Evaluation of Lightning Outage Rate Considering Line Surge Arrester Failure

Line surge arresters are installed mainly in the three phases of one side of double-circuit transmission lines to prevent double-circuit faults. In addition, there are some cases where arresters are installed in five phases or the six phases of those. Recently, the proportion of the arrester installation is rising remarkably. It is important to evaluate the rate of arrester failures due to the energy stress caused by lightning, because there is possibility that lightning strokes to transmission lines with large peaks and/or long duration of currents cause arrester failures. In this paper, we examine the lightning stroke current causing arrester failures and the frequency of the arrester failures in 77kV double-circuit transmission lines. Moreover, it is cleared that the optimal phase to omit an arrester is one lower phase for five phases installation of arresters.