Insulation Lifetime Characteristics of Epoxy/TiO2 Nanocomposite with Internal Void

Polymer nanocomposite material, i.e., polymer insulating material with nano-sized inorganic additives, has recently received much attention for their superior dielectric performance as insulating media of high voltage power apparatus. The long-term insulation lifetime is one of the important factors, which determines the insulation reliability of the apparatus. In this research, the insulation lifetimes of epoxy/TiO2 nanocomposite and neat epoxy resin were experimentally investigated. The long-term experiments were carried out with a test electrode system with an artificial enclosed-void, which simulated air cavities contained within the insulation of the actual-scale apparatus. The time evolutions of partial discharge (PD) intensities were also recorded during the long-term experiment. Consequently, the epoxy/TiO2 nanocomposite showed more than 16 times longer lifetime compared to the neat epoxy resin. Finally, the superiority of the epoxy/TiO2 nanocomposite was discussed based on the PD energies.