Effect of Fullerene Nanoparticles on Creeping Discharges Propagating Over Solid-Liquid Interfaces Under Impulse Voltage

This paper aims to study creeping discharges in a natural ester, namely FR3, and FR3 - based nanofluid with fullerene NPs under positive lightning impulse voltage. The investigated concentration of fullerene is 0.3 g/L. Based on our previous work, the optimal concentration of fullerene (0.3 g/L) enabling to improve AC breakdown voltage and partial discharge activity, and to reduce the electrostatic charging tendency (ECT) level, is picked as a candidate for the comparison. For that purpose, the nanofluid sample is first prepared using the two-step physicochemical process, and then the stopping lengths <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{{L}_{f}}$</tex> of creeping discharges (or final lengths) are measured and compared in both liquids (natural ester and natural ester-based nanofluid). An interactive tool is developed to compute/deduce <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{{L}_{f}}$</tex> from the images. It is shown that, for a given applied voltage, adding nanoparticles to natural ester reduces the density of branches and/or their stopping length. In addition, the analysis of the evolution of the stopping length versus the voltage shows that fullerene nanoparticles could constitute an inhibitor for creeping discharge propagation in natural ester FR3.