Mailing list1) Chief Engineer (LD), MSETCL, Kalwa. Fax-27601769/652) Chief Engr. (Trans O&M), MSETCL, Bandra. Fax No. 022 - 26590808/26598587.3) CE (W), MSEGCL, 3rd floor, Prakash gad, Mumbai.4) S.E. (T&C), MSETCL, Aurangabad Fax-0240-2234220 /23462905) S.E (T&C), MSETCL, Pune. Fax-9520-2617532/26123426) Dy. CE (T&C), MSETCL, Koradi, Nagpur. Fax- 07109 - 2621627) S.E.(T&C), MSETCL, Vashi Fax- 022-276560398) S.E.(Testing), Bhusawal, Dist: Jalgaon Fax-02582-2503799) S.E. (Task Force), MSPGCL, Nagpur Fax- 0712-2591717.10) S.E.(TCC), MSETCL, Karad. Fax.No. 02164 25511811) Chief Engineer (Gen), GSECL, H.O. Baroda. Fax-0265-5512129/234453712) S.E. (Testing), GETCO, Baroda. Fax-0265-235121813) Chief Engineer (LD), MPPTCL, Jabalpur, Fax - 0761- 2664343 / 2970119.14) E.D. (T&C), MPPTCL, Jabalpur. Fax-0761-270271015) ED (Engg.) MPPGCL, Jabalpur Fax- 0761-266006316) Chief Engineer (LD), CSPTCL, Raipur. Fax-0771 - 257417417) C.E. (T&C), CSPTCL, Raipur.Fax-0771-257474918) EE (T), CSPGCL- Fax.No. 07789-22622719) S.E. (T&C), CSPTCL, Bhilai. Fax.No. 0788 - 228156120) S.E. (T&C), CSPTCL, Raipur. Fax No.0771 - 2574749.21) EE, Division VIII (MRT),Elect. Dept; Goa Fax 0832-2735124.22) Supdt.Engr., Electricity Dept., DNH, Silvasa. Fax : 0260-264233823) Executive Engr., Electricity Dept. DD. Fax: 0260-225088924) D.G.M. (O.S. ),N.T.P.C., Mumbai, Fax- 2821669225) DGM, NTPC WR – II, Raipur, Fax: 0771 - 254455026) D.G.M. (EM), KSTPS, NTPC, Korba Fax 07759-233088 (Tele fax: 232440)27) DGM (EMD), VSTPS, NTPC, Vindhyachal Fax-07805-24771328) DGM (EM-I), NTPC, SIPAT Fax-07752-246506 (Tele fax: 246691)29) AGM (O&M), KGPP, Adityanagar, Surat Fax 0261-2861428/286143330) Sr.Supdt. (EM), Gandhar, NTPC Fax-02642-87402 / 8745031) DGM (O.S.), WRLDC, Mumbai Fax-2823543432) DGM, WRTS-I, POWERGRID, Nagpur, Fax- 0712- 2631051 / 64136633) AGM, WRTS-II, POWERGRID, Baroda Fax-0265-2480952 (Tele fax: 2487542)34) SME (E), TAPS-3&4,Tarapur Fax 02525-282001/28207335) Maintenance Superintendant, TAPS –1 & 2, Tarapur.Fax- 02525-28212136) SME(E), NPCIL , Kakrapara Fax 02626-23426637) GM (Maint.). TORRENT Power., Ahmedabad.Fax-079-2750667938) AGM (QAIT), TPC, Trombay. Fax –022-6668708839) Asst. VP, Dahanu TPS Fax- 952528-222576 / 22203940) GM (O & M), Reliance Infrastructure Limited, Mumbai Fax-3009448841) GM (Electrical), JPL, Raigarh, Fax. No. 7767-281995, 281993.42) AGM (OS), NSPCL, New Delhi . Fax.No.011 26717381/26717363/2671736643) Vice President, APL, Ahmedabad 079-2555717644) GM, RGPPL, Anjanwel, Guhagar, Ratnagiri, Fax.No. 02359 24107145) GM, JSW Energy Ltd., Jindal Mansion, Mumbai- Fax.No.022 2352640046) GM, CGPL, Mundra Fax.No. 02838 66118847) Director (G M Division), CEA, New Delhi. Fax.No.011-26109750

1  

MINUTES OF THE 121st PROTECTION COMMITTEE MEETING OF WRPC

HELD ON 15/16.05.2014 AT TATA POWER MUMBAI.

The 121st meeting of the Protection sub-Committee was held at TATA POWER, Mumbai on

15.05.2014. The list of participant is enclosed at Annex-1.

Shri S D Taksande, Member Secretary, WRPC welcomed the participants of the meeting. He

thanked TATA POWER for making excellent arrangements for the meeting with a short

notice/request.

He informed that Hon’ble CERC vide its Order in Petition No.167/SM/2012 have made

serious observations on issues pertaining to the protection relaying system and other

irregularities that resulted in the grid disturbances of 30/31.07.2012. He further informed that

Hon’ble CERC has categorically appreciated the efforts of testing team of WRPC

comprising of Shri Satpute SE(TCC), Vashi MSETCL, Shri G.T.Jawale of TPC, Shri

Satyanarayan S., SE(P)WRPC and Shri P.D.Lone EE(P) WRPC in clearly bringing out the

initiation cause of the grid disturbance. The above order also addresses various issues

pertaining to anomalies in ATC/TCC calculations and directed NPC to constitute National

Reliability Council with the object of computation of ATC/TTC, develop reliability standards,

suggest optimum outage planning and congestion management mechanism, etc.

He further informed that followup regarding the implementation status of the protection audit

observations is required to be filed with the Hon’ble Commission and the issue regarding

submission of the data is slated for discussions in the meeting. Other important issue slated for

discussion in the meeting is the revision in SPS setting/logic for secure operation of “All

India grid” post synchronization of SR with NEW grid, by NLDC on persistence follow up by

WRPC.

He also requested Shri S.G.Patki, Chief QAIT, TPC to share the recommendations of the

report of the Task force constituted by CEA under the Chairmanship of Shri Ramakrisna to

analyze / suggest remedial measure and guidelines for islanding scheme, protection audit etc.,

since Shri S.G.Patki was a member of the Task Force.

Shri S.G Patki, Chief QAIT, TPC welcomed all the participant of the meeting. He stated that

protection relaying systems is a hotly debated topic post 30/31.07.2012 grid disturbance. He

briefly appraised the members with the recommendations of the Task Force in the area of

protection audit, model relay setting calculations and guide lines for relay settings. He further

stated that the CBIP protection manual is under review and all the recent developments in

2  

protection relaying system would be included in the CBIP manual. Further he stated that the

accreditation of protection auditing agencies has been discussed in the recently held CBIP

conference and criterion/requirements for the such agencies would come up in the near future.

This would help utilities in identifying the agencies for carrying out third party protection

audits.

MS, WRPC requested Shri P.D.Lone, EE(P), WRPC to take up the agenda for discussion.

ITEM NO.1: CONFIRMATION OF MINUTES OF 120th PROTECTION

COMMITTEE MEETING

EE (P) WRPC stated that Minutes of the 120th PCM, held on 09.01.2014 at Mumbai were

circulated vide WRPC letter No. WRPC/Protection/120PCM/2014/1469 dated 13.02.2014 and

no comments were received on the same.

Committee confirmed the minutes circulated vide above referred letter without any

modification.

ITEM NO.2: SYSTEM DISTURBANCES

2.1 Occurrence on 17.12.2013 at 220 kV Khaparkheda S/s: MSETCL representative

stated that on 17.12.2013 at 23:31 Hrs the synchronizing PT of Y phase of 220 kV GT III

failed at 220 kV Khaparkheda S/s. The PT got burst and oil splashed out on B phase CT of

GT-III and nearby gantry structure. The overall differential protection of 220kV GT-III bay

operated and isolated the fault from 220kV side. However since there was no CB on LV

side of GT, the fault was fed by the Generating unit –III and the O/C & E/F relay operated,

this resulted in operation of the LBB protection and tripped all the 220kV elements

including the B/C connected to the Bus-I. The 220kV K’Kheda-400kV K’Kheda I/C-II

tripped on O/C protection.

The total generation loss during this event is 242 MWs due to tripping of Unit 1 & 3. He

informed that the synchronizing (Bus) PT was 20 years old. The Tan-Delta was found to be

in order during routine testing of the PT.

All the elements were restored by 02:41 hrs of 18.12.2014 except Unit#3 which was

restored at 19:24hrs of 18.12.2014.

Committee observed that the operation of LBB was in order due to operation of

backup protection of the Unit#3 and the fault was kept feeding from LV side of the

3  

GT of Unit#3 even though it was isolated from HV side of the GT, resulting in a stuck

breaker like condition. It was further recommended that the older instrument

transformers are required to be monitored closely, by carrying out DGA analysis of

the oil, so as to ascertain the deteriorating condition of the equipments.

2.2 Occurrence on 02.01.2014 at 220 kV Butibori S/s: MSETCL representative intimated

that on 02.01.2014 at 20:45 Hrs at 220 kV Butibori S/s, R phase PT of bus I got burst, led

to operation of busbar protection, resulted in tripping of all elements connected to it.

He further stated that this newly commissioned PT failed within 10 days after

commissioning. Complete testing of the PT was carried out before commissioning of the

PT.

Committee felt that the operation of Bus-bar protection on failure of Bus PT was in order.

However the committee observed that the failure of PTs within such a small span is a

matter of concern.

2.3 Occurrence on 12.01.2014 at 220 kV Butibori S/s: MSETCL intimated that on

12.01.2014 at 13:53 Hrs at 220 kV Butibori S/s, B - ph PT of 220 kV main Bus-II got burst

led to operation of busbar protection which resulted in tripping all elements connected to it

Committees observations were as recorded for Item 2.2.

2.4 Occurrence on 15.01.2014 at 220 kV Mudshingi S/s: MSETCL intimated that on

15.01.2014 at 09:39 Hrs ‘R’ phase CT of 220 kV Mudshingi – Karad IV got burst and led to bus

bar operation at 220kV Mudshingi S/S. The 220 KV Wathar - Mudshingi line tripped at Wathar

end & 220 KV Karad –Wathar line tripped at Karad end on B phase (Z-3) due to flame of failed

R phase CT of Karad Ckt IV spread to B phase CT of Wathar Ckt at Mudshingi Substation. He

further informed that the failed CT was of Areva make live tank CT. The resistive reach of the

220 KV Wathar - Mudshingi & 220 KV Karad –Wathar lines was revised.

Total load loss during this event was 189 MWs for 0.38 Hrs in Kholapur district. Report

received from MSETCL is enclosed at Annexure – 2.4.

Committee observed that the operation of BB protection due to failure of CT was in order.

However the tripping of 220 KV Karad –Wathar & 220 KV Wathar – Mudshingi lines in

Zone-3 was undesirable. Corrective actions taken by MSETCL in revising the resistive

reach setting of Zone-3 post occurrence was in order.

4  

2.5 Occurrence on 17.01.2014 at 400 kV Torora S/s: APL representative intimated that on

17.01.2014 at 01:26 Hrs at 400 kV Tirora, bushing of B phase GT III failed, this led to tripping

of unit 3 along with ST 3 on differential protection due to damage of its lightening arrester. At

01:35 Hrs, due to coal feeder tripping, GT 2 and Unit 2 of APML Tirora tripped. At 1:36 Hrs,

the CB of GT 3 got closed and tripped repeatedly resulting in feeding the fault from the system.

This resulted in operation of differential protection of GT, thus Unit 1 got tripped, while feeding

the fault to GT 3. The fault was sensed by the relay of 400 kV Warora-Tirora 1 and 2 in Zone 4

(reverse zone). The 400 kV Tiraora-Warora II tripped from Tirora end resulting in high voltage

at Tirora end. This resulted in overvoltage stage 1 operation from Tirora end for the line and DT

was send to Warora end. During the incidence, net generation loss was 1857 MWs.

He further informed that the closing of the GT 3 CB might have been due to spilling of burnt oil

on the control cables resulting in shorting of DC supply and initiation of CB close command.

The tripping of GT Unit-1 might have tripped due second harmonics during repeated closing and

tripping of Unit#3 CB.

Committee observed that the operation of over all differential protection of the GT#3 due

to failure of LA was in order. Tripping of over all differential protection of the GT#1 due to

second harmonic fed by this GT was not in order, since energizing a transformer on the

power system can cause sympathetic magnetizing inrush currents to flow in an already

energized parallel transformer. Energizing the second transformer causes a voltage drop

across the resistance of the source line feeding the transformers. This voltage drop may

cause a saturation of the already energized transformer in the negative direction. This

saturation causes magnetizing inrush current to supply the flux. The magnitude of the

magnetizing inrush current is generally not as severe. Therefore the over all differential

protection of GT#1 needs to be tested thoroughly. The tripping of 400 kV Warora-Tirora 1

and 2 in Zone 4 (reverse zone), might be due to sensing the fault in reverse direction,

however appropriate time delay for tripping the lines on faults in reverse direction be kept

and should not be instantaneous. APL may check and confirm the same.

2.6 Occurrence on 17.01.2014 at 400 kV Indore S/s: MPPTCL representative intimated that

on 17.01.2014 at 06:05:41 Hrs, a fault occurred on Y phase of 400 kV Indore – Itarsi – I,

followed by opening of Y phase breaker. At 06:05:42 Hrs circuit was auto reclosed, however

since the fault was not cleared the main 2 of the line operated and after 40msec all the three

poles of the breaker opened. Simultaneously the bus bar protection of Main Bus-II also operated

and all elements connected to this bus tripped. He informed that the Bus bar protection is old

5  

EE make electromagnetic FAC34 type and is kept out, the relay would be replaced shortly. He

further informed that the relay has mal operated in the recent past after extension of Bus Bar

scheme for 400kV Indore (PGCIL) Ckt-I & II and MPPTCL has requested PGCIL for

rectification of fault in the integration of scheme to avoid recurrence of such incidences. PGCIL

representative informed that they have already checked and there is no fault in their system.

There was no loss of load during the event. All elements were restored by 08:08 Hrs. Report

received from MPPTCL is enclosed at Annexure 2.6.

Committee observed that operation of Bus Bar protection for through fault was not

desirable and MPPTCL was requested to replace the old EE make BB protection scheme

by numerical BB protection scheme at the earliest.

2.7 Occurrence on 21.01.2014 at 400 kV Chandrapur S/s: MSETCL representative intimated

that on 21.01.2014, at 18:53 Hrs Y-phase pole of Chandrapur -2 end CB of 400 kV Chandrapur

2-Warora ckt I got bursted. This resulted in operation of Bus bar protection of 400 kV Bus I at

Chandrapur 2 leading to tripping of 400 kV Chandrapur 2-Warora I, 400 kV Chandrapur 2-

Warora II, 400 kV Chandrapur 2-Dhariwal I. The tripping of 400kV Chandrapur 2-Dhariwal ckt

I, the 150 MWs generation at Dhariwal was also lost and due to large voltage dip during fault,

Chandrapur Unit 7 (350 MW) tripped as its auxiliaries tripped on under voltage. During the

event, 400kV Wardha-Warora I also tripped on DT received at Warora end which is a suspected

tripping. The tripping of 400kV Chandrapur 2-Warora both ckts, the whole Tirora generation

was diverted to Wardha. Due to inrush of power at Wardha, the 400kV Wardha-Parli each ckts

flow crossed 750 MW resulting in operation of SPS for 765kV Solapur-Raichur from Wardha.

The SPS signal generated was S3 and S4. S3 signal resulted in load shedding at Kolar known as

Kudankulam load loss and S4 signal lead to generation back down at Mouda (Unit not supposed

to trip but tripped) and Tirora (IEPL was not generating). With the SPS operation in SR and

WR, power swing was also observed on 765kV Solapur-Raichur line.

There was a second occurrence, at 19:02 Hrs, Due to fire in Y phase Wavetrap of 400 kV

Chandrapur-Chandrapur 2 ckt 1 at Chandrapur end, the line was hand tripped at Chandrapur end

and DT was received at Chandrapur 2 end and tripped. With this Chandrapur 2 left with only

400 kV Chandrapur 2 –Parli 1 and 2 cks, and these lines tripped after 5 and 7 seconds

respectively on overvoltage stage 1 protection from Chandrapur 2 S/s. Also Main CB on Bus I

side for the 400 kV Chandrapur 2-Chandrapur 2 GCR I and 400 kV Chandrapur 2-Chandrapur 2

GCR II bay tripped (only bay is charged).

6  

He further informed that the Siemens make line breaker failed within 10 days after

commissioning. The breaker was put into service after carrying out all the pre commissioning

tests. The failure of breaker was taken up the OEM and after carrying out Dew point and CRM

tests on the healthy poles of the failed breaker, M/s Siemens have opined that there was erosion

on the contacts of the healthy poles of the breaker.

During this incident no system change was observed and no load loss/gen loss /SPS

operation was observed.

Committee felt that operation of BB protection was in order. However tripping of 400

kV Warora-Wardha 2 on DT receipt at Warora end needs to be investigated by

MSETCL. The contact corrosion of the failed breaker is a matter of concern and

should be taken up the OEM.

2.8 Occurrence on 25.01.2014 at 400 kV Navsari S/s: Powergrid (WR - II) representative

intimated that on 25.01.2014 at 07:01 Hrs at 400 kV Navsari S/s, R-E fault occurred on 400

kV Navsari – Vapi – II. After dead time, A/R attempted to close but as fault was persisted,

the line tripped on 3 poles. However, after 100 ms, the LBB of B phase of Vapi bay

maloperated and led to tripping of all elements connected to bus I (The line was connected

to Bus I). All elements were restored by 10:18 Hrs except 400 kV Navsari – Vapi – II.

He further informed that to find the cause of operation of LBB relay @07:01hrs, the

checking of the scheme was undertaken (the 400kV Vapi-Navasari #2 was already out) but

again the LBB protection of B phase Main I BB relay for this feeder operated at around

12:09hrs, although there was no pre condition for LBB operation and the LBB operated

contacts got latched and tripping was not extended to other feeders in service. The LBB

operated contact at 12:48 Hrs, Main-I BB protection was kept in block mode for both the

BB zones(Bus-I & Bus-II) and DC supply of Main I BB relay was switched off so that the

latched contacts could get resseted. However the tripping contacts of B phase Main I BB

relay operated and tripped both 400kV Bus I & II which resulted in tripping of all the

400kV feeders. It was concluded that the B phase element of the ABB make REB 670 relay

has developed hard ware problem. The relay was replaced. All the elements were restored

by 15:38hrs.

Report received from POWERGRID is enclosed at Annex.-2.8.

7  

Committee felt that the operation of the LBB protection was a mal operation and while

checking/testing the LBB/BB protection schemes, it should be ensured that the tripping is

always blocked.

2.9 Occurrence on 30.01.2014 at 400 kV STPS, Sarni S/s: MPPTCL representative intimated

that on 30.01.2014 at 10:55 Hrs, Unit 8 & 11 tripped simultaneously on indication of negative

phase sequence and E/F respectively. It was followed by reduction in line loading of 400 kV

Itarsi – Satpura (85 MWs to 16 MWs). The line was H/T at 11:30 Hrs. The total generation loss

during the event was 243 MWs, 352 MWHrs.

It was observed that fault has occurred on 400kV STPS-Itarsi line resulting in unbalance and

leading to tripping of STPS units # 8 & 11. However unit#8 did not trip during the above

occurrence. PGCIL representative informed that the tripping of line was within 40-50msec. All

elements were restored by 14:38 Hrs.

Committee observed that the sensing of negative phase sequence currents at the units

when the fault was on EHV lines and cleared within 40-50msec was not in order. Further

since the fault was on EHV side, the negative sequence component fed from the unit side

will be negligible/very low because of Generator Transformer.

2.10 Occurrence on 31.01.2014 at 400 kV Padghe S/s: MSETCL representative

intimated that on 31.01.2014 at 16:46 Hrs , 220 kV Bus II supply of Padghe failed due to the

fatal accident to the technician while the maintenance work of 220 kV Padghe-Wada circuit

bay was under going. Due to this, all the 220 kV elements from Bus II tripped resulted in load

loss of 127 MW (Blackout at 220/100 kV Jambhul, 220/100/22 kV Pal-Dombivali, 100/22 kV

Dombivali MIDC and partial at 100/22 kV Taloja S/s due to loss of source feeders i.e. 220 kV

Padghe-Jambhul 1 & 2.

On 31.01.2014, the 220kV Padghe – Wada line was taken out for maintenance work at both

ends. While the Breaker & line side isolator was kept open, 220kV Main B Bus isolator was

closed at Padghe end for the above shutdown. Temporary earthing was provided on both side of

line isolator & line earth isolator. At Padghe end, the maintenance technician got severely

electrocuted & died on spot while trying to provide the temporary earthing on Main bus side of

Y phase pole of breaker. The Earthing rod in the hand of technician came in the induction

zone of live conductor which caused heavy flashover on breaker pole through earthing

rods & human body. Heavy arcing also continued across the breaker pole through the temporary

grounding made on breaker side of the line side isolator. The earthing wires of earthing rods

8  

put on Y phase were also found broken & melted. This created Y-E high arcing nature of fault in

the system on B- Bus at Padghe s/s. Subsequently remote end dist. prot in Zone II/Zone III &

B/U E/F of all the lines connected to 220 kV Padghe Bus picked up including Back up

protections of B/C,ICTs which was feeding the fault also picked up.

The healthy Main Bus-A was isolated from faulty Main Bus – B by tripping of B/C breaker on

operation of Bus bar Back up O/C high set definite time protection. The 315 MVA & 3X200

MVA , 400/220 kV ICT 2 & 4 connected to faulty Bus tripped from HV/LV side on directional

HV B/U E/F protection. The 220 kV grid lines, Temghar II, Vasai & Nasik II which were

connected to faulty bus also tripped from remote end on operation of distance protection

on Y-E fault in Zone II time.

Distance protection at Jambhul end of 220kV Padghe – Jambhul-2 which was on faulted Bus

sensed the Padghe end fault in Y-E, Zone -3 which eventually got converted to Zone II fault

when B/C at Padghe end tripped & finally tripped in Zone 1 due to increase in fault current.

This resulted into AR operation at Jambhul end.

Similarly, the directional E/F at Jambhul end of 220 KV Padghe Jambhul -1 which was on other

Bus section also picked up in forward direction before bus Coupler tripping and eventually

tripped in Zone-I before tripping of the BC. However, the E/F relay might have got resetted

when B/C at Padghe end tripped.

Because of tripping of both Padghe-Jambhul lines -1 & 2 at Jambhul end, the total power failure

occurred at 220kV Jambhul, PAL- Dombivali, Anandnagar , 100kV Dombivali s/s& 100

kV Taloja s/s which was partially feed from PAL- Dombivali. The water works at Jambhul

affected for about 35 minutes

The 220 kV ABB RADSS Bus Bar protection at Padghe end did not operate during this Bus

fault. However the same Bus Bar Protection has correctly operated on 30/05/2013 when 3 phase

fault occurred on both 220 kV Buses. The BB relay was tested and it was found that one of the

Y phase Aux. CT was found saturated. The same was replaced.

He further informed that the officers has been asked to pass on necessary instruction to

substation staff to confirm the isolation of equipment from system & work permit is to be

issued/taken after confirming that the Line /ICT /TF is isolated completely i.e. de-energized

completely from both end/side.

The erratic behavior of ABB REF 615 B/U protection –EF relay of Jambhul -1 at 220kV

Jambhul s/s would be checked. The 220KV breaker of Wada line would be checked thoroughly

9  

for healthiness. To minimize the effect of failure of 220KV long bus 2Nos of Hybrid pass is

being provided on 220KV Bus section to sectionalize existing long bus in to 4Nos bus section

with providing numerical bus bar protection. The ESR from SMS is not found in chronological

order. The matter would be referred to M/S ABB for correction. Report received from MSETCL

is enclosed at Annex-2.10.

Committee observed that care should be taken to see that all the safety operational

procedures are followed while giving permit to work and the officer/supervisor in charge

of such works shall ensure that the equipment under maintenance is de energized from

both the ends and earthed. The non operation of 220 kV ABB RADSS Bus Bar protection

at Padghe S/S was due to saturation of Aux CT. Committee recommended testing of Aux.

CTs for saturation after every heavy bus fault so as to ascertain whether any of the Aux.

CT has saturated during the fault. The tripping of Jambhul -1 & Jambhul-2 at 220kV

Jambhul S/S in Zone-1 needs further investigation.

2.11 Occurrence on 31.03.2014 at 400 kV Nagda S/s: MPPTCL representative intimated

that on 31.03.14 at 05:10 hrs. the 220 kV CVT and LA on “R” phase of 220 kV Nagda – Ujjain

ckt I failed at 400 kV S/s Nagda end. The DPS operated from Nagda end in Zone I and from

Ujjain end in Zone II. But the 220 kV CB at Nagda end did not trip due to problem in “R” phase

tripping relay. Hence this delay caused the operation of LBB protection for this feeder.

Consequently, the 220 kV elements connected on 220 kV Main Bus I tripped, but 220 kV Main

Bus remained charged and unaffected. There was no interruption due to above tripping. The

failed 220 kV CVT and Wave Trap (make : WSI, year of mfg. 1988) of 220 kV Nagda – Ujjain

Ckt. I replaced on 01.04.14. Due to delay in tripping the LBB operation took place. The contact

problem of “R” phase tripping relay (English Electric make 86 relay) was attended and complete

wiring and operation was checked after testing the relay and CB trip test before taking it in to

service.

All elements were restored by 16:38 hrs. Report received from MPPTCL is enclosed at Annex

2.11.

Committee observed that though the DPS for 220kV Nada Ujjain ckt I operated correctly,

the contact problem of 86A relay did not extend the trip command to the CB, this led to

operation of LBB. However the carrier aided tripping from Ujjain end within Zone-I

timings should have taken place instead of clearing the fault in Zone-II. MPPTCL

representative stated that they would sort out the carrier aided trip problem.

10  

2.12 Occurrence on 05.02.2014 at 400 kV New Koyna S/s: MSETCL representative intimated

that on 05.02.2014 at 09:50 Hrs online shifting of 400 KV Karad-II line on TBC at 400KV R.S.

New Koyna was being carried out. All preparatory operations were done sequentially but during

hand tripping of own Circuit breaker, all the feeders on bus-II (400 kV Bus coupler, 400 kV

New Koyna – Jaigadh –II, 400 / 220 kV ICT I & II (spare) , 400 kV New Koyna – Karad II, 400

kV New Koyna – Dabhol II, 400 kV New Koyna – Stage IV –II) tripped with indication of

'Pole discrepancy’. The tripping of feeders on Bus-II was not extended from LBB or Bus bar

Differential Relay, but it was due to extension of positive DC to trip bus while carrying out

online TBC operation of 400KV Karad ckt.-II. Also the PDR indication was due to pick up of

CMR due to DC leakage. The DC Leakage was traced & located in cable from relay panel to CB

MK box of 400 KV Karad-I and was attended.

All elements were restored by 14:12 Hrs of 05.02.2014. Report received from MPPTCL is

enclosed at Annex-2.12.

Committee felt that indication circuits are as important as any other circuits, therefore

attention shall be given to see that these circuits are healthy during the routine

maintenance. The DC leakage could have been detected through the “DC Earth leakage”

indication if it would have been healthy.

2.13 Occurrence on 16.02.2014 at 400 kV Talandage S/s: MSETCL representative

intimated that on 16.02.2014 at around 00:46 Hrs, main Zone-2 Bus bar protection of 220kV

Bus B operated at 400kV Mudshingi S/S. During yard inspection it was observed that 220 KV

Mudshingi - 2 bay ‘Y’ phase isolator rod of 29LC isolator was lying on the ground and ladder

was placed on ‘C’ Isolator. After detailed investigation it was concluded that there was a theft

attempt and flashover took place during un installation of Aux Bus ‘Y’ phase isolator leading to

Bus bar operation. During this event there was no loss of load. All lines / ICTs were restored by

02:05 Hrs on 04.08.2013. Report received from MSETCL is enclosed at Annex 2.13.

Committee noted.

2.14 Occurrence on 09.03.2014 at 400 kV Amaravati S/s: MSETCL representative intimated

that on 09.03.2014 at 21:50 Hrs at 400 kV Amaravati S/s, the B phase CT of 132 KV Achalpur

feeder got burst (Tan Δ was 0.019 on 27.05 2013), resulting in bus bar operation. All elements

connected to bus tripped. The failure of CT (Apporva make) in short span of 3 years was not

desirable and hence the would be taken up with the manufacturer. He further stated that the it

11  

has been suggested that testing of other CTs of similar make should be carried out and if the

values are not within the permissible limits it should be reported the manufacturer. The failed

CT was replaced by spare available CT at Morshi and the feeder is charged.

All elements were restored by 17:01 Hrs of 10.03.2014. Due to this incidence, the areas which

were fed from 132 KV Morshi and Warud substations affected for 42 minutes. The total load

loss was around 14 MWs.

Committee felt that the operation of BB protection was in order and immediate

replacement of the CT with deteriorated tan delta values would have avoided the

occurrence.

2.15 Occurrence on 12.03.2014 at 220 kV Pandhurna S/s: MPPTCL representative intimated

that on 12.03.2014 at 15:17 Hrs, 220 kV Sarni – Pandhurna tripped from Pandhurna end on

distance protection zone I, B phase transient fault. While A/R was in process, LBB operated due

to wiring problem, resulted in tripping of 220 kV Pandhurna – Kamleswar and 220 kV

Pandhurna – Chhindwara.

The LBB mal operated due to wrong wiring of trip circuits of CB poles, since Y phase pole

tripped instead of B phase pole. This was due to notation confusion of RYB with ABC. The

wiring was rectified. During this event the total load loss was 34 MWhr for 27 minutes. All

elements were restored by 15:50 Hrs. Report received from MPPTCL is enclosed at Annex 2.15.

Committee observed that operation of LBB was due to wrong wiring and non clearance of

the fault. The wrong wiring of the CB trip coils of the poles should have been noticed

during the pre commissioning test of CB.

2.16 Occurrence on 13.03.2014 at 220 kV SEZ Indore S/s: MPPTCL representative intimated

that on 13.03.2014 at 09:20 Hrs, PT of R phase of 132 kV Bus I got burst, at 220 kV SEZ Indore

S/s which led to bus bar operation. The remaining feeders connected to bus were hand tripped.

