A new application concept of transmission line arresters to 500-kV lines

More than half of the electrical faults on transmission lines are caused by lightning in Japan. In order to improve their lightning performance, gapped type transmission line arresters have been installed in many service lines since 1986. It is general that the arresters are installed on three phases of one circuit of double-circuit transmission lines to prevent interruptions of supply due to lightning flashover. The authors developed a new lightning surge analysis method, which is able to simulate the actual faults, by reviewing the existing parameters. Using this analysis method, they have studied new application concept of the arrester on 500 kV transmission lines with high-speed reclosing systems. As a result, it is found that the application of two arresters per one circuit of double-circuit line is able to prevent interruptions of supply.