Study on three-dimensional structural analysis method for electrical tree

The three-dimensional structure of branch type and bush type electrical trees were analyzed by using the X-ray computed tomography with the spatial resolution of 1.5 micrometer/voxel. The sliced images were reconstructed and treated by the computer software to calculate the fractal dimension of electrical tree. The three-dimensional structure obtained from X-ray computed tomography experiment was compared with the structure calculated by the dielectric breakdown model. It became clear that the three-dimensional fractal dimension of branch type electrical tree in the unfilled epoxy resin is 2.4 and bush type electrical tree in silica filled epoxy resin is larger than 2.4.