पता / Address List - Kar · 2017. 7. 26. · Transformer/ Reactors/ Surge Arrestors/ Circuit Breakers/ CT's/ PT's/CVT's) like Insulation Resistance (IR) test, Winding Resistance

पता सच Address List

1 मख य अभयता (एचपीसी व जल परयोजना) एपीजनको 4वी मिजल गणदल वजयवाडा आ amp 520004 Chief

Engineer (Generation) APGENCO 4th

Floor Vidyut Soudha Eluru Road Gunadala Vijayawada AP ndash 520

2 मख य अभयता (परयोजना) एपीजनको 4वी मिजल गणदल वजयवाडा आ amp 520004 Chief Engineer (Projects)

APGENCO 4th

Floor Vidyut Soudha Eluru Road Gunadala Vijayawada AP ndash 520 004

3 मख य अभयता (आईपीसी व वयत ampणाल-) एपीान स को3र- मिजल गणदल वजयवाडा आ amp 520004 Chief

Engineer (IPC amp Power Systems) APTRANSCO 3rd

Floor Vidyut Soudha Eluru Road Gunadala

Vijayawada AP ndash 520 004

4 मख य अभयता ( उत पादन) ट-एसजनको हदराबाद Chief Engineer (Generation) TSGENCO Hyderabad

5 मख य अभयता (परयोजना) ट-एसजनको हदराबाद Chief Engineer (Projects) TSGENCO Hyderabad

6 मख य अभयता (वयत ampणाल-) ट-एसान स को हदराबाद Chief Engineer (Power System) TSTRANSCO

Hyderabad

7 मख य अभयता (इल6डज़ाईन) कपीसीएल ब8गलर Chief Engineer (Ele Designs) KPCL Bangalore

8 मख य अभयता ( आर ट- और आर amp डी) कपीट-सीएल ब8गलर Chief Engineer (RT and RampD) KPTCL

Bangalore

9 मख य अभयता एसएलडीसी कपीट-सीएल ब8गलर Chief Engineer SLDC KPTCL Bangalore

10 मख य अभयता (एमट-एस) टनजोडको चन न Chief Engineer (MTS) TANGEDCO Chennai

(Fax No 044 ndash 28585804)

11 मख य अभयता (जल वयत) टनजोडको चन न Chief Engineer (Hydro)TANGEDCO Chennai

(Fax No 044 ndash 28553356)

12 मख य अभयता (सर=ण एव सचार) ट- एन ई बी चन न Chief Engineer (Protection amp Communication)

TANTRANSCO Chennai

13 मख य अभयता (पारषण) ampणाल- ampचालन एचएमट- कालोनी कएसईबी कलमस सर--683503 Chief Engineer

(Transmission) System Operation HMT Colony KSEB Kalamassery-683503

14 अधी=क अभयता- वयत वभाग 137 एनएससी बोस साल पदचर-- 605001 Superintending Engineer ndashI

Electricity Department 137 NSC Bose Salai Puducherry ndash 605001 (Fax No 0413-2331556)

15 जी एम ( ampचा व अन) द=- पावरEFड सकदराबाद GM (OampM) SR-I PGCIL Secunderabad

16 जी एम ( ampचा व अन) द=- पावरEFड ब8गलर GM (OampM) SR-II PGCIL Bengaluru

17 महाampबधक (ओ एस) एनट-पीसी दH=ण =Iीय मख यालय सकदराबाद General Manager (OS) NTPC SRHQ

Secunderabad

18 मख य महाampबधक ट-पीएस - वस तार एनएलसीआईएल नवल- - 607807 Chief General Manager TPS-I Expn

NLCIL Neyveli-607807 (Fax No 04142 ndash 265303)

19 मख य अभयता (पारषण) एनपीसीआईएल मबई Chief Engineer (Transmission) NPCIL Mumbai

20 क8 J Kनदशक कजीएस कगा कनाMटक Station Director KGS Kaiga Karnataka

21 क8 J Kनदशक एमएपीएस कल पक कम Station Director MAPS Kalpakkam

22 क8 J Kनदशक ककएनपीपी KतNनल वल- िजला तमलनाड- 627106 Station Director KKNPP Thirunelveli Dist

TamilNadu-627106

23 Oी पी पी जस ट-न एजीएम (ईएम) एनट-ईसीएल चन न-103 Shri PP Gestine AGM (EM) NTECL Chennai-103

24 Oी एम ampभाकर महाampबधक (amp व अ) एनट-पीएल हाबMर एP टट ततकडी- 628004 Sh M Prabhakar

GM (OampM) NTPL Harbour Estate Tuticorin ndash 628004 (Fax No 0461 ndash 2352842)

25 Oी सयM ampकाश उपाR य= (ampचालन व अनर=ण) जएसडS T य एनजU ल तोरणगT ल बT लार- ndash 583275

Shri Surya Prakash Vice President (Operations amp Maintenance) Ms JSW Energy Ltd Toranagallu

Bellary-583275

26 Oी शाताराम प सह उपाR य= (वयत एव परयोजना) जएसडS T य एनजU ल तोरणगT ल बT लार- ndash 583275

Shri Shantharam Pai Associate Vice President (Electrical amp Projects) Ms JSW Energy Ltd Toranagallu

Bellary-583275

27 Oी आर वी भWए उपाध य= ( ampचालन) यपीसीएल ब8गलर Shri RVBhat Vice President (Operations) UPCL

Bangalore

28 सह उपाR य= ( सर=ण व मीटरग) अदानी पावर ल 8-ए सभव जज भवन क सामन बोदकदव अहमदाबाद-

380015 गजरात Associate Vice President (Protection amp Metering) Adani Power Ltd 8-A lsquoSambhavrsquo

Opp Judgersquos Bungalow Bodakdev Ahmedabad 380 015 Gujarat India

29 Oी Yबयत चZबतU (ampधान वयत एव सी आई अनर=ण) ट-पीसीआईएल [ यानपरम नल तN Fाम मतकर

मडल एसपीएसआर नT लर- 524344 Sh Bidyut Chakraborty (Head Electrical and CampI Maintenance)

TPCIL Pyanampuram Nelaturu Village Muthukur Mandal SPSR Nellore ndash 524344 (Fax No 0861 ndash 305

30 Oी आर एस कमारP वामी सलाहार(वयत) सीईपीएल मलमरडर Fाम ओ]Wपदरम ताT लक ततकडी- 628105

तमलनाड Sh RS Kumaraswamy Advisor (Electrical) CEPL Melamarudur Village Ottipidaram Taluk

Tuticorin ndash 628 105 Tamil Nadu (Fax No 0461 ndash 2614297)

31 Oी ^कशोर आकM ट वर उपाR य= (amp व अ) आईएल व एफएस ट-पीसीएल सी पदपW डाक परनगीपW भवनEगर

ताT लक कडलर िजला तमलनाड- 608502 Sh Kishore Arcot Sr Vice President (OampM) ILampFS

Tamilnadu Power Company Ltd CPudhupettai (post) Parnagipettai Bhuvanagiri Taluk Cuddalore Dist

Tamilnadu ndash 608502 (Fax No 0414-4252991)

32 Oी सS यसाची मखजU वर उपाR य= ( amp एव अ) ]हदजा एनपीसीएल पटग`यड मडल वशाखप`नम आ amp-

530031 Sh Sabyasachi Mukherjee Sr Vice President (OampM) Hinduja NPCL Pedagantyada Mandal

Visakhapatnam AP ndash 530031

33 Oी एस सदरमKतM उपाR य= ( ampचालन) लनको कaडपT ल- पावर लमटड आईडीए कaडपT ल- इbा]हमप`नम मडल

कd ण िजT ला आe ampदश- 521228 Sh S Sundaramoorthy-Vice President (operations) Lanco Kondapalli

Power Limited IDA Kondapalli Ibrahimpatnam Mandal Krishna district Andhra Pradesh-521228 (Fax

No 0866-2872801)

Minutes of the 65th

Meeting of PCSC held on 29th

June 2017 Page 1

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Minutes of the 65th Meeting of Protection Coordination Sub-Committee (PCSC ndash 65) of SRPC held on 29th June 2017

1 Introduction

The 65th meeting of Protection Coordination Sub-Committee (PCSC-65) of SRPC was held on 29th June 2017 at SRPC Secretariat Bengaluru The list of participants is enclosed at Annexure-I Members and Participants were welcomed to the meeting and briefed on the following protection related issues Evaluation of the bids received from various bidders in respect of SRPC project ldquoProcurement of

Web-based Management Software and Protection Setting Calculation Toolrdquo project is under progress by the Bid Evaluation Committee (BEC) of SRPC constituted for the purpose and it is expected that the award for the same would be placed in August 2017

Wrt perturbations experienced at TPCIL plant in Nellore protection audit of Nellore PS (NPS) of PGCIL (SR-I) was conducted during 19 -20 June 2017 Then a special meeting was also convened at TPCIL plant premises on 21062017 It was noted that there was nothing amiss at NPS So the cause of TPCIL perturbations was further analysed by correlating their time-stamps with that obtained from SRLDC and SLDC-APTRANSCO From them it was seen that frequent faults on 400 kV SDSTPS ndash Nellore-AP (Manubolu) DC line were the cause of observed perturbations at TPCIL plant Accordingly certain remedial measures were suggested for the parties involved APTRANSCO APGENCO and TPCIL were requested to take suitable action to comply with the recommendations given

UPCL vide their mail dated 22052017 had proposed a revised SPS at their Udupi plant in place of the existing one to take care of oscillations and power swings that would result under various contingencies All concerned members were requested to take part when the issue is taken up for discussion later in the meeting

It was also informed that in view of the frequent tripping of ICTrsquos at 400220 kV Hoody SS it was proposed to conduct PSAG-18 meeting on 03072017 to ascertain the action taken by KPTCL to attend to various measures that had been suggested by PCSC forum in their previous meetings

Wrt implementing AR on all 220 kV lines amp above it was stated that the action plan including feeder details for implemented AR are yet to be furnished by APGENCO APTRANSCO TSGENCO and TSTRANSCO KPTCL and NTPC-Ramagundam The respective Constituents were requested to furnish the sought details at the earliest and take concrete action towards implementing AR in all 220 kV amp above transmission lines

2 Confirmation of the Minutes of the 64th meeting of PCSC held on 25th May 2017

The minutes of the 64th meeting of PCSC had been circulated vide SRPC letter No SRPCSE-III PCSC-64 20173216 - 51 dated 09062017 As no comments had been received from any of the Constituents the minutes of the 64th Meeting of PCSC were confirmed

Minutes of the 65th

June 2017 Page 2

3 Details of Grid Disturbances (GDrsquos) Grid Incidents (GIrsquos) and Line Trippings due to Auto-

Reclose (AR) failure non-operation amp PLCC mal-operation

The trippings due to GDrsquos GIrsquos AR failure non-operation and PLCC mal-operation that had occurred

during May 2017 were discussed in the Meeting The deliberations and recommendations of the PCSC Forum are enclosed at AnnexurendashII for further needful action The details of the tripping events including relevant PMU plots presented by SRLDC in the meeting are also enclosed at AnnexurendashVI for kind reference

4 Status of pending PCSC Recommendations (P-REC)

The status of implementation of pending PCSC recommendations was discussed in the meeting The

Constituents were asked to take steps to comply with the same and requested to submit the status of their compliance latest by 10082017 The updated status of the same as on 25072017 is enclosed at AnnexurendashIII

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

under forced outage (PRM)

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

taken had not been furnished were discussed in the meeting The Constituents were asked to kindly furnish specific remedial measures action taken covering one or the other items from the following indicative list in time so as to forward the same to Central Electricity Authority

Brief details of line patrolling carried out (with tower location)

Brief details of RoW maintenance (by proper Tree-cutting) resorted to

De-capped insulators replacement

DC earth fault removal

PLCC cards replacement

Relay settings modification

Steps taken to put AR or CB into service after they have been locked-out

Faulty equipment replacement

Reference to OEM in case of equipment failure

Brief Details of tests carried out to ascertain the healthiness of various equipment (Power Transformer Reactors Surge Arrestors Circuit Breakers CTs PTsCVTs) like Insulation Resistance (IR) test Winding Resistance test Capacitance test Tan delta test DGA test Leakage current test CRM DCRM test etc

Any other appropriate remedial measure

The updated list of PRM as on 25072017 is enclosed at Annexure-IV

6 Certificate for Healthiness of Batteries

As per the MoP CEA direction given in pursuant to recommendations of the Enquiry Committee (NEW Grid Disturbance on 30th amp 31st July 2012) RPCrsquos are required to obtain from their respective Constituents a monthly certificate for healthiness of batteries installed at 220 KV amp above voltage level Substations (for power supply to Relays RTUs and PLCC equipment) and furnish the same to CEA MoP

Minutes of the 65th

June 2017 Page 3

With reference to above the Constituents had been requested to submit the certificate on healthiness of batteries on monthly basis (ie status for a month shall be sent by the 7th day of the following month) to SRPC as per the format given below

Station Application Battery Battery Charger Remarks

Station Name

Code Type

(PS SS)

Protection

Communication

Details Status (Healthy Unhealthy)

1 Station-A Protection (Bank-1)

Protection (Bank-2)

Communication (Bank-1)

2 Station-B hellip

hellip hellip hellip

Note 1 Code is the short name of the Station

2 PS ndash Power Station SS - Substation

The sought status for the months of May 2017 had not been received from the following SR-Constituents

TANTRANSCO NTPL amp NTECL

7 Implementation of Line Differential Protection (LDP) in Nellore and Simhadri complexes

The issue had been discussed in the 64th meeting of PCSC held on 25052017 when it was agreed that the concerned Constituents would take steps to implement LDP in both Nellore and Simhadri Complexes by December 2017

Subsequently MEPL (vide their mail dated 14062017) and SEL (vide their mail dated 27062017) informed that in view of their present financial condition they may kindly be exempted for the time being from implementing LDP on the lines belonging to them in Nellore Complex However they assured that suitable action would be taken to implement the same once their situation improves

In this regard it was clarified that PGCIL (SR-I) can go ahead procuring LDP relays without considering MEPL and SEL requirement Accordingly the following Constituents were asked to take appropriate steps to put LDP in place by December 2017

Nellore Complex Constituents responsible for LDP implementation

Timeline for LDP implementation

Line Differential Protection (LDP) to be implemented on all 400 kV lines (lt 50 km)

PGCIL (SR-I) APGENCO APTRANSCO TPCIL SGPL

December 2017

MEPL and SEL As and when their financial healthiness improves

Minutes of the 65th

June 2017 Page 4

Simhadri Complex Constituents responsible for LDP implementation

Line Differential Protection would be implemented in Simhadri Complex on all 400 kV lines inter-connecting Gajuwaka SS Kalpaka SS Simhadri STPP and Hinduja TPS

PGCIL (SR-I) NTPC APTRANSCO and HNPCL

December 2017

8 Installation of PMU by POWERGRID at 400kV NP Kunta

In PCSC-64 meeting held on 25052017 the following was noted

SRLDC stated that NP Kunta is a critical station where in addition to injection of large quantum of solar power reactive power control is also being exercised by way of the recently commissioned STATCOM Thus to better monitor the LVRT effects of Solar power station and functioning of STATCOM installed at NPKunta station it is necessary to have a PMU installed there To this PGCIL (SR-I) informed that provision for PMU at NP Kunta had not been envisaged in Part-I of URTDSM Further as per the decision taken in the 3rd Communication meeting held at SRPC Bengaluru the quantity of Phase-I of URTDSM project was freezed On this SRLDC mentioned that PGCIL need not procure an additional PMU for the purpose instead they can divert the PMU identified for Vijayawada to NP Kunta The issue was further discussed and in view of the stated significance of NP Kunta PGCIL (SR-I) was asked to divert PMU identified for Vijayawada to NP Kunta as part of Phase-I of URTDSM project

However in view of the difficulty expressed by PGCIL (SR-I) in shifting the (already commissioned) PMU and its associated cabling and communication modules from Vijayawada to NP Kunta the issue was again discussed by PCSC forum in the meeting During the meeting the necessity of having PMU at NP Kunta was once again emphasised It was also noted that a PMU had been identified for installation at GMR-Vemagiri as part of URTDSM project in Phase-I However as APTRANSCO and GMR had not agreed for the same the same was not yet carried out In view of above PCSC forum decided that PGCIL (SR-I) take steps to shift the PMU and associated cabling and communication interface modules identified for commissioning at GMR-Vemagiri to NP Kunta and install the same at the earliest

9 Revision of Special Protection Scheme (SPS) implemented at UPCLrsquos plant at Udupi

UPCL vide their mail dated 22052017 requested to review the SPS implemented at their plant in view of the changed grid conditions and furnished a proposal for consideration by SRPC SRLDC

Minutes of the 65th

June 2017 Page 5

In this regard the existing SPS and the proposed SPS by UPCL were discussed Existing SPS Both 400 kV lines unavailable amp Generation gt 650 Trip Unit-2 Both 400 kV line and one of the two 220 kV lines unavailable

amp Generation gt 300 MW Trip Both Units Proposed SPS Under this the following five contingencies have been considered 1 Tripping of one 400 kV line 2 Tripping of one 400 kV line with the other already tripped 3 Tripping of both 400 kV lies simultaneously 4 Overloading of any 220 kV line 5 Tripping of all Lines emanating from UPCL (Zero Power condition) The details of the proposed SPS by UPCL are enclosed at Annexure-V With regard to above it was noted that even though the proposed SPS may effectively take care of the oscillations power swings that may occur at UPCL during above stated contingencies the following concerns need to be properly addressed from the grid perspective Since the line breaker is not allowed to be tripped in the event of occurrence of power swing

(even when it enters Zone-1) and a definite possibility exists for it to be transmitted to the other adjacent connected stations it needs to be shown by conducting proper system studies that tripping of UPCL running Unit (s) by virtue of operation of corresponding SPS would act negatively on the sustenance of the power swing

It was felt that the Contingencies at 2 amp 3 can be combined since they essentially result in the same Further the reference power value assumed for comparing with actual generation to effect tripping of Unit-2 under Contingency-2 may be appropriately revised to 325 MW to avoid overloading of Varahi ndash Shimoga lines (in the extreme case of full generation at Varahi GS)

Study results for all Contingencies considered shall be shared Given the complexity of the proposed SPS issues pertaining to non-reliability of its operation may

also be suitably factored into Accordingly UPCL was requested to review the proposed SPS addressing above concerns and furnish the thus modified scheme to PCSC forum along with supporting study results

10 Auto-Reclosure Implementation on all 220 kV amp above Transmission Lines of

Southern Region

It was noted that APGENCO (Hydro) amp APGENCO (RTTP) are yet to furnish their action plan for implementing AR in their respective networks Similarly though TSGENCO (Thermal) amp TSGENCO (Hydro) had stated that they were coordinating with TSTRANSCO to obtain revised settings they are also yet to furnish Action Plan Time-frame for implementing AR It was also noted that in the Action Plan furnished by APTRANSCO feeder details were not mentioned Similarly in the Action Plan furnished by TSTRANSCO time-frame for implementing AR was not mentioned Action Plan for implementing AR is also yet to be furnished by NTPC-Ramagundam (for Tie-CBrsquos of 400 kV lines)

Minutes of the 65th

June 2017 Page 6

It was further noted that even though KPTCL had furnished the details of 220 kV amp 400 kV lines where AR is already in place the details of 220 kV lines where AR is not presently in service along with Action Plan for implementing same are yet to be furnished

All above Constituents were asked to kindly furnish required details by 08082017

Since the main issues in implementing AR are the adopted conservative protection philosophies lack of proper PLCC communication and breakersrsquo suitability supportability it is intimated in view of above that if there are no issues wrt carrier communication and breakersrsquo supportability concerned Constituents shall make efforts to implement AR immediately in their respective networks Where communication amp breaker related issues stand in the way of implementing AR concerned Constituents shall take steps to address them appropriately on priority basis and implement AR in their respective networks in a phased manner at the earliest

In the previously held PCSC meetings the following logics have been clarified for implementing AR

Normally high speed single-ph single-shot AR scheme (with simultaneous opening at both ends of feeder with a dead-time of 1 sec and reclaim-time of 25 sec) may be used by all Utilities (including Generators)

However those generators (Coal Gas Nuclear Hydro) who have concerns wrt closing on to un-cleared fault can make use of the following time-differentiated single-ph single-shot AR scheme

ldquoIn this after a line has been opened from both ends (generator end amp grid end) on AR operation the grid end will be auto-reclosed as usual after the elapse of its dead-time (say 1 sec) However the generator end relay will check for the line voltage after elapse of an extended dead time say 15 sec [here the additional time delay of 05 sec which has been included as a safety margin shall be so chosen that the extended dead-time is less than the adopted Pole Discrepancy time delay] If the line voltage so sensed is healthy amp normal (which implies that the fault has already been cleared) then generator end will be auto-reclosed else 3-ph trip will be given at generator end to open the other two phase polesrdquo Further wherever Trip-on-Reclose (ToR) feature is available at grid-end station it shall be configured such that it sends Direct Trip (DT) command to generator end upon its operation

It is also clarified that the above scheme can be as it is used to Line-CBrsquos of all bus configurations (including Main-CBrsquos of one-and-half breaker bus configuration) For Tie-CBrsquos in one-and-half breaker configuration employing priority scheme (which also happens to be the recommended practice) above logic is not be required since the employed priority scheme anyway checks for CLOSE_STATUS of Main-CB before closing Tie-CB However if required the above logic can be applied to Tie-CBrsquos also by adopting a suitable extended dead-time considering the remote end stationrsquos AR dead time

It is further clarified that AR functionality for a transmission line shall be preferably put into service using (i) Bay Control Unit (BCU) or (ii) separate External AR Relay Where these are not available only then should the AR functionality of Main protection relays of lines be used

Minutes of the 65th

June 2017 Page 7

Here it is assumed that both Main-relays are deriving their Voltage Input from the Line CVTrsquos (from different cores as per the recommended practice) However if this is not the case and the concerned Utility has a practice of using Line-CVT voltage input to one of the Main relays and Bus-CVT voltage input to the other Main relay it is recommended that voltage input to be used in time-differentiated AR logic shall be exclusively derived from the line-CVT for use in both the Main relays

It is also clarified that AR implementation is not required in case of radial feeders cables amp composite feeders and is optional for the lines interconnecting two generating stations

In addition to above the following logics (applicable to the Cases where AR is being proposed to be implemented from Main Protection Relays) are also intimated for the benefit of the Constituents

Since there are two Main protection relays (Main-I and Main- II) to decide upon proper way of implementing AR for achieving fool-proof AR operation it has been advised that instead of implementing AR from only one of the Main relays (in light of its low success rate) the following Alternatives be considered Alternative ndash 1 AR is implemented and kept functional from Main ndash I [Main-II] only but with feedback from Main-II [Main-I]

In this scheme AR is implemented and kept in service from Main-I [Main-II] as usual

Additionally Main-II [Main-I] relay is configured for single-pole (1-ph) tripping and the OPEN (TRIP) status of the concerned trip relay is used for triggering AR functionality in Main-I [Main-II] By this even if the fault is not sensed in the beginning by Main-I [Main-II] but sensed by Main-II [Main-I] AR operation is guaranteed However it may be noted that in cases of permanent faults this scheme may result in unsuccessful AR operation with Pole Discrepancy Relay coming to rescue if the fault is not sensed by Main-I [Main-II] but by Main-II [Main-I] at the time of auto-reclosing instant

Alternative ndash 2 AR is implemented and kept functional from both Main ndash I and Main-II

In this scheme AR is implemented and kept in service from both Main ndash I and Main-II as

usual As can be seen the scheme is reliable and is without any additional logics However to avoid the possibility of both relays racing for CLOSE-OPEN-CLOSE-OPEN operation in case of permanent faults it shall be ensured that along with other conditions ldquoAR BLOCK with 3-ph TRIPrdquo is also effected for the same phase fault as the original one that occurs during AR dead-time

Out of the above two also it has been suggested to consider Alternative-2 for implementing AR in view of its higher success rate

11 Network Configuration Changes

As per the information furnished by SR-Constituents to the OCC forum in their 132nd meeting (held on

09062017 Minutes circulated on 04072017) it is formed that the following configuration changes (additions deletions modifications of transmission elements) took place in the southern grid during

Minutes of the 65th

June 2017 Page 8

April 2017

Two STATCOMs (+- 50 MVAR Each) at NP Kunta commissioned on 16052017

Kudgi Unit I 72 Hrs trail run completed Successfully

400 kV Shankarapally-Suryapet I amp II commissioned on 05052017

22033kV SS at Hayathnagar IampII in Ranga reddy district of 50 MVA Capacity was commissioned on 03052017 by TSTRANSCO

SR II Power grid vide letter dated 10062017 had informed that consequent to the successful completion of Trial Operation the following assets under transmission system associated with ldquoSystem strengthening ndashXX in Southern Regional Gridrdquo have been put under Commercial Operation wef 0000 hrs of 10062017 in terms of clause 4 of CERC (Terms and Conditions of Tariff Regulations 2014)

1 x 500 MVA 40022033kV ICT at Trichy Substation along with associated bays and equipments

SR I Power grid vide letter dated 04062017 had informed that consequent to the successful completion of Trial Operation the following assets of ldquoTransmission System for Ultra Mega Solar Park in Anantapur Dist Andhra Pradesh- Part ndash A (Phase-I)rdquo have been put under Commercial Operation wef 0000 hrs of 04062017 in terms of clause 4 of CERC (Terms and Conditions of Tariff Regulations 2014)

+- 100 MVAR STATCOM at NP Kunta Pooling Station along with associated bays and equipment

12 Instances of SPS Operation

Based on the information furnished by SRLDC it is informed that there occurred no SPS operations in SR during the period 25052017 ndash 28062017

13 Status of Implementation of Protection Audit Recommendations (Phase-I amp Phase-II)

With reference to the petitions filed by KSEB (88MP2016) and KPTCL (135MP2016) for seeking further time-extension for completing their respective Protection Audit Recommendations (PAR) the final Order of Honrsquoble CERC disposing of petitions was issued on 15122016 In this Order the Commission apart from granting last-chance time-extensions to various SR-Constituents had also directed SRPC to monitor the status of completion of PAR regularly in PCSC meetings and submit bi-monthly report to the Commission confirming the completion of Phase-I and Phase-II of PAR of the Constituents of Southern Region

In this regard based on the information furnished various Constituents a summary table showing the

compliance status of various SR-Constituents as in July 2017 is given below

Constituent

PAR (Phase-I) Activities

PAR (Phase-II) Activities

PAR (Ph-I amp Ph-II) Compliance ()

Remarks

Stipulated Completion

1 APGENCO (Hydel)

31122017 31122017 40 ---

Minutes of the 65th

June 2017 Page 9

2 APGENCO (Thermal)

30072017 --- 75 Based on the status furnished timeline for complying with the remaining pending recommendations (3 in no) is expected by 31122017

3 APTRANSCO 31032017 --- 9571 Out of the 3 remaining pending recommendations two are expected to be completed in three months while the other is expected by 31122017

4 TSGENCO (Hydel)

31032017 31032017 8823 Based on the status furnished timeline for complying with the remaining pending recommendations (4 in no) is expected by 31122017

5 TSGENCO (Thermal)

6 TSTRANSCO 31032017 31032017 8523 Based on the status furnished timeline for complying with the remaining pending recommendations (13 in no) is expected by 30092017

7 KPCL --- 31112016 100 ---

8 KPTCL 31052017 31052017 2817 Based on the status furnished timeline for complying with the remaining pending recommendations (51 in no) is expected by 30092017

9 TANGEDCO 31122017 31122017 6389 ---

10 TANTRANSCO 31122017 31122017 50 ---

11 KSEB 30112016 31122017 9481 ---

12 NPCIL (MAPS) 31012017 --- 8889 Based on the status furnished timeline for complying with the remaining pending recommendation (ONE in no) is expected by 31122017

All above SR-Constituents are requested to adhere strictly to the time-lines given in the Order for

completing their respective pending PAR The IPPrsquos for whom there are pending PAR [viz Spectrum PGL GMR Barge - Kakinada Konaseema GPL APGPCL Vijjeswaram (Stage-I amp Stage-II) amp LANCO-Kondapalli PL] are also requested to complete them at the earliest

Minutes of the 65th

June 2017 Page 10

14 Nomenclature for naming various files uploaded in web-based Tripping Monitoring

System of SRLDC Portal

The nomenclature to be followed by the Constituents in naming various files (FIR DR EL TR) corresponding to a tripping incident was brought out in the SRPC letter No SRPC SE-III PCSC-45 4609 ndash 649 dated 26062015 and in the minutes of PCSC-45 issued vide SRPC letter No SRPCSE-III PCSC-45 2015 5422-455 dated 21072015 As illustrated therein the format to be followed for the user entered part-name is given below

Transmission Element File Name to be given by the user

Transmission Line SSN_DSN_line_FT

Inter-connecting Transformer SSN_ICT_FT

Generating Transformer SSN_GT_FT

Generating Unit SSN_Unit_FT

Where SSN = Source Station Name From end Station Name Sending end Station Name DSN = Destination Station Name To end Station Name Receiving end Station Name FT = File Type (FIR DR EL TR)

