Abstract

The Breakdown Voltage (BDV) and the physicochemical properties of nanofluids based on African Canarium (Canarium schweinfurthii) and African plum (Dacryodes edulis) were evaluated to ascertain their suitability as transformer oils. The fruits were purchased from the local markets and extracted using the Soxhlet apparatus. The oils were then purified to remove any impurities that would make them unsuitable for electrical insulation in the high-voltage power equipment. The oil samples were then divided into five 100 ml samples each, and four of them were treated with TiO₂ nanoparticles at 0.01wt% to 0.04wt% TiO₂ nanoparticles, respectively. The BDV of the pure ester were determined to serve as the baseline, and the BDV of the samples treated with nanoparticles were measured. The samples treated with 0.03wt% TiO₂NPs recorded the highest BDV of 59.40kV at 60 ℃. The significant enhancement in the BDV of the Canarium and Dacryodes-based nanofluids recorded in this study is influenced by multiple mechanisms (such as trapping free electrons by nanoparticles, Maxwell-Wagner-Sillars polarization, and suppression of streamer initiation). The key physicochemical properties, such as density, viscosity, sludge formation, moisture content, acidity, flash point, and pour point of this mixture (i.e., 0.03wt% TiO₂NPs) were also determined. These key physicochemical properties were within the acceptable standard of IEC and IEEE, suggesting that the properties are technically viable to replace conventional mineral oil. The results of the physicochemical properties also demonstrate that the Canarium and Dacryodes-based nanofluids are safe, thermally stable, electrically reliable, and suitable for long-term use in high-power systems.

Keywords:Breakdown voltage; Physicochemical properties; Canarium-based nanofluids; Dacryodes-based nanofluids