Performance of 400 kV line insulators under pollution

Abstract

Investigation of the cause of repeated tripping of a 400 kV, AC transmission line has been reported in this paper. Failure of insulation strings in the months of December and January in a small length of the 400 km long line were caused due to peculiar fumes coming out from salt kilns. The laboratory investigations performed under simulated conditions of line pollution revealed a drastic fall in the flashover voltages. Excessively high creepage currents were measured under fog and polluted conditions. Performance of these insulators with RTV coating was also investigated