POWER GRID CORPORATION OF INDIA LTD

1. POWER GRID CORPORATION OF INDIA LTD GRID EVENTS AND ISSUES in 139TH SREB MEETING 19TH DECEMBER 2005 HYDERABAD SOUTHERN REGIONAL LOAD DESPATCH CENTRE

2. ISSUES 7.1.1 400 KVKAIGA – GUTTUR 7.2.1400 KV MADURAI – TRIVENDRUM D/C LINE 8.0 TALCHER – KOLAR HVDC 9.1 400 KV KAIGA – NARENDRA D/C LINE 10.0 EVACUATION SCHEMES FOR NEW CENTRAL SECTOR GENERATING STATIONS 11.1 UNREQUISITIONED POWER OF NTPC STATIONS 12.2 KALPAKKAM – EVACUATION SCHEME

3. ISSUES (Continued …) 13.1 TALCHER – KOLAR INTERTRIP SCHEME 14.1ALTERNATE PATH FOR EVACUATION OF TALCHER STAGE 2 POWER 15.1INTER REGIONAL TRANSMISSION LINKS BETWEEN ER/WR AND SR 16.1.i HIGH VOLTAGE CONDITIONS 16.1.ii KAIGA – GUTTUR TRIPPING DETAILS 16.1.iii HIGH FREQUENCY CONDITIONS 16.1.iv STOA – CHIKKODI – KOLHAPUR LINE

4. ISSUES (Continued …) • FREQUENCY LINKED INCENTIVE

5. SCHEDULE DRAWAL GRAPHS • INTER REGIONAL EXCHANGES • SUMMARY OF UI

6. 400 KV KAIGA – GUTTUR DIAGRAM • TRIPPING DETAILS • DURING TRIPPING TYPICAL FLOWS • DIFFERENT OPTIONS • ALTERNATIVE 1 (RADIALISATION OF LOAD) • ALTERNATIVE 2 (SPLIT BUS AT KAIGA) • ALTERNATIVE 3 (INTER TRIP OF LINES FROM KAIGA) • LOAD FLOW STUDY RESULTS FOR • RADIALISATION OF CHIKODI, BELGAUM AND NARENDRA LOAD • PROVIDING AUTOMATIC INTER-TRIP SCHEMES AT KAIGA

7. 400 KV KAIGA GUTTUR D/C LINE KOLHAPUR (MAHARASHTRA) CHIKKODI KARNATAKA M.L.PURA BELGAUM MAPUSA NARENDRA 220 PONDA (Goa) AMBEWADI HUBLI XELDEM(GOA) KODASALLI KADRA NAGJHARI 220 KV CIRCUIT 1 GUTTUR KAIGA Back NOT TO SCALE DISTANCES EXAGERATED FOR CONVENIENCE 400 KV CIRCUIT 2

9. KOLHAPUR (MSEB) ALL FIGURES IN MW PONDA CHIKKODI 44 44 BELGAUM 57 90 90 AMBEWADI NADENDRA 57 101 101 28(-21) MAHALINGPURA (-21)28 HUBLI 101 NAGJHERI KARWAR 500 GADAG 25 387(475) 63 (97)52 1 52(97) 163 SHARAVATHI LINGAPUR (41)11 KODASALLI 150 130 TALAGUPPA 400KV (76) 24 24(76) 48(-13) 220KV KADRA (OPEN) 307 (85) 115 GENERATORS GUTTUR 400 KAIGA 192(304) SUB-STATION PROPOSED ALTERNATIVES FOR AVERTING TRIPPING OF GENERATORS AT KAIGA & KALI COMLEX DURING TRIPPING OF 400KV KAIGA-GUTTUR FEEDER II TYPICAL MW FLOWS:- AROUND KAIGA AND KALI COMPLEX Note: The Figures in brackets shows the flows after tripping of 400KV Kaiga-Guttur ckt II

