AC breakdown voltage of Fe3O4 based nanodielectric fluids. Part 1: Analysis of dry fluids

The interest in developing 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 to insulating liquids can lead to an improvement of their dielectric properties. This two-part paper analyzes the enhancement of the AC breakdown voltage of several nanodielectric fluids prepared by dispersing variable concentrations of Fe
₃
O
₄
nanoparticles in a mineral oil. In the first part of the study, the performance of fluids that had been previously dried and degasified were tested. In the second part of the study the impact of the presence of moisture in the dielectric strength of the liquids is analyzed trying to get insight into the physical mechanisms that justify the observed enhancements when nanoparticles are added to insulating liquids.