13th pcc minutes

7/27/2019 13th PCC Minutes

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EASTERN REGIONAL POWER COMMITTEE14, GOLF CLUB ROAD, TOLLYGUNGE

KOLKATA-700033

MINUTES OF THE 13th PROTECTION SUB-COMMITTEE MEETING HELD AT ERPCKOLKATA ON 08.08.2012 (WEDNESDAY) AT 11:00 HOURS

List of participants are enclosed at Annexure-I.

Member Secretary I/C, ERPC welcomed the participants and mentioned that there wamajor grid collapse in Eastern Region (except CESC system) along with NR & NER system a13:01Hrs of 31.07.2012. So before taking up the agenda items, ERLDC was requested tmake a brief presentation on the above grid disturbance and its restoration proceduresThen SE (PS), ERPC was requested to take up the agenda points in seriatim.

PART A

ITEM NO.:1 CONFIRMATION OF THE MINUTES OF THE 12th PROTECTION SUB-COMMITTEMEETING OF ERPC HELD AT ERPC, KOLKATA ON 26.03.2012

The minutes of the above meeting were circulated vide letter no. ERPC/S(PS)/ PROTECTION/ 2012/ 411- 444 dated 13.04.2012.

No comments have been received from any constituent.

The minutes of the meeting may be confirmed.

The minutes of the 12th Protection sub-committee was confirmed withouany modification.

PART B NEW ITEMS

ITEM NO.1 FAILURE OF PLCC (BPL MAKE) FOR 400KV SAGARDIGHI TPS-SUBHASGRAS/C LINE WBPDCL AGENDA

BPL make PLCC of SgTPS-Subhasgram S/C line remained out of service sincelong for which the protection and speech channels was not working butremained with constant alarm. The failure details as well as the presentalarm indications at SgTPP end panels are as follows:-Channel-1: a)CARR. ALARM AT 95 MODEM CARD

b)RX ALARM AT MEMRI-HP CARD

Channel-1 : a)CARR. ALARM AT 95 MODEM CARDb)RX ALARM AT MEMRI-HP CARD

SPEECH : ALARM INH AT 95 SPIN V3 CARDAs healthiness of PLCC (Protection & Speech) is very vital for any 400 KV linethe issue may be deliberated for immediate remedial measures.WBPDCL & POWERGRID may please elaborate.

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Deliberation in the meeting

For evacuation of power from Sagardighi TPS WBPDCL LILO of 400 kFSTPS-Subhasgram S/C at Sagardighi PS was made. This LILO work (aroun11km) along with procurements/installations of Bay-equipments wer

undertaken by WBPDCL. The work was executed through POWERGRID as deposit work. Accordingly, two sets twin channel BPL make PLCC panels accessories were procured. and installed at both ends of 400 kV SgTPSSubhasgram S/C line. The existing PLCC panel (ABB make) at SubhasgramS/S end was shifted to SgTPP end and fitted for 400 kV SgTPS-FSTPS lineAt present, the PLCC channels for 400KV SgTPS-Subhashgram line sectioat Subhasgram S/S end are not working properly. As per PGCIL, the PLCpanel at Subhasgram S/s has been malfunctioning since October,2010. Osome occasions minor rectification jobs were undertaken by PGCIL. But ithe present case, PGCIL expressed their inability to do the necessarrectification to sort-out the problems at Subhasgram S/s as to their view

PLCC panels at Subhasgram S/S are the property of WBPDCL.

WBPDCL on the other hand viewed that since Subhasgram S/S and FSTPS/S are within the operating arena of PGCIL/NTPC, it would not be feasiblto it for carrying out rectification work at Subhasgram S/S by encroachinothers control area. Representative from WBPDCL has also envisagesimilarity to such type of problems in case of 400KV SgTPPParulia D/line(when in operation)

In absence of Powergrid representative to comment on this issue, MembeSecretary I/C, ERPC proposed for convening a joint meeting to resolve thissue, with concerned utilities during September, 2012.

ITEM NO.2 ANALYSIS & DISCUSSION ON VARIOUS GRID INCIDENCES WHICH OCCURRED ICTU / STU SYSTEMS DURING THE PERIOD BETWEEN APRIL,2012 TJUNE,2012 Reports submitted by ERLDC

Agenda submitted by ERLDC on various grid incidences during the above periois incorporated at Annexure-II).

Respective constituent members may please explain and intimate thremedial measures taken.


It wasinformedthat reports of most of the disturbances (except JSEBwere received from the constituents. On completion of studies ananalysis of the same reporting will be made before next PCC.

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WBSETCL representative informed that the overvoltage setting of 400 kVBakreswar-Jeerat line at Jeerat end was adopted recently as decided inthe previous meeting. Member Secretary I/C impressed upon all theutilities including POWERGRID, NTPC to ensure proper coordination ofovervoltage settings of the 400 kV transmission lines in consultation withERLDC for grid security point of view.

ITEM NO.3 TRIPPING OF FSTPP UNIT # 2,3,4,5 OF NTPC AND 400KV FSTPP-KHSTPP LINES -I,II,III & IV ON 16.03.12(Item No. B.4 of MoM of the 12th Protection sub-Committee)

On 16.03.12 at 19:58 hrs, while charging 400 KV FSTPP-KhSTPP-IV from

FSTPP end (first time charging from FSTPP end), FSTPP#2,3,4,5 trippeon back up earth fault protection. 400 KV FSTPP-KhSTPP-IV tripped oSOTF and 400 KV FSTPP-KhSTPP-III tripped on Distance protectionzone-II from FSTPP end and direct trip received at KhSTPP end. 400 KFSTPP-KhSTPP-I & II tripped from KhSTPP end only due to back uearth fault protection. 400 KV FSTPP-Sagardighi tripped fro

Sagardighi end only. This incident caused approximately 1300 MWgeneration loss alongwith loss of no. of important grid elements.

After detailed discussion during 12th PCC meeting, NTPC was requeste

to carry out analysis of the incident particularly on delayed operatioof SOTF and failure to open the CB in coordination with M/s AREVA ansubmit a detailed report including DRs etc. within a fortnight.

The detailed report of the incident was received on 4 th June, 201

from Farakka, NTPC. Relay setting and PSL of main-I & II, LBB I & Relays were reviewed, relays were once again configured and testewith the help of M/s AREVA. Other remedial actions were also takebut non-operation of line protection of Z2 /Z3 would be taken up witrespective remote sub-station.( Refer Detailed Report of FSTPS aAnnexure-III)FSTPP, NTPC may please elaborate and members may please discuss.


Based on the report submitted by NTPC, ERPC observed that whilcharging of the 400 kV Farakka-Kahalgaon Ckt.-IV, the line CBs of all othelines from FSTPS were kept open and entire load was put on bus coupleCB. This might not be a good proposition and need further deliberationNTPC further clarified that when the line was charged, it got tripped o

SOTF and that was due to mal-operation of the relay. The relay wareconfigured and tested by M/s. AREVA and OEM Engineers. FSTPS, as remedial measure, suggested that in case of closing of lines emanating oufrom generating stations , remote end breakers shall be closed first and the operation holds then breakers(CB) at generating stations will bclosed. But the suggestion was not acceptable to ERLDC. Aftedeliberation, it was agreed that as per the IEGC, the Grid operator woul

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decide the end of charging and closing of a line and this will be binding bthe utilities.

