The Analysis of Leakage Current on a 20-kV Silicone Rubber Post-Insulator under Dry and Wet Conditions

Silicone rubber material has not been commonly used in the manufacturing of a post insulator. As the installation of this insulator type is normally in an open space, it is greatly vulnerable to the influence of weather and environment, such as humidity, rain water, lightning strikes, temperature, ultraviolet radiation, and others. Leakage currents flowing on its surface may become the source of power losses. This article presents the results of research on the effect of voltage and wetting intensity on the leakage current level of a 20-kV silicone-rubber post-insulator. The leakage current has been observed under dry and wet conditions. The experiment has been conducted using the voltage level variation of 5 kV in the range between 10 kV and 30 kV, using four variations of wetting intensity. Comparison of the experiment results showed that unlike under the dry condition, the resulted leakage current under the wet condition increased nonlinearly with the increase in the wetting intensity and the voltage level.