The thunderstorm of Thursday has lent a massive jolt to power transmission infrastructure across Punjab. Three towers of 400KV Ludhiana-Malerkotla supply line collapsed besides tripping of a large number of 220KV lines.
In all, at least 12 main transmission lines tripped across the region due to high-velocity wind, triggering sharp reduction in the power demand, ironically threatening the Northern Grid that ended up housing much more voltage than usual. Of the 12 lines of 400KV, six tripped in Punjab.
As per estimates, 1,200 electricity poles and 350 transformers were damaged in Ludhiana, Patiala, Sangrur and SAS Nagar districts.
The grid frequency reached 50.71 Hz at 5.05 PM on Thursday as the demand dipped from 36,965 MW to 30,874 MW. Usually, the frequency is in the range of 49.7 to 50.5 HZ. Emergency lines were opened to control the high voltage. The grid had collapsed twice in the summer of 2012 due to overdrawal. Punjab, Haryana, Delhi, Himachal Pradesh, Jammu and Kashmir, Rajasthan, Uttar Pradesh and Uttarakhand draw power from the grid. Of these states, only Uttarakhand did not underdraw on Thursday night.
"Due to bad weather in the northern region, the electricity demand dropped by about 6,095 MW at 5 pm on Thursday. It led to high-frequency and high-voltage conditions in the grid," read the communiqué of Northern Regional Load Despatch Centre (NRLDC).
Meanwhile, the Punjab State Power Corporation Limited (PSPCL) asked employees to work overtime to re-erect electricity poles and lines. PSPCL chairman KD Chaudhary said, "All important lines are back in operation, and the remaining will be on by midnight (on Friday)."