-I): The feeder Auto


fault in line

APTRANSCO:

16 400 kV

KHAMMAM -

KALPAKKA 2

22-03-

2015/

12:53:00

22-03-

2015/

13:28:00

R - N FAULT PGCIL

(SR-I)/

APTRANS

CO



fault in line

APTRANSCO:

17 400 kV

KHAMMAM -

KALPAKKA 2

22-03-

2015/

14:45:00

22-03-

2015/

20:57:00

B-N FAULT PGCIL

(SR-I)/

APTRANS

CO



fault in line

APTRANSCO:

ANNEXURE- IV

3

18 400 kV

KHAMMAM -

MAMIDIPALLY 1

22-03-

2015/

12:01:00

22-03-

2015/

20:21:00

B - N FAULT PGCIL

(SR-I)/

TSTRANS

CO



fault in line

TSTRANSCO:

19 400 kV

KHAMMAM -

KALPAKKA 1

22-03-

2015/

13:36:00

22-03-

2015/

13:58:00

B-N FAULT PGCIL

(SR-I)/

APTRANS

CO



fault in line

APTRANSCO:

20 400 kV

KHAMMAM -

MAMIDIPALLY 1

25-03-

2015/

18:32:00

25-03-

2015/

19:15:00

B-N FAULT PGCIL

(SR-I)/

TSTRANS

CO



fault in line

TSTRANSCO:

21 220 kV

AMBEWADI -

PONDA 2

25-03-

2015/

16:15:00

DISTANCE

PROTECTION


22 400 kV KAIGA -

GUTTUR 1

27-03-

2015/

13:40:00

27-03-

2015/

15:26:00

TRIPPED WHILE

CHECKING RELAY

KGS/KPT

CL

To-be-discussed

ANNEXURE- IV

4

23 400 Kv RAICHUR

PG - GOOTY 1

28-03-

2015/

19:34:00

28-03-

2015/

19:52:00

TRIPPED DURING

RELAY TESTING

AT RAICHUR

PGCIL

(SR-I)

To-be-discussed

24 220 kV

AMBEWADI -

PONDA 1

28-03-

2015/

11:01:00

28-03-

2015/

11:24:00

TRIPPED ON B-N

FAULT


25 400/220 kV ICT-2

AT MAHABOOB

NAGAR

28-03-

2015/

06:40:00

RESTRICTED

EARTH FAULT

TSTRANS

CO

To-be-discussed

26 400 Kv ALM -

SVCTM-II

29-03-

2015/

15:29:00

29-03-

2015/

16:51:00

B -N FAULT TNEB R-N fault at the time of 400 kV

Alamathy - Sunguvarchatram - I

Feeder tripping. (Both the feeders in

the same tower).

ANNEXURE- IV

5

27 400/230 Kv ICT-1

AT

SUNGUVARCHAT

RAM

29-03-

2015/

15:29:00

29-03-

2015/

16:32:00

OVER FLUX

PROTECTION

OPERATED

TNEB It is 400/110kV ICT-3 at

Sunguvarchatram. On 29.03.2015 @

15.29.38Hrs., 400/110KV,

3×66.67MVA, ICT-3 tripped on V/f

trip due to sudden rise in voltage

(around Va=321 & Vc=333KV) and

actuation of V/f Trip of ICT-3 occurs

few milliseconds after the fault

tripping of 400KV Alamathy-1 Feeder

and 400KV Alamathy-2 feeder. ICT-3

was put back into service at 16:30:18

Hrs

28 400 Kv ALM -

SVCTM-I

29-03-

2015/

15:29:00

PHASE TO PHASE

FAULT

TNEB Line Fault due to jumper cut in B

phase. Feeder normalised on

30.03.2015 @ 12:10 hrs. after

attending the fault.

