2-QLY-Apr'18-Jun'18.Pdf

Distribution list:

1. Chief Engineer, Trans (O&M) , Bihar State Power Holding Co. Ltd, Vidyut Bhawan, Bailey Road, Patna-800021

2. Chief Engineer (Commercial & Revenue), Jharkhand Urja Vikas Nigam Limited , Engineering Building , HEC Complex , Dhurwa, Ranchi – 834 004.

3. Sr. General Manager (PS) /(O&M) OPTCL, P.O. Mancheswar Rly. Colony Bhubaneswar 7510 16

4. Chief Engineer (CLD) , WBSETCL, P.O. Danesh Sheikh Lane, Andul Road, Howrah-7111 09

5. Vice President (Sys Operation), CESC, Chowringhee Square, Kolkata-700001 .

6. Chief Engineer (CLD), Damodar Valley Corporation P.O. Maithon Dam, Dist. Dhanbad, Jharkhand-828207

7. Chief Engineer (Trans.) Power Deptt., Govt. of Sikkim, Gangtok-731010

8. General Manager, FSTPS, NTPC Ltd., P.O. Nabarun, Dist. Murshidabad, West Bengal-742236

9. General Manager, KhSTPS, NTPC Ltd., P.O. Deepti Nagar, Dist. Bhagalpur, Bihar-813203

10. General Manager, TSTPS, NTPC Ltd. P.O.Deepsikha, Dist. Angul, Orissa-759147

11. Executive Director, ERTS-I, Powergrid, RHQ-5th & 6th Floors, Alankar Place, Boring road, Patna-800001 (Bihar)

12. Executive Director, ERTS-II, Powergrid, RHQ-J-1-15, Sector- V, Saltlake, Kolkata-700091.

13. Executive Director, Odisha projects, Bhubaneswar Office, Plot no. 27, Sahid Nagar, Bhubaneswar-751007

14. Chief Engineer, Rangit HEP, NHPC, P.O. Rangit Nagar, South Sikkim-737111

15. General Manager, Teesta-V HEP, NHPC, Singtam, E. Sikkim – 737134

16. General Manager (Electrical), Adhunik Power & Natural Resources Ltd. Lansdowne Towers, Kolkata-700020

17. Station Head & General Manager (O&M), Maithon Power Ltd., MA-S, Gogna Colony, P.O. Maithon Dam, Dist.- Dhanbad, Jharkhand-828207

18. Chief Electrical Service Engineer, Eastern Railway, Fairlie Place, 17, Netaji Subhas Road, Kolkata - 700 001

19. Chief Electrical Engineer, South Eastern Railway, 11, Garden Reach Road, Kolkata – 700 043.

20. Associate Vice President, GMR KEL, 29, Satyanagar, Bhubaneswar-751007.

21. General Manager (I/C) NTPC Barh Thermal Power Station, Patna, Bihar-803213

22. AGM (O&M) Gati Infrastructure Pvt. Ltd. Chuzachen Hydroelectric Power Project Lower Bering Karabari,Pakyong East Sikkim – 737106

23. Director, Jindal India Thermal Power Ltd. Plot No. 12, Local Shopping Complex Sector B1, Vasant Kunj, N. Delhi - 110070

24. Sr. Vice President (Power), Sesa Sterlite Ltd., Bhurkahamunda, P.O.-Sripura, Jharsiuguda, Odisha-768202

Copy to:

1. Member Secretary, ERPC

2. ED, NLDC (POSOCO) B-9, Qutab Institutional Area, Katwaria Sarai, New Delhi-110016 POWER SYSTEM OPERATION CORPORATION LIMITED EASTERN REGIONAL LOAD DESPATCH CENTRE QUARTERLY REPORT (AS PER IEGC CLAUSE 6.5.2 a)

Document Management Information:

Document Name Quarterly Report –APR’18 – JUN’18

Document ID ERLDC/ Quarterly Report /2018-19/ APR’18 –JUN’18/V00

Version No. 00 Date 19/07/18

Classification Public

Document Modification History Date Version Name Comment

INDEX

SL PAGE NOS NO.

1 Power Supply Position 1-2 1(a) Peak Demand Met and Unrestricted Demand 1 1(b) Energy Met and Requirement 2 2 (a) Schedule vs Actual Drawal by States 3 2 (b) System constraints in regional grid 3 3 Quality of service 4-5 3(a) Frequency Profile 4 3(b) Voltage Profile 5 4 Inter-regional exchanges 5 5 Outage of important Transmission Elements 6 6 Important events 6 Generation of Central sector Thermal power stations and their 7 7 Declared Capacity 8 Event-Reporting 7-12 8.1 Grid Incidences in ER system 7-12 Annexures Annexure- I (System Constraints) 13-24 Transmission Constraints) 13-15 Inter-connecting Transformer Constraints 16-18 Low Voltage 18-19 High Voltage 19 Annexure- II Figs. 19-24 Annexure- III 25 Annexure- IV 25 Annexure- V 26

POWER SYSTEM OPERATION CORPORATION LIMITED EASTERN REGIONAL LOAD DESPATCH CENTRE QUARTERLY REPORT (AS PER IEGC CLAUSE 6.5.2 a)

