Application of line surge arresters to double-circuit transmission lines

Installation of line surge arresters is quite effective in improving lightning performance of transmission lines. So, cost-effective installation schemes depending on the condition of lines have been sought. In recent years, due to the reduction of the cost of line surge arresters for lower voltage transmission lines, installation rate at some lower voltage transmission lines in Japan has much improved, and failures of line surge arresters have been reported along with it At such transmission lines, failures of surge arresters need to be taken into account in evaluating the lightning performance. The lightning performance of double-circuit transmission lines equipped with three or more arresters per tower taking account of their failures is discussed.