Effect of MgO Nanoparticles on the AC Breakdown Voltage, Partial Discharge Activity, and Electrostatic Charging Tendency of Natural Ester

This article deals with the effect of MgO nanoparticles (NPs) on the ac breakdown voltage, partial discharge (PD) activity, and electrostatic charging tendency (ECT) of natural ester (NE, Midel 1204). Five concentrations of NPs ranging from 0.1 to 0.5 g/L are tested; the average size of NPs is 20 nm. A new method for preparing nanofluids (NFs) is presented; this includes a combination of high-shear (HS) mixing and ultrasonication. The findings show that the inclusion of MgO NPs in NE leads to an enhancement in ac BDV across all concentrations except at 0.5 g/L. The most significant improvement is observed at a concentration of 0.2 g/L, with an increase of 21.85% compared to NE. This optimal concentration enables one to reduce effectively the average charge, peak charge, and number of PDs per second of PD events while maintaining a lower level of ECT.