1. OPEN ACCESS EXPERIENCES and WAY AHEAD N.R.C BABU CHIEF MANAGER (MO), SRLDC, POWERGRID 10.08.2009

2. Open Access in Transmission:   Why and What ? Why and What ?   Journey … Journey …   Success Story… Success Story…   Issues… Issues…   Way Ahead… Way Ahead…

3. INSTALLED CAPACITY NORTHERN :- 38,726 MW EASTERN :- 20,815 MW SOUTHERN :- 42,377 MW WESTERN :- 46,348 MW NORTH-EASTERN :- 2,256 MW TOTAL 150,519 MW SOUTHERN REGION WESTERN REGION EASTERN REGION NORTHERN REGION NORTH- EASTERN REGION REGIONAL GRIDS

4. Coal Hydro Energy Resource Map

5. Source: Powerline (Siemens Ad), Oct-2006 HYDRO RESOURCES COAL BELT MUMBAI DELHI CHENNAIBANGALORE KOLKATTA Resources are far away from Load centers. Necessitates Long Transmission links for evacuation AREAS SHOWN ARE APPROXIMATE AND INDICATIVE Spatial Distribution Of Load

6. Diversity details of Regional Grids in India REGIONREMARKS Northern RegionDeficit Region Highly weather sensitive load North Eastern RegionVery low load High hydro potential Eastern RegionLow load High coal reserves Pit head base load plants Western RegionIndustrial load and agricultural load Highly Deficit Region Southern RegionHigh load (40% agricultural load) Monsoon dependent hydro

7. A strong transmission network backbone is essential in order to transfer the power across the length and breadth of the country : - Due to high load growth and low generation avenues in Northern and Western Regions - Due to low load and high generation in Eastern and North Eastern regions - Due to high load growth and monsoon dependent generation availability in Southern Region Necessity for strong transmission backbone …

8. Milestones 1989 Unbundling of CS transmission from generation - (Formation of National Power Transmission Corporation.. now POWERGRID) - (Formation of National Power Transmission Corporation.. now POWERGRID) 1991 Generation opened to Private Sector 1995 Unbundling process started in States - State unbundled into Gencos, Transco & Discom - State unbundled into Gencos, Transco & Discom 1998 Electricity (Amendment) Act 1998 1998 Electricity Regulatory Commission Act passed 2003 Electricity Act 2003 enacted in June 2003 2004 CERC Order and Regulations on OPEN ACCESS

9. Open Access: Definition As per Electricity Act, 2003 Section 2 (47) “Open access” means the non-discriminatory provision for the use of transmission lines or distribution system or associated facilities with such lines or system by any licensee or consumer or a person engaged in generation in accordance with the regulations specified by the Appropriate Commission;”

10. A More general Definition of “Open Access” “Enabling of non-discriminatory sale/ purchase of electric power/energy between two parties utilizing the system of an in- between (third party), and not blocking it on unreasonable grounds”

11. Scope/Applicability… Subject to any other regulations specified by the Commission, the long-term customer shall have first priority for using the inter-State transmission system for the designated use. These Regulations shall apply for utilization of surplus capacity available thereafter on the inter-State transmission system by virtue of- (a) Inherent design margins; (b) Margins available due to variations in power flows; (c ) Margins available due to in-built spare transmission capacity created to cater to future load growth or generation addition: As per CERC Regulations 2008 Clause 3

12. Agencies involved in Short-Term Open Access Transaction RLDC (s) SLDC (s) CTU STU (s) Buyer Seller Trader Power Exchanges

13. OPEN ACCESS : OPEN ACCESS : JOURNEY... JOURNEY...

14. Open Access in ISTS: Journey… CERC Regulations on Open Access in Inter State Transmission implemented w.e.f. 6-May-2004. CERC amended the above Regulations and the amended Regulations implemented w.e.f 01-04-2005. CERC on 25-01-2008 amended the Regulations and the new Regulations are implemented w.e.f 01-04-2008. CERC on 20.05.2009 amended the Regulations and the new Regulations are implemented w.e.f 15.06.2009

15. Open Access in ISTS: Journey… Long Term : Twenty five years and above Long Term : Twenty five years and above - Life of the Assets about 25 years - Life of the Assets about 25 years - Existing beneficiaries of a regional transmission system owned or operated by CTU- deemed long term customers - Existing beneficiaries of a regional transmission system owned or operated by CTU- deemed long term customers - New Long Term Open Access customers: Require BPTA for inter-State transmission - New Long Term Open Access customers: Require BPTA for inter-State transmission Short Term : Which is not Long Term Short Term : Which is not Long Term - Essentially a Non firm service - Essentially a Non firm service - The service may be curtailed if system security demands.

