Study on Surge Arrester Impulse Stress in a 500kV AC Switch Yard Under Multiple Lightning Strikes

Surge arresters are the primary equipment for overvoltage protection, and the effective coordination among the protective characteristics of surge arresters, system overvoltage characteristics, and equipment insulation characteristics is fundamental to the safe and stable operation of the system. In this paper, a model of the AC side lines of a converter station was established to study and analyze the magnitude of electrical stress and the waveform of impulse current experienced by surge arresters when multiple lightning strokes occur on the AC side conductors of the converter station. The applicability of the current surge arrester selection under conditions of multiple lightning invasion waves was verified, and a systematic analysis was conducted to compare the electrical stress on surge arresters under multiple lightning strikes with that under a single lightning strike.