Assessing Partial Discharge on Composite Insulators Under Desert Pollution Conditions

Transmission lines located in the Sinai desert are subjected to desert climate, one of whose features, especially in the spring, is sand storms. Line insulators are thus exposed to sand contamination, which may produce streamer discharges in the air surrounding insulator surface. Such discharges may lead to flashover. This paper examines the electric field and potential distributions on sand-polluted composite insulators. These insulators are nominated to replace ceramic insulators on transmission lines in Sinai. A case study is presented using an ABBdesigned composite insulator, where the insulator surface electric field is investigated under dry sand-pollution conditions and with different sand grain sizes. The latter were provided by a previous study of the Sinai desert. Finite element techniques are used to simulate the insulator and seek electric field distribution on the polluted insulator model and around it. This study helps in partially assessing –and thus justifyingthe use of these insulators in those critical areas. Keywords— Composite insulators, Desert pollution, Partial discharge, ANSYS software, Sinai.