Quarter No.1 Period from: APR-18 to JUN-18

Brief report on Regional Power System / Performance of the grid is given below:

1. POWER SUPPLY POSITION a) Peak Demand Met and Unrestricted Demand (MW) MONTH STATE PK REQ PK DMD MET SHORTGE % BSPHCL 5053 4620 9.4 JUVNL 1299 1240 4.8 DVC 2950 2950 0.0 APR-18 OPTCL 4472 4472 0.0 WBSETCL 8538 8538 0.0 SIKKIM 99 99 0.0 REGION 21361 21361 0.0 BSPHCL 5008 4824 3.8 JUVNL 1319 1319 0.0 DVC 2916 2916 0.0 MAY-18 OPTCL 4703 4703 0.0 WBSETCL 8731 8731 0.0 SIKKIM 104 104 0.0 REGION 21994 21994 0.0 BSPHCL 5000 4911 1.8 JUVNL 1301 1216 7.0 DVC 2922 2922 0.0 JUN-18 OPTCL 4741 4741 0.0 WBSETCL 8896 8896 0.0 SIKKIM 88 88 0.0 REGION 22677 22677 0.0

b) Energy Met and Requirement (MU) MONTH STATE ENERGY ENERGY AVAILABILITY ENERGY ENERGY REQ OWN SCHD DEV. MET SHORTAGE SOURCE DRWL % BSPHCL 2425 98 2337 -17 2418 0.3 JUVNL 722 222 451 21 695 3.8 DVC 2071 3674 -1621 17 2071 0.0 APR-18 OPTCL 2366 1519 793 55 2366 0.0 WBSETCL 4695 3601 1041 19 4661 0.7 SIKKIM 41 44 -3 41 0.0 REGION 12321 9114 3045 92 12251 0.6 BSPHCL 2706 77 2582 -24 2634 2.7 JUVNL 753 161 561 21 743 1.3 DVC 2146 3554 -1452 44 2146 0.0 MAY-18 OPTCL 2848 1656 1121 72 2848 0.0 WBSETCL 5016 3584 1352 60 4996 0.4 SIKKIM 39 43 -4 39 0.0 REGION 13509 9032 4207 168 13406 0.8 BSPHCL 2694 70 2636 -25 2680 0.5 JUVNL 713 161 529 19 709 0.6 DVC 2088 3147 -1079 20 2088 0.0 JUN-18 OPTCL 2833 1416 1304 112 2833 0.0 WBSETCL 5157 3558 1505 76 5138 0.4 SIKKIM 37 40 -3 37 0.0 REGION 13521 8351 4934 199 13485 0.3

2. SCHEDULE vs ACUAL DRAWAL BY STATES

Month STATE / UT Schedule (MU) Drawal (MU) Dev (MU) APR-18 BSPHCL 2337 2320 -17.2 JUVNL 451 472 21.2 DVC -1621 -1604 17.2 OPTCL 793 848 55.0 WBSETCL 1041 1060 18.8 SIKKIM 44 41 -2.9

MAY-18 BSPHCL 2582 2557 -24.5 JUVNL 561 582 21.0 DVC -1452 -1408 43.7 OPTCL 1121 1192 71.6 WBSETCL 1352 1412 59.8 SIKKIM 43 39 -3.8

JUN-18 BSPHCL 2636 2610 -25.4 JUVNL 529 548 18.6 DVC -1079 -1059 20.3 OPTCL 1304 1416 112.3 WBSETCL 1505 1581 75.9 SIKKIM 40 37 -2.5

2. SYSTEM CONSTRAINT IN REGIONAL GRID

The details of the system constraint in Eastern Region are given in Annexure-I & II

3. QUALITY OF SERVICE a) Frequency Profile (% time)

% of time of the month frequency remained Month <49.9 Hz 49.9-50.05 Hz > 50.05 Hz FDI (% of time) APR-18 12.77 79.60 7.63 20.40 MAY-18 21.27 71.16 7.56 28.84 JUN-18 11.81 77.08 11.11 22.92

Following curves are enclosed:

Annexure III - Frequency duration curve for APR-18 Annexure IV - Frequency duration curve for MAY-18 Annexure V - Frequency duration curve for JUN-18

b) Voltage Profile

765 KV 400 KV 400 KV 400 KV 400 KV 400 KV BIHARSHARIFF NEW RANCHI MUZAFFARPUR BINAGURI JEERAT MAITHON

MONTH Max Min VDI Max Min VDI Max Min VDI Max Min VDI Max Min VDI Max Min VDI (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%)

APR-18 797.3 762.5 0.0 421.5 385.7 0.1 428.0 397.4 13.5 427.9 383.4 8.6 425.3 404.9 4.9 425.3 397.6 1.5 MAY-18 804.6 756.3 0.8 422.4 386.6 0.4 425.0 394.2 2.5 427.2 378.7 6.6 425.7 405.1 6.7 426.9 397.8 1.6 JUN-18 799.0 751.7 0.0 416.3 383.6 0.0 420.8 392.8 0.0 423.0 376.4 1.6 425.0 406.3 8.6 421.5 394.8 0.5

