Leader Propagation Model for Predetermination of Switching Surge Flashover Voltage of Large Air Gaps

Abstract

The breakdown voltage of an air gap submitted to switching surges may be predetermined by use of a mathematical model of leader propagation. This model is applied, in this article, to point plane gaps, for which a number of experimental results are available. It is possible to similate the development of a flashover: current, speed, visual appearence. U50 voltage and standard deviation may be deduced by simulation of test sequences and, as a result, the variations of these parameters, when the length of the gap and the shape of the applied wave vary, may be studied. Generally, results are found to be in accordance with experiments.