The Effect of Harmonic Distortion Voltage to Partial Discharge Characteristics in Epoxy Insulation

Abstract

Harmonic distortion affects insulation systems in terms of losses, lifetime, and dielectric material degradation. As the number of harmonic-producing loads increases over years, it has become increasingly necessary to address their influence on voltage supply. Partial Discharge (PD) is a localized dielectric discharge that may occur in a particular area of a solid or liquid electrical insulation system under high voltage. It may happen due to imperfection in the insulation system. Partial Discharge measurement gives an early indication of a decrease in the insulation system’s quality. Hence, the correlation between the harmonic content and partial discharge properties should be defined to reflect the partial discharge condition properly. This research focused on observing the repetition rate and the apparent charge of a Partial Discharge pulse when the voltage input contains harmonic distortions. The harmonics distortion will be adjusted in level and order of harmonic distortion. The resulting harmonic distortion is in individual order of third, fifth, and seventh harmonics, and their combination. The total harmonic distortion (THD) level was set in three variations, which were three, seven, and ten percent of THD. A personal computer (PC)-based signal generator was used to generate the voltage harmonic distortion. Partial Discharge data were collected for the inception of the Partial Discharge detected. The test object used was Epoxy Resin isolation. It was placed between needle-rod electrodes. The result shows that the distorted voltage can affect the pulse repetition rate, the PDIV (partial discharge inception voltage), and the apparent charge of Partial Discharge pulse.