Impact of Nanoparticles' Size on the Dielectric Properties of Synthetic Ester Oil

This study investigates the effects of critical parameters, such as the nanoparticle size and concentration, on the AC breakdown voltage of the synthetic ester oil MIDEL 7131. SiC spherical nanoparticles with nominal diameters of 50 and 100 nm are employed to synthesize four nanofluids at weight percentage ratios of 0.002% and 0.004%. Experimental analysis reveals that smaller-diameter nanoparticles provide the greatest enhancement in breakdown performance, with the most significant improvement observed at the highest investigated concentration. These findings suggest that nanoparticles with smaller diameters create interfaces with more charge traps, thereby enhancing the dielectric strength as concentration increases.