Two separate committees have been formed to investigate a blackout across 10 districts of the Khulna and Barisal regions.
The Power Division and the Power Grid Company of Bangladesh each formed a committee on Sunday, confirmed Mohammad Shafiullah, information and public relations officer of the Ministry of Power, Energy and Mineral Resources.
According to sources from the ministry, preliminary analysis of the collected information indicates that a transient short-circuit occurred between the blue phase of Circuit-1 and the red phase of Circuit-2, approximately 65km from the Aminbazar substation and 25km from the Gopalganj substation.
As a result, the protective relays installed for system protection at both ends of the circuits operated automatically, causing the associated power plants to trip, as per the sources.
Shafiullah said: "Once the committees submit their reports, the detailed causes behind the tripping and other associated issues of the power outage will become clear."
Sources from the ministry said that the power situation in the grid network was normal on Saturday. On that day at 5pm, the total generation was 14,520 megawatts and the system frequency was 50.4 hertz.
Under these conditions, following a fault that occurred at 5:45pm on the 400kV (Kilovolt) Aminbazar-Gopalganj double-circuit line, temporary power outages occurred in 10 districts related to the Jessore, Benapole, and Noapara substations in the Khulna and Barisal regions, sources said.
However, as the 230kV Ishurdi-Bheramara-Jhenaidah link remained operational, the substations at Bheramara, Kushtia, Magura, Narail, and Chuadanga, connected at the 230kV and 132kV levels, stayed active, they added.
Using this 230kV link, the NLDC (National Load Dispatch Centre) of the Power Grid Company and other relevant offices promptly and efficiently managed to restore power at the Jessore, Benapole, and Noapara substations.
As a result, power supply in these areas began to return to normal, they said.
On the other hand, due to the fault on the 400kV Aminbazar-Gopalganj double-circuit line, several power plants tripped, causing a loss of approximately 2,277 megawatts of power, as per ministry sources.
These plants include the 1,320MW BCPCL (Payra) plant, the 1,320MW RNPL plant, the 307MW Barisal Electric, the 1,320MW Rampal plant, the new 225MW Bhola power plant, the 225MW Bhola power station, and the 500MW HVDC Block-2.
According to the sources, at 6:19pm, Circuit-1 of the 400kV Aminbazar-Gopalganj line was restored, followed by Circuit-2 at 6:25pm, which made the 400kV Aminbazar-Gopalganj-Amtali link operational.
In this situation, with the synchronization of power, Unit-1 of the 1,320MW BCPCL (Payra) power plant was synchronized at 7:01pm, followed by Unit-2 at 7:08pm. By around 7:30pm, power supply across these regions began returning to normal.
As other power plants were gradually synchronized to the grid network, the power situation fully normalized by 8pm, they said.
