Behavior of Creeping Discharges Propagating Along a Pressboard Immersed in ZnO-Based Nanofluid of Monoesters

This article investigates the propagation of creeping discharges on pressboard immersed in ZnO-based nanofluid of monoesters of palm kernel oil (PKOME) and castor oil (COME). The experiment was conducted for three concentrations of nanoparticles (NPs): 0.10, 0.15, and 0.20 wt.%. The tests are conducted under positive lightning impulse voltage. The analysis is based on the calculation of the radial occupancy density of the discharge and on the calculation of their maximum extension. The results show that although the propagation of discharges is less in COME than in PKOME, the addition of NPs produces a better regression of the impact of discharges with PKOME. For an applied voltage of 60 kV for example, the regressions of the discharge occupancy densities are 46.16%, 69.22%, and 42.88%, respectively, for the concentrations 0.10, 0.15, and 0.20 wt.% in PKOME compared with 37.94%, 53.03%, and 31.18%, respectively, in COME. For the maximum extension of discharges at the same voltage and concentrations, these results are 16.87%, 20.60%, and 8.19%, respectively, in PKOME compared with 15.74%, 17.17%, and 6.62% in COME. On the basis of the results obtained and those of previous work, it was concluded that the addition of NPs to the monoesters studied gives them a discharge attenuation capacity at least equal to that of mineral oil (MO), if not better.