ITEM NO. 4 INTERMITTENT FAILURE OF MAIN-I-CARRIER PROTECTION CHANNEL IN RESPECT OF400KV FARAKKAJEERAT CIRCUIT AT JEERAT END

(Item No. C.2 of MoM of the 12th Protection sub-committee)

WBSETCL earlier expressed concern over frequent outages of Main-I protectio

channel of the 400kV Farakka Jeerat line at Jeerat end and the Main-II protectiochannel of the said circuit remained out of service since 01.09.2010 . However, thprotection channel-I was restored on 05.12.2011 as reported by Powergridbut Main-II protection is reportedly yet to be attended. During the previouPCC meeting, Powergrid agreed to restore the PLCC panel Main-II channeshortly. WBSETCL raised the issue of Main-II restoration of the above line.

Powergrid may please intimate the present status.


WBSETCL informed that protection channel of Main-II of 400 kV FarakkaJeerat line still under outage and POWERGRID is yet to take up the workIn absence of Powergrid representative, it was decided to take up thissue at monthly OCC level.

ITEM NO. 5 STATUS OF AUTO-RECLOSER FACILITIES ON IMPORTANT 400KV TRANSMISSIOLINES (BOTH CTU & STU)(Item No. C.3 of MoM of the 12th Protection sub-committee)

400kV Tala-Binaguri line (Tala HPA / POWERGRID)

ERLDC requested Tala authorities to put the single phase auto- reclosur

feature in service at Tala end. THPA would not face any difficulty upon itimplementation rather it reduces switching over voltages and improvstability etc. BPCL representative agreed to discuss with THPA as well as M/sBHEL and explore the possibility of implementing single phase auto-reclosefacility at Tala end. It was learnt that M/s. BHEL had no objection putting thsingle phase auto- reclosure in service of the above line.

As decided earlier the issue was regularly discussed in OCC meetings

ERLDC requested THPA to provide more data for detailed study anfurther analysis.

THPA, BPCL and ERLDC may update the present status.


ERPC expressed concern over the delay in putting the auto recloser enablfacility at Tala end.Tala representative informed that some of their engineers have beetrained at PRDC, Bangalore and the matter is expected to be taken u

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soon. As Powergrid representative was not available, it was decided thathe issue would be deliberated in the OCC meeting.

ITEM NO. 6 PROCUREMENT AND INSTALLATION OF NUMERICAL RELAYS BY JSEB FOR LALMATSUBSTATION

(Item No. C.4 of MoM of the 12th Protection sub-Committee)

The need to install numerical relays, in place of the existing one was fe

for Lalmatia S/stn., which JSEB agreed to expedite its procurement and iinstallation during 20th TCC meeting.

ERPC vide its letter dated 06.03.2012 impressed upon Member (Tr.) o

JSEB for early procurement and installation of numerical relays at the abovsub-stations as per the decision of 20th TCC meeting. The information awaited.

JSEB may intimate the present status.


It was decided that the issue would be put up for deliberation in the TCmeeting, as representative of JSEB was not present.

ITEM NO. 7 SPS FOR Sterlite Generation(Item No. C.5 of MoM of the 12th Protection sub-committee)

Modification of SPS of Sterlite Proposed by ERLDC

400 KV Rourkela-Raigarh ckt-IV IS LILOed at Sterlite thereby making 400 KSterlite-Rourkela and Sterlite-Raigarh 2nd line which were taken into servicon 17/07/12 at 17:59 hrs and 20:49 hrs respectively.

It is proposed to take both 400 KV Sterlite-Rourkela and Sterlite-Raigar2nd line under the ambit of SPS implemented by Sterlite.

Regarding SPS for Mejia B and MPL, ERLDC is in opinion that the present networ

configuration would allow the power evacuation through LTOA as well as its owabsorption as embedded system. Hence, no SPS is proposed for implementation.

Sterlite and DVC and may please opine.


Sterlite representative informed that since the loading capacity on 400 kSterlite-Rourkela and Sterlite-Raigarh is 650 MW each, the provision of SPS aframed up earlier need to be modified to restrict the power flow on the lines.In view of recent grid disturbance it was agreed that all the three units (600MWeach) of SEL along with 2 nos 400KV outgoing lines have to be taken intconsideration in the system studies and the SPS as well as Islanding schemes oSEL shall be devised accordingly.

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ITEM NO.8 REPLACEMENT OF PLCC SYSTEM OF 400 kV TSTPS (NTPC) -ROURKELA ANTSTPS (NTPC) - RENGALI D/C(Item No. C.6 of MoM of the 12th Protection sub-committee)

PLCC system and protection coupler (BPL-make) of the aforesaid lines ha

become obsolete and not-availability of spare support has made difficult tmaintain the healthiness of the PLCC system.

The replacement of the PLCC system at the remote ends (Rourkela & RengaS/S of POWERGRID) is also involved for matching PLCC

POWERGRID was requested (vide letter dt. 05.04.2011) to revert bac

regarding the replacement and the modality. NTPC agreed to place the PLCorder and would send the technical specification to Powergrid.

It was informed that the replacement work of PLCC system of the above line

is in progress and would be completed by 2012

In the previous meeting, NTPC informed that contract proposal foprocurement of PLCC systems on behalf of POWERGRID for Rourkeland Rengali ends of 400 kV TSTPP-Rourkela and TSTPP -Rengali linerespectively has already been initiated in February, 2012.

POWERGRID & NTPC may please intimate the progress of the work.


NTPC representative informed that the issue was discussed with Powergriand work order is likely to be placed in August,2012. The deliveryschedule of equipment is about 4 to 5 months. The new PLCC is expectedto be in place by 31st March, 2012.

ITEM NO. 9 COMMISSIONING OF BUS BAR PROTECTION AT RAMCHANDRAPUR AN

CHANDIL 220 KV SUB-STATION OF JSEB(Item No. C.7 of MoM of the 12th Protection sub-committee)

In the 18th TCC meeting held on 30.06.2011 at Ranchi it was decided that a grouwith representation from ERLDC, ERPC, Powergrid and JSEB would study thfeasibility of installation of bus bar protection at Ramchandrapur & Chandil 220 ksub-stations of JSEB.

The group visited the above sub-station on 14.11.2011 and 15.11.2011 and submittethe report. The report suggested that the bus bar protection is feasible if spare corof the CT with high knee point voltage is available at Ramchandrapur S/S and SparCT core as well as interposing CT is made available at Chandil S/s.

On the basis of the report, JSEB agreed in the 20 th TCC meeting to explore thpossibilities of bus bar protection at both the above sub-stations.

JSEB may please apprise the present status.


As no representative from JSEB was present, it was decided that the issuewould be taken up in the next TCC meeting.

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ITEM NO. 10 ZONE 3 SETTINGS OF TRANSMISSION LINE(Item No. C.8 of MoM of the 12th Protection sub-committee)

For some of the important lines Zone 3 settings have to be reviewed so that thwould not conflict with emergency loading of the lines. The emergency loa

capability would give the Operator sufficient time to take corrective action, buif such loading can lead to load encroachment of Distance Relays in Zone 3, themergency situation would worsen and may lead to cascading of outageFurther, power swing blocking philosophy also needs to be revisited in the light orecent grid disturbances.Constituents were requested to submit protection settings of transmission elementof important grid elements and the sample format prepared by ERLDC was given fosubmission.All members were impressed upon in the last meeting to furnish the information, irespect of their own transmission systems.

Meanwhile, WBPDCL submitted the detail protection available and its present settin

of the lines emanating from the power stations of Kolaghat, Santaldih, Bakreswaetc. It is suggested to provide the Zone-2 & 3 settings of the remote sub-statioconnected with the above power stations.

Members may like to discuss.


