Investigations on the Impact of Nanoparticles on the Performance of Natural Ester Based Dielectric Coolants for Power Transformer

Mineral oil has been a liquid dielectric for over a century because of its good dielectric properties. Mineral oil (MO) and synthetic ester based nanofluids are more popular in research field and also proven to have excellent improved dielectric properties [1], [6], [7]. However, mineral oil is non-bio friendly, highly depleting in nature, and carcinogenic (in the event of an accidental spill), which has led to the development of eco-friendly, non-carcinogenic vegetable oils that are also renewable in nature. This paper investigates nanofluids used as liquid dielectrics for transformers. In this work, two nanofluids codenamed, RNF2 and SNF2 have been prepared using the nanoparticle TiO2 with two natural esters as base fluids and codenamed as IRBO and ISO. This paper mainly focuses on the preparation of nanofluids for different concentrations and also investigations on AC BDV behavior and dielectric properties (dissipation factor, electrical permittivity and resistivity). The nanofluids RNF2 and SNF2 have shown encouraging results as compared to their base oils. The best among the concentrations prepared are 0.002% for both RNF2 & SNF2 giving 65.725% & 48.02% improvement in BDV respectively, compared to their base oil. The dielectric properties under power and high frequencies are also good as per recommended standards.