'Overloading could be reason for grid collapse'

Grid overloading could be one of the probable reasons for the northern power grid collapse last night, according to energy experts of state power utility APTransco.

“The normal frequency at which electricity is transmitted through the northern grid ranges from 49.5 Hz to 50.2 Hz (cycles/second). At the time of the collapse at around 2.35 am on July 30, the grid frequency was 50.46 Hz, a few notches above the normal frequency,” the state energy co-ordination cell said in a press release on Monday.

Andhra Pradesh, a part of the southern power grid, which includes the states of Tamil Nadu, Karnataka, Kerala and Puducherry, remained fully insulated from the grid disturbances in the north, it said. Effective fault analyses, round-the-clock monitoring of the grid, automatic disturbance-control mechanism and island-mode grid mechanism helped keep the state grid supply in tact, the release said.