Member Secretary I/C, ERPC mentioned that as transmission lines are beinallowed to be loaded to higher and higher levels, the subject of load-carryincapabilities of transmission lines is becoming increasingly important. So, thencroachment of load into the zone-3 characteristics of distance relays is one o

the main causes for the mal operation of the relays.

ERLDC viewed that for some of the important lines Zone-3 setting need to be tbe reviewed so that this would not conflict with emergency loading of the lineIn the wake of the recent grid disturbances on 30.07.12 and 31.07.12, it habecome essential to review the Zone 3 settings of all the important lines iEastern Region as well as the ties with Western, NER and Northern Regions. It important for the system operator to be able to estimate the level of loadinwhich can lead to load encroachment of Distance Relays in Zone-3, so thacascading outages of transmission lines can be prevented and emergencsituation is avoided. Further, power swing blocking philosophy also needs to brevisited in the light of recent grid disturbances.

The matter was discussed in the 10th, 11th ,12th and 13th Protection subCommittee meetings of ERPC and members were requested to furnish details oDistance Protection settings particularly Zone-3 of their respective lines. OnlWBPDCL has furnished the details so far.

Constituents are therefore once again requested to furnish the following detaifor each 400kV line within their control / jurisdiction as per the format fofurther review and necessary protection coordination by ERPC/ERLDC:

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1 Line name and ckt. number

2 Line length & voltage Km, kV

3 Conductor type

4 Zone-3 setting for Phase fault reach in ohms as well as % of line impedance5 Zone-3 timer setting for phase fault msec

6 Zone-3 setting for ground fault reach in ohms as well as % of line impedance

7 Zone-3 timer setting for phase fault msec8 Action on detection of Out-of-step condition Trip / Block9 Timer for out-of-step condition sec

ITEM NO. 11 Islanding scheme for Thermal Power plants(Item No. C.9 of MoM of the 12th Protection sub-committee)

I. Islanding Scheme for Sagardighi Thermal power StationII. Islanding Scheme for BakreswarThermal power Station

The above islanding schemes were discussed in the previous meeting

Members agreed to examine the proposed scheme and revert back with thviews.As regards the islanding schemes of Bakreswar and Sagardighi TPSs proposein the 10th PCC meeting, WBPDCL informed that although no islanding schemis in place at present for Bakreswar TPS, house load operation with one unwas already tested. Such mode of operation will be activated when thsystem frequency dips to 48 Hz. Regarding the proposed islanding schemesboth WBPDCL and WBSETCL felt that the feasibility of implementation shoulbe discussed in a separate meeting between themselves. It was decided tfinalize islanding schemes for Sagardighi and Bakreswar TPS before thensuing ERPC meeting.

WBPDCL & WBSETCL / SLDC may please intimate.


WBPDCL representative infomed that there was a meeting amonWBSETCL, WBSEDCL & SLDC for framing the Islanding plan of BakreswaTPS with 220kV BkTPP-Satgachia D/C line having 250MW minimum an380MW maximum load and Sargardighi TPS with 220kV SgTPP-Gokarna D/line with minimum loading of 250 MW. Accordingly, the logic of thislanding Scheme is under preparation and discusion with the Planauthorities are going on. Once the scheme is framed the plan will also b

discussed at ERPC forum before implementation. Member Secretary I/CERPC suggested WBPDCL to make the draft scheme prepared for discussioin the next OCC and TCC meeting. WBPDCL agreed to the suggestion.ERLDC also requested WBPDCL to explore the revival of islanding plan oBandel TPS with Adisaptagram load.

ITEM NO. 12 Islanding scheme of CPPs

(Item No. C.10 of MoM of the 12th Protection sub-committee)

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In the previous meeting M/S Tata Power informed that WBSETCL has alreadapproved their proposal for islanding of one 120MW unit of Haldia CPP witlocal load. Implementation details are being worked out.

TATA Power & WBSETCL may highlight the final plan of islanding scheme.

A no. of CPPs are connected to the OPTCL system through 400 KV, 220 KV an132 KV lines. Some of these CPPs like NALCO, ICCL and RSP have theiislanding scheme in place which is recorded in Recovery procedures prepareby ERLDC and the same successfully operated during grid disturbancoccurred in the past. However, details of islanding schemes of other CPPs iother states of ER are not available with ERLDC.In view of above, action may be taken by SLDCs to furnish the details oislanding schemes of CPPs under their jurisdiction to ERLDC for including thsame in Recovery procedures in the event of a major disturbance involving Egrid, the surviving CPP islands should be in a position to extend startup poweto their nearest power stations. If any commercial and technical constrain

exists for availing start up power from these CPPs, the same may have to bresolved.

SLDC / OPTCL may please intimate the present status.


It was informed that the islanding plan implemented at Tata Power, Haldidid not survive during recent grid disturbance. As the Tata representativwas not present, it was decided to discuss the matter during next OCmeeting. ERPC also requested OPTCL to send the details of Islandinschemes of CPPs connected to OPTCL networks. GM,ERLDC requested t

the concerned authorities to expedite submission of the details.

ADDITIONAL AGENDA POINTS

ITEM NO. 13 Audit of UFR relay

As per section 5.2(n) IEGC, RPC Secretariat shall carry out periodic testing oUFR relays. In the special IEGC meeting held on 15.07.10, it was agreed thaProtection sub-Committee will decide method for testing of correctness oUFR relay setting and the periodicity if inspection. It will also constitute small group to carry out inspection.

In the 7th

Protection sub-Committee held on 12.08.10,the sub-Committeagreed to constitute a sub-group from ER for the audit of UFE relayAccordingly, utilities were agreed to nominate their representative in thsubgroup. Nominations were received from following constituents:

I. Smt. Arundhati Ghosh, Addl.CE(Testing) WBSETCLII. Shri Swapan Maity, DGM(OS), WBPDCL

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III. Shri S.J.Lahiri,CM(OS), PowergridIV. Shri G.Mitra, DGM, ERLDCV. Shri A.Sengupta, Sr.Dy.Manager, CESC

The quantum of load to be shed at different stage of setting by each of Econstituent as agreed in the 1st TCC meeting of ERPC held on 18.10.2006 wa

implemented in ER which is still continuing. In the 10th

Protection Committemeeting held on 12.08.2011, it was proposed to connect twice the loarequired to the feeders having under frequency relays installed (considerinthe load factors of feeders). Accordingly, the details of load to be shed in Econstituents as different stages are indicated below:

Systems Stage-I (48.5 Hz) Stage-II (48.2 Hz) Stage-III (48.0 Hz)

Approved Actual Approved Actual Approved Actual

BSEB 30 MW 70 MW 36 MW 42MW 43 MW NIL

JSEB 17 MW 26 MW 12 MW 13 Mw 22 MW 38 MW

DVC 56 MW 51 MW 55 MW 61 MW 82 MW 127 MWODISHA 77 MW 77 MW 77 MW 77 MW 105 MW 105 MW

WESTBENGAL(includingCESC)

120 MW 197MW 120 MW 191MW 164 MW 226 MW

Total 300 MW 461 MW 300 MW 384MW 410 MW 486MW

In addition, DVC and West Bengal connected UFRs set at 47.6 Hfor emergency load shedding corresponds to 973 MW for 132 KV feeders.

In the 74th OCC meeting, constituents agreed to change the UFR setting as under:

Stage Changed Setting Earlier Setting

Stage-I 48.8 Hz 48.5 Hz

Stage-II 48.6 Hz 48.2 Hz

Stage-III 48.2 Hz 48.0 Hz

It was also emphasized that this change is only in respect of frequency settinand quantum of load shedding as indicated above to be enforced though UFwould remain unchanged till further review of the issue as whole in thproposed Joint Meeting of all NEW grid members.

