Dielectric characterization of palm kernel oil ester-based insulating nanofluid

This work presents a study on the dielectric and breakdown characteristics of nanofluids prepared from the palm kernel oil ester to examine the influence of nanoparticles on the dielectric loss and its compatibility with Kraft paper. The relative permittivity, dielectric loss, and high voltage DC conductivity of the nanofluid samples were studied with varying weight percentages of Al2O3 nanoparticles ranging from 0.2 wt% to 1 wt% to understand the behavior of the material and explore its adequacy as an electrically insulating fluid in oil-filled HV electric equipment. The dielectric loss was observed to decrease by an order of magnitude with 1 wt% Al2O3 nanoparticles. Measurement of DC electrical breakdown voltage of the ester-based nanofluids revealed that the dispersion of nanoparticles in the fluid result in an increase in the breakdown voltage of the base fluid with the optimum value obtained at 0.6 wt%. The presence of nanoparticles in the ester-based insulating fluid did not seem to have any adverse effect on the breakdown strength of the Kraft papers. The study indicated a decrease in the dielectric loss of the nanofluid when compared with the base alkyl ester and with improved breakdown voltage. The dielectric behavior of Kraft paper impregnated with the nanofluid samples displayed comparable insulation properties.