Nov 28, 2010 (LBO) – Sri Lanka was hit by cascading outage Sunday afternoon after a key transmission line tripped out of the national grid, but officials at the state-run power utility said electricity was restored before nightfall. Power failed in most part of the island after a transmission lines from the Kotmale and Victoria hydro generation complexes running to Biyagama near the island’s capital tripped out of the system.
Except for two parts of the grid in Rantembe and Badulla, power to the rest of the country was lost.
The reason for the trip was not yet known, officials said.
The national grid has been susceptible to cascading outages in recent years.
Cascading failures are triggered by the failure of one part of the grid, which may create an imbalance between demand and supply of power.
Parts of the grid including generators will rapidly trip out of the system and shut down to protect themselves, requiring several hours to get the system back up.
They can be triggered by specific equipment failures or weather.