Simulation analysis of lightning performance of 1000kV UHV-AC transmission lines

The lightning performance of 1000kV UHV-AC transmission lines is an issue that must be considered in line design, especially the accurate calculation of the lightning shielding failure trip-out rate (SFTR) of 1000kV UHV-AC lines, which is essential for the scientific assessment of the lightning protection design schemes for 1000kV lines. In order to accurately evaluate and calculate the lightning performance of 1000kV UHV-AC transmission lines under different design schemes and conditions, this paper combines the discharge test data of the State Grid Corporation's UHV-AC test base for negative short-wave front operating impulse voltage under long gap (up to 10m) conditions, and proposes EGM striking distance calculation formulas and correction method for the geodesic striking distance factors applicable to 1000kV EHV large-size lines. And the simulation study of the back flashover and shielding failure performance under the typical design of 1000kV UHV-AC lines was carried out using the modified EGM and electromagnetic transient program (EMTP), respectively. The various sensitive influencing factors of the lightning trip-out rate (LTR) of 1000kV UHV-AC lines are analyzed, and the comprehensive lightning characteristics and engineering design suggestions of 1000kV UHV-AC transmission lines are proposed.