All SR-Constituents are requested to kindly intimate the above file naming nomenclature to all the concerned and ensure that it is strictly followed at all the stations in their respective control areas so that tripping analysis can be done systematically

15 Date amp Venue of the next PCSC Meeting

It is informed that the 66th meeting of PCSC will be held on 17th August 2017 (Thursday) from 1030 hrs onwards in the Conference Hall of SRPC Secretariat Bengaluru

Annexure - I

Grid Occurrences discussed in the 65th Meeting of PCSC held on 29th June 2017 132

Analysis of Grid Occurrences - 65

I Details of Grid Disturbances

Details of Event Date amp Time Reason Remarks Category

Complete outage of 230 kV Villianur Substation of Pondicherry

19-05-2017 at 1235 hrs

Triggering incident was failure of CT in 110 kV Villianur-Kurumbapet at Villianur substation 230KV Villianur ndash NLC2 and 230 kV Villianur - Pondy lines got tripped from Pondy end (on operation of DEF) and NLC end (on operation of Zone-3) respectively resulting in loss of supply to 230 kV Villianur substation

Load Loss 140 MW

The single line diagram of 230 kV Villianur SS as furnished by PED is attached at the end 230 kV Villianur ndash Pondy line Villianur (PED) end

As per FIR TR line was kept holding

The following was also stated in FIRTR

Remedial action Relay testing amp calibration proposed during total shutdown on 13062017

DR amp EL not furnished Pondy (PGCIL-SR2) end

As per FIRDRELTR line tripped at 123559270 hrs on B-E fault due to DPR Z3 (98 km 156 kA) operation From DR amp EL Z3 time delay was observed to be about 06 sec

230 kV Villianur ndash NLC2 line Villianur (PED) end

Annexure-II

DR amp EL not furnished NLC2 (NLCIL) end

As per FIRDRELTR line tripped at 123551016 hrs on B-E fault due to DEFR operation From DR amp EL DEFR time of operation was observed to be about 07 sec

Time sync of Protection relays with GPS at NLC TPS-II needed to be ensured SRPC SRLDC

It was noted that the triggering incident was failure of B-ph CT in 110 kV Villianur-Kurumbapet line at Villianur SS

It was noted that for the above fault distance protection at Villianur end on 110 kV Villianur-Kurumbapet line had not operated probably due to absence of current input (hence impedance becoming infinite)

Further since there was no busbar protection to 110 kV buses the fault continued to be fed from the remote ends (Pondy-PG and NLC-2) through 100 MVA Transformers (Txr ndash 1 amp Txr ndash 2)

So the transformersrsquo back-up protections were called into action But since OC protections provided on both HV amp LV sides had no high-set Units and since they were kept non-directional [Relay make ER TJM 10] LV (110 kV) side OC protections of both transformers had acted to give trip command Even though the 110 kV CB of Txr ndash 1 got opened that of Txr-2 had not opened due to which the fault continued to be fed from the remote ends (Pondy-PG amp NLC-2)

It was noted that the HV (230 kV) side OC protection of Txr-2 which was supposed to act under above situation had NOT acted

Due to above the remote end back-up protections were called into action

It was noted that even though Pondy-PG end CB tripped on DPR Z3 protection the time delay observed was on the lower side of about 06 sec

It was also observed that DEF protection had acted to trip its CB at NLC-2 without giving any chance for its distance protection to operate

In view of the above observed inconsistencies at Villianur SS it was decided to review various feeder amp transformer protections kept at Villanur SS during its scheduled protection audit on 10072017

Subsequently protection audit of 230 110 kV Villianur SS of PED was conducted on 10072017 during which several lacunae were noted Accordingly a comprehensive set of recommendations were given to PED for early compliance

Recommendations

PED to furnish an action taken report wrt complying with the protection audit recommendations PGCIL (SR-II) to review Zone-3 and DEF protection setting at Pondicherry end 230 kV Pondicherry ndash

Villianur and 230 kV Pondicherry ndash Bahour line and set them appropriately to achieve required

Annexure-II

time-coordination with OC protections of ICTrsquos at Villianur SS NLCIL to keep DEF protection in blocked condition as long as Distance Protection is active and

configure it to become active only when distance protection does not pickup to avoid time-coordination issues

Complete outage of 400kV Uravakonda and Jammalamadugu Substations

31-05-2017 at 1744 hrs

Triggering incident was tripping of 400 kV Kurnool-PG - Narnoor line - 1 amp 2 and 400 kV Narnoor-Jamalamadugu line-2 which led to loss of supply to 400kV Uravakonda and Jamalamadugu 400kV Gooty-Narnoor 400kV Narnoor-Jamalamadugu-1 400kV Srisailam-Narnoor 400kV Uruvakonda-Mahboobnagar-1amp2 were out of service in antecedent condition

Gen Loss 500 MW

FNN not followed by APTRANSCO FIR amp TR in prescribed formats not furnished by APTRANSCO SLD

The single line diagram 400 kV Jammalamadugu SS as furnished by APTRANSCO are attached at the end

Annexure-II

Antecedent Conditions

The following lines were kept out of service 400kV Narnoor-Srisailam SC line 400kV Narnoor-Gooty SC line 400kV Narnoor-Hyderabad SC line 400kV Narnoor-Jamalamadugu-1 line 400kV Uravakonda-Jamalamadugu-1 line 400kV Uravakonda-Mahboobnagar line-1amp2

Above means Uravakonda SS and Jammalamadugu SS were effectively hanging on to 400 kV Jamalamadugu - Narnoor line-2 for supply

A Tripping of 400 kV Kurnool (PG) - Narnoor line-1 Kurnool-PG (PGCIL-SR1) end

As per FIRTR line tripped at 174418601 hrs due to DPR Z3 (5703 km) operation

As per DREL line tripped at 174418601 hrs due to Stub Protection operation Narnoor (APTRANSCO) end

As per FIRDREL line tripped at 173620637 hrs due to operation of Igt4 (B-ph) protection

From EL Igt4 time delay was observed as 100 msec

Time sync of protection relays with GPS needed to be ensured B Tripping of 400 kV Kurnool (PG) - Narnoor line-2 Kurnool-PG (PGCIL-SR1) end

From EL Igt4 time delay was observed to be about 100 msec

Time sync of protection relays with GPS needed to be ensured C Tripping of 400 kV Narnoor ndash Jammalamadugu line-2 Narnoor (APTRANSCO) end

As per FIRDREL line tripped at 174423979 hrs due to OVR-I operation (From EL OVR-I Time delay was observed as 5 sec which is in line with SRPC provided gradings)

Jammalamadugu (APTRANSCO) end

As per FIR line tripped at 1744 due to DT receipt from Narnoor end

As per DR line tripped at 174415040 hrs (Type of Protection operated was not recorded)

In EL events recording started from 174424037 hrs Line was observed to have got tripped around this time due to 862 operation (Type of Protection operated was not recorded)

Time sync of Protection relays with GPS needed to be ensured SRPC SRLDC

As informed by APTRANSCO it was noted that the triggering cause for operation of Stub protection Igt4 protection was a line fault on 400 kV Ghani ndash Narnoor line-1 Even though Ghani end had tripped on DPR Z1 protection and sent carrier to Narnoor due to unhealthiness of carrier communication (PLCC related issues) Narnoor end tripped on DPR Z2 protection

The above fault was seen by relays at both ends of 400 kV Narnoor ndash Kurnool-PG lines 1 amp 2 (the relays of P444 make are owned by PGCIL-SR1 and the relay settings were also provided by PGCIL-SR1)

As in formed by PGCIL (SR-I) it was noted that there was an instantaneous non-directional Igt4 protection setting in the specific relay style (defined by relay make model and version) which operates without checking for isolator status During the above instant the flow of heavy fault

Annexure-II

current led to its operation both ends

To this PGCIL (SR-I) was informed that by default Igt4 or stub protection is configured for instantaneous operation with corresponding isolator open position interlock So further instantaneous high-set functionality that operates without checking isolator positional status is not desirable since it can lead to unwarranted trippings as in the present case Therefore the said setting shall be kept disabled If there is no provision to effect this (by means of changing relay settings) the issue may be referred to its OEM for obtaining modified firmware suitable solution PGCIL (SR-I) can also make use of other relays with different style in place of the existing relays

Recommendations

For 400 kV Ghani ndashNarnoor line the following shall be carried out by APTRANSCO End-to-end communication for DT permissive amp other signals may be ensured by testing at

both the ends Healthiness of PLCC system components (hardware and software) at both ends shall be checked

and faulty components shall be repaired replaced PGCIL (SR-II) to take appropriate action wrt disabling non-directional instantaneous Igt4 protection

that operates without checking existence of stub If required the issue may be referred to relays OEM for appropriate solution or the present relays may be replaced with other relays with different styles that donrsquot have the issue observed

II Details of Grid Incidents

Sl No Details of Event Date amp Time Reason Category

1 Tripping of 220 kV Idukki ndashUdumalpet line

05-05-2017 at 1702 hrs

Line tripped due to B-N and R-N fault in line

Idukki (KSEB) end

As per FIRDREL line tripped (in 3-ph) at 170200500 hrs on B-E fault due to operation of DPR Z1 (3661 km) protection

Udumalpet (TANTRANSCO) end

As per FIRDRELTR line tripped (in B-ph) at 165741907 hrs on B-E fault due to DPR Z2 (CAT AR 1025 km) operation However during AR dead-time another R-E fault was detected at 165742252 hrs in Zone-2 due to which line tripped in 3-ph after Z2 time delay of 350 msec at 165742594 hrs [It may be noted that all this happened during the AR dead-time]

Time-sync of Protection Relays with GPS needed to be ensured at 220 kV Udumalpet SS KSEB

During the instant case line did not try for AR as the external VARM AR relay was faulty and kept out of service

Remedial action Problem with VARM relay had been rectified and put into service on 10052017

SRPC SRLDC

From the DR of Udumalpet it can be seen that the relay had tried for AR even after giving three phase trip during AR dead-time due to occurrence of two different faults which is not desirable

Annexure-II

Recommendations TANTANSCO to correctly configure AR logic at Udumalpet so that in the event of 3-ph trip being

given during AR dead-time the relay will not try for auto-reclosure TANTRANSCO to keep AR dead-time as 1 sec for all 220 kV amp above transmission lines

Tripping of 400 kV Kudgi (PG) - Tumkur line-2 and Kudgi (PG) ndash Kudgi (NTPC) line-1

06-05-2017 at 1605 hrs

Kudgi (NTPC) feeder tripped at Kudgi (PG) end on operation of distance protection R-N Zone-1 Tumkur feeder tripped at Kudgi(PG) end on operation of NGR buchholtz relay

The single line diagram of 765 400 kV Kudgi-PG SS as furnished by are attached at the end 400 kV Kudgi (PG) ndash Kudgi (NTPC) line-1 Kudgi (PGCIL-SR2) end

As per FIRDRELTR line tripped (in 3-ph) at 160547499 hrs on R-E fault due to DPR Z1 (M1 79 km 013 kA M2 88 km 318 kA) operation

Kudgi (NTPC) end

FIRDRELTR not furnished 400 kV Kudgi (PG) ndash Tumkur line-2 Kudgi (PGCIL-SR2) end

As per FIRDRELTR line tripped (in 3-ph) at 160547450 hrs due to operation of NGR Buccholtz trip protection

Tumkur (PGCIL-SR2) end

As per FIRELTR line tripped (in 3-ph) at 160547596 hrs due to DT receipt from Kudgi-PG end

In DR this time was mentioned as 160512593 hrs

Time-sync of protection relays with GPS needed to be ensured PGCIL (SR-II)

With regard to tripping of 400 kV Kudgi (PG) ndash Kudgi (NTPC) line ndash 1 and AR non-operation it was informed that prior to above fault there were multiple faults on all four lines between Kudgi (PG) and Kudgi (NTPC) due to prevailing stormy weather

Remedial action Actual reasons for AR failure in the instant case were being investigated The issue was also

referred to its OEM for suitable advice

With regard to tripping 400 kV Kudgi (PG) ndash Tumkur line ndash 2 it was suspected that NGR Buchholtz relay might have mal-functioned as there was no gas collected in the bucholtz relay of NGR It may be noted that NGR buchholtz trip is present in REF relay

Remedial action Oil sample of NGR taken and sent to RTDC

Recommendations PGCIL (SR-II) to sort out AR related issues at Kudgi (PG) end on 400 kV Kudgi (PG) ndash Kudgi (NTPC)

lines and put AR into service PGCIL (SR-II) investigate the reasons for NGR Buccholtz trip on 400 kV Kudgi (PG) ndash Tumkur line-2

and furnish an action taken report wrt rectifying the same

Annexure-II

3 Tripping of 220 kV Edamon-Tirunelveli lines - 1amp2

06-05-2017 at 1809 hrs

220kV Edamon-Tirunelveli - 1amp2 tripped from Tirunelveli end only and was in service from Edamon end

Edamon (KSEB) end

As per FIR line was kept holding from Edamon end Tirunelveli (PGCIL-SR2) end

As per FIRDRELTR lines tripped (in 3-ph) at 180921343 hrs on R-B fault due to DPR Z1 (532 km) operation

It was stated in TR that Edamon ndash Pothencode lines 1 amp 2 had tripped around the same time and it was suspected that DPRrsquos at Tirunelveli end on 220 kV Tirunelveli ndash Edamon lines 1 amp 2 might have over-reached for the fault in 220 kV Edamon - Pothencode lines

PGCIL (SR-II)

The instant case was a typical case of overreaching of distance relays at Tirunelveli being experienced for quite a while It may be probably due to bunching of the conductors involved

Remedial action It was proposed to modify Z1 setting as 50 of line impedance with POR and would be done

within one-week time They had also proposed to measure the actual line impedance of the line and adjust Z1 settings

accordingly

06-03-2017at 0607 hrs

4 Tripping of 400220 kV Ghani ICT-2amp3

07-05-2017 at 1405 hrs

ICTrsquos-2amp3 got tripped on operation of Y-phase over-current protection

FNN not followed by APTRANSCO FIRrsquos in prescribed format not furnished by APTRANSCO SLD

The single line diagrams of 400220 kV Ghani SS as furnished by APTRANSCO is attached at the end Tripping of 500 MVA 400 220 kV ICT-2

As per FIR ICT-2 tripped at 1405 hrs due to operation of Y-ph OC amp EF protections

DR amp EL not furnished Tripping of 500 mVA 400 220 kV ICT-3

DR amp EL not furnished SRPC SRLDC

When enquired about the reasons for operation of back-up protections of ICTrsquos ndash 2 amp 3 APTRANSCO replied that there was actually a fault on the 220 kV feeders emanating from 400 220 kV Ghani PS However since the CT Neutral connection setting had been wrongly set as ldquoTowards Bus siderdquo instead of the correct ldquoTowards Transformer siderdquo the back-up protections on 220 kV side operated for the said 220 kV line fault

APTRANSCO also informed that first ICT-2 tripped followed by ICT-3

But since it was not clear from the above explanation whether line protection on 220 kV side had operated or not and the delayed clearance of the fault observed during the incident (about 400 msec) APTRANSCO was asked to investigate the reasons for the same

APTRANSCO was also asked to check whether carrier aided protection is healthy on 220 kV lines emanating from 400 220 kV Ghani PS

07-03-2017 at 1602 hrs

Annexure-II

Recommendations APTRANSCO to check and correct all CT Neutral Connection settings in various protection relays at

their 400 220 kV Ghani PS APTRANSCO to ensure that PLCC carrier aided protection is maintained healthy on 220 kV lines

emanating from their 400 220 kV Ghani PS APTRANSCO to take steps to complete configuration works of DRrsquos amp ELrsquos of various protection

relays at their 400 220 kV Ghani SS and furnish the same as and when required in compliance of IEGC Regulation 52 (r)

5 Tripping of 400 kV Ghanapur-Mamidapalli line

08-05-2017 at 1915 hrs

Line tripped at Ghanapur end only and was holding from Mamidapalli Ghanapur end protection had sensed R-phase to earth fault

Mamidipalli (TSTRANSCO) end

As per FIR line was kept holding from Mamidipalli end

In DR R-E fault current (2894 kA) along with dip in R-ph voltage could be seen but if any protection relay had picked could not be verified Also EL furnished did not contain events for this time (In fact no events were found recorded after 160610859 hrs)

Ghanapur (PGCIL-SR1) end

As per FIRTR line tripped (in 3-ph) at 1915 hrs on R-E fault due to DPR Z1 (49 km 2547 kA) operation

As per DR line tripped (in 3-ph) at 191330020 hrs on R-E fault due to 3-ph Group-B Trip relay operation (Zone-3 pick-up also could be observed)

As per EL line tripped (in 3-ph) at 191541722 hrs on R-E fault due to 3-ph Group-B Protection Trip relay operation

Time-sync of protection relays with GPS needed to be ensured

When enquired about the reasons for observed discrepancies PGCIL (SR-I) informed that line tripped on operation of distance protection Since last 2-3 trippings permissive carrier was not being received at Mamidipally end

Further since PLCC at both ends belong to TSTRANSCO thorough check-up of PLCC carrier communication and tuning of PLCC link needed to be undertaken

For above one-day shut-down of line was requested to which SRLDC agreed

Recommendations For the line under consideration the following shall be carried out by TSTRANSCO in coordination

with PGCIL (SR-I) End-to-end communication for DT permissive amp other signals may be ensured by testing at

and faulty components shall be repaired replaced

08-03-2017 at 1033 hrs

6 Tripping of 400220kV ICT-1 at Guttur

09-05-2017 at 2215 hrs

ICT-1 tripped on HV side only without any relay indications GI-2

As per FIRTR ICT-1 tripped at 2215 hrs only on HV side without any relay indications KPTCL

ABB make RXMS trip relays provided in various lineICT panels were found to be mal-operating and the phenomenon observed was suspected due to raise in earth potential during any fault in Guttur substation

10-03-2017 at 1801 hrs

Annexure-II

Remedial action Action wass being taken to provide 10kΩ resistor in series with the RXMS relay coil for all trip

relays of this type at Guttur Total 170 nos of such resistors were required Now purchase formalities were finalised and work of supply and fixing of resistors would be taken up and completed within a monthrsquos time

7 Tripping of 400 kV Narsapur-Shankarapalli line

10-05-2017 at 0007 hrs

Line tripped at Narsapur end only on B-Phase to earth fault and line did not trip from Shankarapalli

Shankarapally (TSTRANSCO) end

As per FIR line was kept holding from Shankarapally end Narsapur (TSTRANSCO) end

As per FIRDREL line tripped in 3-ph at 000720105 hrs on B-E fault due 86 Trip relay (130 km) operation

The type of protection operated was not recorded shown in either DR or EL

TR not furnished TSTRANSCO

For the fault on 400 kV Shankarapalli-Mamidapalli line Narsapur end picked up in Z3 However due to configuration issues relating to programmable Zone Zp (this was being used as Zone-3 and its time-setting was found to be kept as zero sec) it tripped instantaneously instead of tripping after Zone3 time delay

Remedial action PSL Configuration for Zp was set right on 01-06-2017

13-03-2017 at 2347 hrs

Annexure-II

Tripping of 400220 kV Hyderabad ICT-4 and 220 kV lines at Hyderabad substation

10-05-2017 at 239 hrs

Operation of busbar protection due to fault in 220 kV Bus at 220kV Hyderabad Substation

1 2 1 2

BUS BAR ACTED AT 220KV GHANAPUR SS ON 10-05-2017

CHANDRAYANAGUTTA HAYATHNAGAR

132KV BUS

160MVA-3 100MVA-1

400kV PGCIL

160MVA-2ICT-1 ICT-2 ICT-3

NAGOLE

MOULALI

INFOSYS

Y-Ph disc

flash over at

LocNo95

Y amp B-Ph

disc flash

over at

LocNo95

RELAY INDICATIONS ON THE FEEDER

AT GHANAPUR END AT CHANDRAYANGUTTA END

Chandrayangutta-I feeder Ghanapur-I feeder

Main-1 relayYNZ1 071kM Main-1 relayYN254kM

Main-2 relayYNZ1 09kM Main-2 relayYN

Chandrayangutta-II feeder Ghanapur-II feeder

Main-1 relayYB Z1378kM Main-1 relayRYB

Main-2 relayYBZ111kM Main-2 relayRYB

14-03-2017 at 1911 hrs

Annexure-II

Tripping of ICT-4

As per FIR ICT-4 tripped at 0240 hrs on 220 kV side only due to BBP operation on 220 kV Bus

As per DR ICT-4 tripped at 220941165 hrs apparently due to LBB operation

EL not furnished

Date amp Time-sync of DR not in order (09052017 220940682 hrs)

TR furnished did not contain any analysis or remedial action taken

It was noted that BBP for 220 kV Bus-2 had operated for a close-in line fault on 220 kV Chandrayanagutta line-2 tripping ICT-4 and other connected 220 kV feeders (It was informed that ICT-2 was not in service at the time of instant tripping)

When enquired about the reasons TSTRANSCO informed that presence sudden appearance of current in the corresponding Peripheral Unit (PU-2) of the Chandrayanagutta line-2 had led to BBP operation And the reasons for the same were being investigated

To this it was suggested to check corresponding CT neutral connection integrity of cable wiring from CT to Busbar panel as also carry out stability-check of busbar protection

Recommendations TSTRANSCO to investigate the reasons for BBP operation for 220 kV Bus-2 and furnish a report on

the remedial measures taken

9 Tripping of 400220 kV ICT-1 at BTPS

13-05-2017 at 1941 hrs

ICT-1 got tripped on operation of LV side earth fault protection during R-phase to earth fault in 220 kV BTPS-Lingapur line

The single line diagram of 400220 kV BTPS as furnished by KPCL is attached at the end

As per FIRTR ICT-1 tripped at 1942 hrs on LV side earth fault protection due to fault in 220 kV BTPS ndash Lingapur line It was stated that the line also tripped around the same time on R-E fault due to DPR Z1 (2438 km) operation

DR amp EL pertaining to ICT-1 tripping not furnished

As per furnished DREL 220 kV BTPS ndash Lingapur line tripped from BTPS end at 194124719 hrs due to DT receipt from the remote end

ICT-1 tripped due to non-directional sensitive earth fault protection provided on LV (220 kV) side

Remedial action The time lever for above protection was increased from 0025 to 01 in the third week of May

2017 in consultation with KPTCL KPTCL

220kV BTPS- Lingapur line tripped at both the ends with following indications At BTPS Lingapur Line tripped on DPRZone-1RN24km78kA

At Lingapur BTPS line tripped on DPRZone-2RN66km29kA

It was reported that 315MVA ICT-1 tripped on LV side earth fault protection along with Lingapur line

Remedial action Existing settings of ICT back up protection is obtained from local RT wing of KPTCL for review

Revised settings communicated to KPCL for implementation

16- 03-2017 at 0118 hrs

Annexure-II

SRPC SRLDC

Since the ICT has been provided with normal back-up directional OC amp EF protections a separate non-directional sensitive earth fault protection is not desirable hence the need for the same may be reviewed Otherwise its time lever shall be suitably increased to a higher value (say 035) so as not to cause unwarranted trippings

Further tripping of 220 kV BTPS ndash Lingapura line from BTPS end on DT receipt was not in order

When enquired about the reasons for AR non-operation in the instant case for the above line KPCL replied that there were issues with PLCC carrier communication hence it was kept out of service

Recommendations KPCL to review the need for providing separate non-directional sensitive earth fault protection for

ICTrsquos at their BTPS station and take steps to disable the same For 220 kV BTPS ndashLingapura line KPCL to resolve issues relating to PLCC carrier communication and

put AR into service

10 Tripping of 765 kV Kurnool-Tiruvalam line-2

19-05-2017 at 2003 hrs

Failure of R-phase LA at Tiruvalam end REF operation and DT send were observed from EL of Kurnool station

Kurnool (PGCIL-SR1) end

As per FIRTR the line tripped in 3-ph at 200318272 on R-B-E fault due to DPR Z2 (CDistance = 912) operation

As per DR line tripped in 3-ph at 200318272 hrs on R-E fault (B-E fault did not appear to be strong) due to DPR Z2 (CAT) operation and 3-ph Group - A amp B Trip relay operation (In DR DT receipt event was observed around the same time)

In EL REF protection operation of PU-P141 operation and DT_SEND to the remote end was observed at 200318340 hrs

Tiruvalam (PGCIL-SR2) end

As per FIRDRELTR the line tripped in 3 ph at 200318269 on R-E fault due to DPR Z1 operation and DT receipt from the remote end

It was stated in TR that 707 RLA (Reactor LA) had fallen down due to heavy wind and caused R-E fault

When enquired about the reasons for REF protection operation and consequent sending of DT to the other end PGCIL (SR-I) informed that the fault was detected as R-B-E fault hence three-phase trip was given However even though Main-CB got opened with its three poles opening simultaneously Tie-CB got opened in R-ph immediately while the other two phase poles took a while to open This had caused Tie-CB LB operation Since this protection was implemented in REF relay trip was extended from the same along with sending of DT to the other end

To this it was pointed out that in the instant case only R-E fault was apparent and the current in B-ph was almost at the normal value hence the sensitivity of distance relay zone elements may be checked Further Tie-CB LBB operation points to sluggishness of the CB-poles hence the opening time of tie-CB may be checked and properly set

It was also noted that in the EL of Tiruvalam DT Send event was observed after tripping of the line on R-E fault PGCIL (SR-II) was asked to look into the reasons for the same and take suitable remedial action

16-03-2017 at 1023 hrs

Annexure-II

11 Tripping of 400220 kV ICT-2 at Kalpaka SS

20-05-2017 at 1502 hrs

ICT-2 tripped due to operation of Transformer Buchholtz relay

As per FIR ICT-2 tripped at 15053283 hrs due to its Buccholtz relay operation It was stated in FIR that heavy rain amp gale had been reported at the time of tripping

APTRANSCO

Just prior to above tripping event station transformer supply went off When the supply came back the two oil cooling pumps which were supposed to start one after another with a time gap of 15 sec had started simultaneously due to problem in the timer module Due to this there was a sudden flow of oil which shorted the contacts of the micro-switch that gives buchholtz trip

Remedial action The faulty timer module of oil cooling pump had been replaced

On this SRPC asked for the details of AC auxiliary supply about its redundancy details of DG-set and the mode of starting (manual or auto) To this APTRANSCO informed that redundancy for AC auxiliary supply is present and the lost supply during the instant case had been restored immediately

Recommendations

APTRANSCO to furnish AC auxiliary supply details including its redundancy DG set details and its mode of starting at their 400 220 kV Kalpaka SS Further corresponding AC auxiliary supply changeover scheme drawing shall also be furnished

16-03-2017 at 1132 hrs

12 Tripping of 400220 kV ICT-2 at KV Kota SS

23-05-2017 at 1021 hrs

ICT-2 got tripped due to mal-operation of transformer oil temperature indicator

As per FIR ICT-2 tripped at 1021 hrs on both HV and LV sides due to transformer oil temperature indicator mal-operation

As per EL ICT-2 tripped at 1019XXXXX192 hrs on due to operation of OTI protection

It was stated that DR had not been triggered for the event

EL was not configured to show SECONDS in time-stamp of the events (This had been brought to APTRANSCOrsquos attention in previous PCSC meetings also)

APTRANSCO

At KV Kota SS OTI got stuck While checking the same its position indicator got changed and mal-operated resulting in 3-ph trip

Remedial action Ms CGL had visited the substation and declared the relay faulty It was proposed to replace the faulty OTI on 10072017

APTRANSCO was asked to configure Event Loggers at their KV Kota SS properly so that SECONDS are also displayed in the time stamp of the events recorded

16-03-2017 at 1245 hrs

Annexure-II

Tripping of 220 kV Kaniampeta - Kadakola line (Load Loss at Kaniampeta = 36 MW)

23-05-2017 at 1350 hrs

EFR relay operated and B-ph pole discrepancy relay operated leading to tripping of Bus-Coupler CB

Kaniampeta (KSEB) end

As per FIR in Kaniyampetta 220 kV substation all transformers tripped (Load loss 36 MW) at 1339 hrs due to the tripping of 220 kV Kaniyampetta-Kadakola feeder (B phase) at Kadakola end Later 220 kV Kaniyampetta-Kadakola feeder was hand tripped at 1426 hrs from Kaniyampetta end

Kadakola (KPTCL) end

As per FIR line tripped at 1350 hrs due to EFR operation of Bus-Coupler CB and PDR operation

It was also stated that at the time of tripping Kaniampeta panel had been taken up for RampU work hence distance relay was not in service Kaniampeta CB was bypassed by keeping protection through 220 kV Bus-Coupler CB

DR amp EL not furnished KPTCL

At Kadakola during the instance protection to Kaniambetta line was provided through 220kV bus coupler breaker bay as Kadakola relay panel was taken out for M-2 retrofitting work under RampU

Bus coupler breaker tripping was suspected due to problem in the pole discrepancy relay and there was no fault in the line

Remedial action Problem with the PD relay of Bus coupler breaker was rectified on 24052017

16-03-2017 at 2026 hrs

14 Tripping of 400 220 kV ICT-1 at Somanahalli substation

24-05-2017 at 1724 hrs

ICT-1 at Somanahalli substation got tripped due to DC Earth fault

Somanahalli (PGCIL-SR2) end

As per FIRTR ICT-1 tripped (on HV side) at 172809 hrs on momentary DC Earth fault