16. Effective 01.04.2008 Regulations cover only Short-term Open Access Transactions categorized as - Bilateral - Collective (through PX) Earlier Products of Short-Term retained under Bilateral Transactions Nodal Agency - Bilateral : RLDCs - Collective : NLDC Open Access in ISTS: Journey… CERC OA Regulations 2008

17. Open Access in ISTS: Journey… Products – Short term Access - Advance - First Come First Serve - Day ahead - Contingency CERC OA Regulations 2008 Provisions relating to Long Term as per the Open Access Regulations, 2004 to continue, till CERC further notifies. Long term Access

18. Both Buyers and Sellers of Collective transactions to bear transmission charges and absorb transmission losses Inter-Regional links -No Separate treatment. Emphasis on “Scheduling” rather than “Reservation” SLDC consent mandated along with application In case of Congestion – e-Bidding without Price Cap Exit Option provided with payment of up to 2 days open access charges. Moving towards empowerment of SLDCs Open Access in ISTS: Journey… CERC OA Regulations 2009

19. STOA CASE STOA CASE APTRANSCO to MPSEB 100 MW for One day from 0000 to 0600 hrs.

20. APTRANSCO - MPSEB THROUGH NVVNL (0000 HRS – 0600 HRS) 100 MW AT INJECTION POINT INJECTING UTILITY APTRANSCO CUSTOMER: NVVNL DRAWEE UTILITY MPSEB CAPACITY APPROVED 100 MW DAILY PERIOD 0000-0600HRS AP WR GRID MP HVDC BACK TO BACK AT BHADRWATHI IN WR INTERVENING REGIONAL LINK 1.SR-WR TRADER: NVVNL

21. APTRANSCO - MPSEB THROUGH NVVNL (0000 HRS – 0600 HRS) 100 MW AT INJECTION POINT EXPORT AT AP 100 MW AT SR PERIPHERY 96.9 MW MP RECIEVES 93.0 MW LOSSES IN SR 3.12% LOSSES IN WR 4% TOTAL LOSSES FOR TRANSACTION 7.0 MW AP WR GRID MP HVDC BACK TO BACK AT BHADRWATHI IN WR CTU

22. APTRANSCO - MPSEB THROUGH NVVNL (0000 HRS – 0600 HRS) 100 MW AT INJECTION POINT APPLICATION PROCESSING FEE Rs 5000 PER TRANSACTION TRANSMISSION CHARGES PER MW PER DAY 1.Rs 700.91FOR CTU-SR 2.Rs 881.49FOR SR-WR LINK 3.Rs 339.98FOR CTU-WR TOTAL TRANSMISSION CHARGE PER UNIT 34.53Ps/. SCHEDULING CHARGES PER DAY 1.Rs 3000FOR SRLDC 2.Rs 3000FOR WRLDC AP WR GRID MP HVDC BACK TO BACK AT BHADRWATHI IN WR Payments as per Regulation 2004 of CERC ST Rate - in Rs/MW/Day - Min. Charges for one day

23. APTRANSCO - MPSEB THROUGH NVVNL (0000 HRS – 0600 HRS) 100 MW AT INJECTION POINT APPLICATION PROCESSING FEE Rs 5000 PER TRANSACTION TRANSMISSION CHARGES PER MW PER DAY 1.Rs 700.91FOR CTU-SR 2.Rs 881.49FOR SR-WR LINK 3.Rs 339.98FOR CTU-WR TOTAL TRANSMISSION CHARGE PER UNIT 13.52Ps /. SCHEDULING CHARGES PER DAY 1.Rs 3000FOR SRLDC 2.Rs 3000FOR WRLDC AP WR GRID MP HVDC BACK TO BACK AT BHADRWATHI IN WR Payments as per Regulation 2004 Amendment 2005) of CERC ST Rate - in Rs/MW/Day, - Charges as per continuous block of up to 6 hours, 12 hours, and more than 12 hours

