Influence on voltage distribution of composite insulator by inserting metal electrodes in weather sheds

The uneven distribution of voltage along the composite insulator strings harmed their electrical and mechanical properties heavily, which threatened the safety of power system. Inserting metal electrodes in the silicone rubber sheds of composite insulator helps increase their self-capacitance, thereby ameliorating the voltage distribution along the string. In this paper, a new structure of weather sheds with metal electrodes inserted has been designed. Tests on composite insulators with different metal electrodes setup were conducted to examine their voltage distribution performance. Corona inception voltage of the mentioned composite insulators was obtained by a remote monitoring system as a criterion of the voltage distribution performance. Simulation model of the insulators were set up and calculation of their voltage and electric field distribution were carried out by finite element method (FEM). The calculation result was in good compliance with the experiment result. The applied voltage at the live end of composite insulator decreased by 4% when inserting electrodes in the weather sheds, which was verified by both experiment and simulation results.