Performance studies on dielectric and physical properties of eco-friendly based natural ester oils using semi-conductive nanocomposites for power transformer application

In recent years, the interests on ester-based insulating oil as replacement of mineral oil in large power transformers are growing remarkable manner because of its environmental impact. Green insulating natural ester oil derived from natural sources results in higher biodegradability, fire resistant properties and so on. This research work presents the evaluation of dielectric and physical properties in natural ester oil like sunflower oil (SFO), rice bran oil and corn oil using semi-conductive nanocomposites for different percentages of volume concentrations. The AC breakdown voltage (BDV), loss tangent, DC resistivity, viscosity, dielectric permittivity, flash point and fire point properties are examined as per ASTM and IEC standards. Astoundingly, it is found that use of nanocomposite fluids (NCFs) results enhanced BDV and fire point properties in SFO samples. Hence, ester oil-based NCF serves as a compromising alternative insulation medium for power transformer application.