Effects of Filler-size on Electrical Treeing in Epoxy/Silica Nanocomposites

There has been an increasing interest in the use of nanosized fillers as additives to polymer materials (nanocomposite) because of its superior performance in dielectric strength. It is known that nano-particle size may affect tree-propagation. In order to develop reasonable nanocomposite polymer which has larger particle diameter and smaller amount of nano-particles, the effect of filler-size on tree-propagation and phase resolved partial discharge (PRPD) pattern in epoxy/silica nanocomposite were investigated. The tree shape tends to become bush-like when the filler-size smaller, the amount of the nano-particle is larger, and the peak value of the voltage is lower. A PRPD pattern is determined by the tree shape regardless of the filler-size, the amount of the nano-particle and the peak value of the voltage.