The interconnection line used for transmission of 450 megawatts at Bheramara in Kushtia district, tripped at 11:30 am, a source at Power Development Board (PDB) said.
The sudden vacuum caused disruption of power generation at all power plants across the country, the Daily Star reported.
Some power plants resumed generation at around 1:00 pm.
State Power Minister Nasrul Hamid Bipu said power generation is expected to return to near normal by evening.
Power supply has resumed on emergency basis at Hazrat Shahjalal International Airport in Dhaka and major hospitals.
Dhaka Medical College and Hospital, the country's largest public hospital, also used a standby generator.
