A Multiphase Flashover Analysis of EHV Transmission Lines Taking into Account Electromagnetic Field Generated by Return Stroke Current

Abstract

The electromagnetic radiation field generated by a return stroke current has not been taken into account in a conventrt lightning surge analysis for a direct lightning hit to a transmission line tower. The electromagnetic field, however, greatly affects arcing-horn voltage. Then, a calculation method to deal with the radiation field in the EMTP as a lightning-induced-voltage sot was developed by the authors.
The double-circuit outage on EHV transmission lines in Hokuriku district caused by a winter lightning is one of the n important and serious problems in electric power systems. The winter lightning has been observed to make clear the flasht mechanism of the outage. As a result, it is cleared that the winter lightning is quite different from summer one. Tlius, it is expe, that the peculiarity of a winter lightning discharge causes a multiphase flashover. This paper investigates the effect of the radia field on the multiphase flashover, and compares the actual lightning performance of the multiphase flashover on EHV transmis, lines with calculated results.