29 220 kV

AMBEWADI -

PONDA 1

30-03-

2015/

13:10:00

30-03-

2015/

20:40:00

B - N FAULT KPTCL To-be-discussed

30 400 Kv VTPS -

MALKARAM 2

30-03-

2015/

11:51:00

30-03-

2015/

20:41:00

R -N FAULT APGENC

O/

TSTRANS

CO

To-be-discussed

ANNEXURE- IV

6

31 400/220 kV ICT-1

AT BTPS

31-03-

2015/

05:06:00

REASON AWAITED KPCL To-be-discussed

32 400 kV KURNOOL -

SRISAILAM

01-04-

2015/

15:01:00

01-04-

2015/

15:30:00

B-N FAULT APTRANS

CO/

TSGENCO

To-be-discussed

33 400 kV

HYDERABAD -

KURNOOL

01-04-

2015/

13:01:00

01-04-

2015/

13:45:00

TRIPPED PGCIL(SR-

I)/

APTRANS

CO

To-be-discussed

34 400 kV

HYDERABAD -

KURNOOL

01-04-

2015/

15:01:00

01-04-

2015/

17:34:00

TRIPPED PGCIL(SR-

I)/

APTRANS

CO

To-be-discussed

35 400 kV KURNOOL -

SRISAILAM

01-04-

2015/

13:01:00

01-04-

2015/

13:46:00

B-N FAULT APTRANS

CO/

TSGENCO

To-be-discussed

36 220 kV IDUKKI -

UDUMALPET

03-04-

2015/

16:39:00

03-04-

2015/

17:25:00

TRIPPED ON B-PH

FAULT

KSEB/

TNEB

TNEB: Temporary fault due to heavy

rain at Edukki area. AR operated &

Lockout at Udumalpet end.

KSEB:

ANNEXURE- IV

7

37 400 Kv NCTPS -

VALLUR 2

03-04-

2015/

22:10:00

DIFFERENTIAL

PROTECTION

OPERATED

TNEB/

NTECL

TNEB: No visible fault. AR operated

& holding at Vallur end.

NTECL:

38 400 kV

DICHIPALLY -

RAMAGUNDAM

05-04-

2015/

13:43:00

05-04-

2015/

22:23:00

R - N FAULT TSTRANS

CO/ NTPC

NTPC: The line tripped on R-N fault

at 13:43 Hrs on 5/4/2015. An attempt

was made to charge from Dichipally

end at 15:40 hrs. But it tripped on

SOTF. APTRANSCO have informed

that they rectified the fault.

Subsequently, it was charged from

DICHIPALLY end, but it has tripped

on over voltage at ramagundam end.

Finally the line was charged from

RDM end at 22:30 hrs and

subsequently synchronized at

dichipally end.

APTRANSCO:

39 400 kV GUTTUR -

NARENDRA 2

06-04-

2015/

17:07:00

06-04-

2015/

17:23:00

H/T BY MISTAKE

BY NARENDRA

OPERATOR

KPTCL/

PGCIL

(SR-II)

To-be-discussed

40 220 kV SEDAM -

TANDUR

06-04-

2015/

13:53:00

06-04-

2015/

16:25:00

OCR OPERATED KPTCL/

TSTRANS

CO

To-be-discussed

ANNEXURE- IV

8

41 400 Kv NCTPS -

VALLUR 2

07-04-

2015/

02:41:00

DIFFERENTIAL

PROTECTION

OPERATED

TNEB/NT

ECL

To-be-discussed

42 400 Kv NCTPS -

VALLUR 2

07-04-

2015/

23:13:00

TRIPPED ON Y-PH

FAULT

TNEB/NT

ECL

To-be-discussed

43 400 Kv NCTPS -

VALLUR 1

08-04-

2015/

22:28:00

TRIPPED ON R-PH

FAULT

TNEB/NT

ECL

To-be-discussed

44 HVDC TALCHER -

KOLAR POLE

09-04-

2015/

12:04:00

09-04-

2015/

14:18:00

CONVERTER

TRANSFORMER R

PHASE OLTC PRD

OPERATED

PGCIL

(SR-II)

To-be-discussed

45 765 KV RAICHUR -

KURNOOL

10-04-

2015/

18:45:00

10-04-

2015/

21:16:00

Y-B FAULT PGCIL

(SR-I)

To-be-discussed

46 400 Kv

KAYATHAR -

KARAIKUDI 1

11-04-

2015/

09:58:00

SF6 LEAKAGE IN

REACTOR

BREAKER

TNEB To-be-discussed

47 400 kV

TALAGUPPA -

NEELAMANGALA

11-04-

2015/

02:22:00

11-04-

2015/

02:49:00

Y-N FAULT KPTCL To-be-discussed

ANNEXURE- IV

9

48 400 kV

MAHABOOB

NAGAR -

RAICHUR

11-04-

2015/

18:07:00

11-04-

2015/

18:50:00

TRIPPED ON R-PH

FAULT

TSTRANS

CO /KPCL

To-be-discussed

49 400 Kv NCTPS -

VALLUR 1

11-04-

2015/

04:29:00

DIFFER

PROTECYION IN R-

EARTH DUE TO

FOG & 220 KV LINE

TRIPPING DUE TO

FOG

TNEB/NT

ECL

To-be-discussed

50 765 KV RAICHUR -

KURNOOL

11-04-

2015/

18:04:00

11-04-

2015/

18:55:00

TRIPPED ON Y-B

FAULT

PGCIL

(SR-I)

