Assessment on the AC breakdown voltages of liquid insulation system

Liquid insulation plays an important role for the lifespan of the oil-filled transformer. Liquid insulators not only insulate the live parts of the transformer, but also act as cooling agent for better heat agglomeration when the transformer being energized. Petroleum-based mineral oil has become dominant transformer oil for more than a century for its excellent dielectric properties. Considering the source is derived from nonrenewable energy, researchers have been putting up efforts to develop a comparable or better substitutions for conventional transformer oil. Palm oil and coconut oil are the examples of potential alternative transformer oil for its advantage whereas it is derived from environmentally friendly sources and also renewable. However, before these type of oil can be implemented in service transformer, it is crucial to examine the behavior of the electrical properties which is the most important parameter; the AC breakdown voltage. Thus in this study, the breakdown voltage of palm oil and coconut oil are investigated. Result indicates that palm oil and coconut oil have fairly similar AC breakdown strength and withstand voltages. However, palm oil possess higher deviations in data compared to coconut oil that will make it less reliable in withstand voltage prediction.