Friday, January 18, 2013

POWER GRID IN INDIA


                                                                  
 ‘Transmission’ and ‘Grid Management’ are essential functions for smooth evacuation of    power from generating stations to the  consumers. Transmission function primarily  consists of construction and maintenance of  the transmission infrastructure while the job of the grid operator is to give operating  instructions to the engineers in the field and ensure moment-to-moment power balance in  the interconnected power system. Grid  management involves taking care of the over  all reliability, security, economy and  efficiency of the power system.







Fig-1: Five Regional grids in India
Grid Management in India is carried out on a regional basis. The country is geographically divided in five regions namely, Northern, Eastern, Western North Eastern and Southern. All the states and union territories in India fall in either of these regions. The first four out these five regional grids are operating in a synchronous mode, which implies that the power across these regions can flow seamlessly as per the relative load generation balance. The Southern Region is  interconnected with the  rest of India grid  through asynchronous links. This implies that  quantum and direction of power flow between  Southern Grid and rest of India grid can be
manually controlled.  Load Despatch Centres    Each of the five regions has a Regional Load  Despatch Centre (RLDC), which is the apex  body, as per the Electricity Act 2003 (EA 2003), to ensure integrated operation of the power system in the concerned region. The  RLDCs for North, East, West, South and  Northeast regions are located at Delhi, Kolkatta, Mumbai, Bangalore and Shillong  respectively. 





Fig-2: Load Despatch Centres

The RLDCs coordinate amongst themselves  both offline as well as online for maintaining  the security and stability of the integrated panIndia grid. In line with the federal structure of  governance in the country, every state has a  State Load Despatch Centre (SLDC), which is  the apex body to ensure integrated operation of the power system in the state




Fig-3: Regional Load Despatch Centres The RLDCs in India are presently owned,
managed and operated by the Central Transmission Utility (CTU), POWERGRID
while the SLDCs in the state are owned operated and managed by the respective State
Transmission Utility (STU) or the State Electricity Board (SEB) as the case may be.
The EA 2003 has a provision for a National Load Despatch Centre (NLDC) for optimum scheduling and despatch of electricity across various regions and also coordinating cross  border energy exchanges in real time. Ministry  of Power has notified the functions of NLDC  that is under construction. Presently,
POWERGRID is operating a National Power  System Desk (NPSD) in New Delhi for
information exchange and facilitating interregional transactions. The cross border
exchanges are coordinated by the RLDC of the region wherein the international
interconnection is situated.  Role of Load Despatch Centres   As per the Electricity Act 2003, the Regional  Load Despatch Centre monitor grid  operations, exercise supervision and control  over the inter-state transmission system, are  responsible for optimum scheduling and  despatch of electricity within the region, in  accordance with the contracts entered into with the licensees or the generating companies
operating in the region and keep accounts of  quantity of electricity transmitted through the  regional grid. RLDC is responsible for  carrying out real time  operations of grid  control and despatch of electricity within the  region through secure and economic operation  of the regional grid in accordance with the  Grid Standards and Grid Code. The functions  of SLDC elaborated in EA 2003 are similar to  that of the RLDC except the area of jurisdiction, which in case of SLDC is the  state.