Effects of Temperature on Electrical Treeing in Epoxy/silica Nanocomposites

There has been an increasing interest in the use of nano- sized fillers as additives to polymer materials (nanocomposite) because of its superior performance in dielectric strength. Although most power apparatus are operated at relatively high temperature due to power dissipation in themselves, few studies have investigated the influence of temperature on an electrical tree in nanocomposite polymer. Therefore, the effect of temperature on tree propagation and phase resolved partial discharge (PRPD) pattern in epoxy/silica nanocomposite are investigated. The results show that tree shapes in 0-wt% and 5-wt% samples change from branch-like to bush-like as temperature rises. On the other hand, tree shapes in 10-wt% samples keep bush-like regardless of the temperature. The maximum amplitude of partial discharge increases with the temperature. PRPD pattern when a tree starts to propagate forms wing-like one regardless of the amount of nano-particle and the temperature.