System Operations through National & Regional Load Dispatch Centres

1. System Operations through National & Regional Load Dispatch Centres 2nd Interactive Workshop on ‘Transmission & Distribution’ 17th-18th April 2009 at Hotel Sahara Star, Nr. Domestic Airport, Mumbai Organized by India-Tech Foundation

2. Overview of Indian Power System System Operation Power Market Transfer Capability Open Access in Inter-state transmission Congestion Management Challenges and Concerns Outline

3. August 2006 North synchronized With Central Grid Five Regional Grids Two Frequencies March 2003 West synchronized With East & Northeast NEW Grid October 1991 East and Northeast synchronized South Grid Central Grid MERGING OF MARKETS North East West Northeast South Installed Capacity 147 GW Five Regional Grids Five Frequencies

4. Renewable Energy : Wind Power India: 5th Largest Wind Power Producer Total Renewable Energy Sources ~ 13 GW Wind Installed Capacity ~ 9 GW Estimated Wind Potential ~ 45 GW

5. Growth in Inter-regional Transmission Capacity Source: CEA IR CAPACITY : 20800 MW

6. Growth of IR Exchanges

7. Development of Load Despatch Centres Initial stages a telephone/hotline communication system and a frequency meter Operational only during day-time Acted mainly as an information centre State grid interconnections 24x7 operation Rudimentary data acquisition systems Central Sector generating stations Interstate scheduling and energy accounting Regional Grid formation & CTU Modernization of control centres Availability Based Tariff 15-minute scheduling, metering settlement Market operation

8. Modernization of Control Centres 33 SLDCs, 5 RLDCs, 1 NLDC Round-the-clock manning Wideband speech and data communication Fish as well as bird eye view through SCADA Common database in SLDC/RLDC Common Information Model (CIM) in NLDC Classical data presentation plus alarm processing, exception lists, animation, geographical displays Multilayering, Trending SoE and replay

9. Jurisdiction of Load Despatch Centers NLDC: Apex body to ensure integrated operation of National Power System RLDC: Apex body to ensure integrated operation of power system in the concerned region 5 SLDC: Apex body to ensure integrated operation of power system in a state 31

10. Jurisdiction of RLDCs/SLDCs • Control Area • Scheduling Responsibilities • RLDCs • State as a whole • ISGS /UMPPs, • Pvt. Generating Stations > 1000 MW and having > 50% share of state outside home state #CERC Order 58/2008, Suo Moto • SLDCs • State Utilities ( SGS / Discoms) • Intra-State Entities

11. National Load Despatch Center (NLDC) MAIN NLDC, DELHI ERLDC WRLDC NERLDC NRLDC SRLDC BACKUP NLDC, KOLKATA F.O. Cable on each 2E1 Link Copper Cable –(Backup) VSAT– (Backup) each 64Kb/s

12. Functions of Load Dispatch Centers • Optimum scheduling and dispatch of electricity • Monitoring of operations and grid security • Keeping accounts of the quantity of electricity transmitted through the regional grid • Supervision and control over the transmission system • Real time operations for grid control • Dispatch of electricity through secure and economic operation of in accordance with the Grid Standards and the Grid Code

13. Foundation Stones Two firm footings INDIAN ELECTRICITY GRID CODE (IEGC) AVAILABILITY BASED TARIFF (ABT) System Operation IEGC ABT Electricity Act 2003

14. Regional Grid Operation: Philosophy Operated as loose power pools States have full operational autonomy State power system treated as notional (flexible) control area Very tight control of actual interchange by state utilities & Inter State Generating Stations not mandated Deviations from net drawal schedules appropriately priced

15. GRID MANAGEMENT FUNCTIONS Ex-ante functions Scheduling Real-time functions Supervision & control of system parameters Facilitating Open Access transactions Post-facto functions Settlement system operation Interaction with stakeholders

16. Balancing market guiding vector

17. UI mechanism • Maximizes social welfare • Transparent, neutral & rigging proof • Diffuses market power • Ultimate open access • Facilitates reforms in the sector • Encourages trade and bilateral exchanges • Facilitates exchanges (arbitrage) between regional power pools

18. The End Result …. • Frequency is • collectively controlled • democratically stabilized • Wholesale market is workably competitive • allocative efficiency • productive efficiency • Economic signal available for • optimum utilization of resource • investments in generation capacity • Settlement is • streamlined • dispute-free

19. INDIAN ELECTRICITY MARKET

20. Evolution of Power Market in India Ancillaries, PX 2008 Open Access 2004 Settlement System 2002-03 Grid Code Feb.’2000

21. Market Design Four Pillars of Market Design ELECTRICITY MARKET SCHEDULING & DISPATCH CONGESTION MANAGEMENT ANCILLARY SERVICES IMBALANCES “Making Competition Work in Electricity”, Sally Hunt

22. Total Transfer Capability Voltage Limit Thermal Limit Power Flow Stability Limit Total Transfer Capability Time Total Transfer Capability is the minimum of the Thermal Limit, Voltage Limit and the Stability Limit 22-Sep-14 22