Failed 132 KV PT (Make : TELK, 1978) was very old and has damaged other two PTs of same

lot. All these three 132 KV PTs replaced by new 132 KV PTs on 14.03.14 and taken in to

service at 11.:20 hrs. During this event the total load loss was 180 MW, 42.93 MWHr. All

elements were restored by 11:20 Hrs of 14.03.2014. Report received from MPPTCL is enclosed

at Annex 2.16.

Committee noted.

12  

2.17 Occurrence on 15.03.2014 at 400 kV Bina S/s: MPPTCL representative intimated that on

15.03.2014 at 13:20 Hrs, 220 KV Bina – Shivpuri feeder tripped on a transient fault from both

ends. However main breaker trip coil of 220 kV Bina – Shivpuri got burnt, thus the breaker got

struck up and led to LBB operation of main bus I. Faulty trip coil was replaced and wiring &

mechanism of the CB was checked thoroughly for any discrepancy, nothing noticeable was

detected.

There was no loss of load during the event. All elements were restored by 16:02 Hrs. Report

received from MPPTCL is enclosed at Annex 2.17.

Committee observed that the trip coil faulty indication would have detected the problem

and suggested that healthiness of all the indications should also be ensured/corrected

during routine maintenance of the CB.

2.18 Occurrence on 16.03.2014 at 220 kV Chikhali S/s: MSETCL representative intimated

that On date 16.03.2014 at 20:10 hrs the Y phase CT of 220 KV Chikoli - Jalana Circuit –I at

220 KV Chikhali substation was got burst, led to busbar operation. It resulted in tripping of all

220 kV feeders & ICTs connected to the bus. The Jalna Ckt-I bay was commissioned on

07.08.2013. The failed CT was of Make-SCT, Gaziabad ,Sr. No. 2009/1411 DOC- 07.08.2013.

The other two CTs SCT make installed on R & B Ph were also tested and Tan-Delta of R Ph CT

was found 0.196 % & that of B Ph CT was found 1.17 % . It has been recommended that the B

Ph CT having high Tan Delta values i.e. above permissible limit should be replaced before

charging the circuit. The failed CT has not been replaced due to non availability of spare CT.

During the event there was no load loss. The elements were restored by 20:53 Hrs and Jalna

lines were restored on 20.03.2014. Report received from MSETCL is enclosed at Annex 2.18.

Committee felt that the operation of BB protection was in order and failure of CTs within

such a short span after commissioning is a matter of concern.

2.19 Occurrence on 17.03.2014 at 220 kV Amaravati S/s: MSETCL representative intimated

that on date17.03.2014 at 13:36 Hrs the insulator string of R phase of 132 KV Amaravati -

Ambazari busted, broke down and slipped, led to R - E fault. The distance protection relay of

the feeder operated and the CB tripped and then auto-reclosed. As the fault was persisting the

relay operated again and the CB tripped and locked out. However the bus bar relay of the 132

KV bus operated and tripped all the bays connected to the affected bus. When the insulator

13  

string (tension string of cut point) got broken, the R phase conductor slipped and fell towards the

middle cross arm i.e. towards Y phase. This resulted in R-Y fault -upon reclosing of the feeder.

As the conductor at this tower fell down, the tension at the other end of the conductor, over the

string at the take off gantry was lost. The strings, hold hitherto in position by the conductor

tension, got released and the connected jumper (from gantry to the CB) swung towards the bus

isolator and came in contact with the earthed structures. This resulted in the bus fault.

During the incident, total loss of load was around 14 MWs for 10 minutes. All elements were

restored by 21:34 Hrs. Report received from MSETCL is enclosed at Annex 2.19.

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

2.20 Occurrence on 19.03.2014 at 400 kV Rajgarh S/s: Powergrid (WR - II)

representative intimated that on 19.03.2014 at 12:13:56 Hrs at 400 kV Rajgarh S/s, B-E

fault occurred on 400 kV Nagda – Rajgarh – II. After dead time, A/R attempted to close but

as fault persisted, the line tripped on 3 poles. At the same time busbar protection (bus II)

operated, resulted in tripping of all connected elements. It was observed that in the newly

commissioned Kasor#2 Tie bay ( charged as Nagda#2 Tie bay) of 400kV Nagda Rajgarh#2

(contingency arrangement FSC of 400kV Rajgarh Kasor#2), CT star point was found

connected reverse. This led to operation of 400kV Bus-2 BB protection. The same was

corrected and the tie bay taken into service. All elements were restored by 13:45 Hrs of

22.03.2014. Report received from POWERGRID is enclosed at Annex 2.20.

Committee noted.

2.21 Occurrence on 25.03.2014 at 765 kV APML Tirora S/s: APL representative intimated

that on 25.03.2014 at 05.28 Hrs. on 25.03.2014, due to bursting of R phase CT of GT 4 bus fault

occurred on 765 kV Bus I at 765 kV APML Tirora. This resulted in tripping of Unit 4 along

with the 765 kV Bus I at APML. Unit 4 tripping has resulted in loss of 639 MWs generation.

Committee noted.

2.22 Occurrence on 31.03.2014 at 400 kV ACBIL S/s: WRLDC representative intimated that

on 31.03.2014 at around 12:39 Hrs, 400 kV D/C ACBIL-Bilaspur line tripped on B phase to

earth fault in Zone-1 indication, since the other circuit 400 kV ACBIL-Bilaspur 2 was already

under shutdown, therefore complete supply failed at ACBIL. This has resulted in generation loss

of 302 MWs.

Committee noted.

14  

Committee observed that most of the above disturbance occurred due to failure of CTs

and PTs. Since the CTs & PTs fall in BB differential zone, it results in tripping of the Bus.

Therefore efforts should be made to avoid failures of the instrument transformers by

carrying out regular condition monitoring of these equipments. Further it suggested

WRLDC to make a compilation of the details (Make, Year of Manufacture, Type, testing

results before failure if carried out etc..) of the failed CTs & PTs.

ITEM NO. 3: Tripping of lines / ICTs: The minor incidences of tripping of lines and ICTs

during the period 01-12-2013 to 31-03-2014 were discussed and are enclosed at Annexure–3.

Committee suggested that the utilities may indicate as to whether A/R is provided on the

lines and whether the A/R for transient fault was successful or the A/R locked out for

permanent faults, in their line/element trippings.

ITEM NO. 4: Hon’ble CERCs orders on the Grid disturbance of 30.07.2012 &

30.07.2012. 4.1: Status of compliance of the Protection Audit observations (Petition No.

220/MP/2012). 4.1.1 : Back ground :

CERCs vide order dated 21.02.2014 in petition No. 220/MP/2012 filed by

POWERGRID have observed that “since the protection system is a vital requirement

for the safe and secure operation of the grid, we have decided that in order to implement

the recommendations of the Protection Audit, a compliance mechanism with definite

time line needs to be put in place”.

The compliance mechanism with definite time line is as under:

(a) Each STU and CTU shall submit its action plan against each deficiency within one

month from issue of this order clearly stating the deficiencies which can be corrected

without any procurement (Category-A) and deficiencies involving procurement of

equipment (Category-B). However, action plan for deficiencies dealt in Petition No.

146/MP/2013 shall be submitted therein;

15  

(b) The remaining deficiencies, if any, in Category-A shall be rectified by the

concerned STU and CTU within 2 months of issue of the order and compliance

report in this regard shall be submitted to respective RPC.

(c) As protection is a matter of critical importance, a time period of one year, as

informed by various agencies in RPC for rectifying the deficiencies, which involve

procurement, cannot be allowed. All deficiencies of Category-B shall be rectified

within 6 months of issue of the order. In this regard, reasons of non-availability of

fund or delay in procurement process shall not be accepted. The procurement and

implementation is to be completed by each STU using their own fund which can be

reimbursed through a common request of funding through PSDF forwarded

through RPCs as per procedure recently approved by Government of India.

(d) Each SLDC shall be responsible to monitor the action taken by STU. If any

deficiency in the STU system in regard to the Category-A deficiencies is not corrected

after 3 months of issue of this order, the concerned SLDC may approach the respective

State Commission for appropriate action against defaulting State entity in accordance

with State Grid Code. The Office-in-Charge of the concerned SLDC shall be responsible

for monitoring and ensuring compliance of the action plan and filing of the petition as

directed herein.

(e) RPCs at the end of each quarter shall prepare a report on the protection deficiencies

and their rectification which shall be sent to this Commission with a copy to CTU not

later than 45 days of expiry of the quarter. The report shall inter-alia identify deviations

from time lines as well as the State sub-stations which have interface with ISTS system.

CTU shall take necessary action and issue a show cause notice for disconnection to sub-

station of STU for not complying with the Standards for Protection and Control as per

Central Electricity Authority (Technical Standards for Construction of Electric Plants

and Electric Lines) Regulations, 2010 and Central Electricity Authority (Grid Standards)

Regulations, 2010.

Further the Hon’ble Commission had directed CTU, STUs and Generating Companies

/Stations of all the regions to ensure rectification of defects in the protection system as

pointed out in the protection audit within the time frame specified above and submit the

latest status of corrective actions to Member Secretary of the respective Regional Power

Committee within one month of issue of this order. All RPCs are directed to furnish

16  

consolidated report with their observations/recommendations to the Commission within

2 months of issue of this order. Thereafter, CTU and SLDCs shall submit quarterly

report to the respective RPC latest by 15th day of the first month of next quarter and

RPCs shall submit the report to the Commission latest by 15th day of the second month

of next quarter. The Member Secretaries, Regional Power Committees shall continue

monitoring the protection related issues and bring to the notice of the Commission any

instance of non-compliance of the Regulation 1.5 of the Grid Code in respect of the

protection related issues considered in the instant petition.

In view of the above directions of Hon’ble Commission, SLDCs were requested to

collect and compile the data of respective STU’s and WRLDC was requested to collect

and compile the data of all the ISGS, Goa, DD & DNH in the format given at Annexure

4.1, by WRPC vide letters dated 05.10.2013 & subsequent email dated 04.12.2013 and

26.03.2014 . The time lines for compliance of the above directives and submission of

data to WRPC is as follows

4.1.2 : Discussions :

Member Secretary requested SLDC’s, WRLDC and CTU to compile the data and

submit the data as per the time line indicated above, in the enclosed format (Annexure-

1) (soft copy in excel sheet – editable on e-mail ids: protectionwrpc@gmail.com; prc-

wrpc@nic.in) at the earliest. He further informed that delay in submission of the

above data may attract non-compliance of the Hon’ble Commissions order.

Updated Data  upto 

Date by which SLDC/WRLDC/CTU shall submit the data to WRPC 

Compliance of the protection Audit deficiencies 

  Category‐A Catagory‐B Upto Feb.‐14  30th March 2014 21st April 2014 21st August 2014 Qtr‐1 (Jan14 to Mar 14) 

25th April 2014   

Qtr‐2 (Apr 14 to Jun 14) 

15th July 2014   

Qtr‐3 (Jul14 to Sep 14) 

15th October 2014   

Qtr‐4 (Oct14 to Dec 14) 

15th January 2015

17  

EE(P) informed that MP, CGPL, APL, NTPC(Vindhayachal), Reliance and

POWERGRID have submitted the data in the above formats. MSETCL,CSPTCL,

GETCO representative stated that they have brought the data with them.

Committee noted.

4.2: Grid Disturbance on 30.07.2012 & 31.07.2012 (Petition No. 167/Suo-

Motu/2012).

4.2.1 : Back ground :

Hon’ble CERCs vide order dated 22.02.2014 in the matter of grid disturbance that took

place on 30.07.2012 & 31.07.2012 in petition No. 167/Suo-Motu/2012, have made

certain studious observations and issued directions.

On the above petition, Hon’ble CERC in its hearing on 10.01.2013, directed the WRPC

Secretariat to submit its views on whether the 400kV Bina-Gwalior line-1 tripping on

load encroachment is correct. Accordingly a team of engineers from WRPC, MSETCL

and TPC did a simulation testing on the relay installed on the line which has tripped

during the above disturbance at 400kV Bina S/S. The results and the conclusions of the

team were presented before the Hon’ble Commission during the hearing held on

20.02.2013.

Member Secretary WRPC stated that the team found that the relay had tripped due to

load encroachment. The reactive reach for Zones 1, 2 and 3 adopted in 400 kV Bina-

Gwalior line-1, Main-II relay were in line with CBIP Protection Guidelines. However,

as per data submitted by POWERGRID, the resistive reach adopted for phase to phase

fault was equal to that for phase to earth fault during the two incidents. POWERGRID

has not provided basis of calculation for the same. However, it is clear that phase to

phase resistive reach is generally smaller than phase to earth resistive reach.

Further POWERGRID have themselves, vide test report dated 10.8.2012, suo-motu

revised these settings and the same were forwarded by WRPC to the Commission and

the revised settings were in order for the resistive reaches. During tests conducted by the

WRPC team, the relay tripped at about 1500 MVA for the first incident and about 1300

MVA for the second incident due to voltage and permitting more loading.

Hon’ble Commission in its above order have appreciated the efforts of protection testing

team of WRPC in clearly bringing out the reason of tripping and inadvertent resistive

18  

reach settings in Main-II relay that caused tripping of the relay which in turn contributed

to the Grid disturbance on both the occasions.

Hon’ble CERC in its above order has suggested various remedial actions to be

implemented by RPCs and constituents including formation of National Reliability

Council with the objection of computation of ATC/TTC, develop reliability standards,

suggest optimum outage planning and congestion management mechanism etc.

4.2.2 : Discussions :

EE(P) requested members to go through the above order, study the measures pertaining

to the respective utilities and comply with the observations/directions relating to their

system. Also all the RPCs have been directed to maintain the relay settings data of all

the ISTS lines and lines eminating from interface S/Ss of Utilities to ISTS and therefore

utilities are requested to submit the data of their system.

Committee noted.

ITEM NO. 5: Status of implementation of recommendations of Report on Grid

disturbance on 30th and 31st July 2012 in WR 5.1 : Back ground :

The Status of implementation in WR on Recommendations of Report on Grid disturbance on

30th and 31st July 2012 as on 15.04.2014 is given at Annexure-5.

In the 117th PCM it was informed that CEA vide letter No. 6/AI/DST/GM-2013/441-449 dated

10.05.2013 has forwarded formats for collecting information of status of action taken on the

recommendations of the Enquiry Committee. The updated status of implementation of various

recommendations of the grid disturbance enquiry committee as on 1st & 15th of each month is

required to be forwarded to CEA by RPCs by 3rd & 17th of every month regularly.

1) Information in Formats 1 to 3 is to be furnished by STU and CTU for month by 1st and

15th of the month.

2) Information in Format 4 is to be furnished by SLDCs/ WRLDC POSOCO for the

month by 1st and 15th of the month.

3) Information in Format 5, 7 & 8 is to be furnished by WRLDC POSOCO for the month

by 1st and 15th of the month.

4) Information in Format 6 is to be furnished by CTU for the month by 1st and 15th of the

19  

month.

In the 117th PCM it was decided that the above information may please be forwarded through

the nodal officer of the above organizations to WRPC.

Nodal officers identified for submission of data were as follows;

1. WRLDC : Shri P.Pentayya GM WRLDC

2. PGCIL-I : DGM(OS)

3. PGCIL-II: DGM(OS)

4. NTPC WR-II : Shri D.Roychowdhari AGM(OS) & A.K.Chandelia DGM(OS)

5. GETCO STU : Shri S.A.Patel.

6. GETCO SLDC : Shri B.B.Mehta, CE SLDC.

7. MSETCL STU : Shri Rajurkar SE

8. MSETCL SLDC : CE SLDC

9. MPPTCL STU : Shri Jain, CE (T&C)

10. MPPTCL SLDC:Shri P.A.R Bende CE SLDC

11. CSPTCL STU:Shri Rehman SE(T&C)

12. CSPTCL SLDC: Shri K.S.Manotia CE SLDC.

In the 120th PCM, it was pointed out that MP was submitting the reports regularly and other

utilities were requested to submit the data in prescribed format in soft copy regularly. It was

also decided that utilities would submit data to nodal agency/officer and nodal agency, after

compiling the data may submit it to the WRPC for timely submission of the same to CEA/MoP.

5.2 : Discussions :

EE(P) stated that MP, WRLDC, POWERGRID and JP Bina are regularly submitting the data.

The nodal officers responsible for compilation of the data may forward the data at the earliest

for onward submission of the same to CEA/MoP. Any change in nodal officer may be

intimated to WRPC.

Committee noted.

20  

ITEM NO. 6: Zone 3 settings of Distance Protection Schemes:

6.1 : Back Ground: CEA have issued Manual on Transmission Planning Criteria which is

effective from 01.02.2013 (the same is available at CEA website). Under para 20 of the

“Manual on Transmission Planning Criteria”, guidelines on zone-III setting to avoid tripping of

lines in extreme loading conditions has been given as follows

Quote

20 Guidelines for consideration of zone-3 settings

20.1 In some transmission lines, the Zone-3 relay setting may be such that it may trip under

extreme loading condition. The transmission utilities should identify such relay settings and

reset it at a value so that they do not trip at extreme loading of the line. For this purpose, the

extreme loading may be taken as 120% of thermal current loading limit and assuming 0.9 per

unit voltage (i.e. 360kV for 400kV system, 689kV for 765kV system). In case it is not practical

to set the Zone-3 in the relay to take care of above, the transmission licensee/owner shall

inform CEA, CTU/STU and RLDC/SLDC along with setting (primary impedance) value of the

relay. Mitigating measures shall be taken at the earliest and till such time the permissible line

loading for such lines would be the limit as calculated from relay impedance assuming 0.95 pu

voltage, provided it is permitted by stability and voltage limit considerations as assessed

through appropriate system studies.

Unquote.

In the 118th PCM all the utilities confirmed that they have already taken care of the above load

ability limits in deciding the Zone-3 settings. STUs were requested to furnish the data regarding

Zone – III settings in respect of intra-state lines requiring relay coordination with CTU network

directly to CTU under intimation to WRPC.

6.2 : Discussions :

EE(P) stated that POWERGRID representative in 120th PCM informed that the revised zone –

3 distance protection settings of few interstate/interregional lines were not received from

constituents. CTU was requested to forward the list of lines to WR constituents and

constituents were requested to furnish the relevant data in this regard at the earliest.

21  

POWERGRID representative stated that the data has been received.

Committee noted.

Item No 7: Commissioning of new system protection schemes in connection with

synchronization of SR and NEW grid

7.1 : Back ground :

The activities associated with the synchronization are being periodically monitored by the

Central Electricity Authority and the Ministry of Power. Commissioning of certain identified

System Protection Schemes is one of the prerequisites for synchronization. The details of the

SPS to be implemented in Western Region and the actions to be taken by different utilities were

elaborated vide WRPC letter WRPC/Protection/SPS/2013/2046 dated 29.11.2013 to all the

concerned. Concerns were raised by the constituents of WR pertaining to overloading in Vapi-

Boisar sections, Wardha and Raipur flow gate flows, voltage conditions in Solapur area and

other prevalent conditions likely to change after the synchronization. Constituents opined that

matters pertaining to the SPS, Bhadravati HVDC Frequency Controller settings etc. requires the

involvement of NLDC in the discussion.

A meeting was held on 17.12.2013 at WRLDC. Minutes of the meeting held on 17.12.2013 are

available on WRPC website. All utilities extended their support in implementation of relevant

SPS in short duration and helped the process of SR grid synchronization with NEW grid.

Concerns regarding the backing down quantum and inclusion of more generators in the backing

down of generations under various schemes were raised by the WR constituents in the 120th

PCM and 25th WRPC meetings. Accordingly WRPC vide letter dated 25.02.14 (enclosed at

Annexure-7.1) took up the issue with NLDC including other technicalities involved in the

schemes. NLDC vide letter dated 11.04.2014 (Annexure-7.2), forwarded the revised proposal

for various SPS related with 765kV Solapur-Raichur circuit. A meeting was held on 29.04.2014

to discuss the above proposal and the backing down quantum for generators in WR finalized

for various security threats in the meeting is enclosed at Annexure-7.3.

7.2 : Discussions :

Member Secretary stated that since arrangement of the communication signals to the additional

generators in WR included in the SPS for backing down of generation would take some time,

till such time the logic and enhancement of triggering criterions could be implemented

22  

immediately, wherever the backing down quantum by WR generators in the implemented SPS

and revised SPS is same.

EE(P) WRPC stated that in case of SPS-1 the quantum of backing down has been increased

from 500MW to 800MW, since two generators(JPL & KSK) were identified for 500MW, the

SPS-1 flow limits shall be kept as 800MW for 2.5sec and 1000MW instantaneous instead of

1000MW for 2.5sec and 1500MW instantaneous as suggested in the revised SPS with backing

down of 500MW at JPL(350MW) & KSK(150MW).

For SPS -8 and 9 backing down quantum’s suggested in revised scheme is 800MW as against

implemented 500MW, however the triggering criterion has been kept the same, hence the

backing down quantum of 500MW can be retained.

In other SPSs (SPS-2 to 7), the backing down quantum suggested is equal to or less than earlier

suggested quantum’s, therefore the increase in flow limits and delays can be incorporated

immediately. The Table for immediate implementation is enclosed at Annexure-7.4.

Members agreed for the same. The Table for immediate implementation is enclosed at

Annexure-7.4.

 

ITEM NO 8: Report on Grid disturbance at CGPL/GETCO system on 12.03.2014:

8.1 : Back ground :

Two separate events occurred at about 1910 and 1921 hrs on 12.03.2014 at 400 kV Chorania

s/s. During the latter event there was tripping of all the CGPL running units. The grid also

experienced a large drop in frequency.

EE(P) stated that Special meetings were held on 19.03.2014 and 21.03.2014 at WRLDC,

Mumbai and CGPL Mundra respectively to discuss and analyze the occurrence of 12.03.2014

in the GETCO/CGPL system. Based on the discussion and data submitted for analysis, a report

was prepared and is available at www.wrpc.nic.in.

The following recommendations pertaining to protection system were made;

i) Operation of LBB of 400kV Chorania-Kosamba line No. 1: It is recommended that

during fire, all the control wiring fuses of the control panel of the affected element/bay should

be removed immediately so as to avoid leakages in damaged cable cores. The immediate

resetting of the tripped relays is not possible under such circumstances, since the S/S officials

are generally busy controlling the fire.

23  

ii) Load Relief Related: It was recommended that since UMPPs and large generating

stations are located in Gujarat and Chattisgarh States more quantum of load shedding should be

wired up through df/dt relays in Gujarat and Chattisgarh State. Further the rate of df/dt in

Gujarat system for the first stage is set at 0.2Hz/sec, therefore Gujarat should explore to set the

first stage at 0.1Hz/sec.

iii) Tripping of lines in Z-1 power swing: After the operation of LBB protection the

evacuation from CGPL got depleted and resulted in setting up of power swings in the system.

The lines connected to CGPL Mundra subsequently tripped in Z-1 (400 kV Bachau-CGPL-1 at

Bhachau end, 400 kV Bachau-CGPL-2 at Bhachau end, 400 kV Jetpur-CGPL-1 at Jetpur end,

400 kV Jetpur-CGPL-2 at Jetpur end, 400 kV Bachau-Ranchodpura-1 tripped at Bhachau end,

220kV Bhachau-Lalpar & Bhachau-Morbi lines at Bhachau end due to the power swing, before

the generators at CGPL Mundra fell out of synchronism (even before the first pole slip) with

the rest of the grid generators. As per the existing protection philosophy power swings entering

in Z-2 & Z-3 are blocked and power swings entering in Z-1 of DPS are allowed to trip the line

due to the severe nature of power swings entering in the Zone-1. Therefore Z-1 philosophy

adopted for tripping the lines in Z-1, connected to the generating stations and lines nearby the

vicinity of generating stations which are supposed to power swings needs to be discussed in the

PCM. Under such circumstances the possibility of using out of step protection relay as an

alternative to tripping a line in Z-1 power swing requires to be deliberated in the PCM. This

incidentally has also been raised by the Hon’ble commission CERC in its order on the grid

disturbances of 30th & 31st July 2012.

iv) GPS Synchronization: The time stampings on the DRs generated during the above

occurrence did not coincide and there was quite a large time drift. GPS time synchronization of

the relays shall be carried out. The methodology/procedure for carrying out the synchronization

may be discussed in the PCM.

v) PMU Wiring up at CGPL: The PMU data was not sufficient to analyze the

occurrence. Instead of wiring the current input of Unit#40 of the CGPL, line currents of

Bhachau lines would have been more useful.

vi) Proposed Changes in SPS at CGPL Mundra : This is given at Item 9.3.

8.2 : Discussions :

CGPL representative briefly appraised the committee of the disturbance occurred on

12.03.2014 at CGPL/GETCO system. The details are enclosed at Annex-8.0.

24  

Shri S.G.Patki, TPC informed that as regards to recommendation at (iii) above, the task force

has given its recommendation and it has been suggested to carry out extensive studies to

ascertain corridors/tie lines where power swings would take place and identify locations where

separation under such power swings could be carried out by blocking the distance protection

for all the zones. However the task force has recommended blocking of Z-II & Z-III under

power swings and allow tripping in Z-I, due to severe nature of the power swing for all lines

(till corridors/tie lines are identified, after identification of such lines the OST protection on

these lines can be enabled by blocking all the zones for power swing).

EE(P) WRPC pointed out that during the above occurrence there was no fault in the system

and five 400kV lines tripped from remote ends on Z-I power swing after depletion of partial

network. The tripping of these lines led to complete depletion of evacuation for CGPL Mundra

and therefore it was felt to initiate discussion on as to whether Z-I can also be blocked for lines

originating from generating stations, since OST protection is available for units at generating

station.

Shri S.G.Patki stated that, since there was no fault during the above occurrence and the

tripping of remaining lines in Z-I power swing makes it an interesting case and further

investigation through studies could be undertaken.

As regards to GPS Synchronization, it was suggested that since all the utilities are

required to synchronise the relays/ERs with GPS clock, they should adhere to this strictly.

Further whenever there is disturbance/tripping of line the time stampings of the DR/ER

shall be intimated by the utilities concerned to SLDCs/WRLDC so that it could be

ascertained by SLDCs/WRLDC that the time stampings are correct and synchronized

with GPS.

ITEM NO 9: IMPLEMENTATION STATUS OF SPS UNDER PROGRESS:

9.1) SPS for 765 kV Gwalior-Agra D/C (Generation Run back Scheme in WR): An SPS

was envisaged for ensuring backing down WR generation by 500 MW (VSTPS - 200 MW,

KSTPS - 120 MW, CGPL - 180 MW) in case of sudden reduction of NR import from WR on

Bina-Gwalior-Agra link by 1500 MW.

The above scheme was tested on 21.03.2014 and put into service subsequently.

Committee noted.

9.2) SPS at APL Tiroda : A special meeting was convened by WRPC to review the SPS at

APL Tiroda post commissioning of both the 400 kV Warora- Chandrapur (II) lines and LILO

of Chandrapur-Parli at Chandrapur-II on 19.02.2014.

25  

Following logic for SPS was accepted.

1 Schemes based on Wardha

Flow Gate

It was decided to deactivate all schemes based on

Wardha flow gate

2 When one 400 kV

Chandrapur(II)-Warora

trips:

it was accepted that the generation at APML will be

backed down

automatically to the level of 1500MW (When three units

are available) so that some automatic generation backing

down is there and further backing down if required will

be advised by SLDC, Kalwa on real time basis.

3 When both the 400 kV

Chandrapur(II)-Warora

Lines trips:

one unit at Tirora will be tripped if three units are

running. If two units are running, then there is no

tripping. In both these cases, further backing down

required, if any, will be advised by SLDC, Kalwa on real

time basis.

4 Line overloading based

schemes for 400kV Tiroda-

Warora and Warora

Wardha Lines are in service as instructed by SLDC,

Kalwa. It was decided the automatic portion of 400 kC

Warora-Wardha portion may be removed, due to the

configuration changes

5 NLDC scheme: Backing down 600 MW in case of over loading of any of

Wardha-Parli lines beyond 750 MW (This scheme was

put into service as envisaged by NLDC for SR-NEW

grid synchronous operation).

Member Secretary stated that since transmission system around APL Tiroda would change in

the near future, therefore a separate meeting would be held to discuss the modification in the

above SPS.

Committee noted.

9.3) SPS for CGPL units:

Back ground :

The scheme as agreed in the 24th WRPC meeting held on 09.10.2013 at Goa is as follows

26  

TABLE : A - SPS for CGPL CGPL Gen (MWs) Chorania-1Chorania-2 Bhachau-1 Bhachau-2

Jetpur-1 & 2 line Loading in MW Action at CGPL

1 >3100 X X >1500 Trip mills this will reduce generation by @500MW except for condition 2 where units would trip

2 >3100 X X >1500 3 >3100 X X >1500 4 >3100 X X >1500 5 >3100 X X >1500 6 >3100 X X >1500 7 >3100 >1200 Alarm for reduction in

generation so that the Jetpur lines loadings are maintained around 1200 MW

X- indicates tripping of the line.

In the 120th PCM, GETCO representative stated that Bhachau – Vadavi lines are extension of

CGPL – Bhachau lines, therefore, tripping of Bhachau – Vadavi line needs to be incorporated

in the above SPS.

The SPS was reviewed during the meetings held on 19.03.2014 and 21.03.2014 at WRLDC to

discuss and analyze the disturbance occurred at CGPL/GETCO system on 12.03.2014. The SPS

for immediate implementation is as follows:

TABLE : B –SPS for immediate implementation for CGPL

CGPL Gen in MW Chorania- Chorania-

Bhachau-1 Or

Bhachau- Ranchodpura

1 or 2 Line

Bhachau-2 Or

Bhachau- Ranchodpura

1 or 2 Line Jetpur-1 & 2 lineLoading in MW Action at CGPL

1 >3100 X X >1500

Trip mills this will reduce generatio@500MW, except for condition 2 wh

unit would trip

2 >3100 X X >1500

3 >3100 X X >1500

4 >3100 X X >1500

5 >3100 X X >1500 6

>3100 X X >1500 7 >3100 >1200 Alarm for reduction in generation so

the Jetpur lines loadings are maintaiaround 1200MW

X- indicates tripping of the line.

Following options for the SPS post occurrence of 12.03.2014 were suggested in the above

meetings;

The existing SPS may be replaced by

Option-A :

27  

(i) If line loading on any line exceeds 900MW back down generation at CGPL.

(ii) If line loading on any line exceeds 1200MW trip one unit at CGPL.

Option-B :

(i) For loss of any two lines trip one unit at CGPL.

(ii) For further loss of any two lines trip another unit at CGPL.

