Study on Flashover Characteristic and Critical Flashover Current of icing and polluted 110kV Composite Insulators

Abstract

In this paper, the artificial pollution test and artificial icing test of the FXBW-110/100 composite insulators are carried out in the artificial climate chamber. The test results show that the flashover voltage($U_f$) of composite insulator decreases with the increase of salt density and the surface of the insulator, the flashover voltage and salt deposit density(SDD) meet the negative exponential relationship, the pollution characteristic index(±) which indicated the effects of SDD on $U_{f}$ were 0.355, 0.338 and 0.352, respectively, when the composite insulators were under the conditions of uncovered ice, ice covered 5mm and ice covered 10mm. Under the same pollution conditions, the flashover voltage of ice covered insulators is lower than that of the insulators without icing. The flashover voltage of ice covered insulator decreased with the increasing of the thickness of icing layer on the insulator. The critical flashover current of icing and polluted composite insulators increases with the increasing of SDD. Under the same pollution conditions, the critical flashover current$(I_{c})$ of ice covered insulators is larger than that without icing. The critical flashover current and equivalent salt density of insulators are also exponentially correlated. The characteristic exponent(e) of the insulators without icing and with ice layer thickness of 5mm, is 0.343 and 0.356, respectively.