Investigations on the suitability of rice bran oil and corn oil as alternative insulating liquids for transformers

Abstract

Increasing power demand forces the development of the high‐rated power transformers. In a transformer, petroleum‐based mineral oil is used as insulation currently. Transformer oil (TO) produces environmental and health issues because it is nonbiodegradable. The availability of petroleum products is decreasing in the present century. So it encourages researchers to find potential replacements for them. In this work, two natural ester oils (rice bran oil and corn oil) were taken up for investigation to find their suitability for use in transformers. Aging analysis was performed on the TO and natural esters. For this, properties like breakdown voltage, flash point, fire point, viscosity, acidity, resistivity, and loss factor of the natural esters were considered. From the investigations, it was evident that rice bran and corn oil have the ability to be used as alternatives for TO. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.