CGPL was requested to intimate their views on the above SPS. CGPL vide letter dated

29.03.2014 (Annexure – 9.3) have forwarded their comments on the above and intimated that

the following option is agreeable to them.

(i) If export is more than 3100MW and any one line out of six lines trip –reduce

generation in two units to the tune of 800MW.

(ii) If second line trips immediately in addition to (i) –further reduce generation in other

two units to the tune of 800MW.

Discussions :

WRLDC/SLDC representatives as regards to case (ii) suggested by CGPL, stated that they do

not agree for backing down of generation since the relief would be slow, therefore one unit

should be tripped for case(ii) when the on bar generation at CGPL is greater than

3500MW.Also in case(i) instead of six lines it should be eight lines, since 400kV Bacchau-

Ranchodpura ckt 1 & 2 needs also be considered.

CGPL representative stated that in the interest of grid they are ready for the suggestions,

however simulation studies should be carried out and shared with CGPL.

Member Secretary stated that under normal circumstances immediate tripping of second line is

a rare possibility, therefore CGPL should agree for the suggestion of SLDC/WRLDC in the

interest of grid security and survival of its own generating units. The studies can be carried out

and shared with CGPL by WRLDC in due course.

CGPL representative agreed for the scheme in the interest of grid, however insisted that studies

should be carried out by WRLDC and shared with CGPL.

Therefore the scheme agreed is as follows;

(i) If export is more than 3500MW and any one line out of eight lines trip –reduce

generation in two units to the tune of 800MW.

(ii) If second line trips immediately in addition to (i) –trip one unit immediately.

28  

9.4 Proposed SPS/Islanding scheme: 9.4.1) SPS for reliable evacuation of Sipat generation : Back ground : The SPS was discussed in the special meeting held on 03.09.2013 at TAPS 3 & 4 wherein

NTPC representative made a presentation on the SPS.

The group suggested that instead of tripping of 660MW, NTPC may explore other options such

as HP/LP bypass so that the unit is not tripped/stressed unnecessarily. NTPC representative

informed that they would revert after ascertaining the effectiveness of HP/LP bypass system.

The group suggested that PCGIL would provide potential free signal at Sipat NTPC & ACIBL

and necessary telemetry data of line flows. WRLDC representative stated that backing down of

generation through HP/LP bypass would be a slow process and would result in overloading of

the ICTs. They would give their requirement to NTPC Sipat. It was informed that ICTs can be

loaded more than the rated capacity for 5-10mins depending on the ambient temperature

subject to temperature rise of oil within permissible limits.

The proposal for SPS at NTPC Sipat was discussed and examined by WRPC & WRLDC in a

meeting held on 18.03.2014 and following was decided:

a) If the Ex-bus generation at Sipat is more than 2200MW (which is 110% of the rated

capacity of both the ICTs) and both the 765kV Sipat-Bilaspur lines or 765kV Bilaspur-Seoni

lines trips, NTPC shall back down generation quantum equal to (Ex Bus Generation-

2200MWs) automatically. Appropriate unit selection at NTPC Sipat may be decided by NTPC.

b) Even after backing down the above quantum at “a”, the loading on ICTs is above

100%, NTPC shall manually back down/trip the generation, so that the loading on both the

ICTs is acceptable.

NTPC representative stated that they have received the approval for the above scheme

from their HQ and would be put into service shortly.

Committee noted.

9.4.2) : SPS at 4x300 MW Balco IPP :

Back ground : In the 454th OCC meeting it was intimated that the SPS at Balco was scheduled

for commissioning by Nov 2013 after commissioning of first unit of 4x300 MW Balco IPP. It

was also reported that as a consequence of disconnection from Chhattisgarh, a revised islanding

scheme would be in place at Balco. Further as per MOM of 17th meeting of WR regarding

29  

connectivity/OA applications held on 03.01.13, Balco was asked to implement SPS to trip

selected units from 4x135MW in case of load throw off of Aluminum refinery load. It was

suggested that NTPC, Balco & PGCIL meet together to device suitable scheme & implement at

the earliest.

Discussion :

WRLDC representative stated that the SPS has been put into service.

Committee noted.

9.5: Islanding schemes for Nuclear Power Stations:

9.5.1) KAPS : In pursuance with the decision in the special meeting held on 03.09.2013 at

TAPS 3 & 4, SLDC GETCO and KAPS have formulated the islanding for KAPS.

KAPS representative briefly explained the scheme. The salient features are as follows

1. One unit of KAPP(220MW) would be selected for island operation and the other

unit would go on house load, considering the safety requirements for Nuclear units. The

unit whose governor action is good would be identified for islanding with Vapi load. Ex-

bus generation of the unit is in the order of 190-200MW. The reactor controller would

be switched off and only frequency controller of the unit would be in service to take care

of the load generation balance in the island.

2. Stage-I 48.6 Hz (inst.)- Trip 66kV Dabhel, 66kV Kacchigam, 66kV Morai &

66kV Damanganga at Vapi S/s

Stage-II 48.4 Hz, (with 0.2 Sec time delay)- Trip all 220kV breakers at Vapi

except KAPS feeders.

Stage-III 48.2Hz (inst.) – Trip all 220kV feeders except Vapi feedrs ar KAPS.

Unit selected for Island mode will feed Vapi load.

Unit selected for House load will operate under house

Load.

Stage-IV 48.0Hz Island freq. (inst.) – Additional losd shedding by tripping 66kV

GIDC feeder at Vapi S/S.

Stage-V 47.7Hz Island freq (0.2sec delay) Station load transfer to UT & TG CB

trip for putting the island unit under house load.

The above scheme was discussed and it was suggested that the frequency during grid

disturbance would fall rapidly and it would not remain static for the delays suggested.

30  

Therefore frequency fall and the time delays should be appropriately selected. The

following was suggested and agreed by PCM;

Stage-I 48.6 Hz (inst.)- Trip 66kV Dabhel, 66kV Kacchigam, 66kV Morai & 66kV

Damanganga at Vapi S/s

Stage-II 48.4 Hz, (with 0.4 Sec time delay)- Trip all 220kV breakers at Vapi except

KAPS feeders.

Stage-III 48.2Hz (0.5 sec time delay) – Trip all 220kV feeders except Vapi

feeders ar KAPS.

Unit selected for Island mode will feed Vapi load.

Unit selected for House load will operate under house

Load.

Stage-IV 47.8Hz Island freq. (0.5 sec time delay.) – Additional load shedding by

tripping 66kV GIDC feeder at Vapi S/S.

Stage-V 47.5Hz Island freq (0.8 sec time delay) Station load transfer to UT &

TG CB trip for putting the island unit under house load.

KAPS representative informed that main under frequency relay (MICOM-P-941 numerical

relay) would be purchased by KAPS for Vapi Sub-station, since the existing FCX relay is

defective. Other auxiliary relay procurement and wiring might be carried out by GETCO.

GETCO agreed for the same.

GETCO representative stated that they have planned for PLC based islanding scheme and in

near future the same would be incorporated in the Islanding scheme.

The approved Islanding scheme by the Committee for KAPS is enclosed at Annex-9.5.1.

9.5.2): TAPS 1&2 Islanding:

Back ground :

The formulation of islanding scheme for TAPS 1 & 2 was discussed in the special meeting held

on 03.09.2013 at TAPS 3 & 4.

The group suggested following;

31  

a) TAPS 1 & 2 islanding with Boisar load was discussed. However due to fluctuating load at

Boisar (MSETCL) MIDC load it did not seem feasible, since fine generation control is not

available at TAPS 1 &2.

b) In view of above ‘a’ it was suggested to isolate TAPS 1 &2 from MSETCL at higher

frequency as a preparedness to islanding and would remain with GETCO system (i.e. Vapi-

Bhilad). Subsequently TAPS 3 &4 islanding with Boisar load may be thought of.

c)WRLDC would prepare a scheme of isolation points and logic in consultation with GETCO,

MSETCL & TAPS.

d) The details of the settings would be worked out by WRLDC in consultation with GETCO,

MSETCL & TAPS.

Discussion:

WRLDC representative stated that they would shortly convene a meeting as suggested

above.

Committee noted. 9.5.3) TAPS 3&4 Islanding:

The formulation of islanding scheme for TAPS 3 & 4 was discussed in the special meeting

held on 03.09.2013 at TAPS 3 & 4.

The group suggested following;

a) TAPS 3 & 4 one unit to island with Boisar load and other unit to island with house load.

b) WRLDC would prepare the details of the islanding scheme in consultation with GETCO,

MSETCL & TAPS.

c) The details of the settings would be worked out by WRLDC in consultation with GETCO,

MSETCL & TAPS.

Discussion:

WRLDC representative stated that they would shortly convene a meeting as suggested

above.

Committee noted. 9.5.4) Sugen Islanding:

32  

The formulation of islanding scheme for Sugen TPP was discussed in the special meeting held

on 03.09.2013 at TAPS 3 & 4.

The group suggested following:

a) Isolation of feed from 220 kV Kim – Sugen may be opened at higher frequency 48.2 Hz as a

preparation to islanding.

b) PLC based load trimming to be implemented to match generation at Sugen, exact settings

can be decided later.

Discussion:

GETCO representative stated that they would finalize the islanding scheme on the lines

suggested above.

Committee noted. ITEM NO. 10: Follow up items:

10.1: AUFLS Quantum & Stages

A. Back ground: In the 2nd NPC meeting held on 16.07.2013 at Delhi, four (4) stages of

automatic under frequency relay operation starting from 49.2 has been approved.

CEA vide letter No.8/X/MMS/Gm-13/1007-1012 dated 06.08.2013, have intimated that while

the process for complete implementation of UFR based load shedding may be continued so as

to complete the same within three months, the frequency stages of 49.2 and 49.0 Hz with

required load reliefs may be implemented by all the concerned utilities within a fortnight’s time

by raising the frequency settings of the existing under frequency relays suitably and compliance

of the same may please be communicated to this office by 25th August 2013. The

implementation of load shedding for all the four stages (i.e. 49.2, 49.0, 48.8 and 48.6Hz.) be

taken up subsequently and completed by 22.10.2013.

In the 24th WRPC meeting the status was up dated as follows;

1. First two stages of AULFS setting have been already implemented by all the WR

constituents.

2. Gujarat informed that they have implemented all the four stages.

3. Other Constituents agreed for implementation of other two stages by March 2014, as

procurement of UFR relays is also on going.

The status on implementation of the AUFLS was reviewed in the meeting held on 17.12.2013

at WRLDC Mumbai. The status updated as on 15.12.2013 is as follows.

33  

AUFLS implementation status in WR as on 15.12.2013 (All figures in MWs) 49.2Hz 49.0Hz 48.8Hz 48.6Hz

Actual Target Actual Target Actual Target Actual Target Gujarat Avg. 773 580 726 580 1117 580 1025 590

Peak MP Avg. 468 460 450 460 460 460 465 465

Peak Chattisgarh Avg. 110 150 114 150 117 155 91 155

Peak Maharashtra Avg. 1108 805 1200 810 765 815 851 820

Peak Goa Avg. 25 25 25 25

Peak DD Avg. 10 15 15 15

Peak DNH Avg. 30 30 35 35

Peak TOTAL Avg. 2459 2060 2490 2070 2459 2085 2432 2105

Peak

In the 120th PCM, the sub-Committee appreciated MSETCL, GETCO, MPPTCL and CSPTCL

for implementation of 4 stage AUFLS but also expressed concern about GOA, DD & DNH

since status from these utilities is still awaited. GOA, DD & DNH was requested to expedite

the procurement process of the UFRs and update the status.

All the constituents were requested to give the list of the feeders with UFRs in a soft copy

(excel sheet) within 15 days along with other details like peak load (MWs), average load

(MWs), kV, substation etc., It was also requested utilities to furnish the details of df/dt relays to

WRPC in soft copy.

MSETCL, GETCO, MP & Chattisgarh have submitted the data for UFR relays. UFR data from

DD, DNH & Goa is still not received. None of the utilities have submitted data for df/dt relays.

Committee noted that the target for overall quantum of load relief in WR has been

achieved. However, Committee observed that DD, DNH & Goa should implement the

AUFLS targets at the earliest and the details of UFR feeders, as above shall be forwarded

by constituents to WRPC/WRLDC for compilation and ready reference.

34  

10.2) Over-Voltage Protection for Transmission lines in Western Region

Back ground: WRLDC vide letter WRLDC/MO-I/1658/2012/8960 dtd. 15.05.2013 have

intimated that, considerable number of critical 765/400 kV lines are being kept out for

containing High voltage. Also there are several cases of multiple tripping of feeders emanating

from a single node on over voltage. Multiple tripping on O/V at one node or in a single corridor

may lead to transmission depletion adversely affecting grid security. In such cases the drop off

to pick ratio should be increased to 99% while the over-voltage rating should be changed to 112

% to increase the reliability of the grid. The high drop-off to pick-up ratio of the O/V relays

(say 99% and above) ensure quick reset of the relay so as to avoid multiple tripping of feeders

on over voltage.

• For a standalone static type of relay the drop-off to pick-up ratio may be relooked and

modified to 99% at all locations in WR grid by the respective utilities / constituents.

• In case the relay is of multi-function numerical type where the over voltage function is being

utilized for O/V protection the vendor may be requested by the concerned utility to modify the

ratio (drop-off to pick up) to 99%.

Following nodes in western region are identified as high voltage node where lines trip on over

voltage protection: Chandrapur, Parli, Raigarh, Raipur, Wardha, Indirasagar, Kolhapur,

Solapur, Karad, Rajgarh, Khandwa, Itarsi, Dhule, Seoni, Nagda, Kasor, Bhadrawati, Akola.

The matter was discussed at length in the 117th, 118th & 119th PCM. a) It was informed that the maximum continuous rating of the equipments in the system

is around 5% above the nominal voltage (i.e. 420kV). Further the drop off to pick up ratio

hysteresis is set not just to inhibit the relay from operating but while deciding the hysteresis

following factors are required to be considered;

(i) The basic insulation level on which the system equipments are designed.

(ii) Time to settle down the system voltages.

(iii) Tripping of breakers around the safe voltage limits.

Therefore adopting the setting of drop off to pick up ratio to 99%, would ensure that the line

would trip (breaker opening) above 435kV, which is dangerous.

Committee felt that the drop off to pick up ratio be set around 97%.

b) Protection sub-Committee suggested the following remedial measures;

1. The overvoltage trip setting shall be graded for magnitude and time at the nodes where

sustained over voltage above nominal voltage is observed by the utilities and the settings

35  

adopted be communicated to WRPC. The time delayed overvoltage trip setting shall not exceed

110%.

2. Manual control for overvoltage shall start at 415kV and manual opening of lines on

overvoltage should stop at 430kV.

3. WRLDC would carry out operation studies to identify over voltage nodes for manual

control at 415kV, 420kV, 425kV and 430kV.

4. WRLDC would carry out operation studies for time co-ordination of over voltage

settings.

5. In addition to the lines already identified for over voltage tripping some more lines

need to be identified in consultation with utilities as in present scenario after exhausting MVAR

absorption by generator, line opening is only the option left to operator to contain high voltage.

6. The tap changing is an operational issue and generators should set the tap(off-line) as

suggested by WRLDC during opportunistic shut downs. Tap setting shall only be suggested

seasonally. Committee suggested manual action to control the voltage should start from 105 %

and auto line trip on over voltage should start from 106 % with appropriate voltage and time

grading. The committee requested WRLDC to identify high voltage nodes and lines need to be

tripped in a co-ordinated manner.

In the 120th PCM, the sub-Committee requested utilities to furnish the O/V relay settings of

lines in their system to WRPC and WRLDC by 15.01.2014. WRPC and WRLDC would then

review the existing settings and revised over voltage settings (magnitude and time graded)

would then be intimated to utilities for implementing the same. However, utilities may

implement/continue with the settings adopted, till review is done at WRLDC/WRPC.

GETCO, MP, POWERGRID –I & II, Maharashtra, APL & CGPL have submitted the data.

Data of some lines in respect of NTPC & Chattisgarh is not received. Data from IPPs & NHDC

is still awaited.

EE(P) stated that NTPC, Chattisgarh and IPPs (India Bulls, IEPL, JPL, JP Bina etc) may

forward the data at the earliest. Further the consolidated list of lines with O/V setting was

attached at Annex – 10.2 of the Agenda and there is ambiguity in respect of settings marked in

red color of the list, therefore Utilities may verify the same and forward correct settings.

Member Secretary queried whether there are any guide lines for O/V settings to be adopted for

765kV lines, the O/V settings adopted for 765kV lines by POWERGRID is 107 to 109% of

nominal voltage and therefore committee may suggest suitable settings.

Shri S.G.Patki stated that the issue has been addressed in the Protection subcommittee

report titled “Model setting calculation documents for typical IEDs used for the protection

36  

of different power system elements in 220kV, 400kV and 765 kV substations” and the

settings suggested are as follows;

Low set stage (Stage-I) may be set in the range of 106% - 109% (typically 108%) with a

time delay of 5 seconds.

High set stage (Stage-II) may be set in the range 140% - 150% with a time delay of

100milliseconds.

Committee noted. 10.3: Status of Bus Coupler and Bus Bar protections at S/s

Back Ground:

In the 118th PCM, Chairman TCC stated that the Bus Bar protection schemes should be

provided by the respective utility at the earliest, without expecting funding under R&U from

MoP, GoI.

In the 120th PCM it was informed that BB protection at 7Nos of 220kV S/Ss (Single Bus S/Ss)

in GETCO system, 3Nos of 220kV S/Ss in MSPGCL system, 7Nos of 220kV S/Ss in

MPPTCL system & 5Nos of 220kV S/Ss in CSPTCL system was pending.

Committee felt that the BB protection schemes should be commissioned at the earliest.

10.4: Time synchronization, non-working of DR & Main-2 of Ranchodpura line-2 at

Dehgam S/s:

Back Ground: PGCIL vide letter WRTS II/O&M/273/AV/1211 dated 30.03.2013 &

WRTS/DEH/SS/385/113 dtd. 28.01.2012, have intimated that the pending protection issues

related with GETCO bays at Dehgam S/S have not been attended so far and requested GETCO

for configuration of DR for Main-1/Main-2 protection along with wiring of digital inputs &

GPS time synchronization.

In the 120th PCM GETCO representative informed the above would be rectified by January –

2014.

GETCO representative informed the wiring has been completed.

Committee noted.

37  

10.5) NGR bypass scheme of line reactor to convert it as bus reactor in State owned

transmission lines.

Back Ground:

10.5.1: Many 400 kV nodes in WR are experiencing high voltages. Several lines are kept open

to control the high voltage in Western region. The line reactors of these lines are available for

taking them in to service as bus reactors. PGCIL has commissioned the NGR bypass scheme to

convert the line reactor as bus rector for most of the lines in WR-I and WR-II. Other

constituents are also requested to expedite the same to use the line reactor as bus reactor

wherever such line reactors are available. This will help in controlling the high voltage scenario

in Western region.

10.5.2: In the 119th PCM, Committee felt that, whenever line along with its reactor is out of

service and wherever NGR bypass scheme is available, the line reactor should be used as a bus

reactor. However this is possible only if NGR bypass scheme is already installed on the line

reactors. The need for NGR bypass requirement was also discussed and it was decided that the

STUs would explore providing the NGR bypass scheme wherever possible (especially at high

voltage nodes). WRLDC was requested to forward the list of lines where line reactors are

required to be converted to Bus reactors.

POWERGRID vide letter No WRTS II/O&M/250/1447-4656 dtd 27.11.2013 have updated the

status on implementation of NGR bypass schemes implemented in WR-II of POWERGRID.

10.5.3: It was intimated that the line reactors can be converted and used as Bus reactors only if

the S/Ss have one and a half Bus Bar System and the line reactors are connected to the Bus

side. WRLDC have forwarded list of where line reactors are required to be converted into bus

reactors in order to control the over voltage in the system. Committee requested utilities to

check the above implementation feasibility and intimate WRPC at the earliest.

MP representative stated that line reactor to Bus reactor conversion at Nagda end of

400kV Nagda-Rajgarh-II has been carried out on 14th March 2014, through CSR.

Committee noted.

ITEM NO. 11: Date and Venue of the next meeting

It was decided that the next (122nd) PCM would be held in Sept. 2014.

*********

Annex-1

Sl.No. Organisation & Name Designation E-mail Mobile No.

WRPC1 Shri S.D. Taksande M.S. ms-wrpc@nic.in 98208783842 Shri P.D.Lone E E pramod.lone@gmail.com 9867622823

MSETCL/MSPGCL3 Shri S.G. Kashikar Dy.C.E. sanjay_kash30@yahoo.co.in 98819609304 Shri A.V. Deo S E adwaitdeo@hotmail.com 85549932905 Shri S.S. Rajurkar S E se1om@mahatransco.in 97695090206 Mrs S.S. Kumbhai S E se3500@mahatransco.in 84110014317 Shri P.M. Deshpande E E ee1150@mahatransco.in 85549894808 Shri P.S. Sharma E E ee7250@mahatransco.in 97692138659 Shri Ashok K. Dhapare E E ee3150@mahatransco.in 841100909610 Shri Bharamgunde C.L. Dy. E E dyee13500@mahatransco.in 841100156211 Dy. E E ndp1210@rediffmail.com 9769509798

MPPGCL/MPPTCL12 Shri P.C. Soni S.E. cedesign_mpeb@yahoo.com 942580655213 Shri Sunil Yadav E E setindore@yahoo.com 942580491614 Shri R.C. Sharma E E eesubldcind@yahoo.com 9425804970

GETCO15 Shri B.B. Mehta C E bbm@gebmail.com 987920073616 Shri J.N. Pancholi OSD janaknpancholi@yahoo.com 997893614517 Shri Nirav G. Barot J E jetesting.getco@gebmail.com 992521398218 Shri K.G. Patel D E det.gsecl@gebmail.com 9925210977

D & N H19 Shri Hasmukh M. Rohit J E trans.dnh@gmail.com 9925288811

WRLDC / POWERGRID20 Shri K.S. Devaprasad D G M ksdp97@gmail.com 986948390421 Shri Abhimanyu Gartia D G M agartia@gmail.com 986908805822 Shri Anand Dubey C M anand.dubey_pg@rediffmail.com 942850406523 Shri Kuleshwar Sahu C M kuleshwars@gmail.com 942529421424 Shri Vaibhav Bhandarkar Mgr. vbhandarkar@powergridindia.com 942230312925 Shri Chandan Kumar Eng. protectionwrldc@gmail.com 986925146026 Shri Awani Bhushan Rai Eng. raiawani@yahoo.co.in 9869414293

NTPC27 Shri D.Roy Chowdhury A. G. M. drc85@rediffmail.com 9425222094

NPCIL 28 Shri N.S. Patil Sr Tech Engr. nspatil@npcil.co.in 942882184429 Shri Nayan Shah SO/D nvshah@npcil.co.in 9420881419

Tata Power

LIST OF PARTICIPANTS OF 121st PCM MEETING HELD ON 15.05.2014 AT Tata Power, Mumbai

30 Shri T. Murali Krishna A G M tmurali@tatapower.com 922332750131 Shri M.V. Kini D.G.M. mvkini@tatapower.com 922332114032 Shri Alok Uppal C Mgr. uppalalok@tatapower.com 909900643033 Shri Girish Jawale Sr. Mgr. gtjawale@tatapower.com 922331141934 Shri K.N. Athavale Head-EMD knathavale@tatapower 922729535835 Miss. Shraddha Maharkar Lead-Eng shraddha.maharkar@tatapower.com 9893160273

NSPCL36 Shri Rakesh Sharma Suptd. sharmarakesh1@rediffmail.com 9425293323

Torrent Power 37 Shri M.J. Modi Mgr. milindmodi@torrentpower.com 9227233328

APL38 Shri Ravidutt Sharma Asso. Mgr. ravidutts.sharma@adani.com 9687660612

6/13/2014

1

On 15th JAN 2014 at @09:39 Hrs.,’R’ ph CT of 220kv Mudshingi-Karad ckt.- 4 bursted thus leading to Operation of 220 KV Bus bar protn. at 220 KV Mudshingi S/stn.The following are Window & Relay Indications at time fof occurrence

6/13/2014

2

Sr. No. Name of feeder /TF Window Indication Relay Indication Tripping

Date & TimeRestoration Date & Time

Load Affected

1 220 KV Karad-IV

L.End-Distance Protection Optd.R.End-Dist.Prot

optd.

L.End- R ph, Zone 1, Dist = -1.9 km. Fault currents -R - 11.8 kA, Y - 1.71 kA, B - 0.53 kA, E - 12.5 kAR.End-R-Ph trip,R,Y,B Ph,Z-2,Z3 trip, Dist 75km, Fault current-R-1649A,Y-383.6A,B-514.3A,E-746.3A.

15.01.2014 09:39 15.01.2014

22:35

2 220 KV TBC Bus Bar Protection Operated.

RCS 915 - BFP trip, BBP trip BB1, BBP trip BB2, BBP trip BB3, 96 relay of all 220 KV bays

15.01.2014 09:39

15.01.2014 10:17

15 01 2014 15 01 2014

Load affected 189 MW for 0.38 Hrs,totalKolhapur District.

3 220 KV Peth NIL

Bus Bar trip relay 96 operated.

15.01.2014 09:39

15.01.2014 10:17

4 220 KV Karad II NIL 15.01.2014 09:39

15.01.2014 10:17

5 220 KV Talandage Ckt I NIL15.01.2014

09:3915.01.2014

10:17

6 220 KV Talandage Ckt II NIL15.01.2014

09:3915.01.2014

10:17

7 220 KV Mumewadi NIL 15.01.2014 09:39

15.01.2014 10:17

8 220 KV Chikodi NIL 15.01.2014 09:39

15.01.2014 14:18

15 01 2014 15 01 20149 VEL, 200 MVA ICT- I NIL

15.01.2014 09:39

15.01.2014 10:20

10 VEL, 200 MVA ICT- II NIL15.01.2014

09:3915.01.2014

10:20

11 VEL, 200 MVA ICT- III NIL15.01.2014

09:3915.01.2014

10:20

12 BBL, 50 MVA T/F NIL15.01.2014

09:3915.01.2014

10:19

13 CGL, 50 MVA T/F NIL15.01.2014

09:3915.01.2014

10:19

14 220 KV WatharL.End-NIL

R.End-Dist. Prot. Optd

L.End-96 relay operatedR.End-General trip, B-Ph trip, Z-3 trip,

15.01.2014 09:39

15.01.2014 14:05

Sr. No.

Name of feeder /TF

Window Indication Relay Indication Tripping

Date & TimeRestoration Date & Time Load Affected

1. 400KV Karad RS

220KV Kini Wathar

L.End- Dist Protn. Optd, C.B lockout.R.End-No tripping.

L.End-Trip, B Ph, Z-3. IR-582A, IY-353A, IB-1339AR.End-No tripping.

15.01.2014 09:39

15.01.2014 10:05

6/13/2014

3

Due to bursting of ‘R’-ph CT of 220 KV Karad Ckt - IV at 220 KV S/S,

Mudshingi, Busbar Protection operated Resulting into tripping of all the bays

connected to 220 Bus at Mudshingi.

The CT was of Areva make commissioned in year 2007. The tan delta value

was within limits i.e. 0.0041 on date 3.6.2013.

220 KV Krd – Mudsingi - IV tripped on B ph. Zone3 at Karad end as a source.

220 KV Wathar - Mudshingi line tripped at Wathar end & 220 KV Karad –

Wathar line tripped at Karad end on B phase (Z-3) due to flame of failed ‘R’- ph

CT of Karad Ckt -IV came in the vicinity of ‘B’-ph CT of Wathar Ckt at

Mudshingi Substation.

6/13/2014

4

The CTs of 220 KV Karad – Kolhapur IV at Mudshingi were replaced.The CTs Wave Trap of 220 KV Mudshingi – Wathar were cleaned &The CTs Wave Trap of 220 KV Mudshingi Wathar were cleaned &taken in service.The arc resistance setting at Wathar of 220 KV Wathar –Mudshingiis revised.The Matter is taken with M/S. Areva regarding the failureof CT.

1

Occurrence at 400 KV S/s Indore on dt. 17.01.14

On dt.17.01.14 at 06:05 hrs , there was a fault on 400 KVIndore – Itarsi ckt. I. the “Y” phase pole of CB opened at 400KV I d d t 06 05 41 530 d t l d t

Annex-2.6

KV Indore end at 06:05:41.530 and auto reclosed at06:05:42.491. But the fault not cleared by then hence main IIrelay operated again at 06:05:42.877. and line tripped with “Y”phase Zone I indication from both the ends.

At the same time 400 KV bus bar protection scheme maloperated for Main Bus II and all the feeders & transformersconnected to Main Bus II tripped. Main Bus I and its elementremain charged and unaffected, hence there were nointerruption occurred due to these trippingsinterruption occurred due to these trippings.

The E.E. make, type FAC 34 Bus Bar Scheme is very old and itis mal operating after integration of ALSTOM make bus barscheme installed by PGCIL on expansion of 03 nos. 400 KVbays. As on date it is out of service and GE energy make, typeB- 90 Bus Bar protection scheme is being provided.

2

Analysis & Remedial Measures :

There was flash over on discs at location no. 464 of400 KV Indore – Itaesi I feeder, same has beenrectified and feeder charged at 17:16 hrs. on sameday.

E.E. make, type FAC 34 Bus Bar Protection schemedisconnected and GE Energy make, type B-90Numerical Bus Bar Protection scheme is beingprovided.