In view of change setting of UFR relays, Protection sub-Committee maapprise its UFR Audit team about the revised setting, so that audit can bcontinued on revised setting.


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On the query of Member Secretary, I/C, ERPC, WBSETCL, CESC and BSEconfirmed the change of above frequency setting of UFR in therespective systems. BSEB stated that the changes made after the Grifailure on 31.07.2012. DVC and OPTCL agreed to change the setting, buOPTCL required one month time to complete as the UFRs are undedifferent Distribution companies and located at remote areas. It wa

decided that JSEB would be requested to complete setting change withione month time. The audit of UFR would start from next month afteobtaining concurrence from ensuing TCC meeting. The issue would bplaced in the TCC meeting.

ITEM NO.14 REVIEW OF OVERVOLTAGE RELAY SETTING (STAGE-I & STAGE-II) FOEXISTING 400KV CTU /STU LINES


Member Secretary, ERPC emphasized the need to review the over voltagrelay settings ( both Stage-I & II ) of the 400 kV transmission lines betweethe utilities. All constituents including NTPC, POWERGRID, POWERLINKwere requested to compile the information at their respective end anforward the same to ERLDC and ERPC for further review & obtain thconcurrence.

ITEM NO. 15 DATE AND VENUE OF THE NEXT (14th) PROTECTION SUB-COMMITTEEMEETING

The next (14th) Protection sub-Committee meeting will be held during the end ofDecember, 2012.

The meeting ended with vote of thanks to chair.

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Annexure

List of Participants in the 13th Protection sub-Committee meeting of Eastern Region held on 08.08.2012

(Wednesday) at ERPC, Kolkata

Organisation Name Designation Contact Numbe

BSEB Shri S.K.SENGUPTA ESE, KOLKATA 9836020195

Shri S.B.PRASAD EEE, CRITL, PATNA

OPTCL Shri S .S. NANDA MANAGER 9438356128

Shri P.K.BHUYAN MANAGER 9937329699

WBSETCL Shri SABYASACHI ROY SE(TESTING) 9432316727

WBSETCL,SLDC Shri A.RAICHAUDHURI Addl. CE/SLDC 9433419696

Shri A.BISWAS Addl. CE/SLDC 9239292572

WBPDCL Shri S.MAITY DGM (OS) 9432021168

CESC Shri A.GHOSAL Dy. Chief Engineer(Testing) 9831054664

SEL Shri M.K.PANDA JHARSUGUDA 9777457222

DGPC,THP Shri TSHEWARY JAMTSHO Engineer

Shri CHOEDRA SR. SECTION OFFICER

DGPC,KHP Shri ZANGPO HEAD,MTC DIV.DGPC,CHP Shri TEAZIM DORJI DIVISIONAL ENGINEER

NTPC Shri RAKESH KUMAR DGM(OS), ERHQ-I 9431011344

Shri SANJIB K SUAR DGM (EMD), TSTPS 9437042781

Shri R.P.SINGH Sr.Manager (OS), ERHQ-I 9431011366

NHPC Shri N.YUGANDHAR ASST. MANAGER 9800003819

ERLDC Shri U.K.VERMA GM 8902496220

Shri P.MUKHOPADHYAY AGM 9433041810

Shri D.K.SRIVASTAV AGM 9433041802

Shri G.MITRA DGM 9433041811

Shri S.BANERJEE CM 9433041823

Shri T.R.MOHAPATRA DGM 9433041873

Shri M.K.THAKUR SR.ENGINEER 9432351832Shri S.K.SAHAY Engineer 9432351832

ERPC Shri A.K.BANDYOPADHYAY Member Secretary I/C 9433068533

Shri J. BANDYOPADHYAY SE ( C) 9432326351

Shri B.SARKHEL SE (PS) 9433065724

Shri V.KALANARAMEN EE 033-24233015

Shri S.M.JHA EE 9748216566

Shri G.GHOSH EE 9051221331

Shri S.P.DATTA DGM (NTPC) 9433067022

Shri S.PAUL EE 9874929946

Shri S.KEJRIWAL EE 9831919504

Shri S.ROY AD-I

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ANNEXURE-

SYSTEM /

SUB-STATION

DATE & TIME

INCIDENCE RESTORATION DELIBERATION ON

FOLLOWING POIN

Rangit HEP

220/132kV

Siliguri S/s

06/04/12 12:20hrs.

At 12:20hrs, 132kV Rangit-Siliguri

(PG) tripped on earth fault & over

current (DP, R-Ph, Z-I, 40.84 km fromRangit). 132kV Siliguri-Melli also

tripped. 132kV Rangit-Ramam was inopen condition due to problem at

Ramam end. At that time only Unit-2

of Rangit was on bar. Sudden electrical

jerk & high fluctuation of frequency

was observed .The same unit was

tripped due to load generation

mismatch. 132kV Gangtok-Rangit,

132kV Gangtok-Melli & 66kV Rangit-

Ravangla lines were manually opened

from Rangit end.

i) 132 KV Rangit Siliguri normalized at

12:53 Hrs

ii) 132 KV Rangit - Gangtok normalized at13:10 Hrs

iii)132 KV Gangtok Melli normalized at13:32 Hrs

iv)132 KV Siliguri Melli normalized at

13:00 Hrs

v) 66 KV Rangit Rabangla normalized at

13:05 Hrs

vi)Rangit Units #2 Synchronized at 13:03

1. Reason for tripp

132 KV Siligu

S/C2. Remedial m

taken

JSEB system

10/04/12 at

15:38 hrs.

At 15:38hrs, all the lines & ICTsemanating from 220/132kV

Ramchandrapur S/s tripped due to

Stormy / Inclement weather in JSEB

system. There was 140MW load throw

in Adityapur area. Following elements

were tripped.

i) 400/220kV, 315MVA ICT-I &

II at Jamshedpur S/s (back upO/C relay operated).

ii) 220 KV Chandil

Ramchandrapur

iii) 132 KV Ramchandrapur

Adityapur-D/C

iv) 220/132kV, 150MVA Tr-1 &

2 at Ramchandrapur

v) 220kV Joda-Ramchandrapur

220 KV Chandil Ramchandrapurnormalized at 16:43hrs.

220kV Joda-Ramchandrapur normalized at

17:05hrs.

Both 220/132kV, 150MVA Tr-1 & 2 at

Ramchandrapur charged at 17:08hrs.

400/220kV, 315MVA ICT-I normalized at

16:45hrs.

400/220kV, 315MVA ICT-II normalized at17:29hrs.

132 KV Ramchandrapur Adityapur-D/C

declared breakdown due to conductor

snapped at loc-27/28.

1. Details of tripp

available.

2. It appears

non/improper

operation of line

transformer tripp

3. Remedial m

taken

400/220/132kV

Arambagh S/s

of WBSETCL

system

13/04/12

at 10:31hrs

At 10:31 hrs, bus fault occurred at

220kV bus of Arambagh S/s of

WBSETCL system due to which all400kV, 220kV & 132kV following

lines & ICTs connected to Arambagh

got tripped. Power supply failed at

220kV Midnapur S/s & its connected

132kV substations such as Khargapur,

Jhargram, Pingla, Balichak, Hizli &C.K.Road.Power supply also

interrupted in 132kV substationsconnected to Arambagh such as Rayan,

Birsingha, Tarakeswar, Belmuri &

Adisaptagram.BEL(CPP) which was

generating 10MW power got

tripped.CESC system got split from

Howrah source.

