Analysing the impact of Moisture on the AC Breakdown Voltage on Natural Ester Based Nanodielectric Fluids

The interest in the development of new nanodielectric fluids suitable for electrotechnical applications has increased significantly in the last decade. Several authors have reported experiences on fluids manufactured using different base fluids and nanoparticles. Most of these studies are focused on the comparison of the thermal and dielectric properties of the nanofluids and the base liquids and most authors have found that the addition of nanoparticles can lead to an improvement of the properties of insulating liquids. The main objective of this paper is to study the enhancement of the ac breakdown voltage (AC BV) at 50 hz achieved when dispersing nanoparticles (NP) in transformer oil. In particular, transformer natural ester was used while the nanoparticles used were Fe₃O₄ dissolved in a hydrocarbon base and carboxilyc acid. In order to obtain a good dispersion of the nanoparticles an ultrasonic agitator was used. The impact of moisture in the dielectric strength of fluids prepared with different concentrations of NP was evaluated and compared with that of the natural ester. The experimental results show a certain improvement of the dielectric strength of the nanodielectric fluid compared to that of the natural ester.