Power Grid Corporation of India, a central transmission utility, was able to restore the Northern Grid operations by 4 pm on Monday. R N Nayak, chairman and managing director, explains to Sanjay Jog what could have gone wrong and how the restoration was done. Edited excerpts:
What led to today’s grid failure?
Before the occurrence, there was overdrawal of power by various constituents of the northern region grid. However, this alone could not be the reason for the failure. A grid failure due to a technical snag cannot be ruled out. The leading causes will be known only after a proper analysis.
PowerGrid will also conduct a thorough inquiry, by an internal committee comprising officials from the operations division. The committee will come out with its findings in two months.
How did PowerGrid carry out restoration?
We brought power from the eastern and western region grids and gave start-up power to the generators from the northern region progressively, from 8 am onwards. By 10.30 am, nearly 20,000 Mw of load was connected, of which 4,000 Mw was exported from the eastern and western region grids and 8,200 Mw of hydro power plants. We ensured supply at all our sub-stations by noon. However, constituents and most generating plants, particularly thermal units, could bring back full generation and load only by 4 pm. Nearly 30,000 Mw of load was connected to the northern grid by 5 pm.
What was PowerGrid’s priority during restoration of grid operations?
We made all efforts for restoration of emergency services and the public transport system by about 8 am. The power supply to Delhi Metro (the commuter rail network), railways and airport was restored by that time.
How was the restoration achieved?
Purely due to proper coordination among a large number of people spread over the region. We established coordination with state generating companies, state transmission companies and central power generating stations. Senior officials of PowerGrid had reached the Northern Regional Load Despatch Centre by 3 am.
What is the key to maintaining grid security?
My sincere appeal to all concerned is to adhere strictly to grid discipline. Any instruction from the regional load despatch centre should be complied with, in true letter and spirit. In no case should constituent states exceed the safe loading limit.