Synthetic and natural ester-based nanofluids with fullerene and magnetite nanoparticles-An experimental AC breakdown voltage study

Ester-based electrical insulating liquids constitute an attractive alternative to widely used mineral oils, especially due to their ecological benefits. In this study, we present an experimental comparison of AC breakdown voltage (BDV) in both natural and synthetic ester-based nanofluids with various concentra-tions of fullerene (C60) and magnetite (Fe3O4) nanoparticles. The BDV measurement was conducted with an AC voltage rise rate of 2 kV/s according IEC 60156 standard. While the suspensions of magnetite nanoparticles exhibited increased AC BDV for all samples tested, the fullerene-based nanofluids exhibited the enhanced AC BDV only for two among six nanoparticle concentrations. Accordingly, we present a comparative view of the electrical breakdown development using statistical descriptors. This study uses Weibull and normal distributions for statistical analysis to estimate AC breakdown voltage at different cumulative probability levels 1 %, 10 %, and 50 %. The parameters of theoretical distributions are fitted to the experimental data. Subsequently, statistical test of conformity to the distributions, and their skew-ness and kurtosis are analysed. The analysis reveals that AC BDV of nanofluids increases with the increas-ing cumulative probability more than those of pure esters. It is shown that the addition of fullerene nanoparticles tends to reduce AC BDV in the natural ester but not in the synthetic ester. The presence of magnetic nanoparticles in both esters yielded an enhancement of the AC BDV but in a different measure.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study presents an experimental comparison of AC breakdown voltage in natural and synthetic ester-based nanofluids with fullerene and magnetite nanoparticles. Statistical analysis shows that the AC BDV of nanofluids increases with increasing cumulative probability. Fullerene nanoparticles tend to reduce AC BDV in natural ester, while magnetic nanoparticles enhance AC BDV in both esters, though to a different extent.