An analytic model to simulate leakage current of a snow-covered insulator

摘要

In this paper an analytic model allowing simulating the electrical characteristics and the leakage current of a snow-covered insulator is proposed. For that purpose, leakage current through a snow-covered insulator was monitored under high alternative voltage at a temperature of - 12℃. From the measured voltage-current characteristics, it was found that the voltage across snow and the leakage current flowing through the snow-covered insulator were almost in the same phase. However, the resistance of snow was found to be non-linear, as it decreases with an increase in voltage across snow. Based on the experimental results, a mathematical model enabling to simulate the leakage current was elaborated. This model shows that the leakage current through snow can be expressed as an exponential function of the voltage across snow, depending on the density and conductivity of the water melted from the snow. The comparison of results obtained by the analytical model and those by experiment shows a good correlation.