10. KOLHAPUR (MSEB) ALL FIGURES IN MW PONDA CHIKKODI 44 44 BELGAUM OPEN 90 90 AMBEWADI NADENDRA OPEN 47 47 OPEN MAHALINGPURA OPEN HUBLI 105 NAGJHERI KARWAR 500 GADAG 37 395(520) 43 2 2 11 181 KODASALLI SHARAVATHI LINGAPUR 22 150 TALAGUPPA 130 400KV 109 109 115(24) 220KV KADRA 249 (0) (103)148 GENERATORS GUTTUR 400 KAIGA 179(293) SUB-STATION ALTERNATIVE – I TYPICAL FLOWS :- AFTER RADIALISATION OF CHIKODI, BELGAUM & NARENDRA Note: The Figures in brackets shows the flows after tripping of 400KV Kaiga-Guttur Feeder – II.

11. SECTION - 1 SECTION - 2 NARENDRA 400KV BUS KAIGA 400KV BUS - 2 KAIGA 400KV BUS - 1 60 GUTTUR 400KV BUS 60 KAIGA 220KV BUS 2 KAIGA 220KV 245 BUS 1 20 155 100 400 GUTTUR 220KV BUS KADRA KODASALLY ~ 400KV KAIGA 2 x 220 MW 220KV ~ GENERATOR ICT ALL FIGURES IN MW ALTERNATIVE – 2 TYPICAL FLOWS :- SPLIT BUS OPERATION AT KAIGA Continue …

12. KOLHAPUR (MSEB) ALL FIGURES IN MW PONDA CHIKKODI 43 43 BELGAUM 52 88 88 AMBEWADI NADENDRA 52 98 98 6 MAHALINGPURA 6 HUBLI 103 NAGJHERI KARWAR 500 GADAG 38 430 15 70 70 16 191 KODASALLI SHARAVATHI LINGAPUR 24 150 130 TALAGUPPA 400KV 60 20 60 220KV KADRA 100 245 GENERATORS GUTTUR 400 KAIGA 155 SUB-STATION ALTERNATIVE – 2 (Continued …) TYPICAL FLOWS :- SPLIT BUS OPERATION AT KAIGA

13. KOLHAPUR (MSEB) ALL FIGURES IN MW PONDA CHIKKODI 44 44 BELGAUM 54(64) 90 90 AMBEWADI NADENDRA 54(64) (112)101 101(112) 21(10) MAHALINGPURA (10)21 HUBLI 113 NAGJHERI KARWAR 500 GADAG 60 475(521) 15 (131)97 34 97(131) 217 SHARAVATHI LINGAPUR (125)41 KODASALLI 150 130 TALAGUPPA 400KV (54)76 76(54) 13(OPEN) 220KV KADRA OPEN(OPEN) (OPEN) 85 GENERATORS GUTTUR 400 KAIGA 304(275) SUB-STATION ALTERNATIVE – 3 TYPICAL FLOWS :- AFTER TRIPPING OF 400KV KAIGA-GUTTUR CIRCUIT II Note: The Figures in brackets shows the flows after tripping of 220kV Kaiga-Kaidra & Kaiga-Kodasalli.

16. NLMNG CHITOOR KOLAR HOODY ALMATHI HASSAN SP-BUDUR S’HALLI HOSUR MELKOTTAIYUR MYSORE BAHOOR KOZHIKODE SALEM NEYVELI NLY-EXP ARASUR JAYAMKONDAM PUGALUR THRISSUR UDUMALPET TRICHY KARAIKUDI COCHIN MADURAI MULTI-CIRCUIT TOWER ON 220 KV EDAMON-KAYATHAR CORRIDOR 400 KV MAURAI – TRIVENDRUM D/C LINE TRIVANDRUM

17. ADVANTAGES OF MADURAI-TRIVANDRUM LINE • ALTERNATE SUPPLY PATH TO TRIVANDRUM AREA • INCREASED STABILITY OF S.KERALA SYSTEM • DECREASED LOSSES • IMPROVED TRANSFER MARGIN – FACILITATING BETTER MERIT ORDER OPERATION AND ECONOMY Cont..

