A study on the Breakdown Characteristics of Natural Ester Based Nanofluids with Magnetic Iron Oxide and SiO2 Nanoparticles.

In the present study, the dielectric performance of two natural ester matrix nanofluids, are studied. Colloidal magnetic iron oxide and SiO 2 nanoparticles were properly dispersed in natural ester oil FR3 and the AC breakdown voltage was investigated. The experimental data reveal an increase of the breakdown voltage of the nanofluid with colloidal magnetic iron oxide conductive nanoparticles. On the contrary, in the case of non conductive SiO2 nanoparticles the breakdown voltage was reduced. For the explanation of the experimental results the potential well distribution of the two nanoparticles was calculated. Both the experimental results and the theoretical calculations show that conductivity and permittivity of nanoparticles play fundamental role in the behavior of nanofluid. Nanoparticles with different conductivity or permittivity than those of matrix oil enhance breakdown voltage strength while the insertion of nanoparticles with conductivity and permittivity comparable to those of matrix oil translates into the reduction of breakdown voltage. Introduction