Natural Ester Oil-Based High Permittivity CaCu3Ti4O12 (CCTO) Nanofluids an Eco-Friendly Insulating Medium for Power Transformer

Natural ester oils are being considered as an alternative and eco-friendly insulating medium presently preferred by the power industry for power transformer application. This work deals with the development of natural ester oils like rice bran and sunflower oil (SFO)-based high permittivity CaCu3Ti4O12 (CCTO) nanofluids in different volume concentrations. The investigation of dielectric and physico-chemical properties is performed in accordance with ASTM and IEC standards. The enhancement of ac BDV is found at 45% in rice bran oil-based CCTO nanofluid. Increments in dielectric permittivity, decrement in loss tangent, PDIV, and dc resistivity are the common factors observed in both the ester oil samples. Also, flash point and thermal conductivity properties showed enhancement with an increment of volume fraction loading. Hence, due to the optimum dispersion of nano-CCTO loading at
$\le 0.01$
% in both the base oils of rice bran and SFO, remarkable enhancement is achieved in both the nanofluid samples to develop an eco-friendly insulating medium for power transformer application.