COMPARATIVE ANALYSIS OF STABILITY AND DIELECTRIC BREAK DOWN STRENGTH OF TRANSFORMER OIL BASED NANOFLUIDS

Transformer oil is used as insulating as well as heat transfer liquid. If it is used for a long time it may loses its insulation and heat transfer characteristics. Nanofluids are the recent generation heat transfer fluids which are made by dispersing the nanoparticles in the required proportion to improve its properties. In the present study, breakdown strength and stability are measured for transformer oil based SiO2, Al2O3, TiO2 nanofluids for various concentrations. It is observed that the breakdown strength increases with increase in the nanoparticle volume fixation up to a particular concentration and then it starts decreasing. Among the three types of nanofluids, transformer oil-Al2O3 nanofluid got the better performance in terms of breakdown strength and stability in terms of zeta potential value. Transformer oil-Al2O3 nanofluid showed the superior improvement in breakdown strength 32 % i.e., from 50 kV to 68 kV at 0.06 % volume fraction and zeta potential value is increased from 22 mV to 28 mV which is 27%.