Analysis on the Technology and Economy of Lightning Protection Measures for Treble-circuit Transmission Lines

摘要

The treble-circuit transmission lines are widely used to increasing energy transportation efficiency and saving land. Because of symmetrical electric structure, the treble-circuit transmission lines suffer from lightning trip-out for more than one circuit in a lightning strike. In this paper, an analysis model for lightning performances of treble-circuit transmission line was established. A typical treble-circuit transmission line with abundant operating data was taken as analytic target. The technical economies of two lightning protection devices and four layout schemes were discussed. By setting insulator parallel gaps and surge arresters in one circuit of a treble-circuit transmission line to break the electric balance, the average lightning trip-out rate for more than one circuit flashing can be reduced by 50%. According to the analysis result of lightning performance, setting lightning protection devices selectively can improve its lightning performance effectively with lesser cost, which has a good technology and economy.