Faults analysis of lightning stroke-caused flashover in 220 kV double-circuit transmission lines on the same tower

Abstract

In this paper, four-phase simultaneous lightning stroke-caused faults have been analysed, which occurred in double-circuit transmission lines on the same tower. According to the fault patrol circumstance, lightning information data, fault recording imformation, ATP-EMTP transient simulation analysis, it can be determined that the four-phase flashover faults were caused by backflashover. The specific process was: lightning stroke top or ground line of 75# tower. The lightning current was shunted by the ground wire and the tower, and was injected into the earth through the grounding device, cause high electric potential to rise on the top of 75# tower, and backflashover overvoltage formed across the insulators of phase B and phase C, leading to insulators flashover and simultaneous trip-out.