Effect of Fe<inf>3</inf>O<inf>4</inf> nanoparticle concentrations on dielectric property of transformer oil

Abstract

Nanoparticles have the potential to enhance the insulation conduct of transformer oil. The concentration of nanoparticles influences the breakdown vitality of mineral oil. In this investigation, mineral oil based nanofluids were prepared by scattering magnetic nanoparticles into transformer oil with different concentrations from 5% to 80% w/v. The AC and lightning impulse breakdown strengths of the oil samples with and without nanoparticles were investigated in accordance with IEC standard methods. The test outcomes indicate that addition of magnetic nanoparticles can enhance the insulation strength of transformer oil. With the increase of nanoparticle concentrations, the AC and positive impulse breakdown strength of transformer oil are first increased and up to the maximum value at the concentration of 40%. After which the breakdown strength start decreasing. The result of negative impulse breakdown showed that the breakdown voltage of nanofluids with multiple concentrations were lower than the breakdown strength of pure transformer oil. The probable modification mechanisms of Fe 3 O 4 nanoparticles on dielectric features of transformer oil were also reviewed.