Hizli S/s got power from EGRA S/s via 132kV

Hizli-EGRA ckt at 10:35hrs.C.K.Road s/s got power from old Bishanpur at10:37hrs.Midnapur S/s got power from C.K.Road at

10:45hrs.Pingla & Balichak S/s got auxiliary power fromMidnapur source at 10:51hrs.Kharagpur S/s got power from Midnapur at

10:47hrs.Jhargram S/s got auxiliary power at 10:50hrs.Adisaptagram S/s got power via 132kV BTPS-Adisaptagram-I at 10:40hrs.

Belmuri S/s got power form Adisaptagram at10:45hrs.

Tarakeswar got auxiliary power from Belmurisource at 10:50hrs.

220kV Arambagh bus got power from Domjurvia 200kV Arambagh.-Domjur-II at 10:44hrs

1. Operation of B

differential op

led to tripping

2. Remedial M

taken

14


15/25

315MVA ICT-I charged at 10:50hrs.

132kV bus at Arambagh charged via 160MVATrs at 10:51hrs.

400kV Arambagh-Durgapur ckt charged at10:52hrs400kV Arambagh-Kolaghat ckt charged at10:51hrs.

400kV Arambagh-PPSP-I charged at 11:14hrs.315MVA ICT-III charged at 11:00hrs.315MVA ICT-II charged at 11:06hrs.220kV Arambagh-Midnapur-I & II charged at

11:00hrs.220kV Arambagh- New Bishanpur-D/C chargedat 10:56hrs.200kV Arambagh.-Domjur-I charged at 11:55hrs

220kV Arambagh-Rishra charged at 11:01hrs132kV Arambagh-Tarakeswar-D/C charged at11:17hrs.132kV Arambagh-Rayan-D/C charged at

11:05hrs.132kV Arambagh-Birsingha-D/C normalized at

11:07hrs.

CESC sytem again connected at Howrah

point at 10:39hrs.DVC system

18/04/12

at 11:10 hrs

At 11:10hrs, a very high resistive E/Foccurred in C-Ph (bottom conductor) in

200kV CTPS (old)-Dhanbad (L-204)

line (may be due to touching of trees

underneath the Line204).The above

line tripped through distance protection

at both end(C-Ph,D/O/C & D/E/F relay

at CTPS end & Z-1 at Dhanbad end).

D/E/F relay of 220kV CTPS (N)-Dhanbad (L-203) at CTPS (N) end had

seen the E/F current = 1.05 In (CT

Ratio 800/1A), but the fault loci didnt

enter instantaneously (but after a timedelay of approx. 500ms) into the 1st

zone impedance locus of the Dhanbad

end distance relay of L-204, due to the

resistive nature of the fault. So, D/E/F

relay of L-203 finally tripped after

620ms. L-204 was normalized at11:15hrs.

At 11:15hrs, a resistive E/F

occurred in C-Ph in 220kV CTPSB-

BTPSB (L-205/206). (May be due to

touching of trees).The said tripped line

tripped from both end (Z-1 at CTPS &

Z-3 at BTPS). At the time of tripping

the fault currents of L-205 were asfollows:

IA = 485 A

IB = 513 A

IC = 2003A

IE = 1566A

I neg. Seq. = 1480 A

After tripping of L-205 all the

loads shifted to L-206.But It was

i) 220 KV BTPSB- Jamshedpur D/C normalized at 11:55 & 12:25 Hrs

ii) 220 KV BTPSB-CTPSB- D/C

normalized at 11:50 & 11:51 Hrs

iii) 220 KV Dhanbad-Mithon(PG)-D/C

normalized at 11:15 & 11:25 Hrs

iv) 220 KV CTPS(A)- Dhanbad

normalized at 11:16 Hrs

v) 220 KV CTPS(B)- Dhanbadnormalized at 11:25 Hrs

vi) 220 KV BTPSB-Ramgarh-D/C

normalized at 11:30 & 11:31 Hrs.

vii) 220 KV Jamshedpur-Joda normalizedat 11:40 Hrs.

viii) BTPSB U#1 synchronized at

17:41hrs.

ix) CTPSB U#7 synchronized at

19:20hrs.

Early commissioninsecond tie line b

CTPS (N) and CTP

to strengthen the

and reliability o

system.

2) The sequence

disturbances/occurrecan be analyzsed p

only when the distu

records downloade

different relays synchronized throug

time synchronization

3) All the 220KV

emerging from

houses should haveaided protection wit

reclose facility.

4) The Static YTG

Line#204 at CTP

should be relac

present day relay.

5) In case of single

between CTPS(OCTPS(N) , the secu

reliability of

becomes week.

6) Vide letter n

(CTC)/T-31/05 dat

04-2012 ne

remedial action

mentioned .

15


16/25

tripped due to transient fault fromCTPS (N)(C-Ph,Z-1 distance

protection). At the time of tripping the

L-206 currents were as follows:

IA = 855 A

IB = 893 A

IC = 1995A

IE = 1254A

I neg. Seq. = 1186 ABoth the running units of

CTPS got tripped due to over speed (no

power evacuation was possible). After

tripping of both lines L-205 & L-206

total load of Jamshedpur, Mosabani,

Chandil, and Gola was fed from BTPS

Unit-1 and from Joda Tie (through

Line#215).220kV Jamshedpur-Joda tir

also tripped on R-ph,O/C. After

tripping of Joda Tie at Joda end, Unit-1

of BTPS could not be able to cater the

total system load of Jamshedpur,Mosabani, Chandil, and Gola and

finally BTPS Unit-1 tripped through

high furnace pressure.

7) Immediate trimmtrees underneath

L#203/204 & L#2

should be taken up.

1. Action on suggmeasure.

2. Strengtheof DVC system.

JSEB system

20/04/12

at 01:15 hrs

At 01:15hrs, total power

failure occurred at 220/132Kv Chandil

S/s in JSEB system due to Y-Phase CTburst in 220kV Santaldih-Chandil bay.

Due to this all 220kV controlling panel

got disturbed & all the lines & ICTs

emanating from 220/132kV Chandil S/s

tripped. Around 200MW load was

affected in Golmuri,Rajkharswan &Maniqui area. Following elements were

tripped.vi) 220kV Chandil-

Ramchandrapur(Z-2,Tripping

relay type UHA 186X at

Ramchandrapur & Z-2 & Z-

4,E/F,O/C at Chandil)

vii) 220kV Ranchi-Chandil

viii) 220kV Chandil-Santaldih

ix) 132kV Chandil-Rajkharswan

x) 132kV Chandil-Hatia

xi) 132kV Chandil-Adityapur

xii) 132kV Chandil-Golmuri D/c

220kV Chandil-Ranchi normalized at

02:01hrs.

132kV ChandilManiqui (Railway supplyfeeder) normalized at 02:07hrs.

132kV ChandilGolmuri D/c normalized

at 02:09hrs

132kV Chandil-Rajkharswan Charged at

11:19hrs.

220 KV Chandil Ramchandrapurnormalized at 12:55hrs.

132kV Chandil-Adityapur charged at14:50hrs.

132kV Chandil-Hatia charged at 15:08hrs.

220kV Chandil-Santaldih remained on

outage for CT replacement work.

1.CT bursting of

Chandil led to bu

at Chandil.

2.Remedial m

taken

400/220kV

Jeerat S/s of

WBSETCL

system

22/04/12

at 23:30hrs.(refer Exhibit-

II)

At 23:30hrs, B-Phase CT of 400kV Bus

Transfer Bay burst causing fire hazard

& total power failure at Jeerat

S/s.Supply interrupted in adjacent S/s

i.e.