400 KV 400 KV 400 KV 400 KV 400 KV 400 KV SUBHASHGRAM JAMSHEDPUR ROURKELA JEYPORE MERAMUNDALI SASARAM MONTH Max Min VDI Max Min VDI Max Min VDI Max Min VDI Max Min VDI Max Min VDI (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%) (KV) (KV) (%)

APR-18 425.9 405.8 22.7 410.9 401.8 0.0 429.9 372.0 1.4 417.0 396.0 0.0 420.3 389.0 0.1 428.0 383.0 9.3 MAY-18 425.9 407.5 10.7 412.8 402.3 0.0 426.9 395.7 0.6 415.0 398.0 0.0 416.0 384.0 0.0 428.0 376.0 6.8 JUN-18 424.5 402.3 5.9 413.3 400.6 0.0 425.7 384.9 3.9 411.5 397.0 0.0 411.7 378.1 0.1 425.5 369.4 3.1

4. Inter-regional exchanges during the quarter APR-18 to JUN-18 All figures are in Million Units. 220 KV 132 KV 132 KV 400 KV400 KV 400 KV Birpara-Salakati D/C Salakati-Geleyphu Rangia-Matunga Binaguri-B'gaon D/C Alipurduar-B'gaon D/C Jeypore-Gazuwaka MONTH Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Apr-18 53.6 -0.1 0.2 -6.7 10.7 -0.3 116.6 -9.2 100.1 -24.1 437.3 0.0 May-18 40.4 -1.0 4.6 -1.4 22.6 0.0 90.7 -40.1 42.0 -79.9 354.5 0.0 Jun-18 45.7 -0.5 13.0 0.0 30.1 0.0 166.3 -10.0 63.6 -37.4 376.9 0.0

400 KV765 KV 220 KV 220 KV 400 KV 400 KV Talcher I/C Angul-Srikakulam D/C Budhipadar-Raigarh B'padar-Korba D/C Jharsuguda-Raigarh Q/C Ranchi-Sipat D/C MONTH Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Apr-18 163.9 -39.6 792.9 0.0 45.6 -0.2 0.0 -125.2 10.2 -134.2 1.2 -100.5 May-18 33.2 -289.7 739.1 0.0 8.9 -17.8 0.0 -84.0 0.0 -411.8 0.1 -171.6 Jun-18 50.6 -299.3 534.2 -0.8 1.5 -25.1 0.0 -71.3 0.0 -498.4 0.0 -170.0

765 KV 765 KV 500 KV HVDC 220 KV 132 KV 132 KV Ranchi-D'Jaygarh D/C J'sguda-D'Jaygarh D/C Pusauli HVDC/ AC Pusauli-Sahupuri Karamnasa-Sh'puri K'nasa-Chandauli MONTH Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Apr-18 56.6 -85.9 16.6 -227.0 12.7 -26.9 103.8 0.0 0.0 0.0 0.0 0.0 May-18 27.9 -168.0 26.7 -213.4 67.6 -30.0 118.6 0.0 0.0 0.0 0.0 0.0 Jun-18 1.9 -303.3 3.6 -378.1 98.7 -0.2 123.4 0.0 0.0 -13.7 0.0 0.0

132 KV132 KV 400 KV 400 KV 400 KV 765 KV Rihand-Sonenagar Rihand-Garwah Mzf'pur-Grk'pur D/C Patna-Balia Q/C B'Sharif-Balia D/C Gaya-V'nasi D/C MONTH Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Exp Imp Apr-18 0.00 0.00 0.01 -14.21 160.68 -2.10 409.59 -0.02 145.84 0.00 168.40 -0.22 May-18 0.00 0.00 0.00 -18.59 261.14 -0.66 557.22 -0.01 258.65 0.00 175.63 -0.77 Jun-18 0.00 0.00 0.02 -9.84 293.92 -0.20 442.70 -0.15 221.96 -0.01 179.72 -0.28

765 KV400 KV 400 KV HVDC Gaya-Balia Barh/ Motipur-Grk'pur D/C B'shariff-V'nasi D/C ALPD-AGRA-(3&4 MB, TB) MONTH Exp Imp Exp Imp Exp Imp Exp Imp Apr-18 239.71 0.00 122.58 0.00 58.78 -4.46 0.04 -0.03 May-18 317.36 0.00 126.18 -0.24 52.13 -14.25 144.23 -0.04 Jun-18 283.99 0.00 68.22 -35.09 52.26 -17.32 269.67 0.00

5. Outage of important Transmission Elements

During APR-18 to JUN-18 the following lines/elements in ER system were under outage:

Sl. Name Date of Reason Remarks No. Outage 1 220 KV SATGACHIA-JEERAT D/C 27/12/14 TOWER COLLAPSE 2 400 KV MOTIHARI- GORAKHPUR -II 07/04/18 SF6 GAS DUCT LEAKAGE IN MAIN AND TIE BAY ; 3 400 KV IBEUL JHARSAGUDAD/C 29/04/18 TOWER COLLAPSE AT LOC 44,45 4 TO CONTROL CRITICAL LOADING ON 220 KV BUDHIPADAR - KORBA II 07/05/18 220KV KORBA EAST & DSPM NETWORK IN CHHATTISGARH(kept open from Korba end) 5 400 KV MPL-MAITHON D/C 10/05/18 TOWER COLLAPSED AT LOC NO -63/64/65