6/13/2014

1

Annex-2.8

Occurrence of 25/01/2014 at Navsari S/s

POWERGRID, WR‐II

Description of Occurrence

Connection of Lines on Bus-1/2

Feeders on 220kV Bus I: ‐ Feeders on 220kV Bus II: ‐

ICT‐1 ICT‐2

400 KV Gandhar‐Navsari #1 Line 400KV  Gandhar‐Navsari #2 Line

400 KV Vapi‐Navsari #2 Line 400 KV Vapi‐Navsari #1 Linep p

400 KV DGEN‐Navsari #1 Line 400 KV DGEN‐Navsari #2 Line

Bus Reactor

6/13/2014

2

SLD of 400/220kV Navsari ‐ GIS

Z

POWER GRID CORPORATION OF INDIA LTD      400 / 220 KV NAVSARI GIS SUBSTATION ( WR II ) 89 BB 1 E

400 KV BUS A89 BB 1

89 LE 1

89 A

Q 52

89 LE 1

89 BE

Q 52

Q 52

89 AE

Q 52

89 LE 1 89 LE 1

89 A 89 B89 A 89 A 89 B

89 AE

89 LE 1

89 AE

Q 52

89 LE 1

Q 52

89 A 89 B89 A 89 B

89 AE

89 A 89 B

89 AE

400 KV BUS B

89 AE

89 BB 2

89 A

89 AE

Q 52 89 BB 2 E

89 B89 A

89 LE 1

89 B

Q 52

89 B

89 AE

Q 52

89 A 89 B

89 AE

Q 52

89 LE 1

89 B

89 AE

89 LE 1

89 LE 289 LE 2

ABB400/220/33 KV

89 L 89 L

33 KV /440 V Transformer

ABB400/220/33 KV

ABB

ABB

89 LE 2

89 L

89 LE 2

89 L 89 L

89 LE 2

ICT  1    ICT  2   

89 L

DGEN  1

DGEN 2

89 LE 2

89 L

89 LE 2

VAPI 2VAPI 1GANDHAR 2GANDHAR 1

TO ACDB 

89 LE 2

403

REACTOR 63 MVAr

BUS COUPLER

89 L89 L

R – E fault occurred in 400kV Navsari‐Vapi#2 line (charged through Bus 1) at 32kM from Navsari S/s. After the dead time autorecloser attempt took place but as the fault was still persisting the line got tripped three pole. However, after approx. 

Tripping  DetailsAt 07:01:35 hrs

100ms the B Ph. LBB protection (which is inbuilt in the Busbar relay ABB make REB670) of 406 Bay i.e. Vapi#2 Bay which was connected on 400kV Bus 1 got mal operated. This resulted in the tripping of all the feeders connected on Bus#1 namely Gandhar#1, ICT#1, Bus Reactor and DGEN#1. Sequence of tripping is as detailed below: ‐

Sr. No. Feeder DetailTime of Tripping

Tripping Details

1 400kV Navsari Vapi#2 07:01:35 hrs Tripped on persisting fault in R Ph in Zone 11 400kV Navsari Vapi#2 07:01:35 hrs Tripped on persisting fault in R Ph in Zone 1

2 400kV Bus 1 07:01:36 hrsBecause of Operation of B Ph LBB function of Main 1 Busbar Unit (ABB, REB670)

3400kV Navsari Gandhar#1

07:01:36 hrs Because of operation of LBB

4 315MVA ICT#1 07:01:36 hrs Because of operation of LBB5 63MVAr Bus Reactor 07:01:36 hrs Because of operation of LBB6 400kV Navsari DGEN#1 07:01:36 hrs Because of operation of LBB

6/13/2014

3

Event List at 07:01:35 hrs14‐01‐25 07:01:35.031 VAPI‐2       P4 44 Zone 1 Optd On On

14‐01‐25 07:01:35.034 VAPI‐2       RE LM1 R‐ph trip Alarm Alarm

14‐01‐25 07:01:35.034 VAPI‐2       RE LM1 Dist Zone‐2 started Alarm Alarm

14‐01‐25 07:01:35.034 VAPI‐2       RE LM1 Dist Zone‐1 operated Alarm Alarm

14‐01‐25 07:01:35.066 VAPI‐2       Q5 2R CB R PHASE Open Open

14‐01‐25 07:01:36.050 VAPI‐2       RE C AR OPTD Alarm Alarm

14‐01‐25 07:01:36.076 VAPI‐2       Q5 2R CB R PHASE Intermediate Intermediate

14‐01‐25 07:01:36.117 VAPI‐2 2R CB R PHASE Closed Closed

14‐01‐25 07:01:36.123 VAPI‐2 LM1 Dist Zone‐1 operated Alarm Alarm

14‐01‐25 07:01:36.123 VAPI‐2 L Main‐1 Optd Alarm Alarm

14‐01‐25 07:01:36.123 VAPI‐2 LM1 R‐ph trip Alarm Alarm

14‐01‐25 07:01:36.123 VAPI‐2 LM1 Y‐ph trip Alarm Alarm

14‐01‐25 07:01:36.123 VAPI‐2 LM1 B‐ph trip Alarm Alarm

14‐01‐25 07:01:36.157 VAPI‐2 2Y CB Y PHASE Open Open

14‐01‐25 07:01:36.158 VAPI‐2 2B CB B PHASE Open Open

14‐01‐25 07:01:36.159 VAPI‐2 2R CB R PHASE Open Open

14‐01‐25 07:01:36.260 VAPI‐2       RE REB3 BAY 406 LBB OPTD Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       P4 REB3 BAY 408 TRIP Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       P4 REB3 BAY 401 TRIP Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       P4 REB3 BAY 406 TRIP Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       P4 REB3 BAY 404 TRIP Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       P4 REB3 BAY 403 TRIP Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       P4 REB3 DIRECT TRIP SEND Alarm Alarm

14‐01‐25 07:01:36.262 VAPI‐2       RE REB3 BUSBAR ZONE‐A TRIP Alarm Alarm

14‐01‐25 07:01:36.281 VAPI‐2       RE C BB Trip Relay Optd Alarm Alarm

14‐01‐25 07:01:36.283 VAPI‐2       RE REC BB Trip Relay Optd Alarm Alarm

14‐01‐25 07:01:36.283 VAPI‐2       P4 REC BB trip relay optd Alarm Alarm

14‐01‐25 07:01:36.283 VAPI‐2       P4 REC BB Trip Relay Optd Alarm Alarm

14‐01‐25 07:01:36.284 VAPI‐2       P4 REC BB Trip Relay Optd Alarm Alarm

14‐01‐25 07:01:36.284 VAPI‐2       RE REC BB Trip Relay Optd Alarm Alarm

14‐01‐25 07:01:36.309 VAPI‐2       P4 Q52 Breaker position indication Open Open

14‐01‐25 07:01:36.311 4BB1 Q52 Breaker position indication Open Open

14‐01‐25 07:01:36.325 401 Q52Y CB Y PHASE Open Open

14‐01‐25 07:01:36.325 403 Q52 Breaker position indication Open Open

DR Files – 400kV Navsari Vapi#2

6/13/2014

4

At 12:48 hrs

As 400kV Vapi Navsari#2 line was already out of service, therefore to find the cause of operation of LBB at 07:01 hrs, protection checking of this feeder was being done but again the LBB protection of B Ph of Main 1 Busbar relay for this feeder operated at around 12:09 hrs (although this time again there was no prefeeder operated at around 12:09 hrs (although this time again there was no pre condition of LBB feature) and the LBB optd contacts got latched. However, the tripping was not extended to other feeders in service. The LBB optd contacts, which had got latched, were not getting reset through the reset button on the Busbar Relay panel. This was not allowing the closing of 406 Circuit Breaker. Therefore, at around 12:48 hrs Main 1 Busbar protection has been put in block mode for both of the bus bar zones i.e. 400kV Bus 1 & Bus 2 and the DC supply of the Main 1 Busbar relay was switched off (so that the latched contacts can get reset), however, the tripping contacts of B Ph. Main 1 Busbar relay operated and tripped both 400kV pp g y p ppBus 1 & Bus 2 which resulted into the tripping of all the 400kV Feeders i.e. Gandhar 1&2, Vapi 1, ICT 1&2, Bus Reactor.

Sequence of Tripping At 12:48 hrs

Sr. o. Feeder Detail Time of Tripping Tripping Details

1 400 KV BUS 1 & BUS 2 12 48 H B f i f LBB1 400 KV BUS ‐1 & BUS‐2 12:48 Hrs Because of operation of LBB

2 400 KV Vapi‐Navsari # 1 12:48 Hrs Because of operation of LBB

3 Bus Reactor 12:48 Hrs Because of operation of LBB

4 ICT#1 12:48 Hrs Because of operation of LBB

5 ICT#2 12:48 Hrs Because of operation of LBB

6 400 KV Gandhar‐Navsari # 1  12:48 Hrs Because of operation of LBB

7 400 KV Gandhar‐Navsari # 2  12:48 Hrs Because of operation of LBB

8 400 KV DGEN‐Navsari # 1 12:48 Hrs Because of operation of LBB

9 400 KV DGEN‐Navsari # 2 12:48 Hrs Because of operation of LBB

6/13/2014

5

Time (ET+EM) Bay Device Object Text State Text Event Text

14‐01‐25 12:09:32.868 401 LM1 SOTF protection operated Alarm Alarm

14‐01‐25 12:09:32.982 4BB1 REB3 BAY 406 LBB OPTD Alarm Alarm

14‐01‐25 12:09:32.983 4BB1 REB3 BAY 406 TRIP Alarm Alarm

14‐01‐25 12:09:33.002 4BB1 C BB Trip Relay Optd Alarm Alarm

14‐01‐25 12:22:09.323 4BB1 C BB Trip Relay Optd Alarm Alarm

14‐01‐25 12:22:09.323 4BB1 REB3 BAY 406 TRIP Alarm Alarm

14‐01‐25 12:22:09.323 4BB1 REB3 BAY 406 LBB OPTD Alarm Alarm

14‐01‐25 12:27:37.768 VAPI‐2       RE C BB Trip Relay Optd Normal Alarm

14‐01‐25 12:27:37.774 VAPI‐2       RE C BB Trip Relay Optd Alarm Normal

14‐01‐25 12:27:37.789 VAPI‐2       RE C BB Trip Relay Optd Normal Alarm

14‐01‐25 12:27:37.795 VAPI‐2       RE C BB Trip Relay Optd Alarm Normal

14‐01‐25 12:47:16.257 VAPI‐2       RE REB2 M1‐Y ZA BLOCKED Alarm Alarm

14‐01‐25 12:47:16.283 VAPI‐2       RE REB3 M1‐B ZA BLOCKED Alarm Alarm

14‐01‐25 12:47:16.289 VAPI‐2       RE REB1 M1‐R ZA BLOCKED Alarm Alarm

Event List at 12:48 hrs

14‐01‐25 12:47:17.259 VAPI‐2       RE REB2 M1‐Y ZB BLOCKED Alarm Alarm

14‐01‐25 12:47:17.285 VAPI‐2       RE REB3 M1‐B ZB BLOCKED Alarm Obsolete status

14‐01‐25 12:47:17.288 VAPI‐2       RE REB1 M1‐R ZB BLOCKED Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 408 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 407 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 405 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 401 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 404 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 402 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 403 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BUSBAR ZONE‐A TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BUSBAR ZONE‐B TRIP Alarm Alarm

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 408 TRIP Alarm Alarm

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 402 TRIP Alarm Alarm

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 404 TRIP Alarm Alarm

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BUSBAR ZONE‐B TRIP Alarm Alarm

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BUSBAR ZONE‐A TRIP Alarm Normal

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 403 TRIP Alarm Normal

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 405 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2       RE REB3 BAY 407 TRIP Alarm Obsolete status

14‐01‐25 12:48:15.362 VAPI‐2 RE REB3 BAY 401 TRIP Alarm Alarm14 01 25 12:48:15.362 VAPI 2       RE REB3 BAY 401 TRIP Alarm Alarm

14‐01‐25 12:48:15.380 VAPI‐2       RE REC BB Trip Relay Optd Alarm Normal

14‐01‐25 12:48:15.380 4BB1 REC BB Trip Relay Optd Alarm Normal

14‐01‐25 12:48:15.380 4BB1 REC BB Trip Relay Optd Alarm Obsolete status

14‐01‐25 12:48:15.382 4BB1 REC BB Trip Relay Optd Alarm Alarm

14‐01‐25 12:48:15.382 4BB1 REC BB trip relay optd Alarm Intermediate

14‐01‐25 12:48:15.383 4BB1 REC BB Trip Relay Optd Alarm Intermediate

14‐01‐25 12:48:15.459 410 REB2 M1‐Y ZA BLOCKED Normal Obsolete status

14‐01‐25 12:48:15.459 409 REB2 M1‐Y ZB BLOCKED Normal Obsolete status

14‐01‐25 12:48:15.459 4BB1 REB2 M1‐Y ZA BLOCKED Normal Obsolete status

14‐01‐25 12:48:15.459 4BB1 REB2 M1‐Y ZB BLOCKED Normal Obsolete status

14‐01‐25 12:50:30.519 408 REB3 BUSBAR ZONE‐A TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 403 REB3 BUSBAR ZONE‐B TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 403 REB3 BAY 408 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 403 REB3 BAY 407 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 408 REB3 BAY 405 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 VAPI‐1   Q52Y REB3 BAY 401 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 4BB1 REB3 BAY 404 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 4BB1 REB3 BAY 402 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 4BB1 REB3 BAY 403 TRIP Normal Obsolete status

14‐01‐25 12:50:30.519 4BB1 REB3 BAY 408 TRIP Normal Obsolete status

Cause of Occurrence

For finding the cause of such operation, the Main 1 Busbar relay of B Phase was tested. However, it seems that the relay is having some internal problem as for the trippings the relay has not reported any p pp g y p yevent in the SAS and further there was no such internal event and DR in the relay for both the occurrences.

Therefore, the suspected relay was replaced with the spare relay after testing the same completely and after that Busbar protection has been taken into service. The suspected relay has been sent to M/s ABB (OEM) for Root Cause Analysis.

6/13/2014

1

ICT No. I ICT No. I ICT No. IIICT No. II ICT No.IIIICT No.III

220KV BUS I 220KV BUS I

Occurrence at 400/220kV Padghe s/s on 31.01.2014 at 16.45 hrs

ICT No. IVICT No. IV

E/F -Y E/F -Y

Annex-2.10

50 MVA 50 MVA T&RT&R

NalasoparaNalasopara Jindal Jindal

220KV BUS II 220KV BUS II

TemgharTemghar--II

200MVA 200MVA ICT ICT -- IIII

50MVA 50MVA BHELBHEL

200MVA 200MVA ICT ICT -- IIIIII

200MVA 200MVA ICTICT-- II

JambhulJambhul

B/CB/C

To 22KVTo 22KV

KambaKambaVasaiVasai WadaWada

200MVA 200MVA ICT ICT -- IVIV

Y- EY-E Z-II

Y-E Z-II

Y-E Z-I , AR &

HT E/F trip, Y ph, Z-III

start

HT

HT

Y-E Z-II

B/U O/C HS

Nashik IINashik II

100KV Bhiwandi 100KV Bhiwandi s/ss/s

II IIII

MohaneMohanes/ss/s

To To 22KV22KV

TemgharTemghar–– IIII

Vasa

iVa

sai

Pise

Pise

khar

bhav

khar

bhav

100KV 100KV PadghePadgheB/S B/S -- IIII

Ambernath Ambernath s/ss/s

Shahapur Shahapur s/ss/s

Murbad s/sMurbad s/s

VasaiVasai50

MVA

TF

No.

150

MVA

TF

No.

1

To 22KVTo 22KV

50 M

VA T

F N

o. 2

50 M

VA T

F N

o. 2

100KV 100KV PadghePadgheB/S B/S -- II

E/F -Y E/F -YHT

Under outage

220KV Anandnagar s/s220KV Anandnagar s/s220KV PAL 220KV PAL

100KV Dombivali 100KV Dombivali 100KV Taloja (past)100KV Taloja (past)

- Breaker NO

- Breaker OFF- Breaker tripped

Note:

SLDC - IIOccurrence at 400/220KV Padghe s/s on 31.01.2014 at 16:45hrs

220KV Main Bus – I

220KV Main Bus – II

220KV Transfer Bus (TBC)

Earth Rod

29LA 29LB 29LC

Local Earthing

29LDLocal Earthing

29LE

220kV Wada s/s

29LE

Wada end line is Earth

6/13/2014

2

Event Sequence from the gist of DRs :

Sr. No. Time Fault time Event Remarks

1 16:47:54:013 0.0msec Y-E fault started.Refer Padghe – Temghar DR.

2 16:47:54:310 297msec Padghe 220KV BC tripped2 16:47:54:310 297msec Padghe 220KV BC tripped

3 16:47:54:459 446msec 220KV Padghe – Temghar – 2tripped at Temghar end.

4 16:47:54:477 464msec 220KV Padghe – Vasai trippedat Vasai end.

5 16:47:54:480 467msec 400/220KV ICT – 2 tripped.6 16:47:54:520 507msec 400/220KV ICT - 4 tripped.

220KV Padghe – Jambhul – 2 Y7 16:47:54:631 618msec

gpole tripped & reclosed atJambhul end.

8 16:47:54:641 628msec 220KV Padghe – Jambhul – 1tripped at Jambhul end.

9 16:47:54:668 655msec 220/100KV ICT – 2& 4 tripped

10 16:47:54:753 740msec 220KV Padghe – Nasik – 2tripped at Nasik end.

Observation & Analysis:

On 31/01/2014,at 16.45 hrs, at 400/220KV Padghe s/s,220 KV B- Bus supply faileddue to mishaps in 220 kV Wada line bay which was under outage. This has causedthe fatal accident of the Technician &loss of load to the tune of 127 MW for about 1hrs also.

On 31 01 2014 the 220kV Padghe Wada line was taken out for maintenance workOn 31.01.2014, the 220kV Padghe – Wada line was taken out for maintenance workat both ends.

It is noted that the while Breaker & line side isolator is kept open, 220kV Main BBus isolator is closed at Padghe end for the said shutdown.

It is noted that temporary earthing were provided on both side of line isolator &lineearth isolator is also closed at both end.

It is noted that, at Padghe end, the maintenance technician is severely electrocuted &died on spot when tried to provide the temporary earthing on Main bus side of Yphase pole of breaker.

As such, at first, the Earthing rod in the hand of technician came in the inductionzone of live conductor which caused heavy flashover on breaker pole throughearthing rods & human body.

6/13/2014

3

The heavy arcing is also continued across the breaker pole through the temporarygrounding made on breaker side of the line side isolator.

The earthing wires of earthing rods put on Y phase are also found to be broken &melted.

Observation & Analysis:

This has created Y-E high arcing nature of fault in the system on B- Bus at Padghe s/s

This has started picking of remote end dist. prot in Zone II/Zone III & B/U E/F ofall the lines connected to 220 kV Padghe Bus. Back up protections of B/C,ICTswhich was feeding the fault was also picked up.

The healthy Main Bus-A is isolated from faulty Main Bus – B by tripping of B/Cbreaker on operation of Bus bar Back up O/C high set definite time protectionbreaker on operation of Bus bar Back up O/C high set definite time protection

The 315 MVA & 3X200 MVA , 400/220 kV ICT 2 & 4 connected to faulty Bus aretripped from HV/LV side on directional HV B/U E/F protection & thus isolated fromhealthy 400 kV Bus.

The 200 MVA ,220/100 kV ICT 2 & 4 connected to faulty Bus are tripped fromHV/LV side on LV B/U E/F protection & thus isolated from healthy 100 kV Bus.

Observation & Analysis:

The 220 kV grid lines such as Temghar II, Vasai & Nasik II which were connectedto faulty bus are also tripped from remote end on operation of distance protection onY-E fault in Zone II time.

Due to above tripping of sources lines/ICTs, the supply of 220 kV Main bus- B isfailed which have caused the loss of load of @ 11MW on 50 MVA 220/22 KVfailed which have caused the loss of load of @ 11MW on 50 MVA , 220/22 KVBHEL T/F.

The Event Sequence from the gist of DRs collected from Local/Remote endprotection is as below:

Sr. No. Time Fault time Event Remarks

1 16:47:54:013 0.0msec Y-E fault started. Refer Padghe –Temghar DR.

2 16:47:54:310 297msec Padghe 220KV BC tripped

3 16:47:54:459 446msec 220KV Padghe – Temghar – 2 tripped at3 16:47:54:459 446msec g g ppTemghar end.

4 16:47:54:477 464msec 220KV Padghe – Vasai tripped at Vasaiend.

5 16:47:54:480 467msec 400/220KV ICT – 2 tripped.6 16:47:54:520 507msec 400/220KV ICT - 4 tripped.

7 16:47:54:631 618msec 220KV Padghe – Jambhul – 2 Y poletripped & reclosed at Jambhul end.

8 16:47:54:641 628msec 220KV Padghe – Jambhul – 1 tripped atJambhul end.

9 16:47:54:668 655msec 220/100KV ICT – 2& 4 tripped

10 16:47:54:753 740msec 220KV Padghe – Nasik – 2 tripped atNasik end.

6/13/2014

4

Observation & Analysis:

As seen, the faulty bus is isolated from the system in @ 800 msec.

Due to this delayed clearing of fault, the Y phase jumper between line side isolator &breaker is also detached from the isolator end with flashover on support insulator ofisolator.

It is also noted that, during this occurrence, total failure of supply is occurred at220/100 KV Jambhul s/s, 220/100/22 KV PAL-Dombivali s/s & 100/22 KVDombivali MIDC s/s & part of 100/22 kV Taloja s/s due to tripping of double ckt.Source feeders i.e. 220 KV Padghe –Jambhul 1 & 2 as below.

At Padghe end, while 220kV Padghe – Jambhul-2 is connected to Main Bus –B(faulty Bus), the 220kV Padghe – Jambhul-1 is connected to Main Bus-A(healthy bus).

At first, distance protection at Jambhul end of 220kV Padghe – Jambhul-2 has sense thePadghe end fault in Y-E, Zone -3 which eventually developed in Zone II when B/C atPadghe end tripped & finally tripped in Zone 1 due to increase in fault current. Thisresulted into AR operation at Jambhul end.

Observation & Analysis:

Similarly, the directional E/Fat Jambhul end of 220 KV Padghe Jambhul -1 E/F is alsostarted in forward direction due to zero sequence current flow. However, it should haveresetted when B/C at Padghe end tripped & fault current started in reverse direction. But,it found to be remained in picked up condition & then eventually tripped. Thedirectional test of E/F Prot. is found to be in order. As such, the erratic behavior of ABBmake REF 615 relay is being checked.

Because of tripping of both Padghe-Jambhul lines -1 & 2 at Jambhul end, the total powerfailure occurred at 220kV Jambhul, PAL- Dombivali, Anandnagar , 100kV Dombivalis/s& 100 kV Taloja s/s which was partially feed from PAL- Dombivali. The water worksat Jambhul affected for about 35 minutes.

The load affected is about 116MW.

It is noted that, the 220 kV ABB RADSS Bus Bar protection at Padghe end did notoperate during such particular type of high arcing nature Bus fault. It is also to benoted that the same Bus Bar Protection was found to be correctly operated on30/05/2013 when 3 phase fault is occurred on both 220 kV Buses. As such ,Bus barprotection scheme shall be checked again shortly.

6/13/2014

5

Remedial Measure taken:

The EE, 400kV RS O&M Division have been requested to pass on necessary instruction tosubstation staff to confirm the isolation of equipment from system & work permit is to beissued/taken unless and until the Line /ICT /TF is isolated completely i.e. de-energizedcompletely from both end/side.

The EE, EHV Testing Division, Panvel is requested to check erratic behavior of ABB REF 615, g , qB/U protection –EF relay of Jambhul -1 at 220kV Jambhul s/s.

The 220KV breaker of Wada line is to be checked thoroughly for healthiness.

To minimize the effect of failure of 220KV long bus 2Nos of Hybrid pass is being provided on220KV Bus section to sectionalize existing long bus in to 4Nos bus section with providingnumerical bus bar protection. This is to be implemented on priority.

The ESR from SMS is not found in chronological order. The matter is to be referred to M/SABB f iABB for correction.

1

Occurrence at 400 KV S/s Nagda on dt. 31.03.14

On dt. 31.03.14 at 05:10 hrs. 220 KV CVT and LA on “R” phase of 220 KV Nagda – Ujjain ckt I failed at 400 KV S/s

Annex-2.11

phase of 220 KV Nagda Ujjain ckt I failed at 400 KV S/s Nagda end. Tripping occurred from Nagda end in Zone I and from Ujjain end in Zone II.

But the 220 KV CB at Nagda end not tripped due to problem in “R” phase tripping relay. Hence this delay caused the operation of LBB protection for this feeder.

Consequently the 220 KV elements connected on 220 KV Consequently, the 220 KV elements connected on 220 KV Main Bus I tripped, but 220 KV Main Bus remain charged and unaffected.

There were no interruption occurred to any area due to above trippings.

2

Analysis & Remedial Measures :

The failed 220 KV CVT and Wave Trap (make : WSI, year ofmfg. 1988) of 220 KV Nagda – Ujjain Ckt. I replaced on dt.01.04.14 and feeder charged at 16:38 hrs.

As such, owing to delay in tripping the LBB operation is said tobe correct. The problem of “R” phase tripping relay (EnglishEl t i k 86 l ) h b t d t d l tElectric make 86 relay) has been sorted out and completewiring and operation were checked by conducting relay testingand CB trip test before taking it in to service.

6/13/2014

1

On Dt. 05.02.2014 at 09:50 Hrs.,online shifting of 400 KV Karad-II on TBC at 400KV R.S. New Koyna was ycarried out. All operation were done sequentially but when Own Circuit breaker was hand tripped, then all the feeders on the bus-II tripped with indication 'Pole discrepancy’. The following are Window & Relay Indications at the i ftime of occurrence:

Sr. No. Name of feeder /TF Window

Indication Relay Indication Tripping Date & Time

Restoration Date & Time

Load Affected

1 400 KV Bus Coupler 05.02.14 10.26

NIL

1) 79/186,79/186X2 Multiplier of 400 KV NK-Stage4-II 2) 86A, 86B of 400 KV Jaigad-II 3) Tripping Relays of all Bus II feeders and Bus Coupler in Busbar protection panel

05.02.14 09.50 NIL

2 Jaigad II 05.02.14 10.43

3 400 KV 315 MVA ICT I 05.02.14 10.46

4 Karad II 05.02.14 11.10

5 400 KV Spare ICT 05.02.14 12.08

6 Dabhol II 05.02.14 11.38

7 Stage4 Ckt II 05.02.14 14.12

6/13/2014

2

The tripping of feeders on Bus-II was not extended from LBB or Bus bar Differential Relay, but it was due to extension of positive DC to trip bus while carrying out online TBC operation of 400KV Karad ckt.-II. Also the PDR indication is due to pick up of CMR due to DC leakage.

The DC Leakage was traced & located in cable from relay panel to CB MK box of 400 KV y pKarad-I and attended. Now there is no DC leakage.

6/13/2014

1

6/13/2014

2

Sr. No. Name of feeder /TF Window

Indication Relay Indication Tripping Date & Time

Restoration Date & Time

Load Affected

1 220KV Buscoupler 00:46 Hrs 03:03 Hrs Nil

Busbar protection Zone-2 operated.Busbar protection check zone operated.

Bus Bar Trip relay 96 optd. Relay Make ABB RADSSMain Zone- 2 ‘R’, ‘S’, ‘T’ flag operated, Check Zone ‘R’, ‘S’,‘T’ flag operated.

2 315MVA ICT 2 00:46 Hrs 03:13 Hrs Nil

3 315MVA ICT 1 00:46 Hrs 03:16 Hrs Nil

4 220KV Ichalkaranji 2 00:46 Hrs 03:18 Hrs Nil

5 220KV Mudshingi 2 00:46 Hrs 13:32 Hrs Nil

In yard inspection, it was observed that 220 KV Mudshingi - 2 bay ‘Y’ phase isolator rod of 29LC isolator lying on the ground and ladder was placed onisolator lying on the ground and ladder was placed on ‘C’ Isolator. After detailed investigation it was concluded that there was a theft attempt and flashover took place during uninstallation of Aux Bus ‘Y’ phase isolator leading to Bus bar operation. The protection operated is in order.

1

Occurrence at 220 KV S/s Pandurna on 12.03.14

On dt. 12.06.14 at 15:17 hrs., 220 KV Pandurna – Sarnifeeder tripped on transient fault with “B” phase (RYB) Zone I

Annex-2.15

pp p ( )indication, with a fault distance 24.82 kms. and auto reclosewas in process.

Simultaneously LBB scheme of this feeder mal operated dueto wiring mistake at CB end due to confusion of RYB & ABCsequence formation. At CB end “Y” phase pole of the CBtripped instead of “B” phase pole.

Consequently, 220 KV feeders and transformer connected to220 KV Main Bus tripped at 220 KV S/s Pandurna, andinterruption occurred to 220 KV S/s Pandurna, 132 KV S/sMultai and 132 KV Railway Traction feeders for about 27minutes.

2

Analysis & Remedial Measures:y

220 KV supply at 220 KV S/s Pandurna resumed at 15:30hrs. from 220 KV S/s Kalmeshwar (MSTCL). Then totalsyetm normalized at 220 KV S/s Pandurna by 15:50 hrs.

Wiring mistake at CB end rectified and checked thoroughlyfor any discrepancy After desired rectification it is taken infor any discrepancy. After desired rectification it is taken into service.

1

Occurrence at 220 KV S/S South Zone, Indore on13.03.14

On dt.13.03.14 at 09:20 hrs., 132 KV PT (Make : TELK, Yr. ofMf 1978) t d “R” h f 132 KV M i B f il d t

Annex-2.16

Mfg. 1978) connected on “R” phase of 132 KV Main Bus failed at220 KV S/s South Zone, Indore and created 132 KV Bus Fault.Pre fault status at 220 KV S/s South Zone, Indore;

2

Most of the 132 KV feeders from 220 KV S/s South Zone, Indore wererunning in radial mode, therefore 4 x 132 KV Incoming of 220/132 KVrunning in radial mode, therefore 4 x 132 KV Incoming of 220/132 KVtransformers were the source for the 132 KV Bus Fault. Which tripped onhigh set over current and earth fault protection and isolated the faultwithin 300 msec.Due to these trippings interruption occurred as following;

Analysis & Remedial Measures:Owing to 132 KV Bus Fault trippings occurred wereOwing to 132 KV Bus Fault, trippings occurred weresaid to be in order.132 KV Supply at 220 KV S/s resumed at 09:40 hrs.after isolating the failed PT, and 132 KV systemnormalised with 2nd set of 132 KV PTs by 09:50 hrs.The remote 132 KV substation having other sourceswere normalized within 10 minuteswere normalized within 10 minutes.Failed 132 KV PT (Make : TELK, 1978) was very oldand has damaged other two PTs of same lot. All thesethree 132 KV PTs replaced by new 132 KV PTs on dt.14.03.14 and taken in to service at 11.:20 hrs.

1

Occurrence at 400 KV S/S Bina on 15.03.14

On dt.15.03.14 at 15:20 hrs. 220 KV Bina – Shivpuri feeder tripped on a transient fault fro both the ends, but the 220 KV

Annex-2.17

pp ,CB got stuck at Bina end, due to burring of tripping coil. This feeder was running on 220 KV Main Bus I at 400 KV S/s Bina.

