A Greasing Method for Improving The Performances of Polluted Insulators.(Dept.E)

Abstract

The present experimental work reports an investigation of the effect of artificial pollution on the performance of suspension ingulators. It was found experimentally that the greasing of suspension insulators by silicone grease improve their performancos oven undor heavy pollution conditions. A silicono grease layer of comparatively small thickness reduces the effect of dirt accumulation and increase the flashover voltage. The leakage current of greased insulators is very lower than that of ungreased insulators. It was found also that the flashover mschanism of polluted insulators under both d.c. and a.c. voltagos depends mainly on the formation of dry-bands, formed by the leakage current. As the applied voltage is increase, these bands extend in width causing partial sparkings across them and leading finally to a totally flashover over the insulator.