Influence of Concentration of Nanoparticles on the Dielectric Frequency Response of an Insulating Nanofluid

Abstract

Liquid insulation is employed in transformers along with the solid insulation for the reliable operation. The transformer insulation has technologically advanced over time and a number of varieties are explored. Every insulation is found to have some or the other advantages and disadvantages. The application of a particular liquid insulation is chosen based on its properties. Among the insulating oils being studied for transformer application, nanofluids are delivering promising electrical and thermal characteristics compared to the base oils. The dielectric frequency response is one of the non-destructive and offline technique to analyze a few dielectric properties of the insulating oil and it is used to estimate the moisture content of pressboard and the conductivity of the insulating oils, unlike the power frequency test which can only be used for estimating the contaminants. The frequency response is observed over a wide range of frequencies. The low frequency response is very much crucial in characterizing the dipole moment as it is significant at lower frequencies. In this paper, the concentration of the insulating nanoparticle in base oil is varied and the frequency response, polarization, and conductivity are studied at room temperature. The response is a depiction of the condition of the liquid insulation. The conductivity, relative permittivity and the dissipation factor are plotted. All these parameters are in the frequency range from 1 mHz to 10 kHz, which is the suitable range to study the liquid insulation.