Therefore, LBB protection of above CB operated and all the feeders and transformers connected to 220 KV Main Bus I tripped at 400 KV S/s Bina as following;

1. 400/220 KV, 315 MVA X-mer – I & III – at 400 KV S/s Bina.2 220 KV Bina Sagar Ckt I at 400 KV S/s Bina2. 220 KV Bina – Sagar Ckt – I at 400 KV S/s Bina.3. 220 KV Bina – Bina Interconnector – I at 400 KV S/s Bina. 4. 220 KV Bina – Guna Ckt – I at 400 KV S/s Bina.5. 220 KV Bina – Gwalior Ckt. – I at 400 KV S/s Bina.6. 220 KV Bina – Shivpuri Ckt. from both end.

The 220 KV Main Bus II remain charged and unaffected, hence no interruption occurred to any area due to these trippings.

2

Analysis & Remedial Measure :

Defective tripping coil replaced and wiring and mechanism checked thoroughly for any discrepancy, nothing detected noticeable. overhauling of CB mechanism is scheduled.

6/13/2014

1

OCCURRENCE DATED 16/03/2014 AT220 C S S O

Annex‐2.18

On date 16.03.2014 at 20:10 hrs the Y phase CT of 220KV Jalana Circuit –I at 220 KV Chikhali substationfailed/ burst resulting in the operation of bus bar relay.All the 132 KV feeders & ICTs connected to the bus

i d h h b b l i Th

220 KV CHIKHALI SUBSTATION 

got tripped through bus bar relay operation. Thedetails of the trippings occurred are as shown in tablebelow:

Sl. No.

Name of the

substation

Name of the bay Time of tripping

Time of charging

Remarks

1. 220 KV Chikhali

substation

220 KV JalanaCircuit –I

2010 Hrs 2240 Hrs on Dt. 20.03.2014

Tripped due to operation of bus bar

protection relay.2 220 KV Jalana 2010 Hrs 2240 Hrs on2. 220 KV Jalana

Circuit –II2010 Hrs 2240 Hrs on

Dt. 20.03.20143. 220 KV Paras

Circuit –I2010 Hrs 20:42 Hrs

4. 220 KV ParasCircuit –II

2010 Hrs 20:53 Hrs

5. 220/132 KV 200 MVA ICT-1

2010 Hrs 20:45 Hrs

6. 220/132 KV 200 MVA ICT-2

2010 Hrs 20:54 Hrs

6/13/2014

2

INVESTIGATION1. Due to failure of Y phase CT of 220 KV Jalana Ckt –I at 22o

KV Chikhali S/Stn. the operation of BUSBAR is in order andtripped all feeders connected to 220KV Bus The 22o KVtripped all feeders connected to 220KV Bus. The 22o KVTBC, was already in trip condition i.e. free.

2. The Jalna Ckt‐I was commissioned on dt. 07.08.2013. The CT isof Make‐SCT, Gaziabad ,Sr. No. 2009/1411 DOC‐ 07.08.2013.However, due to non availability of 220 KV CT it was notreplaced hence delay.

3. The other two CTs SCT make installed to R & B Ph were also3checked and Tan‐Delta of R Ph found 0.196 % & of B Phfound 1.17 % . The B Ph CT having high Tan Delta values i.e.above permissible limit should be replaced before chargingthe circuit.

AREA AFFECTED1. Area is not affected as load is managed by other EHV S/Stns. 

Connected in grid  Connected in grid. 

REMEDIAL MEASURES1. The failed CT is of Make‐SCT, Gaziabad , Sr. No. 2009/1411, 

DOC 8DOC‐ 07.08.2013.2. The failure of CT & increase in Tan Delta values of the SCT

make CTs in short span is not desirable and matter should bereferred to the manufacturer. The CT is in Guarantee period.

6/13/2014

3

BusbaroperatedatChikhali S/Stn.onDt.16.03.2014.Jalna II  Jalna I  Paras II  Paras I 

Y Ph CTBurst

Main I 

Aux.

220 KV Bus 

220/132 KV ICT I220/132 KV ICT II

132 KV Bus 

‐ Breaker Tripped

‐ CB already in trip condition

6/13/2014

1

OCCURRENCE DATED 09/03/2014 AT220 KV AMRAVATI SUBSTATION 

Annex‐2.19

On date 09.03.2014 at 2150 hrs the B phase CT of 132 KV Achalpur feeder at 220 KV Amravati substation failed/ burst resulting in the operation of bus bar relay. All the 132 KV feeders/ T/Fs connected to the affected bus got tripped through bus bar relay operation. The details of h   i i   d      h  i   bl  b l  the  trippings occurred are as shown in table below: 

Sl. No.

Name of the

substation

Name of the bay Time of tripping

Time of charging

Remarks

1. 220 KV Amravati substation

132 KV Achalpur 2150 Hrs 1701 Hrs (10.03.2014)

Tripped due to operation of bus bar

protection relay (REB 2 132 KV Ch Bzr 2150 Hrs 2245 Hrs500).

The ICT-2 LV side was charged through 132 KV TBC, and it tripped through bus bar relay operation.

2. 132 KV Ch Bzr 2150 Hrs 2245 Hrs

3. 132 KV Morshi 2150 Hrs 2232 Hrs

4. 132 KV New Akola 2150 Hrs 2246 Hrs

5. 132 KV bus interconnector

2150 Hrs 2230 Hrs

6. 220/132 KV 200 MVA ICT 1

2150 Hrs 2243 HrsMVA ICT-1

7. 220/132 KV ICT-2 (LV side-TBC CB)

2150 Hrs 2244 Hrs

8. 132KV Achalpur substation

132 KV Amravati 2150 Hrs 1701 Hrs (10.03.2014)

Distance protection, B phase, Earth,

Zone-2

6/13/2014

2

INVESTIGATION1. Due to failure of B ph CT of 132KV Achalpur feeder at 220KV

Amravati S/Stn. the operation of BUSBAR Zone‐1 is in order andtripped all feeders connected to zone‐1 alongwith interconnectorand saved half 132KV Bus. Tripping of 132KV Amravati line atAchalpur S/Stn. on distance protection, B ph, Zone‐2 is in order.

2. The HV CB of 220/132 KV ICT‐2 is wired up to trip for operation of96 LV relay, it did not trip because its fuse link was loose – did notextend trip command. It has been corrected.

3. The tan delta value of the said CT, measured last on date 27.05 2013,was 0.019 (at 10 KV measurement). The condition of the CT was,therefore, alarming and was suggested for replacement. Howeverdue to non availability of 132 KV CT it was not replaced. Heavy rainswith hailstorm had lashed the region for the past few days and thepossibility of the CT getting damaged during the hailstorm and itssubsequent insulation failure cannot be ruled out.

AREA AFFECTED1. Area fed from 132 KV Morshi and Warud substations affected 

for 42 minutes  The total load affected was around 14 MWfor 42 minutes. The total load affected was around 14 MW.

6/13/2014

3

REMEDIAL MEASURES1. The failed CT is replaced by spare available CT at Morshi and 

the feeder is charged. 2. The failure of CT in short span of 3 years is not desirable hence

matter should be referred to the manufacturer. The Testing ofother Apporva make CTs should be carried out and if thevalues are not within the permissible limits should bereported to C.O. and the manufacturer.

SINGLE LINE DIAGRAM‐OCCURRENCE DATED 09.03.2014 (220 KV AMRAVATI SUBSTATION)

132/11 KV TF‐1

220/132 KV ICT‐1

220/132 KV ICT‐2

Tiwsa Ambazari132/11 KV 

TF‐3

132/11 KV TF‐2

Transfer bus

TBC

132/66 KV TF‐2

ε

132/66 KV TF‐1

Akola (old)

Lalkhedi

Morshi

Akola  Chandur Bzr

Achalpur

WarudSYMBOLS

CB tripped

CB not tripped

6/13/2014

1

Annex.-2.20

Occurrence of 19/03/2014 at Rajgarh S/s

POWERGRID, WR‐II

Description of Occurrence

Connection of Lines on Bus-1/2

Feeders on 400kV Bus I: ‐ Feeders on 400kV Bus II: ‐

400kV SSP Rajgarh 1 400kV Khandwa Rajgarh 1

400kV SSP Rajgarh 2 400kV Khandwa Rajgarh 2

400kV Nagda Rajgarh 1 400/220kV ICT 1

400kV Nagda Rajgarh 2 400/220kV ICT 2

‐‐‐‐‐‐ 400kV Bus Reactor

6/13/2014

2

SLD of 400/220kV Rajgarh S/s

 

41052 41352 41652

MAIN BUS‐I 

SSP‐1  SSP‐2  NAGDA‐1 NAGDA‐1 KASOR‐1 KASOR‐2

40152  40452  40752

FSC‐1 FSC‐2WT WT 

WT WT

WTWT

CVT CVT

CVT  CVT CVTCVT 

40352 

40252 

40652 

40552 

40952 

40852 41152 41452 41752

41252 41552BUS CVT 

BUS CVT 

MAIN BUS‐II 

315MVA ICT‐1KHANDWA‐2

400KV SWITCHYARD RAJGARH SUBSTATION 

315MVA ICT‐2 KHANDWA‐2 

WT WT 

LA LA 

LALA

LA

   125  MVAr BUS REACTOR

CVT  CVT 

Sequence of Tripping At 12:13:57 hrs

At 12:13:56 hrs, B – E fault occurred in 400kV Nagda Rajgarh # 2 (charged through Kasor#2 Bay undercontingency arrangement) at 93.1kM from Rajgarh S/s. After dead time, autorecloser attempt tookplace but as the fault was still persisting the line got tripped three pole. At the same time, Busbar

Sr. No. Feeder Detail Time of Tripping Tripping Details

1. 400kV Nagda Rajgarh#2 12:13:57 Tripped on persisting fault in RΦ in Zone1

2.  400kV Bus#2 12:13:57 hrs Because of operation of Busbar protection

3. 400kV Main Bay of Khandwa Rajgarh#1&2 12:13:57 hrs Because of operation of Busbar protection

operated for 400kV Bus 2 and Main Bays connected on Bus#2 of all the feeders namely Khandwa#1&2,ICT#1&2 and Bus Reactor got tripped. However, the all the feeders remained charged through Tie bays.

4. 400kV Main Bay of 315MVA ICT#1&2 12:13:57 hrs Because of operation of Busbar protection

5. 400kV Main Bay of 125MVAr Bus Reactor 12:13:57 hrs Because of operation of Busbar protection

6/13/2014

3

DR Files – 400kV Rajgarh Nagda#2

Cause of OccurrenceIt has been observed that in newly commissioned Kasor#2 Tie Bay (charged as Nagda#2 Tie Bay) of 400kV Nagda Rajgarh#2 (contingency arrangement FSC of 400kV Rajgarh Kasor#2), CT star point was found reverse and which has led to operation ofstar point was found reverse and which has led to operation of 400kV Busbar 2 protection.

The same has been corrected and Tie bay was taken into service after that.

Annexure - 3

SN Voltage KV Element Name Tripping

DateTripping

Time

Resto-rationDate

Resto-rationTime

Detail Reason of Tripping

1 765 Seoni-Wardha # 2 3.12.13 16:00 3.12.13 16:33 Line tripped due to Buckholz relay operation in L/R at Wardha

2 400 Boisar - Padhge 5.12.13 15:33 5.12.13 16:03 Line tripped due operation of Reactor Buchholz relay at MSETCL Padghe end. Line charged without line reactor

3 400 Raipur-Sipat # 3 12.12.13 16:51 12.12.13 17:31 Line tripped due to operation of TEED protection at NTPC Sipat 4 400 Mouda-Wardha # 2 3.1.14 17:48 3.1.14 20:11 Line tripped due to Tie bay Bph CT problem at Mouda NTPC end

5 400 Akola-Aurangabad (PG) # 2 27.1.14 16:57 27.1.14 17:36 Line tripped during Bus bar protection testing at Akola (MSETCL) end

6 400 KWPCL-Raipur 28.2.14 07:55 1.3.14 12:39 Line charged but tripped on Y-E fault.F/L=164.5km from Raipur. Insulator decappinng at loc. no. 484.

7 400 Aurangabad (MSETCL) -Aurangabad (PG)# 2 3.3.14 21:55 3.3.14 22:05 Line tripped on R-ph-Efault, F.L=34.7Km from A'bad(PG).

8 400 Raipur-Wardha # 1 4.3.14 09:30 4.3.14 09:58 Line tripped after receipt of DT at Raipur end.

9 400 Bhilai -Bhadrawati 14.3.14 14:27 14.3.14 15:25Line tripped on Bph - E fault due to cutting of trees under line ROW by villagers . F/L= 89 Km from Bhilai end. Tree fall between span loc. 247-248.

10 400 Korba-Mahan ( Essar) 15.3.14 06:59 15.3.14 09:54 Line tripped from Korba end only due to DT received from Mahan end

11 400 Bhilai - Seoni 19.3.14 13:15 19.3.14 13:15 Line autoreclosed successfully at both ends on Rph - Efault, FL-188 Km from Seoni end.

12 400 Akola-Aurangabad (PG) # 2 17.2.14 01:02 17.2.14 01:17 Line tripped due to problem in line reactor at Akola end

13 400 Raipur-Wardha # 1 23.2.14 17:38 23.2.14 17:43 Line tripped due to Rph - Bph fault. Fault distance from Raipur end 200 kms & from Wardha end 175 Kms.

14 400 Balco-Birsinghpur 27.2.14 02:13 27.2.14 02:18 Line tripped due to R ph - E fault. F/L=24Km from Balco & 149Km from Birsingpur.

15 400 KWPCL-Raipur 28.2.14 07:55 28.2.14 24:00 Line charged but tripped on Y-E fault.F/L=164.5km from Raipur. Insulator decappinng at loc. no. 488.

16 765 Seoni - Bina I 3.12.13 22:00 3.12.13 22:10 A/T due to operation of O/V protection at Bina

17 765 Bina (pg) - Indore i 5.12.13 19:32 5.12.13 19:42 A/T on operation of O/V protection at Indore

18 400 Vindhyachal - Jabalpur ii 7.12.13 09:48 7.12.13 09:48 A/R successfully from both sides due to transient Y-E fault

19 400 Vindhyachal (ntpc) - Sasan II 7.12.13 12:47 7.12.13 14:18 A/T due to operation of Reactor Diff protection at NTPC VIN end.

20 400 / 220

ICT 2 - Satna 9.12.13 19:54 9.12.13 20:56 A/T due to melting of CT clamp of 220KV side Tie Bay

21 765 Satna - Bina (PG ) I 22.12.13 18:35 22.12.13 18:40 A/T at Bina end only on receipt of D/T at Bina end.

22 400 Indore - Asoj ii 23.12.13 12:29 23.12.13 12:55 A/T on operation of Bus Bar protection at Indore(MP)

23 400 Indore (MP) - Indore (PG) - I 23.12.13 12:29 23.12.13 12:45 A/T on operation of Bus Bar protection at Indore(MP) end.

24 400 Indore (MP) - Indore (PG) II 23.12.13 12:29 23.12.13 15:28 A/T on operation of Bus Bar protection at Indore(MP) end.

25 765 Satna - Bina (PG ) I 28.12.13 16:01 28.12.13 18:00 A/T on operation of O/V protection at Bina

26 400 Bina - Shujalpur I 30.12.13 17:27 30.12.13 18:49 A/T on B-ph to E/F (persisting fault)

27 400 Indore -Asoj II 1.1.14 00:41 1.1.14 17:44 A/T on Y-ph to E/F at both ends (Insulator flashover)

28 400 Itarsi - Indore I 1.1.14 02:56 1.1.14 15:29 A/T on B-ph to E/F at both ends (Insulator flashover)

29 400 Indore (MP) - Indore (PG) I 1.1.14 04:33 2.1.14 06:38 A/T on Y-B ph to Ph fault

30 765 Jabalpur (pooling) - Bina I 3.1.14 14:03 3.1.14 17:18 A/T due to B-ph to E/F (persisting fault)

31 765 Jabalpur - Bina II 6.1.14 04:05 6.1.14 04:15 A/T due to operation of O/V protection at Jabalpur

32 765 Jabalpur - Bina II 7.1.14 05:00 7.1.14 05:10 A/T due to operation of O/V protection at Jabalpur

33 765 Seoni - Bina I 7.1.14 20:26 7.1.14 21:20 A/T on Y-E fault (persisting fault)

34 400 Gandhar - Dehgam II 8.1.14 08:38 8.1.14 09:27 A/T on R - Y ph to ph fault

35 400 Vindyachal - Sasan II 9.1.14 03:21 9.1.14 12:01 A/T at VSTPP end only due to D/T receipt from SASAN end

36 765 Sasan - Satna II 10.1.14 18:26 10.1.14 19:36 A/T on Y-E (persisting fault)

37 400 Vindyachal - Jabalpur IV 10.1.14 22:25 10.1.14 23:17 A/T due to B-E (persisting fault)

38 765 Jabalpur (pooling) - Bina I 10.1.14 23:50 10.1.14 23:52 A/T due to operation of O/V protection at Bina

39 400 Mundra - Jetpur II 15.1.14 01:58 15.1.14 02:08 A/T on DT receive due to O/V at Mundra end.

40 400 Itarsi - Indore I 17.1.14 06:05 17.1.14 08:54 A/T on operation of 400kV Bus 2 Bus Bar protection at Indore

41 400 Itarsi - Indore II 17.1.14 06:05 17.1.14 07:53 A/T on operation of 400kV Bus 2 Bus Bar protection at Indore

42 400 Indore (MP) - Indore (PG) I 17.1.14 06:05 17.1.14 07:44 A/T on operation of 400kV Bus 2 Bus Bar protection at Indore

43 400 Indore (PG) - Indore (MP) II 17.1.14 06:05 17.1.14 07:57 A/T on operation of 400kV Bus 2 Bus Bar protection at Indore

44 400 Indore - Asoj II 17.1.14 06:05 17.1.14 08:08 A/T on operation of 400kV Bus 2 Bus Bar protection at Indore

45 765 Sasan - Satna II 18.1.14 00:13 18.1.14 00:23 A/T on operation of O/V protection at Satna

46 765 Sasan - Satna I 18.1.14 00:13 18.1.14 00:13 A/R successful on R-E (transient) fault

47 400 Vindyachal - Jabalpur IV 18.1.14 08:08 18.1.14 08:42 A/T on B - E (persisting) fault

48 765 Sasan - Satna II 21.1.14 00:35 21.1.14 00:35 A/R successful on Y-E (transient) fault.

49 400 Nagda - Dehgam II 21.1.14 03:48 21.1.14 15:05 A/T on B-E fault (insulator flashover)

50 765 Satna - Bina (PG) I 22.1.14 23:10 22.1.14 23:20 A/T on operation of O/V protection at Satna end.

51 765 Satna - Bina (PG) I 24.1.14 06:41 24.1.14 07:45 A/T on operation of REF at Bina SS due to failure of NGA LA at Bina

52 400 Vapi - Navasari (GIS) II 25.1.14 07:01 25.1.14 15:23 A/T on R-E (persisting fault)

53 400 Vindhyachal (NTPC) - Sasan III 25.1.14 22:33 25.1.14 22:43 A/T on operation of O/V protection at VSTPP end

54 765 Satna - Bina (PG) I 25.1.14 22:50 25.1.14 23:00 A/T on operation of O/V protection at Satna end

55 400 Vindhyachal - Satna III 26.1.14 02:03 26.1.14 02:13 A/T on operation of O/V protection at Satna end

56 765 Sasan - Satna II 26.1.14 03:00 26.1.14 03:10 A/T on operation of O/V protection at Satna end

57 765 Jabalpur (pooling) - Bina II 28.1.14 15:47 28.1.14 21:15 A/T due to failure of Y-ph Line LA at Bina

58 765 Satna - Bina(PG) I 29.1.14 15:53 29.1.14 16:48 A/T on operation of O/V protection at Bina.

59 400 Nagda - Dehgam II 29.1.14 20:13 29.1.14 20:23 A/T on operation of O/V protection at Nagda.

60 765 Jabalpur (Pooling) - Bina I 30.1.14 21:48 30.1.14 21:58 A/T on operation of O/V protection at Jabalpur

61 400 Khandwa - Dhule II 6.2.14 17:46 7.2.14 12:38 A/T on R-- E (persisting fault)

62 765 Gwalior - Bina I 16.2.14 23:58 17.2.14 00:08 A/T on operation of O/V protection at Gwalior end.

63 765 Sasan - Satna I 17.2.14 12:32 17.2.14 13:43 A/T on DT receive at Satna end on operation of LBB Sasan

64 400 Vindhyachal - Jabalpur IV 22.2.14 15:27 22.2.14 15:37 A/T on B-E (persisting fault)

65 400 Jabalpur - Jabalpur (pooling) II 22.2.14 18:09 22.2.14 18:22 A/T on B-E (persisting fault)

66 400 Satpura - Itarsi 24.2.14 17:35 24.2.14 17:35 A/R successful on transient B - E fault

67 400 Seoni - Khandwa I 25.2.14 21:49 25.2.14 22:52 A/T on R-E (persisting fault)

68 400 Mundra - Limbdi I 26.2.14 07:19 27.2.14 13:50 A/T on R&Y Ph. to ph fault

69 765 Bina - Indore 26.2.14 11:40 26.2.14 11:40 A/R successfully on R-E (transient fault)

70 765 Jabalpur (pooling) - Bina I 26.2.14 18:24 26.2.14 18:34 A/T on B-E (persisting fault)

71 400 Damoh - Birsinghpur II 27.2.14 07:30 27.2.14 07:30 A/R successfully on Y-E (transient fault)

72 400 Satna - Biina (PG) III 27.2.14 10:07 27.2.14 18:28 A/T on R-E (persisting fault)

73 400 Vindhyachal - Satna III 27.2.14 10:28 27.2.14 21:38 A/T on Y-E (persisting fault)

74 765 Jabalpur (pooling) - Bina I 27.2.14 18:39 27.2.14 20:40 A/T due to operation of Reactor PRV at Bina during heavy rain.

75 400 Sasan (reliance) - Jabalpur 27.2.14 20:12 27.2.14 21:05 A/T on B-E (persisting fault)

76 400 Damoh - Birsinghpur II 28.2.14 01:33 28.2.14 01:43 A/T on operation of O/V protection at Damoh

77 400 Damoh - Bhopal I 28.2.14 01:35 28.2.14 01:45 A/T on operation of O/V protection at Damoh

78 765 Agra - Gwalior II 28.2.14 15:44 28.2.14 20:36 A/T due to conduction of LA at Agra (NRTS#1)

79 765 Gwalior - Bina II 28.2.14 16:45 28.2.14 17:15 A/T due to operation of Reactor REF protection at Bina.

80 765 Gwalior - Bina I 28.2.14 21:38 28.2.14 22:13 A/T on operation of O/V protection at Gwalior

81 400 Sasan (reliance) - Jabalpur 1.3.14 17:25 1.3.14 17:25 A/R successful on transient B - E Fault

82 400 Indore - Asoj II 1.3.14 20:27 1.3.14 20:37 A/T on operation of O/V protection at Asoj.

83 765 Satna - Gwalior I 10.3.14 13:48 10.3.14 15:10 A/T during SAS configuration changing at Gwalior

84 400 Satna - Bina (PG) II 10.3.14 14:55 10.3.14 15:25 A/T on R - E (persisting fault)

85 400 Satna - Bina (PG) I 10.3.14 17:04 10.3.14 17:58 A/T on Y - E (persisting fault)

86 400 SSP - Rajgarh I 11.3.14 19:06 11.3.14 19:06 A/R successfully on transient Y - E fault87 400 Jabalpur - Itarsi II 11.3.14 22:51 11.3.14 22:51 A/R successfully on transient R - E fault88 400 Bhachau - Ranchodpura II 12.3.14 13:38 12.3.14 20:45 A/T on R-B fault

89 765 Agra - Gwalior II 15.3.14 12:16 15.3.14 12:39 A/T at Gwalior end only due to damage in the CVT cable.

90 400 Mundra - Jetpur I 19.3.14 07:21 19.3.14 08:12 A/T on R - E (persiting fault)

91 400 Rajgarh - Nagda II 19.3.14 12:14 22.3.14 09:31 A/T on B - E (persiting fault)

92 400 Jabalpur - Jabalpur (pooling) II 24.3.14 21:38 24.3.14 21:48 A/T on B - E (persisting fault)

93 400 Itarsi - Indore II 29.3.14 13:16 29.3.14 13:16 A/R successful on transient Y - E fault

94 400 Birsinghpur-Katni -II 03.03.14 23:34 04.03.14 6:39 Line tripped on O/V due to direct trip received from Katni end.

95 400 Birsinghpur-Katni -II 04.03.14 12:38 Line tripped on overvoltage due to direct trip received from Katni end. Line not charged as per system requirement.

96 220 Birsinghpur - Amarkantak - III 12.03.14 19:04 12.03.14 20:13 Line tripped on `R` phase fault, 83 KM from Birsinghpur97 220 Sarni S/s Inter-Connector – I 12.03.14 15:17 12.03.14 15:03 Tripped on Earth Fault from Power House end. 98 220 Sarni S/s Inter-Connector – I 15.03.14 20:35 16.03.14 14:15 Tripped on `B` Phase fault, E/F relay operated.

99 220 Sarni S/s Inter-Connector – II 15.03.14 20:35 15.03.14 21:19 Tripped on `B` Phase fault.

100 220 Sarni S/s Inter-Connector –I 31.03.14 10:55 31.03.14 11:05 Tripped on R & Y Phase fault.

101 220 Amarkantak (Chachai) - Jabalpur - II 01.03.14 19:17 01.03.14 19:03 Tripped on `R` Phase fault, Z-I.

102 220 Amarkantak (Chachai) - Sidhi 12.03.14 15:00 22.03.14 18:45 Tripped on A &B Phase fault, Z-I.

103 220 Amarkantak (Chachai) Traction Feeder - II 12.03.14 19:15 12.03.14 20:09 Tripped on `C` Phase fault.

104 220 Amarkantak (Chachai) Traction Feeder - I 12.03.14 19:02 12.03.14 20:08 Tripped on `C` Phase fault.

105 220 Jabalpur - II 22.03.14 23:04 22.03.14 23:52 Tripped on `A` Phase fault, Z-I.

Format for Collecting information in regard to implementation of Recommendation of the Enquiry Committee. Annexure‐5

FORMAT ‐1 (PROTECTION AUDIT)

WR Constituent(D)Target date for completion of 

audit.(E ) No. of S/S where deficiencies detected.

132 kV 220 kV 400 kV 765  kV HVDC Total 132 kV 220 kV 400 kV 765  kV HVDC Total 132 kV 220 kV 400 kV 765  kV HVDC TotalMaha 119 119 0 NA NAGuj 47 81 11 0 0 139 47 74 0 0 0 121 11 19 11 0 0 52 October ‐2013 for 132 & 220 kV 36+55 = 91CG

MPPGCL 9 4 2 0 0 15 9 4 2 0 0 15 5/1/2014 NAMPPTCL 54 5 59 54 5 59 12/31/2013OSP 1 1 1 1 9/30/2013ISP 1 1 1 1 9/30/2013

MP Total 9 59 9 0 0 76 0 0 0 0 0 0 9 59 9 0 0 76WR‐I (PG) 0 0 8 3 1 0 0 8 3 1 0 0 0 0 0 0 NA NAWR‐II (PG) 11 3 0 14 11 3 0 14 0 0 0 NA 0WR‐I (NTPC)WR‐II (NTPC)

Total

(I) Reason/remarks for rectification of deficiencies requiring period of 

more than one year.

(J) Cost estimates for removal of deficiencies.

132 kV 220 kV 400 kV 765  kV HVDC S/S Total 132 kV 220 kV 400 kV 765  kV HVDC S/S Total 132 kV 220 kV 400 kV 765  kV HVDC S/S TotalMaha NA NA NA NA NAGujCGMP

WR‐I (PG) NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NAWR‐II (PG) NA NA NAWR‐I (NTPC)WR‐II (NTPC)

(A) Total No. of S/S in region. (B) No. of S/S identified for audit. ( C) No. of S/S yet to be audited

Agency for furnishing  information.

Recommendation 9.1.1: There is a need to review protection schemes.  This Committee concurs with recommendation of previous enquiry committee that a throrough third party protection audit need to be carried out in time bound manner. This exercise  should be repeated periodically and monitored by RPC's.                                           Action : RPCs, CTU, STUs.

(F) Action plan (on observation  of third party protection audit) finalization date/Target date for finalizing plan

(G) Detail of S/S where no procuremnet is required for removal of deficiencies. No. of S/S                          

Target date for removal of  deficiencies

(H) Detail of S/S where procurement is required. No. of SS Target date of   removal of deficiencies.

FORMAT ‐2 ( REVIEW OF ZONE ‐ 3 PHILOSOPHY)

WRPC

Constituent \ kV 765 400 220 Total 765 400 220 Total 765 400 220 Total 765 400 220 TotalMahaGuj 92 92 92 NACG

MPPGCL 2 4 2 4 0 1 15.08.2013MPPTCL 5 54 5 54 5 54MP 7 58 7 58 5 55

WR‐I (PG) 3 9 0 3 9 0 3 9 0 NA NA NA NAWR‐II (PG) 14 14 14WR‐I (NTPC)WR‐II (NTPC)

No. of sub‐stations covered at each voltage 

level.

No. of S/S where revised Z‐III setting have been 

implemented.

Month and year by when revised Z‐III settings would be 

implemented at remaining sub‐station.

Recommendation 9.1.2: Till protection audit is taken up, there is a need to take immediate review of zone 3 philosophy in paticular.  Techniques are available to modify characteristics of the relay so that it can distinguish between load encroachment and faults. These techniques and other alternatives should be explored immediately.                                                                                                                                          Action : RPCs, CTU, STUs.: Time frame : 

Total No. of S/S at 220 kV & above (132 KV & above in NER states, J&K, Uttarakhand, HP, Sikkims, 

etc)

Format 3

No. of PMUs installed  LocationsNo. of PMUs functional and time 

syndchronisedTarget date for making 

defective PMU functionalNo. of PMUs Locations

Target date for commissioning

1

Maha

15

400 kV Chandrapur, Koradi, Bhusawal, New Koyna, Padghe, Dhule, Kalwa, Kolhapur, Aurangabad, Lamboti, Lonikand, Girawali; 220 kV Trombay, Eklahare GCR, Boisar

35 502 Guj 0 25 253 CG 04 MP 05 WR‐I (PG)6 WR‐II (PG) 10 107 WR‐I (NTPC)8 WR‐II (NTPC)

PurposeTrigger for SPS operation

Result of SPS operations

1 Maha2 Guj 63 CG4 MP5 WR‐I (PG)6 WR‐II (PG) 27 WR‐I (NTPC)8 WR‐II (NTPC)

Target date of finalization of

Target date of commissionin

PurposeTrigger for SPS operation

Result of SPS operations

1 GETCOTo restrict overloadding on 220 KV Ukai-Mota- D/C lines at Mota s/s

Stage-1:-700 A, 5 Minutes.Stage-2 : 750 A, 6 sec.

