1. 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

2. Indian Power Grid – its Evolution
Phenomenal expansion since Independence (1947)
Generation : 1349 MW ,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)

3. 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

4. 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

5. Growth of installed capacity for electricity in India

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

8. Sector wise consumption of electricity in India

9. Hydro Thermal mix in India

11. Growth of Cumulative capacity of Inter-regional links

12. NORTHERN REGION

13. 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).

14. 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 %, BBMB—9.9%, State—50.3%

15. 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.

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

21. COMMERCIAL MECHANISM

22. 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)

23. 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.

24. 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

25. POWER SYSTEM OPERATION
MODERNISATION OF
POWER SYSTEM OPERATION
ULDC SCHEME

26. 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

27. 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

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

29. 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

30. 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

31. 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)

32. 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

33. 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.

37. Thank You