| To adapt the need of power load for the quick development of economy, the development of power system is turning for the higher voltage and larger capacity direction. Using multiple -circuit transmission line is the developing tide for 500kV main configuration to reduce line holding ground. So it is important significance and applied value for 500kV multiple-circuit transmission line on same tower lightning protection performance designing.The paper presents studies of the lightning performance of 500kV double-circuit. A numerical method has been developed to predict Back Flashover Rate based on Bergeron traveling wave method. It can truly reflect the spreading course of lightning current on the tower. This paper calculates and analyses the lightning protection performance of back striking for AC 500kV double-circuit transmission line by program in detail. Furthermore, considering the randomness of working voltage phase when lightning strokes the top tower and supposing the equal probability of lightning appearing arbitrary phase in a cycle of AC, this paper adopts the statistical method to calculate the rate of back stroking on double circuit line. Compared with the result of that of Qinghua University and EMTP (Electro-Magnetic Transient Program), the validity of the calculation program is approved. The paper presents the measures to reduce the rate of back stroking and their harm by the calculation program for the lightning protection performance of back striking for AC 500kV four-circuit transmission line on one tower.With the calculation program, the effect of differential insulation and the phase arrangement of conduct and grounding resistance is discussed as measure to reduce double-circuit trip out rate in details. Finally, a proper lightning resisting measure is presented. These results will propose reference for the same type of transmission line.Research on the Lightning Protection Performance of Back Striking for 500kV Multiple -circuit Transmission Line...
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