Effect of shape of insulator housings and positions of composite insulators on ageing resistance under high voltage and precipitation

This paper outlines the results of investigations on the ageing deterioration of model composite insulators where the slope angles of their sheds equal 0, 10 and 30 degrees. It also describes how their vertical, horizontal and oblique working positions affect the manner of their surfaces moistening under conditions of simulated rain and fog water precipitation. It is demonstrated that how the surfaces of insulator sheds are moistened substantially affects time-dependant variations in leakage currents and the energy of electric discharges on the insulator surfaces. Proof is provided that deviations of insulators from their vertical working positions towards the horizontal lead to a growth in leakage currents of insulators. It was also found out that a steeper slope angle of the insulator shed substantially improves the ageing resistance of the devices operated at various working positions under conditions of high voltage and rainwater or fog precipitation.