Leakage current properties of field-aged RTV silicon rubber coated & uncoated ceramic insulators

Abstract

Insulators have often become the main factor of power system failures which leads to interruption of power system delivery. Thus, ensuring the insulators working properly is an indispensable thing to do. Leakage current (LC) monitoring on the insulators' surface is one of the ways to acquire the condition of insulators. This paper discusses the results of LC monitoring of field-aged ceramic insulators that have been installed in a coastal area of a relatively humid weather. As proven in previous research, RTV silicon rubber coat that is applied on the insulators' surface can reduce the magnitude of leakage current. Therefore, in this research both RTV silicon rubber coated and uncoated field-aged outdoor insulators are monitored from the year of 2012 to 2017 to see the consistency of the results along the aging. There are total eight LC waveforms are obtained from experiment results in four different years, each of RTV silicon rubber coated and uncoated insulators. These waveforms are further recreated through computer simulation using ATPDraw software in order to obtain electrical properties, such as capacitance, nonlinear resistance, and number of arc models. The LC properties that are monitored from the experiment results and become the keys to the computer simulations are LC magnitude, Total Harmonic Distortion (THD), and dominant harmonics.