Requirements and Expectations of Natural Ester Fluids for Application in Power Transformers

Natural ester seed oil is a biodegradable fluid that is increasingly being used as a replacement for mineral oil and for high temperature flashpoint liquids, including silicone and RTEMP. This paper addresses technical issues that need to be answered in introducing a new dielectric insulating and cooling fluid for distribution and power transformers. The author's experience and training in large power high voltage transformers gives him particular insight into the dielectric, thermal, and physical issues that must be addressed