An auspicious dielectric in high voltage engineering: Vegetable oil

Petroleum based mineral oils have been used for liquid insulation in high voltage equipment since long time ago. Despite the obvious popularity over time, these oils have been found to be lacking in property requirement and most importantly in their negative environmental impacts. Due to the increasing awareness and sensitivity regarding environmental concerns, there is a need for either an alternative or a total replacement since petroleum is one of non-renewable energy source and may be gone one day. In this research, vegetable oils which have been studied in order to investigate the potentiality and suitability which could be a replacement of mineral oil. However, the selection of a typical dielectric fluid depends on its physico-chemical and electrical properties beside the nature of the service it will perform. For the physico-chemical properties, the parameters investigated are density, kinematic viscosity, flash point, fire point and pour point. Then for the electrical properties are breakdown voltage, dielectric dissipation factor and relative permittivity. The study shows that the vegetable oil give preferable performance compared to mineral oil.