As per DREL ICT-1 tripped (on HV side) at 172809812 hrs due to operation of Group AB trip relays In DR manual trigger signal becoming HIGH was observed at above instant

In EL time resolution for recording events was limited to seconds (events were not shown at msec level)

PGCIL (SR-II)

At Somanahally SS 3x167 MVA single phase units had been replaced by 1x500 MVA ICT Subsequently CSD works were taken up At the time of tripping event CSD wiring works were going on During the process positive DC supply got extended to 86A trip relay inadvertently

Remedial action DC earth fault had been removed

PGCIL (SR-II) was asked to configure Event Loggers at their Somanahalli SS properly so that time resolution for recording events was set u pto msec

16-03-2017 at 118 hrs

Annexure-II

15 Tripping of HVDC Gazuwaka Pole-1amp2

25-05-2017 at 0945 hrs

HVDC pole-1 got tripped due to operation of South filter inter zone protection and HVDC pole-2 got tripped due to operation of differential protection

Pole-1

27-03-2017 at 1016 hrs

Annexure-II

Pole-2

Tripping of HVDC Pole-1 (PGCIL-SR1)

As per FIRELTR Pole-1 tripped at 094513960 hrs due to operation of South Filter inter-zone protection [

It was stated that DR was not available Tripping of HVDC Pole-2 (PGCIL-SR1)

As per FIRDRELTR Pole-2 tripped at 094512906 hrs due to operation of WIN Differential protection

It was noted that no representative from Gajuwaka (HVDC amp HVAC) SS had come to attend the meeting to explain as to what caused the pole trippings

PGCIL (SR-I) representative informed that at the time of tripping RTV Coating works for switchyard equipment were going on In the process when CWC35 filterrsquos bus-side isolator was opened it feel down unexpectedly and resulted in inter-zone filter protection operation

Wrt HVDC Pole-2 tripping PGCIL (SR-I) representative informed that oscillations in voltage and current were noticed prior to tripping of HVDC Pole-2 And differential current was also observed for the extended AC bus Due to this WIN differential protection had operated resulting in tripping of HVDC Pole-2 It was also informed that the issue was referred to its OEM ABB (Sweden) for suitable advice

However since no detailed tripping report explaining the causes that led to tripping of HVDC poles and the remedial action taken had been furnished PGCIL (SR-I) was asked to submit the same

Recommendations PGCIL (SR-I) to furnish detailed report on the events that led to tripping of HVDC Poles ndash 1 amp 2

including remedial measures taken to PCSC forum Further the OEM report wrt tripping of HVDC Pole-2 shall also be furnished

Annexure-II

16 Tripping of 400 kV Kayathar-Karaikudi line

25-05-2017 at 1552 hrs

R-phase to earth fault had occurred in line There was Zone-2 3 phase trip operation at Kayathar end and Zone-1 3 phase trip at Karaikudi end

Kayathar (TANTRANSCO) end

As per FIRDRELTR line tripped in 3-ph at 155236989 hrs on R-E fault due to DPR Z2 operation (Z2 time delay observed was about 390 msec)

It was stated in TR that carrier channel was not healthy at the time of tripping and carrier signal was not received at this end during the fault

Remedial action Protection Coupler and OLTE were reset at both Karaikudi amp Kayathar ends and carrier channel

was made available Karaikudi (PGCIL-SR2) end

As per FIRDRELTR line tripped in 3-ph at 155236592 hrs on R-E fault due to DPR Z1 (186 km) operation

It was stated in TR that DPC had failed at the other end and resulted in Carrier Fail alarm at Karaikudi end issuing 3-ph trip

Recommendations

For the line under consideration the following shall be carried out by TANTRANSCO in coordination with PGCIL (SR-II) End-to-end communication for DT permissive amp other signals may be ensured by testing at

Tripping of 400220 kV ICT - 1 amp 3 at Hoody substation of KPTCL (Load Loss 750 MW)

26-05-2017 at 1230 hrs

R phase limb of ICT-1 bank pre-close supervision contact of trip coil -2 had arc over ICT-3 got tripped on over-loading

Tripping of ICT-1

As per FIR ICT-1 tripped at 1230 hrs due to arcing over of R phase limb of ICT-1 bankrsquos pre-close supervision contact of trip coil -2

As per DR the tripping took place at 114128806 hrs (Type of protection operated not recorded)

EL not furnished

Time sync of PRrsquos with GPS needed to be ensured

Remedial action The same was rectified and the circuit was changed by utilizing the spare auxiliary contact of CB

for R-ph limb by availing LC on 29052017 and charged the ICT-1 bank at 0432 hrs by getting the SRLDC code 1360

Tripping of ICT-3

As per FIR ICT-3 tripped at 1230 hrs due to operation of INV OC FWD protection amp 86A master trip relay

From the DR furnished (with trigger time = 114254202 hrs) tripping of ICT-3 and the type of protection operated were not clear

EL not furnished

Time sync of protection relays with GPS needed to be ensured at Hoody

Annexure-II

At Hoody 500 MVA ICT-1 tripped without any relay indication ICT-1 and 3 were in parallel each ICT carrying about 390MW of load Due to tripping of ICT-1 ICT-3 got over loaded and hence tripped on over current protection

Remedial action After detailed inspection it was observed that pre-close supervision contact of trip coil -2 arced

over in R phase limb of the 400kV side breaker Hence it was suspected that R-pole might have opened initially and remaining poles on PD operation

The problem was rectified and attended on 29052017 by availing shut down In order to avoid tripping of another ICT operating in parallel whenever one ICT trips on fault an

SPS is being finalized by KPTCL which is to be implemented at Hoody Any time each ICT at Hoody will be catering around 400MW of load Such huge load shedding by tripping 66kV loads of Hoody station is difficult to achieve Hence 220kV radial feeders may also have to be tripped to get desired load shedding

It was noted that frequent tripping of 400 2220 kV ICTrsquos at Hoody SS had been observed in the past few months And during their discussion in various PCSC meetings the following issues have come to the for urgent action by KPTCL Implementation of Special Protection Scheme (SPS) to take care of over-loading of the other ICT

when one out of two ICTrsquos operating in parallel trips Provision of Bus-bar protection to 220 kV buses Compliance of Third Party Protection Audit Recommendations Ensuring supply reliability to Metro-services Action plan on the proposed system strengthening measures in Bengaluru area in the context

of continued use of Split-Bus operation

Thus to ascertain the action taken by KPTCL wrt above issues a Protection System Analysis Group (PSAG-18) meeting was proposed to be conducted on 03082017

Recommendations KPTCL to furnish compliance report on the recommendations given in PSAG-18 meeting to PCSC

18 Tripping of 400 kV Simhadri - Kalpaka line-2

28-05-2017 at 503 hrs

Line tripped on mal-operation of Tee Differential Protection at Simhadri end and Direct Trip was received at Kalpaka

Kalpaka (APTRANSCO) end

As per FIR line tripped at 0503 hrs due to DT receipt from the remote end

DR amp RL amp TR not furnished Simhadri STPS (NTPC) end

As per FIRTR line tripped at 050350408 hrs due to operation T-differential protection which in turn was attributed to spurious pick-up during the fault at Vemagiri end

The following was stated in TR Kalpaka Line-1amp2 Tie bays were under PTW And R-Ph CT (16CTA R-Ph) was under erection Primary connection was over secondary

connection was pending The CT secondary wires used in T-Diff protection of Kalpaka Line-2 might be touching the earth and during fault at Vemagiri some stray voltage developed across CT secondary cores might have resulted into operation of T-Diff protection Trip values are 100mA in secondary

During the operation of T-diff protection there was no change in current magnitudes of Kalpaka Line-2 and hence the tripping could be considered as spurious one

Annexure-II

As per DR line tripped at 050350442 hrs But the type protection operated was not recorded in it

EL not furnished (In place of EL DRrsquos eventsrsquo summary was furnished)

19 Tripping of 400 kV Ramagundam - Gajwel line

29-05-2017 at 0007 hrs

Over Voltage Stage-1 had operated at Gajwel end Ramagundam end did not trip as Direct Trip was not received from Gajwel end

Ramagundam STPS (NTPC) end

As per FIR line was kept holding from Ramagundam end Gajwel (TSTRANSCO) end

As per FIR line tripped at 0007 hrs due to OVR-I operation

DR amp EL amp TR not furnished

The tripping was not in order as per the SRPC given OVR gradings as shown below

When enquired about the reasons for OVR-I operation TSTRANSCO informed that OVR functionality implemented in REL 521 had mal-operated

Remedial action The OVR functionality had been moved to an external Over Voltage relay

Recommendations

For the line under consideration the following shall be carried out by TSTRANSCO in coordination with NTPC-Ramagundam End-to-end communication for DT permissive amp other signals may be ensured by testing at

20 Tripping of 400 kV Gajwel-Ghanapur line

29-05-2017 at 0007 hrs

Line tripped on operation of over voltage protection at Gajwel and direct trip was received at Ghanapur DR and EL of Gajwel end were not furnished

As per FIRELTR line tripped at 000731885 hrs due to DT receipt from the remote end

As per DR line tripped at 000257163 hrs due to DT receipt from the remote end

Time-sync of DR amp EL with GPS needed to be ensured Gajwel (TSTRANSCO) end

Annexure-II

When enquired about the reasons for OVR-I operation TSTRANSCO informed that there was a loose

wiring in Y-ph CVT wiring which resulted in mal-operation of OVR-I protection

Remedial action All CVT wirings had been tightened for fool-proof operation

III Details of Trippings due to Failure or Non-operation of Auto-Reclose

Sl No Element Date amp Time Reason

Category

1 Tripping of 400 kV Hiryur-

BTPS line-1 06-05-2017 at 1401 hrs

Y-phase to earth fault had occurred in line Direct trip was sent from BTPS to Hiryur end

Hiryur (PGCIL-SR1) end

As per FIRDRELTR line tripped (in Y-ph) at 140009730 hrs on Y-E fault due to DPR Z1 (AR 82 km 1034 kA) operation Just prior to auto-reclosing DT was received at 140010730 hrs and line tripped in 3-ph

BTPS (KPCL) end

As per FIRTR line tripped (in Y-ph) at 1400 hrs on Y-E fault due to DPR Z1 (AR 1173 km) operation AR was stated to be attempted but unsuccessful due to persistent fault

As per DREL line tripped (in Y-ph) at 125520000 hrs on Y-E fault due to DPR Z2 (CAT AR) operation and tried to auto-reclose after about 1 sec but tripped in 3-ph due to persistent (Z1) fault

Time-sync of Protection Relayrsquos with GPS needed to be ensured at BTPS

When enquired about the reasons for sending of DT to Hiriyur end KPCL informed that when the line tripped on Y-E fault and the AR operation was in progress Under-Voltage relay at BTPS end had sensed under-voltage and sent DT to Hiriyur end

It was noted that instantaneous tripping of UV relay and consequent of sending of DT to the other end are undesirable It was therefore suggested to introduce suitable delay (say 3 sec) for UVR tripping and disable sending of DT to the other end

Recommendations

KPCL to introduce suitable delay (say 3 sec) for UVR tripping and disable sending of DT to the other end on UVR operation at their BTPS station

Annexure-II

2 Tripping of 400 kV Munirabad-Guttur line

06-05-2017 at 1702 hrs

R-phase to earth fault Auto-reclose was successful at Guttur and Breakers at Munirabad end got tripped

Munirabad (PGCIL-SR1) end

As per FIRDRELTR line tripped (in 3-ph) at 170231624 hrs on Y-E fault due to DPR Z2 (AR CAT 1145 km) operation

Guttur (KPTCL) end

As per FIR line tripped (in R-ph) at 1702 hrs on Y-E fault due to DPR Z1 (AR 4708 km Ir=6877 kA) operation and successfully auto-reclosed

As per DREL line tripped (in R-ph) at 165933499 hrs on Y-E fault due to DPR Z1 (AR) and successfully auto-reclosed after about 1 sec

Time-sync of Protection Relays with GPS needed to be ensured at Guttur SS

When enquired about the reasons for AR non-operation at Munirabad end PGCIL (SR-I) informed that the external VARM relay through which AR had been implemented had not operated Since the relay belonged to KPTCL suitable action needed to be taken by them

On this KPTCL was asked to look into the issue and replace the relay if required PGCIL (SR-I) was also requested to coordinate with KPTCL in attending to this matter

Tripping of 765kV Kurnool-NPS line -2

07-05-2017 at 1405 hrs

Y phase to earth fault had occurred in line Auto-reclose was successful at Kurnool end and AR was not attempted at NPS end

Kurnool-PG (PGIL-SR1) end

As per FIRELTR line tripped (in Y-ph) at 140543316 hrs on Y-E fault due to DPR Z1 (AR 328 km 166 kA) operation and successfully auto-reclosed after about 11 sec After about further 6 sec (ie at 140550470) line tripped in 3-ph due to receipt of DT from the remote end

It was stated in FIR that 765 kV Kurnool ndash NPS line-1 was under LVRD

As per DR line tripped (in 3-ph) at 140550470 hrs due to DT receipt from remote end

DR corresponding to successful AR operation not furnished NPS (PGIL-SR1) end

FIR amp TR furnished were that of Kurnool station

As per DREL line tripped (in 3-ph) at 140543351 hrs on Y-E fault due to AR (Z2 CAT) operation It was noted from EL that AR LOCKOUT had operated around the same time due to which line had not tried for AR

From EL it was further observed that DT was sent to the remote end at 020550419 hrs However the cause of DT send was not recorded in EL

DR pertaining to DT send was not furnished

If DT send was because of OVR-I protection operation then also tripping was not in order as it does not match with the settings provided

PGCIL (SR-I)

Non-operation of AR from NPS was due to wiring mistake made during installation of Controlled Switching Devices (CSD) for the line reactor on this line

Remedial action The wiring issues in CSD installation were rectified on 18052017

Annexure-II

Tripping of 400 kV Krishnapatnam-Chittoor line-1

07-05-2017 at 1441 hrs

R-phase to earth fault Main CB Auto-reclose was successful at Chittoor end and Tie CB got tripped Breakers tripped at Krishnapatnam end and did not attempt auto-reclose

FNN not followed by APTRANSCO and APGENCO SDSTPS (APGENCO) end

As per FIRDREL line tripped (in 3-ph) at 144113756 hrs on R-E fault due to DPR Z1 (628 km) operation It was observed from EL that the line was given 3-ph trip straight way without initiating AR

Chittoor (APTRANSCO) end

As per FIRDRELTR line tripped (in R-ph) at 144113759 hrs on R-E fault due to DPR Z1 (1147 km) operation and successfully auto-reclosed after about 1sec However it was observed that only Main-CB got auto-reclosed successfully whereas Tie-CB got tripped in 3-ph while attempting AR

Remedial action When enquired about the reasons for AR failure at SDSTPS end APGENCO representative

informed that as informed in last PCSC meeting AR configuration logic is scheduled to be reviewed by ABB in July 2017 when all issues pertaining to AR operation would be sorted out

When asked about the reasons for AR failure for Tie-CB at Chittoor end APTRANSCO informed that Tie-CB AR dead-time and PDR operational time were inadvertently kept equal As remedial action PDR operational time was increased to 25 sec

5 Tripping of 765 kV Raichur-Solapur line-2

07-05-2017 at 1918 hrs

Y-phase to earth fault Auto-reclose was successful at Solapur and breakers at Raichur end got tripped

Solapur (PGCIL-WR1) end

As per FIRTR line tripped (in Y-ph) at 1918 hrs on Y-E fault due to DPR Z1 (AR 66 km 572 kA) operation and successfully auto-reclosed

DR amp EL not furnished Raichur (PGCIL (SR-I) end

As per FIRDRELTR line tripped (in 3-ph) at 191836810 hrs on Y-E fault due to DPR Z1 (145 km) operation It was observed from DR that AR lock-out had operated that resulted in tripping of Main-CB and Tie-CB But while Main-CB got tripped immediately Tie-CB got tripped in Y-ph only And the other two phase poles got tripped due to PDR operation after about 21 sec at 191838910 hrs

EL time-stamp resolution was limited to SECONDS instead of millisec

Tie-CB OPEN digital signals were observed to have employed NEGATIVE LOGIC PGCIL (SR-I)

The observed discrepancies at Raichur end were due to the hardware error caused by hanging of Main-CBrsquos BCU

Remedial action The problem with Main-CBrsquos BCU had been resolved by restarting it

Recommendations

PGCIL (SR-I) to configure Event Loggerrsquos time-resolution up to millisec level in all protection relays at their 765 400 kV Raichur SS

Annexure-II

Tripping of 400 kV Neyveli TS2-Pugalur line

07-05-2017 at 1955 hrs

Y-phase to earth fault Neyveli TS2 end relay issued a 3-phase trip 220ms after issue of Y phase trip Direct Trip was sent to Pugalur end preventing auto-reclose

NLC TS2 (NLCIL) end

As per FIRDRELTR line tripped in 3-ph at 195526677 hrs due to DT receipt from the other end

It was stated in TR that even though respective zones had picked up on fault DT receipt at the same time resulted in tripping of the line in 3-ph

In DR 3-ph trip was found to be issued 220 msec after Y-ph trip was issued It was also noted that DT receipt signal remained high for a duration of about 220 msec

Time sync of Protection Relays with GPS needed to be ensured at NLC-TS2

Pugalur (PGCIL-SR2) end

As per FIRDRELTR line tripped (in Y-ph) at 195534241 hrs on Y-E fault due to DPR Z1 (AR) operation However line tripped in 3-ph during AR dead-time at 195534353 hrs due to DT receipt from Neyveli end

In view of DT receipt at both ends it was suggested to carry out PLCC end-to-end testing to ensure healthiness of carrier communication

Recommendations

For the line under consideration the following shall be carried out by NLCIL in coordination with PGCIL (SR-II) End-to-end communication for DT permissive amp other signals may be ensured by testing at both

the ends Healthiness of PLCC system components (hardware and software) at both ends shall be checked

7 Tripping of 400 kV NCTPS -SVChatram line-2

09-05-2017 at 1843 hrs

R-phase to earth fault Auto-reclose is not in service since Fibre optic cable link is not healthy

NCTPS (TANGEDCO) end

As per FIRDRELTR the line tripped in 3-ph at 184223424 hrs on R-E fault due to DPR Z1 (9159 km 29 kA) operation (Given the length of this line as 95 km it may be verified whether Z1 setting is correct)

It was stated in FIR that AR was kept out of service due to defective FO communication link

Remedial action Line patrol done by lines wing and declared No Visible fault FO link cut was rectified on 13052017 and AR scheme restored

S V Chatram (TANTRANSCO) end

As per FIRDRELTR the line tripped in 3-ph at 184357616 hrs on R-E fault due to operation of DPR Z1 (32 km) operation

Time sync of protection relays with GPS needed to be ensured at both NCTPS and SV Chatram stations

Annexure-II

8 Tripping of 400 kV Madurai-Kudankulam line

10-05-2017 at 1940hrs

B-E Fault Auto-reclose successful at Madurai and breakers tripped at Kudankulam

Madurai (PGCIL-SR2) end

As per FIRDRELTR line tripped (in B-ph) at 194040402 hrs on B-E fault due to DPR Z1 (AR 137 km 114 kA) operation and successfully auto-reclosed after about 11 sec

Kudankulam NPP (NPCIL) end

As per FIRTR line tripped (in 3-ph) at 192936910 hrs on B-E fault due to DPR Z2 (CAT 2071 km) operation

It was informed that AR had not been kept in service as per SRPC decision Hence the tripping was in order

9 Tripping of 220 kV Idukki-Udumalpet line

14-05-2017 at 1345 hrs

Y-phase to earth fault had occurred in line Auto-reclose was successful at Idukki and breakers at Udumalpet end tripped on pole discrepancy

Idukki (KSEB) end

As per DRTR line tripped (in Y-ph) at 134620509 hrs on Y-E fault due to DPR Z2 (CAT 83125 km) and successfully auto-reclosed after about 08 sec

EL not submitted (In its place DRrsquos events summary was furnished)

As per FIRTR line tripped in Y-ph at 1345 hrs on Y-N fault on DPR Z1 (2834 km) operation Subsequently tripped in 3-ph on PDR operation

As per DR line tripped in Y-ph at 134151100 hrs on Y-E fault due to DPR (AR) operation But as DRrsquos time scale was limited to 1 sec post triggering AR complete operation could not be verified

From EL line all poles dead was observed at 134152102 hrs Cause of line tripping as stated in FIRTR was not observed in EL

The following was stated in TR The fault resistance measured in the M1 relay (MicomP442) was high resulting in Z3 pickup It was

evident from the fault record that M2 relay (7SA522) had cleared the fault in Z1 by opening Y-ph pole However since AR was implemented in only M1 relay and M2 (Z1) operation had not initiated AR in M1 it resulted in opening of the other two phase poles on PDR operation

The cause of non-initiation of AR of M1 relay on external initiation was found to be logic configuration mistake in the Main 1 relay

Remedial action The AR logic configuration in the PSL of Main 1 relay had been corrected However a special relay

test would be conducted to verify AR operation during the next opportunity shutdown

Time sync of protection relays with GPS needed to be ensured at Idukki and Udumalpet

10 Tripping of 400 kV Vemagiri - Gazuwaka line

14-05-2017 at 1654 hrs

Y-phase to earth fault Auto-reclose was not successful due to persistent fault Vemagiri end had sent a Direct Trip after un-successful Auto-reclose AR attempt was observed in Gazuwaka end DR after 3 phase trip

Vemagiri (PGCIL-SR1) end

As per FIRDRELTR line tripped in (Y-ph) at 165411968 hrs on Y-E fault due to operation of DPR Z1 (AR 1512 km) operation It tried to auto-reclose after about 11 sec but tripped in 3-ph due to persistent fault

Annexure-II

It was noted that AR was attempted by Tie-CB only the Main-CB tripped in 3-ph at the beginning of AR initiation

Also Tie-CB AR dead-time was observed to be one second

Reasons 3-ph trip of Main-CB needed to be furnished Gazuwaka (PGCIL-SR1) end

As per FIRDRTR line tripped in Y-ph at 165330242 hrs on Y-E fault due to operation of DPR Z1 (AR 1677 km) operation But during AR dead-time it tripped in 3-ph after about 115 sec due to DT receipt from the remote end This resulted in 3-ph opening of both Main-CB and Tie-CB However after 125 sec Main-CB Y-ph limb tried for auto-reclosure and tripped due to persistent fault

As per EL line tripped in (Y-ph) at 165351597 hrs on Y-E fault due to operation of DPR Z1 (AR) operation But during AR dead-time it tripped in 3-ph at 165352620 hrs due to DT receipt from the remote end This resulted in 3-ph opening of both Main-CB and Tie-CB However at 165352687 hrs Main-CB Y-ph limb tried for auto-reclosure and tripped due to persistent fault

Reasons for AR attempt by Main-CB event after opening in 3-ph due to DT receipt needed to be explained

Time sync of DRrsquos amp ELrsquos with GPS needed to be ensured at Gajuwaka SS Recommendations

PGCIL (SR-I) to sort out issues relating to AR functionality operation for both Main-CB and Tie-CB at both Vemagiri and Gajuwaka substations

For the line under consideration the following shall be carried out by PGCIL (SR-I) End-to-end communication for DT permissive amp other signals may be ensured by testing at both

11 Tripping of 400 kV VTPS-Sattenapalli line-2

21-05-2017 at 1706 hrs

B-phase to earth fault Auto-reclose successful at Sattenapalli and breakers got tripped at VTPS end

Sattenapalli (APTRANSCO) end

As per FIRDRELTR line tripped (in Y-ph) at 170653038 hrs on B-E fault due to DPR Z1 operation and successfully auto-reclosed after about 1 sec

VTPS (APGENCO) end

As per FIRDRELTR line tripped in 3-ph at 170653133 hrs on B-E fault due to DEFR (33 kA) operation (DPR Z2 had picked up and Carrier was also received from the other end)

APGENCO

Before the LILOing of 400 kV VTPS-Srisailam DC line at Sattenapalli DEF protection had been provided from a separate REX521 relay Subsequently even though all protections at VTPS had been revised the above DEF protection implemented from the REX521 relay had been somehow left out and it only had extended 3-ph trip during the current instant

Remedial action The DEF functionality from the said REX521 had been disabled

Annexure-II

12 Tripping of 400 kV Srisailam-Dindi line-2

24-05-2017 at 1502 hrs

R-phase to earth fault Auto-reclose was successful at Dindi and Zone - 1 3-phase trip at Srisailam

Srisailam (TSGENCO) end

As per FIRDREL line tripped in 3-ph at 150253522 hrs on R-E fault due to DPR Z1 operation

TR contained no information Dindi (TSTRANSCO) end

As per FIRDRELTR line tripped (in R-ph) at 150253487 hrs on R-E fault due to DPR Z1 operation and successfully auto-reclosed after about 1 sec

Recommendations Since all 400 kV lines emanating from Srisailam LB are composite feeders APTRANSCO TSTRANSCO

can keep AR functionality disabled at respective remote end stations under their control

IV Details of Trippings due to PLCC mal-operation

Category

1 Tripping of 400 kV Kalpakka-Gazuwaka line-1amp2

18-05-2017 at 1108 hrs

Line tripped at Kalpakka end only on Direct Trip receive and was holding from Gazuwaka

Tripping of 400 kV Kalpaka ndash Gajuwaka line-1

Gazuwaka (PGCIL-SR-2) end

As per FIR line was kept holding from Gazuwaka end Kalpakka (APTRANSCO) end

As per FIREL line tripped at 110625955 hrs to DT receipt from Gazuwaka end

Gazuwaka (PGCIL-SR2) end

Remedial action taken by APTRANSCO subsequent PCSC-65 meeting as informed vide their internal communication dated 20072017

Annexure-II

2 Tripping of 400 kV Tumkur-Bidadi line-1 amp 2

30-05-2017 at 1139 hrs

Line tripped due to suspected PLCC mal-operation at Tumkur end and direct trip was received at Bidadi

Tripping of 400 kV Tumkur ndash Bidadi line-1 Tumkur (PGCIL-SR2)) end

As per FIRDRELTR line tripped in 3-ph at 113515534 along with DT SEND to the remote end

PLCC mal-operation was suspected to have caused above tripping Bidadi(PGCIL-SR2) end

As per FIRTR line tripped in 3-ph at 113515 hrs due to DT receipt from Tumkur end Tripping of 400 kV Tumkur ndash Bidadi line-2 Tumkur (PGCIL-SR2)) end

As per FIRTR line tripped in 3-ph at 113515 hrs due to DT receipt from Tumkur end PGCIL (SR-II)

Remedial action The above trippings were due to PLCC mal-operation which in turn was due to shifting of its

coaxial cable The related circuitry was subsequently rectified

Annexure-II

Single Line Diagram of 230 kV Villianur SS of PED [Ref I1]

Annexure-II

Single Line Diagram of 400 kV Jammalamadugu SS of APTRANSCO [Ref I2]

Annexure-II

Single Line Diagram of 400 kV Judgi-PG GIS SS of PGCIL (SR-II) [Ref II4]

Annexure-II

Single Line Diagram of 400 kV Ghani SS of APTRANSCO [Ref II4]

Annexure-II

Single Line Diagram of 400 kV BTPS of KPCL [Ref II9]

Annexure-II

Meeting No

Details of Event Date amp Time Reason PCSC Recommendations Utility responsible for

Implementation

Status of Recommendations

as on 25072017

Remarks

Pending Implementation of PCSC Recommendations (up to 65th Meeting)

