Electrical tree evolution of two-dimensional BN sheet composite epoxy resin with different particle size

The packaging insulation of power electronic devices works in high-frequency, high-voltage, and high-temperature environments, which suffers from electrical tree aging and seriously restricts the reliable operation of power electronic devices. In this paper, WZ breakdown model is used and the tree growing and fractal dimension characteristics with different sheets size are simulated. In addition, electrical tree initiation and growing characteristics of BN/epoxy resin composites are observed and studied under high-frequency voltage. Results show that with the increasing sheet size, tree initiation voltage increases first and then decreases. From the simulation and experimental results, after adding two-dimensional sheet, electrical tree tends to be more bifurcated, and as the sheet size increases, the growing rate decreases, the fractal dimension of tree increase correspondingly. It is believed that by introducing BN sheet into the matrix, the barrier effects and the forming deep trap both make electrical tree difficult to initiate and grow. The above researches could provide a solution to the regulation of electrical tree aging performance in the insulation layer of power electronic devices.