Flashover property of epoxy resin and epoxy composites under fast pulse in transformer oil

Abstract

The flashover characters under nanosecond pulsed voltage in transformer oil of epoxy resin and epoxy composites are reported. It is indicated that the flashover voltage of epoxy resin decreases while flashover times increase, and the surface damage and impurities caused by multiple flashovers are considered to be the reason. The movement of bubbles is restricted when liquid pressure increases, so the flashover voltage increases evidently. The relationship between pulse steepness and the flashover voltage is fit and extrapolated, and the fit result based on the reciprocal form of Schottky effect equation is preferable. In addition, the research of Micro TiO 2/epoxy composite samples with different filler weight percent demonstrates that while the weight percent of TiO 2 increases the flashover voltage varies as a 'V' style, and the lowest voltage value is obtained when the filler weight gets about 20%.