Effect of Nanoparticles' Mixtures on AC Breakdown Voltage of Mineral Oil

Abstract

This paper aims at the experimental study of the influence of nanoparticles (namely Fe3O4, Al2O3 and SiO2) and nanoparticles' mixtures consisting of conductive (Fe3O4) and insulating (Al2O3 or SiO2) nanoparticles at various concentrations on the AC breakdown voltage (AC-BDV) of transformer mineral oil. The breakdown voltages at 1%, 10% and 50% cumulative probabilities are deduced. A statistical analysis of experimental results obtained with nanoparticles' mixtures is also performed using normal and Weibull distribution laws. Experimental findings show that the considered nanoparticles significantly improve the average AC-BDV. The improvement can reach 114%, 76% and 75% with Fe3O4, Al2O3 and SiO2 NPs, respectively. With mixtures of nanoparticles, namely (Fe3O4+Al2O3) and (Fe3O4+SiO2), at investigated concentrations, the average AC-BDV always increases. The best improvements are obtained with (20% Fe3O4+80% SiO2) and (20% Fe3O4+80% Al2O3), that is to say, 94% and 90%, respectively. These latter are better than with SiO2 and Al2O3 NPs when used singularly.