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

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

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

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

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

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

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 SLDC: Apex body to ensure integrated operation of power system in a state 31 5

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) ERLDCWRLDCNERLDC BACKUP NLDC, KOLKATA MAIN NLDC, DELHI SRLDCNRLDC F.O. Cable on each 2E1 Link Copper Cable –(Backup) VSAT– (Backup) each 64Kb/s

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

Electricity Act 2003 Foundation Stones IEGCABT System Operation 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-Jan2000 Open Access-May-2004 Power Exchange-Aug-2007 Execution CTU/STU, RLDC/SLDC Grid & Market Operation Control Centres & SEMs ABT settlement: in stages 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

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

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

17-May-1522 Total Transfer Capability 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

Transmission Capacity vs Transfer Capability Transmission CapacityTransfer Capability 1Is a physical property in isolationIs a collective behaviour of a system 2Depends on design onlyDepends on design, topology, system conditions, accuracy of assumptions 3DeterministicProbabilistic 4Constant under a set of conditionsAlways varying 5Time independentTime dependent 6Non-directionalDirectional 7Determined directly by designEstimated indirectly using simulation models 8Declared by designer/ manufacturerDeclared by the Grid Operator 9Understood by allFrequently misunderstood 10Considered unambiguous & sacrosanctSubject to close scrutiny by all stakeholders

Total & Available Transfer Capability ATC = TTC – TRM – CBM Transfer Reliability Margin (TRM) Capacity Benefit Margin (CBM) Long Term Open Access (LTOA) Short Term Open Access (STOA) TTC ATC “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 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 Bilateral - Advance Bilateral - FCFS Collective Through PX Day - Ahead Bilateral - Contingency

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

ENERGY APPROVED(MU) - (Nodal RLDC- NRLDC )

ENERGY APPROVED(MU) - (Nodal RLDC- SRLDC )

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 SR ER+ NER WR NR Scenarios: 1.4S 2.3S + 1D (Congestion) 3.2S + 2D 4.1S + 3D 5.4D SKEWED LOAD GENERATION BALANCE

FLOWGATES

Congestion Management: Bid Area Are a RegionStates N1NorthJK, HP, CHD, PUN, HAR N2NorthRAJ,DEL, UP, UTT W1WestMP, CHTG W2WestMAH,GUJ, GOA, DD,DNH S1SouthAP, KAR, GOA S2SouthTN, KER, PONDY E1EastWB, SIK, BIH, JHAR E2EastORISSA A1North- East Tripura, Manipur Mizoram, Meghalya A2North- East Assam, Ar. Pradesh, Nagaland

PECULIARITIES & CHALLENGES Skewed resource distribution Long-haulage of power Resource Inadequacy Weather extremes Diversity Dynamically varying resource sharing matrix Excessive reliance on UI Freedom and choice without enforcement of obligations Unclear jurisdiction 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

DAILY OPERATIONAL CHALLENGES FLOATING FREQUENCY: HzVOLTAGE VARIATIONS: kV HIGH RAMP RATEBI-DIRECTIONAL LINE FLOWS

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