AC and Lightning Impulse Breakdown Voltage Comparative Study of Mineral Oil-Based Fe3O4, Al2O3, and TiO2 Nanofluids

This article deals with the comparison of ac and lightning impulse breakdown voltage (LI-BDV) of mineral oil (MO)-based Fe3O4, Al2O3, and TiO2 nanofluids (NFs) in different low concentrations. A statistical analysis that was performed to evaluate the ac breakdown voltage at different insulation failure risks using Weibull and normal distributions, and the optimal concentration of different nanoparticles (NPs) at the range of 0–0.1 g/L under ac condition was determined. At the optimal concentration, the ac breakdown voltage at 1% insulation failure risk of three kinds of NFs is improved at least 20%, and especially, for TiO2 NFs, the increment of breakdown voltage reaches 60%. The effect of NPs on the breakdown of NFs is analyzed, and the possible charge capture and release processes are proposed. This study can serve as a reference for insulation design using NF as an insulating material.