Obstacles faced in testing commissioning of 231 MW Chamera Hydroelectric Project Stage-III located in Himalayan State, Himachal Pradesh India- A Case Study.

摘要

There were many challenges faced during testing & commissioning of 3x77MW Chamera Hydroelectric Project located in the State of Himachal Pradesh, India. This is an under ground Power Station having 15.99 KM long Head Race Tunnel (HRT) with a gross head of 230m and net head of 200m. All the 3 units of this project were commissioned in a record time of 25 days. Many challenges were encountered during first filling of HRT & commissioning of the project such as leakage in Adits of HRT, leakage from adit to pressure shaft (located inside under ground power house) and leakage of water around the surge shaft area leading to displacement of soil/slides along the hill slope which is inhabited by a small village. Besides the difficulties in completion of civil components, a big incident occurred during the testing & commissioning of the power station in June 2012. There was an accidental application of manual brakes to Unit-1 of the Project which was running on full speed (333 rpm) for heat run test. Actually Brake was to be applied manually to Unit No-3 which was given a stop command during testing process by commissioning team. A young trainee engineer was asked by his Manager during the testing of Unit-3 to go to the generator floor from machine hall and apply brakes to Unit-3 manually. Unit-I was also running on full speed for heat run test. The Engineer Confused Unit-3 for Unit-1 (as the breaking system of all the units is located on generator floor) and applied brakes to Unit-1 instead of Unit-3. There was a big thunder sound and the whole Power House cavern was full of smoke due to carbon dust. Visibility was approximately 20%. Unfortunately the HVAC system was not commissioned which could have taken out the smoke through exhaust. There was heavy suffocation inside the underground power house. It took 10 hrs for the smoke to settle. The whole generator barrel was full of carbon dust.