6. Important events APR-18: Charging Charging SL NO Element Name Owner Remarks Date Time 240 MVAr Line reactor of 765 KV 1 PGCIL 12/04/18 22:00 Only Line Reactor charged Angul-Jharsuguda IV at Angul 400 KV New-Duburi-TSL 2 OPTCL 17/04/18 15:49 (Kalinganagar) I

MAY-18: SL NO Element Name Owner Charging Charging Remarks Date Time 1 400/132 kV, 200 MVA ICT-I at NPGC 04/05/18 13:54 NPGC SS 2 220kV Alipurduar(PG)- WBSETCL 22/05/18 17:53 Loaded on 06/06/18 at 16:04hrs. Alipuduar(WB)-II 3 315MVA, 400/220/33KV ICT#2 at DVC 23/05/18 13:37 Idle charged from 400kv Side & DSTPS 220kV side not constructed yet 4 220kV Darbhanga(DMTCL)-laukhai BSPTCL 23/05/18 18:42 I 5 220kV Darbhanga(DMTCL)-Laukahi BSPTCL 23/05/18 18:48 II 6 220kV Alipurduar(PG)- WBSETCL 31/05/18 15:41 Loaded on 06/06/18 at 16:04hrs. Alipuduar(WB)-I

JUN-18: SL Element Name Owner Charging Charging Remarks NO Date Time 1 220kV Darbhanga(DMTCL)- BSPTCL 12/06/18 16:06 Darbhanga(BSPTCL)-I 2 125MVAR Bus Reactor II at Baripada PGCIL 28/06/18 18:45 404/398 kV 6

3 400kV Dikchu-Rangpo PGCIL 30/06/18 14:45 4 (+/-) 550MVA Jeypore STATCOM PGCIL 30/06/18 21:58 Started on 27/06/18

7. Generation of Central sector Thermal power stations and their Declared Capacity

Gen. Station APR-18 MAY-18 JUN-18 GEN (MU) AVG DC GEN AVG DC GEN AVG DC (%) (MU) (%) (MU) (%) FSTPP I & II 521.0 51.025 785.2 74.791 925.0 93.895 FSTPP III 286.9 93.921 306.3 95.362 233.1 77.792 KhSTPP-I 453.9 94.144 493.1 95.866 449.2 92.067 KhSTPP-II 888.2 96.906 733.4 74.606 675.4 75.298 TSTPP Stg I 614.1 91.420 658.7 94.426 590.1 87.479 BARH Stg II 785.3 92.786 742.4 83.654 792.9 95.157 BRBCL 115.4 53.595 151.3 45.370 147.8 46.412 MTPS II 175.0 81.648 146.2 66.160 84.6 36.791

8. Event-Reporting (Clause 6.9.6):

8.1 Grid Incidents in ER system The section may detail near miss situations incidents of multiple elements outage natural calamities impacting the power system oscillations observed in the system etc.

Sl. Region Outage Event Generation Load Category No. Date Time Loss (MW) Loss as per CEA (MW) Grid Standards 1

At 09:48 hrs 400 KV Motihari – Gorakhpur I and II tripped on Y-N and B-N fault respectively. Thereafter tripping of 400 kV Motihari – 7-Apr- Gorakhpur D/C at 09:56 hrs in R-Y-B fault resulted ERLDC 09:56 0 160 GD-I 18 total power failure at 400/132 kV Motihari S/S and other radially connected areas (Birganj, Surajpura, Parwanipur in Nepal; Ramnagar, Betiah, Raxaul, Motihari, Dhaka in Bihar).

Sl. Region Outage Event Generation Load Category No. Date Time Loss (MW) Loss as per CEA (MW) Grid Standards 2 220 kV Maithon - Dhanbad D/C, 220 kV Maithon - Kalyaneswari D/C and 220 kV Maithon - Dumka - II 7-Apr- ERLDC 17:20 tripped along with 220 kV B/C bay at Maithon 0 0 GI-I 18 tripped due to B/B protection operated at Maithon.

3 Unit 7 & 8 at CTPS – B, 220 kV Bokaro B – CTPS B D/C, 220kV Dhanbad – Giridih D/C and 132kV CTPS A – Putki – Patherdhi link were open prior to the disturbance. At 19:40 hrs 220 kV Maithon – Dhanbad - I tripped on B-N fault. While restoration of this circuit, 220 kV Maithon – Dhanbad – II also tripped at 20:10 hrs resulting Dhanbad radial with Kalyaneswari 11- through 220 kV Kalyaneswari – CTPS A – CTPS B – ERLDC 20:10 0 700 GD-I Apr-18 Dhanbad section (220 kV Bokaro B – CTPS B D/C was kept open). At 20:15 hrs 220 kV Kalyaneswari – CTPS – I tripped due to jumper snapping (suspected) and at 20:18 hrs 220 kV Kalyaneswari – CTPS – II tripped on overload. At the same time 220 kV Joda – Jindal S/C tripped from Joda end resulting load loss at radially fed area i.e. Jamshedpur (DVC) through 220 kV Joda – Jindal – Jamshedpur section.

