Life management of high voltage bushings

Black Point Power Station (BPPS) is Hong Kong's first natural gas-fired power plant, consisting of eight 312.5MW single-shaft combined-cycle units. The first six units C1-C6 were progressively commissioned in 1996-1998 while the last two units C7-C8 came into operation in 2005 and 2006 respectively. Each generator is independently connected to a 420MVA generator transformer converting the 23kV generator output to the nominal 435kV transmission voltage. This paper outlines the maintenance strategies of HV line bushings where CLP Generation Business Group has put in tremendous effort in monitoring the bushing condition, as well as adopting risk mitigating measures in securing the system reliability. These include routine inspection and testing such as power factor test, UV scanning and oil sampling for DGA. Effective life cycle maintenance is developed based on international standard and OEM recommendation.