Effect of Aging on the Dielectric Performance of Synthetic Ester-based Nano-oils

The service life of a transformer primarily depends upon the aging characteristics of the insulating material. This study is performed to enhance the anti-aging ability and dielectric performance of synthetic esters using nanoparticles. Synthetic ester is basically emerging liquid insulation for transformers. The experiment for accelerated aging is performed on a thermal aging setup that provides an oxidative environment similar to a transformer. Three different concentrations of ZnO and CuO nanoparticles are used to prepare nanofluids using a two-step method. The AC breakdown test is performed according to IEC-60156 experimental standards. The dissipation factor and resistivity of oils are determined according to the IEC-60247 testing standard. A comparison of un-aged synthetic esters with aged nanofluids is performed. The nanofluids show significant changes in AC breakdown voltages. However negative influence on the dielectric property was observed due to dielectric losses associated with synthetic esters, which limits its application.