Abstract
The primary aim of surge arresters in power distribution lines is to protect lines and apparatus from overvoltages induced by nearby lightning strokes. For further improvement in the performance of the power distribution system, protection methods for distribution lines against direct lightning strokes must be devised. One effective measure against direct lightning strokes is to increase the number of surge arresters. However, if the lighting current is considerably large, some surge arresters will absorb a large amount of energy in excess of their withstand capability and break down, thereby leading to a line fault.
This paper reports on the energy duty of surge arresters due to direct lightning hits to overhead ground wire. Also, the failure rate of surge arresters is estimated in accordance with the calculated energy duty.