18. THE ISSUES OF CONCERN • HIGH VOLTAGE AT TRIVANDRUM During low demand and high monsoon period the high voltage persistant at Trivandrum has been addressed by • opening the 220 KV Edamon – Kayathar line • by opening one of the 400 KV line and increasing the load on the other 400 KV line Presently as the loads have been increased by KSEB, the voltages are within limits. Cont..

20. ADVANTAGES OF COMMISSIONING 400 KV KAIGA NARENDRA D/C LINE KOLHAPUR (MAHARASHTRA) CHIKKODI KARNATAKA M.L.PURA BELGAUM MAPUSA NARENDRA 220 PONDA (Goa) AMBEWADI HUBLI XELDEM(GOA) KODASALLI KADRA NAGJHARI 220 KV CIRCUIT 1 GUTTUR KAIGA Next NOT TO SCALE DISTANCES EXAGERATED FOR CONVENIENCE 400 KV CIRCUIT 2

21. ADVANTAGES OF COMMISSIONING 400 KV KAIGA-NARENDRA D/C LINE • PROVIDES ALTERNATE PATH FOR EVACUATION OF KAIGA GENERATION IN CASE OF CONTINGENCY • LINE IS ON DIFFERENT ROUTE FROM THAT OF KAIGA-GUTTUR • ENHANCED REDUNDANCY AND RELIABILITY

22. HIGH FREQUENCY CONDITIONSINSOUTHERN REGIONAL GRID

23. FREQUENCY PROFILE DURING THE MONTHS SEPTEMBER, OCTOBER, NOVEMBER 2005 LAST YEAR COMPARISON TYPICAL HIGH FREQUENCY TREND Cont..

24. Issues Of Concern • Wastage of Resources • Grid Insecurity • High Frequency also Causes High Voltage • Damage to the Equipments Cont..

25. ACTIONS TO BE TAKEN TO ARREST HIGH FREQUENCY: • Reservoir based hydro backing/closing • Liquid Fuel Stations backing/closing down • Inter Regional Export • Thermal Stations to back down/Close down • Hydro Stations to back down – even on overflowing stations With frequency > 50.5 Hz • back down even at overflowing hydro stations No sudden injection in the grid at freq > 50.2 Hz. Cont..

26. KADAMPARAI GENERATION/PUMP ENERGY FROM JAN - 2003 Details

27. FREQUENCY CURVE FOR 24th NOV 2005 FVI = 1.26 Avg Freq = 50.22Hz MAXIMUM FVI BACK

28. HIGH VOLTAGE CONDITIONSINSOUTHERN REGIONAL GRID

29. VARIATION OF MAXIMUM VOLTAGES IN SR GRID DURING NOV 2005

30. 2 Lines Kept Open > 98% of Time 7 Lines Kept Open > 75% of Time 14 Lines Kept Open > 50% of Time 23 Lines Kept Open > 20% of Time

31. STATUS OF 400 KV LINES OF SR AS ON DATE 02-NOV-05 TALCHER ORISSA BHADRAVATI JEYPORE MAHARASHTRA AP SIMHADRI NTPC RSTPP KALPAKKA P KHAMMAM GAZUWAKA (POWERGRID) MMDP HYDERABAD P P P MAHABOOB NAGAR P VIJAYAWADA N’SAGAR NARENDRA RAICHUR P KAR KURNOOL MUNIRABAD SSLMM 41 NO.s 400 KV LINES OPENED TO CONTAIN HIGH VOLTAGE P KAIGA SIRSI GOOTY P N CUDDAPAH P 1000 MW HVDC BACK TO BACK LINK GUTTUR NELLORE HIRIYUR TALGUPPA 2000 MW HVDC BIPOLE NELAMANGALA BANGALORE MADRAS P P KOLAR HOODY HOSUR 500 KV HVDC LINE 400 KV LINE POWERGRID SALEM NEYVELI 400 KV LINE APTRANSCO TN NEYVELI TPS – 1 (EXP) EXP 400 KV LINE KPTCL UDUMALPET P TRICHY TRICHUR P 400 KV LINE OPERATED AT 220 KV MADURAI THERMAL GENERATING STATION KER List 400KV SUB-STATION Cont.. THIRUVANANTHAPURAM

