Operation Experience of 500 kV and Below Transmission Line and Suggestions of Polluted Insulation Disposition for 1000 kV Transmission Line

Combined with the operation experience of 500 kV and the below transmission line, this paper summarized that the external insulation disposition of transmission line is the prime cause of pollution flashover for 500 kV and the below transmission line. The suggestions about polluted insulation disposition, specific distance of creepage, number of piece in insulator string and length of string for 500 kV and 1000 kV AC transmission line are put forward.