Effect of Fe3O4 and Al2O3 Nanoparticles on Creeping Discharges Propagating Over Solid-Natural Ester FR3 Interface Under Lightning Impulse Voltage

This paper aims to study the impact of conducting $(Fe3O_{4},2\theta nm)$ and insulating $(Al_{2}O_{3},20-30 nm)$ nanoparticles $(NPs)$ on the creeping discharges propagating over solid-liquid interfaces under positive lightning impulse voltage. Five nanoparticles' concentrations ranging from $0.1 g/L$ to $0.5 g/L$ are considered. First, the nanofluids preparation procedure is presented; it combines high-speed agitation and ultra-sonication. Then, radial creeping discharges were characterized by the Measurement of their stopping length $(L {f);}$ the stopping length characteristic versus the applied voltage is plotted. It is shown that the addition of $Fe3O_{4}$ and $Al_{2}O_{3}$ nanoparticles improves the resistivity against the propagation of creeping discharges at specific concentrations $(\theta.3g/L$ and 0.4 $g/L)$ in the case of $Fe3O_{4}$ nanoparticles and all concentrations in the case of $Al_{2}O_{3}$ nanoparticles. Compared to base liquid, the best performances are observed at $56 kV$ with $Fe3O_{4}$ nanoparticles $(L_{f}$ is reduced by 18.61%) at $0.3 g/L$ and $Al_{2}O_{3}$ nanoparticles $(L_{f}$ is reduced by 23.00%) at $0.4 g/L$ .