The comparative study of physical and chemical properties of palm oil and mineral oil used in a distribution transformer

This paper represents the physical and chemical characteristics of palm oil compared with mineral oil as insulating liquid. Two identical single-phase transformers with rated 22000/230V 30kVA were designed and constructed. The first transformer used palm oil and the second transformer used mineral oil as dielectric liquid. The physical and chemical properties of new liquids were investigated before and during transformer operation. The physical properties and chemical properties such as interfacial tension, viscosity, moisture content, acidity, and corrosive sulfur of the liquid specimen were tested according to international standards. Then these liquids were filled in the transformer. After that, transformers were operated at 80 % of designed rated with inductor load for two years by which the temperature, current, and voltage were recorded every hour. Every three months, the liquid insulation was sampling from each transformer to be investigated as the same mentioned items. From the preliminary test results (six months after transformer operation), it can be concluded that palm oil is the potentially alternative liquid insulation for using in the transformer.