The Unit-III of the Mangdechhu Hydroelectric Power Plant in Trongsa is down since September 21 after a flashover inside its stator and winding jumper has led to the shutdown of the turbine. It is expected to take a month or two to restore. However, project officials said there is no loss in the power generation as the water volume is declining and the water in the dam is only enough for the three turbines.
“The flashover is a kind of sparks that happens may be due to vibrations or insulation failures which has created carbonization in machines and we had to shut down,” said Chencho Tshering, the Joint Managing Director for MHPA.
The carbonization is the phenomenon of dirtying of stator windings and other components inside the turbine when there are sparks or flash thereby causing an electric short-circuit.
“And we have to clean up the whole system and replace the jumper and rotor poles as everything becomes carbonized. So these happenings are not fundamentally and electrically very catastrophic as it was safe for us to not have a fire but just a flashover,” he said.
The Joint Managing Director added that similar flashover followed by carbonization occurred in one of the turbines earlier and it got restored within a month time. And during the operation and maintenance (O&M) period of any new Hydropower Plant, such problems arise.
“But we do not want to rush in the maintenance work this time as the monsoon is now over and the lean season is beginning. So on a rotational basis, we want to update the problems. And moreover, we have to carry out the annual maintenance for all the machines,” he added.
Currently, the turbine is dismantled and the restoration works are in full swing. A committee from headquarter has also visited the site, assessed and decided about how to go about.
Meanwhile so far, the four turbines of the project generated around Nu 16bn after a year from its inception.
Passang
