Switching transient studies of 345kV combined transmission systems

This paper describes switching overvoltage of 345[kV] combined transmission system. Generally, switching overvoltage may cause the breakdown of insulation or joints of the underground power cable section. Therefore, in this paper, the various switching overvoltages are analysed according to the change of fault resistance, the amplitude of trapped charge and underground cable rate on 345[kV] combined transmission systems. The effects of pre-insertion resistance and surge arrester are also considered. The overvoltage calculations are only performed by statistical approach of EMTP/ATP.