Ageing behavior of vegetable oil blends

Abstract

Due to concerns over the environmental impact of mineral oil, alternatives such as dodecylbenzene and vegetable oils have been proposed for high voltage applications. The ageing behavior of various vegetable oils has been previously investigated and it was found that oils offering the best ageing resistance were also the most expensive. The current work examines the ageing behavior of blends of sunflower and olive oil to see if the properties of the former, cheaper oil can be improved by the latter, more expensive oil. It was found that blends with 50 -75 % olive oil in sunflower oil could offer oxidation stability comparable to the pure olive oil and therefore could offer a more cost effective solution compared to using pure olive oil.

Review of Research Progress on the Electrical Properties and Modification of Mineral Insulating Oils Used in Power Transformers

“…Recent studies have shown that vegetable oils are completely biodegradable and pollution-free [125,126]. Treated plant insulating oil, such as sunflower oil, olive oil, and rapeseed oil, has the advantages of high flash point and large dielectric permittivity, so it is a good substitute for mineral insulating oil [127][128][129]. However, most vegetable oils possess high viscosity, pour point, and acid content after aging compared with those of mineral oil.…”