Enhancing the Insulating and Thermal Reliability of Synthetic Ester Insulating Fluids Using SiC Nanoparticles

The growing need for eco-friendly insulating fluids in high-voltage systems has motivated the replacement of mineral oil with ester-based alternatives. The present investigation focuses on how SiC nanoparticles modify the dielectric behavior and thermal performance of synthetic ester-based nanofluids. Nanofluids containing 50 nm and 100 nm SiC particles at 0.002% and 0.004% w/w concentrations are prepared and characterized. The AC breakdown voltage and partial discharge inception voltage are experimentally determined according to IEC 60156 and IEC 60270, respectively, while thermal diffusivity and conductivity are also determined. The optimal composition (50 nm, 0.004% w/w) demonstrates an 18.8% increase in mean BDV and up to a 35.1% improvement at the 1% failure probability level, indicating enhanced dielectric reliability. Partial discharge measurements reveal a maximum PDIV increase of approximately 31% for the 50 nm formulation at 0.002% w/w. Thermal analysis shows enhancements of up to about 70% in thermal conductivity and around 62% in thermal diffusivity at 90 °C, confirming the multifunctional benefits of SiC addition. The results demonstrate that SiC-based synthetic ester nanofluids provide simultaneous electrical and thermal enhancement, promoting their use as next-generation eco-friendly insulating media for high-voltage equipment.