UTILITY OF MODERN LOAD DISPATCH COMMUNICATION SYSTEMS GRID OPERATION AND UTILITY OF MODERN LOAD DISPATCH COMMUNICATION SYSTEMS ALOK ROY General Manager Northern Regional Load Dispatch Center

Indian Power Grid – its Evolution Phenomenal expansion since Independence (1947) Generation : 1349 MW 105,800 MW (in 1947) (in 2003) Grid : Local grid – at the time of Independence. State Grids – emerged in 1960s. Regional Grids – in 1970s. Five Regional Grids – Northern, Western, Southern, Eastern & North-eastern National Grid – All Five Regions Interconnected (2002)

IEGC operates on states periphery State Govt. SERC IPPs SGC CPPs STU SLDC Distn Cos. Consumers Central Govt. CERC CGC Imports CTU RLDC REB CEA IEGC operates on states periphery Complementary to Availability Tariff Endeavour to maintain frequency in the 49.0 – 50.5 Hz range Free Governor mode of operation Charge for reactive energy - Voltage related

Indian Power System Has Peculiarities Hence Solutions Are Tailor Made Departures From Conventional Practices: - Frequency would be allowed to float - Actual Interchanges would be allowed to deviate from the scheduled interchanges - Frequency linked generation dispatch - Frequency linked pricing of deviations from scheduled interchange leading to spot and balancing market solutions - Trading could be in the form of a deviation from scheduled interchange rather than on pre-agreed/scheduled basis

Growth of installed capacity for electricity in India

Fuel wise break-up of installed capacity in power sector Total installed capacity is 105,800 MW

Sector wise consumption of electricity in India

Hydro Thermal mix in India

Growth of Cumulative capacity of Inter-regional links

NORTHERN REGION

Northern Regional Power System Salient Features Northern Regional Power System Largest in geographical area amongst the five regions of India covering 30.7% of the area and approx 29.9% of the country’s population . Largest number of participating constituents (9 states, 5 Central generating companies, one Central Transmission Utility and Bhakra Beas Management Board).

Northern Regional Power System Salient Features Northern Regional Power System Effective generation capacity 28794 MW Regional Peak Met 23015 MW Average Energy Consumption 425 MU / day Central --39.4%, BBMB—9.9%, State—50.3%

Northern Regional Power System Salient Features Northern Regional Power System Transmission system + 500 kV HVDC 1630 Ckt. Kms. 15033 Ckt. Kms. 400 kV 220 kV 28353 Ckt. Kms. TOTAL 45016 Ckt. Kms.

Northern Regional Power System Salient Features Northern Regional Power System Largest Generating Stations Thermal (coal fired) SSTPS(NTPC) 2000 MW Hydro Bhakra Complex (BBMB) 1493 MW Nuclear RAPS Complex (NPC) 740 MW Thermal (gas fired) Dadri Gas (NTPC) 829.78 MW

COMMERCIAL MECHANISM

AVAILABILITY BASED TARIFF CAPACITY CHARGE ENERGY CHARGE ADJUSTMENT FOR DEVIATIONS (U I CHARGE) (A) = a function of the Ex-Bus MW availability of Power Plant for the day declared before the day starts x SEB’s % share (B) = MWh for the day as per Ex-Bus drawal schedule for the SEB finalised before the day starts x Energy charge rate (C) = Σ (Actual energy interchange in a 15 minute time block – scheduled energy interchange for the time block) x UI rate for the time block TOTAL PAYMENT FOR THE DAY = (A) + (B) ± (C)

ADVANTAGES : (A) AND (B) DO NOT DEPEND ON ACTUAL PLANT AVAILABILITY AND GENERATION / DRAWAL. ALL DEVIATIONS TAKEN CARE OF BY (C). NO COMPLICATION REGARDING DEEMED GENERATION. NO NEED FOR UNANNOUNCED TESTS. PERPETUAL INCENTIVE FOR MAXIMISING GENERATION AND REDUCING DRAWAL DURING DEFECIT, BUT NO INCENTIVE TO OVER GENERATE DURING SURPLUS.