4 At 06:43 hrs, 220 kV Tashiding Rangpo S/C and 220 kV Tashiding New Melli S/C tripped in Y-N fault resulting tripping of running unit due to loss 15- ERLDC 06:43 of evacuation path. At the same time 220 kV 50 0 GD-I Apr-18 Jorethang New Melli - I tripped from Jorethang end (successful A/R operation at New Melli end) in earth fault protection.

Sl. Region Outage Event Generation Load Category No. Date Time Loss (MW) Loss as per CEA (MW) Grid Standards 5 At 10:37 hrs, 220 kV Subhasgram - EMSS D/C tripped due to operation of line differential relay 17- at EMSS end (R phase for Circuit II and B phase for ERLDC 10:37 0 500 GD-I Apr-18 Circuit I) resulting load loss at radially connected area i.e. New Cossipore, Kasba, Dum Dum and B/T road.

6 220 kV Purnea - Madhepura II was in opened 30- condition due to O/V. At 05:48 hrs 220 kV Purnea - ERLDC 05:48 0 60 GD-I Apr-18 Madhepura I tripped on B-N fault causing load loss at Madhepura, Supaul and Lahan (Nepal).

7 At 20:38 hrs, HV side CT in B phase connected to 8- 150 MVA ICT-II blasted, leading to a suspected ERLDC May- 20:38 0 310 GD-I bus bar protection operation at 220 KV Main bus 18 and subsequent voltage loss at Bodhgaya.

8 10- At 06:11 hrs, 400 kV Andal - RTPS D/C and 400 kV ERLDC May- 06:11 Andal Jamshedpur D/C tripped resulting total 900 0 GD-I 18 power failure at Andal S/S

9 220 kV Muzaffarpur - Hazipur - II was under shutdown. At 18:38 hrs 220 kV bus I at Muzaffarpur tripped resulting outage of 220 kV Muzaffarpur - Hazipur - I, 400/220 kV ICT - I & II at Muzaffarpur, 220/132 kV ICT at Muzaffarpur and 11- 220 kV Muzaffarpur - MTPS - I. Though other ERLDC May- 18:38 0 240 GD-I elements are in service at 220 kV level of 18 Muzaffarpur, both the incoming feeders of Hazipur S/S tripped resulting total power failure at Hazipur, Chapra, Jandaha. Interruption of supply of power occurred at Dhalkebar due to tripping of 220/132 kV ICT at Muzaffarpur.

10 220 kv Farakka - Lalmatia T/L tripped at 03:25 hrs 14- from Farakka end on overcurrent relay operation. ERLDC May- 03:25 . At the same time 132 KV Kahalgaon (NTPC) - 0 83 0 18 Lalmatia T/L tripped and following relay appeared :- E/F zone 1 fault location 28.35 mt. ,IA=2.844 9

Sl. Region Outage Event Generation Load Category No. Date Time Loss (MW) Loss as per CEA (MW) Grid Standards Kamp , Ib= 699.5 A , Ic= 927.8 A, 132 Kv Kahalgaon (BSPTCL)- Lalmatia (Sahebgunj) T/L also tripped at 03:17 hrs. Bursting of R-Phase bushing of 20 MVA Transformer H.V side. occurred during the on-going adverse weather at Lalmatia complex

11 At 16:30 Hrs R ph LA blasted in 220 KV Jaynagar- Laxmipur ckt I at Jaynagar yard, which led to remote end tripping of some 220 KV ckts and 25- backup overcurrent/reverse zone clearing of some ERLDC May- 16:30 ckts from Jaynagar end. 428 98 GD-I 18 As a result, 220 KV Jaynagar substation became dead and due to loss in evacuation paths,160 MW in Upper Kolab(unit 1 and 3) and 268 MW in Balimela(Unit 3,4,5,6,7,8) tripped.

12 At BODHGAYA GSS, Total power failed after 26- tripping of both 220 KV Gaya(PG)-Bodhgaya ckt-1 ERLDC May- 12:06 0 248 GD-I and 2 at 12:06 Hrs from Gaya (PG) end. There was 18 no any tripping at GSS Bodhgaya end.

13 220 KV Gaya Bodhgaya d/c tripped from Gaya(PG) end only on 3-Ph Fault, zone III . Actually 28- fault was in 220 KV Bodhgaya-Khizersarai-I line. ERLDC May- 21:41 0 205 GD-I During anti-theft charging of the said line 220 KV 18 Gaya Bodhgaya d/c tripped from Gaya(PG) end. Fault was not cleared by Boghgaya.

