MODELING OF THE AC ARC-DISCHARGE ON ICE SURFACES

A model for predicting the flashover voltage of ice-covered insulators energized with ac voltage is presented in this paper. The model takes into account the variation of ice surface conductivity as a function of freezing water conductivity. The effects of the length of the are o n its own characteristics, as well as the ac are reignition condition, were determined in a laboratory investigation using triangular ice sa mples. The model is applied to a short string of 5 IEEE standard insul ator units. There is an excellent concordance between the 50% flashove r voltage calculated From the mathematical model and the experimental results.