ECONOMYNEXT – Sri Lanka’s state-run Ceylon Electricity Board is restoring power gradually after a cascading failure amid unusually high hydro generation, led to a national-wide blackout officials said.
Three and a hours after the failure parts of the capital was still without power though electricity had been restored to many areas.
A CEB official said a transmission line from the Mahaweli hydro complex running from Kotmale to Biyagama in the capital district which failed on Friday for the second time in a week, is suspected to have triggered the failure.
Sri Lanka has been experiencing heavy rains leading to record inflows to hydro power stations and the CEB has been trying to make maximum use of the resource.
The Kotmale-Biyagama line is a weak link in the grid and the utility is building an additional transmission line via Polipitiya to reduce its dependence, but the project has still not finished, an official said.
When part of the grid loses power, generators also trip of the grid as part of automatic protection mechanism, which can in turn de-stabilize other parts of the grid leading to a cascading failure. It takes several hours to restore power.
Coal plants involved in emergency shut down which blow their steam escaping diaphrams can take days to restore.
Due to the vulnerability of the transmission line CEB had allowed Mahaweli reservoirs to spill, during the usually high rainfall seen in 2021.
Sri Lanka last experienced total cascading failure in August 2020. (Colombo/Dec03/2021)