Smog affecting power transmission in Punjab, Malwa region worst hit
Malwa is the worst hit as power lines in the region tripped seven times in the past five days due to smog.punjab Updated: Nov 13, 2017 09:02 IST
Smog is not only giving health problems to residents in the state, it has also become a cause of concern for the Punjab State Power Corporation Limited (PSPCL) as it is frequently disrupting power transmission too.
Malwa is the worst hit in this regard as power lines in the region tripped seven times in the past five days due to smog. The tripping of lines resulted into shutdown of the 1800 MW Talwandi Sabo power plant twice, forcing the corporation to impose power cuts causing inconvenience to consumers.
When dust particles, clubbed with fog and moisture, increase in size and get deposited on insulating discs of high-voltage transmission lines, they increase electrical conductivity and thus power line trips.
The Talwandi Sabo plant tripped on Sunday as well and it was not reported functional till filing of this report.
After having supplied fairly good power during the peak demand of 11,000 MW to 12,000 MW in summer/paddy season, the PSPCL is finding it hard to supply uninterrupted power now when the demand has dived down to almost one third (4,000 MW). This is due to the repeated trippings of high-voltage transmission lines, particularly 400 KV lines emanating from private thermal plants at Talwandi Sabo, during the past one week.
Meanwhile, the state-run thermal plants at Ropar, Lehra and Bathinda are shut down due to less demand. The 50% of the present power demand, over 2,000 MW, is met by the supply from the Talwandi plant (1,400 MW to 1,600 MW) and the Rajpura plant (660 MW).
There are a total of six lines of 400 KV emanating from the Talwandi plant — two each to Muktsar and Dhuri, one each to Nakodar and Moga.
While the 400 KV Talwandi-Muktsar line got tripped at 4.40 am on November 6, the other five lines tripped one after another on November 7 from midnight onwards.
This resulted in tripping of all the three units of Talwandi plant, which was supplying about 1,100 MW power at that time. The plant took a lot of time to restart generation of power, creating a blackout situation in several areas of Malwa on November 8.
PSPCL RESORTS TO POWER CUTS
The PSPCL was forced to impose power cuts during this period on rural and agricultural feeders, including vegetable feeders. After the situation normalised, the Lehra thermal unit was shut down on November 9. The power supply to one of the Talwandi-Dhuri lines was restored finally on Saturday (November 11).
Alarm buttons were pressed again when five out of six 400 KV lines from the Talwandi plant again tripped one after another on Sunday (November 12) morning. All the three units of the Talwandi plant tripped and stopped generation at 7.15 am on Sunday.
The PSPCL resorted to power cuts again on Sunday, causing inconvenience to public. The generation from the Talwandi plant has not been restored so far.
Punjab State Transmission Corporation Limited (PSTCL) director (technical) Shashi Prabha cited smog as the main reason behind tripping of power lines. “After paddy harvesting, usually there is a rain, which cleanses our insulating discs. This time there was no rain and the prevailing smog led to tripping.”
Besides, the PSPCL has shifted the entire load to the Talwandi Sabo line. “I have asked PSPCL to light up one unit each of their plants for uniform supply generation and distribution,” she added.
MAINTENANCE PROBLEM, SAY POWER ENGINEERS
However, power engineers differ with her.
“The main reason behind these trippings is the deposit of dust and carbon particles on insulating discs of high-voltage transmission lines and these getting flashed during fog,” said a power engineer.
He added, “The northern region power committee has repeatedly asked the PSTCL to replace the conventional insulating discs with modern age polymer discs, but the PSTCL response was not up to mark. The usual drill to clean/wash insulating discs periodically with water to remove the dust/carbon particles is also not being followed by PSTCL.”
He said the private plant of Talwandi Sabo Power Limited (TSPL) is taking unjustified long time to restart its units because it is not financially hit by the line trippings. During the trippings caused by transmission line faults, it continues to get fixed charges even if there is no generation, he added.