Investigation on electric and dielectric behavior of magnetite doped nanofluids

This attempt aims at developing a new class of insulating liquid by incorporation of nanoparticles to improve electric and dielectric properties of conventional fluids, which would result in miniaturization of oil-filled high voltage components at reduced costs. Material at nano level tends generally to attract each other leading to agglomeration, because of Van-der-Waals forces, which is the main challenge in preparation of nanofluids. Therefore, a lot of care has been paid to achieve a stable multiphase suspension by modifying the surface of the nanoadditives with an appropriate surfactant. In this research, nanofluids are produced by homogenous dispersion of ironoxide nanoparticles in ester liquid at diverse concentrations. Thereafter, the prepared suspensions are submitted to ultrasonic waves to break down the cluster of nano-sized constituents and consequently to achieve a homogenous distribution of nanofillers. The morphology considering the form and size of the additives is studied via the transmission electron microscopy (TEM). In order to scrutinize the electrical performance of the modified fluids, breakdown voltage of nanofluids is measured by applying a sinusoidal voltage. Moreover, dielectric dissipation factor of the samples is determined at different temperatures and frequencies in order to investigate the influence of degree of enrichment. Furthermore, the partial discharge behaviour of the magnetite doped nanofluids is investigated.