(It will cut off load of 66 KV System at 220 KV Mota and Ambheta S/s)

Operated on 25.5.13…… Recently on 26.06.13, 03.07.13, 10.07.13. To restrict overloadding

of220 KV D/C KAPP-Vapi

line

Under planning NA By end of

October-2013By end of

October-2013

2 GETCO

To restrict loading of 3 nos. of 100 MVA

220/66 KV transformers at Bhilad

s/s.

Stage: 240 A , 5 Sec.

(It will cut of load of 66 KV Bhilad-Silvasa-1 & 66 KV Bhilad-Silvasa-2)

Not operated Yet.

To restrict overloadding of

400 KV S/C Hadala-Jetpur & 400 KV Hadala

-Chorania

Under planning NA By end of

October-2013By end of

October-2013

Purpose of SPS Trigger for SPS operation Result of SPS operations

(details of load shedding / backing down).

Details of SPS being planned / under study

Sr. No. (B) SPS already operational at present SPS Under implementation

S No. Constituent

S No. Constituent

Details of existing PMUs Total No. of PMUs in the State

SPS is already operational at present SPS under Implementation

Additional PMUs planned to be insatlled

Target date of Finalization of 

SPS

Details of SPS Being Planned / Under studyPurpose of SPS Trigger for SPS operation

result of SPS operations (detailof load shedding/backing 

down)

Target date for commissioning 

of SPS

3 GETCOTo restrict overloadding

on 220 KV Amreli-Savarkundla D/C lines

Stage-1:-660 A,10 Sec.Stage-720 A, 1 sec.

(It will cut off load of 66 KV System at 220 KV Savarkundla S/s)

Operated on 31.08.2013.

4 GETCO

To restrict overloadingof 400/220 KV 315 MVA ICT at 400 KV Amreli

S/s

Stage : 400 A , 5 Sec.

(It will cut of load of 66 KV feeders at 400 KV Amreli s/s)

Not operated Yet.

5 GETCO

To restrict the loading on 150 MVA, 220/132 KV

ICT at 400 KV Asoj S/s in case of the sudden

loss of GIPCL generation .

Setting HV current :- 360 ARated HV Current: 394 A

(It will trip 132 KV Asoj-Manjusar line no. 1 &2.

Commissioned on 23/7/13

Operated on 23.08.2013.

6 GETCO

To restrict the loading on 220/132 KV

transformers at 220 KV Jambuva S/s in case of the sudden loss of GIPCL generation .

Setting HV current :- 231 ARated HV Current: 262 A(It will trip 132 KV Karjan,

Tilakwada. 66 KV Dabhoi, 66KV Tarsali 1 &2)

Commissioned on 29/7/13

Not operated Yet.

7 GETCOTo restrict loading of 220 KV Hadala- Nyara 1 & 2

line at Nyara s/s

Setting 720 A, 1 sec.

It will trip breaker of 220 KV Kangashiyali feeder.

Not operated Yet.

8 GETCO

To restrict overloading of 400/220

KV ICT at 400 KV jetpur S/s

Alarm Setting : 408 A , 1 sec. Tripping setting : 430 A, 5 sec.

(It will trip 66 KV feeders at 400 KV Jetpur S/s.)

Not operated Yet.

9 GETCO

To restrict overloading of 400/220

KV ICT at 400 KV Asoj S/s

Setting : 650 A, 5 Sec.(It will shed 66 KV feeders at

Jambuva & Chandrapura S/s using direct trip command.)

Not operated Yet.

10 GETCO

To restrict overloading of 400 KV D/C APL-Sami-Dehgam lines without FSC.

Stage-1:- 500 MW, 10 Sec - AlarmStage-2:- 650 MW, 03 Sec - Tripping of APL Unit No. 3 or 4Stage-3:- 750 MW, 01 Sec - Tripping of one 660 MW Unit.

Most of the time, these lines remain in service with FSC only.

11 GETCOTo restrict overloading of 400 KV D/C APL-Sami-Dehgam lines with FSC.

Stage-1:- 500 MW, 10 Sec - AlarmStage-2:- 750 MW, 03 Sec - Tripping of APL Unit No. 3 or 4Stage-3:- 800 MW, 01 Sec - Tripping of one 660 MW Unit.

Operated successfully many times.Recently operated on 01.06.13 tripping APL Unit No. 4 (running at 235 MW)

12 GETCO

To restrict overloading of 400 KV APL-Varsana & 400 KV APL-Hadala lines

Stage-1:- 500 MW, 10 Sec - AlarmStage-2:- 750 MW, 03 Sec - Tripping of APL Unit No. 3 or 4Stage-3:- 850 MW, 01 Sec - Tripping of one 660 MW Unit.

13 GETCO

To restrict overloading of 220 KV D/C APL-Nanikhakhar & 220 KV D/C APL-Tappar lines

Stage-1:- 500 A, 05 Sec - AlarmStage-2:- 550 A, 02 Sec - Tripping of any one 400/220 KV, 315 MVA ICT at APL Stage-3:- 605 A, 05 Sec - Generation backing down.Stage-4:- 670 A, 02 Sec - Tripping of APL Unit No. 1 or 2.

SPS has operated successfully.

14 WR II

Gwalior S/S - 765kV Gwalior-Agra ckt.1 & 2 - For Load Shedding in Northern Region

15 WR II

Gwalior S/S - 220kV Gwalior(PG)-Gwalior(MP) & Malanpur-For Tripping of 220kV Lines at Gwalior (PG) S/s in case of tripping of 765kV lines

16 SPS at LANCO-Pathadi

When 400kV Pathadi-Raipur trips, I unit of 300MW of LANCO has to be tripped.

commissioned in Aug 2010 M/s LANC

17 SPS at JPL-Tamnar

If one ckt of 400kV Tamnar-Raipur trips, iunit of 250MW will trip and other 3 units would reduce by 60MW as one coal mill trips. When DCPP units are on bar, 220kV DCPP-JPL line will also trip.

commissioned in Sept 2011 M/s JPL

18 SPS at APL-Mundra

Details of the scheme at 400kV and 220kV are given as Annex-I

commissioned in Aug 2011 M/s APL

19 SPS at HVDC , APL,Mundra

Details of the scheme are given as Annex-II

commissioned in July12 M/s APL

20SPS for tripping of Agra-Gwalior-Bina lines

Sudden reduction of import by NR due to tripping of Agra-Gwalior I& II , a total of 500MW backing down in Western Region automatically in Korba,Vindhyachal,Sipat, CGPL & JP Bina.

Proposed POWERG

21 SPS at BALCO

If 400kV Balco- Birsighpur trips, Balco to reduce generation to 100MW. If 400kV Balaco-Birsinghpur flow is more than 550MW, Balco to reduce generation by 100MW.

Proposed M/s BALC

22 SPS at Korba Complex

Total flow on Korba(E)-Raigarh + Korba(W)-Kotmikla<525MW . Details given in Annex-III.

Proposed CSPTCL

23SPS at 765kV Sipat Power Station

Tripping of 765kV Seoni-Bilaspur D/C. Details given in Annex-III

Proposed NTPC

24 SPS for CGPL In Annex-IV Proposed CGPL

25 SPS for Wardha Flow gate Proposed MSETCL

Format ‐ 4 (Enabling UFR and df/dt relay)Action: STUs, RPCs, Posoco, Time frame: immediate

No.Target date of commissioning

Maha 272 271 0Guj 149 145 0CGMP 278 278 0OSP 13 13 0

12 12 0WR‐I (PG)WR‐II (PG)WR‐I (NTPC)WR‐II (NTPC)

No.Target date of commissioning

Maha 30 30Guj 149 145 0CG

MPPGCL 32 32 0 1 Oct‐13OSP 13 13 0ISP 12 12 0MP 57 57 0 1

WR‐I (PG)WR‐II (PG)WR‐I (NTPC)WR‐II (NTPC)

C. Petitions 

POSOCO (Petition wise)

In detailS.No.  Petitioner Respondent Presently case is with Allegation Amount claimned Status of Proceeding Brief of the case

1 BSP/NSPCL WRLDC Central Electricity Regulatory Commission

The arbitrary action of Western Regional Load Despatch Centre by loading

transmission losses on the 220kV lines being used for transfer of power from generating

station of NSPCL to Bhilai Steel Plant

No amount is to be paid or received by Power Grid /

POSOCO

The case was heard once, affidavit is being filed by WRLDC&NLDC by

11.05.2012. The last hearing held on 16.05.13

The arbitrary action of Western Regional Load Despatch Centre by loading transmission losses on the

220kV lines being used for transfer of power from generating station of NSPCL to Bhilai Steel Plant.

Final order from CERC is still awaited.

2 Adani Power LtdNLDC/PGCIL/NRLDC/

WRLDC/CEA/GECTO/HVPNL/

Central Electricity Regulatory Commission NIL

No amount is to be paid or received by Power Grid /

POSOCO

Four Hearing over , finle order pending Last hearing held on 16.05.13.

Seeking grant of transmission license under Section-14 read with section 15(1) of the Electricity Act,2003

and CERC (Procedure,Terms and Conditions for grant of Transmission Licence and other related

matters) Regulation 2009

1. PTC India Ltd.

2. HPGCL3. Chhattisgarh State Power Trading Co. Ltd.4. Western Regional Load Dispatch Centre5. Central Electricity Regulatory Commission1.Haryana Electricity Regulatory Commision2.WRLDC3.CSPTCL

Case pending Dispute over termination of PPA/revision of tariff/APTEL order

Application to fix/approve tariff for sale and purchase of power for the dispute period from Unit-2 of Lanco

Amarkantak Power Ltd. to PTC as per Hon’ble Supreme Court Order dated 16.12.2011. Currently

stay by Supreme Court

4

3

Supreme Court of India

HERC NIL Supreme Court stayed the proceedings at HERC

NIl

No amount is to be paid or received by Power Grid /

POSOCO

No amount is to be paid or received by Power Grid /

POSOCO

No. of petitions filed ‐ 17

HERC/PRO-01 of 2012

Civil Appeal.No.10329/2011

Lanco Amarkantak Power Ltd.

Lanco Amarkantak Power Ltd.

Pending

Petition No.

Petition.No.211/MP/2011

Petition.No.44/TL/2012

No. and details of petitions filed with CERC for non‐compliance of various regulations, issued under 

the act, by the statesBrief of petitionfiled in CERC  Status of Petition

No. of UFRs functional

Total No. of UFRs 

installed 

RPC (State) 

Total No. of df/dt relayss installed 

No. of df/dt relays 

functional

A. State wise details of UFR (as on date                                     )

Details of additional UFRs under implementation/planned

Details of additional df/dt relays under implementation/planned

B. RPC (State)State wise details of df/dt (as on date )

 month and year to complete the remedial 

action

action being taken to make them functional

No. of UFRs nonfunctional

No. of df/dt relays nonfunctional

action being taken to make them functional

 Month and year to complete the remedial 

action

4.Union of India, Ministry of Law1.Dakshin Gujarat Vij Co.Ltd.2.SLDC,Gotri,Vadodara3.NLDC,New Delhi4.NRLDC, New Delhi5.WRLDC, Mumbai6.ESSAR Electric Power Development Co.Ld

6

EMCO Energy Ltd,KSK

Mahanadhi Power Co.Ltd

WRLDC, POSOCO CERC Direct WRLDC to allow the petitioner to draw commsiioning power under UI

No amount is to be paid or received by Power Grid /

POSOCO

1st hearing held on 6th Jan 2012. Next hearing scheduled on 16th July'2013

Hon'ble CERC through its order dated 2nd Nov'2012 in petition no 1178/MP/2012 has directed to delete

the line"including drawal of power for commissioning activities" fro approved procedure. Accordingly

WRLDC has asked all the generators in WR who are under going the commissiong activities to stop drawigpower through UI and asked to arrange for any form of open accesss in accordance with the commissions

directions.

1. WRLDC, POSOCO

2.SLDC,Gotri,Vadodara3.PGCIL,Gurgaon 3.MSEDCL,GUVNL,DGVCL,MPPTCL,CSPDCL and others.

8 Jindal Power Ltd 1.NLDC 2.WRLDC 3.PGCIL CERC

Petition under Sec 79(1) ( C ) and 79 (1) (k) of EA-2003 for directions to accept

schedules for supply of power against LTA.

No amount is to be paid or received by Power Grid /

POSOCO

NLDC & WRLDC jointly submitted the reply on 15th Nov'2012, two hearings are

over on 22nd Nov'12 and 13th Dec'12, 31st Jan'13 , 12th Mar'13 & 16th May'13

JPL wanted to give directions to WRLDC & NLDC for the STOA may be given 1st prefernce against

their LTA of 500MW. Final order is awaited.

9Chhattisgarh State Power Distribution

Co.Ltd

1.Madhya Pradesh Powe Management Co.Ltd 2. WRLDC 3.WRPC

CERC

Non payment by MPPM Co.Ltd for the Var exchange between CSPDCL and MPPM

co.ltd thorugh the inter state lines owned by them.

No amount is to be paid or received by Power Grid /

POSOCO

Hearng were held on 11th Dec'12 and 2nd hearing is on 17th Jan'13, 3rd hearing on

12th Feb'13 and 4th hearing on 9th Apr'13. Next hearing on 27th Jun'13

The Var charges for the Var exchange between two regional entities through inter state line owned by

them need to be settled mutually as per IEGC-2010. MPPGCL is not making the above payment to CSPDCL wef April 2006.Final order awaited.

10 WRLDCAll the entities who are under the control area jurisdicion of WRLDC

CERCEnforcing adequate frequency

response from control areas in Indian Grid

No amount is to be paid or received by Power Grid /

POSOCO

Hearing conducted on 12/04/12 & 07/06/12. Order issued on 3rd April

2012

Stringent enforcement of the primary response from genertors through RGMO/FGMO with no excemption to any generators and monitoring of control area wse

fquency response for all events involving a sudden 1000MW load/generation loss thorough periodic reports submitted by control areas, SLDCs and

RLDCS to Commission. Final order given by CERC

11 WRLDC All SLDCs and STUs of W CERC

‘‘Maintaining security of the interconnected power system of India in terms of regulation 5.2 of the Indian Electricity Grid Code and

compliance of regulation 5.4.2 & 6.4.8 of the IEGC read with regulation 111 of the CERC

(conduct of Business) regulation, 1999’’

No amount is to be paid or received by Power Grid /

POSOCO

1st hearing held on 8th Jan'2013, 2nd hearing on 5th March 2013

‘‘Maintaining security of the interconnected power system of India in terms of regulation 5.2 of the Indian Electricity Grid Code and compliance of regulation 5.4.2 & 6.4.8 of the IEGC read with

regulation 111 of the CERC (conduct of Business) regulation, 1999’’ . Order against hering on 8th Jan'13

i d 14th J '13

12 7/Suo Motu/2012 Suo Motu by CERC

NLDC/PGCIL/NRLDC/WRLDC/ERLDC/NERLDC/NRPC/WRPC/ERPC/NERPC/NTPCCEA/GECTO/HVPNL/

CERC Grid disturbance on 30th & 31st July 2012.No amount is to be paid or received by Power Grid /

POSOCO

1st hearing was held on 27th Nov'2012/2nd heariing was held on 10th Jan 2013 & 3rd hearing was held on 20th

Feb'13

NR grid failed on 30th July 2012 and NR,ER & NER grid collapsed on 31st July'12. CERC issued an Suo Motu to hear the views, factors which precipitataed the grid failure and remadial measures which need to be taken to avoid such instances in fuure. Final order

1. PTC India Ltd.2. HPGCL3. Chhattisgarh State Powe4. Western Regional Load 5. Central Electricity Regu

ESSAR steel India wants that the power drawn during the grid disturbance period to be treated as UI power by DGVCL and to with draw the maximum demand charge imposed by DGVCL on ESSAR steel India.

13

5

7

APTELQuashing of Order dated 17th Oct'2012

passed by HERC in Case No.HERC/PRO-1 of 2012

Hearing scheduled on 18th April'13Quashing of Order dated 17th Oct'12 passed by

HERC in Case No.HERC/PRO-1 of 2012 , section 111 of EA-2003

ESSAr Steel India ltd has wants to shift the control area jurisdiction from SLDC, Gotri to WRLDC

Mumbai. Since the present IEGC clause is silent on shifting of bulk consumers , WRLDC did not agree for the proposal and requested ESSAR Steel to take

up the matter with CERC. As per CERC order control area shifted from SLDC, Gujarat to WRLDC.

Hearings were held on 27th Nov'2012.& on 17th Jan'2013. Last hearing held on

16th May 2013. Order issued on 8th June 2013.

Direct WRLDC to transfer control area jurisdiction of ESSAR Steel India Ltd from

SLDC to WRLDC

To withdraw the maximum demand charge imposed by DGVCL / No intimation given by WRLDC/NRLDC on revision of STOA schedules on 30th & 31st july'2012 due to

grd disturbance

Case admitted on 24/09/12, hearing last hearing held in June.Order pending with

GERC.

No amount is to be paid or received by Power Grid /

POSOCO

No amount is to be paid or received by Power Grid /

POSOCO

Lanco Amarkantak Power Ltd.

No amount is to be paid or received by Power Grid /

POSOCO

Appeal No.65 of 2013 & IA Nos.103,104& 105 of

2013.

244/MP/2012

193/MP/2012

51/MP/2012

264/MP/2012

259/MP/2012,27/RP/2012

1259/2012

245/MP/2012

ESSAR Steel India Ltd.

ESSAR Steel India Ltd. CERC

GERC

14Suo Motu by

CERC71 respondents all over India CERC Non compliance of Commissions direction

dt. 26th Sept'12 in Pet.No.168/MP/2011

No amount is to be paid or received by Power Grid /

POSOCO

Hearing held on 11th Apr'13. Last hearing held on 20th June 2013

for establishment and maintenance of Communication facilities by the USERS of the Western Region in terms of Clause 4.6.2 of IEGC, 2010, read with Clause 5(3) of CEA (Technical Standards for

Connectivity to the Grid) Regulation, 2007 to ensure availability of reliable real time data at WRLDC.

15 WRLDCSASAN, IE, 14 beneficiaries of SASAN UMPP

CERC Declaration of CoD by SASAN UMPP at a derated capacity

No amount is to be paid or received by Power Grid /

POSOCOAdmission hearing over.Order awaited. Declaration of CoD by SASAN UMPP at a derated

capacity

16 CSPDCL PGCIL,POSOCO,WRLDC CSERCReactive Energy Charge dispute between

CSPDCL & MPPTCL on REC charge between stae owned lines.

No amount is to be paid or received by Power Grid /

POSOCO

Amission hearing over. Next hearing is on27th July 2013

Reactive Energy Charge dispute between CSPDCL & MPPTCL on REC charge between stae owned lines.

17 NTPCWRPC,WRLDC all beneficiaries of NTPC in WR

CERC Scheduling under fuel shortageNo amount is to be paid or received by Power Grid /

POSOCO

Admission hearing over, reply submitted by WRLDC

Dispute between NTPC & WR beneficiaries on scheduling under fuel shortage conditions.

Pet.No 56/SM/2013

Pet.19/2013(M)

Pet.No.114/MP/2013

Pet.No.85/MP/2012

Format ‐5 Real time Security Desk

POSOCODetails of real time security desk at each RLDC and NLDc

Details of outage scenarios built to be used by despatcher in real time for revising TTC calculations

Status of development of faster algorithm for for real time updation of TTC calculations by load despatcher under outage conditions

Provided in WRLDC control room

Action: Posoco, Time frame: 6 months

 FORMAT ‐ 6 (ADUIT OF HVDC, TCSC SVC AND PSS TUNING)

Location of HVDC Audit status (completed on 

dd/mm/yyyy)rvations of the aduit and the name of audit ag

Action plan with timeline to remove deficiencies as per 

audit.MahaGujCGMP

WR‐I (PG)                BHADRAVATI HVDC     

Back to Back22.01.2013 WR‐II and WRLDC Representative No discrepancy Found.

WR‐II (PG)WR‐I (NTPC)WR‐II (NTPC)

 Location of TCSC Audit status (completed on 

dd/mm/yyyy)rvations of the aduit and the name of audit ag

Action plan with timeline to remove deficiencies as per 

audit.MahaGujCGMP

WR‐I (PG) Raipur TCSC 06.02.2013 WR‐II and WRLDC Representative No discrepancy Found.WR‐II (PG)WR‐I (NTPC)WR‐II (NTPC)

 Location of SVC Audit status (completed on 

dd/mm/yyyy)rvations of the aduit and the name of audit ag

Action plan with timeline to remove deficiencies as per 

audit.MahaGujCGMP

WR‐I (PG) NA NA NA NA

WR‐II (PG)

WR‐I (NTPC)

WR‐II (NTPC)

(B) Audit of TCSC

 (A) Audit of HVDC

Recommendation: 9.9.2.: An audit of devices such as HVDC, TCSC, SVC and PSS should be done immediately to enusre that their  stability features are enabled. Further exercise of PSS tuning should be planned and implemented. Settings of these dynamic stabilizing devices should be reviewed at appropriate intervals.               Action :  CTU, STUs, Generators: Time  Frame : 6 months.

(D) Status of PSS Tuning

( C)  Audit of SVC

RPC (state wise) Name and Location of 

generator identified for PSS tuning.

 Audit status (completed on dd/mm/yyyy)

Action plan with time line to complete PSS tuning.

Maha 23GujCGMPOSP 1ISP 1

WR‐I (PG) NA NA NA NAWR‐II (PG)WR‐I (NTPC)WR‐II (NTPC)

Format‐7 Voltage collapse prediction relayAction: RPCs, Time Frame: 1 year

Status of exploration of voltage collapse prediction relay

In Boisar,  A‐eberle collapse prediction relay was installd on 17.10.2012 as a demo project. Currently, offline analysis is carried out by WRLDC regularly and exploring the 

opportunities to integrate with real time visualization softwareWRLDC

Format‐8 Telemetry facilities

POSOCO (Region/State/CPSU wise)

Fault in telemetry / reason for non‐availability of telemetry

Nature of communication link for required telemetry in column (A) (Micro wave /fibre/PLCC etc..,)

Action plan with time line to operatiionalize the required telemetry facility

GETCOMPPTCLMSETCLCSPTCLGoaDDDNHTotal

Name and location of Generating station / transmission element without telemetry 

facility 17854111284

Action: RPCs, Posoco, Time frame: 6 months

Description

Total No. units/stations in the region

Units required co operate under RGMO/FGMO as per IEGC

Units operating under RGMO

Units operating in FGMO with manual intervention to archive RGMO

Total No. of units under FGMO/RGMO (4+5)

Units Exempted from FGMO/ RGMO by CERC

Units applied to CERC for exemption/ extension

Units operating with locked governors

Units whose status is not available

Remarks

especially regarding entries, if any, in column (9) or (10)

1 2 3 4 5 6 7 8 9 10 11No. of Units (CS) 47 29 18 18 5 6No. of Units (SS) 254 126 29 29 8 89No. of Units (Pvt sector) 90 42 37 37 0 5No. of Stations (CS) 12 4 2 2 0 2No. of Stations (SS) 83 46 10 10 2 34

No. of Stations (Pvt sector) 33 12 8 4

Installed capacity CS (MW) 16211 7810 5460 5460 250 2100Installed capacity SS (MW) 29943 16155 4220 4220 540 11395Installed capacity FS (MW) 20598 13916 12766 12766 0 1150

Format-09STATUS OF OPERATION OF POWER STATIONS UNDER FGMO/RGMOAs on

Name of Region:

It has been reported that there are problems 

associated with governors of the units indicated in column 9

1

Baart sarkarGovernment of Indiakond`Iya ivaVut p`aiQakrNa

Central Electricity AuthoritypiScama xao~Iya ivaVut saimait

Western Regional Power Committeeef -3, emaAayaDIsaI xao~, AMQaorI (pUva-), mauMba[- - 400 093

F-3, MIDC Area, Andheri (East), Mumbai - 400 093

Aa[- esa Aao : 9001-2008IS/ISO: 9001-2008

dUrBaaYa Phone: 022- 28209506, 28200195; 28200196; fO@sa Fax : 022 – 28370193Website : www.wrpc.gov.in E-mail : prc-wrpc@nic.in ; protectionwrpc@gmail.com

NO. WRPC/Protection/2013-14/ Date: 25.02.2014

To,

CEO, POSOCO,B-9, Qutab Institutional Area,Katwaria Sarai,New Delhi -110016

Sub: Concerns regarding frequent operation of SPS for 765kV Sholapur Raichur line andsynchronous operation of SR-NEW grid-reg.

NLDC had formulated various SPS schemes in WR for synchronization of SR with NEW grid throughsingle circuit of 765kV Sholapur-Raichur by considering anticipated contingencies. The same was put intoservice by all the WR constituents before synchronization of SR with NEW grid.

A meeting was held on 17.12.2013 at WRLDC (MoM is enclosed at Annexure-I) to discuss thepreparedness of WR constituents prior to synchronization, wherein concerns were raised by constituents ofWR. However in view of importance of the event of synchronization of SR with NEW grid, theconstituents were requested to implement the SPS as formulated by NLDC and subsequently the samecould be reviewed after the stable operation of the All India grid. It was also decide to review the schemesin Feb.2014, after about a months of operational experience. NLDC and CTU representatives were alsopresent in the meeting.

It is to inform that the experience of post synchronization operation of All India grid was discussed in the25th WRPC meeting held on 03-04.02.2014 at Lavasa city Lonawala. Inter alia, the performance of the SPSafter 31.12.2013 (i.e. after synchronization of SR & NEW grid) was also discussed in OCC, PCM andsubsequently in TCC/WRPC meeting on 03rd & 04th Feb. 2014 at Lavasa. The concerns raised byconstituents due to frequent operation of the SPS are enclosed at Annexure.-II. The outcome of thediscussions is summarized as follows:

A : Issues observed in real time operations by WRLDC;

1. Variation in line flow on 765 kV Sholapur-Raichur from +800MW to -600MW.

2

2. Frequent HVDC set-point toggling and STOA Curtailments3. Sudden increase in flow on 765kV Raichur-Sholapur flow leading to SPS operation.4. Frequent synchronization & de-synchronization5. 5th harmonic increase observed at Bhadrawati.6. Dominant mode of oscillations observed after synchronization is 0.22Hz, with damping ratio of 0.11.Subsequently the oscillations died out after 17secs. The 0.2Hz oscillations were observed during theperiod the tie line flow was above +800MW.7. Receipt of both SPS tripping signals (S1/S2), when only one signal should have operated etc was notedin PCC.

B : Issues of generators participating in SPS;

As far as SPS schemes concerning tripping of generators, concerns were already raised in the meeting heldon 17.12.2013 and summarized as follows;

1. Amounts to entire station tripping ( in case of JPL, KSK Mahanadi & NTPC Mauda).2. Need for sharing the burden with other generators in that area.3. Mal operation of SPS : Receipt of higher (S2) signal when only S1 was required.4. Commercial issues such as curtailment of STOA’s in W-3 bid area

C : Operation of SPS :The SPS operations for different criteria’s (summary SPS operation is enclosed at Annexure-III) is asfollows :1. SPS_Wardha-Parli powerflow > 750 MW : 21, 23, 24, 25 January2. SPS_Sholapur-Raichur powerflow > 800 MW : 2, 3, 4, 7 (Thrice), 22, 26, 30 January3. Loss of import at Sholapur > 800 MW : 2, 7 January4. Rate of change of power on Sholapur-Raichur > 400 MW/sec : 27 (twice), 28 (twice) January5. False signal : 31 December, 6, 25 JanuaryD : Issues that are required to be addressed;1. The flow limits on the basis of which SPS have been formulated by NLDC needs to be clarified. It isnot clear whether these limits are the ATC/TTC capabilities for scheduling commercial transactions or thetechnical limits for operation of SPS. Therefore assumptions made / studies carried out may be shared.2. Frequent operation of SPS suggests that it needs to be ascertained whether violation of these flowlimits (SPS operation events) have resulted in violation of the system parameters beyond prescribed limitsduring real time. It needs to be shared, whether, on operation of SPS and subsequent backing down of thegeneration, there is improvement in the deteriorated system parameters. This would validate the studyresults as against the actual flows and system parameters observed/noted during the SPS operations.3. There is a need to reduce the quantum of backing down to realistic and safe levels. This would reduceperturbations in the operating point, particularly in view of low frequency oscillations observed. Thereforeit is felt that the generation backing down quantum needs to be reduced, with only one SR-WR link.Further, identification of the generators for backing down shall be based on sensitivity of the generators tothe flows identified as contingencies.4. Four generating stations have been identified in SPS for backing down/tripping of units for variouscontingencies viz. JPL, KSK Mahanadi, Adani Power Tiroda and NTPC Mauda. Since generation at DBPower is not declared into commercial operation, it has been excluded from the SPS. In real time the on bar

3

generation at these stations in most of the time is not at their full capacity, therefore to achieve the quantumunder relief the units have to be tripped. Therefore more generating stations in the ER-WR-SR corridor,particularly generators in W-3 bid area, are required to be identified so that the quantum of relief could bedistributed among these generators such that unit/station tripping is avoided and the relief could beobtained through automatic backing down of generation. Further it is suggested that the backing downquantum could be distributed within group of generators and/or the groups may be put under backing downin a round robin fashion, so that the generators can plan/schedule their generation with certainty.5. Mal-operation of SPS due to false signals (higher signals) transmitted to generators requires to beaddressed.6. Commercial issues such as curtailment of STOA’s in W-3 bid area due to this additional linkconnecting SR-NEW grid needs to be addressed.7. The generators for SPS need not be based on whether the generator has been granted LTA/MTOA, butrather it should formulated such that the generation online should be curtailed irrespective of itsLTA/MTOA on technical grounds and effectiveness of backing down. The injection of generators sellingthrough STOA shall be regulated as per the grant of LTA/MTOA regulations in real time manually as afirst step, and the SPS action shall be allowed to take over only after taking all such manual measures asper the regulations in force. In short the system operator shall first exercise its role to control the injectionsas per regulatory provisions and not shift its role to SPS and SPS shall take over as the last resort.

