Inclined and Tortuous Lightning Channel Impact on Lightning Performance Assessment of Distribution Lines with a Shield Wire

Abstract:
Recent studies have shown the impact of a lightning electromagnetic pulse (LEMP) on overvoltages generated by a direct lightning strike to medium-voltage distribution lines. In this study, we extended an electromagnetic transient analysis method, which can incorporate the LEMP impact, so that inclined and tortuous lightning channels can be simulated. The proposed method was validated by three-dimensional finite-difference time-domain analysis for solving Maxwell’s equa-tions. Then, the method was applied to the statistical evaluation of the impact of inclined and tortuous lightning channels on the lightning performance assessment of distribution lines with a shield wire. The analysis clarified that channel tor-tuosity has little impact on the lightning performance assessment, but it changes the flashover locations and phases in a large number of events. Thus, channel tortuosity can have an important role in analyzing the observed lightning outages.