The Effects of Electrical Arc Aging on Dielectric Properties and Partial Discharge Patterns of Natural Ester from Palm Oil

Abstract

Transformer is not only exposed by thermal aging, which causes several disturbances during its operation. But it is also exposed by electrical faults which lead the aging or degradation of electrical insulation. Therefore, electric arc aging is one of the most important factors that should be considered. It is very important to analyze the effects of accelerated electrical aging on chemical, dielectric, and physical properties to the oil performance. This research is conducted in order to assess the performance of natural ester during electric aging. Natural ester oil was made by using palm oil. Before it is used as liquid insulation, the viscosity has been reduced through transesterification processes. A triple needle-plane was immersed to the ester oil, and high voltage alternating current was injected to create an electrical arc for several minutes. The applied voltage was varied at 16 kV, 20 kV, and 24 kV (AC) as well as the arc duration, which varied at 0, 5, 10, and 15 minutes. Several measurements such as resistivity, relative permittivity, dielectric losses, breakdown voltage, and partial discharge have been conducted to observe the aging performance. The experiment results show that longer aging duration and higher applied voltage will fasten the degradation of the oil.