At 19:04 hrs R-N fault took place in 400 KV Malda- 14 Purnea-2 line and during A/R attempt Bus bar protection operated at Malda 400 KV and all the 28- element tripped. Then Dalkhola B/C tripped in O/C ERLDC May- 19:04 0 410 GD-I and 220 kV Purnea-Purnea D/C and 220 kV 18 Kishangunj-Dalkhola D/C tripped in DEF leading to wide spread blackout at Malda,Dalkhola and Purnea

Sl. Region Outage Event Generation Load Category No. Date Time Loss (MW) Loss as per CEA (MW) Grid Standards 15 220 kV Ranchi - Hatia D/C tripped in R-B fault at 30- 18:22 hrs. At same time 220 kV Hatia - Patratu D/C ERLDC May- 18:22 tripped on overreaching the fault resulting 0 60 GD-I 18 interruption of power at 220/132 kV Hatia S/S and its surrounding areas

31- Total power failure occurred at Daltongunj after ERLDC May- 18:43 tripping of 400 kV Sasaram - Daltongunj D/C at 0 30 GD-I 18 18:43 hrs on R-N and B-N fault respectively.

Tripping of 220 kV New Purnea - Madhepura D/C 5-Jun- ERLDC 10:20 on R-N fault resulted total power failure at 0 133 GD-I 18 Madhepura, Supaul and Lahan (Nepal)

220 kV New Purnea - Madhepura I was out of service since GD at Madhepura at 10:20 hrs on 5-Jun- same day. At 16:32 hrs 220 kV New Purnea ERLDC 16:32 0 160 GD-I 18 Madhepura II tripped on Over current resulting total power failure at Madhepura Supaul and Lahan (Nepal)

19 400 kV HEL - Subhasgram D/C tripped on B-N fault 10- ERLDC 21:52 resulting station black out at Haldia due to loss of 550 0 GD-I Jun-18 evacuation path

Sl. Region Outage Event Generation Load Category No. Date Time Loss (MW) Loss as per CEA (MW) Grid Standards 20

At 10:58 hrs, 220 kV Patna - Sipara T/C, 220 kV Sipara Khagul S/C, 220 kV Sipara Fatuah S/C, 15- ERLDC 10:58 220/132 kV ICT - I, II & III at Sipara tripped on bus 0 328 GD-I Jun-18 bar relay operation at Sipara resulting load loss at Sipara and its surrounding area.

21 At the time of taking shutdown of main CB connected to GT of Bakreswar unit II and connecting the unit to transfer bus via bus coupler CB, all elements connected to bus I tripped on LBB 19- ERLDC 10:10 operation. It is suspected that NIT (Normal 210 0 GI-II Jun-18 Intermediate Switch) remained in the intermediate position in the case of bus coupler CB between 400 kV main and transfer bus, which led to LBB initiation.

22 At 04:39 Hrs 220 kV Purnea - New Madhepura D/C 26- ERLDC 04:39 tripped on R-N fault resulting load loss at 0 150 GD-I Jun-18 surrounding area

ANNEXURE- I System Constraints

1.1. Transmission Constraints Has the constraint Season/ Figure/ occurred in Sl. No Corridor Antecedent Description of the constraints table no. earlier Conditions quarter? Details thereof

Constraints:

At present power generated at Teesta-III, Dikchu, Chujachen, Jorthang, Tasheding along with Teesta-V is pooled at Rangpo and evacuated through 400 kV Rangpo-Binaguri D/C. Apart from high & moderate hydro season, when almost all these plants operate at 110% of their MCR, these plants are always scheduled upto their respective maximum allowable limit during peak hours. Unrestricted High and scheduling of the hydro IPPs leads to violation moderate of (n-1) security limit of 400 kV Rangpo- 400kV Rangpo- Hydro 1 Binaguri D/C which is strung with Tw. Moose Fig A1 Yes Binaguri D/C Season & conductor. also during evening peak Remedial Actions:

Till commissoing of 400kV Teesta III-Rangpo- Kishanganj D/C, which is part of the final transmission system of Sikkim HEPs, maximum generation of Teesta-III has been restricted to 782MW so that power flow through Rangpo-Binaguri 400kV D/C remains limited to 1700MW and SPS at Rangpo has been installed for tripping units at all plants except Teesta-V, in the event of (n-1) contingency of Rangpo-Binaguri D/C line

Constraints:

220 kV Major part of Jharkhand’s capital city Ranchi’s Yes (All season 2 Ranchi(PG)- All season load and nearby area is supplied from, 220 kV Fig A2 last year) Hatia D/C Hatia substation. Further, Bihar imports significant power through 220kV Hatia-PTPS- Tenughat-Biharshariff route. PTPS power station has been decommissioned and in the

Has the constraint Season/ Figure/ occurred in Sl. No Corridor Antecedent Description of the constraints table no. earlier Conditions quarter? Details thereof

event of less generation or outage of unit at Tenughat, 220 KV Ranchi(PG)-Hatia D/C gets overloaded and N-1 security criteria is not satisfied during that period.

Remedial Actions:

Maintaing good generation at Tenughat and expediting commissioning of 3X800MW thermal power plant at Patratu by PUVNL and reducing drawl by Bihar through 220 kV Tenughat Biharsariff.

