Study on Charge Trapping Processes of Epoxy Resin Nanocomposites

Space charge transport characteristics of epoxy resin composites under UHVDC play an important role in reliable performance of UHVDC dry casing and long term safe and stable operation of UHVDC transmission projects. In this paper, one-dimensional bipolar carrier transport model is established to numerically calculate the space charge distribution in epoxy resin composites. The effect of carrier mobility, trap depth and trap density on the internal space charge transport characteristics is investigated. Results show that with the increase of shallow trap distance, the carrier mobility increase which result in charge accumulation inside the samples and more serious electric field distortion. As deep trap depth and density increase, the charge accumulation area gradually moves from the center to both electrodes, effectively inhibiting the space charge injection and reducing electric field distortion. These results provide theoretical basis for reducing space charge accumulation in epoxy resin composites and optimizing structure of UHVDC dry casing.