Dharampur,Kalyani,Titagarh,Bonga,De

bogram,Rajatrhat,Ashoknagar,Basirhat,

KLC,

Bongaon & Debogram availed power supplyfrom Krishnanagr source at 23:50hrs.Dharampur S/s got power from Bakreswar at23:43hrs.

Power extended to Titagarh from Dharampur at23:56hrs.Kalyani got power from Dharampur at 23:43hrs.Power extended to Jeerat from Dharampur at

00:00hrs.

1. CT burst of 4

Transfer bay led

fault at Jeerat

2. Remedial m

taken

16


17/25

132kV Kasba-Saltlake-II charged at 00:5hrs.

Rajarhat got power from Subhashgram at00:45hrs.

Ashoknagar & Basirhat availed power fromJeerat at 00:35hrs.Barasat got power from Jeerat at 00:12hrs.At Jeerat..

Feeders/ICTsRestore time (hrs.)

315MVA ICT-I 05:48(23.04.12)315MVA ICT-II & III 00:10

160MVA Tr-I 01:15(via bus transfer)160MVA Tr-II 00:10160MVA Tr-III 00:46400kV Jeerat-Kolaghat 05:55(23.04.12)

400kV Jeerat-Bakreswar 00:57400kV Jeerat-FSTPP 00:20400kV Jeerat-Subhashgram 06:54220kV Jeerat-Kasba-I 01:53

220kV Jeerat-Kasba-II 01:54220kV Jeerat-KLC 01:58

220kV Jeerat-Rajarhat 12:14(23.04.12)132kV Jeerat-Barasat-D/C 00:51 & 00:52

132kV Jeerat-Ashoknagar-II 00:35132kV Jeerat-Bongaon-II 01:55

132kV Jeerat-Dharampur-II 00:01220kV Jeerat-Satgachia-D/C 06:07 & 06:09132kV Bakreswar-Dharampur-T/C 23:43,23:46 & 23:48

132kV Bakreswar-Kalyani 00:24

400 KV Barh

S/S(NTPC) on

09.05.12

09/05/12

at 21:16 Hrs.

On 09.05.12 at 21:16 400 KV Barh kahalgaon I main bay (Bay No.30) Y Ph Ct

blasted( Breaker 3052 tripped on E/F and

breaker 3152 tripped on teed protection) leads

to tripping of all lines emanating from 400 KV

Barh S/S. During occurrence of CT blast all

lines at receiving end (other end barh) tripped

through zone -2 distance protection. The faultis fed by Barh kahalgaon Line Itill line

tripped and as per DR the duration of the fault

was 900 ms.

Restoration time (Date)

400 Kv Barh Kahalgaon I

15:46 (10.05.12)

400 Kv Barh Kahalgaon II

00:45(10.05.12)

400 Kv Barh Patna I 15:06

(10.05.12)400 Kv Barh Patna I 23:17

(09.05.12)

400 Kv Barh Balia - II02:11(11.05.12)

400 Kv barh Balia - II 00:59

(10.05.12)

1.Operation of

protection shoul

sent carrier aid

signal to remote

for accelerated tr

2.Remedial m

taken

220/132kV

Budhipadar S/s

of OPTCL

system

28/05/12

at 14:44hrs.

At 14:44hrs, there was a flash

over on one of the loaded Smelter

feeders line side Isolator at VAL

(Vedanta) CPP switchyard. The said

Smelter feeder was isolated

immediately due to action of protectionsystem. All the CPP units and IPP(Sterlite) unit # 2 tripped due to voltage

dip & 220kV Budhipadar-VAL-I & II

tripped at both ends on distance

protection resulting in station black out.

Simultaneously both the units of IBTPS

tripped. 220kV Budhipadar-Raigarh

Ckt tripped at Raigarh end.

Startup power was given to VAL from

Budhipadhar substation at 15:29hrs.

At 15:29 hrs 220 kV Budhipadar-VAL Ckt-

I charged at VAL end.

At 15:30 hrs 220 kV Budhipadar-VAL Ckt-II charged at VAL end.

At 15:46 hrs 220 kV Budhipadar-Raigarh

Ckt charged.

At 19:20 hrs IBTPS U#2 synchronized togrid.

At 21:10 hrs IBTPS U#1 synchronized to grid.

1. Reason for tripp

IB units

2. Unsuccessful

loading operati

Sterlite#2

3. Remedial m

taken

17


18/25

JSEB system

28/05/12

at 12:41 hrs

At 12:41hrs, total power failureoccurred at 220/132kV Chandil S/s in

JSEB system operation of LBB relay. It

is reported that jumper of 132kV

Chandil-Adityapur line at loc-35

snapped & caught fire. The above said

line was tripped form Adityapur end

but didnt trip at Chandil end. Due to

this 220kV bus tripped & all the lines& ICTs emanating from Chandil S/s

got tripped. Around 170MW load was

affected in Golmuri,Rajkharswan &

Maniqui area.

Power extended to Chandil fromRamchandrapur at 13:21hrs.

220/132kV Tr-I & II charged at 13:22hrs.

132kV Chandil-Manique & 132kV Chandil-

Golmuri-D/C closed at 13:23hrs.

220kV Chandil-Santaldih charged at

13:37hrs.

220/132kV Tr-III charged at 14:05hrs.

132kV Chandil-Rajkharswan Closed at14:09hrs.


15:09hrs.

132kV Chandil-Hatia closed at 15:20hrs.

132kV Chandil-Adityapur normalized at

12:35hrs of 29.05.12.

1. Fault in 132 KV

led to tripping of 2

systems. Appears to

of improper

coordination.

2. Remedial m

taken.

RANGIT

system

23/05/12

at 17:17hrs.

At 17:17hrs, all three running units of

Rangit hydro power station hand

tripped due to tipping of all outgoing

feeder. Heavy storm, lightening &

rainfall were occurred in Sikkim at that

time.132KV Rangit-Melli line trippedon distance protection (21 AB), Z-

1,964m from Rangit end.132kV

Siliguri-Melli tripped on O/C &

E/F.132kV Gangtok-Rangit,132kV

Gangtok-Melli were out of service due

to no voltage & no power

condition.132kV Rangit-Rammam alsotripped. There was loss of load around

60 MW at Sikkim area.

132KV Siliguri-Melli charged from siliguri

end at17:59hrs.

132kV Gangtok-Melli charged at 17:59hrs.

Rangit U#1, 2 & 3 synchronized

at17:555hrs, 17:58 & 18:00hrs respectively.

132KV Gangtak-Rangit normalized at17:42hrs.

132KV Rangit-Melli normalized at hrs on

27.10.11.

132KV Rangit-Rammam normalized at

18:54hrs.

1. Inclement weath

led to occurran

transient E/F in the

220/132kV

Budhipadar S/s

of OPTCLsystem

28/05/12

at 14:44hrs.

(Refer Exhibit-I)

At 14:44hrs, there was a flash

over on one of the loaded Smelter

feeders line side Isolator at VAL(Vedanta) CPP switchyard. The said

Smelter feeder was isolated

immediately due to action of protection

system. All the CPP units and IPP

(Sterlite) unit # 2 tripped due to voltage

dip & 220kV Budhipadar-VAL-I & IItripped at both ends on distance

protection resulting in station black out.

Simultaneously both the units of IBTPS

tripped. 220kV Budhipadar-Raigarh

Ckt tripped at Raigarh end.

Startup power was given to VAL from

Budhipadhar substation at 15:29hrs.

