Dielectric properties of transformer oil based silica nanofluids

Nanofluids are prepared for use in high voltage engineering as insulating and heat transfer fluids, containing a small amount of nanoparticles. The term “nanofluid” was presented by Choi et al. at Argonne National Laboratory. Recently, nanofluids are being considered as next generation insulating and heat transfer liquids in due to their improved characteristics. Transformer oil-based nanofluids are being studied as an alternate for conventional mineral oil. In this paper, transformer oil-based silica nanofluids with different concentration (10% and 20%) were prepared. The AC breakdown strength of nanofluids was measured at high moisture level 20ppm. Nanofluids showed improved breakdown strength at high concentration and there was only a negligible effect on breakdown strength at low concentration.