Three-dimensional electric field simulation and flashover path analysis of ice-covered suspension insulators

Flashover of ice-covered insulators seriously affects the safe operation of transmission lines. It is necessary to study the electric field distribution for flashover analysis of ice-covered insulators. The electric field of ice-covered insulators was mostly calculated by a two-dimensional (2D) axisymmetric model that cannot be well corresponded to actual icing situations. In this study, a 3D electric field simulation model of ice-covered suspension insulators under moderate icing condition with applied DC voltage was established. Two characteristic parameters, E-av and E-max were proposed to measure electric field distortion degree. Based on the simulation results, the effects of water film conductivity, icicle length, icicle deviation angle, and icicle distribution on E-av and E-max were studied. The results showed that icicles have a significant influence on the electric field distribution of insulators. E-av increases with the increase of icicle length and decreases with the increase of icicle deviation angle. E-max increases with the increase of the icicle length, icicle spacing and adjacent icicle length difference. When the icicle deviation angle is 45 degrees, E-max is the largest. Lastly, the possible flashover paths were analysed based on the simulation results, which would provide a theoretical basis for building a flashover model of ice-covered insulators.