Aging Impact on Relative Permittivity, Thermal Properties, and Lightning Impulse Voltage Performance of Natural Ester Oil Filled With Semiconducting Nanoparticles

This study is focused on exploring the change in the dielectric and cooling efficiency of vegetable oil following the integration of semiconducting SiC and TiO2 nanoparticles (NPs) in two different weight percentages by comparing the corresponding behavior of nanofluids (NFs) at the time of their synthesis and after one month of aging. The thermal response has been evaluated by means of diffusivity and conductivity, while dielectric properties are measured with nondestructive tests (relative permittivity and dissipation factor) and destructive ones in terms of lightning impulse withstand voltage. The results of the latter property measurements are also compared to numerical model findings. The analysis of results proves that the properties under study are worsened with increase in NPs’ concentration, probably attributing it to quicker agglomeration, as it is also confirmed by the simulation results.