400/220/132kV Daltonganj S/Stn of POWERGRID together with 400kV Sasaram- Daltonganj D/C line has recently been commissioned and Latehar-Daltonganj D/C line of JUSNL has been LILOed at 132kV Daltonganj(PG). As the LILO has been constructed using Panther conductor, only Daltonganj load is supplied radially from PG S/Stn. However 400 kV Sasaram-Daltengonj D/C line tower collapsed on 31st May 2018 and only restored on 5th July 2018, Thus during that period the earlier configuration of feeding Datengonj load from Hatia resulted in higher loading of 220kV Ranchi-Hatia D/C. If the existing Hatia-Lohardaga-Latehar-Daltonganj D/C line of JUSNL is made ready to operate at its rated voltage of 220kV, a large part of the load around Hatia can be met from Daltonganj(PG), thereby off-loading Ranchi(PG) source. In the long run, operation of 220kV Patratu-Tenughat-Biharshariff line at its rated voltage of 400kV together with Patratu-N.Ranchi 400kV D/C line is necessary to overcome the constraint as well as enhance the reliability of power evacuation from these two stations.

Has the constraint Season/ Figure/ occurred in Sl. No Corridor Antecedent Description of the constraints table no. earlier Conditions quarter? Details thereof

Constraints:

Major load of Bihar’s Capital city Patna is fed from 220 kV Sipara Substation. Further, Sipara is conneted with Khagaul as well as well as Fatuah at 220 kV level. These are also major load centers normally fed in radial mode from Patna (except Fatuah, which is usually supplied radially from Biharshariff). Whenever 220kV Sipara-Khagaul is kept in service, it leads to very high loading of 220 kV Patna-Sipara D/C and it did not satisfy N-1 security criteria for most of the time in last quarter.

220 kV Patna- Remedial Actions: Fig A3(i) Yes (All season 3 All season Sipara D/C and (ii) last year) The third circuit of 220kV Patna-Sipara line is already commissioned however at present this line cannot be operated in parallel with the other two circuits as impedance of the third circuit is 50% of that of other two circuits. So, it is being operated as Patna-Sipara-Khagaul line with no off-take at Sipara (implemented by split-bus operation at Sipara) Hence, the reduction in loading of other two circuits of Patna-Sipara line was not adequate. Further as these ckts are of very short length (only 400 meters (ckt 1&2) & 200 m(ckt-3)) they are recommended for uprating by reconductoring with HTLS conductor

1.2 ICT Constraints Has the constraint Season/ Figure/ occurred in S. No ICT Antecedent Description of the constraints table no. earlier Conditions quarter? Details.

Constraints:

220 KV side of Patna is connected to Sipara, Fatuah & Khagaul. Sipara load is supplied from Patna. Generally Khagaul load is supplied from Sasaram but in case of loading constraint in Sasaram ICT it is supplied from Patna. Fatuha is generally supplied from Biharshariff. But sometimes it was also supplied from Patna. So due to this most of the time total loading though both the ICTs were more than 700 Yes (All Fig No.B- All time MW. Although at present the (n-1) security season last 400/220 kV 1 1 criteria is not violated. However with such high year) ICTs at flow allowing shutdown of any 500 MVA Patna transformer will be difficult. .

Remedial Actions:

Replacement of 3rd 315 MVA ICT with 500 MVA ICT

Constraints:

Though Gaya is having,1x 500 + 1x 315 MVA 400/220kV ICT at their S/s but due to high drawal of power by Bihar, tripping of this 500 MVA ICT may cause cascade tripping of other 400/220 kV Yes (All 315 MVA ICT on overload, thereby causing Fig No.B- 2 ICTs at All time season last complete loss of supply around Gaya area. 2 Gaya year) However, in this quarter no such incident was reported.

This Cascaded tripping of ICT & loss of load in Bihar Pocket may be prevented by replacing the 315 MVA ICT with 500 MVA capacity

Has the constraint Season/ Figure/ occurred in S. No ICT Antecedent Description of the constraints table no. earlier Conditions quarter? Details.

Remedial Actions:

Replacement of other 315 MVA with 500 MVA one will help in meeting the N-1 contingency criteria for more number of hours during the day. However even after this augmentation system may not remain N-1 compliant during some part of the day and thus to make it fully N-1 secured, another 315/500 MVA ICT may be planned at Gaya. Till 3rd ICT is installed, it is recommended that an SPS/load rejection scheme may be installed at Gaya to take care of ICT contingencies.

Constraints:

220 kV side of 400 /220kV substation at Maithon is connected with Dhanbad and Kalyaneswari. Further from Dhanbad connectivity is there to Giridih, Nimiaghat, Putki etc. besides Chandrapura TPS. From Kalyaneswari loads of Kalipahari, Burnpur, Kumardubi etc. are supplied. In addition, JUSNL also draws around 100-110 MW at its Dumka S/Stn through 220kV Maithon(PG)- 400/220 kV Dumka D/C tie line. Yes (All Fig No.B- 3 ICTs at All time These S/Stns are situated in coal belt having season last 3 Maithon major industrial and mining load. As the year) generation of DVC thermal power plants connected at 220 kV level was low, DVC had to draw heavy power through Maithon ICT to meet these loads. Thus (n-1) security got violated. The present capacity of 400/220kV ICTs at Maithon being 2X500MVA, tripping of any 500 MVA ICT could have led to loss of the other 500 MVA ICT on overload during peak hrs particularly with low generation at Mejia and CTPS.

