A flashover prediction method for contaminated insulators using a stochastic analysis of leakage current

In this paper, we present the results of a new stochastic analysis of the leakage current on contaminated insulators under salt fog conditions. The stochastic analysis of the leakage current was conducted using a Hilbert transform and the level crossing rate. The Hilbert transform is used for the leakage current envelope, while the level crossing rate is used to convert the upper envelope into a cdf. Using a new defined weighting factor, the resulting cdfs show a probability that the stages until flashover can be discriminated from each other. Therefore, the proposed method is effective for flashover prediction and for monitoring the contamination conditions of outdoor insulators.