September 14, 2012

According to media reports, the government said the southern power transmission grid will be connected with the national grid by January, 2014. This will happen once the entire southern grid is also connected and will have one frequency across India.

Power Grid Corporation (PGCIL) is constructing a 800 kV transmission link between Raichur in Karnataka and Sholapur in Maharashtra to connect the southern grid with rest of the national grid.

The national grid is presently demarcated into five regional grids i.e. Northern, Southern, Eastern, Western and North-eastern. Except the southern grid, all other grids are operating in synchronism since August 2006 and have a single frequency.

All the grids are being run by Power Grid Corporation, which operates more than 95,000 circuit km of transmission lines.

The southern grid is presently linked with the national grid through asynchronous high voltage direct current (HVDC) transmission line and has a different frequency.

The integration of southern grid will help states like Tamil Nadu, Andhra Pradesh, Kerala, Karnataka and Puducherry in getting their due share of power from the national grid.

Power frequency reflects the load generation balance in the grid at a particular period and is one of the most important parameters for assessment of the security of power system and the quality of power supply. The grids in the country have a permissible frequency band between 49.5 Hz to 50.2 Hz.