At 15:29 hrs 220 kV Budhipadar-VAL Ckt-

I charged at VAL end.

At 15:30 hrs 220 kV Budhipadar-VAL Ckt-II charged at VAL end.

At 15:46 hrs 220 kV Budhipadar-Raigarh

Ckt charged.

At 19:20 hrs IBTPS U#2 synchronized togrid.

At 21:10 hrs IBTPS U#1 synchronized to

grid.

1.Reason for trippin

units

2.Unsuccessful

loading operatio

Sterlite#2

3.Remedial measure

JSEB

28/05/12

at 12:41 hrs

At 12:41hrs, total power failure

occurred at 220/132kV Chandil S/s in

JSEB system operation of LBB relay. It

is reported that jumper of 132kVChandil-Adityapur line at loc-35

snapped & caught fire. The above said

line was tripped form Adityapur end

but didnt trip at Chandil end. Due to

this 220kV bus tripped & all the lines

Power extended to Chandil from

Ramchandrapur at 13:21hrs.

220/132kV Tr-I & II charged at 13:22hrs.

132kV Chandil-Manique & 132kV Chandil-Golmuri-D/C closed at 13:23hrs.


13:37hrs.220/132kV Tr-III charged at

14:05hrs. 132kV Chandil-Rajkharswan

Closed at 14:09hrs.220kV Chandil-Ranchi

1.Fault in 132 KV


systems. Appears

case of improper

coordination.

2. Remedial m

taken.

18


19/25

& ICTs emanating from Chandil S/sgot tripped. Around 170MW load was

affected in Golmuri,Rajkharswan &

Maniqui area

normalized at 15:09hrs.132kV Chandil-Hatia closed at 15:20hrs. 132kV Chandil-

Adityapur normalized at 12:35hrs of

29.05.12.

BSEB

(Biharsariff)

System

29/05/12

at 19:50 hrs

At around 19:50hrs power supply failed

at 220/132kV Biharsariff S/s in BSEB

due to tripping of all three

400/220kV,315MVA ICTs on back up

over current protection at

Biharsariff(PG) end. 220kVBiharsariffFatuha, 220kV Biharsariff

Tenughat lines were also

tripped.132kV Barhi-Biharsariff line

tripped on SOTF.

400/220kV, 315MVA ICT-I, II & III

charged at 20:06, 20:14 & 20:17hrs

respectively.

220/132kV, 150MVA ICT- I & II was

charged at 20:07 & 20:09hrs.

220kV Biharsariff-Fatuha-I & II charged at20:11 & 20:15hrs.

220kV BiharsariffTenughat charged at

20:23hrs.

220kV Biharsariff-Bodhgaya-II charged at

20:42hrs.

132kV Biharsariff-Hatidah-I & II charged at

20:40 & 20:35hrs respectively

132kV Biharsariff-Bariparai-D/C charged at

20:16hrs.

132kV Barhi-Biharsariff charged at

20:41hrs.132kV Biharsariff-Ekangarsarai-I charged

at 20:25hrs.

1. In absence of d

relay indication, it

from available infor

that fault in 132 K

had not been clea

concerned relay

clearance of fau

400/220 KV ICT,

need to be avoid

future.

2.Remedial measure

JSEB system

03/06/12

at 12:06hrs

(Refer Exhibit-II)

At 12:06hrs, total power

failure occurred at 220/132kV Chandil

S/s in JSEB system due to operation of

LBB relay. It is reported that there was

a transient earth fault in 132kV

Chandil-Rajkharswan line. But thebreaker on both the end didnt open.

Due to this 220kV bus tripped & all the

lines & ICTs emanating from Chandil

S/s got tripped. Around 135MW loadwas affected in Golmuri,Rajkharswan

& Maniqui area.

Power extended to Chandil from

Ramchandrapur at 12:18hrs.


12:27hrs.

132kV Chandil-Rajkharswan Charged at

12:31hrs.132kV Chandil-Hatia charged at 12:35hrs.


12:39hrs

132kV Chandil-Manique & 132kV Chandil-Golmuri-D/C charged at 13:23hrs.

132kV Chandil-Adityapur normalized at

12:56hrs.

132kV Chandil-Golmuri-D/C charged at

12:18hrs.

132kV Chandil-Manique charged at12:18hrs.

LBB operation at 1


line. Similar incide

taken place in Cha

earlier occasion

Need

investigation

subsequent re

measure.

BTPS & CTPS

in DVC system

11/06/12

at 11:57 hrs

At 11:57hrs, 220kV CTPS (old)

Kalyaneswari-D/C, L-61(220 kV

DTPS-CTPS) line tripped due to earth

fault resulting wide imbalance between

load & generation. Around 180MWpower supply from MTPS via

Kalyaneswari was disrupted causing

drop in frequency below 48.5hz.CTPSU# 7 & 8 tripped through frequency

protection. To compensate the

imbalance load, drawal from Joda was

increased more than 100MW for which

220kV Jamshedpur Joda line was

tripped on Directional over current

i) 220kV BokaroB-Jamshedpur-D/C

normalized at 13:10Hrs

ii) 220kV Jamshedpur Joda charged at

13:05hrs.

iii)220kV CTPS (old) Kalyaneswari-IInormalized at 14:55hrs.

iv)CTPS U#2 &3 synchronized at 16:40 &

17:40hrs respectively.v) CTPS U#7 & 8 synchronized at

21:27hrs.

vi)CTPS U# 8 synchronized at 07:50hrs on

15.06.12.

vii) BokaroB U#1 synchronized at

20:25hrs on 14.06.12.

1.S/D of two no 2

line from CTPS(n

CTPS(old) had

weakened the

Further tripping separation of

internal system

subsequent collap

part of DVC syste

to load gen

mismatch.

2. With the addit

generation in DVC

220 KV network

19


20/25

protection.Due to this abnormalsituation CTPS U#2 & 3 tripped on

back up impedance protection. BTPS U

#1 tripped through turbine trip.

viii) 132kVDTPS-CTPS-I charged at12:35hrs.

ix) 132kVDTPS-CTPS-II normalized at

12:10hrs on 12.06.12.

further strengthenin

400/220/132kV

Arambagh S/s of

WBSETCL

system

14/06/12 at

04:34hrs.

(refer Exhibit-

III)

At 04:34hrs, fire hazard

occurred in newly commissioned

315MVA Tr-4 at Arambagh S/s. Due to

this bus fault occurred all 400kV,

220kV & 132kV following lines &

ICTs connected to Arambagh gottripped. Power supply failed at 220kV

Midnapur S/s & its connected 132kV

substations such as Khargapur,

Jhargram, Pingla, Balichak, Hizli &

C.K.Road.Power supply also

interrupted in 132kV substations

connected to Arambagh such as Rayan,

Birsingha, Tarakeswar & Belmuri.

C.K.Road S/s got auxiliary power form old

Bishanpur at 04:40hrs.

Tarakeswar & Belmuri S/s got power form

Adisaptagram at 04:40hrs & full load is

allowed.

Midnapur S/s got power from C.K.Road &old Bishanpur at 04:56hrs.

Pingala,Jhargram, Balichak & Khargapur

got power from Midnapur S/s at 05:00hrs.

Rayan S/s got auxiliary power from 33kV

Sadarhut feeder at 05:20hrs.

Birsingha S/s got auxiliary power from

33kV Sultannagar feeder at 05:25hrs.

220kV Arambagh-Midnapur-I & II charged

at 05:28hrs.

132kV Arambagh-Rayan-D/C charged at

05:45hrs.132kV Arambagh-Tarakeswar-D/C charged

at 05:45hrs.

