Reasonable lightning protection design is essential to ensure the operation safety and reduce the cost for 500kV quadruple-circuits transmission lines. Therefore, a more accuracy analysis on lightning surge characteristics of the line is necessary. This paper provides experimental and analytical studies on lightning surge response of 500kV Quadruple-circuit transmission line.  The accuracy of the FDTD(Finite-Difference Time Domain) method was verified based on a comparison with experimental results. Subsequently, it analyzed lightning surge characteristics of 500kV quadruple-circuit transmission line under near-real facility condition. Furthermore, it studied the influences of the rise time of injecting current, the velocity of return-stroke current and the angles of transmission line on the lightning surge characteristics. These effects had been ignored in previous lightning surge analysis by EMTP. As a result, insulator strings voltage at the same tower arm was almost equal, although the span of 500kV quadruple-circuit tower arm was very large. Furthermore, it was found that the rise time of injecting current and the velocity of return-stroke current  greatly impact the lightning surge response. The inclination angle of transmission lines in different terrains also influenced the lightning surge response. So these factors should be carefully considered when higher accuracy lightning protection design is necessary.

The error of ground inclination data,elevation data,Electrical geometric model,shielding failure,lightning risk level