24. APTRANSCO - MPSEB THROUGH NVVNL (0000 HRS – 0600 HRS) 100 MW AT INJECTION POINT APPLICATION PROCESSING FEE Rs 5000 PER TRANSACTION TRANSMISSION CHARGES 1.Rs 60 /MWH FOR WHEELING TOTAL TRANSMISSION CHARGE PER UNIT 7.83Ps/. SCHEDULING CHARGES PER DAY 1.Rs 2000FOR SRLDC 2.Rs 2000FOR WRLDC AP WR GRID MP HVDC BACK TO BACK AT BHADRWATHI IN WR Payments as per Regulation 2008 of CERC

25. Comparison of CERC Regulations on Short-Term Open Access (Regulation 2004, Amendment 2005 and Regulations 2008) Old Regulations Old Regulations (06.05.2004 to 31.03.2005) Amended Regulations Amended Regulations (w.e.f. 01.04.2005 to (w.e.f. 01.04.2005 to 31.03.2008) 31.03.2008) Regulations, 2008 (w.e.f. 01.04.2008) Total STOA Charges Paisa/Unit 34.53 Total STOA Charges Paisa/Unit 13.52 Total STOA Charges Paisa/Unit 7.83 Regulations, 2009 (w.e.f. 15.06.2009) 18.29Total STOA Charges Paisa/Unit 18.29 DETAILEDCASE STUDIES.ppt

26. OPEN ACCESS : SUCCESS STORY…

27. 2800 MW 6200 MW 1700MW 2500MW 1100 MW 2100 MW 38,018 MW 20,516 44,043 MW 2255 1250 MW IR Capacity=15,450 MW ( Till Sep 2009 = 17,650 MW) Name of the Link Capacity(MW)East-North Pusauli-Sahupuri 220kV S/c 100 Sasaram HVDC back-to-back 500 Muzaffarpur-Gorakhpur 400kV D/c (Quad) 2000 Bihar Sharif-Balia 400kV D/c (Quad) 1200 Patna-Balia 400kV D/c (Quad) 1200 Sub-Total5000 East-West Budhipadar-Korba 220kV T/c 400 Rourkela-Raipur 400kV D/c 1400 Sub-Total1800 West-North Vindhyachal HVDC back-to-back 500 Existing 220kV AC Lines 500 Gwalior-Agra 765kV S/c 1100 Sub-Total2100 East-South Gazuwaka HVDC back-to-back 1000 Existing 220kV AC Lines 100 Talcher-Kolar HVDC bipole (Enhanced) 2500 Sub-Total3600 West-South Chandrapur HVDC back-to-back 1000 Other lines 700 Sub-Total1700 East-North East Bongaigaon-Siliguri 400kV D/c 1000 Birpara-Salakati 220kV D/c 250 Sub-Total1250 Total15450 39,656 MW IR LINKS CAPACITY ER-NR 400 kV Barh-Balia D/C: 1200 MW ER-WR 400 kV Ranchi-Sipat D/C: 1000 MW Linked with Barh Project

28. EASTERN REGION SOUTHERN REGION WESTERN REGION NORTHERN REGION NORTH- EASTERN REGION ALL INDIA ATC ER ATC = 800 MW ATC = 750 MW ATC = 950 MW ATC = 1375 MW ATC = 1395 MW ATC = 474 MW ATC =226 MW ATC = 920 MW ATC = 900 MW (Figure shown are for April-2008) What Is ATC

29. 12650 MW 3250 MW 7250 MW 5000 MW 2700 MW 3650 MW 37,700 MW OF INTER- REGIONAL POWER BY 2012 EASTERN REGION SOUTHERN REGION WESTERN REGION NORTHERN REGION NORTH- EASTERN REGION INTER-REGIONAL TRANSFER BY END OF 11 th PLAN (2012) 3000 MW

30. All India basis

33. AT A GLANCE 2008 – 2009 EXPORT IMPORT AT A GLANCE 2009 – 2010 IMPORT

34. Open Access – Success Story Applications Processed (Since Beginning) > 20,000 No. Volume (Approved Energy) (Since Beginning) > 90BUs Applications Approved > 95 % Refusal/Non-consent by SLDCs > 3 - 4% Refusal due to system constraints < 0.5 %