132kV Arambagh-Birsingha-D/C

normalized at 05:55hrs.

315MVA ICT-4 was declared breakdown.

Fault in

commissioned

Transformer had

tripping of bus a

feeders. Invest

report may be subm

400/220/132kV

Meramundali

S/s of OPTCL

system

16/06/12

at 22:37hrs

(refer Exhibit IV)

At 22:37hrs, due to inclement

weather condition in Meramundali area

all 400kV,220kV & ICts emanatingfrom Meramundali grid sub-station

tripped with a total load loss of

800MW approximately. 220kV

Meramundali-Kaniha-I & II trippedalong with NALCO ckt.-II.220 kV bus-

II at Meramundali became dead.

At 22:38hrs. 400kV

Meramundali-Mendhasal tripped on

over voltage. While charging the line at

23:01hrs it did not hold.At 22:50hrs 220kV

Meramundali-TTPS-D/C, 220kV

Meramundali-Bhushan-D/C, 220kV

Meramundali-NALCO-I tripped and

220kV Meramundali-Bhanjanagar-D/C

hand tripped to avoid power flow from

southern zone.220kV bus-I atMeramundali became dead.

At 23:31hrs 400kV Baripada-

Mendhasal-D/C, 400kV Baripada-

Rengali, 400kV Baripada-Kharagpur

ckt trip on over voltage.

At 23:33 hrs 220kV

Bhanjanagar & Narendrapur supply

failed due to failure of total power

supply at Theruvali sub-station.

At 23:55 hrs 220 kV Theruvali-Jaynagar

Ckt-II charged and power supply extended

to Bhanjanagar.At 23:59 hrs 220 kV supply resumed at

Chandaka, but due to overvoltage to the

tune of 270 kV 40 MVA Trf-II, Auto-2, 3 &

4 tripped. Incoming breaker at Chandakahand tripped.

17.06.12

At 00:02 hrs 132 kV Meramundali-Chainpal

Ckt-II breaker closed at Meramundali to

avail 132 kV power supply for the station

transformer. But due to mechanical problemin 33kV side breaker of station transformer,

the station supply could not be resumed.

At 00:06 hrs 220 kV Theruvali-Jaynagar

Ckt-I charged

At 00:18 hrs 220 kV Theruvali-Indravati

Ckt-4 charged.

At 00:20 hrs Baripda (PG) extended powersupply to Mendhasal through 400kV ckt.-I.The ckt tripped at Mendhasal while closing

the breaker at 00:26 hrs.

At 00:30 hrs 220 kV Theruvali-Bhanjanagar

Ckt-I charged.

At 01:22 hrs 220 kV Theruvali-Narendrapur

Ckt-I charged.

At 02:00 hrs 400 kV Meramundali-GMR-

Kaniha Ckt-I charged.

1. Reason for total

failure at Meram

needs

investigation

2. Remedial m

taken.

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21/25

After investigation, it wasfound that the earth wire of 220kV

Meramundali-Kaniha Ckt-I & II

snapped between Loc. No-13 and 17

and fallen on ground. R- insulator of

220kV Meramundali-NALCO Ckt-II

damaged at Loc. No-41.

Power supply failed at

Theruvali, Bhanjanagar, Chandaka,Narendrapur, Bidanasi, Duburi,

Balasore, Bhadrak and Paradeep

command area.

At 02:10 hrs 400kV Baripada PG-Mendhasal ckt.-I hand tripped from

Baripada (PG) due to high voltage (438kV)

At 02:15 hrs Puri availed power supply

from Narendrapur end through Chandaka.

At 02:24 hrs 400 kV Meramundali- Kaniha

Ckt-II charged.

At 02:32 hrs ICT-I connected to 400kV

Bus-I charged and 220kV bus-I charged atMeramundali.

The delay was due to delay in charging

from Kaniha end and non-availability of tie

breaker at Meramundali and low breaker

pressure at Meramundali.

At 02:35 hrs 220 kV Meramundali-Bidanasi

Ckt charged.

At 02:36 hrs 220 kV Meramundali-NALCOCkt-I charged.

At 02:40 hrs 220 kV Meramundali-Bhusan

Ckt-I & II charged.

At 02:44 hrs 220 kV Meramundali-NALCO

Ckt-I charged.At 02:50 hrs ICT-II at Meramundali

charged.

At 02:59 hrs 220 kV Meramundali-Kaniha

Ckt-I charged.

At 03:00 hrs Chandaka availed powersupply from Bidanasi end and power supply

resumed at Chandaka command area.

At 03:03 hrs 220 kV Mendhasal-Chandaka

Ckt-II charged.

At 03:23 hrs 400 kV Meramundali-

Mendhasal Ckt charged.

At 06:23 hrs 220 kV Meramundali-Duburi

Ckt-I charged.At 07:04 hrs 220 kV Balasore- New Duburi

Ckt charged from Balasore end.

At 07:47 hrs ICT-II at Mendhasal charged.

At 08:50 hrs station supply restored at

Meramundali S/S.

At 10:36 hrs 400 kV Baripada-Mendhasal

Ckt-I charged.

At 11:59 hrs 400 kV Meramundali-JeyporePG ckt charged.

At 12:45 hrs 220 kV Meramundali-TTPS

Ckt-I charged.

At 12:53 hrs 220 kV TTPS-Meramundali

Ckt-II charged.At 13:15 hrs 220 kV Bhanjanagar-

Meramundali Ckt-I & II charged.

At 18:02 hrs 220 kV Meramundali-Duburi

Ckt-I charged.

At 18:47 hrs 220 kV Meramundali-KanihaCkt-II charged.

At 20:08 hrs 220 kV Meramundali-NALCO

Ckt-II charged.

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22/25

BTPS in DVC

system

20/06/12

at 10:45 hrs

At 10:45hrs, a high resistive fault

occurred in R- of 220kV CTPS (new)

BTPS-II (L-206) with fault current

just more than 1.6kA.The fault current

increases when a distance Z-1,R--G

fault detected at CTPS (new).The same

fault was detected at BTPS end & wascleared from both side in Z-1 time.At the same time, a high resistive fault

also occurred in R- of 220kV CTPS

(new) BTPS-I (L-205) with fault

current 1.6kA initially. The fault

persisted for next 260ms.Further the

fault current increase causing a phase to

phase (R-Y) fault with ground. This

was detected in Z-1 from both the side

& L-205 tripped.

After tripping of L-205& 206 the entire220kV load of BTPS-B was shifted to

220kV Jamshedpur-Jindal-Joda tie & italso tripped on over current. There was

a wide imbalance between load &

generation in BTPS area & also some

axillary power supply fluctuation

noticed.BTPS units could not cater to

the entire load & both the units tripped.Power supply affected in BTPS-B,

Gola, Ramgarh, Jamshedpur,

Mosabanic & Purulia S/s.

Jamshedpur got power from Joda at

11:00hrs.

220kV CTPS (new) BTPS-I (L-205)


220kV CTPS (new) BTPS-I (L-206)


BTPS U#1 kept out of bar for over hauling.BTPS U#2 synchronized at 03:40hrs of21.06.12.

BTPS U#3 synchronized at 09:57hrs of

22.06.12.

1. Inadequate 220 K

transmission syst

leads to frequent

disturbance in D

2. Remedial Measu

taken

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23/25

Exhibit

Disturbance in 220/132kV Budhipadar S/s of OPTCL system

Exhibit-

Disturbance in 400/220kV Jeerat S/s of WBSETCL system

Graph

Disturbance in JSEB system

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25/25

13th pcc minutes

Documents