Suppression of lightning-induced overvoltages by distribution line surge arresters

The primary aim of surge arresters in power distribution lines is to protect lines and equipment from the voltage induced by nearby lightning strokes. To further improve power systems, methods to protect distribution lines against direct lightning strokes are still needed. An effective measure against direct lightning strokes is to increase the number of arresters. However, if the surge current is too large, some surge arresters absorb energy in excess of their capability and may break; this leads to a line fault. To evaluate the protective effect of the surge arresters against direct lightning strokes to overhead ground wire, the authors measured both the voltage across the surge arresters and the energy absorbed by them using a full-scale model line and a 12 MV impulse generator. The results were compared with simulation results by EMTP. There have been no previous studies making a comparison of this kind.