Partial discharge characteristics of palm fatty acid ester (PFAE) as high voltage insulating material

The world´s energy requirement has been dominated by petroleum-based oil for centuries in many application fields, including transportation, household, and electricity. Mineral oil as one of petroleum-based product; an important insulating material in power system has been used more than 150 years. Mineral oil application in power system equipment can be potentially hazardous to the environment especially when there are any incidents during operational time like transformer explosion, which may cause a spill of oil to the soil or water stream. Due to the concerns about the reducing petroleum resources and the environmental issues, the alternative insulating oil with biodegradable characteristics has been attracted lots of attentions for a couple of decades. The purpose of this research work is to investigate the partial discharge characteristics of palm-based oil, namely palm fatty acid ester (PFAE) as biodegradable oil for power transformer oil application. The characteristics then compared to other biodegradable oil, namely soybean-based oil and commercially available mineral oil for further analysis. The effect of electrical stress and ageing time on the oil samples were performed in this work. The results revealed that the partial discharge characteristics of PFAE are similar with commercially mineral oil. Particularly, PD magnitudes of PFAE are slightly lower than those of mineral oil samples during the ageing time. Therefore, PFAE has a good potential to be used as power transformer oil in electrical power system application.