8. There is a large variation in flow on the tie line in either direction. Even small variations in the loads ortripping of lines/generators in either side of the tie line may trigger inter-regional oscillations of the order0.2 to 0.8Hz. If these oscillations are not damped out, lines adjacent to the tie line may trip on powerswing/load encroachment. This may cause separation of SR from All India grid. Due to this large variationon the tie line flows and subsequent tripping of the tie line on over load may trigger intra-regionaloscillations in the separated NEW and SR grid. This may lead to tripping of other lines on powerswing/load encroachment in the respective regions, if the oscillations are not damped out. Further trippingof a 765kV tie line on over load (current) is never designed in the protection system. Therefore tripping oftie line on over load (current) may be reviewed.

In spite of the above concerns, all the measures suggested by NLDC have been implemented. Now, havingan experience of single line synchronous operation of SR-NEW grid, it is felt that the concerns are genuineand needs to be addressed, by giving proper justifications to the measures suggested.

It is therefore requested that the SPS formulated by NLDC may be reviewed based on the operationalexperiences during the synchronous operation and share the study results and assumptions made thereofwith the WR constituents.

Yours’ faithfully,

Sd/-

S D Taksande,Member Secretary

HCL

Text Box

Annex-7.2

Page 1 of 10

Revisions in System Protection Schemes(SPS)-NEW & SR grid synchronisation

(part of NLDC communication NLDC/SR_synch_SPS/ dated 11th April 2014)

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

1  765kV Sholapur‐Raichur flow > 800 MW: SPS‐1  Total flow on 765 kV Sholapur‐Raichur 2 x 765  kV  S/C  lines  crossing  a  preset  value, say  800  MW  in  Sholapur  to  Raichur direction  sensed  both  at  Sholapur  and Raichur.  

Western Region  500MW Gen Back down JPL ‐ 350MW KSK ‐  150MW DB power=0  Southern Region 500 MW Load Shedding Tamilnadu‐            146MW Kerala ‐                   125MW Karnataka‐             104MW Andhra Pradesh    125MW 

Suggestion:  SPS  should trigger when   flow on 765 kV Sholapur‐Raichur  S/C  line crosses  1000  MW  and remains  above  1000 MW  for 2.5 seconds.  It  should  also  act instantaneously  when  the power  flow  crosses  1500 MW.  Western Region  800 MW Gen Back down More  generators  such  as Lanco  Amarkantak,  KWPCL, BALCO,  JPL  Ext,  NSPCL  etc. must  be  covered  in W3  area so  that  800  MW  relief  is available under all conditions. Southern Region  No Change 

 Rationale:  SPS  should  not operate  for  the  first  swing arising  out  of  generating  unit trip  in  Southern  Region  and antecedent  flows  from Sholapur  to  Raichur  is  less than,  say  400‐500  MW, towards  Southern  Region.  It has  been  observed  from synchrophasor  data  that  the first  spike  is  typically  115‐125% of the generation  lost  in Southern  Region  and oscillations  of  the  order  of 0.20 Hz are observed.  Further,  one  argument  cited by  generators  towards inadequate  relief  is  the  low antecedent  generation  on these units. As this would be a highly  probable  scenario,  SPS wiring may be done  for more quantum  so  that  800  MW 

Page 2 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

relief is always available.   

 2  Rate of change of flow >400 MW/Sec: SPS‐2 Rate  of  change  of  flow  crossing  400 MW/second  in  the  Sholapur  to  Raichur direction.  

   

Same as above 

Suggestion:  Pending  a clarification  by  POWERGRID as  to  how  dP/dt  is  actually computed  at  field  level,  this setting  may  be  blocked temporarily.  

The  logic  for computing dP/dt needs  to  be  clarified  by PowerGrid  as  it  is  observed from  synchrophasor  data,  it appears  to  have  been activated at lower values also.  

3  SPS for Loss of 800 MW import by SR: SPS‐3 Loss of import on 765 kV Sholapur‐Raichur by more  than 800 MW due  to  tripping of these lines. 

   

Same as above 

 Suggestion:  In case of  loss of import  on  765  kV  Sholapur‐Raichur  by  more  than  800 MW due  to  tripping of  these lines,  only  load  shedding should  occur  in  SR.  Tripping or  backing  down  of generators may therefore be blocked.   

 Rationale:  Load  Generation balance  in  NEW  grid may  be taken care by governor action. In  SR,  to  arrest  a  sharp frequency  fall,  load  shedding through SPS is required.  

Page 3 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

4  400 kV Raipur‐Wardha :   SPS‐4

Flow on 400 kV Raipur‐Wardha any circuit crossing  800  MW  sensed  at  Raipur  OR tripping  of  any  one  circuit  of  400  kV Raipur‐Wardha  carrying  650  MW  or above. 

Western Region  800MW Gen Back down JPL ‐ 600MW KSK ‐  200MW DB Power – 0 MW  Southern Region  800MW Load Shedding (Kudankulam group) Tamilnadu‐            290MW Kerala ‐                   135MW Karnataka‐             195MW Andhra Pradesh    230MW 

Suggestion:   Triggering  point  may  be modified as  ‘antecedent  flow on  either  of  the  400  kV Raipur‐Wardha  circuit crossing  850  MW  and remaining  above  this  value for 2.5 seconds OR tripping of any  circuit  when  the antecedent  flow  is  greater than 700 MW.  Western Region  800 MW Gen Back down More  generators  such  as Lanco  Amarkantak,  KWPCL, BALCO,  JPL  Ext,  NSPCL  etc. must  be  covered  in W3  area so  that  800  MW  relief  is available under all conditions.  Southern Region  No change  

  Rationale:  To  take  care  that there  is  no  SPS  action  in  the first  spike  following  a  large event.  Further,  one  argument  cited by  generators  towards inadequate  relief  is  the  low antecedent  generation  on these units. As this would be a highly  probable  scenario,  SPS wiring may be done  for more quantum  so  that  800  MW relief is always available.  

Page 4 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

5  400kV Wardha‐Parli  line  : SPS‐5 

Flow  on  400  kV Wardha‐Parli  any  circuit crossing  750 MW  or  tripping  of  any  one circuit  of  400  kV  Wardha‐Parli  section carrying  600  MW  or  above.  Sensed  at Wardha. 

Western Region APL Tiroda ‐ 600MW NTPC Mauda ‐  200MW IEPL – 0 MW   Southern Region  800 MW Load Shedding (Kudankulam group) Tamilnadu‐            290MW Kerala ‐                   135MW Karnataka‐             195MW Andhra Pradesh    230MW 

Suggestion:  The  triggering  point  for steady  state  loading may  be revised  to  the  flow  crossing 850 MW  each  circuit  with  a delay  of  2.5  seconds  OR tripping  of  any  circuit  when the  antecedent  flow  is greater  than  750  MW.  Flow may  be  sensed  at  Wardha end.  Western Region  800 MW Gen Back down More  generators  such  as Koradi,  Khaperkheda, Chandrapur,  Indiabulls  need to  be  covered  so  that  800 MW relief is always available.  250 MW load shedding in Maharashtra west of Sholapur.  Southern Region  No change; however position can  be  reviewed  once 

 Rationale:  Time  delay required  to  take  care  of  the first  spike.  Further,  Wardha‐Parli  line despite having Quad Moose  conductor  is  334  kms. long  and  any  tripping  of  one line when the antecedent flow is more than 750 MW leads to the  angular  separation between  Wardha  and  Parli crossing  30  degrees.  Without automatic  corrective  action, oscillations will not subside as per simulations.  The second unit at Mauda and the  fourth unit at Tiroda have been  synchronized  and declared  under  COD  recently. These  had  not  been  assumed in the initial studies.   SLDC  Maharashtra  shall regulate  load/generation  in Maharashtra  whenever  total power  flow  on  Wardha flowgate  (400  kV  Wardha‐Akola  D/C  +  400  kV Wardha‐

Page 5 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

Maharashtra  implements 250  MW  load  shedding suggested above  

Parli D/C) crosses 2480 MW.  Power  order  on  HVDC Chandrapur‐Padghe  bipole shall also be maximized.  Further,  to  ensure  that  800 MW reduction in generation is achieved,  more  generators need to be covered  in eastern Maharashtra.  NTPC  Mauda relief  is  generally  negligible and  the  station  schedule  is also generally low.   The loading on Wardha‐Parli is sensitive  to  both  western Maharashtra  load  as  well  as Southern  Region  load;  hence load  shedding  is also  required to  be  done  in  western Maharashtra.  

6  400 kV Parli‐Sholapur : SPS‐6 

 Antecedent  flow  on  any  circuit  crossing 800 MW or  tripping of any one  circuit of Parli‐Sholapur carrying 600 MW or above. 

Load shedding by Maharashtra to be implemented.  300 MW generation pick up at Koyna  

Suggestion:  The  triggering  point  for steady  state  loading may  be revised  to  the  flow  crossing 800 MW  each  circuit  with  a delay  of  2.5  seconds  OR 

Rationale:  2.5  seconds  delay to  take  care  of  the  first  spike not leading to SPS action.   

Page 6 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

Sensed at Sholapur. 

800 MW Gen Back down JPL ‐ 600MW KSK ‐  200MW DB Power – 0 MW  Southern Region 800 MW Load Shedding (Kudankulam group) Tamilnadu‐            290MW Kerala ‐                   135MW Karnataka‐             195MW Andhra Pradesh    230MW 

tripping  of  any  circuit  when the  antecedent  flow  is greater  than  600  MW.  Flow may  be  sensed  at  Sholapur end.  Western Region 800 MW Gen Back down More  generators  such  as Lanco  Amarkantak,  KWPCL, BALCO,  JPL  Ext,  NSPCL  etc. must  be  covered  in W3  area so  that  800  MW  relief  is available under all conditions. 250  MW  load  shedding  in Maharashtra  west  of Sholapur.   Southern Region No change; however position can  be  reviewed  once Maharashtra  implements 250  MW  load  shedding suggested above 

 

Page 7 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

7  765kV  Raichur‐Sholapur  line current  exceeding  800  Amp (1000 MW  on  either  direction): SPS‐7 

 

Tripping  of  765kV  Raichur‐Sholapur  line  with  10  seconds delay. 

No  change  suggested  for  the Sholapur  to Raichur direction which is retained at 1000 MW with ten (10) seconds delay.  Ordinarily SPS‐1 action should prevent  this  situation  from arising. In the eventuality that SPS‐1  does  not  act  and  this SPS  operates,  SPS‐3  above should act.  Tripping  of  765  kV  Sholapur Raichur  on  SPS  due  to  the >1000  MW  flowing  in  the reverse  direction  i.e.,  SR  to NEW grid may be blocked.  This  setting  would  be reviewed  with reinforcements  in  the upstream  and  downstream network.  

Rationale:   This  setting  was  decided considering  that  SR  could safely withstand the 1000 MW loss of import or export.  Sustained  operation  above 1000 MW  in  the  Sholapur  to Raichur  direction  would indicate  that  the  upstream and  downstream  systems  are stressed  and  therefore  SR system needs  to be separated through  tripping  of  765  kV Sholapur‐Raichur.  For  the  reverse  direction,  the possibility  of  S1  and  S2  areas getting  separated  due  to  a contingency  is  credible.  There would be a sudden increase in flow from Raichur to Sholapur. Tripping  765  kV  Sholapur‐Raichur  under  these circumstances  may  further worsen  the  situation  in  S1. Hence  this  is  proposed  to  be blocked. 

Page 8 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

 

8  400  kV  Hiriyur‐Neelamangala:SPS‐8 Tripping  of  one  of  the  400kV  Hiriyur‐ Neelamangala DC  line and  Flow on other line > 850 MW  

Western Region  500 MW Gen Back down JPL ‐ 350MW KSK ‐  150MW DB power=0  Southern Region  500 MW Load Shedding Tamilnadu‐            146MW Kerala ‐                   125MW Karnataka‐             104MW Andhra Pradesh    125MW  

 Western Region  800 MW Gen Back down More  generators  such  as Lanco  Amarkantak,  KWPCL, BALCO,  JPL  Ext,  NSPCL  etc. must  be  covered  in W3  area so  that  800  MW  relief  is available under all conditions.. Southern Region  No change 

Rationale: One argument cited by  generators  towards inadequate  relief  is  the  low antecedent  generation  on these units. As this would be a highly  probable  scenario,  SPS wiring may be done  for more quantum  so  that  800  MW relief is always available.  

 9 

400kV  Gooty‐Neelmangala:SPS‐9  Tripping  of  one  of  the  400kV  Gooty‐Nelamangala  SC  line  or  400kV  Gooty‐ 

Western Region  500MW Gen Back down JPL ‐ 350MW KSK ‐  150MW Southern Region  

 Western Region  800 MW Gen Back down More  generators  such  as Lanco  Amarkantak,  KWPCL, BALCO,  JPL  Ext,  NSPCL  etc. 

Rationale: One argument cited by  generators  towards inadequate  relief  is  the  low antecedent  generation  on these units. As this would be a highly  probable  scenario,  SPS wiring may be done  for more 

Page 9 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

Somanahalli  SC  line  and  Flow  on  other line > 850 MW  

500MW Load Shedding Tamilnadu‐            146MW Kerala ‐                   125MW Karnataka‐             104MW Andhra Pradesh    125MW 

must  be  covered  in W3  area so  that  800  MW  relief  is available under all conditions.. Southern Region  No change 

quantum  so  that  800  MW relief is always available.  

10  Talcher‐Kolar SPS‐10 In case of single pole or bipole outage or blocking of Talcher‐Kolar HVDC sensed at Talcher HVDC terminal,  

Trip signal be extended to nearby generators  such  as  Sterlite, GMR, JITPL  and  Talcher  Stage‐I  for  gen reduction of 600 MW  so  that  the injection  into  NEW  grid  is restricted to 450 MW. Eastern Region:‐ Sterlite  = 350MW GMR      = 250MW JITPL      = 0  This would be in addition to SPS 1000 already in operation at Talcher‐II. 

 Eastern region:  JITPL  unit  also  needs  to  be connected.  Further  relief from GMR was  not  available on  25th  March  2014  when one  pole  of  Talcher‐Kolar HVDC  bipole  tripped;  so  the unit  selection  logic  at  GMR needs to checked.   600  MW  relief  must  come from  Sterlite, GMR  and  JITPL under all conditions.     

Rationale: Even after Southern region  is  synchronized,  the system  is  still not planned  for single  pole  of  Talcher‐Kolar HVDC bipole going out. 

Page 10 of 10

S. no 

Triggering criteria for SPS(implemented) SPS  action implemented Proposed revision in SPS Remarks

11  Kudankulam : SPS‐11 SPS  of  Kudankulam  Unit  and  SPS  of Talcher‐Kolar  Pole  trip  at  Kolar  end  are having  the  same  group  of  loads  for shedding  and  these  needs  to  be segregated  at  the  earliest  by  identifying separate loads for Kudankulam SPS.  

    

 

Note: SPS-1, 2 and SPS-5 have operated frequently during the last three months while the others have either not operated or operated infrequently. Notwithstanding the above revisions suggested, the following are also important. o Improving reliability of SPS through redundant measurements, logic, communication path and end terminals. o Use of metering core of CTs and PTs for analog measurements used in the SPS logic, particularly where the same is based on

steady state flows crossing a particular value. o Need to cover more generators in the NEW grid so that adequate relief is available as in many instances, the antecedent

generation in many of the generators selected is already very low. o Wiring of each SPS operation to the local substation Event Logger. o Triggering of each SPS action and the receipt of signal at each point to be recorded in SLDC/RLDC/NLDC SCADA o Prompt submission of data to RLDCs regarding SPS action in the prescribed format. o Each instance of inadequate relief through SPS to be thoroughly analysed and remedial actions taken so as to have increased

confidence on the SPS reliability.

Annexure – 7.3Table-I

Revisions in System Protection Scheme(SPS)- NEW grid-SR synchronisation

SPS Name Triggering Criteria Load shedding bySR/Backing downin WR in MW

Contribution bygenerators

SPS-1: SholapurRaichur Power flow

i) When flow on 765kVSholapur-Raichur S/C linecrosses 1000 MW andremains above this valuefor 2.5 sec in the directionSholapur to Raichur.ii) Power flow crosses 1500MW in direction Sholapur toRaichur (instantaneous)

500/800 JPL-150MW,JPL extn-150MW,KSK-100MW,LANCO-100MW,DBPOWER-100MWKWPCL-100MWBALCO-50MWNSPCL-50MW

SPS-2: Rate ofchange of powerflow in Sholapur-Raichur>400MW/sec

Temporarily blocked NA NA

SPS-3: Loss ofSholapur- Raichurline carrying 800MW towards SR

Loss of 800MW import bySR due to tripping of 765kVSholapur-Raichur line

500/Nil Load Generationbalance in NEWgrid to beachieved bygovernor actionof generators

SPS-4: 400kV Raipur-Wardha Power flow

) Antecedent flow on eitherof the 400kV Raipur-Wardha line crossing 850MW and remaining abovethis value for 2.5 sec.ORii) tripping of any circuitwhen the flow is greaterthan 700 MW(instantaneous)

800/800 Same as for SPS-1

SPS-5: 400kVWardha- Parli PowerFlow

i)Flow crossing 850 MW oneach circuit with a timedelay of 2.5 sec

ORii) tripping of S/C carrying750 MW (instantaneous)sensed at Wardha end.

800/800+generation pickup at Koynaimmediately.

Tiroda-200MW,Mauda-100MW,Koradi-70MW,Khaperkhada-150MW,Chandrapur-250MWIndiabulls-30MW

SPS Name Triggering Criteria Load shedding bySR/Backing downin WR in MW

Contribution bygenerators

SPS-6: 400kV Parli -Sholapur PowerFlow

i) Flow crossing 850 MW oneach circuit with a timedelay of 2.5 sec ORii) tripping of any circuitwhen flow is > than 600MW sensed atSholapur.(instantaneous)

800/800 Same as for SPS-1

SPS-7: 765kVRaichur- Sholapurline currentexceeding 800Amp(1000MW) in eitherdirection

Current exceeding 800Amp(1000MW )in Sholapur toRaichur direction. Reversedirection ie., SR to NEW gridmay be blocked.

Tripping of765kV Sholapur-Raichur line with10 sec delay.

SPS-8: 400kV HiriyurNeelmangala PowerFlow

Tripping of one line andother line loading going upto 850 MW(instantaneous)

500/800 Same as SPS-1

SPS-9: GootyNeelmangala/GootySomanahalli PowerFlow

Tripping of one of the 400kVGooty‐Nelamangala SC line or400kV Gooty‐SomanahalliSC line and Flow on otherline > 850 MW(instantaneous)

500/800 Same as SPS-1

SPS-10: Talcher-Kolar SPS

In case of single pole orbipole outage or blocking ofTalcher-kolar HVDC sensedat Talcher HVDC terminal.

LS in SR-600MWGen.B/d by ER-600MW

Sterlite,GMR,JITPL

Table-I

SPS Name  Triggering Criteria  Backing down in WR in MW 

Contribution by generators 

SPS‐1: Sholapur Raichur Power flow 

i) When flow on 765kV Sholapur‐Raichur S/C line crosses  800 MW and remains above  this value for 2.5 sec in the direction Sholapur to Raichur. ii) Power flow crosses 1000 MW in direction Sholapur to Raichur (instantaneous) 

500   JPL‐350MW, KSK‐150MW.  

SPS‐2: Rate of change of power flow in Sholapur‐ Raichur>400MW/sec 

Temporarily blocked  NA  NA 

SPS‐3: Loss of Sholapur‐ Raichur line carrying 800 MW towards SR 

Loss of 800MW import by SR due to tripping of 765kV Sholapur‐Raichur line  

Nil  Load Generation balance in NEW grid to be achieved by  governor action of generators 

SPS‐4: 400kV Raipur‐ Wardha Power flow 

) Antecedent flow on either of the 400kV Raipur‐Wardha line crossing 850 MW and remaining above this value for 2.5 sec. OR ii) tripping of any circuit when the flow is greater than  700 MW (instantaneous)  

800  JPL‐600MW, KSK‐200MW.  

SPS‐5: 400kV Wardha‐ Parli Power Flow 

i)Flow crossing 850 MW on each circuit with a time delay of 2.5 sec           OR ii) tripping of S/C carrying 750 MW (instantaneous) sensed at Wardha end.  

800+  generation pick up at Koyna immediately. 

APL Tiroda‐600MW, Mauda‐200MW.    

SPS Name  Triggering Criteria  Load shedding by SR/Backing down in WR in MW 

Contribution by generators 

SPS‐6: 400kV Parli ‐Sholapur Power Flow 

i) Flow crossing  800 MW on each circuit with a time delay of 2.5 sec OR ii) tripping of any circuit when flow is > than 600 MW sensed at Sholapur.(instantaneous) 

800  JPL‐600MW, KSK‐200MW.  

 SPS‐7: 765kV Raichur‐ Sholapur line current exceeding 800Amp (1000MW) in either direction 

Current exceeding 800Amp (1000MW )in Sholapur to Raichur  direction. Reverse direction ie., SR to NEW grid  may be blocked.  

Tripping of 765kV Sholapur‐Raichur line with 10 sec delay.  

NA 

SPS‐8: 400kV Hiriyur Neelmangala Power Flow 

Tripping of one line and other line loading going up to 850 MW (instantaneous) 

500  JPL‐350MW, KSK‐150MW.  

SPS‐9: Gooty Neelmangala/Gooty Somanahalli  Power Flow 

Tripping of one of the 400kV Gooty‐ Nelamangala SC line or 400kV Gooty‐Somanahalli SC line and Flow on other line > 850 MW (instantaneous)  

500  JPL‐350MW, KSK‐150MW.  

SPS‐10: Talcher‐Kolar SPS 

In case of single pole or bipole outage or blocking of Talcher‐kolar HVDC  sensed at Talcher HVDC terminal.  

LS in SR‐600MW Gen.B/d by ER‐600MW 

Sterlite,GMR,JITPL  

6/13/2014

1

Sequence of eventsCondition prior to the fault:

1. 400kV Bachau - Vadavi 2 line was out for maintenance work.2 220kV Bachau – Halvad DC lines were also out

Annex-8

2. 220kV Bachau Halvad DC lines were also out 3. Initial Conditions: Unit 10 to 50 were operating at 831, 812, 832,795 and

819 MW. 4. The lines were exporting about 3750 MW of power :

Mundra-Bhachau #1=561MW, Bhachau Line#2=559MW,Mundra-Chorania#1=754MW, Mundra-Chorania#2=835MW, Mundra-Jetpur#1=572MW and Mundra-Jetpur#2=574MW.

…Message Box ( Arial, Font size 18 Bold)

The Network with Line loads are as given the diagram:

Line loading before incident

320

(1 & 2)

Limbdi /

…Message Box ( Arial, Font size 18 Bold)Mundra black out on 12-03-4014

1) 220kV Load

2) APL: Adani Power Limited

6/13/2014

2

Chorania Sub Station SLD

R

Mundra-Chorania Line -1 Mundra-Chorania Line -2

LA of NGR failed

Bus-I

Bus-II

R

RR

R F1

LA of NGR failed

…Message Box ( Arial, Font size 18 Bold)Mundra black out on 12-03-4014

Kosamba Line -1 Kosamba Line -2

Line Reactor Bushing Failed

Sequence of Events• At 19:10:25:732 hrs: The disturbance started with Reactor Bushing failure

on 400kV Chorania-Kosamba Line#2 and resulted in fire in the station. At the same time, 400kV Mundra-Chorania Line#1 tripped on Direct Trip Receive from remote end due to Line Reactor REF operation (ChoraniaLi #1 NGR ‘LA’ h d f il d t t d)Line#1 NGR ‘LA’ had failed at remote end).

• The change in power flow resulted in line exports:Mundra-Bhachau Line 1 = 633MW, Mundra Bhachau-Line 2= 694MW, Mundra-Chorania Line 2= 980MW, Mundra- Jetpur Line 1=704MW and Mundra- Jetpur Line 2 =707MW

• The System remained stable for about 10 to 11 Minutes till second 440kV Mundra-Chorania Line-1 tripped due to suspected mal-operation of LBBU Relay of Chorania – Kosamba Line#2 (already tripped line).

…Message Box ( Arial, Font size 18 Bold)

• At 19:21:39:798 hrs: 400kV Mundra Chorania Line#2 tripped by Direct trip receive on account of B.F. L/O operation (LBBU mal-operation).

• Since both 400kV Mundra-Chorania Lines were lost and CGPL export was more than 3200 MW, Special Protection Scheme (SPS) operated making Unit#40 to go into runback mode.

6/13/2014

3

Line loading after first incident

…Message Box ( Arial, Font size 18 Bold)Mundra black out on 12-03-4014

Chorania Sub Station - second fault

R

Mundra-Limbdi Line -1 Mundra-Limbdi Line -2

Though line is off and isolated LBB

Bus-I

Bus-II

R

RR

RR

and isolated, LBB has operated of 

Kosmba line which has isolated complete bus, 

including Lim line‐2 breaker

R

RR

Bus Coupler

R

…Message Box ( Arial, Font size 18 Bold)Mundra black out on 12-03-4014

KosambaLine -1

KosambaLine -2

Asoj Line -2 ICT-2ICT-1

Amreli Vadavi-1Vadavi-2

6/13/2014

4

Line availability after second incident

…Message Box ( Arial, Font size 18 Bold)Mundra black out on 12-03-4014

Sequence of Events• After tripping of Chorania#2 line & loss of load at Chorania Station, even

though Unit#40 was doing run back; due to lack of Transmission corridors, CGPL units started swinging with respect to the Grid.

…Message Box ( Arial, Font size 18 Bold)

6/13/2014

5

Sequence of Events• Due to the Power Swing, Voltage at Mundra had gone up from 400kV to

600kV resulting in

At 19:21:41:291 hrs: Mundra-Bhachau Line 1 tripped on over voltage protectionpp g p

At 19:21:41:323 hrs: Mundra-Bhachau Line 2 tripped on Z1 distance protection, 69 km from Mundra probably due to flashover of insulator due to O/V.

At 19:21:41:325 hrs: Mundra-Jetpur Line 2 tripped on over voltage protection

At 19:21:41:337 hrs: Mundra-Jetpur Line 1 tripped on over voltage protection

…Message Box ( Arial, Font size 18 Bold)

Effect of heavy power swing

…Message Box ( Arial, Font size 18 Bold)Mundra black out on 12-03-4014

6/13/2014

6

Sequence of Events• Since all lines emanating from Mundra had tripped, the units got unloaded

and came to house load due to high frequency caused by load throw off

At 19:21:42:627 hrs: Unit#40 tripped on SPS Protection as both 400kV BachauppLines had tripped on O/V.

At 19:21:42:681 hrs: Unit 50 hand tripped as unit got unloaded

At 19:23:55:001 hrs: Unit 20 hand tripped as unit got unloaded

At 19:27:27:324 hrs: Unit 30 hand tripped as unit got unloaded

…Message Box ( Arial, Font size 18 Bold)

At 19:28:22:167 hrs: Unit 10 tripped, unit tripped on HP exhaust hood temp Hi Hi > 460 C resulting in total shut down of CGPL station.

