India began utilizing grid management on a regional basis during the 1960s. Individual State grids were interconnected to form 5 regional grids covering mainland India. These grids were the Northern, Eastern, Western, North Eastern and Southern grids, established to enable the transmission of surplus electricity between States in each region of the country.
During the 1990s, the Indian government began planning for a national grid. Regional grids were initially interconnected by asynchronous HVDC back-to-back links facilitating a limited exchange of regulated power. The links were subsequently upgraded to high-capacity synchronous links.
The first interconnection of regional grids was established in October 1991 when the North Eastern and Eastern grids were interconnected. The Western grid was interconnected with the aforementioned grids in March 2003. The Northern grid was subsequently also interconnected in August 2006, forming a Central grid synchronously connected and operating at one frequency.
The sole remaining regional grid, the Southern Grid, was synchronously interconnected to the Central Grid on 31 December 2013 with the commissioning of the 765 kV Raichur-Solapur transmission line, thereby establishing the National Grid.
The National Grid is the high-voltage electricity transmission network in India, connecting power stations and major substations, ensuring that electricity generated anywhere in the country can be used to satisfy demand elsewhere. The National Grid is owned, and maintained by the state-owned Power Grid Corporation of India (www.powergrid.in) and operated by the state-owned Power System Operation Corporation. It is one of the largest operating synchronous grids in the world with 371.054 GW of installed power generation capacity as of 30 June 2020.
The union territories of Andaman and Nicobar Islands and Lakshadweep are not connected to the National Grid. Both territories being archipelagos are located far away from the mainland. Due to the geography and topography of these islands, including separation by sea over great distances, there is no single power grid for all the electrified islands in the archipelago.
The power generation and distribution systems of these territories are served by standalone power, with each electrified island in the archipelago having its generation and distribution system. Power stations cater independently to the power requirements of an area. The Electricity Department of Andaman and Nicobar (EDA&N) and the Lakshadweep Electricity Department (LED) are responsible for the generation, transmission and distribution systems in these territories.
India’s grid is connected as a wide area synchronous grid nominally running at 50 Hz. The permissible range of the frequency band is 49.5-50.5 Hz, effective 17 September 2012. The Federal Government regulates grid frequency by requiring States to pay more when they draw power at low frequencies. There are also synchronous interconnections to Bhutan, and asynchronous links with Bangladesh, Myanmar, and Nepal. An undersea interconnection to Sri Lanka (India–Sri Lanka HVDC Interconnection) has also been proposed. A similarly proposed interconnection between Myanmar and Thailand would facilitate the creation of a power pool and enable trading among all BIMSTEC nations.
Presently, India imports electricity from Bhutan with synchronous transmission links while exporting power to Nepal, Bangladesh and Myanmar with asynchronous transmission links between the National Grid and the electricity grids of these countries.
India has committed to having installed a renewable energy capacity of 450 GW by 2030 and has been at the forefront of renewable energy generation, transmission and distribution. The generated renewable energy is also currently being slowly integrated into the national power grid system cutting down on carbon emissions.
This Post was submitted by Climate Scorecard India Country Manager Pooran Chandra Pandey
Key contact in National Grid Management System:
Mr. K. Sreekant, Chairman & Managing Director,
Power Grid Corporation of India, Saudamini, Plot no. 2, Sector. 29, Near IFFCO Chowk, Gurgaon (Haryana)-122001, India, Telephone: +91-124-2822000, 2823000