Complete outage of 220kV Yerraguntla

substation and tripping of running Units

at Rayalaseema TPS

52I2 (GD) PendingMail received on 27-07-2016

1The drop out relays of reducer oil pumps time setting was increased for

all millsSo there will not be any trip under transient low voltage condition--

--Complied

2The recommendation regarding 2 sec time delay will be implemented

during unit shut down and will be intimated immediately after

implementation------Pending

APGENCO 1 APGENCO to check associated logic for lube oil pump for correct

operation under transient low voltage conditions at Rayalaseema TPS

Unit-1

2 APGENCO to keep appropriate time delay fault ride through

delay (typically 2 sec) in VFD speed sensor relay at all its generating

Units including Rayalaseema TPS Units

HV B-Ph Current transformer of 100MVA Power

Transformer -1 failed resulting into a bus fault on

220KV Bus-1 Unit-1 and Unit-5 at RYTPS tripped

during the fault at Yerraguntla substation

21-02-2016 at

1039 hrs

Andhra Pradesh

APGENCO to furnish a report on the remedial action implemented

wrt overreaching of Krishnapatnam end distance relays during the

tripping of 400 kV Nellore (PG) - NPS line-1

APGENCO Yet to be informed Pending57II9 Tripping of 400 kV Nellore (PG) - NPS

line-1 400 kV Krishnapatnam-Nellore

(AP) lines -1amp2 and 400kV NPS -

MEPL line

18-07-2016 at

1905 hrs

Triggering incident was snapping of Y phase

conductor in 400kV Nellore (PG) - NPS line-1

Distance relay at Krishnapatnam end over-reached in

Zone-1 and resulted in tripping of 400kV

Krishnapatnam ndash Nellore (AP) lines - 1amp2 from

Krishnapatnam end Distance relay at MEPL over-

reached and resulted in tripping of MEPL-NPS line

from MEPL end

Yet to be informed Pending

APTRANSCO mail dated on 31-08-2016

To avoid the unwanted malopeartions due to the external LBB trip

initiation from PGCIL Vide letter Dt 04-08-2016 APTRANSCO has

requsted the PGCIL to arrange the Master trip relay and breaker contacts

of ICT-1 amp2 LV side to enable the internal LBB feature in the Busbar

protection scheme at 220kV Gooty Switching station Waiting for the

PGCIL response

To avoid the unwanted maloperations due to the external LBB trip

initiation from PGCIL vide letter Dt 04-08-2016 ARTRANSCO has

requested the PGCIL to arrange the Master trip relay and breaker contacts

of ICT-1amp2 LV side to enable the internal LBB feature in the Busbar

PGCIL response

Waiting for the PGCIL response

APTRANSCO mail dated 04032017 amp 24052017

SRPC is requested to coordinate with PGCIL in takind necessary action

Pending

Tripping of 400kV Krishnapatnam-

Nellore line-1

Line tripped on B-phase to earth fault and auto-

reclose was successful at Nellore(AP) end and un-

successful at Krishnapatnam end

APGENCO

56II13 Tripping at 220kV Gooty Substation of

APTRANSCO

24-06-2016 at

1604 hrs

LBB protection got operated for 400220kV ICT-2

breaker which had resulted in tripping of 220kV Bus-

2 at 220kV Gooty Substation

1 APGENCO SDSTPS to correct logic and ensure healthiness of ARscheme employed for transmission lines emanating from SDSTPSand furnish an action taken report to PCSC forum

2 APGENCO SDSTPS to configure DRrsquos of line protection relaysfor a post triggering period of 2 sec to capture complete ARoperation at their SDSTPS

Yet to be informed Pending63III1 28-02-2017 at

0516 hrs

1 APGENCO SDSTPS to correct logic and ensure healthiness of AR

scheme employed for transmission lines emanating from SDSTPS

and furnish an action taken report to PCSC forum

2 APGENCO SDSTPS to configure DRrsquos of line protection relays

for a post triggering period of 2 sec to capture complete AR

operation at their SDSTPS

Tripping of 400kV Krishnapatnam-Nellore line-2

R-phase to earth fault had occurred in line Auto reclose was successful at Nellore however protection at Krishnapatnam end issued a 3 phase

APGENCO63III3 02-03-2017 at 455 hrs

1APTRANSCO to check the healthiness of the connecting cable

between Gooty (PGCIL) and Gooty (APTRANSCO) and replace it

if required

2APTRANSCO to ensure that the distributed architecture employed

in implementing busbar protection at their Gooty 220 kV SS does not

introduce any unwarranted delays in transmitting the triggering signals

to the Central Unit

APTRANSCO

Annexure-III

63II2 Tripping of 400 kV KV Kota-Suryapet

01-03-2017 at

2005 hrs

Line tripped on operation of over-voltage protection

at KV Kota and Direct Trip was received at Suryapet

1 APTRANSCO to furnish (i) FIR amp TR for tripping events as

per SRLDC provided formats and (ii) DR amp EL within 24-hrs of

occurrence of tripping event in line with IEGC Regulation 52

2 APTRANSCO to adopt new OVR gradings for KV Kota

feeders and confirm the same

APTRANSCO Status vide APTRANSCO mail dated on 28-06-2017

1 FIR furnished amp DR configured

Pending

63II16 Multiple Trippings at 220kV Vizag

Switching Station (VSS) of APTRANSCO

27-03-2017 at

1016 hrs

Bus-2 bus bar protection operated at 220kV VSS

end resulting in the tripping of all the elements

connected to bus-2

1 APTRANSCO to furnish a detailed report on the reasons for LBB

BBP operation at 220 kV VSS for a fault on 220 kV Gangavaram

feeder and remedial action taken to prevent recurrence of such

events

APTRANSCO Yet to be informed Pending

64II1 Tripping of 400220KV 315MVA ICT-

1and 230kV elements at 400kV Vemagiri

substation of APTRANSCO

09-04-2017

at 1231 hrs

Suspected mal-operation of Busbar protection had

caused tripping of 220kV Bus-1 at Vemagiri

APTRANSCO to furnish a report on the remedial action taken along

with single line diagram of 400220 kV Vemagiri SS indicating fault

location and CBs involved and protections operated

64II2 Tripping of 400220 kV ICTrsquos ndash 2 amp 3 at

400 kV Ghani substation of APTRANSCO

10-04-2017

at 1729 hrs

ICTrsquos ndash 2 amp 3 got tripped due to operation of 220 kV

Bus-2 busbar protection at 400220KV Ghani

substation

APTRANSCO to furnish single line diagram of 400 220 kV Ghani SS

clearly indicating (i) bus-configuration (ii) location of fault (iii)

breakers involved and type of protections operated

Single line diagram sent vide mail dated 27062017

Pending

64III1 Tripping of 400 kV Uravakonda-

Jammalamadugu line-1

02-04-2017 at

1758 hrs

R-phase to earth fault and line did not auto-reclose

Fault clearing time - 500ms

For the line under consideration APTRANSCO to check amp ensure

healthiness of carrier protection and make Auto-Reclosure

functional

Carrier aided protection scheme has been tested end to end and rectified

the problem

Pending

64III5 Tripping of 400kV Krishnapatnam-

Nellore line-2

11-04-2017 at

241 hrs

Line tripped on Y-phase earth fault Line auto-

reclosed at Krishnapatnam and did not auto-reclose

at Nellore-AP (Manubolu)

For the line under consideration APTRANSCO to look into reasons

for AR failure at Nellore-AP (Manubolu) end and furnish a report

on the remedial action taken

The ABB make REL 670 type main-2 distance relay seen the fault as R-

Y phase to phase fault Hence AR is not operated For the similar incident

on 07062017 the operation of AR is successful

Pending

Nellore line-1

12-04-2017 at

251 hrs

Pending

64III10 Tripping of 400kV Krishnapatnam ndash

Nellore_AP line-1

13-04-2017 at

438hrs

Y-phase to earth fault Line auto-reclosed from

Krishnapatnam end and did not auto-reclose fromNellore-AP end

for AR failure at Nellore-AP (Manubolu) end and furnish a reporton the remedial action taken

Pending

64IV4 Tripping of 400 kV VTPS-Malkaram line 20-04-2017 at

1624 hrs

Line tripped on Direct Trip Receive at Malkaram and

was in service from VTPS

For the line under consideration APTRANSCO to check the

healthiness of protection couplers and take suitable remedial action including replacement of the same

65II10 Tripping of 400220 kV ICT-2 at Kalpaka

20-05-2017 at

1502 hrs

ICT-2 tripped due to operation of Transformer

Buchholtz relay

APTRANSCO to furnish details of AC auxiliary supply details

including its redundancy DG set details and its mode of

starting AC auxiliary supply changeover scheme drawing shall

also be furnished

1 APTRANSCO to check and correct all CT Neutral

Connection settings in various protection relays at their 400

220 kV Ghani PS

2 APTRANSCO to ensure that PLCC carrier aided protection

is maintained healthy on 220 kV lines emanating from their

400 220 kV Ghani PS

3 APTRANSCO to take steps to complete configuration works

of DR‟s amp EL‟s of various protection relays at their 400 220

kV Ghani SS and furnish the same as and when required in

compliance of IEGC Regulation 52 (r)

07-05-2017Tripping of 400220 kV Ghani ICT-2amp3 65II4 APTRANSCO Yet to be informed Pending

PGCIL response

Pending56II13 Tripping at 220kV Gooty Substation of

APTRANSCO

24-06-2016 at

1604 hrs

63III2 02-03-2017 at

157 hrs

1 APTRANSCO to check and ensure correctness of AR operation

for the lines emanating from their Nellore-AP (Manubolu) SS

2 APTRANSCO to configure DR‟s of line protection relays for a

post triggering period of 2 sec to capture complete AR operation at

their Nellore-AP (Manubolu) SS

1The ABB make REL 670 type main-2 distance relay seen the fault as Y-

B phase to phase fault Hence AR is not operated For the similar incident

Pending

if required

to the Central Unit

APTRANSCO

Nellore line-1

Line tripped on B-phase to earth fault and line auto-

reclosed from Krishnapatnam end but did not auto-

reclose from Nellore-AP end

Annexure-III

64II16 Tripping of 400 kV VTPS-Satenapalli line-

30-Apr-17 at

428 hrs

Line tripped on B-phase to earth fault FIR DR and

EL of both ends were not furnished to validate the

tripping

APGENCO and APTRANSCO to furnish a detailed report on the

events leading to tripping of the line along with remedial measures

taken to PCSC forum

APGENCO

APTRANSCO

65II8 Tripping of 400220 kV Hyderabad ICT-

4 and 220 kV lines at Hyderabad

substation

10-05-2017 at

239 hrs

Operation of busbar protection due to fault in 220 kV

Bus at 220kV Hyderabad Substation

TSTRANSCO to investigate the reasons for BBP operation for 220

kV Bus-2 and furnish a report on the remedial measures taken

TSTRANSCO Yet to be informed Pending

24-12-2016 at

1052 hrs

Line tripped on B-phase to earth fault First fault was

persistent for 380 ms Auto-reclose was successful at

Khammam end during 1st fault 2nd fault occurred

during re-claim time of breaker hence Khammam end

breakers also got tripped

1 TSGENCO to implement the SRPC agreed philosophy for Power

Swing Blocking in all distance relays on the feeders emanating from

2 For the line under consideration TSGENCO to consult relays

OEM to migrate to new versions of Firmware (from to 47201) and

Pset (to 47002)

61III5 Tripping of 400 kV Khammam - KTPS

line-2

The issue was discussed in PCSC-58 meeting held on 18102016 when

PCSC forum agreed to de-link the implementation of the Item from the

scope of Protection Audit Recommendations (PAR) and pursue it as part

of PCSC Recommendations

TSGENCO mail dated 30-05-2017

Procurement of Differential Protection relays is under process and the

work will be completed by the end of November 2017

TSGENCOProvision of line differential protection for Jurala line 1 amp 2 (line length-145 KM) feeders at 220 kV Jurala HPS [Carry-Over from Protection Audit Recommendations]58 Pending

Pendingline tripped on direct trip receive at Gajwel and was

holding from Hyderabad

Pending

06-10-2016 at

1216 hrs

For the line under consideration TSTRANSCO to carry out the

following in coordination with TSGENCO

(i) Healthiness of PLCC system components (hardware and software)

at both ends shall be checked and faulty components shall be repaired

replaced

(ii) End-to-end communication for DT permissive amp other signals

may be ensured by testing at both the ends

(iii) Frequency bandwidth tuning of PLCC link for faithful

transmission of signals shall be carried out

62IV5 Tripping of 400 kV Gajwel-

Bhoopalapalli line-1

Telangana

TSGENCO TSGENCO mail dated 30032017

1 According to SRPC phylosphy power swing block settings are changed

to ALL ZONES BLOCK EXCEPT ZONE1

---------- Completed

2 Ms Siemens is requested to depute the service Engineer to update the

firm ware of existing SIPROTEC relays in 400KV switch yard This work

will be completed on or before 15042017 -------------- Pending

Pending

TSGENCO

TSTRANSCO

TSTRANSCO mail dated on 31-05-2017

1 Letter is been given to field for conducting end to end testing of 400kV

Gajwel-Bhoopalpalli-1 line

Line tripped at Bhoopalapally on DT receive and was

holding from Gajwel

(i) Letter is been given to field for conducting end to end testing of 400kV

Gajwel-Ghanapur line

(ii) Healthiness of PLCC system components will be checked while

conducting end to end testing

TSTRANSCO

16-02-2017

at 1500 hrs

For the line under consideration the following shall be carried out by

TSTRANSCO in coordination with PGCIL (SR-I)

(i) End-to-end communication for DT permissive amp other signals

(ii) Healthiness of PLCC system components (hardware and software)

replaced

Tripping of 400 kV Gaiwel-Hyderabad

Annexure-III

Karnataka

Annexure-III

38GD35 Pending13-11-2014 at

1931hrs

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

help of KPTCL at the earliest

2 KPCL to investigate the reason for DC fuse fail during

transient fault in 220kV Kadra-Kodasalli line including the testing

checking of DC supply cables breaker control cables and trip coils

3 KPCL to ensure supply for Main-1amp Main-2 protections Trip

Coils (TC1 TC2) from separate battery banks

Triggering incident was B-phase to earth fault had

occurred in 220kV Kadra-Kodasalli line Line tripped

from Kodasalli end only 220kV Kaiga-Kadra tripped

in Zone-3 from Kaiga end Tripping of evacuating

lines caused bus shut down at Kadra hydro station

16-02-2015 at

1256 hrs

GD-1 at Kadra and Kodasalli hydro

power station

GD-1 at 220kV Kadra power Station of

41I1 Mail received on 28-05-2015

1 Main-2 relays already installed and commissioned

2 DC fuses are intact Till date no such incidence occurred

3 Possibility of DC-1 amp DC-2 arrangement and splitting of DC will be

reviewed

Mail received on 07-07-2015 21-10-2015 and 23-11-2015

1 Completed

2 Completed

reviewed

Status received vide KPCL mail dated 14062017

1 Completed

2 Completed

3 Providing 2 separate DC sources is under process

Pending

Mail recieved on 28-05-2015

1) e-NIT floated on 28072014 for procurement of Numerical distance

relays amp GPS As there is change in scope of work and quantity of relays

by more than 25 which is not permitted as per KTPP act Hence tender

cancelled and refloated on 05052015 with revised scope of work and

revised PQR

2 However as per the recommendations of PSAG Relays were

temporarily rearranged replaced and wired up testing amp commissioning

shall be completed with the assistance of KPTCL

1 Cover -1 of the bid is scheduled for open eing on 25062015

2 As per the recommendations of PSAG Relays were temporarily

rearranged testing amp commissioning completed with the assistance of

NIT floated on 5515 through e-portal Bid evaluation completed

Obtaining of Administration approval to place PO is in progress

However as per therecommendationsof PSAG-10 Relays

weretemporarilyrearrangedTesting amp commissioning completed with the

assistanceofKPTCL

NIT floated on 5515 through e-portal Bid evaluation completed LOAs

issued to Ms Schneider Electric Infrastructure Ltd on 08102015

LOAs issued to Ms Schneider Electric Infrastructure Ltd on 08102015

Engineering work is in progress

Status informed during Special Meeting held on 03062016

LOA‟s issued to Ms Schneider on 08102015 Inspection of relays

completed and received at site DI issued for all balance materials except

furnitures

Numerical Distance Protection relays commissioned on 12042017

for all 4 lines at Kadra PH

Installation Testing and commissioning of Numerical Distance Protection

Relays for all the 4 outgoing lines is completed in all respect at Kodasalli

power house

KPCL1 The PCSC forum requested KPCL to speed up the installation of

Numerical Distance Protection relay in Kadra ndashKaiga and

Kodasalli ndashKaiga

2 The PCSC forum requested KPCL to submit the implementation

status of PSAG-10 recommendations within a week‟s time

A fault had occurred in 220 kV Kadra and Kodasalli

As A result de-energization of 220kV bus occurred at

Kadra and Kodasalli

Annexure-III

49II15

54II4 Tripping of 400 kV Raichur TPS-

Mahboobnagar line

05-04-2016 at

1023 hrs

Line tripped on operation of Backup impedance

protection of line reactor Direct trip was received at

Mahboobnagar end

KPCL to keep the functioning of the concerned electro-mechanical

back-up impedance protection relay under observation and replace it

with a spare at the earliest

KPCL Status received vide KPCL mail dated 10072017

The electro-mechanical back-up impedance protection relay is in service

However Budgetary offer obtained for the retrofitting of Line reactor

protection with Numerical relay and is under process

Pending

PendingStatus informed during Special Meeting held on 03062016

1 Hot line washing was done previouslytender process is on for silicon

coating of insulators

Status received vide mail dated 10-07-2017

1 Off line water washing is being carried out whenever the Unit or Line is

under shutdown Silicon coating for Unit8 main amp tie breakers carried

out in Sep16 and same is under observation Till today in order and good

condition For remaining breakers since it is big order approval for the

same is under process

2 Static Electromechanical relays are existing in all 1 to 7 units Breaker

flash over protection feature will be enabled (if available) in the numerical

relays which will be retrofitted in phased manner during RampM works

KPCL1 KPCL to carry out hot-line washing of RTPS-connected lines

regularly to avoid trippings due to fog and dust

2 KPCL may see the feasibility of providing breaker flashover

protection at RTPS and implement the same if possible

Running Unit-4 5 and Unit-8 and 400kV RTPS-

Yeramaras TPS feeder got tripped due to de-

energization of both 400kV Bus-1amp2 at Raichur TPS

12-11-2015 at

0030 hrs

54I4 220 kV Nagjheri - Bidnal line tripped on B-E fault at

1228 Hrs At the same time five running generating

units (1 2 3 4 amp 6) at Nagjheri tripped on operation

of Generator Transformer‟s back-up Over Current amp

Earth Fault protection

PendingKPCL

1 KPCL to revise the settings of GT‟s back-up OC and EF

protections considering their individual contribution to solid bus fault

at 220 kV bus of Nagjheri PH

2 KPCL to upload make available various tripping files

(FIRDRELTR) for all tripping involving their stations in compliance

of IEGC Regulation 52 (r)

14-04-2016 at

1229 hrs

Tripping of Nagjheri Generators Pending

Trippings at 220kV Raichur TPS

13-04-2016 at

2112 hrs

1KPCL to undertake the following remedial measures to avoid

breaker flashovers

(i) Replacing all porcelain insulators with composite insulators

(ii) Carrying out hot-line water washing of all insulators on regular

(iii) Applying Room Temperature Vulcanizing (RTV) Silicone high

voltage insulator coatings to all bus-connected ceramic insulators of

equipment like CT PT CB Isolators etc

2KPCL to take steps to provide dedicated breaker flashover

protection to all breakers at Raichur TPS at the earliest

Tripping of 400kV Raichur TPS Bus-2

46II21

Trippings at Raichur TPS

1 i) Silicon coating for Unit8 main amp tie breakers carried out in Sep16

and same is under observation Till today in order and good condition For

remaining breakers since it is big order approval for the same is under

process ii) Hot line

water washing stopped and off line water washing is carried out whenever

the 400 KV Unit or line is under tripped condition Shutdown condition

1 GT backup overcurrent amp earth fault settings are revised as per the

recommendations of our head office CEEDBangalore copy of letter

enclosed

2 FIRDRELTR are being uploaded in the recent incidences as all the

main-2 relays are replaced with new numerical relays

Mail received on 21-10-2015

1) Anti-pumping contactors of all the nine 220KV Lines are in circuit and

tested periodically during AOH works of lines along with other protections

2) Completed

3) Possibility to use both the 220kV buses as main bus under normal

operation is under review

1) Completed

3) Two bus operation for 220kV buses In place of existing CT switching

relays High speed manual heavy duty change over switch of sufficient

current capacity will be retrofitted to all feeders at 220kV station and same

will be operated manually during changeover of feeder by one bus to the

other and this arrangement may facilitate to put both buses in service Time

required for this retrofit is around 90days However this work will be

taken up only after retrofitting of electromagnetic relays with numerical

relays for Main-2 protection of all 220kV lines for which work is in

progress

1) Completed

2) Completed

3) Two Bus operation for 220kV bus is being carried out whenever

required However scheme for tripping of one bus during LBBfault and

maintaining the other bus intact by tripping BC breaker will be taken up in

RampM works

KPCL1 KPCL to check the operation of anti-pumping relay on 220 kV side

and keep it in healthy condition

2 KPCL to provide manual reset to the 220 kV side master trip relay

3 KPCL to use both the 220 kV buses as main buses under normal

operation and should go for single bus operation only during

emergencies

07-06-2015 at

0135 hrs

Y-ph Pole of Tie-breaker of Unit-4 at RTPS failed

Unit-4 got tripped on operation of Generator

Differential Reverse power amp LBB protection

Operation of LBB protection led to tripping of BUS-2

at RTPS

Annexure-III

56I2 Complete outage of 220kV Sedam

Substation of KPTCL

19-06-2016 at

1527hrs

220kV Sedam-Humnabad-2 tripped at Sedam on

Distance protection Zone-2 Sedam-RTPS-1 amp2 lines

tripped at RTPS end only 220kV Tandoor inter-state

line was hand tripped due to incoming supply failure

KPCL to disable GFC protection on all lines emanating from their

generating stations

As per the reccomndations of KPTCL in Feb16 the settings are done with

a time delay of 2 secs

Pending

57II3 Tripping of 400220 kV ICT-2 at Raichur

07-07-2016 at

332 hrs

ICT-2 tripped on operation 400220KV ICT-2 was

tripped on operation of 220KV side Instantaneous

over current protection during B-phase to earth fault

in 220kV RTPS-Sedam-II line

KPCL to review appropriately the high-set of ICT‟s back-up OC

protection at their 220 kV RTPS so that they do not operate for a

normal through fault

The settings will be reviewed in co-ordination with KPTCL amp OEM

Pending

1 All logics checked and found normal LBB timing checked and found

200msec as per KPTCL MRT recommendation - Completed

2 Work Under Progress

3 New GPS System commissioned along with new numerical and

synchronised with GPS system - Complied

1 DEF settings in lines are made as per recommendations of CE(RT) amp

RampD KPTCL Bangalore amp EE(RT) KPTCL Hubli

High set operation of DEF relays is disabled at Kodasalli end

2 All these guidelines are incorporated by KPTCL during the replacement

of line protection relays

3 New stand alone event logger is to be procured since spares for old

stand alone event logger are obsolete

KPCL (i) KPCL to disable high-set operation of DEF relays

(ii) KPCL to block DEF relays whenever corresponding distance

protection relays pick up at Kodasally end on Nagjheri ndash Kodasalli

lines and

(iii)KPCL to provide stand-alone Event Logger at their 220 kV

Nagjheri PH

Bus dead occurred at 220kV Nagjheri PH due to

tripping of evacuating lines

31-08-2016 at

1247hrs

Pending

Tripping of 400kV Bellary TPS-

Yeramarus TPS line and

400kVYeramarus TPS - Raichur TPS

PendingYet to be informed55II19

Tripping of Units at Raichur TPS During testing of retrofitted distance protection in

400kV Raichur-2 feeder LBB protection trip DC got

extended to Bus trip This resulted in tripping of

220kV bus at RTPS and all connected 220 kV

elements Unit-4 which is connected to 400 kV Bus

got tripped due to tripping of Station Utility

Transformer that is connected 220 kV bus

58I2 (GD)

Complete outage of 220 kV Kadra power

station of KPCL

54II13

1KPCL to properly configure the distance relays at YTPS end on

both YTPS ndash BTPS line and YTPS-RTPS line with specific focus on

reaches and timings of Zone-2 Zone-3 and Zone-4 (reverse)

2KPCL to ensure the healthiness of Direct Trip circuits and relay

coils at YTPS

3KPCL to ensure time sync of DR‟s and EL‟s at YTPS with GPS

06-09-2016

at 1440 hrs

31-05-2016 at

1721 hrs

Direct Trip was sent from YTPS to RTPS and BTPS

01-05-2016 at

2144 Hrs

LBB of 220kV Kodasalli breaker at Kadra end got

operated which resulted in tripping of Bus at Kadra

and in turn led to tripping of all elements

(i) KPCL to check settings of LBB protection in all relays from which

it was implemented and ensure that their configuration logic and

timing are in order at their 220 kV Kadra PH

(ii) KPCL to furnish details regarding the existing LT auxiliary

supply arrangement at their 220 kV Kadra PH and take steps to

provide a suitable Auto-Main-Fail (AMF) panel for DG set to effect

its auto-starting in case of failure of LT supply

(iii) KPCL to ensure time-sync of all relays (DR‟s amp EL‟s) with GPS

at their 220 kV Kadra PH

(iv) KPCL to provide stand-alone Event Logger at their 220 kV

Nagjheri PH

Complete outage of 220 kV Nagjheri PH

of KPCL

Multiple tripping at 400 kV Raichur TPS

Station

15-04-2016 at

1536 hrs

Triggering incident was failure of R-phase CT of

400220kV ICT-1 400kV YTPS-RTPS line got

tripped from YTPS end 400kV RTPS-

Mehaboobnagar line tripped on a B-phase to earth

In view of the availability of two buses along with healthy bus-

coupler at 220 kV RTPS KPCL is recommended to put in service the

double-bus operation at 220 kV RTPS by suitably distributing loads

within 15 days

Two Bus operation for 220kV bus is being carried out whenever required

However scheme for tripping of one bus during LBBfault and maintaining

the other bus intact by tripping BC breaker will be taken up in RampM

1KPCL to enable zero-sequence compensation feature if not already

done in all differential relays of transformers at RTPS

2KPCL to examine in detail the reasons for SOTF operation at RTPS

end for the fault on RTPS-Veltoor line and if required relay

(configuration) settings at RTPS end may be suitably got revised with

the help of their OEM

3KPCL to take steps to enable auto-reclose for the Tie-CB‟s in the

dias containing Munirabad and Veltoor (Mehboobnagar) at RTPS

1) Zero-sequence compensation feature is already enabled in all the

differential relays of transformers ---Completed

2) Referred to OEM for the tripping of line on SOTF protection

3) Action has been taken to retrofit the protection relays of tie bays of

Mahbubnagar and Munirabad line to enable Auto-reclosure function

58I3 (GD)

Pending

Annexure-III

1 On 09092016 at STRPTwo units were running(Unit-3 amp Unit-4It is

to clarify that Station tripped due to spurious operationLBB relay in Unit-

4 and not due to operation of Unit-3 LBB as indicated in PCSC

recommendations Unit-3 which was in service tripped as a consequence of

LBB ProtectionHow ever following actions performed in both Units

a) Trip coil-1 and Trip coil-2 circuit (including cable from protection panel

to GCB Marshaling Box)of GT Breakers of Unit 03 and 04 checked found

b) Integrity of Connecting cableconductor from Generating unit no3 and

also to its corresponding GT Breakers inspected and found ok

c) Regarding Spurious operation of Unit No04 LBB relay and its

timerChecked the operation of the LBB overcurrent relay with its external

Timer for repeated correct operations it was found that LBB Timer was

giving correct timing operation for 1 in 3 operations only ie for one of the

operation it was operating within 40ms compare to set value(200ms) hence

declared as faulty and the same has been replaced with new one later

operation of the new Timer checked and found okoperating for gt200mse

only With this cause for spurious operation of LBB and resulting in

complete outage of STRP has been identified and solved -----

Completed

2 In Unit -3MCR is working satisfactorilyit is to clarify that problem was

existing in Unit No4 AVR manual channel reference value of Generator

The Same has been replaced with spare one Manual channel AVR is

found to be Ok ------Completed

3 All the units AVRs Healthyness checked and found Ok -

Completed

4 Presently at GPHno stand alone Event logger exists Since the subject

requirement pertains to all the Generating units and in view of

Standardization of the complete system Networking of numerical relays

carried out and events are availble in networking system

Pending

(i) KPCL to ensure the integrity of the connecting cable conductor

from Generating Unit-3 to its corresponding GT breaker at their STR

(ii) KPCL to ensure the healthiness of Manual Current Regulator

(MCR) of Unit-3‟s AVR at their STR PH

(iii) KPCL to ensure the healthiness of AVR‟s of all Units of STR

(iv) KPCL to provide stand-alone Event Logger at their 220 kV STR

Spurious operation of LBB protection of line feeder

had led to tripping of 220 kV bus at Sharavathy Tail

Race power house

9-09-2016 at

1119 hrs

Pending

12-09-2016 at

1447 hrs

(i) KPCL to check and correct configuration settings of LBB

protection in all relays from which it was implemented at their 220

kV Varahi PH

(ii) KPCL to provide stand-alone Event Logger at their 220 kV STR

KPCLLBB protection operated and caused bus shut down at

Varahi PH

Pending

Partial disturbance occurred in central Kerala grid due

to overloading and tripping of 220 kV lines Loss of in-

feed to 220 kV Kalamassery 220 kV Brahmapuram

220 kV Ambalamugal 220 Pallom amp 220 kV Kochi

occurred Generation at Neriamangalam Panniar

Chengulam and Pallivasal also got affected during the

incident

(i) SLDC KSEB to put in place proper mechanism to ensure

adequate load-generation balance is maintained in their control area at

all times and due vigilance is exercised in operating an already

depleted transmission network

(ii) KSEB to put UFR in service at New Pallom end on 220 kV New

Pallom ndash Amabalamugal line as part of Kudankulam Regional

Islanding Scheme

Status received vide mail dated 14062017

LBB Protection system is in Bus bar Protection PanelThe Configuration

settings are checkedThey are as follows

Minimum operating primary current is 160A

Stage IIssue of Retrip to the feeder is 100ms after the action of main

distance protection Relayinitiation of LBB

Stage IIBus bar LBB Trip -200ms

Total time of LBB trip is 300ms from the time of occurrence of Line Fault

(i) KPCL to adopt the following VT fuse-fail logic for all 220 kV

lines emanating from NPH

ldquoUnder VT fuse fail condition distance protection shall normally be

kept blocked However upon detection of a fault (sensed by negative

sequence component) blocking of distance protection shall give rise

to operation of its inherent Over-Current protection set with a definite

time delay of 500 msecrdquo

(ii) KPTCL KPCL to revise Zone-2 Zone-3 and Zone-4 (reverse)

timings of DPR of all 220 kV lines emanating from Nagjheri PH in

line with Ramakrishna Committee guidelines

Triggering event was the fault on 220 kV Nagjheri

ndashKodasalli line-2 Both buses of 220 kV Nagjeri

power station of KPCL got

de-energized

62I1 KPCL Status received vide mail dated 14062017

1 Already settings are discussed with EE(RT) Hubli and soon relays will

be tested for VT fuse fail condition

2 Timings of Zones were set as per the recommendations of CE(RT) amp

RampD KPTCL Bangalore amp EE(RT) KPTCL HubliRegarding revision

of timings will be carried out in coordination with EE(RT) KPTCL

15-09-2016 at

1406 hrs

Complete outage at Varahi Hydro Power

Station

Disturbance in Kerala system Yet to be informed Pending

58I5 (GD)