Has the constraint Season/ Figure/ occurred in S. No ICT Antecedent Description of the constraints table no. earlier Conditions quarter? Details.

Remedial Actions:

After implementation of 400kV bus-splitting arrangement at Maithon loading of ICTs has somewhat reduced However, a 3rd 315 MVA, 400/220kV ICT is already planned for installation at Maithn, under ERSS-XX scheme.

1.3 Nodes Experiencing Low Voltage S. No Nodes Season/ Description of the constraints Figure/ Has the constraint Antecedent table no. occurred in earlier Conditions quarter? Details. Constraints: Jeerat and Subhasgram are major load centers of West Bengal having 4 X 315 MVA 400/220 kV ICTs at Jeerat and 4 X 315 MVA + 1X 500 MVA 400/220 kV ICTs at Subhasgram with peak load of around 800MW at each of these S/Stns. Although Jeerat has 400 kV connectivity with Subhasgram, Fig.No Not in last quarter Jeerat and Kolaghat and Bakreswar besides 1 Peak Hours C1.1 and but was observed in Subhasgra Behrampur via 400 kV single C1.2 earlier quarters m circuit lines, the reactive compensation provided at 132kV and below S/stns is inadequate. During the Peak hrs demand of West Bengal sharply increases causing dip in Jeerat voltage even below 380 kV as there is no adequate reactive power compensation or nearby generator for VAR support. Further to boost 18

voltage of 132KV level West Bengal frequently operates on line Tap changer of its 220/132KV ATRs during peak hours causing further deterioration of voltage profile at 400KV level. Remedial Actions: Installation of appropriate reactive compensation in load side distribution or sub transmission network is expected to help in marinating better voltage profile at these two substations.

1.4 Nodes Experiencing High Voltage NIL

Annexure II.A: Graphs indicating Transmission Line Constraints in Respective Region

400 kV Rangpo-Binaguri D/C, Line Duration Curve Apr-18 May-18 Jun-18 2000

1800

1600

1400

1200

1000 Loading above 800 850 MW Duration upto which line loading is more than 850 MW 600

Loading (MW) Loading Apr '18 : 56 % 400 May '18 : 75 % 200 June '18 : 100 % 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Duration

Figure-A1:- Line Duration curve of 400 kV Rangpo-Binaguri D/C

220kV Ranchi Hatia D/C, Line Duration Curve Apr-18 May-18 Jun-18 500

450

400

350

300

250 Loading above 200 210 MW Duration upto which line loading is more than 210 MW 150

Loading (MW) Loading Apr '18 : 47% 100 May '18 : 77% 50 June '18 : 82% 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Duration

Figure-A2:- Line Duration curve of 220 kV Ranchi-Hatia D/C

220kV Patna-Sipara T/C, Line Duration Curve Apr-18 May-18 Jun-18 600 550 500 450 400 350 300 250 200

Loading (MW) Loading 150 100 50 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Duration Figure-A3-(i):- Line Duration curve of 220 kV Patna-Sipara T/C

220kV Patna-Sipra D/C, Line Duration Curve Apr-18 May-18 Jun-18 400

350

300

250 Loading above 200 210 MW

150 Duration upto which line loading is more than 210 MW

Apr '18 : 50 % 100 Loading (MW) Loading May '18 : 82% 50 June '18 : 93 % 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Duration

Figure-A3-(i):- Line Duration curve of 220 kV Patna-Sipara T/C

Annexure II.B: Graphs indicating ICT Constraints in Respective Region

Figure-B1:- Load Duration curve of Patna ICTs

Figure-B2:- Load Duration curve of Gaya ICTs 22

Figure-B3:- Load Duration curve of Maithon ICTs

Annexure II.C: Graphs Indicating Nodes Experiencing Low Voltage in Eastern Region Voltage duration Curve of 400 kV Jeerat Apr-18 May-18 Jun-18 440

430

420

410

400

Voltage(kV) 390 Duration upto which volatge Duration upto which volatge is more is less than 390 kV than 420 kV 380 Apr '18 : 2% Apr '18 : 9%

370 May '18 :6% May '18 : 6%

June '18 :10% June '18 : 1% 360 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Duration Figure-C1.1:- Voltage duration curve of Jeerat

Voltage Duration Curve of 400 kV Subhasgarm Apr-18 May-18 Jun-18 440

430

420

410

400

390 Voltage (kV) Duration upto which volatge is less Duration upto which volatge is more than 390 kV than 420 kV 380 Apr'18 :4% Apr'18 : 9%

370 May '18 : 11% May '18 : 7%

June '18 : 12% June '18 : 2% 360 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Duration

Figure-C1.2:- Voltage duration curve of Jeerat

Annexure- III

Annexure – IV

Annexure- V