Enhancement of Physical and Electrical Properties of Mustard Oil by Adding TiO2 Nanotubes for Power Transformers

Mineral oil is the most commonly used insulating oil in power transformers due to its low cost, universal availability and high dielectric strength. The potential of vegetable oils to serve as an alternative to the conventional mineral oil for power transformers is being considered due to its better dielectric strength and high biodegradability. Furthermore, the addition of small quantity of nanotubes to vegetable oils has the potential to considerably enhance their dielectric strength. In this paper, a detailed experimental investigation on the dielectric characteristics of Mustard oil infused with Titanium dioxide (TiO2) nanotubes has been carried out. The investigation covers the analysis of physical properties including moisture content, specific gravity, pour-point, flash point, viscosity, and acidity. Additionally, the breakdown strength and partial discharges of Mustard oil and nanofluid were also examined. All the tests were performed according to ISO and IEC standards. The detailed characterization of nanotubes was investigated with the help of X-ray diffraction and Scanning Electron Microscopy. The TiO2 nanotubes were mixed with pure Mustard oil at the concentration levels of 0.02g/L, 0.05g/L, and 0.1g/L. The experimental results indicate that the nanofluid with a concentration of 0.05g/L exhibits better properties compared to the other samples in its potential as a replacement of the traditional mineral oil. The investigation also revealed that the AC breakdown voltage increased by approximately 40%, whereas a three-fold rise in the partial discharge extinction and inception voltages was observed when 0.05g/L TiO2 was added into the Mustard oil compared to the pure mineral oil. A comprehensive evaluation of the dielectric properties of this mixture, in comparison to the mineral oil and other vegetable oils, underscores its cost-effectiveness as a viable alternative for power transformers. Hence, the addition of 0.05g/L TiO2 nanofluids into Mustard oil can be considered as a practical and economically feasible substitute to both mineral and vegetable oils.