58I7 (GD)

21-01-2017

at 0038 hrs

Complete outage of 220 kV Sharavathy

Tail Race PH

58I6 (GD)

Complete outage of 220 kV Nagjheri

substation of KPCL

Annexure-III

65II9 Tripping of 400220 kV ICT-1 at BTPS 13-05-2017 at

1941 hrs

ICT-1 got tripped on operation of LV side earth fault

protection during R-phase to earth fault in 220 kV

BTPS-Lingapur line

1 KPCL to review the need for providing separate non-directional

sensitive earth fault protection for ICT‟s at their BTPS station and

take steps to disable the same

2 For 220 kV BTPS ndashLingapura line KPCL to resolve issues relating

to PLCC carrier communication and put AR into service

KPCL Yet to be informed Pending

65III2 Tripping of 400 kV Hiryur-BTPS line-1 06-05-2017

at 1401 hrs

Y-phase to earth fault had occurred in line Direct

trip was sent from BTPS to Hiryur end

KPCL to introduce suitable delay (say 3 sec) for UVR tripping and

disable sending of DT to the other end on UVR operation at their

BTPS station

PendingMail received on 27-05-2015 (KPTCL) amp 29-07-2015

1Existing Back up relays will be replaced by numerical type distance

relaysProcurement is in tendering stage

2 Completed

3 Completed

KPTCL Mail recieved on 23-01-2016

1 Existing back up relays will be replaced by Main-2 protection LOI

issued Ms Alstom for taking up the works

KPTCL Mail Recieved dated 25-05-2016

Under the Scope of RampU The work will be taken up by Ms Alstom

shortly

1 ALSTOM make P442 type Numerical relays are supplied to the site

replacement of M-1 relays(OPTIMHO) by new relays will be taken up

shortly

KPCL Status received vide mail dated 10072017

1 Furnishing FIR amp TR of the tripping events as per the formats provided

by SRLDC

4 Refered to OEM for the tripping of Tie CB of Munirabad line on SOTF

protection

Pending

1 PCSC forum recommended KPTCL to replace the old static

distance protection relays with numerical relays

2 PCSC forum also requested KPTCL to provide a broken conductor

alarm indication in Control Room

3 Standing instruction needed to be given to the all substation

personnel for not changing the relay settings without approval of

RTMRT wing

Fault had occurred in 220kV

Mahalingapura-Narendra line-2 Due to the failure of

relay operation at Mahalingapura breakers at remote

end tripped which resulted in bus dead condition

1 KPCL to start furnishing FIR and TR of their tripping events as

per the formats provided by SRLDC

2 KPCL to check earth-mat resistance for 400 kV switchyard and

ensure that it is within prescribed limits

3 KPCL to set right operation of SER in CampI Control Room of Unit-

4 KPCL to furnish action taken wrt tripping of Tie-CB of

Munirabad line on SOTF protection OEM report in this regsrd may

be furnished

25-10-2014GD-1 at Mahalingapura Substation of

38GD31

63II10 Multiple trippings at 400 kV RTPS

substation of KPCL

16- 03-2017 at

0118 hrs

Bus-2 B-Ph differential bus bar protection operated

at 400 kV RTPS end tripping all the main breakers

connected to Bus-2

Annexure-III

Pending

Suspected mal-operation of 220kV side Rphase

over current relay

Line tripped on Yphase to earth fault from both the

20-12-2014

at 2220 hrs

KPTCL was requested to explore the possibility of providing AR

feature to this line and submit the remedial measures to the PCSC

Pending

KPTCL1 Till the completion of RampM works for bus bar and LBB protection

KPTCL shall explore the possibility of having split bus operation at

Ambewadi and submit the details of the same to PCSC forum

2 KPTCL shall provide the details of the tripping of Supa hydro

station connected downstream from 110 kV bus

220kV Sedam-

Tandur line

Triggering incident was B-phase to earth fault in

220kV Ambewadi- Nagzari line-1 B-pole of breaker

did not open at Ambewadi end LBB protection not

available at Ambewadi end All elements tripped on

Zone-2 from remote ends

01-12-2014Tripping of 400220kV

ICT-2 at Hoody

substation of KPTCL

Mail received on 27-05-2015 amp 29-07-2015

1 CampR panels of 500MVA ICT 1amp2 will be replaced under scheduled

RampM works

2 OampM personnel are instructed to take sufficient care in order to avoid

unwarrented trippings --- Completed

KPTCL mail received on 23-01-2016

1 New CampR panels(with numerical relays) erected for 500MVA ICT-1

amp2 under RampM work which will be commissioned shortly

1 New CRPs mounted in bay KIOSK commissioned under RampM works

KPTCL1 PCSC forum recommended KPTCL to replace the relay with a

different make

2 KPTCL was also requested to train the OampM personnel

adequately before performing any maintenance works to avoid such

unwanted trippings

PendingMail recieved on 29-07-2015

Carrier protection is being restored for 220kV Sedam-Tandoor line at

Sedam end After restoring the carrier protection AR will be enabled

KPTCL mail recieved on 23-01-2016

SEESCADA to update the latest status

Action is being taken to restore carrier protectionAR will be enabled once

carrier signal is restored

22-12-2014 at

2122 hrs

1 In view of operating 220kV Ambewadi SS in split bus mode action is

being taken up by KPTCL Problem in the 220kV bus coupler breaker is

attended and isolator overhauling work is under progress Spilt bus

operation at Ambewadi will be made possible at the earliest

2 ICT Protection system at Ambewadi and trippings occured at Supa GS

during the instance is checked up and remedial measures already furnished

in this regard

---- Completed

1 Action is being taken by KPTCL for operating Ambewadi in split bus

mode Problem in bus coupler breaker is attendedIsolator overhaulling

work is completedPTs are already provided to 220kV Bus-II After

commissioning of Bus-II PTs Ambewadi can be operated in split bus

mode Pending works will be completed within a months time

1 Bus-II PTs yet to be commissionedPlanned to complete before end of

April-2016

1 Yet to be attended

GD-1 at 220kV Ambewadi Station of

Annexure-III

1 KPTCL to provide Bus Bar protection and LBB protection at

Sedam Ss and furnish the status of their implementation to PCSC

2 KPTCL to implement AR feature on 220 kV Sedam-Tandur inter-

state line

Procurement of Bus bar and LBB protection is in the final tendering stage

2 Action is being taken to restore the carrier protection for 220kV Sedam-

Tandoor line AR will be enabled

1 Procurement of Bus bar and LBB protection is in the final tendering

Tandoor line AR will be enabled after restoration of PLCC

1 Bus bar protection panels pocured and erected at Sedam Wiring

testing commissioning is being taken upPlanned to complete by April

12-03-2015 at

751 hrs

1 KPTCL shall provide AR feature on Ambewadi ndash Ponda 220 kV

DC inter-state line

2 Till the completion of RampM works for bus bar and LBB protection

Ambewadi and submit the details of the

same to PCSC forum

1 Bus Bar protection will be provded under RampU

2 AR yet to be enabled

Fault occurred in 220kV Sedam-Shahpur line

All connected 220kV lines and transformers were

taken on 220kV North bus as South bus was under

shut down for conversion of strung bus to rigid bus

and isolator replacement under RampM works Failure

of HV side Y phase CT of 150MVA Transformer-3

occurred at Peenya Substation which resulted in

operation of Differential and HV REF protection The

failure of CT also resulted in a 220kV bus fault in

North Bus

KPTCL to revise distance relay settings at Nelamangala end for 220

kV Nelamangala ndash Hebbal - Peenya line ndash 1 for the effective line

length of 17 km These new settings can be appropriately reviewed as

and when the tie-arrangement at Hebbal is done away with

Pending

PendingKPTCL

30-09-2015 at

1041 hrs

Pending

Outage of 220kV Ambewadi station in

Karnataka

Pending

PendingKPTCL mail received on 23-01-2016

Will be complied in a months time

220kV Ambewadi-Nagjheri line-2 tripped on B-phase

to earth fault This resulted in loss of supply to 220kV

Ambewadi bus 220kV Ambewadi-Ponda line-1amp2

were hand tripped after deenergization of bus at

Ambewadi

Complete outage of 220kV Ambewadi

substation of KPTCL

42I2 (GD)

27-09-2015 at

42317 hrs

Fault in 220kV Ambewadi-Nagjheri line-2

Presentl 220kV Nelamangala -Hoody(ie nelamangala-Peenya-Hebbal -

Hoody line is made LIILO at Yelahanka sub station and breaker at

Peenya is kept open necessary modification in distance relay settings

adopted for new configuration

15-02-2015 at

1424 hrs

Complete outage of 220kV Peenya

Substation in Karnataka

R-Phase to ground fault occurred on 220kV Sedam-

Shahpur line Fault not cleared from Sedam end due

to stuck-breaker condition While the Sedam- Sahapur

line tripped from Shahapur end in Zone-1 the other

220 kv lines from Sedam tripped at remote ends in

Zone-2 This caused complete outage of 220kV

Sedam substation

42I1 (GD)

Complete outage of 220kV Sedam

substation of KPTCL

48I2 (GD)

48I3 (GD) KPTCL to fast-track providing AR on all 220 kV lines emanating

from Ambewadi SS to prevent Station shut-down on temporary faults

06-08-2015 at

451 hrs

220kV RTPS-Lingasugur line-2 tripped at TPS end

on operation of distance

protection zone-1 400220kV ICT-2 got tripped on

operation of earth fault

protection 220kV RTPS-Lingasugur line-1amp3 tripped

on distance protection zone-2 and zone-3

respectively Due to tripping of ICT-2 the running

units got overloaded and it was mentioned that under

frequency occurred as units are on load control The

Units got tripped on under frequency

KPTCL to activate non-directional Over Current protection with a

time delay of 600-800 msec for Fuse

failure condition at Lingasugur

KPTCL Status received vide KPCL mail dated 10072017

LV earth fault relay had an additional default Ef setting having a definite

time which resulted in tripping of ICT-2 and the same was rectified and

already complied

Pending

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

bus at Sedam Ss

2 KPTCL to implement AR feature on 220 kV Sedam-Tandur

inter-state line

27-01-2015 at

800 hrs

Complete outage at 220kV Sedam

Substation of KPTCL (GD-1)

Tripping of Unit-1amp2

along with 400220kV

ICT-2 at Raichur TPS

47II13

Annexure-III

52I3 (GD) Complete outage of 220kV Shimoga

substation

22-02-2016 at

1503 hrs

220kV Bus Bar protection operated during failure of

R phase CT in DVG-2 line bay

KPTCL to operate 220 kV Shimoga on multi-bus operation under

normal conditions put it on single-bus operation only under

emergency conditions

KPTCL KPTCL Mail received dated 25-04-2017

Replacement of existing BBP by new BBP with 4 zone protection is being

taken up under RampU

Pending

56II6 Tripping of 220kV Ambewadi-Ponda

(Xeldam) line-1

10-06-2016 at

1333 hrs

Line tripped on Y-E faut due to DPR Z1 operation KPTCL to keep AR for Ambewadi ndash Ponda (Xeldam) line-1 in

service with immediate effect

KPTCL Yet to be informed Pending

59II13 Tripping of 220 kV Bidadi (PG) - Bidadi

lines - 1amp2

02-10-2016 at

1032 hrs

Line-2 tripped in DPR Zone-2 and Line-1 tripped on

operation of EF protection from Bidadi end

KPTCL to resolve PLCC carrier communication issues on 220 kV

Bidadi ndash Bidadi-PG DC lines and subsequently restore Zone-2

timing to normal values

1 KPTCL to configure all DR‟s and EL‟s at 400 kV Guttur SS so

that they will also get triggered for BBP operation

2 KPTCL to ensure time-synchronization of all DR‟s and EL‟s with

GPS at their 400 kV Guttur SS

KPTCL17-01-2016 at

1853 hrs

Pending

Yet to be informed PendingKPTCL

30-09-2015 at

1041 hrs

Substation of KPTCL

Multiple tripping at 400kV Guttur sub-

station

Karnataka

29102015 at

1434 hrs

Substation of KPTCL

220kV Peenya-Nelamangala-3 tripped on B-E fault at

both ends At the same time 220kV Peenya-

Nelamangala-4 tripped on R-Y fault only at

Nelamangala end and was in service from Peenya

end Due to tripping of these two lines 220kV Peenya-

Nelamangala-2 tripped on overcurrent protection

KPTCL to furnish a report on the tripping of 220 kV Peenya-

Nelamangala line-4 Nelamangala detailing the remedial measures

taken including the settings adopted for Z1B (Zone extension) and

Power Swing Block

Pending220kV Nagjheri-Ambewadi line-1 tripped at 1333

hrs due to B phase to earth fault Ambewadi was

radially fed from Nagjheri power station through

220kV Nagjheri-Ambewadi line-2 Tripping of this

line caused 220kV Bus shut down at Ambewadi and

remaining lines and transformers were hand tripped

Ambewadi

Yet to be informedKPTCL

KPTCL Mail received dated 25-05-2016

SEE RTC Bangalore to update the status

Providing numerical bus bar protection to 400kV buses and GPS time

synchronising equipment at Guttur is considered under RampU Work is

awarded to Ms Alstom execution will be taken up shortly

GPS and accessories will be supplied during May 2017 expected to

complete the work within a month after supply of materials

1KPTCL to take steps to provide busbar protection at their 220 kV

Chikkodi inter-regional substation and furnish a time-line for the

2KPTCL to review distance protection settings for 220 kV Chikkodi

ndash Kudachi line

3KPTCL to furnish equipment failure report of the current incident to

PSEampTD Division of CEA with a copy marked to SRPC

1 KPCL to provide AR on all 220 kV lines emanating from Nagjheri

2 KPTCL to provide AR on all 220 kV lines emanating from

Ambewadi SS

Failure of Lightning Arrestor of Y-phase Line Reactor

of 400kV Guttur-Hiriyur line-1 and line tripped on

distance protection Zone-1 Bus-bar protection of

400kV Bus-2 at Guttur substation also got operated

during the event sensing this through fault 400220

kV ICT-1 amp 2 at Guttur 400kV Kaiga-Guttur-2

Guttur-Narendra-2 400kV Guttur-Hiriyur-2 and

400kV Guttur-Munirabad which are on 400kV Bus-2

got tripped during the incident 400kV Guttur-

Narendra-1 which was on Bus-1 also tripped at the

same time

49I13 (GD)

Triggering incident was failure of B-ph PT of 220kV

Bus-2 (western bus) at 220KV Chikkodi substation

220KV Chikodi- Belgaum-I line tripped on DEFR

(Inst) 220KV Chikkodi-Kudachi line tripped on

Distance protection and also 100MVA transformer-2

tripped on EF protection

57II1 01-07-2016 at

0303 hrs

Tripping of 220 kV Chikkodi-Mudshingi

and 220 kV Chikkodi-Talandage lines

51II21

16-03-2016 at

1139 Hrs

Annexure-III

62II3 Tripping of 220 kV Bus 2 and connected

elements (220kV HAL 1 and 2

400220 kV ICT- 1 2 and 22066 kV

ICT-2) at 400220 kV Hoody substation

of KPTCL (Load loss 590 MW)

09-01-2017 at

2306 hrs

Failure of R-phase CT of 220 66 kV transformer-2 at

220kV Hoody end resulted in a bus fault in 220kV

Bus-2 Fault was cleared by backup protection of

ICTs (220kV lines were being radially operated) due

to absence of busbar protection

1 KPTCL to provide Busbar protection at their 220 kV Hoody SS at

the earliest

2 KPTCL to furnish an Equipment Failure Report on CT failure to

CEA with a copy marked to SRPC

KPTCL KPTCL mail received dated 25042017

Numerical BBP is being provided under RampM works

Pending

64II9 Tripping of 400 220 kV ICT-2 and 3 at

Hoody substation of KPTCL

26-04-2017 at

1540 hrs

ICT-2 tripped on suspected mal-operation Oil surge

relay of B-phase Transformer ICT-3 tripped due to

overloading

KPTCL to put in place a suitable SPS at their 400 220 kV Hoody SS

that takes care of over-loading of the other ICT when one ICT out of

ICT‟s ndash 2 amp 3 trips at the earliest and furnish the details of

implemented SPS to PCSC forum

65II17 Tripping of 400220 kV ICT - 1 amp 3 at

(Load Loss 750 MW)

26-05-2017 at

1230 hrs

R phase limb of ICT-1 bank pre-close supervision

contact of trip coil -2 had arc over ICT-3 got tripped

on over-loading

KPTCL to furnish compliance report on the recommendations given

in PSAG-18 meeting to PCSC forum

Complete outage of 220kV Nagjheri

power station and 220kV Ambewadi

substation of KPTCL

51I3 PendingStatus informed during Special Meeting held on 03062016

1 KPTCL informed that the matter had been taken up with concerned Line

Operation and Maintenance wing to carry out corridor clearance and

maintenance as per schedule to avoid frequent line faults in this corridor A

letter had also been addressed to Chief Engineer Bhagalkot zone to ensure

lines in amp around Kali complex are maintained in healthy condition ---

Completed

2 KPTCL assurd that the final modified SPS would be implemented at

Nagjheri PH at the earliest ------ Pending

3 KPCL informed that Nagjhari- Kodasalli Lines 1 amp 2 had been kept in

service since 23052016 0806hrs ---- Completed

Modifications to be carried in Nagzari SPS logic is submitted to

SRLDCSRPC for verification and approval

1 Will be reviewed in consultation with EE(RT) KPTCL Hubli

2 Both the lines are in charged condition

KPCL KPTCL 1 To avoid tripping of transmission lines on transient faults KPCL

KPTCL is recommended to carry out periodic patrolling of lines and

ensure their proper maintenance by carrying out jungle bushing

clearance and trimming of tree branches within the RoW of

transmission lines as per the SRPC transmission line patrolling

guidelines (available under the menu item All Uploads Operation

Miscellaneous Transmission Line Patrolling Protocol

Guidelines for Southern Region on SRPC website)

2 KPCL KPTCL to review operation of SPS at NPH for

functionality (reduction of generation with tripping of evacuating

lines) and healthiness

3 KPCL to put 220 kV Kodasalli - Nagjheri DC lines into service if

more than 200 MW generation from Kali Complex (with Nagheri

Contribution not less than 50 MW) is ensured on sustained basis

220kV lines from Nagjheri power house started

tripping from 1100 hrs due to fault in lines The

sequence of tripping is shown in SOE list At 1233

hrs 220kV Narendra-Ambewadi lines-1amp2 got

tripped which resulted in loss of evacuation path to

Nagjheri station resulting in tripping of running Units

and complete outage at Nagjhheri power station

220kV Ambewadi station also got de-energized due

to tripping of source feeders ie 220kV Narendra-

Ambewadi-1amp2 and 220kV Nagjheri-Ambewadi-

22-02-2016 at

1236 hrs

Pending

KPTCL in coordination with

PGCIL (SR-II)

replaced

KPTCLLine tripped at Hiryur end due to direct trip receive

and was holding from Guttur

KPTCL mail received dated 25042017

KPTCL to provide numerical Busbar Protection at their 220 kV

Somanahalli SS at the earliest

Tripping of 400 kV Neelamangala-

Hoody line-1

KPTCL to carry out the following for the line under consideration

replaced

Tripping of 400 kV Guttur-Hiryur line-1 10-10-2016 at

315 hrs

62II5 Tripping of 220 kV South Bus and

connected elements (220kV HSR 220kV

Nagnathpura 220 kV Harohalli 220 kV

Subramanyapura 220 kV Tataguni 220

kV Mallur and 400220kV ICT-2 and 3)

at 400220kV Somanhalli substation of

(Load loss 850 MW)

20-01-2017 at

1434 hrs

Triggering incident was fault in 66 kV Somanahalli -

Bannerghatta line and fault was cleared by operation

of Back-up OCR at Somanahalli end

15-02-2017

at 1344 hrs

Line tripped at Hoody end on direct trip receive and

was holding from Neelamangala end

Yet to be informed

Annexure-III

56I3 Complete outage of 220kV Ambewadi

Substation of KPTCL

24-06-2016 at

2057hrs

B phase to earth fault had occurred in 220 kV

Ambewadi-Ponda line-2 Fault was cleared by

tripping of feeders from remote end

1KPCL amp KPTCL to furnish an action taken report on the

recommendations given by PSAG-16 to PCSC forum

2KPTCL to keep AR for Ambewadi ndash Ponda line-2 in non-auto

mode (ie only 3-ph trip should get extended on occurrence of a

fault) till the line is closed from Ponda end

KPCLKPTCL Yet to be informed Pending

station of KPTCL and 220kV Nagjheri

of KPCL

Ambewadi Narendra line-2 tripped on fault and

220kV ambewadi Narendra line-1 tripped due to over-

loading Running Units at Nagjheri also tripped during

the event due to tripping of evacuating lines

KPCL KPTCL18-03-2016 at

1440 hrs

1 TANGEDCO to replace existing Check-Zone relay with a new one

possessing required performance

2 TANGEDCO to take steps to provide numerical busbar protection

at their 220 kV Tuticorin TPS TANGEDCO may also explore

providing dual CT‟s (on either side) for all BS breaakers at the time

of commissioning of numerical BBP if there were no space

constraints

3 TANGEDCO to take steps to provide for standalone Event Logger

(EL) and standalone Disturbance Recorder (DR) with automatic

downloading facility to a centralized server

Failure of Bus Section-I Y-ph CT resulted in

operation of bus-bar protection for Bus Sections -I amp

II Running Units1 4 and 5 230 kV Kayathar

230kV Kudankulam 230kV Sterlite Station

Transformer-1 2 amp 3 got tripped during the incident

Unit ndash 2 amp 3 were not in service

22-02-2017 at

0616 hrs

KPCLKPTCL

25-01-2017 at

2236 hrs

R-phase to earth fault due to de-capping of insulator

Auto-reclose attempt was unsuccessful

Tripping of ICT-3 at Raichur Substation

TANGEDCO

Pending

Tripping of running Units amp 230kV

feeders at Tuticorin TPS of TANGEDCO

(Gen Loss 640 MW)

1 KPCL to furnish a report on the reasons for Unit-6 tripping at

Nagjheri PH

2 KPCL KPTCL to modify suitably the SPS at Nagjheri Power

House such that it would also factor in the over loading of Ambewadi-

Narendra lines

Pending53I3 (GD)

15-03-2016 at

1228 hrs

ICT-3 tripped due to operation of back-up earth fault

protection during fault in 220kV RTPS-Raichur line-

KPCL KPTCL to check the ICT‟s back-up (high-set) protection

settings and ensure that they operate with a time delay of 100 msec

TANTRANSCO mail dated 12042017

1 The recommendation will be ensured AR logic will be configured in

Distance Protection relay itself instead of BCU OEM has been addressed

2 Post triggering period of 2 sec to cover AR operation in DR time scale

will be provided

TANTRANSCO mail dated 01062017 amp 15062017

Main-1 amp 2 relays will be replaced for the requirement of more output

contacts for AR logic implementation

is being provided

TANGEDCO1 TANGEDCO to take properly configure AR logic at NCTPS-II in

that in case of unsuccessful auto-reclsoure three-phase trip shall be

given along with AR block

2 TANGEDCO to configure all protection relays DR‟s time scale at

NCTPS-II for a post-triggering period of 2 sec to capture events such

as complete AR operation

Tripping of 400 kV NCTPS-

SVChatram line-2

1 Tripped since there was evacuation problem and there were only two

lines NA-1 and NA-2

TANGEDCO mail dated 15042017

1) New Relay is tested and ready for replacementNow all 5 units are in

serviceThe relay will be replaced when lesser units are in service ---

Pending

2a)Steps are taken to renovate amp mordernization of all the control panel

into Numerical based control panels --- Pending

2b) Since 230 KV indoor switchyard has no spare space providing dual

CT`s is not fessible -- Completed

3) Procurement of EL amp DR is under progress --- Pending

1) Check zone New Relay is replaced on 17042017 -- Completed

2 Pending

3 Pending

SEESCADA to update the status of healthiness of carrier protection of

220kV RTPS-Raichur 1 amp2 lines

Details sought from KPCL for review of ICTs back up (high set) proection

settings as suggested KPCL is yet to furnish the details required to give

the revised settings

As requested by EEE (protection) CEERT KPTCL the details were sent

to through e-mail dtd 08082016 After receipt of reply from KPTCL will

be implemented accordingly

62V3 Pending

Pending

Tamil Nadu

Annexure-III

05-09-2015 at

1404 hrs

TANTRANSCO to take suitable measures like installing more stub-

towers along 230 kV OK Mandapam ndash Myvady line to avoid

excessive sag due to over-loading

TANTRANSCO PendingComplete outage of 230kV Palladam 230 kV

Othakalmandapam Ss 230 kV Coimbatore Ss 230

kV Thudialur and 230 kV Sadayapalayam Ss

Pending

Disturbance in 220kV Tamilnadu system48I1 (GD)

TANTRANSCO TANTRANSCO vide their mail dated 240615 informed that different

relays in Main-I amp Main-II would be ensured at the earliest

Mail recieved on 24-07-2015 19-02-2016 and 24-03-2016

Different relays in Main-I amp Main-II will be ensured

TANTRANSCO Not feasible in the existing SAS sub stations Hence

exemption may be given for these sub stations

Mail received on 20-05-2016 16-06-201625-07-2016 amp 24-09-2016

As discussed in the 52nd PCSC meeting Swapping of Relays between two

stations is not feasible in the existing SAS sub stations Hence exemption

may be given for these sub stations

Status received vide mails received on 10-11-2016 amp 20122016 amp

12042017 amp 01062017 amp 15062017

Different make Relays will be ensured for Main-I amp II relays at Alamathy

TANTRANSCO Mail received on 19-02-2016 24-03-2016 and 27-04-

230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal

Nagar Line restringing will be carried out along with the above proposal

Mail Received on 20-05-2016 16-06-201625-07-2016 amp 24-09-2016

12042017 amp 01062017 amp 15-06-2017

29-03-2015 at

1529 hrs

43II5 Line-2 tripped on R-phase to earth fault

Line autoreclosed at SVChatram end and failed to

reclose at Alamathy end Bphase to earth fault in line-

1 Line tried for Ar but due to permanent fault line

did not reclose ICT tripped on operation of over flux

protection

TANTRANSCO was requested to swap the relays between two

stations so that

Main-1 and Main-2 will be of different make at each station

Tripping of 400kV

Alamathy-

SVChatram line-1amp2

and 400230kV ICT

at SVChatram

Annexure-III

14-09-2016 at 1113Hrs

Bus Bar Protection (Zone-2) of 230 kV Bus-B got operated at Alamathy Station during fault in 230 kV

Alamathy-Korattur feeder

51I1 (GD)

12-05-2016 at

1215 hrs

Fault had occurred in 230kV Madurai-Sembatty line

Trip from distance relay was not extended to breaker

due to protection DC fail LBB protection got

operated resulting in a busbar trip at 230kV Madurai

substation All elements got tripped as there is a

single bus operation at 230kV Madurai Ss

58II17

TANTRANSCO

TANTRANSCODifferent type and Make of distance protection relays to be provided for Main-I amp Main-II protection for 230kV feeders at 400 kV Sunguvarchathiram amp 230 kV Sunguvarchathiram Substation [Carry-Over from Protection Audit Recommendations]

