Impact of Oil-Based Nanofluids on Partial Discharge Activity

Abstract

Oil-based nanofluids have an enhanced breakdown strength compered to mineral oil. However, their partial discharge (PD) characteristics under non-uniform fields need more investigation. In this study PD activity of oil based nanofluids was studied and compared to that of base oil. The selected nano modifier was Titanium oxide (TiO 2 ) with low weight fraction. The nanofluids sample was prepared via ultrasonic processing. Regarding the PD measuring system, a needle-plane electrode was manufactured with an oil gap spacing of 3mm. The comparison includes both partial discharge inception voltage (PDIV) and PD propagation at different levels of applied voltage. First, the probability of the measured PDIV was evaluated using Weibull distribution and average inception was calculated. Then, the number of PD pulses was calculated for both negative and positive polarity of applied voltage. In addition, the phase appearance of PD pulses was analyzed. Moreover, the time transition of PD pluses for 10 min time domain was depicted. It was found that partial discharge pulses appear around the peak of the applied voltage for both nanofluid and base oil. Based on the obtained results, the role of nanoparticles in PD activity is discussed based on the initial electron generation and propagation.