HCL

Text Box

Annex-9.3

OverVoltage (%)

Time Delay(Secs)

OverVoltage (%)

Time Delay(Secs)

OverVoltage (%)

Time Delay(Secs)

OverVoltage (%)

Time Delay(Secs)

1 765 Bina - Gwalior -I 108 7 150 0.1 108 7 150 0.1

2 765 Bina - Gwalior -II 109 8 150 0.1 109 8 150 0.1

3 765 Satna-Gwalior 1 109 5 150 0.1 109 5 150 0.1

4 765 Satna-Gwalior 2 Not Charged yet Not Charged yet

5 765 Seoni - Bilaspur # 1 109 5 150 0.1 above 98% 109 5

6 765 Seoni - Bilaspur # 2 108 7 150 0.1 above 98% 108 7 150 0.1 above 98%7 765 Seoni - Bina 108 7 150 0.1 above 98% 108 7 150 0.18 765 Seoni - Wardha # 1 109 5 150 0.1 above 98% 109 5 150 0.1 above 98%

9 765 Seoni - Wardha # 2 107 6 150 0.1 above 98% 107 6 150 0.1 above 98%

10 765 Tamnar PS - Kotra (Raigarh) PS # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

11 765 Tamnar PS - Kotra (Raigarh) PS # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

12 400 Akola - Aurangabad - I (PGCIL) 110 5 150 0.1 110 5 150 0.1

13 400 Akola - Aurangabad - II (PGCIL) 110 6 150 0.1 110 5 150 0.1

14 400 Akola - Aurangabad (MSETCL) # I 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

15 400 Akola - Aurangabad (PGCIL) # II 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

16 400 Akola - Bhusawal 110 7.5 150 0.1 110 5 150 0.1

17 400 Akola - Wardha-I (PGCIL) 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

18 400 Akola - Wardha-II (PGCIL) 110 6 150 0.1 above 98% 110 7.5 150 0.1 above 98%

19 400 Amreli - Jetpur -1 110 5 130 0.15 110 4 135 Instantaneous

20 400 Amreli - Jetpur -2 110 5 130 0.15 110 3 160 0.15

21 400 Asoj - Chorania -1 110 3 or 5 125 0.15 110 3 140 0.15

22 400 Asoj - Chorania -2 110 5 140 Instanteneous 110 5 140 0.1

23 400 Asoj - Indore -1 110 4 140 or 150 Instanteneous 110 4 130 or 150 Instantaneous

24 400 Asoj - Indore -2 110 6 130 or 150 0.1 110 6 130 or 150 Instantaneous

25 400 Asoj - Kosamba 110 4 140 Instanteneous 110 4 150 Instantaneous

26 400 Aurangabad (PG) - Aurangabad (MSETCL) # II 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

27 400 Bableshwar - Padghe I 110 3 150 Instantaneous 110 7 150 0.10

28 400 Bableshwar - Aurangabad 110 3 150 Instantaneous 110 4 150 0.10

29 400 Bableshwar - Bhusawal 110 4 150 Instantaneous 110 5 150 0.1

30 400 Bableshwar - Dhule I 114 3 150 Instantaneous 110 3 150 0.131 400 Bableshwar - Dhule II 114 6 150 Instantaneous 110 6 150 0.132 400 Bableshwar - Padghe II 110 6 150 Instantaneous 110 5 150 0.10

33 400 Bhachau - Vadavi (Ranchodpura) # 1 110 4 150 0.1 110 4 150 0.1

34 400 Bhachau - Vadavi (Ranchodpura) # 2 110 5 150 0.1 110 5 or 6 150 0.1

35 400 Bhadravati - Chandrapur # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

36 400 Bhadravati - Chandrapur # 2 110 6 150 0.1 above 98% 110 6 150 0.1 above 98%

37 400 Bhadravati - Chandrapur # 3 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

38 400 Bhadravati - Chandrapur # 4 110 8 150 0.1 above 98% 110 8 150 0.1 above 98%

39 400 Bhilai - Bhadravati 110 5 150 0.1 110 5 150 0.1 above 98%

40 400 Bhilai - Bhatapara 110 5 150 0.1 110 5 150 0.1 above 98%

41 400 Bhilai - Raipur I 110 5 150 0.1 110 5 150 0.1 above 98%

42 400 Bhilai - Seoni 110 5 150 0.1 110 5 150 0.1 above 98%

43 400 Bhilai (PGCIL) - Koradi 110 5 150 0.1 110 5 150 Instanteneous above 98%

44 400 Bhopal - Bina 1 107 4 125 Instantaneous 107 4 120 Instantaneous

45 400 Bhopal - Bina 2 110 6 125 Instantaneous 110 6 120 Instantaneous

46 400 Bhopal - Itarsi 1 110 6 125 Instantaneous 110 6 150 0.10

Annexure - 10.2

Line (End -I & End II)S. No. kV Pick up toDrop out

Ratio

Stage I Stage II Pick up toDrop out

Ratio

End IIStage II

End IStage I

47 400 Bhopal - Itarsi 2 108 4 125 Instantaneous 110 4 150 0.10

48 400 Bhusawal - Aurangabad 110 5 150 0.10 110 6 150 0.10

49 400 Bhusawal - Bhusawal(D'nagar)-I 110 4 150 0.1 110 4 150 Instantaneous

50 400 Bhusawal - Bhusawal(D'nagar)-II 110 6 150 0.1 110 6 150 Instantaneous

51 400 Bhusawal - Deepnagar - I 110 4 150 Instantaneous 110 4 150 Instantaneous

52 400 Bhusawal - Deepnagar - II 110 6 150 Instantaneous 110 6 150 Instantaneous

53 400 Bhusawal - Koradi 110 5 150 0.10 110 5 150 Instanteneous

54 400 Bina - Bina (PG) 3 MPPTCL NA WR II NA

55 400 Bina - Bina (PG) 4 MPPTCL NA WR II NA

56 400 Bina - Shujalpur#1 110 5 150 0.1 110 5 150 0.1

57 400 Bina - Shujalpur#2 110 4 150 0.1 110 4 150 0.1

58 400 Bina (PGCIL) - Bina (MPPTCL) #1 110 6 150 0.1 110 4 150 Instantaneous

59 400 Bina (PGCIL) - Bina (MPPTCL) #2 110 7 150 0.1 110 6 150 Instantaneous

60 400 Birsinghpur - Balco (Vandana) 110 6 150 0.10 110 3 140 161 400 Boisar - Padge 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

62 400 Chakan - Lonikand 110 5 150 0.05 110 5 150 0.05

63 400 Chakan - Talegaon (Pune - PGCIL) 110 5 150 0.05 110 5 150 0.10 above 98%

64 400 Chandrapur - II - GCR Chandrapur-I 110 5 150 0.10 110 5 150 0.1

65 400 Chandrapur - II - GCR Chandrapur-II 110 6 150 0.10 110 6 150 0.1

66 400 Chandrapur - II - Parli-I 110 5 150 0.10 110 3 150 0.1

67 400 Chandrapur - II - Parli-II 110 6 150 0.10 110 6 150 0.1

68 400 Chandrapur - II - Warora-I 110 6 150 0.10 110 5 150 0.1

69 400 Chandrapur - II - Warora-II 110 7 150 0.10 110 5 150 0.1

70 400 Chandrapur - Khaparkheda 110 5 150 0.10 110 5 150 Instanteneous

71 400 Chandrapur - Parli - III 110 7 150 0.10 110 8 150 0.1

72 400 Chorania - Amreli 110 5 140 0.15 110 5 125 or 130 0.15

73 400 Chorania - Vadavi (Ranchodpura) -1 110 3 or 4 130 or 150 Instanteneous 110 4 150 0.15

74 400 Chorania - Vadavi (Ranchodpura) -2 110 5 or 6 150 or 130 Instanteneous 110 6 or 4 150 0.15

76 400 Chorania-Hadala 105 4 135 0.15 110 4 140 0.15

79 400 Dabhol - Nagothane I 110 6 150 Instantaneous 110 6 150 0.10

80 400 Dabhol - Nagothane II 110 4 150 Instantaneous 110 5 150 0.10

81 400 Dabhol - NewKoyna I 110 4 150 Instantaneous 110 4 150 Instantaneous

82 400 Dabhol - NewKoyna II 112 6 150 Instantaneous 112 6 150 Instantaneous

83 400 Damoh - Bhopal # 1 110 4 150 0.1 110 4 150 0.1

84 400 Damoh - Bhopal # 2 110 4 or 5 150 0.1 110 4 150 0.1

85 400 Damoh - Birsinghpur # 1 110 4 150 0.1 110 4 150 0.1

86 400 Damoh - Birsinghpur # 2 110 5 150 0.1 110 5 150 0.1

87 400 DB Power Ltd. - Raigarh 110 5 140 0.1 110 5 150 0.1 above 98%

88 400 Deepnagar - Aurangabad - I 110 4 150 Instantaneous 110 4 150 Instantaneous

89 400 Deepnagar - Aurangabad - II 110 6 150 Instantaneous 110 6 150 Instantaneous

90 400 Dehgam - Nagda # 1 110 5 150 0.1 110 5 150 0.1

91 400 Dehgam - Nagda # 2 110 6 150 0.1 110 6 150 0.1

92 400 Dehgam - Pirana#1 110 4 150 0.1 110 4 150 0.1

93 400 Dehgam - Pirana#2 110 5 150 0.1 110 5 150 0.1

94 400 Dehgam - Vadavi (Ranchodpura)-1 110 5 130 0.10 110 4 150 0.15

95 400 Dehgam - Vadavi (Ranchodpura)-2 110 4 130 0.10 110 4 150 0.15

96 400 Dehgam- Wanakbori 110 4 150 0.1 111 4 150 0.10

97 400 Dhule - SSNL I 110 7 150 0.10 110 3 130 0.05

98 400 Dhule - SSNL II 110 6 150 0.10 110 6 130 0.05

99 400 Hadala - Mundra (APL) 110 6 130 0.05 110 5 150 0.1 95%

100 400 Hadala - Vadinar-1 110 5 or 4 140 0.15 110 5 140 0.1

101 400 Hadala - Vadinar-2 110 3 140 0.15 110 5 140 0.1

102 400 Hadala - Varsana 110 3 or 2 130 or 140 0.15 110 5 150 0.1

103 400 Hadala-Amreli 110 3 140 0.15 110 5 130 0.1

104 400 Hadala-APL 110 6 140 0.15 110 5 150 0.1

105 400 Indore - Nagda 110 4 125 Instantaneous 110 5 125 Instantaneous

106 400 Itarsi - Indore ckt I 110 5 150 0.1 110 5 130 or 150 0.1

107 400 Itarsi - Indore ckt II 110 4 150 0.1 110 4 130 or 150 0.1

108 400 Itarsi - Khandwa # I 110 4 150 0.1 110 4 150 0.1

109 400 Itarsi - Khandwa # II 110 5 150 0.1 110 5 150 0.1

110 400 Jabalpur - Itarsi # I 110 4 150 0.1 110 4 150 0.1

111 400 Jabalpur - Itarsi # II 110 6 150 0.1 110 6 150 0.1

112 400 Jabalpur - Itarsi # III 110 5 150 0.1 110 5 150 0.1

113 400 Jabalpur - Itarsi # IV 110 7 150 0.1 110 7 150 0.1

114 400 Jejuri - Koyna Stage IV 110 5 150 0.05 110 5 150 0.05

115 400 Kalwa - Kharghar 110 5 150 0.1 110 5 150 0.1

116 400 Karad - Kolhapur II 110 6 150 0.01 110 6 150 Instantaneous

117 400 Karad - Kolhapur-I 110 4 150 Instantaneous 110 4 150 0.01

118 400 Karad - Lonikand 110 7 150 Instantaneous 110 5 150 0.05

119 400 Karad - New Koyna - I 110 6 150 Instantaneous 110 3 150 Instantaneous

120 400 Karad - New Koyna - II 110 8 150 Instantaneous 110 6 150 Instantaneous

121 400 Karad - Talandge # 1 110 4 150 0% 110 4 150 0.01

122 400 Karad - Talandge # 2 110 6 150 0% 110 6 150 0.01

123 400 Kasor - Chorania 110 3 120 0.05 110 4 140 0.15

124 400 Kasor -Chorania 110 4 130 0.15 110 4 140 0.15

125 400 Katani - Damoh 108 5 120 Instantaneous 110 5 150 0.10

126 400 Khandwa - Dhule # 1 110 5 150 0.1 110 5 or 6 150 0.1

127 400 Khandwa - Dhule # 2 110 6 150 0.1 110 6 150 0.1

128 400 Khandwa - Rajgarh # 1 110 5 150 0.1 110 5 150 0.1

129 400 Khandwa - Rajgarh # 2 110 4 150 0.1 110 4 150 0.1

130 400 Khaparkheda - Koradi-1 110 8 150 Instanteneous 110 5 150 Instanteneous

131 400 Khaparkheda - Koradi-2 110 7 150 Instanteneous 110 5 150 Instanteneous

132 400 Khedamara - Raita 110 4 130 Instanteneous 110 4 130 Instanteneous

133 400 Khedamara - Seoni 110 4 140 Instanteneous 110 5 150 0.1

134 400 Kolhapur - Mapusa # 1 112 5 150 0.1 110 5 150 0.1 above 98%

135 400 Kolhapur - Mapusa # 2 112 7 150 0.1 above 98% 110 7 150 0.1 above 98%136 400 Koradi - Koradi (New) 110 5 150 Instanteneous 110 5 150 0.15137 400 Koradi - Satpura 110 5 150 Instanteneous above 98% 110 5.5 150 0.1138 400 Korba - BALCO 110 3 140 0.1 above 98% 110 3 140 or 150 1 or 0.1 above 98%139 400 Korba - Bhatapara 110 5 or 3 150 or 140 0.1 110 5 150 0.1 above 98%140 400 Korba - Bhilai I 109 5 140 0.1 above 98% 110 5 150 0.1 above 98%141 400 Korba - Bhilai II 109 5 140 0.1 110 7 150 0.1142 400 Korba - Korba (W) 110 5 disable or 150 disable or 0.1 above 98% 110 5 150 0.1

144 400 Korba - Pathadi (Lanco) 110 5 140 or 150 0.1 above 98% 110 5 140 or 150 0.1 above 98%

145 400 Korba - Raipur # 3 110 3 140 0.1 above 98% 110 5 150 0.1 above 98%

146 400 Korba - Raipur # 4 110 3.5 140 0.1 above 98% 110 7 150 0.1 above 98%147 400 Kosamba - Chorania-1 110 4 140 0.15 110 4 150 0.15148 400 Kosamba - Chorania-2 110 4 140 0.15 110 6 140 0.15149 400 Kosamba - Ukai 1 110 4 140 0.15 110 3 120 Inst.150 400 Kosamba - Ukai 2 110 4 140 0.15151 400 Kosamba - Ukai 3 110 4 140 0.15152 400 KSK- DB Power Ltd. 110 5 140 0.1 110 5 140 0.1153 400 Lamboti - Parli 110 5 150 0.05 112 5 150 0.1154 400 Lonikand - Jejuri 110 5 150 0.05 110 5 150 0.05

155 400 Lonikand - Parli -I 110 4 150 0.05 112 8 150 0.1156 400 Lonikand - Parli -II 110 6 150 0.05 110 6 150 0.1157 400 Mundra - Bhachau (PGCIL) - I 110 4 130 0.1 110 4 150 0.10158 400 Mundra - Bhachau (PGCIL) - II 110 5 130 0.1 110 5 150 0.10

159 400 Mundra - Jetpur (PGCIL) - I 110 4 130 0.1 110 5 150 0.10160 400 Mundra - Jetpur (PGCIL) - II 110 5 130 0.1 110 6 150 0.10161 400 Mundra - Limbdi (Chorania - PGCIL) - I 110 4 130 0.1 110 4 150 0.10162 400 Mundra - Limbdi (Chorania -PGCIL) - II 110 5 130 0.1 110 5 150 0.10163 400 Mundra (APL) - Versana 110 5 150 0.1 95% 112 5 150 0.15164 400 Nagda - Rajgarh 1 110 5 138 Instantaneous 110 5 150 0.1165 400 Nagda - Rajgarh 2 110 5 138 Instantaneous 110 6 150 0.1166 400 New Koyna - Stage IV ckt -I 110 5 150 Instantaneous 110 5 150 0.05167 400 New Koyna - Stage IV ckt -II 110 6 150 Instantaneous 110 6 150 0.05

168 400 New Koyna Stage IV - Lonikand 110 3 150 0.05 110 5 150 0.05169 400 Padghe - Kalwa 1 110 5 150 0.1 110 4 150 0.1170 400 Padghe - Kalwa 2 110 6 150 0.1 110 6 150 0.1171 400 Padghe - Kharghar 110 5 150 0.1 110 5 150 0.1172 400 Padghe - Nagothane 1 110 5 150 0.1 110 5 150 0.1173 400 Padghe - Nagothane 2 110 6 150 0.1 110 6 150 0.1174 400 Parli - Bhadrawati # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%175 400 Parli - Bhadrawati # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

176 400 Parli (PGCIL) - Parli (Girwali - MSETCL) # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

177 400 Parli (PGCIL) - Parli (Girwali - MSETCL) # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

178 400 Pathadi (Lanco) - Sipat 110 5 140 or 150 0.1 above 98% 110 5 140 or 150 0.02 or 0.1 above 98%

179 400 Pune - Parli # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

180 400 Pune - Parli # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

181 400 Raigarh - Kotra PS # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

182 400 Raigarh - Kotra PS # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

183 400 Raipur - Bhadravati # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

184 400 Raipur - Bhadravati # 2 110 6 150 0.1 above 98% 110 6 150 0.1 above 98%

185 400 Raipur - Bhadravati # 3 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

186 400 Raipur - Durg PS # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

187 400 Raipur - Durg PS # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%

188 400 Raipur - JPL - I 110 5 140 0.1 110 5 140 0.1

189 400 Raipur - JPL - II 110 7 140 0.1 110 5 140 0.1

190 400 Raipur - KSK 110 5 150 0.1 above 98% 112 5 150 0.1191 400 Raipur - Raigarh # 4 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%192 400 Raipur - Raigarh # 1 110 5 150 0.1 above 98% 112 5 150 0.1 above 98%193 400 Raipur - Sipat # I 110 5 150 0.1 above 98% 110 4 140 0.02194 400 Raipur - Sipat # II 110 6 150 0.1 above 98% 110 4 140 0.02195 400 Raipur - Sipat # III 110 7 150 0.1 110 5 140 0.02 above 98%196 400 Raipur - Wardha # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%197 400 Raipur - Wardha # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%198 400 Ranchi - Sipat # 1 110 4 150 0.1 115 or 110 3 or 4 140 or 150 0.02 or 0.1 above 98%199 400 Ranchi - Sipat # 2 110 5 150 0.1 115 or 110 4 or 5 140 or 150 0.02 or 0.1 above 98%200 400 Sami - Dehgam -1 110 4 150 0.1 0.99 110 4 150 0.10201 400 Sami - Dehgam -2 110 5 150 0.1 0.99 110 5 150 0.10202 400 Satna - Bina (PG) - I 110 4 150 0.1 110 4 150 0.1203 400 Satna - Bina (PG) - II 110 5 150 0.1 110 5 150 0.1204 400 Satna - Bina (PG) - III 110 7 150 0.1 110 7 150 0.1205 400 Satna - Bina (PG) - IV 110 6 150 0.1 110 6 150 0.1206 400 Satpura - Itarsi 110 5 150 0.1 110 5 150 0.1207 400 Satpura - Seoni 110 - 150 0.1 110 5 150 0.1 above 98%208 400 Seoni - Khandwa # 1 with FSC (40%) 110 5 150 0.1 above 98% 110 5 150 0.10209 400 Seoni - Khandwa # 2 with FSC (40%) 110 7 150 0.1 above 98% 110 4 150 0.10210 400 Shujalpur - Nagda #1 110 4 150 0.1 110 4 150 0.1

211 400 Shujalpur - Nagda #2 110 5 150 0.1 110 5 150 0.1212 400 Soja - Dahegam 110 5 120 Instantaneous 110 or 112 4 or 3 150 0.1214 400 Soja - Kansari 108 4 120 0.05 110 4 or 2 150 or 120 0.15215 400 Soja - Wanakbori 110 3 120 Instantaneous 110 5 120 Instantaneous

217 400 Solapur (Lamboti) - Solapur (PGCIL) 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%

218 400 Solapur (PGCIL) - Karad (MSETCL) 110 5 150 0.1 above 98% 110 5 150 Instateneous above 98%219 400 Solapur (PGCIL) - Kolhapur # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%220 400 Solapur (PGCIL) - Kolhapur # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%221 400 Solapur -Parli # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%222 400 Solapur -Parli # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%223 400 SSP - Rajgarh # 1 110 5 130 0.05 110 5 150 0.10224 400 SSP - Rajgarh # 2 110 7 130 0.05 110 6 150 0.10225 400 Talegaon (Pune - PGCIL) - Padghe (MSETCL) 110 5 150 0.10 above 98% 110 4 150 0.1226 400 Talegaon (Pune -PGCIL) - Kalwa (MSETCL) 110 5 150 0.10 above 98% 110 5 150 0.1227 400 Tarapur - Boisar # 1 110 5 150 0.1 110 5 150 0.1 above 98%228 400 Tarapur - Boisar # 2 110 7 150 0.1 110 7 150 0.1 above 98%229 400 Tarapur - Padge # 1 110 5 150 0.1 110 5 150 0.1 above 98%230 400 Tarapur - Padge # 2 110 7 150 0.1 110 6 150 0.1 above 98%231 400 Tirora (APL) - Warora -1 110 7 140 0.15 0.95 110 5 150 Instanteneous232 400 Tirora (APL) - Warora -2 110 5 140 0.15 0.95 110 7 150 Instanteneous

233 400 Vadavi-Dahegam-1 110 4 140 0.15 110 4 150 0.1234 400 Vadavi-Dahegam-2 110 4 140 0.15 110 4 150 0.1235 400 Vadavi-Kansari-1 110 4 150 0.1 110 5 150 0.1236 400 Vadavi-Kansari-2 110 4 150 0.1 110 5 150 0.1237 400 Vandana-Birsinghpur 110 5 150 0.1 above 98% 110 7 150 0.1 above 98%238 400 Vapi - Boisar 110 5 150 0.1 110 5 150 0.1 above 98%239 400 Vapi - Navsari#1 110 4 150 0.1 110 4 150 0.1240 400 Vapi - Navsari#2 110 5 150 0.1 110 5 150 0.1241 400 Vindhyachal - Jabalpur - I 110 6 140 0.1 110 7 150 0.10242 400 Vindhyachal - Jabalpur - II 110 7 140 0.1 110 6 150 0.10243 400 Vindhyachal - Jabalpur - IV 110 6 140 0.1 110 4 150 0.10244 400 Vindhyachal - Korba # II 110 4 or 5 140 or 150 0.1 above 98% 110 4 or 5 140 or 150 0.1 above 98%245 400 Vindhyachal - Satna - I 110 5 140 0.1 110 5 150 0.10246 400 Vindhyachal - Satna - II 110 4 140 0.1 110 6 150 0.10247 400 Vindhyachal - Satna - III 110 3 140 0.1 110 4 150 0.10248 400 Vindhyachal - Satna - IV 110 3 140 0.1 110 7 150 0.10249 400 Wardha-Parli # 1 110 5 150 0.1 above 98% 110 5 150 0.1 above 98%250 400 Wardha-Parli # 2 110 7 150 0.1 above 98% 110 7 150 0.1 above 98%251 400 Warora - Wardha (PGCIL) Ckt-I 110 5 150 Instanteneous 110.00 5 150 0.1252 400 Warora - Wardha (PGCIL) Ckt-II 110 7 150 Instanteneous 110.00 7 150 0.1253 Akola - Nandgaon Peth (Indiabulls) 110 7.5 150 0.1 110 5 150 0.1254 Indore (PG) - Indore (MPPTCL) # 1 110 5 150 0.1 110 5 150 0.1255 Indore (PG) - Indore (MPPTCL) # 2 110 6 150 0.1 110 6 150 0.1256 Jabalpur - Jabalpur (Pooling) # 1 110 5 150 0.1 110 5 150 0.1257 Jabalpur - Jabalpur (Pooling) # 2 110 6 150 0.1 110 6 150 0.1258 JPL Tamnar -Tamnar (PG)-1 110 5 140 1 110 5 140 1259 JPL Tamnar -Tamnar (PG)-2 110 5 140 1 110 5 140 1260 JPL Tamnar -Tamnar (PG)-3 110 5 140 1 110 5 140 1261 JPL Tamnar -Tamnar (PG)-4 110 5 140 1 110 5 140 1262 JPL-JPL Tamnar 1 110 5 140 0.2 110 5 140 0.2263 Mauda - Wardha (PGCIL) - II 110 5 140 0.1 0.98 110 7 150 0.1

OverVoltage (%)

Time Delay(Secs)

OverVoltage (%)

Time Delay(Secs)

Over Voltage(%)

Time Delay(Secs)

OverVoltage (%)

Time Delay(Secs)

1 765 Bilaspur - Sipat # 1 109 5 150 0.1 above 98% NTPC2 765 Bilaspur - Sipat # 2 109 7 150 0.1 above 98% NTPC3 765 Gwalior - Agra - I 108 5 150 0.1 NRLDC4 765 Gwalior - Agra - II 109 7 150 0.1 NRLDC5 765 Sasan - Satna -I Sasan 109 5 150 0.16 765 Sasan - Satna -II Sasan 108 7 150 0.17 765 Solapur - Raichur # 1 110 5 150 0.1 above 98% SRLDC8 400 Amaravati (India bulls) - Akola Indiabulls 110 6.75 150 0.19 400 Asoj - SSP 110 8 140 0.15 NCA

10 400 Asoj - Wanakbori 115 5 140 Instanteneous GETCO11 400 Asoj-Pirana-1 110 5 150 0.1

12 400 Asoj-Pirana-2 110 6 150 0.1

13 400 Bableshwar - SPTCL II 110 5 150 Instantaneous MSETCL

14 400 Chandrapur - II - Dhariwal-I 110 6 150 0.10 MSETCL

15 400 Chandrapur - II - Switching-I 110 5 150 0.10 Under construction

16 400 Chandrapur - II - Switching-II 110 7 150 0.10 Under construction

17 400 Chandrapur-PGCIL Ckt - 1

18 400 Chandrapur-PGCIL Ckt - 2

19 400 Chandrapur-PGCIL Ckt - 3

20 400 Chandrapur-PGCIL Ckt - 4

21 400 Essar (Mahan) - Korba #1 110 - 150 0.1 above 98% 110 3 140 0.1 above 98%

22 400 Hadala - Jetpur 110 3 130 0.05 GETCO

23 400 JP Bina - Bina JP Bina MP

24 400 JP Bina - Bina (PG) JP Bina 110 4 150 0.125 400 Kansari-Adani-1 110 3 150 0.126 400 Kansari-Adani-2 110 4 150 0.127 400 Kansari-Adani-3 110 5 150 0.128 400 Kansari-Adani-4 110 6 150 0.129 400 Kansari-Bhinmal 110 5 150 0.130 400 Kansari-Kankroli 110 4 150 0.131 400 Karad - Jaigad-I 110 4 150 Instantaneous MSEGCL32 400 Karad - Jaigad-II 110 6 150 Instantaneous MSEGCL33 400 Kasor - GPEC 110 6 120 or 140 0.05 GETCO34 400 Kasor - Rajgadh-1 110 3 or 4 130 or 150 0.05 or 0.1 Check35 400 Kasor - Rajgadh-2 110 5 130 or 150 0.05 or 0.1 Check36 400 Kasor - SSP 110 4 or 5 130 or 140 0.05 NCA37 400 Khedamara - Korba Ext - I 113 4 130 Instanteneous CSPGCL38 400 Khedamara - Korba Ext - II 118 4 140 Instanteneous CSPGCL39 400 Koradi (New) - Indiabulls (Amaravati) 110 5 150 0.15 Indiabuls40 400 Koradi-Sarani (PGCIL) 110 5 150 041 400 KWPCL - Raigarh KWPCL 110 6 150 0.1 above 98%42 400 Lonikand (MSETCL) - PGCIL 110 5 150 0.05 Check43 400 Mundra (APL) - Sami - I 110 4 150 0.1 0.95 GETCO / APL44 400 Mundra (APL) - Sami - II 112 5 150 0.1 0.95 GETCO / APL45 400 New Koyna - Jaigad - II 110 6 150 Instantaneous MSEGCL46 400 New Koyna - Jaigad - I 110 4 150 Instantaneous MSEGCL47 400 Raigarh - Jarsuguda # 1 112 5 150 0.1 above 98% ERLDC48 400 Raigarh - Jarsuguda # 2 111 5 150 0.1 above 98% ERLDC49 400 Raigarh - Starlite # 1 110 5 150 0.1 above 98% ERLDC50 400 Raigarh - Starlite # 2 110 7 150 0.1 above 98% ERLDC51 400 Raipur - KWPCL 110 5 150 0.1 above 98% KWPCL52 400 Raita - Korba 110 4 130 Instanteneous CSPTCL / NTPCCheck53 400 Raita - Marwa 110 4 130 Instanteneous CSPTCL54 400 Sasan - Jabalpur Sasan 110 5 150 0.10

Stage IIS. No. Line (End -I & End II)

Stage I Stage II Stage IVoltage

55 400 Singaji - Chehgaon MPPTCL MPPTCL

56 400 Singaji - Pitampur MPPTCL MPPTCL

57 400 Vindhyachal - Jabalpur - III 110 5 140 0.1 110 5 150 0.1058 400 Vindyachal - Sasan 110 5 140 0.1 Sasan59 400 Vindyachal - Vindyachal (Pooling) #1 NTPC NTPC60 400 Vindyachal - Vindyachal (Pooling) #2 NTPC NTPC61 400 Vindyachal- Essar (Mahan) #1 110 5 140 0.1 above 98% 110 - 150 0.1 above 98%62 400 Waluj - Aurangabad (PGCIL) 110 6 150 0.163 400 Waluj - Pune-1 (PGCIL) 110 5 150 0.164 400 Waluj - Pune-2 (PGCIL) 110 5 150 0.165 Bina - BPSCL 120 5 Check66 Damoh - Birsinghpur-(MPPTCL line) 110 5 150 0.10 MPPGCL there r 2 lines but given one line67 Dehgam – Jhanoor – 1 110 4 150 0.10 NTPC68 Dehgam – Jhanoor – 2 110 5 150 0.10 NTPC69 Gandhar - Navsari # 1 NTPC 110 5 150 0.1070 Gandhar - Navsari # 2 NTPC 110 6 150 0.1071 IEPL - Wardha - I IEPL 110 5 150 0.172 Indore - ISP 1 110 5 125 Instantaneous NHDC73 Indore - ISP 2 110 6 130 Instantaneous NHDC74 Jhanor - GPEC NTPC GPEC75 JPL - JPL Tamnar 2 NA76 JPL - JPL Tamnar 3 NA77 JPL - JPL Tamnar 4 NA78 Katani - Birsingpur 1 108 5 120 Instantaneous MPPGCL79 Katani - Birsingpur 2 108 5 120 Instantaneous MPPGCL80 Mauda - IEPL (PGCIL) - I 110 5 140 0.1 0.98 IEPL81 Nagda - ISP 110 4 125 Instantaneous NHDC82 Pithampur - Malwa - I 110 5 125 Instantaneous MPPTCL83 Pithampur - Malwa - II 110 6 125 Instantaneous MPPTCL

84 Pune - Aurangabad (MSETCL) # 1 110 5 150 0.10 above 98% MSETCL

85 Pune - Aurangabad (MSETCL) # 2 110 7 150 0.10 above 98% MSETCL86 Pune - Lonikand (MSETCL) 110 5 150 0.10 above 98% MSETCL Check87 Raigarh - Bhudipadar CSPTCL ERLDC88 Raigarh (Kothra) - Durg (Raipur)89 Sugen - Jhanor SUGEN JHANOR90 Sugen -Pirana (Torrent) SUGEN 110 5 130 0.191 Sugen -Un Sugen SUGEN UNSUGEN92 Unosugen - Pirana 150 5 130 0.193 UnoSugen-Pirana(Torrent) UNOSUGEN 110 5 130 0.194 Vapi - Sugen 110 5 150 0.10 Torrent95 ZANOR – Ambheti (Vapi) Check96 Zerda - Bhinmal 110 5 150 0.10 NRTS - I97 Zerda - Kankroli 110 5 150 0.10 NRTS - I98 400 Parli (MSETCL - Girwali) - Parli (PG) I (Main- 1& 2) 110 7 & 5 150 100 ms WR I99 400 Parli (MSETCL - Girwali) - Parli (PG) II (Main- 1&2) 110 7 & 5 150 100 ms WR I

100 Pirana (Torrent) - Pirana (PG) 2 PIRANA OFF OFF PGCIL101 Pirana (Torrent) - Pirana (PG) 2 PIRANA OFF OFF PGCIL102 220 Auriya - Malanpur NRLDC MPPTCL103 220 Auriya - Mehgaon NRLDC MPPTCL104 220 Badod - Kota MPPTCL NRLDC

105 220 Badod - Modak MPPTCL NRLDC

106 220 Korba(E) - Bhudipadar # 2 CSPTCL ERLDC

107 220 Korba(E) - Bhudipadar # 3 CSPTCL ERLDC

108 220 Mundra - NaniKhakhar D/C 110 5 150 0.1 0.98 GETCO109 220 Mundra - Tappar D/C 110 5 150 0.1 0.98 GETCO110 220 Tarapur- Boisar No settings No settings

HCL

Typewritten text

Annexure - 10.5.3