35. Open Access – Success Story Transactions between extreme corners of the country RGCCPP ( Kayamkulam) to PSEB Arunachal Pradesh(NER) to PSEB TNEB to J&K Large number of Captive Generating plants used STOA and helped in enhancing the power availability in grid. Ugar Sugars (KAR) - JAIPUR (RAJASTHAN) Godavari Sugars (KAR) - MSEDCL NCS Sugar(ANDHARA) – GUVNL Indorama ( MAH) – APPCC ( ANDHRA) MORE DETAILS

36. Open Access – Success Story Even costly power was harnessed to meet the high demand RGCCPP ( Kayamkulam) (NAPTHA) to PSEB BSES(KERALA) (DIESEL) to NDMC (DELHI) Diversity being gainfully utilised by Market players under STOA Delhi/TNEB Export in night ; Import during evening peak ANDHRA Export during evening peak ; Import in night Generators PLF has also increased. Kayamkulam GPS - (From 57 % in 2006-07 to 82 % in 2007-08- 82%)

37. OPEN ACCESS : ISSUES…

38. Open Access - Issues Skewed load – generation pattern Constrained Transmission Network under certain conditions Consents by STU/SLDC for injection of power by embedded customers Telemetry Metering Scheduling PPAs

39. Open Access - Issues UI Settlement of Intra state entities - - Before the Implementation of Open Access Regulations 2008, for deviations different STU/SLDCs are charging differently for embedded customers. - - At times even the clearance was being withheld for want of approval philosophy. In the New Open Access Regulations the issues are being addressed

40. OPEN ACCESS : WAY AHEAD…

41. Open Access- Way Ahead… Empowerment of SLDCs Intra State ABT Power Exchanges (Pxs) Easy and workable solutions to tap micro/mini Non conventional Energy Resources

42. Open Access- Way Ahead… Empowerment of SLDCs - Greater role assigned to State Load Despatch Centre (SLDC) to bring them at par with the Regional Load Despatch Centre (RLDC). - unless specified otherwise by the concerned State Commission, the UI rate for intra-State entity shall be 105% (for over-drawals/under generation) and 95% (for under-drawals / over generation) of the UI Rate at the periphery of regional entity. This has been done to facilitate dispute free energy accounting and settlement of deviations for intra-state entities located in the State where intra-state ABT has not yet been implemented. - Empowerment of SLDCs has been made technically and financially.

43. 11/11/2015POWERGRID43 ISGS: Inter State Generating Stations SGS: State Generating Stations CTU: Central Transmission Utility STU: State Transmission Utility Inter-State ABT Intra-State ABT

44. FURTHER IMPROVEMENT: INTRA-STATE ABT METERING COMMERCIAL INCENTIVES OPEN-ACCESS VAR MANAGEMENT GENCOS PARTICIPATION DISCOMS SCHEDULES

45. Open Access- Way Ahead… A Power exchange facilitates equitable, transparent and efficient trading of power. Bridges the demand supply mismatch by bringing larger players together for buying and selling in an auction based system. While maintaining complete anonymity, resolves the constraints in the earlier formats, Viz. search costs, asymmetric information, transaction costs, and counter-party risks.

46. Open Access- Way Ahead… “collective transaction” means a set of transactions discovered in power exchange Scheduling and open access for collective transactions discovered in a power exchange through anonymous simultaneous competitive bidding by buyers and sellers, presently on day-ahead basis.

47. Open Access- Way Ahead… The ATC declaration is to be done by NLDC on its web site every day. Depending on the corridor availabilities the solution is to be found out and the allowed trades will be intimated to NLDC. If there is no congestion NLDC will accept the trades and issue the schedules to the power exchange and the same will be implemented in RLDC schedules. In Power Exchange transactions both buyer and seller have to pay the Transmission and operating charges separately. The transmission losses also have to be borne by the buyer and seller separately.

48. Typical Approvals- Captive Power Plants Typical Approvals- Captive Power Plants Captive Power PlantQuantum( MW) Eastern Region NBVL(OPTCL)27 SAIL-DSP(DVC)20 TISCO(DVC)60 Bhushan Steel25 J.P Cement (Rewa)5 Western Region Indo Rama synthetics22 PSKL10-30 Southern Region Renuka Sugar25 Vishwanath Sugar7.5 Godavari Sugar25 Ugar Sugar25 Jindal Steel200 Nav Bharat50 NCS Sugar13 Back