Mail recieved on 25-07-2016 amp 24-09-2016

TANTRANSCO Auto Transformer-2 HV side Bus isolator C-phase

support insulator of 230kV Southern Bus was replaced and Bus Bar

Protection scheme was restored on 12052016

12042017 amp 01062017 amp 15-06-2017

CT is not available in the Bus Coupler bay for zone segregation CT latch

relay is to be provided for all bays for zone segregation

TANTRANSCO mail received on 24-03-2016

CMR relay for extending LBB protection was released and LBB extended

from Distance Protection relay directly CT is not available in the Bus

Coupler bay for zone segregation However during commissioning of third

ICT Bus section Breaker will be provided for zone segregation Numerical

BBP relay will be provided

Status received vide mails recieved on 27-04-2016 and 20-05-2016 16-

06-2016 25-07-2016 24-09-201610-11-2016 amp 20122016 amp

12042017 amp 01062017 amp 15-06-2017

CT is not available in the Bus Coupler bay for zone segregation However

during commissioning of third ICT Bus section Breaker will be provided

for zone segregation Numerical BBP relay will be provided

PendingComplete outage of 230kV Madurai Ss

(Chekanaurani) of TANTRANSCO

TANTRANSCO

Mail received on 10-11-2016 amp 20122016

1 The Bus Bar Protection scheme will be tested for healthiness including

the CT circuits

2 High impedance BBP relay will be replaced by Numerical relay

Status received vide mails dated 10012017 amp 12042017 amp

01062017 amp 15-06-2017

1 The Bus Bar Protection scheme was tested for healthiness including the

CT circuits AREVA make CTs in Alamathy SS are having different

kneepoint voltage for the cores CT cores of higher knee point voltage has

been choosen for BBP in 230kV Korattur 230kV OPG-1 amp 230kV OPG-

2 feeders on 29112016 ---- Completed

2 High impedance BBP relay will be replaced by Numerical relay ---

Pending

TANTRANSCOMultiple tripping at 230 kV Alamathy Station

Pending

1 TANTRANSCO to check the healthiness of BBP relay by conducting stability test and take appropriate remedial action like

increasing voltage settings ensuring the healthiness of CTrsquos using

CTrsquos with similar characteristics (equal saturation effects amp equal winding resistances) etc at their 230 kV Alamathy SS

2 TANTRANSCO to replace the existing high-impedance BBP relay

with its low-impedance numerical variant so as to accommodate

variation in CT characteristics at their 230 kV Alamathy SS

TANTRANSCO to take steps to provide double-bus operation at

their 230 kV Gummidipoondi SS

Pending

Complete outage of 230 kV

Gummidipoondi Station of

TANTRANSCO

19-01-2016 at

1156 hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV

Southern Bus occurred at Gummidipoondi station At

the time of fault Bus bar protection relay was not in

service for pre-commissioning testing of Auto

Transformer-2 All feeders got tripped due to

operation of zone-2 protection from remote ends

TANTRANSCO1 TANTRANSCO to examine the feasibility of providing two main-

zone operation for bus bar protection by exploring various alternatives

like replacing existing bus-coupler CB with a hybrid bus-coupler CB

that comes with inbuilt CT replacing existing BBP relay with another

suitable relay that supports two main-zone operation and implement

the same

Busbar protection got operated for a fault in 230kV

Mywadi-Anaikadavu line

21-12-2015 at

628 hrs

Complete outage of 230kV Mywadi

station of TANTRANSCO

50I3 (GD) TANTRANSCO Mail received on 19-02-2016 and 24-03-2016

Revision of Bus Bar Protection setting was carried out The stabilizing

voltage setting was raised from 410 to 450 volts After completing the

necessary test the bus bar protection put in to service on 29122015

Revision of Bus Bar Protection setting was carried out After completing

the necessary test the bus bar protection put in to service on 29122015

Provision of Bus Coupler bay arrangement was included in the

Upgradation works proposed and the same was sanctioned by MoP

through PSDF

Numerical relay allotted and being commissioned

Numerical BBP relay was commissioned on 02022017

Status received vide mail dated 12042017 amp 01062017 amp 15-06-

through PSDF

01062017 amp15-06-2017

Different make Relays will be provided for Main-I amp II relays at

Sunguvarchatram end in a phased manner

Pending

1 TANTRANSCO to provide split-bus operation with bus

sectionalizer CB for their 230 kV Madurai (Chekanurani) SS

2 TANTRANSCO to provide two main-zone operation for the

numerical BBP that is being commissioned

3 TANTRANSCO to examine the feasibility of providing Re-Trip

feature for the LBB protection and accordingly take steps for

implementing the same

55I1 (GD)

Annexure-III

58II17 Mail received on 10-11-2016 amp 20122016

the CT circuits

01062017 amp 15-06-2017

Pending

TANTRANSCOMultiple tripping at 230 kV Alamathy

Station

15-09-2016 at

2214 hrs

Bus Bar Protection (Zone1) of 230kV Bus-A got

operated at Alamathy Station during fault in 230 kV

Alamathy-OPG-1 feeder

1 TANTRANSCO to check the healthiness of BBP relay by

conducting stability test and take appropriate remedial action like

CTrsquos with similar characteristics (equal saturation effects amp equal

winding resistances) etc at their 230 kV Alamathy SS

Pending

Annexure-III

6414 Complete outage of North Chennai TPS

26-03-2017

at 2314hrs

Tripping of evacuating lines due to fault led to

tripping of running Unit at NCTPS Stg-1

1 TANTRANSCO to take steps to complete insulator replacement

works on the 230 kV lines owned by them in NCTPS area within 6

months

2 TANTRANSCO to take steps to implement AR on all 230 kV lines

emanating from NCTPS-I at the earliest

TANTRANSCO Yet to be informed Pending

65II1 Tripping of 220 kV Idukki ndashUdumalpet

05-05-2017 at

1702 hrs

Line tripped due to B-N and R-N fault in line 1 TANTANSCO to correctly configure AR logic at Udumalpet so

that in the event of 3-ph trip being given during AR dead-time the

relay will not try for auto-reclosure

2 TANTRANSCO to keep AR dead-time as 1 sec for all 220 kV amp

above transmission lines

58II17

44I1 (GD)

the CT circuits

01062017 amp 15-06-2017

Pending

KSEB Mail received vide dated 17012017

1 110 kV bus bar protection progressing ----Pending

2 Connection of 220kV earth mat and 110 kV plate earthing system

completed---- Completed

3 Redundancy of 110V DC system in progress Complete independent

redundancy is not practical for the time being 48 V DC redundancy was

already there----Pending

4 Instead of stand alone event logger SCADA system of 110 kV feeder is

expected to be completed by the end of 2017 SCADA system of 220kV

side will be taken up after that----Pending

28-04-2015 at

1230 Hrs

1 Reducing the sensitivity of REF protection of Unit 4 5 6 at Idukki

PH - Generation wing is planning to purchase new transformer

management relays with low impedance REF protection Purchase

procedures initiated ---------Pending

2 The replacement repair of faulty breakers are under the consideration of

Generation wing Breakers will be replaced repaired in a phased manner

Unit 3 breaker was replaced with available breaker from the 220kV

IDMD feeder The 220kV CBs of unit 2 and unit 3 will be replaced with

in two months

3 No abnormalities were noticed in the PLCC equipment at New Pallom

station It is kept under observation

1 Purchase procedures is still in progress

2 Replaced

3 PLCC equipment Tested and found OK

1 Even though repeated plans to have a joint inspection with MsABB

who is the OEM of the relay panel for replacing the relays with numerical

ones the same could not become successful Finally the inspection has

been fixed on 15032016 It has been planned to replace existing REF

protection with low impedance ones after retrofitting the numerical ones of

1Generation wing is planning ti provide low impedance REF protection by

retrofitting numerical ABB make transformer management relay in the

existing panel ---- Pending

2Faulty breaker of Unit3 has been replaced ---- Completed

3PLCC equipments in the feeder were checked and found OK ------

Completed

TANTRANSCO

Complete outage of Idukki Hydro Power

Station (GD-1)

Multiple tripping at 230 kV Alamathy

Station

15-09-2016 at

2214 hrs

58I1 (GD) Complete outage of 220 kV Kalamassery

Substation

23-08-2016

at 1120 hrs

Triggering incident was conductor snapping in 110

kV Kalamassery- Kaloor feeder

KSEB to take steps to provide the following at their 220 110 kV

Kalamassery SS

1 Busbar protection at 110 kV level

2 Connecting 220 kV and 110 kV sides on to a common earthmat

3 Redundant DC supply for both protection (220 V) and

communication (48 V) applications

4 Stand-alone Event Logger

Pending

220 kV breaker of unit-3 at Idukki Power

house flashed and bus differential protection

acted All Generators (6Nos) along with all

220 kV feeders tripped during the incident

1 KSEB to reduce sensitivity of REF protection appropriately at

Idukki PH

2 KSEB to replace repair the faulty breaker

3 KSEB to check the PLCC equipment at New Pallam and inform

the remedial measures taken to PCSC forum

Kerala

Pending

(Recommendat

ion No1)

Annexure-III

08-05-2016at

457 hrs

Tripping of 400kV Hyderabad - N‟sagar

PGCIL (SR-I amp SR-II)

PendingLine tripped on operation of over-voltage protection at

Hyderabad end and Direct Trip was received at

N‟sagar Over-voltage Stg-2 operation was observed

in EL of Hyderabad station

55II5 1PGCIL (SR-I) to properly configure EL‟s at Hyderabad station

with time-scale resolution up to msec further DR‟s should also be

configured for showing both Analog and Digital data with properly

defined X-axis and Y-axis scales

2PGCIL (SR-I) to follow the FILE Naming Nomenclature provided

by SRPC in naming various tripping files (FIRDRELTR) being

uploaded in SRLDC‟s Tripping Monitor System (TMS) portal

PGCIL (SR-I) Yet to be informed

Annexure-III

55II9 Tripping of HVDC Gazuwaka pole-2 19-05-2016 at

1141 hrs

Pole tripped on operation of differential current

protection of east side of Pole-2

PGCIL (SR-I) to take up the issue of differential protection operation

of converter transformer on low voltage fluctuations with their OEM

and submit a detailed report on it

PGCIL (SR-I) Yet to be informed Pending

56II11 Tripping of HVDC GazuwakaPole-2 19-06-2016 at

520 Hrs

HVDC Pole-2 got tripped on operation of Bus

differential protection

PGCIL (SR-I) to get the tripping of HVDC Pole-2 tripping on Win-

Bus differential protection thoroughly investigated for correctness of

operation and submit a report thereon

56III7 Tripping of 400 kV Khammam-N‟sagar

line-1

05-06-2016 at

2241 hrs

Line tripped on B-phase to earth fault Line auto-

reclosed successfully at N‟sagar and failed to auto-

reclose at Khammam

1PGCIL (SR-I) to configure DR amp EL at N‟sagar (Tallapalli) end so

that full operation of AR is captured

2PGCIL (SR-I) to investigate the reasons for non-operation of AR of

Tie-CB at N‟Sagar end and resolve them suitably

58II13 (GI) Tripping of 400 kV Raichur-Gooty line-1

and 400 kV Gooty-Tumkur line-2

01-09-2016 at

517 hrs

400kV Gooty-Raichur line tripped at Gooty end only

and was holding from Raichur 400kV Gooty-Tumkur

line-2 tripped on over voltage

PGCIL (SR-I) to check the operation of OVR relays at their Gooty

SS and properly configure lines‟ DRs amp ELs so that events pertaining

to OVR (Stage-I amp Stage-II) operation (START amp TRIP) get

explicitly recorded

58II14 (GI) Tripping of 400 kV Gooty-Tumkur line-2 02-09-2016 at

2156 hrs

Line tripped on operation of over-voltage protection at

Gooty end and Direct Trip was received at Tumkur

explicitly recorded

61II4 Tripping of HVDC Gazuwaka Pole-2 05-12-2016

at 1503 hrs

Pole-2 tripped due to tripping of AC filter banks

which was due to voltage disturbance in eastern bus at

Gazuwaka

PGCIL (SR-I) to refer the instant trippings to their OEM to ensure

that the settings adopted for pole trippings for low-voltage power

swing and ferro-resonance phenomena are in order and have been set

properly A copy of the OEM‟s reply in this regard shall be furnished

to PCSC forum

62II4 Tripping of 400 kV Gazuwaka-Vemagiri

(PG) line and 400kV Vemagiri(PG)-

Nunna line

18-01-2017 at

2203 hrs

400 kV Gazuwaka - Vemagiri (PG) line and 400 kV

Vemagiri (PG) - Nunna line got tripped due to Direct

Trip receive at Gazuwaka and Vijayawada respectively

PGCIL (SR-I) to configure triggering of DR amp EL for SF6 gas

compartment Zone trip with suitable legend

63II11 Tripping of 765 kV Vemagiri-Srikakulam

line-1 and 765400kV ICT-1 at Vemagiri-

16-03-2017 at

1023 hrs

Line-1 and ICT-1 which are in the same diameter got

tripped due to operation of Tie bay gas

compartment trip

1 Since tripping of elements on Gas Compartment Trip has been

observed frequently in the past few months at 765 400 kV

Vemagiri SS PGCIL (SR-I) shall furnish a comprehensive report

detailing the remedial measures taken including OEMrsquos suggestions

to prevent their occurrence

PGCIL (SR-I)12-09-2016 at

1203 hrs

Line tripped on Direct Trip receipt at Ramagundam

end and line was holding from Warangal end

Pending58IV1

400 kV Gazuwaka-Vemagiri (PG) line tripped on Y-E fault However for 400 kV Gazuwaka-Vemagiri (PG) line Direct Trip was received at Gazuwaka after

250ms of occurrence of fault and fault was

persistent for 250ms Then Over-Voltage Stage-1 protection operated from Vemagiri (PG) end in 400 kV Vemagiri (PG) - Nunna line and tripped it

For the line under consideration the following shall be carried out

by PGCIL (SR-I) in coordination with NTPC-Ramagundam

I)End-to-end communication for DT permissive amp other signals may

be ensured by testing at both the ends

II)Healthiness of PLCC system components (hardware and software)

at both ends shall be checked and faulty components shall be

repaired replaced

Yet to be informedTripping of 400 kV Ramagundam-

Warangal line

Yet to be informed05-01-2017 at 1305 hrs

Tripping of 400kV Gazuwaka - Vemagiri (PG) line and 400 kV Vemagiri (PG ) - Nunna line

1 PGCIL (SR-I) to ensure time-sync of all protections relays at their Vemagiri Gajuwaka and Vijayawada substations2 PGCIL (SR-I) to check OVR settings for correctness of operation

along with proper drop-off to pick-up ratio (gt 097) and configure

OVR_START event in the corresponding Relay BCU Event Logger for all 400 kV lines emanating from their Vemagiri (PG) SS

PGCIL (SR-I) Pending

Annexure-III

64III16 Tripping of 76 5kV Kurnool-Nellore PS

line-2

27-04-2017 at

2222 hrs

R-phase to earth fault had occurred in line Auto-

reclose was successful at Kurnool end and breaker

at Nellore PS end tripped and did not attempt for

auto-reclose

For the line under consideration PGCIL (SR-I) to Configure Event

Logger (EL) to record events at msec level

65II15 Tripping of HVDC Gazuwaka Pole-1amp2 25-05-2017 at

0945 hrs

HVDC pole-1 got tripped due to operation of South

filter inter zone protection and HVDC pole-2 got

tripped due to operation of differential protection

PGCIL (SR-I) to furnish detailed report on the events that led to

tripping of HVDC Poles ndash 1 amp 2 including remedial measures taken

to PCSC forum Further the OEM report wrt tripping of HVDC

Pole-2 shall also be furnished

65III5 Tripping of 765 kV Raichur-Solapur line-

07-05-2017

at 1918 hrs

Y-phase to earth fault Auto-reclose was successful

at Solapur and breakers at Raichur end got tripped

PGCIL (SR-I) to configure Event Loggerrsquos time-resolution up to

millisec level in all protection relays at their 765 400 kV Raichur SS

55II7 Tripping of 400kV Kudgi PG (Narendra

New) - Narendra-PG line-2

18-05-2016 at

1625 hrs

line tripped on B-phase to earth fault and line auto-

reclosed successfully from Narendra end Line tripped

from Kudgi-PG due to operation of over-voltage stage-

PGCIL (SR-II) to properly configure dead-time of AR (typically 1

sec) on all lines emanating from Narendra (PG) substation

PGCIL (SR-II) Yet to be informed Pending

54II3 Tripping of 400kV Sriperambudur -

SVChartam and 400kV Nellore-

Sriperambudur line-1

05-04-2016 at

0011 hrs

400kV Nellore-Sriperambudur line-1 tripped on a R-

phase to earth fault 400kV Sriperambudur-

SVChatram line tripped at Sriperambudur end only

on operation of over current protection

PGCIL (SR-II) to check and revise Pole Discrepancy Relay (PDR)

time setting appropriately based on the type of AR scheme being

implemented at their 400 kV Sriperambudur SS

54III3 Tripping of 400 kV Kalvindapattu-Vallur

10-04-2016 at

1459 hrs

R-phase to earth fault had occurred in line Auto

reclose attempt is unsuccessful auto-reclose could not

be established from provided DR EL

PGCIL (SR-II) to furnish a report on the tripping event detailing the

reasons for unsuccessful AR operation at Kalvindapattu end and the

remedial action taken to restore AR to normalcy

55II17 Tripping of HVDC Talcher-Kolar pole-1 30-05-2016 at

0949 Hrs

Failure of main CT of AC filter (20C08A) occurred

and it in turn caused the operation of filter bank

differential protection HVDC Pole-1 got tripped on

group Differential protection operation

PGCIL (SR-II) to take up the issue of Pole-1 tripping on Group

Differential Protection (Stage-II) due to multiple commutation failures

with their OEM and furnish a report on it

56II8 Tripping of HVDC Talcher-Kolar Pole-1 17-06-2016 at

1635 Hrs

Talcher-Kolar HVDC Pole-1 got tripped on line fault

and Pole-2 went to ground return mode with 150MW

PGCIL (SR-II) to address amp resolve DTPC and fibre-optic link

related issues raised by KSEB at Thrissur Madakathara substations

and conduct a mock-test in coordination with KSEB to verify integrity

of signal transmission from Kolar to Thrissur Makadathara

64II14

PGCIL (SR-I)14-05-2017

at 1654 hrs

Tripping of 400 kV Vemagiri - Gazuwaka

PGCIL (SR-I) to sort out issues relating to AR functionality

operation for both Main-CB and Tie-CB at both Vemagiri and

Gajuwaka substations

by PGCIL (SR-I)

End-to-end communication for DT permissive amp other signals

Healthiness of PLCC system components (hardware and software)

repaired replaced

Y-phase to earth fault Auto-reclose was not

successful due to persistent fault Vemagiri end had

sent a Direct Trip after un-successful Auto-reclose

AR attempt was observed in Gazuwaka end DR

after 3 phase trip

65III10

Yet to be informed PendingPole-1 got tripped due to failure of auxiliary supply

changeover 400kV Jeypore-Gazuwaka line-2 got

tripped on operation of over-voltage protection

Pole-2 east shunt reactor got failed and this in turn

resulted in tripping of HVDC pole-2 due to Pole-2 Y

block activation 400kV Jeypore-Gazuwaka line -1

also got tripped during the incident

28-Apr-17 Pole-

1 at 844 hrs

and Pole-2 at

907 hrs

Tripping of HVDC Gajuwaka Pole-1amp2

and 400 kV Jeypore-Gazuwaka line-1amp2

PGCIL (SR-I)1 PGCIL (SR-I) to provide fully automatic supply-changeover

scheme for Pole-1 auxiliaries at the earliest

2PGCIL (SR-I) to furnish a detailed report on the reasons for East

Shunt Reactor failure including remedial action taken OEM report in

this regard also shall be shared

3PGCIL (SR-I) to provide redundant AC auxiliary supply to both

Pole-1 amp Pole-2 either by making use of tertiary of ICT-1 or from

external dedicated feeder

Annexure-III

58II3 (GI) Tripping of 400 kV Sriperambudur-

SVChatram line

14-08-2016 at

1349 hrs

Line tripped at Sriperambudur end only on

operation of directional earth fault protection

(i) PGCIL (SR-II) to disable high-set of line DEFRrsquos and

(ii) PGCIL (SR-II) to block line DEFR operation when DPR is in active

condition (has picked up) at their Sriperambudur SS

58II5 (GI) Tripping of 400 kV Neyveli TS2-Pugalur

line and 400 kV Neyveli TS2-Neyveli TS2

EXP line

21-08-2016 at

1035 hrs

Failure of Y-Ph tension insulator of tie feeder bay at

Neyveli TS2 Neyveli-Pugalur line tripped due to over

voltage at Neyveli TS2 and direct trip was received

at Pugalur

PGCIL (SR-II) to check the operation of the DPR relays at Pugalur

end NLC TS2 - Pugalur line by trans-playing the event on another

healthy relay and take suitable action including replacement of the

relay accordingly

58II19 (GI) Tripping of 400 kV Madurai-Karaikudi

15-09-2016 at

0302hrs

Line tripped on operation of OVR Stage-I protection

at Karaikudi and Direct Trip was received at Madurai

PGCIL (SR-II) to check the operation of OVR relays at their 400 kV

Karaikudi SS and properly configure linesrsquo DRs amp ELs so that events

pertaining to OVR (Stage-I amp Stage-II) protection operation (START

amp TRIP) get explicitly recorded

59II20 (GI) Tripping of HVDC Talcher-Kolar pole-1 10-10-2016 at

1635 hrs

Pole-1 of HVDC Talcher-Kolar tripped due to receipt

of lsquorsquoPole block command from Talcher end due to

tripping Pole-1 DC filter at Talchar end Pole 2 went

into metallic return mode after tripping of pole-1

PGCIL (SR-II) to check the correctness of non-operation of SPS

(Talcher ndashKolar Trip Signal-1) in the instant case by comparing it

with the incident of tripping of HVDC Talcher-Kolar pole-1 on

05102016 and furnish a report on it to PCSC forum

59II24 (GI) Tripping of 400220kV ICT-2 at

Somanahalli SS

24-10-2016 at

354 hrs

ICT-2 tripped on operation of Buchholz relay PGCIL (SR-II) to properly configure ICT protection relay DR so that

digital signals are recorded with proper names at their 400220 kV

Somanahalli SS

59III4 Tripping of 400 kV Salem -Udumalpet line-2

13-10-2016 at 0306 hrs

Line tripped on R-phase to earth fault Line auto-reclosed at Udumalpet end and did not reclose at

Line tripped on R-phase to earth fault Line auto-reclosed at Udumalpet end and did not reclose at Salem

62II6 Tripping of 400 kV Trichy-Karaikudi line 21-01-2017 at 2145 hrs

Line tripped on operation of over voltage protection at Karaikudi end and direct trip was received at Trichy Voltage recorded in DR in antecedent

conditions were 2454 kV 2432 kV 2536 kV

respectively

1 PGCIL (SR-II) to ensure OVR settings adopted for 400 kV lines at Karaikudi SS are as per SRPC provided settings with a drop-off to pick-up ratio gt 097

2 PGCIL (SR-II) to configure OVR_START event in the corresponding Relay BCU Event Logger for all 400 kV lines emanating from their

Karaikudi SS

62III5 Tripping of 400 kV Tumkur ndash Bidadi line 17-02-2017

at 1044 hrs

B-E fault Line did not auto-reclose 1 PGCIL (SR-II) to properly configure AR logic operation at Bidadi

end and ensure itrsquos correct operation for a fault during reclaim time

2 PGCIL (SR-II) to ensure time-sync of protection relays with GPS at

both Tumkur and Bidadi substations

at 1036 hrs

B-E fault Line did not auto-reclose PGCIL (SR-II) to properly configure AR logic operation at Bidadi

62V1 Tripping of 400kV Vallur-Kalivandapattu

line-2

22-02-2017 at

455 hrs

Line tripped due to failure of R phase jumper Two

faults observed from DR 2nd fault cleared in 500ms

from Kalavindapattu end

PGCIL (SR-II) to enable Trip on Reclose (TOR) at Kalavindapattu end

on all 400 kV lines emanating from it

57II2 Tripping of 400 kV Mywady-Salem line-1

and 400 kV Mywady-Madurai line

PGCIL (SR-II) Yet to be informed03-07-2016 at

0306 hrs

400kV Mywady- Madurai line tripped on a Y-phase

to earth fault due to agriculture fire Tie-CB LBB

relay got operated at Mywady end and resulted in

tripping of Main breakers of 400kV Mywady-

Madurai and 400kV Mywady-Salem line-1 which are

in the same diameter

PGCIL (SR-II) to furnish a report on the remedial action taken after

ascertaining the reasons for (i) non-opening of Main-CB of Mywady

ndash Madurai line at Mywady end on Tie-CB LBB operation and (ii)

delay in sending DT to the remote ends after Tie-CB LBB operation

Pending

Annexure-III

65II2 Tripping of 400 kV Kudgi (PG) - Tumkur

line-2 and Kudgi (PG) ndash Kudgi (NTPC)

line-1

06-05-2017 Kudgi (NTPC) feeder tripped at Kudgi (PG) end on

operation of distance protection R-N Zone-1

Tumkur feeder tripped at Kudgi(PG) end on

operation of NGR buchholtz relay

1 PGCIL (SR-II) to sort out AR related issues at Kudgi (PG) end on

400 kV Kudgi (PG) ndash Kudgi (NTPC) lines and put AR into service

2 PGCIL (SR-II) investigate reasons for NGR Buccholtz trip on 400

kV Kudgi (PG) ndash Tumkur line-2 and furnish action taken report wrt

rectifying the same

58II16 (GI) Multiple tripping at 400 kV Kalpaka SS 06-09-2016 at

1643 Hrs

Y-Pole breaker of Bus reactor-3 got failed during its

charging This resulted in a bus fault in 400kV bus-1

resulting in tripping of 400kV elements connected to

PGCIL (SR-I) amp PGCIL (SR-II) to review their Reverse Zone settings of

distance relays so as to bring them in line with Ramakrishna

Committee guidelines at all their substations in the southern

region

PGCIL (SR-I) amp PGCIL

(SR-II)

51II4 NTECLTripping of 400kV Alamathy-Tiruvalam

line-1 and 400kV Alamathy-Vallur line-2

NTECL Vallur to furnish a report detailing the reasons for mal-

operation of Vallur end relays for a fault on Alamathy-Tiruvalam line-

1 and remedial measures taken to PCSC forum In the report their

preparedness for implementing line differential protection on Vallur-

Alamathy lines may also be indicated

400kV Vallur-Alamathy Line-2 got tripped from

Vallur end during failure of Y-phase LA in 400kV

Alamathy-Tiruvalam line Protection at Vallur end

tried for an auto-reclose and gave a 3 phase trip

3Ф Trip at 400kV Alamathy end due to DT received from vallur end for

BФ LAS bursted in Alamathy -Thiruvalam - 1 at Alamathy end

Mail received on 27-04-2016 and 20-05-2016

BФ LAS bursted in Alamathy -Thiruvalam - Line-1 at Alamathy end

Pending13-12-2015 at

2242 hrs

Others

Annexure-III

56III5 Tripping of 400 kV Neyveli TS-2-

Pugalur line

04-06-2016 at

1636 hrs

B phase to earth fault occurred in line Auto-reclose

had not operated at NLC TS-2 and DT was sent to

Pugalur end resulting in a 3 phase trip

NLC to review the necessity of providing Relay Definitive Trip and

accordingly take steps to disable it on all lines emanating from their

generating stations

NLC Direct trip triggering of DR wii be carried out at TS2 end during the next

planned shutdown of the Pugalur Ts2 feeder

Direct trip triggering of DR carried out at TS2 end for the TS2-Pugalur

feeder on 25-01-17

Pending

56II16 Tripping of 400 kV Gajwel-Singareni

line-2

30062016 at

2343 hrs

Tripped on 3-phase Trip at Gajwel end SCCL to configure Jaipur end relay‟s EL properly so that the time-

stamp resolution is extended downwards up to milli-second level

SCCL Yet to be informed Pending

1Singareni TPS to furnish single line diagram of their switchyard

along with the Over Voltage Relay settings adopted for various

transmission lines and to ensure that they are in line with the SRPC

provided gradings

2Singareni TPS to upload various tripping files (FIRDRELTR)

pertaining to a tripping event involving their station in SRLDC web-

portal within 24-hrs of occurrence of that event in compliance of

IEGC Regulation 52(r)

Line tripped on operation of Over-Voltage

protection at Singareni and Direct Trip was received

at Gajwel DR amp EL of Singareni was not furnished

59III3

57II8 NTPC (Ramagundam)