To-be-discussed

51 220 Kv

REGULAPADU-

ALIPUR LINE

11-04-

2015/

18:13:00

11-04-

2015/

19:20:00

EFR RELAY ACTED APTRANS

CO/

KPTCL

To-be-discussed

52 220 kV SEDAM -

TANDUR

11-04-

2015/

18:12:00

11-04-

2015/

19:36:00

EFR RELAY ACTED KPTCL/

TSTRANS

CO

To-be-discussed

53 400 kV RAICHUR -

BTPS

11-04-

2015/

17:42:00

11-04-

2015/

19:02:00

TRIPPED ON B-PH

FAULT

KPCL To-be-discussed

ANNEXURE- IV

10

54 400/110 kV ICT 2

AT ALAMATHY

11-04-

2015/

11:30:00

11-04-

2015/

17:31:00

SF6 GAS LEAKAGE TNEB To-be-discussed

55 400 Kv RAICHUR

PG - GOOTY 2

11-04-

2015/

18:04:00

TRIPPED AT RCR

END DUE TO LA

FAILURE

PGCIL

(SR-I)

To-be-discussed

56 400 Kv NCTPS -

VALLUR 1

12-04-

2015/

03:47:00

DISTANCE

PROTECTION

TNEB/NT

ECL

To-be-discussed

57 220 kV IDUKKI -

UDUMALPET

12-04-

2015/

01:43:00

12-04-

2015/

02:18:00

B PHASE

DISTANCE

PROTECTION

KSEB/

TNEB

To-be-discussed

58 220 kV IDUKKI -

UDUMALPET

12-04-

2015/

15:12:00

12-04-

2015/

16:26:00

B-N FAULT KSEB/

TNEB

To-be-discussed

59 400 Kv NELLORE -

SPDR

12-04-

2015/

20:37:00

12-04-

2015/

21:11:00

R-N FAULT PGCIL

(SR-I)/

PGCIL

(SR-II)

To-be-discussed

60 400 Kv HASSAN -

UPCL 1

12-04-

2015/

12:58:00

12-04-

2015/

13:23:00

TRIPPED ON B-PH

FAULT

PGCIL

(SR-II)

/KPTCL

To-be-discussed

61 220 kV

GUMMUDIPUNDI -

SULLURPET

13-04-

2015/

17:15:00

13-04-

2015/

17:37:00

DISTANCE

PROTECTION

TNEB/

APTRANS

CO

To-be-discussed

62 400 kV ALAMATHI

- VALLUR 1

13-04-

2015/

19:43:00

DISTANCE

PROTECTION

TNEB/NT

ECL

To-be-discussed

ANNEXURE- IV

11

63 400 Kv HASSAN -

UPCL 1

14-04-

2015/

11:08:00

14-04-

2015/

11:39:00

TRIPPED ON B-PH

FAULT

PGCIL

(SR-II)

/KPTCL

To-be-discussed

64 400 kV

GHANAPUR -

MAMIDIPALLY

14-04-

2015/

03:42:00

TRIPPED AT MDPL

END ONLY

PGCIL

(SR-I)

/TSTRAN

SCO

To-be-discussed

65 400/220 kV ICT-1

AT BTPS

14-04-

2015/

01:09:00

MAIN

PROTECTION

OPERATED

KPCL To-be-discussed

66 220 kV

YERANDAHALLY -

HOSUR

14-04-

2015/

19:12:00

14-04-

2015/

19:37:00

B - N FAULT KPTCL/T

NEB

To-be-discussed

ANNEXURE- IV

12

Documents

SOUTHERN REGIONAL POWER COMMITTEE - Kar · Minutes of the 42nd PCSC Meeting held on 26-03-2015 Page 1 SOUTHERN REGIONAL POWER COMMITTEE BENGALURU Minutes of the 42nd Meeting of Protection