Experimental evaluation on the dielectric breakdown voltage of fresh and used transformer oil mixed with titanium dioxide nanoparticles in the Gilan electrical distribution company

This paper reports on experimental investigations dealing with the influence of titanium dioxide nanoparticles on the breakdown voltage of transformer oil. TiO₂ particles with the nano size could be synthesized by the sol-microwave method. The materials characterized by XRD, SEM and TEM techniques. In this study, we have measured the dielectric breakdown voltage of transformer oil-based nanofluids in accordance with IEC 156 standard. The concentrations of TiO₂ nanoparticles in transformer oil are in the range from 0.001 g/l to 0.01 g/l. These concentrations for fresh oil (before and after the physical purification) and used oils for about 4 and 15 years, evaluated separately and the results were compared. Experiment results indicated that the addition of TiO₂ nanoparticles to transformer oil can enhance its dielectric strength and the surface compositions of the TiO₂ nanoparticles play an important role in its dielectric performance. When the volume concentration of nanoparticles is above 0.003 g/l, the dielectric breakdown voltage decreases. Based on test results and Due to the weather conditions in Gilan that has about 80 percent humid, titanium dioxide can be increase the breakdown voltage of transformer oils in free of moisture as well as humidity conditions.