Experimental Analysis of Some Natural Esters and Their Mixtures for Transformer Application

The transformer can be called the heart of the power system network. Transformer has an important role in raising or lowering the voltage to a reasonable level in different stages of the power system such as generation, transmission and distribution. Therefore, the life of the transformer is very important in the power system, which mostly relies on its insulation condition. Two types of insulation are mainly used in transformers, first in solid form i.e. pressboard and Kraft paper etc. and second in liquid form i.e. mineral oil. Since mineral oil is a petroleum product and due to its limited sources in nature, it will not be available to us in the near future. The use of mineral oil is also harmful to the environment and human life. Natural esters, which are the vegetable product, are renewable, easily biodegradable, nontoxic and environmentally friendly, so they can be considered as a better alternative of mineral oil. Natural esters are vegetable oils such as soybean oil, sunflower oil, canola oil, palm oil etc. which are abundant in nature. The electrical and thermal properties of natural esters have proven to be better than mineral oil. This paper gives an experimental analysis of two different natural esters, canola oil, soybean oil and their mixtures, which is based on some important physical, chemical and electrical parameters of an insulating oil.