Natural ester insulating oil, as a novel type of liquid insulation dielectric, with advantages of highly flammable and biodegradable, is an important direction for future environmental protection industry. Due to the physicochemical characteristics of natural esters, the natural ester insulating oil putting into operation of the transformer faced with more challenges. The current status and trends of natural ester insulating oil were described and the preparation methods of natural ester insulating oil were analyzed. The related research progress and applications of natural ester insulating oil were described from the aspects of electrical characteristics, physicochemical properties, aging characteristics, hydrophilicity, oxidation stability and biodegradability. Finally, the key issues that needed to be solved when the natural ester insulating oil put into operation of the transformer were discussed. |