Studies on critical properties of vegetable oil based insulating fluids

Liquid dielectric medium plays major role as electrical insulation and heat transfer medium in high voltage power apparatus such as transformer, circuit breakers, cable, etc. More than 100 years petroleum based mineral oil is used as liquid dielectric medium. Even though they have better insulating and cooling properties, there are some issues related with environmental aspect. By considering environmental issues, many researchers are motivated on the way to develop new insulating medium. In this work, vegetable oils such as Punna oil, Rice bran oil, Palm olein oil, Gingelly oil, Sunflower oil, Neem oil, Caster oil, Mustard oil, Ground nut oil and Mughwa oil are studied for development of new insulating medium. The study is carried out with measurement of critical properties of oil such as breakdown voltage, flash point, fire point and viscosity. From the results, it is known that most of the investigated natural esters have better properties except viscosity.