Critical conditions of AC arc propagation on ice surfaces

The critical condition of AC are propagation on ice surfaces was investigated and the arc maintenance condition was determined. It was found that the local are established along the air gap could enlarge as the air gaps enlarge with ice melting and falling down. When the critical length of local are along the air gap was obtained, it propagated on the ice-surface until the flashover occurred. It was also found that the arc maintenance condition depends on the ice sample length. The results obtained allowed to improve our previous model, developed for predicting the critical flashover voltage of ice-covered insulators