State transition analysis of artificial contaminated test discharge based on leakage current

Studying and exploring variance regularity of the current signal in the process of contamination flashover development is important and helpful for developing flashover on-line monitoring system and studying mechanism of surface flashover in advance. In this paper, five statistical index computed from leakage current envelope such as mean, standard deviation, kurtosis, skewness and third harmonic distortion factor were selected as analysis objects. Through considering them as samples from five random processes, the one-step state transition matrix of the random processes was calculated and the state transition process was analyzed. The results show that surface arc discharge process has some statistical regularity, and single index can't recognize discharge state. The research methods and ideas in this paper were helpful for advanced research on discharge process, setting up its model and study on anti-contamination flashover technology in the future.