Computer Simulation of Leakage Current on Ceramic Insulator under Clean Fog Condition

During operation, ceramic outdoor high voltage insulators may severe a certain degree of pollution which may reduce their performances. Under these conditions a large leakage current (LC) may flow on the surface and degradation may take place. The LC waveforms are normally non-pure sinusoidal. This paper explains the LC under clean fog condition and proposes an equivalent electrical circuit model for modelling leakage current phenomenon on ceramic outdoor insulator under various environmental conditions. The proposed equivalent electrical circuit model consists of capacitor(s), non linear resistors (s) and sparks model(s). These three parameters are used to simulate the LC waveforms of ceramic insulator under various environmental conditions. Using the proposed equivalent circuit parameter on the LC waveform characteristics such as its magnitude, asymmetrical and total harmonic distortion (THD) are discusses. The leakage current simulation was done using ATP/EMTP software package.