Ice accretions on high-voltage conductors and insulators and related phenomena

This paper proposes to survey a good part of the research work accomplished to date on the atmospheric icing of conductors and insulators in the prese nce of high voltage, with emphasis laid on the studies carried out at the U niversity of Quebec in Chicoutimi. The review covers laboratory testing and mathematical modelling. The role of several electrical parameters, such as electric field strength and polarity, corona discharge, water droplet charge and ionic wind velocit y, on the structure and amount of ice accretion on high-voltage conductors, is discussed. Concerning the icing of insulators, the initiation of electrical discharge on the ice surface, the formation of local arcs along the air gaps and thei r development to a flashover are along the insulators are discussed. Basic experiments on the role of several major parameters relating to ice accreti on, insulator characteristics and voltage type and polarity, on the maximum withstand voltage of short insulators, are also discussed. Finally, severa l measures for improving the withstand voltage of insulators are briefly re called.