Agitating electricity workers in Seemandhra have been switching off substations in tandem with key generation units,helping insulate the southern grid from potential damage.
As large swathes of coastal Andhra and Rayalaseema reel under a self-inflicted power shortfall of nearly 4,000 MW,the Bangalore regional office of the national grid operator,Power System Operation Corp Ltd (POSOCO),is on high alert. Control room staff are working shifts to keep a round-the-clock watch for an impact of the Andhra situation on the operating parameters of the southern grid.
The saving grace for them,though,is that the striking workers,who have crippled power generation by shutting three major stations,have simultaneously shut substations the links between generating stations and consumers,through which power flows at several voltage levels as well.
This means that while generation is down by about a third of Andhra Pradeshs total installed capacity of 12,973 MW,shut substations have ensured that the strain on the grid is much less than what it could have been. Also,striking workers have so far not disrupted power flows from NTPCs central generating stations to neighbouring states such as Tamil Nadu.
The shutting down of 12 key substations has cushioned the damage from the three generation projects shutting down. Over the past three days,electricity workers have been following a pattern switching off these substations early in the morning and switching them back on at about 6 in the evening. The crash in generation is automatically counterbalanced to a large extent by the crash in the load, a senior Delhi-based grid operations official said.
The southern grid,of which Andhra Pradesh is part,is linked to the rest of the country through HVDC (high voltage direct current) lines that have constraints on wheeling capacity,thereby limiting the free flow of power from and to the southern region.