Lightning Protection Method of Power Distribution Lines Located in Mountainous Areas Facing the Sea of Japan

Abstract

Non member Tsuyoshi Koide (Tohoku Electric Power Co.) Member Kazuo Nakada (Hokuriku Electric Power Co.) Lightning strokes with a large amount of energy sometimes occur on the Sea of Japan coast in winter. Winter lightning often damages overhead power distribution lines, in particular, those supplying power to high structures located in mountainous areas. We have investigated the characteristics of lightning outages on such distribution lines in order to establish effective countermeasures against damage from winter lightning. The ratio of surge arrester damages with respect to all damaged installations on such power distribution lines is largest at approximately 50%. We have examined the effectiveness of installing two pairs of surge arresters in parallel on a single pole as a method for preventing distribution surge arrester damages experimentally. In the case of two pairs of 2.5 kA rated arresters with the same discharge voltage, simultaneous discharge can be obtained easily when the peak value of the injected current is large or the rise time of the injected current is short.