Tuesday December 07, 2021

Countrywide blackout: Improper maintenance of TLs, load safeguard system failure responsible

The crisis worsened because of absence of the spinning reserves, top officials having technical knowhow of the power sector say

January 11, 2021
Motorists drive through a residential area during a power blackout in Pakistan´s port city of Karachi early on January 10, 2021. / AFP

ISLAMABAD: Improper maintenance of transmission lines (TLs) and failure of safeguard system against load rendered the Guddu Power House dysfunctional, causing the countrywide blackout.

The crisis worsened because of absence of the spinning reserves, top officials having technical knowhow of the power sector confided to The News.

However, Federal Minister for Energy Omar Ayub Khan said he was on toes to find out the root-cause of the massive breakdown and once it was known, it would be made public.

However, he said the transmission lines and insulators were being looked after properly, and the safeguard system against the load did not collapse. In fact, it was Guddu plant, which went out of the system owing to which frequency instantly dropped to zero from 50, but it is yet to be known in which circuit the fault appeared, he added.

“This had the cascading effect on every power plant in the country, which, in turn, became dysfunctional, and resultantly the whole power generation system collapsed.”

Omar Ayub insisted that he would go into details to find out the main cause that triggered the countrywide electric blackout.

To a question, he said so far 80 per cent of the country had been energized and till late Sunday night, electricity would be restored in remaining parts of the country.

The coal-power plants, the minister said, would be made functional till late Sunday night as they take 18 hours to get a position required for generating electricity. However, the nuclear power plants would become functional by Monday, as under the protocol, nuclear power plants take one-and-a-half days or two days to become functional. Once all the plants come on stream, hydrogenation would be reduced.

However, officials having technical knowledge about the power sector said the country was rich in electricity generation capacity by over 36000-MW but the government of the day failed to maintain the spinning reserves, which play an important role in preventing the power breakdown when any powerhouse becomes dysfunctional for any reason.

In the developed economies, when a power plant goes out of the system, the spinning reserves come into action and play the role in maintaining the system without any jerk.

“Spinning reserve is the most important contingency reserve because the generators that provide it power are already running (spinning), synchronised to the grid and can, therefore, respond immediately, either manually or automatically, to changes in system frequency.

“The government should have arranged the spinning reserves knowing the fact the country is in surplus in electricity generation.”

For many years, they claimed, the protection system installed at the power plants against the load had not been upgraded and the incumbent government did not pay attention to the very issue.

The official said Guddu power house was placed in mid country where, during the winter season, a dense fog was always found, and this was the area from where the fault originated causing the power breakdown.

In 2013, 2015 and 2017, the electrical blackouts gripped the country mainly because of negligence in maintenance of transmission lines and washing of insulators.

Officials claim that this time the National Transmission & Despatch Company (NTDC) had not properly maintained the transmission system and washed the insulators, resulting in tripping of the high transmission line.

The second reason is that the safeguard system against the load failed. The transmission was carrying a load of 300MW for Balochistan. And because of failure of the protection system against the load, Guddu power plant got tripped.

"Had the protection system against the load worked properly, the Guddu power plant would not have become dysfunctional," they claimed.

They said if the polluted transmission lines and their insulators had been maintained and washed properly, the transmission line would have not tripped. In the absence of maintenance, chances become bright for tripping of transmission lines due to short-circuiting, they added.