Modeling of Flashover on Ice-Covered Insulators with Multi Air Gaps

Using a standard porcelain post insulator, the flashover process on an ice surface was simulated and analyzed. Based on the experimental results, a mathematical model for predicting the critical flashover voltage of ice-covered insulators with multi-arcs is presented. The model was applied to a post insulator with a dry arcing distance of 4.17 m, corresponding to the full-scale insulator string used in the Hydro-Quebec 735 kV substations. It was found there is good agreement between the experimental results and those from the mathematical model. The results obtained are helpful for properly selecting the insulators used in cold climate regions