23. Transmission Capacity vs Transfer Capability

25. Total & Available Transfer Capability Transfer Reliability Margin (TRM) Capacity Benefit Margin (CBM) TTC Long Term Open Access (LTOA) ATC Short Term Open Access (STOA) ATC = TTC – TRM – CBM “Reliability is the performance level of the elements of the bulk electric systems that results in electricity being delivered to the customers within accepted standards and in amount desired. It is expressed in terms of the frequency, duration and magnitude of adverse effects on electric supply. Reliability comprises of Adequacy and Security…Adequacy is reliability within the range of events which can be controlled by operators whereas Security is reliability under conditions beyond the control of operators.” Dr. Mohammad Shahideopour

26. CERC Open Access Regulations, 2008 • Effective 01.04.2008 • Permits usage of spare transmission capacity through a transparent process • Offers choice and freedom to buy & sell power • Transactions categorized as Bilateral and Collective (through Power Exchange) • Transmission Charges moved from “Contract Path” to “Point of Connection” for Collective Transaction • Thrust on Empowerment of SLDCs

27. Bilateral - Contingency Bilateral - Advance Bilateral - FCFS Collective Through PX Day - Ahead Time Line

28. Trade under Short-Term Open Access * 2008-09 data includes Bilateral + Collective transactions.

29. ENERGY APPROVED(MU) - (Nodal RLDC-NRLDC) 2007-08 2008-09 2005-06 2006-07

30. ENERGY APPROVED(MU) - (Nodal RLDC-SRLDC) 2008-09 2007-08 2006-07 2005-06

31. Growing Confidence in Open Access Market - Increasing Market Players

32. Power Exchange in India • Salient Features • Multiple exchanges – Competition amongst Exchanges • Indian Energy Exchange (IEX) • Power Exchange of India (PXI) • Third Power Exchange in the offing: • Voluntary participation • Double sided bidding • Uniform pricing • Day-ahead exchange • Hourly bids • Congestion management by market splitting

33. Daily Energy Traded on PX

34. Increasing Participation on PX

35. Open Access: Key Success Factors • Developed in consultation with all stake holders • Control area demarcation & boundary metering • Robust transmission system • Assessment of Transfer Capability • Balancing mechanism • Methodology for transmission charge sharing • Treatment of transmission losses • Streamlined scheduling and settlement mechanism • Transparency and non-discriminatory implementation • Compliance • Dispute redressal mechanism • Congestion management

36. Transmission Congestion • Characteristics of a growing power system • Sign of optimum investment • If managed and documented • Gives signals for future investments • If unmanaged • A pain • Threat to grid security • May lead to social and economic loss • Situation gets acute in Northern Region due to indiscriminate overdrawal

37. SR ER+NER WR NR SKEWED LOAD GENERATION BALANCE Skewed Load-Generation Balance • Scenarios: • 4S • 3S + 1D (Congestion) • 2S + 2D • 1S + 3D • 4D

38. FLOWGATES

39. Congestion Management: Bid Area

40. PECULIARITIES & CHALLENGES Skewed resource distribution Long-haulage of power Resource Inadequacy Weather extremes Diversity High growth, high uncertainties Unbundling and reforms Evolving market mechanisms Changing business environment Loose Power Pool Decentralized Operation Floating Frequency Unscheduled Interchange Voluntary ancillary services Weekly settlement 21 day cycle 15-minute settlement period Dynamically varying resource sharing matrix Excessive reliance on UI Freedom and choice without enforcement of obligations Unclear jurisdiction

41. DAILY OPERATIONAL CHALLENGES FLOATING FREQUENCY: 49 - 50.5 Hz VOLTAGE VARIATIONS: 380- 430 kV BI-DIRECTIONAL LINE FLOWS HIGH RAMP RATE

42. Concerns Reliability of physical system Adequacy, Security, Dependability Rapid growth Harmonization Jurisdiction Visualization and situational awareness Dynamic system Deployment of technology Automation, Information exchange Capacity building Inclusive, sustainable, broad based Human Resource

43. VISUALIZATION CHALLENGES BEFORE US Expanding requirements Technological up gradation Database & display updating Maintaining data quality Operator familiarization

44. SITUATIONAL AWARENESS

45. Expectations Focus on reliability of the physical system Designing markets that complement reliability Appreciation of System Operation as an important function Allocation of resources Automation Capacity building Grid security comes before Economics No economic theory, no legislation, no regulation can repeal the Laws of Physics “Power markets are the only markets that can suffer a catastrophic instability that develops in less than a second...The extent and speed of the required coordination are unparalleled.” ….Steven Stoft

46. Building up the Immune System • Protection • New technologies • Co-ordination • Power System Early Warning Systems • PMU • WAMS • Defense mechanisms • System Protection Schemes

47. Thank You sksoonee@gmail.com sksoonee@powergridindia.com