AC Dielectric Strength in Natural Ester and Natural Ester-Based ZnO, TiO₂ and CuO Nanofluids

This paper aims to investigate the AC breakdown voltage (AC BDV) in Envirotemp FR3 natural ester (NE) and three NE-based zinc oxide (ZnO), titanium dioxide (TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) and copper oxide (CuO) nanofluids (NFs) at different concentrations (0.05, 0.1, and 0.2 g/L). The AC BDV was measured using a horizontally positioned sphere-sphere electrode configuration based on the IEC 60156 standard to ensure the reliability of the results. The collected data were analyzed with the Weibull and normal distribution functions, facilitating the estimation of breakdown voltages at 1%, 10%, and 50% probability levels, which are crucial for designing power electrical components. It appears from the experimental results that the influence of nanoparticles (NPs) on the AC BDV of nanofluids depends on the nature, dimensions, and concentration of NPs. The results show that adding specific nanoparticles leads to the slight improvement/deterioration of AC BDV, and there is an optimal concentration for which the improvement is the highest.