Research and Development on Flashover of Ice-covered Insulators

The electrical characteristics of ice-covered insulators is one of the key issues in developing anti-flashover measures for the insulators. Although there are many experiments and theoretical investigations of this issue worldwide, from which a lot of valuable results has been obtained, icing flashover accidents are still far from being prevented. Therefore, it is necessary to summarize these research results of flashovers on ice-covered insulator, so as to provide references for and guide further efforts on development of anti-flashover measures. On the basis of the rich experimental investigations on icing flashover and anti-icing measures of insulators carried both at home and abroad in last eighty years, we systematically summarized and analyzed various factors and mechanisms that affect icing flashover from aspects including physical characteristics of icing surface, test methods, characteristics and mathematical models of icing flashovers, etc., and consequently presented the relations of the icing flashover voltage of insulators to icing type, salt density of contamination, conductivity of icing water, icing amount, pressure, type of applied voltage, etc. We also proposed some key topics, which covered icing flashover's mechanism and characteristics and its mathematical prediction models, as well as some suggestions and ideas, for future researches of icing flashovers on insulator.