32. Actions Already Taken • TAKING OUT THE LINE AND CONVERTING LINE REACTOR TO BUS REACTOR • MVAR ABSORPTION BY GENERATING UNITS • TRANSFORMER TAP CHANGES MANY ICT TAPS WERE CHANGED ON 400/220 ICT’s • GT TAP CHANGES • OPENING UP OF LIGHTLY LOADED REDUNDANT TIE LINES • UTILISATION OF HYBRID AC/DC NETWORK DIVERSION OF TALCHER STAGE 2 POWER THROUGH GAJUWAKA

33. Issues Of Concern • Frequent switching in/out of Lines • Resulting wear and tear of equipments • Continuous High Voltage • Resulting damage to the equipments • Network Redundancy is lost causing Security concerns • Increase in Regional system losses

34. Desired Actions • ABSORPTION OF VARS BY ALL THE OPERATING UNITS WITHIN THEIR CAPABILITY CURVES • OPENING OF 220 KV AND BELOW LEVEL LIGHTLY LOADED LINES IN SATES • GENERATORS ON SYNCH CONDENSOR MODE • TO CARRY OUT DETAILED STUDIES TO FIND OUT REQUIREMENT OF ADDITIONAL REACTORS AT SUITABLE LOCATIONS

36. SYNCHRONOUS CONDENSOR OPERATION: IN OPERATION Cont..

37. LIST OF GENERATORS WITH PELTON TURBINE Cont..

38. 3 QUADRANT OPERATION MW MVAR Cont..

39. MW MVAR Cont..

40. GENERATORS ON SYNCH CONDENSOR MODE: ADVANTAGES • IMPROVED SHORT CIRCUIT LEVELS • CAN BE CONVERTED TO GENERATOR MODE IN SHORT NOTICE • EXCELLENT REACTIVE SOURCE • REDUCED LOSSES • CONTROL VOLTAGE FLUCTUATIONS

41. SCHEDULE 1 OF ABT ORDER DATED 04-01-2000 Para 8 (ii) The beneficiaries will have full freedom for negotiating any transaction for utilisation of their capacity shares. In such cases, the beneficiary having allocation in the capacity of the generating station will be liable for full payment of capacity charges and energy charges (including that for sale of power under the transactions negotiated by them) for all its scheduled and unscheduled transactions from its capacity share. (iii) If there is any capacity which remains un-requisitioned during day-to-day operation, RLDC, shall advise all beneficiaries in the region and the other RLDCs so that such capacity may be requisitioned through bilateral arrangements with the concerned generating company/beneficiary(ies) under intimation to the RLDC. Cont..

42. CLAUSE 5.7.3 FROM THE EXTRACTS OF ABT ORDER DATED 04-01-2000 While on the subject of trading, the Commission anticipates an emerging situation of a surplus on account of the gap between the availability and scheduled generation. This power could go unutilised as the capacity for this generation is blocked because the capacity charges are borne by the beneficiary’ states. In order to economise operations, it would be appropriate to make use of this power on firm or non-firm basis with a suitable understanding between the beneficiary states and the generator. It is therefore suggested that the generating company may initiate a dialogue with the beneficiary states for making use of this power for which the terms could be negotiated by themselves. Though, strictly speaking, this tariff also falls within the jurisdiction of the Commission, due to the short term nature of this transaction the tariff could be freed to be negotiated for which a general exemption could be taken from the Commission. This would provide substantial additional revenue to the generator if he goes about aggressively marketing this surplus power. Cont..

