One Nation One Grid One Frequency

Context

Power Grid Corporation Limited celebrated the anniversary of the achievement of “One Nation One Grid”, as a part of Azadi Ka Amrit Mahotsav.

Evolution of National Grid

• Grid management in the country, on a regional basis started in the sixties. At the beginning, state grids were interconnected to form a regional grid and India was demarcated into 5 regions namely -
• Northern Grid
• Eastern Grid
• Western Grid
• North Eastern Grid
• Southern region
• With time each grid was connected to the other, to allow greater availability and transfer of power. 
• The North-Eastern and Eastern Grid were connected in October 1991.
• Western Grid and North Eastern Grid were interconnected in March 2003.
• In 2006, North and East grids were interconnected.
• Thus, 4 regional grids Northern, Eastern, Western and North Eastern grids were interconnected to form a central grid operating at one frequency.
• On 31st December 2013, Southern Region was connected to Central Grid in Synchronous mode with the commissioning of 765kV Raichur-Solapur Transmission line thereby achieving 'ONE NATION'-'ONE GRID'-'ONE FREQUENCY'.

• The Srinagar Leh Transmission System was connected to the National Grid, and was dedicated to the nation in 2019.

Present total transmission capacity

• Presently, the country has a total inter-regional transmission capacity of about 1,12,250 MW which is expected to be enhanced to about 1,18,740 MW by 2022.