49. TYPICAL STOA CASE TYPICAL STOA CASE KAYAMKULAM RGCCPP, NTPC to PSEB 150 MW for 31 days on Round the Clock basis

50. SR STOA OF KSEB(RGCCPP) - PSEB 0000 HRS – 2400 HRS 150MW AT RGCCPP EXBUS POINT for 31 days KERALA INJECTING UTILITY RGCCPP,KSEB TRADER: NVVNL KAYAMKULAM RGCCPP NTPC) DRAWEE UTILITYPSEB CAPACITY APPROVED 150 MW DAILY PERIOD 0000-2400 HRS CUSTOMER: NVVNL WR NR PSEB HVDC BACK TO BACK AT VINDHYACHAL IN WR HVDC BACK TO BACK AT BHADRWATHI IN WR INTERVENING REGION WR INTERVENING REGIONAL LINK SR-WR WR-NR INTERVENING STATE TRANSMISSION UTILITYKSEB

51. SR STOA OF KSEB(RGCCPP) - PSEB 0000 HRS – 2400 HRS 150MW AT RGCCPP EXBUS POINT for 31 days KERALA KAYAMKULAM RGCCPP(NTPC) WR NR PSEB HVDC BACK TO BACK AT VINDHYACHAL IN WR HVDC BACK TO BACK AT BHADRWATHI IN WR EXPORT AT RGCCPP BUS150 MW PSEB RECIEVES 134.4 MW AT KERALA PERIPHERY 148.9 MW LOSSES IN KERALA 0.75% LOSSES IN SR 3.12% AT SR-WR PERIPHERY 144.3 MW LOSSES IN WR 4.0% AT WR-NR PERIPHERY 138.5 MW LOSSES IN NR 3.0%

52. SR STOA OF KSEB(RGCCPP) - PSEB 0000 HRS – 2400 HRS 150MW AT RGCCPP EXBUS POINT for 31 days KERALA KAYAMKULAM RGCCPP(NTPC) WR NR PSEB HVDC BACK TO BACK AT VINDHYACHAL IN WR HVDC BACK TO BACK AT BHADRWATHI IN WR APPLICATION PROCESSING FEE Rs 5000 PER TRANSACTION TRANSMISSION CHARGES PER MW PER DAY 1.Rs 700.91FOR CTU-SR 2.Rs 881.49FOR SR-WR LINK 3.Rs 339.98FOR CTU-WR 4.Rs 233.32FOR WR-NR LINK 5.Rs 649.86 FOR CTU-NR 6.Rs 672.07 FOR KSEB SCHEDULING CHARGES PER DAY 1.Rs 3000FOR SRLDC 2.Rs 3000FOR WRLDC 3.Rs 3000FOR NRLDC 4.Rs 3000FOR KSEB TOTAL TRANSMISSION CHARGES PER UNIT 15.12Ps Payments as per Regulation 2004 of CERC

53. SR KERALA KAYAMKULAM RGCCPP(NTPC) WR NR HVDC BACK TO BACK AT VINDHYACHAL IN WR HVDC BACK TO BACK AT BHADRWATHI IN WR APPLICATION PROCESSING FEE Rs 5000 PER TRANSACTION TRANSMISSION CHARGES PER MW PER DAY 1.Rs 843FOR CTU-SR 2.Rs 1311FOR SR-WR LINK 3.Rs 357FOR CTU-WR 4.Rs 600FOR WR-NR LINK 5.Rs 594 FOR CTU-NR 6.Rs 672.07 FOR KSEB SCHEDULING CHARGES PER DAY 1.Rs 3000FOR SRLDC 2.Rs 3000FOR WRLDC 3.Rs 3000FOR NRLDC 4.Rs 1000FOR KSEB TOTAL TRANSMISSION CHARGES PER UNIT 18.5Ps Payments as per Regulation 2004 Amendment 2005) of CERC STOA OF KSEB(RGCCPP) - PSEB 0000 HRS – 2400 HRS 150MW AT RGCCPP EXBUS POINT for 31 days PSEB

54. SR KERALA KAYAMKULAM RGCCPP(NTPC) WR NR PSEB HVDC BACK TO BACK AT VINDHYACHAL IN WR HVDC BACK TO BACK AT BHADRWATHI IN WR APPLICATION PROCESSING FEE Rs 5000 PER TRANSACTION TRANSMISSION CHARGES PER MWHR 1.Rs 90FOR Bilateral Wheeling through one or more region 1.Rs 30 FOR KSEB SCHEDULING CHARGES PER DAY 1.Rs 2000FOR SRLDC 2.Rs 2000FOR WRLDC 3.Rs 2000FOR NRLDC 4.Rs 2000FOR KSEB TOTAL TRANSMISSION CHARGES PER UNIT 12.2Ps STOA OF KSEB(RGCCPP) - PSEB 0000 HRS – 2400 HRS 150MW AT RGCCPP EXBUS POINT for 31 days Payments as per Regulation 2008 of CERC