UNSCHEDULED INTERCHANGES (UI) I.E. DEVIATIONS FROM SCHEDULES ENCOURAGED IF GOOD FOR THE GRID, DISCOURAGED IF BAD FOR THE GRID, BUT ALLOWED BECAUSE IT ENABLES MEETING MORE DEMAND AND ENHANCES MERRIT-ORDER. GOOD UI HELPS IN IMPROVING FREQUENCY AND ENABLES ONE CONSTITUENT TO HELP THE OTHER (FOR MEETING MORE CONSUMER DEMAND I.E REDUCING LOAD SHEDDING) UI PROVIDES THE MECHANISM FOR ON-LINE DISPLACEMENT OF COSTLIER GENERATION BY CHEAPER GENERATION : ULTIMATE OPTIMISATION

POWER SYSTEM OPERATION MODERNISATION OF POWER SYSTEM OPERATION ULDC SCHEME

UNIFIED LOAD DESPATCH & COMMUNICATION (ULDC) SCHEMES POWERGRID is implementing ULDC schemes in all the five regions with state of the art SCADA Energy Management System and Dedicated Communication System

ULD & C PROJECT: OBJECTIVES To have Greater and deeper visibility of the power system under control Better communication and co-ordination between control centers Effective management of grid parameters viz. frequency, voltage etc. and better grid security through various SCADA/EMS features resulting in better Operations scheduling Operations monitoring and control Power system analysis A real time environment for dispatcher training

HIERARCHICAL SETUP NLDC 5 Nos. ERLDC WRLDC NRLDC SRLDC NERLDC 32 Nos. SLDC 51 Nos. SUB LDC 1160 Nos. RTU

UNIFIED LOAD DESPATCH & COMMUNICATION SCHEME (NORTHERN REGION) HPSEB 1 SLDC 2 Sub-LDC 16 RTUs J&K SEB 1 SLDC 1 Sub-LDC 16 RTUs Jammu & Kashmir Bemina BBMB 1 SLDC 4 Sub-LDC 21 RTUs F PSEB 1 SLDC 2 Sub-LDC 40 RTUs Gladni H Hamirpur Jallandhar (B) Himachal Pradesh Ganguwal (B) Jallandhar (P) Jutogh F F F Kunihar F H F Chandigarh,BBMB Punjab Laltonkalan H H Rishikesh Uttaranchal 1 SLDC 27 RTUs F H ana F Rishikesh Patiala Panipat (BBMB) Narwana F H F HVPNL 1 SLDC 2 Sub-LDC 42 RTUs Hary Panipat(HSEB) F Dadri (B) J F F DVB Moradabad F H F F F Delhi Dadri (H) Ratangarh F Uttar Pradesh DVB 1 SLDC 4 Sub-LDC 31 RTUs Rajasthan H Panki H Lucknow F Heerapura F Sultanpur F RVPNL 1 SLDC 3 Sub-LDC 79 RTUs F Kota F Bhilwara F Varanasi Madhya Pradesh Gujarat UPPCL 1 SLDC 4 Sub-LDC 55 RTUs RLDC NEW DELHI 36 RTUs CPCC KANPUR 6 RTUs H SLDC Sub - LDC F

Unique Features of Northern Region ULDC Scheme Three Level Hierarchical Control centres More than ten electrical utilities involved Highly Complex system First Time attempted in the world as a Single Project Dedicated communication Infrastructure Live Line Fibre Optic Cable Stringing More than 30 control centres and 400 RTUs Advance Despatcher training Simulator

SUPERVISORY CONTROL & DATA ACQUISITION (SCADA) FUNCTIONS RTU DATA ACQUISITION SUPERVISORY CONTROL DATA EXCHANGE DATA PROCESSING (Alarms, SOE,Generalized calculations) DISTURBANCE DATA COLLECTION HISTORICAL INFORMATION STORAGE & RETRIEVAL (ISR)

EMS FEATURES OPERATION SCHEDULING Load forecasting Inflow forecasting Unit commitment Hydro scheduling Hydro Thermal Coordination Interchange scheduling Current operating plan Outage scheduling LOAD GENERATION BALANCE Operation monitoring AGC Economic despatch Reserve monitoring Loadshed /Restoration Production costing POWER SYSTEM ANALYSIS Network Topology State estimation Contingency analysis Optimal power flow Transmission loss sensitivity factors Post disturbance analysis

Dispatcher Training Simulator Primary use: Training of Dispatchers for routine and emergency scenario in a controlled and safe off-line manner. Network split, blackouts Large voltage or frequency excursions Engineering tool for operations planning (generation plans, network switching, etc..) and for understanding of power system behavior.

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