• Sudden drop in frequency caused the crisis • Inquiry launched to determine reasons for the tripping
LAHORE: Almost the entire country plunged into darkness late on Saturday night after a major breakdown in the national grid shut down a number of hydel and thermal power stations one by one in stunning fashion.
The breakdown was so severe that the country’s entire power transmission, dispatch and distribution system of over 22,000MW tripped, leaving cities and towns in Punjab, Sindh, Balochistan and Khyber Pakhtunkhwa in darkness.
“A countrywide blackout has been caused by a sudden plunge in frequency in the power transmission system,” Power Minister Omar Ayub Khan said on Twitter.
Efforts were being made to restart the Tarbela power plant after which electricity supply to the entire country would be restored in phases, the minister said.
Mr Khan said efforts were also under way to determine the reasons behind the crisis, and asked people across the country to remain calm.
According to the National Transmission and Despatch Company (NTDC), the breakdown took place when frequency in the system suddenly dropped to zero from 50.
An NTDC official said the fault caused the entire 220kV and 500kV transmission and grid system of the company to trip. The 66kV to 132kV distribution of the power distribution companies, including K-Electric, Lesco, Qesco, Gepco, Mepco and IESCO, was badly affected as a result.
“If the transmission frequency drops to zero from 50, it means the entire system goes idle. Restoration of the frequency to 50 takes time,” he explained.
He said an inquiry had been ordered by senior functionaries to determine the reasons behind the sudden drop in frequency.
A spokesman for the power division said special teams had reached Tarbela and efforts were continuing to restart the power station there. According to a preliminary report, he said, the fault had originated at Guddu power plant at 11:41pm on Saturday.
“The entire city of Lahore appears to be without power after the breakdown hit the country at about 11:50pm,” said an official of the Lahore Electric Supply Company (Lesco). “We tried to know the reason, but no one from the NTDC responded to our calls.”
After hectic efforts to restore electricity supply across the country, the Warsak power station came back online at about 1:10am (Sunday).
By the time this report was filed, the power division was claiming that three units of the Tarbela power station were back online. “Warsak power station’s units also resumed operations.
“The NTDC engineering staff is currently working to synchronise the system gradually to attain the transmission frequency of 50,” a spokesman said.
Meanwhile, many consumers in Lahore complained that Lesco personnel concerned were not attending their calls.
“No one even bothered to pick my repeated calls at the airline subdivision, Johar Town,” a consumer said while talking to Dawn.
Power supply to 30 of the of 33 districts of Balochistan got severed from three circuits of the NTDC, official sources said.
A spokesman for the Quetta Electric Supply Company (Qesco), Afzal Baloch, said three of the province’s districts — Turbat, Gwadar and Panjgur — were continuing to get electricity from Iran.
He said that power supply to the other 30 districts from the Quetta-Sibi, Khuzdar-Shahdadkot and Dera Ghazi Khan-Loralai circuits had been snapped.
Saleem Shahid in Quetta also contributed to this report
Published in Dawn, January 10th, 2021