Investigating the Effect of Nanofillers on the Electrical Conductivity of Dielectric Liquids and Their Impregnated Pressboard

The present work is a study on the electrical conductivity of different transformer insulating materials, namely mineral oil, synthetic ester, natural ester, and their impregnated pressboards, with and without nanofillers. The comparison of the electrical properties is made at four different temperatures of 30, 50, 70 and 90°C. Electrical conductivity measurement on nanofluids prepared using Alumina nanoparticles and press-boards impregnated with these nanofluids is also performed. The ester liquids and their impregnated pressboards have electrical conductivity higher than that of mineral oil and its impregnated pressboard. However, with nanoparticle addition, the electrical conductivity of mineral oil is significantly higher than ester liquids. Increase in temperature also contributes more to this change in electrical conductivity in mineral oil than ester liquids.