43. FINAL REGULATIONS:TERMS&CONDITIONS OF TARIFF 26 MAR 2004PARA-30. Billing and Payment of Capacity Charges: (ii) The beneficiaries shall have full freedom for negotiating any transaction for utilisation of their capacity shares. In such cases, the beneficiary having allocation in the capacity of the generating station shall be liable for full payment of capacity charges and energy charges (including that for sale of power under the transaction negotiated by him) corresponding to his total allocation and schedule respectively. (iii) If any capacity remains un-requisitioned during day-to-day operation, the Regional Load Despatch Centre shall advise all beneficiaries in the region and the other Regional Load Despatch Centres so that such capacity may be requisitioned through bilateral arrangements either with the concerned generating company or with the concerned beneficiary(ies) under intimation to the Regional Load Despatch Centre. The information regarding un-requisitioned capacity shall also be made available by the Regional Load Despatch Centres through their respective websites.

44. UNREQUISITIONED POWER OF NTPC STATIONS • RSTPS UNIT 7 • SEP 05 1.12 MU ( 05 Transactions) • OCT 05 7.65 MU (15 Transactions) • NOV 05 4.37 MU (11 Transactions) • TALCHER STAGE 2 • NOV 05 6.06 MU (08 Transactions) DETAILS DETAILS Cont..

45. Cont..

47. EVACUATION SCHEMES FOR NEW CENTRAL SECTOR GENERATING STATIONS • KOODANKULAM APP SPS FOR KOODANKULAM APP • NEYVELI TS-II EXPANSION • KAIGA STAGE -II

48. KUDANKULAM TRANSMISSION SYSTEM( 2000MW) LINES : 601+ 350 = 950 Km. ESTIMATED COST = 1710 CRORES • KUDANKULAM-TIRUNELVELI 2 X 400 KV D/C LINES WITH QUAD (108 & 83 Km.) KARNATAKA • TIRUNELVELI-UDUMALPET D/C LINE WITH TWIN MOOSE (300Km) T N KERALA • LILO OF BOTH CIRCUITS OF MADURAI-TRIVANDRUM LINE AT TIRUNELVELI ( 2 X 55 Km) • EDAMON-MUVATTUPUZHA D/C LINE QUAD (150Km) • TIRUNELVELI-EDAMON 400KV D/C LINE (110Km). • MUVATTUPUZHA-TRICHUR 400KV D/C LINE WITH QUAD CONDUCTORS (90Km) Contd..

49. KUDANKULAM TRANSMISSION SYSTEM( 2000MW) SUB-STATIONS • NEW 400/220KV SUBSTATIONS AT TIRUNELVELI, MUVATTUPUZHA • AUGMENTATION OF TRANSFORMATION CAPACITY BY ONE TRANSFORMER EACH AT UDUMALPET & TRIVANDRUM S/S SUPPLEMENTARY TRANSMISSION SYSTEM • LILO OF ONE CIRCUIT OF 400KV MADURAI-TRICHY • AT KARAIKUDI ( 60 Km) ALONG WITH SUBSTATION AT • KARAIKUDI (TAMILNADU) • LILO OF ONE CIRCUIT OF TALAGUPPA-NELAMANGALA • 400KV LINE AT HASSAN ( 80 KM) ALONG WITH SUBSTATION AT • HASSAN.(KARNATAKA)

50. KAIGA 3 & 4 TRANSMISSION SYSTEM COST ESTIMATE : 512 CRORES LINES : 413 Kms • MYSORE-KOZHIKODE D/C LINE • LILO OF KOLAR-SRIPERUMBADUR AT MELAKOTTAIYUR (40KM) • NARENDRA-DAVANGERE D/C LINE SUB-STATION : 2 Nos. New K E R A L A • NEW 400/220KV SUBSTATION AT KOZHIKODE & MELAKOTTAIYUR • 2ND 315MVA TRANSFORMER AT HIRIYUR S/S. • BAY EXTENSION AT NARENDRA, DAVANGERE (KPTCL) & • HIRIYUR.