10-07-2016 at

156 hrs

Line tripped at Ramagundam end on operation of over-

voltage protection Dichipally end tripped due to

receipt of Direct Trip signal

1NTPC-Ramagundam to ensure correctness of operation of Over

Voltage relays by taking remedial measures like maintaining

healthiness of concerned CVT‟s setting drop-off to pick-up ratio at

097 amp above etc

2NTPC-Ramagundam to ensure time sync of their station‟s DR amp

EL with GPS

3NTPC-Ramagundam to sort out analog values indication amp

overlapping issue of time-stamp in their station DR‟s

4NTPC-Ramagundam to properly configure their EL‟s so that events

are recorded with msec resolution

Line tripped on B-phase to earth fault Line auto

reclosed at Chandrapur end and did not reclose at

Ramagundam

16-07-2016 at

438 hrs

Tripping of 400 kV Ramagundam -

Chandrapur line -2

1NTPC-Ramagundam to furnish remedial measures taken wrt AR

non-operation and unwarranted DT sending to other end

2NTPC-Ramagundam to configure protection relays DR‟s such that

events get recorded for at leas

2000 msec post-triggering so as to cover complete AR operation

Dichipally line

NTPC-Ramagundam mail dated 09032017

1 Main-II relay replaced Over voltage relays pickup to reset ratio is 098

--- Completed

2 DR and EL are time synchronized with GPS clock

-------- Completed

3DR alalog overlaping issue is sloved ---- Completed

4 ----- Pending

Yet to be informed

Pending

Tripping of 400 kV Gajwel-Singareni line-

02-04-2016 at

1708 hrs 1MAPS to furnish a detailed report on the tripping of SP Koil ndash

MAPS lines 1 amp 2 at MAPS end with focus on the correctness of the

settings of Main-I amp Main-II relays (for primary amp back-up

protections) on both the lines

2MAPS to take steps to provide down-loading facility for DR amp EL

from Main-I amp Main-II relays on all 230 kV lines emanating from

3MAPS in co-ordination with SP Koil to carry out PLCC end-to-

end testing on SP Koil ndash MAPS lines 1 amp 2 and ensure healthiness

of PLCC communication amp carrier-aided protection

4MAPS to put in service Auto-Reclosure feature on all four 230 kV

lines emanating from MAPS by June 2016

Pending

Complete outage of 230 kV SPKoil

Station of TANTRANSCO

B-phase CT failure occurred in 230 kV SPKoil -

MAPS line-1 Busbar protection got operated at

SPKoil station All elements except 230kV

Oragadam and 230kV Kalivandapattu got tripped at

230kV SPKoil station bdquoY‟ phase CT and support

insulators also got damaged

27-09-2016 at

0101 hrs

Status revided vide MAPS mail dated 06122016

1 The settings given by Ms TANTRANSCO were adopted for Main ndashI amp

Main- II relays for both the lines The same settings were verified to be

same Subsequently calibrated was done and no drift was observed

--- Complied

2 From May 2016 onwards the DR EL and trip report are being sent by

mail to SRLDC Bengaluru by MAPS

--- Complied

3 Monthly maintenance of PLCC equipments is being done by Ms

TANTRANSCO At present PLCC telephone is not working it is being

followed up

--- Complied

4 CVTs are planned to be procured from Ms TANTRANSCO by the end

of February 2017 and AR will be implemented for all the lines emanating

from MAPS by July-2017 as discussed in the current SRPC meeting on

25112016

--- Pending

PendingNPCIL (MAPS)

1 The relay will be checked in next opportunity if required it will be

changed with new one------------- Pending

2DR time recording increased to 2 sec --------- Completed

NTPC Pending

Annexure-III

62III2 Tripping of 400 kV Kaiga-Guttur line-1 06-02-2017

at 0501 hrs

B-phase to earth fault Line did not auto-reclose at

Kaiga end

1 KGS to properly configure all relays DR‟s time scale for a post-

triggering period of 2 sec to capture events such as complete AR

operation

2 KGS to ensure time-synchronization of all protection relays with

GPS in their 400 kV switchyard

NPCIL (KGS) Yet to be informed Pending

63III4 Tripping of 400 kV Gajwel-Singareni line-

07-03-2017 at

1652 hrs

Line tripped on B-phase to earth fault Line did not

auto-reclose

1 SCCL to properly configure LBB logic for all line relays

where AR has been put into service for 1-ph initiation based

on phase segregation (ie for the faulted phase) at their

Singareni TPS

64II8 Tripping of 400 kV Tirunelveli-

Kudankulam line-3

23-04-2017 at

0556hrs

R-phase to earth fault had occurred in Tirunelveli -

Udumalpet line-2 During the incident Tie-CB LBB

got operated at Tirunelveli end due to sluggish

operation and tripped 400 kV Tirunelveli -

Kudankulam line-3

NPCIL (KKNPP) to configure DRrsquos amp ELrsquos of protection relays at their

station for recording DT receipt event at their Kudankulam NPP

NPCIL(KKNP) Yet to be informed Pending

Yet to be informed63III8 NPCIL (KGS)Tripping of 400kV Kaiga-Guttur line-2 Line tripped on Y-phase to earth fault Line auto-

reclosed from Guttur end and failed to re-close from

Kaiga end

1 NPCIL (KGS) to furnish an action taken report on the

reasons for AR lock-out and remedial action taken to rectify

the same

2 NPCIL (KGS) to configure DR‟s of line protection relays for

a post triggering period of 2 sec to capture complete AR

operation at their Kaiga GS

3NPCIL (KGS) to furnish FIR amp TR for tripping events as

per SRLDC provided formats

27-03-2017 at

706 hrs

Pending

Annexure-III

01-01-2015 at

1338 hrs

42II18 400kV Raichur TPS-Raichur(PG) line-

1amp2 400kV Raichur-Mahboobnagar

Unit7 and ICT-2 at RTPS tripped

during the incident B phase to earth

fault had occurred in 400kV Raichur

TPS-Raichur line-1

1 Bus bar protection shall be provided by asset owner ( ie

KPTCL)

2 Settings for main distance protection amp Overcurrent protection

shall be examined and reviewed

3 Time synchronization of the Substation shall be ensured

As reported directional over current relay of ICTrsquos

operated due to snapping of line jumper in 220kV

Lingapur line

1 KPCL to review REF setting (DMT or IDMTL) for unit-7 by first

week of April 2015 and inform the same to PCSC forum

2 TSTRANSCO to furnish Mehaboobnagar‟s DR and EL and the

reasons for distance relay operation at their end within a week‟s time

3 PGCIL (SR-I) to rectify the issues relating to AR operation relay

reach (Z2) reverse reach (Z4) and SOTF auxiliary contacts within a

week‟s time and submit the actions taken to PCSC forum

16-07-2014400220 kV ICT-1 amp 2 at

MUNIRABAD

On account of R-phase to earth fault line tripped at

Hassan end due to operation of distance Zone-2 and

non-receipt of carrier From DR of Talaguppa end it

is observed that fault had occurred in Yphase

09-03-2015 at

0636 hrs

Tripping of 400

kV TALAGUPPA

ndash HASSAN line

Multiple tripping at Raichur TPS of

Miscellaneous

1 PGCIL and KPTCL to ascertain the reason for the phase

discrepancy in the relay operation and take suitable remedial

measures

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

the report to the PCSC forum

1 Yet to be informed by KPCL ---- Pending

2 Mail received on 26-05-2015 from TSTRANSCO

It is found that the main-2 ABB make REL316 type distance relay was

defective and same was replaced with MICOM P444 by MsPGCIL on

2304-2015 After replacement of main-II DR can be extracted from this

relay For EL in to service some field winding is pending which is being

taken up in this month -- Complied with

PGCIL mail recieved on 27-04-2016

End to end PLCC tunning carried out

PGCIL (SR-I) RVMD 14072016

Relay settings of all the stations in SRTS-1 were derived as per

Ramakrishna Commettee recomendations and implemented - Complied

TSTRANSCO

PGCIL (SR-I)

PGCIL (SR-II) KPTCL

PGCIL (SR-I)

End to end testing of PLCC has been done and problem in the PLCC is

atttended

Mail received on 27-05-2015 (KPTCL) amp 29-07-2015

atttended Phase discrepancy in the relay operation is to be checked jointly

Mail recieved on 02-09-2015 from PGCIL (SR-II)

Problem is in identification of phases at Talguppa end To be rectified by

Ms KPTCL

Mail recieved on 28-06-2016 from KPTCL

The matter is reffered to the concerned Operation and maintance wing to

set right the mismatch of phases in 400kV Talaguppa-Nelamangala and

Talaguppa-Shantigrma lines at Talaguppa in cordination with PGCIL

Pending

(with KPTCL)

Mail recieved on 27-05-2015 (KPTCL)

1 KPTCL has taken action to provide bus bar protection to 220kV buses

2 Over current relay Settings of ICTs to be reviewed by PGCIL

Mail received on 29-07-2015 (KPTCL)

Initial Tendering stage

Detailed estimate prepared for taking up the work CEE Transmission

Zone Gulbarga will take up necessary procurement and further execution

----------------------------------------------------------------------

1 Pending from KPTCL side

2 Complied with as per PGCIL (SR-I) RVMD 14072016 which stated

that Relay settings of all the stations in SRTS-1 were derived as per

Ramakrishna Commettee recomendations and implemented

Pending (with

Pending

(with KPTCL)

Annexure-III

Tripping of Unit 1 at NCTPS 24-05-2015

at 1913 hrs

ID Fan trip

Tripping of Unit 1 at MEPL 24-05-2015

at 1913 hrs

Coal Mill tripped

Tripping of Unit 1 at

Krishnapatnam

24-05-2015

at 1917 hrs

Generator Protection operated

Tripping of Unit-8 at RTPS 24-05-2015

at 1919 hrs

Tripped on Overvoltage

1 All Tripped units viz Krishnapatinam MEPL Raichur NCTPS

to submit a detailed report on this event including the remedial

measures taken to PCSC forum

2 KPCL to check the excitation system of Unit 8 of RTPS and

submit the remedial measures taken to PCSC forum

KPCL MEPL

APGENCO TNEB

As per FIR submitted CT damage observed in

Chitoor-Main bay (404) Main breakers connected to

bus-1 (401 404 407 410) got tripped on operation of

bus bar protection Unit-1 tripped on operation of

MFT Unit-2 was not in service

Complete outage of Krishnapatnam TPS

Pending (with

APGENCO letter dated 18032016

1SOE and SLD are attached The DR of 405 CB is not generated during

the incident Now the problem is identified and rectified

--------- Completed

2All the 3 lines ie CHTR-2 MNBL-I amp II tripped in zone

protection The fault was in Blind zone ie P2 side of CT where it was

covered under Bus fault by the time fault moved on to P1 side when the

fault comes under STUBTEED zone after 330msec all the feeders expect

CHTR-1 tripped in Zone-II and total fault persisted for 500msec before the

405 TIE CB opens and clear the fault As a remedial the STUB protection

operation also checked and found OK-------Completed

3The Time Sync was missed on the day and found there was problem with

LAN Timer same was rectified Now found OK

-----------Completed

4Now the DR Time scale changed to 1 sec for Pre fault and 3 sec for Post

fault and STATE of events are corrected wherever found wrongor

misguiding during analysis---------Completed

PGCIL-SR1 RVMD 27-04-2016

Procurement of differential protection for 400kV NPS-NLR DC and

400kV RCR-RTPS-DC is under tendering

The proposal for procurement of Line differential Protections for 400kV

Raichur - RTPS-1 amp 2 and 400kV Nellore - NPS - 1 amp 2 lines has been

approved and tender is under technical evaluation

Pending with

PGCIL(SR-I)

08-09-2015 at

1820 hrs

1 APGENCO to furnish to PCSC forum (i) A3-size Single Line

Diagram of SDSTPS and (ii) the sequence of events with time stamp

showing the protection that opened Tie-CB (405) at SDSTPS

2 APGENCO to review STUBTEED protection in all dias at

SDSTPS and ensure that they are configured for instantaneous

operation

3 APGENCO to properly configure the STATE of the tripping events

so that they get recorded appropriately like TRIP OPERATED in

their corresponding Event Loggers

4 APGENCO to ensure time sync of all DR‟s and EL‟s at SDSTPS

5 PGCIL (SR-I) to provide line differential protection for 400 kV

NPS ndashNellore-PG lines 1 amp 2

TANGEDCO vide their mail dated 07072015 informed that as per the

discussion and recommendation of 44th meeting of PCSC held on

28052015 a time delay of 2 Sec had been introduced for the above

tripping for all the ID fans at NCTPS-II

MEPL vide their mail dated 14092015 informed that they had

implemented 2 seconds delay for under voltage tripping of all Drag Chain

Feeder Conveyors And this has been done for both the Units

The unit not tripped on Generator protection but tripped on Economiser

inlet flow protection consequent to tripping of TDBFP on lube oil pressure

lowBefore tripping dip in voltage was observed in the LT system which

caused tripping od lube oil pumpsAfter the incidentChangeover scheme

on under voltage of LT System was reduced from 80 with 2 sec delay to

40 with 200msec delay

APGENCO PGCIL (SR-

Annexure-III

12-11-2015 at

0020 hrs

Tripping of 400kV Gooty-Nelamangala

KPTCL KPCL NPCIL

(KAPS)

1 KPTCL KPCL to see the possibility of implementing Weak Infeed

logic with Echo feature enabled by Under

Voltage (27) element on Kadra-Karwar lines 1 amp2 and implement

the same if feasible

2 NPCIL to time-coordinate Kaiga‟s DEFR settings with (i) Zone-2

settings at Kaiga and (ii) primary protections of the lines emanating

from Kadra and Kodasalli

3 KPCL to ensure time-sync of EL‟s and healthiness of the Fault

Locators at Kadra

220kV Kadra-Karwar lines-1amp2 tripped

on earth fault in B-phase in zone-2

Kaiga-Kadra line tripped at Kaiga end

only on operation of directional eath

fault protection

31-07-2015 at

1144 hrs

Tripping of 220kV Kadra-Karwar lines -

1amp2 and 220kV Kaiga-Kadra line

PGCIL (SR-I) mail received on 27-04-2016

1 The firmware of REL670 is being upgraded ------- Completed

2 The recording of events in msec interval is being taken up with OEM

Henceforth for analysis purpose we will provide larm list which has msec

time stamp -------- Completed

3 End to end testing of PLCC code transmision and tuning of channels

carried out ------- Completed

4 Procurement of differential protection for 400kV NPS-NLR DC and

400kV RCR-RTPS-DC is under tendering The legends modified in

Eventalarm list Provision of diff relay for all short lines emanating from

NPS is being taken up with our corporate -------- Pending

PGCIL(SR-I) RVMD 14-07-2016

PGCIL RVMD 27042016

AR blocked due to failure of PLCC link The defective PLCCcards

replaced at Neelamgala end

PGCIL RVMD 14072016

replaced at Neelamgala end End to end testing of PLCC carried out and

PLCC link is healthy ------ Pending

2 Gooty end Time syc unit is replaced with new one and commissioned ---

----- Completed

3 Yet to be informed by KPTCL --- Pending

PGCIL (SR-I) KPTCL 1 For Gooty ndashNelamangala line PGCIL (SR-I) and KPTCL to

provide 3-ph trip logic at their respective ends upon detection of

PLCC link failure during dead-time of AR operation

2 PGCIL (SR-I) to make GPS functional at Gooty SS and ensure

time-sync of various DR‟s and EL‟s with it (GPS)

3 PGCIL (SR-I) KPTCL to furnish reason for the operation of

Backup impedance protection of the line reactor at Nelamangala end

and the remedial measures taken to PCSC forum

Pending (with

KPTCL)

1PGCIL (SR-I) to furnish Action Taken Report on the findings of

OEM on relay mal-operation at NPS end on 400 kV NPS ndash NCCK

line to PCSC forum

2 PGCIL (SR-I) to appropriately configure Station Event Logger at

NPS to record events at msec interval

3 PGCIL (SR-I) to carry out PLCC end-to-end testing in coordination

with TPCIL for 400 kV NPS ndashTPCIL line

4PGCIL (SR-I) MEPL SEL TPCIL amp NCC to take steps to

provide line differential protection at their respective ends on all 400

kV lines (except Gooty line) emanating from Nellore Pooling Station

and furnish an action plan to implement the same

Pending

Availability of week end infeed with eco feature to be confirmed by

SEERTCHubli --- Pending

Mail recieved on 03-12-2016 from NPCIL(KGS)

The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga

Kodasally lines were disabled IDMT DEFR is retained The 200 ms

Definite time back up oc element in both Kaiga Kadra and Kaiga

Kodasally lines were disabled IDMT is retained

------ Completed

3 Yet to be informed by KPCL

1 Since PT blasted (B phase) at Karwar end resistive over reach occurred

hence Backup protecion operated at Kadra end (zone-2 not sensed) ---

Pending

3Newly commissioned micom P444 relay time synchronised with GPS

------ Completed

Running units at Thermal Powertech power Station

tripped due to tripping of 400kV Nellore pooling

station (NPS)-TPCIL line and 400kV Nellore pooling

station (NPS)-ECC line

30-12-2015 at

0602hrs

R-phase to earth fault had occurred in Line Line did

not auto-reclose from both ends It was mentioned that

YampB pole breakers at Neelamangala tripped on

operation of pole discrepancy and backup impedence

protection for line reactor got operated

Complete outage of TPCIL power station 50I2

PGCIL (SR-I)

MEPL SEL TPCIL

Pending

Annexure-III

52I8 Complete outage of 400kV NTPL station

and CEPL Stations

14-03-2016 at

0136 hrs

Running Units at NTPL and Coastal Energen power

station got tripped due to tripping of evacuating lines

NTPL and PGCIL (SR-II) to furnish compliance report of the

recommendations given by PSAG-15 Committee that held its meeting

on 12-13 April 2016 at NTPL Tuticorin

PGCIL (SR-II)

NTPL mail received on 19052016

All General Recommendations will be done in the second week of June

2016 ---------- Complied by NTPL

Yet to be informed by PGCIL (SR-II)

Pending

[with PGCIL

(SR-II)]

56III4 Tripping of 220 kV Sedam-Tandur line 03-06-2016 at

2152 hrs

Line tripped on B-phase to earth fault Auto-reclose is

not enabled for line

KPTCL and TSTRANSCO to fast-track providing AR on 220 kV

Sedam ndash Tandur line and furnish an action plan of providing the same

by next PCSC meeting (PCSC-57)

TSTRANSCO

KPTCL and TSTRANSCO to take steps to provide AR feature on

220 kV Sedam ndash Tandur inter-state line at their respective ends at the

earliest

TSTRANSCO

PGCIL mail received on 27-04-2016

Being pursued with APTRANSCO

AS maintenance being carrired out by PGCIL(SR-1) the required relay

replacement (wiringprogramming) may also be carried out by PGCIL(SR-

PGCIL RVMD 14072016

1 The CB problem has been attended by POWERGRID by using OEM

Ms BHEL services amp POWERGRIDs OampM spares

------ Completed

2 Being pursued with APTRANSCO to replace the faulty Event Logger at

Vijayawada (Nunna) SS -------- Pending

APTRANSCO mail dated on 31-08-2016 amp 04032017 amp 24052017

As maintenance being carrired out by PGCIL(SR-1) the required relay

PGCIL (SR-I)

APTRANSCO

1 PGCIL (SR-I) in co-ordination with APTRANSCO to address

the problem with CB at the earliest opportune time

2 APTRANSCO to take steps to replace the faulty Event Logger at

Vijayawada (Nunna) SS

Line tripped at Mamidipally end only on Direct Trip

receipt from Ghanapur end

30-04-2016 at

1640 hrs

Line tripped due to operation of over voltage

protection at Vijayawada end and Direct Trip was

received at Sattenapalli end

25-12-2015 at

301 hrs

Tripped on 3-phase Trip at Gajwel end30062016 at

2343 hrs

19-06-2016 at

1527hrs

54IV2 Tripping of 400kV Ghanapur-

Mamidapalli line

56II16

Tripping of 400kV Sattenapalli-

Vijayawada line

Tripping of 400 kV Gajwel-Singareni

line-2

Substation of KPTCL

Pending

PendingFor the line under consideration the following shall be carried out by

TSTRANSCO and PGCL (SR-I) in co-ordination

iEnd-to-end communication for DT permissive amp other signals may

iiHealthiness of PLCC system components (hardware and software)

replaced

PGCIL (SR-I)

TSTRANSCO

Yet to be informed

Pending

1TSTRANSCO and SCCL to check drop-off to pick-up ratio of OV

relay and ensure that it is kept at 097 amp above

2TSTRANSCO and SCCL to configure respective end bdquos DR amp EL

so that they get triggered on OVR protection and record relevant

events

3SCCL to configure Jaipur end relay‟s EL properly so that the time-

TSTRANSCO

Yet to be informed

Pending

Annexure-III

R-phase to earth had occurred in 400kV BTPS-JSWEL

line and protection issued a 3 phase trip

64I1 Complete outage of North Chennai TPS

24-04-2017

at 2102hrs

tripping of Units

Pending

25-04-2017

at 1827hrs

tripping of Unit

64I3 Complete outage of North Chennai TPS STG-2

26-03-2017at 2109 hrs

Tripping of evacuating lines due to fault led to tripping of running Unit at NCTPS Stg-2

64III2 Tripping of 400 kV Ghanapur-

Mamidapalli line

04-04-2017 at

1901hrs

B-phase to earth fault Line auto-reclosed from

Mamidapalli end and tripped from Ghanapur

For the line under consideration PGCIL (SR-I) TSTRANSCO to (i)

rectify issues wrt PLCC channels (ii) restore PLCC carrier

communication and (iii) put AR into service at the earliest

PGCIL (SR-I)

TSTRANSCO

APGENCO

TSTRANSCO

Direct Trip was received at VTPS and line was

holding from Suryapet end

13-06-2016 at

1655 hrs

56IV2 Tripping of 400 kV VTPS-Suryapet line

57I1 Complete outage of 220 kV Karwar

Substation of KPTCL

12-07-2017 at

1136 hrs

Triggering incident was failure of R phase PT in Bus-

1 at 220kV Karwar substation 220kV Kaiga-

Kodasalli tripped during the incident Also bus shut

down occurred at Kadra and Kodasally stations

1NPCIL (KAPS) to disable DefiniteTime OC relay and put in its

place by IDMT OC relay for backup protection on both 220 kV

Kaiga ndash Kadra line and 220 kV Kaiga ndash Kodasalli line at Kaiga end

2KPTCL to put bus bar protection in service at their 220 kV Karwar

SS at the earliest

3KPCL KPTCL to implement Weak In-feed Logic with Echo

feature enabled by Under Voltage (27) element on Kadra ndash Karwar

lines 1 amp 2

KPTCL KPCL NPCIL

(KAPS)

NPCIL(KGS) mail dated on 03-12-2016

AThe 200 ms Definite time DEFR element in both Kaiga Kadra and

Kaiga Kodasally lines were disabled IDMT DEFR is retained

B The 200 ms Definite time back up oc element in both Kaiga Kadra and

Kaiga Kodasally lines were disabled IDMT is retained

------Completed

Issue was addressed to the concerned for necessary action

Meeting was conducted and the relays procurement for all the locations is

under progress

Pending57II9 Tripping of 400 kV Nellore (PG) - NPS

MEPL line

18-07-2016 at

1905 hrs

from MEPL end

PGCIL (SR-I) TPCIL MEPL SEL SGPL APTRANSCO

APGENCO and SDSTPS to implement line differential protection on

all 400 kV transmission lines (of length less than 50 km) emanating

from Nellore PS Nellore (PG) SS and Nellore (AP) SS [It may be

noted here that the cut-off length of 50 km has been specified with a

view to exclude only long transmission lines]

APGENCO PGCIL(SR-

I) TPCILMEPL

SELSGPL

APTRANSCO

Pending

63II9 KPCLJSWEL Yet to be informed Pending

1 TANTRANSCO and PGCIL (SR-II) to take steps to complete

insulator replacement works on the 400 kV lines owned by them in

Chennai area within 3 months

1 JSWEL to follow file naming terminology provided by SRPC

for various tripping files uploaded in SRLDCrsquos TMS portal

2JSWEL to furnish reasons for AR-BLOCK observed during

the instant tripping and remedial action taken by them to

keep AR in service

3 KPCL to configure DR amp EL properly to record OVR Stage-I

amp Stage-II protections at their BTPS station

14-03-2017 at

1911 hrs

Tripping of 400 kV YTPS-BTPS line and

400 kV BTPS-JSWEL line

Status received vide TANTRANSCO mail dated 15-06-2017

1 All the Porcelain insulators of 400kV NCTPS-II - Vallur feeders-1amp2

were replaced with Polymer insulators by 20052017

2 Existing Porcelain insulators of all other 400kV feeders are being

replaced with Polymer insulators in a phased manner

TANTRANSCO

PGCIL(SR-II)

APGENCO in coordination with TSTRANSCO

1End-to-end communication for DT permissive amp other signals may

2Healthiness of PLCC system components (hardware and software)

replaced

PendingYet to be informed

Annexure-III

65II5 Tripping of 400 kV Ghanapur-

Mamidapalli line

08-05-2017 at

1915 hrs

Line tripped at Ghanapur end only and was holding

from Mamidapalli Ghanapur end protection had

sensed R-phase to earth fault

by TSTRANSCO in coordination with PGCIL (SR-I)

1 End-to-end communication for DT permissive amp other signals

2 Healthiness of PLCC system components (hardware and

software) at both ends shall be checked and faulty components

shall be repaired replaced

TSTRANSCO PGCIL

(SR-I)

65III12 Tripping of 400 kV Srisailam-Dindi line-2 24-05-2017

at 1502 hrs

R-phase to earth fault Auto-reclose was successful

at Dindi and Zone - 1 3-phase trip at Srisailam

Since all 400 kV lnies emanating from Srisailam LB are composite

feeders APTRANSCO TSTRANSCO can keep AR functionality disabled at respective remote end stations under their control

APTRANSCO TSTRANSCO Yet to be informed Pending

Yet to be informed PendingTriggering incident was failure of CT in 110 kV

Villianur-Kurumbapet at Villianur substation 230KV

Villianur ndash NLC2 and 230 kV Villianur - Pondy lines

got tripped from Pondy end (on operation of DEF)

and NLC end (on operation of Zone-3) respectively

resulting in loss of supply to 230 kV Villianur

substation

65I2 Complete outage of 400kV Uravakonda

and Jammalamadugu Substations

31-05-2017 at

1744 hrs

Triggering incident was tripping of 400 kV Kurnool-

PG - Narnoor line - 1 amp 2 and 400 kV Narnoor-

Jamalamadugu line-2 which led to loss of supply to

400kV Uravakonda and Jamalamadugu 400kV Gooty-

Narnoor 400kV Narnoor-Jamalamadugu-1 400kV

Srisailam-Narnoor 400kV Uruvakonda-

Mahboobnagar-1amp2 were out of service in

antecedent condition

1 For 400 kV Ghani ndashNarnoor line the following shall be carried out

by APTRANSCO

(ii) Healthiness of PLCC system components (hardware and

2 PGCIL (SR-II) to take appropriate action wrt disabling non-

directional instantaneous Igt4 protection that operates without

checking existence of stub If required the issue may be referred to

relays OEM for appropriate solution or the present relays may be

replaced with other relays with different styles that donrsquot have the

issue observed

APTRANSCO PGCIL

(SR-II)

1 PED to furnish an action taken report wrt complying with the

protection audit recommendations

2 PGCIL (SR-II) to review Zone-3 and DEF protection setting at

Pondicherry end 230 kV Pondicherry ndash Villianur and 230 kV

Pondicherry ndash Bahour line and set them appropriately to achieve

required time-coordination with OC protections of ICTrsquos at Villianur

3 NLCIL to keep DEF protection in blocked condition as long as

Distance Protection is active and configure it to become active only

when distance protection does not pickup to avoid time-

coordination issues

19-05-2017 at

1235 hrs

Complete outage of 230 kV Villianur

Substation of Pondicherry

65I1 PED PGCIL (SR-II)

by TANTRANSCO in coordination with PGCIL (SR-II)

PGCIL (SR-II)

TANTRANSCO

by NLCIL in coordination with PGCIL (SR-II)1 End-to-end communication for DT permissive amp other signals may be ensured by testing at both the ends

2 Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components

Y-phase to earth fault Neyveli TS2 end relay issued

a 3-phase trip 220ms after issue of Y phase trip Direct Trip was sent to Pugalur end preventing auto-reclose

07-05-2017

at 1955 hrs

Tripping of 400 kV Neyveli TS2-Pugalur

65III6 PGCIL (SR-II) NLCIL Yet to be informed Pending

by TSTRANSCO in coordination with NTPC-Ramagundam1 End-to-end communication for DT permissive amp other signals may be ensured by testing at both the ends

software) at both ends shall be checked and faulty components shall be repaired replaced

Over Voltage Stage-1 had operated at Gajwel end

Ramagundam end did not trip as Direct Trip was not received from Gajwel end

29-05-2017

at 0007 hrs

Gajwel line

65II19 TSTRANSCO NTPC

(Ramagundam)

65II16 Tripping of 400 kV Kayathar-Karaikudi

25-05-2017 at

1552 hrs

R-phase to earth fault had occurred in line There

was Zone-2 3 phase trip operation at Kayathar end

and Zone-1 3 phase trip at Karaikudi end

Annexure-III

SlNo Element NameOutage

datetime

Revival

datetimeReason for Outage Sender Receiver

Remedial Measures Actions taken

1 400 kV KAIGA - GUTTUR 1 27-03-2017153800 27-03-2017164800 RELAY MALOPERATION NPCIL (KGS) KPTCL

At Guttur end DPR operated in Z1 R phase AR

unsucessful due to persistant fault

At Kaiga end DPR operated in Zone-1 RN

fault145km AR attempt is observed from Kaiga

end DR

Reason Transient fault Stood OK after test

charging

NPCIL (KGS)

2 400 kV KHAMMAM - KALPAKKA 1 10-04-2017125800 DISTANCE PROTECTION PGCIL (SR-I) APTRANSCO

PGCIL (SR-I)