55. Comparison of CERC Regulations on Short-Term Open Access (Regulation 2004, Amendment 2005 and Regulations 2008) Old Regulations (06.05.2004 to 31.03.2005) Amended Regulations (w.e.f. 01.04.2005 to 31.03.2008) Regulations, 2008 (w.e.f. 01.04.2008) Total STOA Charges Paisa/Unit 15.12 Total STOA Charges Paisa/Unit 18.5 Total STOA Charges Paisa/Unit 12.2 Back

56. STOA OF NBVL(ORISSA) - APPCC (0000 – 2400 HRS ) 50 MW AT INJECTION POINT FROM 01.03.08 to 31.03.08 ORISSA SR CTU HVDC BACK TO BACK AT GAZUWAKA IN SR ER EXPORT AT NBVL(ORISSA)50 MW AT ER-SR PERIPHERY 47.05 MW LOSSES IN ER 3% LOSSES IN SR 3.12% TOTAL LOSSES FOR TRANSACTION 4.42 MW APPCC RECEIVES 45.58 MW ANDHRA PRADESH LOSSES IN OPTCL SYSTEM 3% AT ER PERIPHERY 48.50 MW NBVL

57. NAVABHARAT(NBVL) (ORISSA)(ER) to APPCC (ANDHRA)(SR) 50 MW for 31 days on Round the Clock basis Consent was not given by OPTCL by citing the following Reasons As per provision under chapter 4.11,10.5 of OGC Rule 2006 and order dated 29.10.2007 passed by Hon’ble OERC, the real time data of the CGP,(M/s NBVL) is yet to be received at the SLDC, Control Room. In absence of real time data monitoring facility, SLDC cannot comply the OGC provision under chapter 3.4(9) during contingency condition. Due to the above reasons the Request for Consent is not accepted.

58. NAVABHARAT(NBVL) (ORISSA)(ER) to APPCC (ANDHRA)(SR) 50 MW for 31 days on Round the Clock basis 4.10 Data and Communication Facilities Reliable and efficient speech and data communication systems shall be provided to facilitate necessary communication and data exchange, and supervision/control of the grid by the RLDC, under normal and abnormal conditions. All agencies shall provide Systems to telemeter power system parameter such as flow, voltage and status of switches/transformer taps etc. in line with interface requirements and other guideline made available to RLDC / SLDC. The associated communication system to facilitate data flow up to RLDC/SLDC, as the case may be, shall also be established by the concerned agency as specified by CTU in connection agreement. All agencies in coordination with CTU shall provide the required facilities at their respective ends and RLDC / SLDC as specified in the connection agreement. FROM IEGC CLUASE 4.10

59. NAVABHARAT(NBVL) (ORISSA)(ER) to APPCC (ANDHRA)(SR) 50 MW for 31 days on Round the Clock basis Though the Parties have approached CERC, but the open access transaction is not through.

60. Consent was not given by KPTCL by citing the following Reasons The Sugar companies started trading of the surplus power by applying through open access. But initially KPTCL has not consented by citing the reason that the sugar companies are having PPA with ESCOMs. Later the Sugar companies have approached CERC and CERC allowed them to trade under open access. Aggreived by the order of CERC, KPTCL has approached the Appellate Tribunal. The Tribunal stated that if any petition is filed, the state commission shall consider the same. But the existing open access arrangement to continue.

61. Total Transfer Capability: TTC Voltage Limit Thermal Limit Stability Limit Total Transfer Capability Total Transfer Capability is the minimum of the Thermal Limit, Voltage Limit and the Stability Limit Time Power Flow

62. Total & Available Transfer Capability ATC = TTC – RM Reliability Margin (RM) Long Term Open Access (LTOA) Short Term Open Access (STOA) TTC ATC

63. SKEWED LOAD-GENERATION PATTERN SR FREQUENCY ‘NEW’ GRID FREQUENCY STOA FROM ‘NEW’ GRID ON 17.04.09