System Operations through National Regional Load Dispatch

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

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

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

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

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

Growth of IR Exchanges

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 – 24 x 7 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

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 • So. E and replay

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 31 SLDC: Apex body to ensure integrated operation of power system in a state

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

National Load Despatch Center (NLDC) MAIN NLDC, DELHI NRLDC SRLDC ERLDC WRLDC NERLDC BACKUP NLDC, KOLKATA F. O. Cable on each 2 E 1 Link Copper Cable –(Backup) VSAT– (Backup) each

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

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

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

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

Balancing market guiding vector

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

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

INDIAN ELECTRICITY MARKET ENABLERS Legislation Indian Electricity Act 2003 National Electricity Policy 12 -Feb-2005, Para 5. 7. 1(d) Regulation IEGC-Feb 2000 ABT Order-Jan 2000 Open Access-May-2004 Power Exchange-Aug-2007 Execution CTU/STU, RLDC/SLDC Grid & Market Operation Control Centres & SEMs ABT settlement: in stages 2002 -03 STRUCTURE Balancing Mechanism Frequency linked Unscheduled Interchange Intra-day STOA Day-ahead Power Exchange Multiple Power Exchanges Short-term Bilateral Day-ahead First-come-first served Three-month ahead Long-term Bilateral Shared resources (ISGS) Own resources

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

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

Total Transfer Capability Thermal Limit Power Flow Voltage Limit Stability Limit Total Transfer Capability Time Total Transfer Capability is the minimum of the Thermal Limit, Voltage Limit and the Stability Limit 18 -Mar-18 22

Transmission Capacity vs Transfer Capability Transmission Capacity Transfer Capability 1 Is a physical property in isolation Is a collective behaviour of a system 2 Depends on design only Depends on design, topology, system conditions, accuracy of assumptions 3 Deterministic Probabilistic 4 Constant under a set of conditions Always varying 5 Time independent Time dependent 6 Non-directional Directional 7 Determined directly by design Estimated indirectly using simulation models 8 Declared by designer/ manufacturer Declared by the Grid Operator 9 Understood by all Frequently misunderstood 10 Considered unambiguous & sacrosanct Subject to close scrutiny by all stakeholders

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

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

Time Line Collective Through PX Bilateral FCFS Bilateral Advance Day Ahead Bilateral Contingency

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

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

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

Growing Confidence in Open Access Market - Increasing Market Players

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

Daily Energy Traded on PX

Increasing Participation on PX

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

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

SKEWED LOAD GENERATION BALANCE Skewed Load-Generation Balance NR Scenarios: 1. 4 S WR ER+ NER 2. 3 S + 1 D (Congestion) 3. 2 S + 2 D 4. 1 S + 3 D SR 5. 4 D

FLOWGATES

Congestion Management: Bid Area Region States N 1 North JK, HP, CHD, PUN, HAR N 2 North RAJ, DEL, UP, UTT W 1 West MP, CHTG W 2 West MAH, GUJ, GOA, DD, DNH S 1 South AP, KAR, GOA S 2 South TN, KER, PONDY E 1 East WB, SIK, BIH, JHAR E 2 East ORISSA A 1 North-East Tripura, Manipur Mizoram, Meghalya A 2 North-East Assam, Ar. Pradesh, Nagaland

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

DAILY OPERATIONAL CHALLENGES FLOATING FREQUENCY: 49 - 50. 5 Hz BI-DIRECTIONAL LINE FLOWS VOLTAGE VARIATIONS: 380 - 430 k. V HIGH RAMP RATE

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

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

SITUATIONAL AWARENESS

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

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

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