Tripped on operation of distance protection Line

belongs to APTARSNCOTSTRANSCO

APTRANSCO TSTRANSCO Momentary fault

3 400 kV KHAMMAM - KALPAKKA 2 11-04-2017115000 11-04-2017175900 Y-N faultPGCIL (SR-I) APTRANSCO

TSTRANSCO

PGCIL (SR-I) Tripped on operation of distance

protection Line belongs to

APTRANSCOTSTRANSCO

4 400 Kv RAICHUR - YTPS 18-04-2017131400 18-04-2017150100 DPR ZONE 1-B-PH FAULT KPCL KPTCL To-be-discussed

5 400220 Kv ICT-3 AT NEELAMANGALA 20-04-2017162100 20-04-2017170100DUE TO HEAVY ARCING AT B-

PH ISOLATORKPTCL To-be-discussed

6 400 Kv VTPS - MALKARAM 1 23-04-2017150500 SOTF OPERATED APGENCO TSTRANSCO

TSTRANSCOTripped at both ends Tripped on R-

phase to ground Zone-1 indications AR acted and

was unsucessful at Malkaram end

APGENCO

Pending Remedial Measures Actions taken

for the Critical Tripping Incidents (as on 25072017)

Annexure-IV

7 400 kV KHAMMAM - MAMIDIPALLY 2 08-05-2017160600 08-05-2017174900 R PHASE TO GROUND FAULT PGCIL (SR-I) TSTRANSCO

PGCIL(SR-I)

belongs to APTARSNCO

TSTRANSCO

Tripped at both ends Tripped on R-phase to

ground Zone-1 indications AR acted and was

unsucessful at Mamidipally end

8 400 kV TALAGUPPA - NEELAMANGALA 09-05-2017163600 Y TO GROUND FAULT KPCL KPTCL To-be-discussed

9 400 kV MUNIRABAD - GUTTUR 20-05-2017064100 20-05-2017211000BUS BAR PROTECTION

OPERATEDPGCIL (SR-I) KPTCL

No abnormality found at Munirabad end and line

was in service

PGCIL (SR-I)

Tripped at Guttur end only and line was holding

from Munirabad end

10 400 kV GUTTUR - HIRIYUR 2 20-05-2017204100BUS BAR PROTECTION

OPERATEDKPTCL PGCIL (SR-II) PGCIL (SR-II) Due to Problem at Guttur end

11 400 kV KAIGA - GUTTUR 2 20-05-2017204100BUS BAR PROTECTION

OPERATEDNPCIL (KGS) KPTCL To-be-discussed

12 400 kV GUTTUR - NARENDRA 2 20-05-2017204100BUS BAR PROTECTION

13 400 kV MUNIRABAD - GUTTUR 20-05-2017160000 20-05-2017170400 B-n fault PGCIL (SR-I) KPTCL

PGCIL (SR-I)

As informed by Guttur Substation line tripped at

Guttur end only without any faciaalarms Line

holding from Munirabad end Suspected mal-

operation at Guttur end

14 400 kV GUTTUR - HIRIYUR 1 20-05-2017204100 20-05-2017211800BUS BAR PROTECTION

OPERATEDKPTCL PGCIL (SR-II)

PGCIL (SR-II) Due to Problem at Guttur end

15 400 kV BTPS-JSW TORANAGALLU 20-05-2017064100 20-05-2017210300BUS BAR PROTECTION

OPERATEDKPCL JSWEL To-be-discussed

16 400 kV KAIGA - GUTTUR 1 20-05-2017204100 20-05-2017213800BUS BAR PROTECTION

17 400 kV GUTTUR - NARENDRA 1 20-05-2017204100 20-05-2017211200BUS BAR PROTECTION

Annexure-IV

18 400220 kV ICT-1 AT HOODY 20-05-2017110700 20-05-2017180500 220KV SIDE WORKS KPTCL To-be-discussed

19 220 kV AMBEWADI - PONDA 1 22-05-2017121100 22-05-2017123000 EARTH FAULT KPTCL GED To-be-discussed

20 400 Kv VTPS - MALKARAM 1 22-05-2017145200 22-05-2017185800 B phase fault APGENCO TSTRANSCO

TSTRANSCOTrippedat both ends Tripped on B-

Phase to ground and Zone-1 indications AR acted

and was unsucessful at Malkaram end

APGENCO

21 220 kV KANIAMPET - KADAKOLA 23-05-2017143200 23-05-2017162400 BREAKER PDR RELAY ACTED KSEB KPTCL To-be-discussed

22 400 kV TALAGUPPA - HASSAN 30-05-2017014600 B PHASE TO GROUND FAULT KPTCL PGCIL (SR-II)

PGCIL(SR-II) Due to persisting fault in KPTCL

portion

23HVDC TALCHER - KOLAR POLE 1 AT

TALCHER01-06-2017232200 02-06-2017001100

DC DIFFERENTIAL

PROTECTION OPERATEDPGCIL (SR-II) PGCIL (ER-I)

PGCIL(SR-II) Due to DC filter Diff relay operation at

Talcher end

24 400 KV NIZAMABAD- DICHPALLY-1 05-06-2017191500 3 PHASE FAULT TSTRANSCO

TSTRANSCOTrippedat both ends Tripped on 3

Phase B-Phase to ground fault and Zone-2

indications at Dichpally end

25 400220 kV ICT-1 AT DICHPALLY 05-06-2017191500 06-06-2017003200 BUCHHOLZ RELAY OPERATED TSTRANSCO

TSTRANSCO 400kv 315MVA ICT-1 at Dichpally

tripped on OSR indications which was a mal

operation of the relay At the same time there was

3 Phase fault in 400kV Dichpally to Nizamabad line

At Nizamabad end(PGCIL) Line Isolator 3 phases

shorted in GIS Module

26400 kV RAMAGUNDAM -

DICHCHIPPALLI05-06-2017191500 05-06-2017223700 3 PHASE FAULT NTPC TSTRANSCO

TSTRANSCO Line did not trip at Dichpally end At

the same time there was 3 Phase fault in 400kV

Dichpally to Nizamabad line for which the line

tripped at Both ends Relay settings need to be

reviewed at NTPC Ramagundam end

NTPC-Ramagundam

27 400 Kv BTPS - YTPS 05-06-2017194800 05-06-2017204400 DISTANCE PROTECTION KPCL To-be-discussed

Annexure-IV

28 400 Kv SATTENAPALLI - SRISAILAM 2 05-06-2017125500 05-06-2017144700 R-n fault APTRANSCO TSGENCO

APTRANSCO

For a momentary fault feeder tripped on R-Ph Z1

indications and AR successful at Sattenapalli end

TSGENCO

Feeder tripped on R-phase to ground Zone-2 at

Srisailam end Due to Feeder consistsing of Under

Ground cable AR was disabled at Srisailam end

29 400220 kV ICT-2 AT KOLAR 06-06-2017191000 06-06-2017223700 DUE TO HEAVY WIND PGCIL (SR-II)

PGCIL (SR-II)

Flashover between 220kV jumper dropper of B

phase and Gantry towards 220kV bus due to heavy

swing of conductor during the unprecedented

heavy winds

30 400 kV KOLAR - HOODY 2 06-06-2017200800 DUE TO HEAVY WIND PGCIL (SR-II) KPTCL

PGCIL (SR-2)

Hand Tripped due to Isolator problem at Hoody

31 400220 kV ICT-2 AT GUTTUR 13-06-2017133000 13-06-2017134500TRIPPED ON EF RELAY

OPERATIONKPTCL To-be-discussed

32400 kV PUGALUR -

KALAIVANTHAPATTU14-06-2017123700 14-06-2017184500 TRIPPED ON Y-N FAULT PGCIL(SR-II) To-be-discussed

33 220 kV KANIAMPET - KADAKOLA 22-06-2017111700 22-06-2017113400EARTH FAULT RELAY

OPERATEDKSEB KPTCL To-be-discussed

35 400 kV KHAMMAM - KALPAKKA 2 03-07-2017092400 03-07-2017104700

DT RECIEVED AT KLPA END

(TRIPPED ONLY AT KLPA

PGCIL (SR-I) APTRANSCO

TSTRANSCO

PGCIL (SR-I)

PLCC belongs to APTRANSCO TSTRANSCO Mal-

operation of PLCC at Kalpaka end Requested

APTRANSCO TSTRANSCO for end to end

testingtunning of PLCC

APTRANSSCO TSTRANSCO

36 400220 kV ICT-1 AT URAVAKONDA 04-07-2017020100 04-07-2017022400MASTER TRIP RELAY

OPERATEDAPTRANSCO To-be-discussed

37 400 kV KAIGA - NARENDRA 2 07-07-2017075000 07-07-2017090800 TRIPPED ON R-Y Ph FAULT NPCIL KPTCL To-be-discussed

Annexure-IV

38 HVDC BHADRAVATHI POLE 1 07-07-2017105900 07-07-2017115400TRIPPED ON NON VALID TAP

CODEPGCIL (SR-I) PGCIL (WR-I)

PGCIL(SR-I)

Tripped due to strucking of OLTC tap during

command execution The same was now working

39 400 kV KHAMMAM - KALPAKKA 2 07-07-2017120300 07-07-2017145000 DT Received PGCIL (SR-I) APTRANSCO

PGCIL(SR-I)

Tripped due to PLCC mal-operation PLCC belongs

to TSTRANSCO APTRANSCO Requested

TSTRANSCO APTRANSCO for end to end testing

tunning of PLCC Khammam end

APTRANSCO

40 400 KV GOOTY - TUMKUR - 1 08-07-2017142200 08-07-2017152600DISTANCE PROTECTION

OPERATEDPGCIL (SR-I) PGCIL (SR-II)

PGCIL(SR-I)

Tripped due to snapping of earth wire while

stringing of OPGW Advised concerned to take

additional precautions while carrying OPGW

stringing

PGCIL(SR-II)

41 400230 Kv ICT-1 AT SVCHATRAM 14-07-2017190300TRIPPED ON RESTRICTED

EARTH FAULTTANTRANSCO

TANTRANSCO

REF protection acted in ICT-1 during Auto Reclose

(AR) attempt of 400kV SVChatram-Alamathy

feeder-2 (through fault condition) As per the relay

manufacturer (GE-T60) guidelines for the one and

half breaker scheme the REF setting will be

revised

42 400 KV GOOTY - TUMKUR - 1 15-07-2017115100 15-07-2017122300Tripped while laying opgw

cablePGCIL (SR-I) PGCIL (SR-II)

PGCIL (SR-I)

stringing

PGCIL(SR-II)

43 220 kV AMBEWADI - PONDA 1 16-07-2017113800 16-07-2017120800 DISTANCE PROTECTION KPTCL GED To-be-discussed

44 220 kV AMBEWADI - PONDA 2 20-07-2017013600 LINE FAULT KPTCL GED To-be-discussed

Annexure-IV

45 400 Kv ALM - SVCTM-I 20-07-2017112700 20-07-2017120200 C-N FAULT TANTRANSCO To-be-discussed

46 400 Kv ALM - SVCTM-II 20-07-2017112700 20-07-2017120300 A-N FAULT TANTRANSCO To-be-discussed

47 400 Kv ALM - SVCTM-II 20-07-2017144300 20-07-2017193200TO ATTEND FAULT

LOCATIONTANTRANSCO To-be-discussed

48 HVDC BHADRAVATHI POLE 1 21-07-2017224800 21-07-2017235300 INTERNAL MINOR ALARM PGCIL (SR-I) PGCIL (WR-I) To-be-discussed

49 400 kV KHAMMAM - KALPAKKA 1 21-07-2017103000 21-07-2017204200AC SUPPLY TO BREAKER

PROBLEMPGCIL (SR-I) APTRANSCO To-be-discussed

50 220 kV CHITTOR - THIRUVALEM 22-07-2017080600 22-07-2017144100RELAY MALOPERATION AT

THIRUVALAMAPTRANSCO TANTRANSCO To-be-discussed

51 400 KV GOOTY - TUMKUR - 1 22-07-2017150700 22-07-2017154500TRIPPED DURING OPGW

WORKSPGCIL (SR-I) PGCIL (SR-II) To-be-discussed

52 400 Kv GAJWEL - BHOOPALAPALLY 2 22-07-2017131300 22-07-2017133600 B PHASE FAULT TSTRANSCO TSGENCO To-be-discussed

53 400 kV GUTTUR - HIRIYUR 2 22-07-2017150300 22-07-2017155300TRIPPED DUE TO RELAY MAL

OPERATIONKPTCL PGCIL (SR-II) To-be-discussed

54 400110 kV ICT 2 AT ALAMATHY 24-07-2017091300 24-07-2017162700TRIPPED ON RESTRICTED

EARTH FAULTTANTRANSCO To-be-discussed

Annexure-IV

220kV LINE-1

ICT 220400 KV

GT1 GT2

400kV LINE-1

400kV LINE-2

600MW 600MW

220kV LINE-2

400kV220kVSummary of Various Special Protection Schemes for 2 x 600 MW UPCL TPP

Adani Power Limited Ahmedabad

Adani Power Ltd Ahmedabad 1

Annexure-V

220 kV LINE-1

ICT 220400 KV

GT-1 GT-2

400kV LINE-1

400kV LINE-2

600 MW 600 MW

220 kV LINE-2

UPCL UDUPI - NETWORK UNDER CONSIDERATION

400 kV220 kV

315 MVAICT-1

315 MVAICT-2

220 kV ndash KEMMAR BUS 400 kV ndash HASSAN BUS

Annexure-V

Existing SPS

Benefits of New Proposals

If both the 400kV Lines out of serviceTripped amp Total Generation is gt 650 MW then Trip Unit-2

Existing SPS logic has been developed in Unit-2 DCS

1 Consideration of all possible contingency cases

2 Unit Backdown (AUTOMATIC) has been proposed in certain contingencies

where Unit tripping is not required After restoration of tripped outlets

Unit may ramp up to full generation

3 Comprehensive logic will be developed in Numerical Relays with adequate

security and reliable detection to avoid mal operation of sps logic

4 Monitoring of SPS logic with necessary alarms and events

Annexure-V

Sr UPCL‐Udupi‐SUMMARY OF SPS TO HANDLE ALL POSSIBLE CONTINGENCIES Sh‐1 of 2

Contingency Cases Action Unit SelectionFor Tripping

1 Power Swing Detected in Impedance reach of Zone‐1 in 400 kV Line

Tripping of One selected unit if both Units ON Each Unit Power gt 400 MW

Unit‐2

2Tripping of one 400 kV Line while another 400 kV Line is already in OFF condition

Tripping of One selected unit if both Units ON Each Unit Power gt 400MW

Unit‐2

3 TrippingOffloading of Both 400 kV Line simultaneously (within 3 sec)

Tripping of One selected Unit if both Unit ON Each Unit Power gt 325 MW Unit‐2

4 TrippingOffloading of all four Transmission Lines Tripping of both Units Both Units

400kVlin

e Overlo

ad Stage PickupSet Point

TimeDelay Action

Stage 1 900 MW 3 Sec Alarm

Stage 2 1100 MW 2 Sec Automatic Backdown upto 450 MW in both Units

Annexure-V

Contingency Cases

Action

Overlo

ading from

400 kV

Line Stage Pickup

Set PointTimeDelay

220 kV

Overlo

Sr Consideration Requirements associated with SPS Implementation

1 400 kV LINE Tripping in Zone‐1 will be blocked under Power Swing DetectionOperation

2 Pole Slip Protection of Generator need to be co‐ordinated with 400 kV Line Power Swing Protection

3 Line Overload Detection will be blocked by Power Swing DetectionOperation

4 Line ZeroUnder Power Detection will be blocked by Power Swing DetectionOperation

Annexure-V

220 kV LINE-1

ICT 220400 KV

GT-1 GT-2

400kV LINE-1

400kV LINE-2

600 MW 600 MW

220 kV LINE-2

400 kV220 kV

315 MVAICT-1

315 MVAICT-2

Annexure-V

Contingency 1 Tripping of one 400kV line

It may lead tohellip1 Overloading of another 400 kV Line

2 Power Swing in another 400 kV Line (specially when 220 kV

Lines are not available)

3 Severe oscillations in running Units

4 Units may loose synchronism and disconnect from network

L1 L2L1L2

Following SPS has suggested to address this contingency

400kV200kV

Contingency Cases

Action

Unit Selection

ForTripping

400kVline Overlo

Stage PickupSet Point

TimeDelay

Stage 1 900 MW 3 Sec Alarm ‐‐‐‐‐‐‐

Stage 2 1100 MW 2 Sec Automatic Backdown upto 450 MW in both Units ‐‐‐‐‐‐‐

Tripping of One selected unit if both Units ON Each Unit Power gt 400 MW Unit‐2

Annexure-V

Contingency 2 Tripping of one 400kV line while other already Tripped

It may lead tohellip

1 Oscillations in running Units

2 Units may loose synchronism and disconnect from

network

3 Overloading of ICTs and subsequent tripping

4 Overloading of 200 kV Lines and subsequent tripping

5 Station blackout

L1 L2L1

400kV200kV

ICT Overlo

kV Side

Stage PickupSetting

TimeDelay

Annexure-V

Contingency 3 Tripping of both 400kV line simultaneously

network

5 Station blackout

L1 L2L1

400kV200kV

ICT Overlo

kV Side

Stage PickupSetting

TimeDelay

Annexure-V

Contingency 4 Overloading of any 220 kV line

This contingency may arise due tohellip1 Tripping of both 400 kV Lines and associated SPS logic fails

to operate (Tripping of any One Unit if both Units running)

2 Overloading of ICTs from 400 kV Side and associated SPS

logic fails to operate

3 Tripping of any one 220 kV lines if both 220 kV lines are in

service and 400 kV outlets are not available

L1 L2L1

400kV200kV

Contingency Cases

Action

Unit Selection

ForTripping

Overlo

ad StagePickupSet Point

TimeDelay

If any SPS does not function Then 200 kV Line will trip by Operation of Line Over Current Function

Annexure-V

Contingency 5 Tripping of all Lines emanating from UPCL (ZERO POWER)

It may lead to1 Over voltage conditions at UPCL Bus

2 Over speed of all the generators because of sudden

load throw

Following SPS has suggested to address these contingencies

1 Zero Power Scheme on 400 kV System and 220 kV System checking the power

flow through 400kV and 200 kV lines and trip all the units in service if there is a

under power condition on all four lines and running units

L1 L2L1

400kV200kV

Sr Contingency Cases Action Unit SelectionFor Tripping

Annexure-V

220kV LINE-1

ICT 220400 KV

GT1 GT2

400kV LINE-1

400kV LINE-2

600MW 600MW

220kV LINE-2

400kV220kV

THANKShellip

Annexure-V

65th Protection Coordination Sub-Committee

29-06-2017

Annexure-VI

Complete outage of 230KV Villianur substation of Pondycherry at 1235 hrs on 19-05-2017

bull Triggering incident Failure of CT in 110kV Villianur-Kurumbapet at Villianur substation

bull 230110kV ICT-1amp2 at Villianur substation tripped on operation of backup Over current protection

bull 230KV Neyveli-Villianur and Pondy-Villianur Line got tripped from NLC amp Pondy ends on operation of DEF and Zone-3 respectively

bull Delayed clearance of fault observed from PMU plot ndash 560ms

bull Load loss 140 MW

ZONE-3

NLC TS-2 BAHUR TrsquoMARTHAN

VILLIANUR

Annexure-VI

Fault cleared in 560ms

Annexure-VI

Complete outage of 400kV Uruvakonda and Jamalamadugu Stations at 1744 hrs on 31-05-2017

bull Triggering incident Tripping of 400kV Kurnool-Narnoor line-1 amp 2 and 400kV Kurnool-Jamalamadugu line-2

bull Loss of supply loss to 400kV Uruvakonda and Jamalamadugu

bull Lines out of service 400kV Gooty-Narnoor 400kV Narnoor-Jamalamadugu-1 400kV Srisailam-Narnoor 400kV Uruvakonda-Mahboobnagar-1amp2

Srisailam Narnoor

Kurnool

Jrsquomadugu UVrsquokonda

Mbrsquongr

Ghanapur

Igt4 Z3

OV DT RCV

Annexure-VI

Kurnool Narnoor

DR trigger ndash 174418501 hrs

Ib=5kA

Zone-3 trip EL Stub optd

Igt4 trip

3 phase Grp AB optd

Kurnool Narnoor

Ib=5kA

Igt4 trip

3 phase Grp AB optd

Kurnool Jamalamadugu

DR trigger ndash 174423979 hrs Vgt1 Trip

DR trigger ndash 174415040 hrs Z3 T1 DT Rcv not observed in DR amp EL

400kV Kurnool-Narnoor line-1

400kV Kurnool-Jamalamadugu line-2

Annexure-VI

bull Points for discussion ndash Location of fault

ndash Zone-3 amp Igt4 trip of 400kV Kurnool-Narnoor line-1amp2

Annexure-VI

Tripping of 220kV Idukki ndashUdumalpet line at 1702 hrs on 05-05-2017

bull B-N and R-N fault in line

bull Delayed clearance observed during 2nd fault

Idukki Udumalpet

DR trigger ndash 170200499 hrs ZONE 1 B-E 366Km

DR trigger ndash 165741849 hrs ZONE 1 B-E amp Zone-2 R-E

Idukki

Udumalpet Lower periyar

New Pallom Kalamassery

Annexure-VI

B-N FAULT

R-N FAULT

ZONE-2

Ar attempt

Udumalpet end DR Annexure-VI

bull Points for discussion ndash Reason for 3 phase trip at idukki end

ndash Relay to give a 3 phase trip in the event of 2nd fault during dead time

Annexure-VI

Tripping of 400kV Kudgi(PG)-Tumkur line-2 and Kudgi(PG)- Kudgi(NTPC) line-1 at 1605 hrs on 06-05-2017

bull 400kV Kudgi(PG)-Kudgi(NTPC) ndash line tripped at Kudgi PG end on R-N zone-1

bull 400kV Kudgi(PG)-Tumkur line tripped from both ends

Kudgi(NTPC)

Tumkur

Kudgi(PG) Narendra

Kohapur

Guttur

Annexure-VI

Kudgi (PG) Kudgi(NTPC)

DR trigger 160547438 hrs Zone-1 optd R-N Ar lockout Ov pick up

FIR DR amp EL not furnished

Kudgi (PG) Tumkur

DR trigger 160546957 hrs NGR buchholz trip Dip in R-phase voltage

DR trigger 160512593 hrs DT Rcv Grp AB optd

400kV Kudgi(PG)-Kudgi(NTPC) line-1

400kV Kudgi(PG)-Tumkur line-2

Annexure-VI

Tripping of 220kV Edamon-Tirunelveli-1amp2 at 1809 hrs on 06-05-2017

bull 220kV Edamon-Tirunelveli-1amp2 tripped from Tirunelveli end only and was in service from Edamon end ZONE-1 R-B-E fault

bull Distance protection at Tirunelveli over-reached and tripped for fault in 220kV Edamom-Pothencode lines

Edamon

Sabarigiri

Tirunelveli Pothencode

Kundara

Edappon

Annexure-VI

Tripping of 400220 kV Ghani ICT-2amp3 at 1405 hrs on 07-05-2017

bull ICTrsquos-2amp3 got tripped on operation of Y-phase over-current protection

bull Delayed clearance observed from PMU data

bull DR amp EL not furnished

Srisailam Narnoor

Kurnool

Mbrsquongr

Ghanapur

Annexure-VI

Tripping of 400kV Ghanapur-Mamidapalli line at 1915 hrs on 08-05-2017

bull Line tripped at Ghanapur end only and was holding from Mamidapalli

Ghanapur Mamidapalli

DR trigger ndash 191329917 hrs Z3 Main-2 opts Event logger Main-2 PSB optd ndash 191541751hrs

DR trigger ndash 191458457hrs R-N Start Breakers did not trip

Malkaram

Ramagundam

Mamidapalli

Nrsquosagar

Gajwel Ghanapur Khammam

Annexure-VI

Tripping of 400220kV ICT-1 at Guttur at 2215 hrs on 09-05-2017

bull ICT-1 tripped on HV side only without any relay indications

bull No fault observed from PMU data

Annexure-VI

Tripping of 400kV Narsapur-Shankarapalli at 0007 hrs on 10-05-2017

bull line tripped at Narsapur end only and holding from Shankarapalli

Narsapur Shankarapalli

DR trigger ndash 000720147hrs Zp T1 Igt3 Start Event logger 75A relay optd ndash 000720098 hrs

CB did not trip

Singareni

Shankarapalli Gajwel

Narsapur

Suryapet

Brsquoply

Rrsquogm

Annexure-VI

Tripping of 400220kV Hyderabad ICT-4 and 220kV lines at Hyderabad substation at 239 hrs on 10-05-2017

bull Triggering incident Bus fault in 220 kV Ghanapur station

bull Observation from PMU data ndash dip observed in Y amp B phase fault cleared in 120ms

bull Elements tripped 220kV lines amp 400220 kV ICT-4

bull FIR not submitted by TSTRANSCO

Annexure-VI

Tripping of 400220kV ICT-1 at BTPS 13-05-2017 at 1941 hrs

bull ICT-1 got tripped on operation of LV side earth fault protection during R-phase to earth fault in 220kV BTPS-Lingapur line

bull Lingapur line DR amp EL were furnished

BTPS Alipura Regulapadu

Lingapur

Annexure-VI

Tripping of 765 kV Kurnool-Thiruvelam line-2 at 2003 hrs on 19-05-2017

bull Triggering incident Failure of R-phase LA at Thiruvelam end

Kurnool Thiruvelam

DR trigger time ndash 200318272 hrs

Main-1 trip Carrier aided trip

3 ph Grp-AB optd DT RCV

Ir ndash 3kA

Dip in Y-phase current observed

Event logger

REF optd - 200318340 hrs

DT send - 200318343 hrs

Zone-1 trip

Initially 1 ph trip and later 3 ph trip due to DT rcv

Event logger

DT rcv - 200318395 hrs

Raichur Kurnool NPS

Tiruvelam

Solapur

Annexure-VI

Tripping of 400220kV ICT-2 at Kalpakka at 1502 hrs on 20-05-2017

bull ICT-2 tripped due to operation of transformer buchholz relay

bull Reason for operation of Buchholz relay may be furnished to PCSC

Annexure-VI

Tripping of 400220kV ICT-2 at KV Kota at 1021 hrs on 23-05-2017

bull ICT-2 got tripped due to mal-operation of transformer oil temperature indicator

bull Remedial actions taken may be furnished to PCSC

Annexure-VI

Tripping of 220kV Kaniambeta-Kadakola line at 1350 hrs on 23-05-2017

bull Line tripped at Kaniambeta end

bull Kaniambeta feeder protection is provided through 220kV bus coupler breaker bay

bull EFR relay operated and B ph pole discrepancy relay operated leading to tripping of Bus coupler CB

bull Loss of infeed to Kaniambeta Ss

Annexure-VI

Tripping of 400220kV ICT-1 at Somanahalli substation at 1724 hrs on 24-05-2017

bull ICT-1 at Somanahalli substation got tripped due to DC Earth fault

bull Findings amp Remedial actions taken may be furnished to PCSC

Annexure-VI

Tripping of HVDC Gazuwaka Pole-1amp2 25-05-2017 at 0945 hrs

bull HVDC pole-1 got tripped due to operation of South filter inter zone protection and

bull HVDC pole-2 got tripped due to operation of differential protection

bull Findings amp remedial actions taken may be furnished to PCSC

Annexure-VI

Tripping of 400kV Kayathar-Karaikudi line 25-05-2017 at 1552 hrs

bull Triggering Incident R-phase to earth fault

Kayathar Karaikudi

Zone-2 3 phase trip

Carrier unhealthy

zone-1 3 phase trip

Kayathar Kamudi Karaikudi

Pugalur

Trichy

Madurai

Annexure-VI

Tripping of 400220kV ICT-1amp3 at Hoody substation of KPTCL at 1230 hrs on 26-06-2017

bull ICT-1 tripped due to arc over of pre-close supervision contact of tip coil -2

bull ICT-3 got tripped on over-loading

Annexure-VI

Tripping of 400kV Simhadiri-Kalpakka line-2 at 503 hrs on 28-05-2017

bull Line tripped on mal-operation Teed Differential Protection at Simhadiri end and direct trip was received at Kalpakka

bull Y-Phase to earth fault had occurred in 400 kV Vijayawada-Vemagiri line-3

Annexure-VI

Tripping of 400kV Ramagundam-Gajwel at 0007 hrs on 29-05-2017

bull Over voltage stage-1 had operated at Gajwel end

bull Ramagundam end did not trip as direct trip was received from Gajwel

bull DR amp EL of Gajwel end not furnished

Annexure-VI

Tripping of 400kV Gajwel-Ghanapur line at 0007 hrs on 29-05-2017

bull Line tripped on operation of over voltage protection at Gajwel and direct trip was received at Ghanapur

bull DR and EL of Gajwel end were not furnished

Annexure-VI

Minutes-65 (CoverPage)

PCSC-65_201707261231_0001


PCSC-65_201707261212

PCSC Address List _1807

Minutes-65 (Body)

Annexure-I (Attendance-65)

Annexure-II (GOA-65)

Annexure-III (P-REC)

Annexure-IV (PRM)

Annexure-V (UPCL SPS)

Annexure-VI (SRLDC-65)