Assessing Contamination Severity of High Voltage Insulators Using Dielectric Loss Factor: Laboratory Measurements and Comparative Analysis of Leakage Current and Dielectric Loss Factor at Different Voltage Levels, Humidity, and Insulating Materials

This study investigated the dielectric loss factor and leakage current measured on glass and porcelain insulators at different levels of contamination and humidity. The dielectric loss factor and leakage current were measured at an industrial frequency of 50Hz using an independent low THD voltage source to eliminate interference from the power network. The results showed that the dielectric loss factor was only slightly affected by changes in applied high voltage, while the leakage current was highly dependent on changes in applied voltage. Both parameters appeared to be sensitive to changes in relative humidity and contamination levels. These findings have practical implications for the diagnosis and maintenance of high voltage insulators.