Dielectric breakdown performance of mineral oil and palm fatty acid ester oil mixture blended using ultrasonic homogenizer

Mineral oil is a petroleum-based oil which is nonrenewable and is running out in the future. It is also non-biodegradable, thus, it can be harmful to the environment when there is oil spillage. Therefore, this work is conducted with an intention to reduce the usage of petroleum-based oil by mixing it with natural ester oil. This is achieved by mixing the mineral oil (MO) and palm fatty acid ester (PFAE) oil with a ratio of 20:80 and vice-versa by using homogenizer machine. Through the homogenizing process, each mixing sample is vibrated for 20 minutes to complete the miscibility of both insulating liquids. AC breakdown voltage test compliance with ASTM D1816 standard is conducted on the oil mixtures to investigate their dielectric breakdown performance. Comparison is made with the virgin MO and PFAE that used as benchmark. The results suggest that the optimal breakdown voltage was obtained by blending an 80% MO with 20% PFAE to improve the dielectric breakdown performance of mineral oil alone.