Enhancing Breakdown Voltage of Transformer Oil Using Nanoparticle Additives: A Comparative Study of SiO₂, TiO₂, and Al₂O₃ Nanofluids

The dielectric strength of transformer oil is critical for the reliable operation of high-voltage equipment. In the present work, the enhancement of Breakdown Voltage (BDV) in transformer oil was investigated by dispersing Silicon Dioxide (SiO₂), Titanium Dioxide (TiO₂), and Aluminium Oxide (Al₂O₃) nanoparticles. All such nanofluids were developed at the optimal concentration available and tested for BDV enhancement, thermal conductivity, and dispersion stability. The results of the experiments indicated that all three nanomaterials exert a substantial improvement in BDV, with the maximum value belonging to SiO₂ at 45 %, due to its optimal electron scavenging capability and high chemical stability. Titanium dioxide (TiO₂) contributed to a significant improvement, while aluminium oxide (Al₂O₃) exhibited the highest thermal conductivity among all the fluids evaluated. Based on a strict comparison, SiO₂ was the most suitable nanoparticle among all the particles that were tested for dielectric enhancement due to its better BDV performance and stability. The research justifies the use of nanofluids as the insulating medium of the transformer in the future with higher reliability and operation efficiency. Major Findings: The study found that adding nanoparticles to transformer oil significantly improves its Breakdown Voltage (BDV), with SiO₂ showing the highest enhancement (26.7 %) and excellent dispersion stability. TiO₂ also improved BDV moderately but required precise concentration control, while Al₂O₃ contributed mainly to thermal conductivity rather than dielectric strength.