Lightning-induced voltages on overhead lines over irregular terrains

摘要

This paper analyzes lightning-induced voltages on distribution lines located on irregular terrains since it is common, in some places in the world, that real distribution systems are placed on those terrains. Simplified topographies were used in this analysis to approximate to those found on real distribution systems. The lightning-induced voltages were calculated with a full-wave analysis approach based on the 3D Finite-Difference Time-Domain (FDTD) method. It was found that lightning-induced voltages on overhead lines above irregular topographies, in the majority of cases, are greater than those found for flat terrain. The enhancement factor can reach values up to 5.2 times. In a few cases, factors below unity were found. These results may give a new insight on the design of overhead distribution lines for improving lightning performance on real distribution networks.