Black start exercises experience in Western Region, India

Black start in power system basically means restoring a generating unit with its auxiliaries supplied by DG set or battery and extending power supply to loads after dead bus charging and energizing a transmission line to seek loads. This is the first step in system restoration post a partial or total black out in any part of an electrical power grid. In view of growing complexity in power system with addition of new generation, transmission and distribution network the need for a well-tested plan for system restoration has gained currency across system operators round the globe. Going forward, with gradual development of a mature power market in India the black start facility of existing and upcoming generating stations can be commoditized and possibly traded as an ancillary service to the power system users for which each black start capable generator would be required to get its black start capability validated and certified on a regular basis. Black start mock drills are planned grid restoration exercises carried out by the system operators on a live power system to test the capability of existing black start sources like hydro / gas turbine generators and validate the existing grid restoration strategies. These exercises do also play a vital role in boosting confidence of the system operators to deal with a real black out scenario. This paper describes four black start exercises, various lessons learnt and experience gained during black start exercises carried out at three black start capable hydro stations and one black start capable gas turbine based generating station in Western Regional Power grid of India.