Pakistan power outage caused by failure of safeguards

ISLAMABAD, Jan 11:
One of the worst power outages faced by Pakistan last week was caused due to poor maintenance and subsequent failure of the protection system in the national grid, the Dawn reported on Monday. The newspaper reported that senior officers held detailed discussions after many cities and towns across Pakistan plunged into darkness Saturday night following a major technical fault in the country’s power generation and distribution system.
The officials admitted that the blackout had exposed the mismanagement on the part of the government in running the entire power sector of the country on an ad hoc basis, it said.
The chief executive officers of all the three key companies concerned – the Central Power Generation Company-Guddu, the National Transmission and Dispatch Company (NTDC) and the National Power Control Centre (NPCC) – have been working on ad hoc or acting charge basis for years. The Central Power Generation Company (CPGC) runs the Guddu Power Station where the initial technical fault was reported to have taken place, leading to Karachi, Rawalpindi, Lahore, Islamabad, Multan and other places facing the blackout. The NTDC operates the country’s national grid whose protection system should have reacted to the Guddu station’s tripping and isolated the fault. Its system, meant to stop the transmission frequency from dropping, apparently did not work resulting in the cascading closure of all the power plants across the country in a matter of seconds.
The NPCC monitors the flow of electricity from power plants to various distribution companies (Discos). It has to manage supply systems for proper load and frequency balancing.
Even the Discos are working without regular chief executive officers for more than two and a half years, the newspaper said.
The NTDC is without a regular chief executive officer since July 2017 while NPCC has not seen a full-time CEO for more than a decade. The NPCC chief, working on a temporary basis, was hired last year from the private sector.
The country’s Prime Minister Imran Khan has reportedly expressed displeasure over non-filling of the posts in power companies.
That a human error triggered the massive outage was indirectly confirmed by Engineer Hammad Amer Hashmi on Sunday when he suspended seven employees of the Guddu station working under plant manager-III and blamed them for negligence.
At a news conference, Energy Minister Omar Ayub Khan said the breakdown occurred due to a technical fault at the Guddu station, which resulted in frequency declining from 50 to zero within seconds.
Officials said the initial fault appeared to have occurred at the Guddu station’s switchyard, but the protection system of the transmission network did not respond to the fault.
The transmission system should have rejected the load from Guddu station through an automatic protection mechanism, but apparently this did not happen because of poor or insufficient maintenance and non-washing of transmission lines.
The Guddu-Sibi transmission line has been a familiar trouble spot because of extreme fog and other environmental issues and has seen tripping in the past as well.
The protection system had been separating southern and northern parts of the country’s grid in the past.
“This is clearly a failure of the protection system,” said a retired senior officer.
He said the transmission lines used to be washed every year, sometimes repeatedly, depending on the fog in winters. He also called into question the past government claims that the protection system had been improved, particularly after the 2015 breakdown.
Had the system been improved it would have gone into an island mode. Saturday’s power outage was the third such incident since 2015, which meant the protection system was either not upgraded or the upgrade was insufficient, said the retired officer.
Meanwhile, the officials said the transmission network had been synchronised for now, but the entire transmission and distribution network would take some time, maybe until Monday, to completely stabilise as repeated load swings were being witnessed in many parts of the country. (PTI)

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