Effect of Trap Properties on the Surface Potential Decay of Oil-Impregnated Paper

Space charge accumulation and electric field distortion is one of the key problems to the electrical equipment under DC voltage. There are a large number of traps in oil-impregnated paper, which will capture free electrons and free holes and seriously threaten the insulation performance of converter transformer. Therefore, the study of space charge distribution is of great significance to improve insulation properties. This paper mainly studies of the effect of space charge distribution on surface potential attenuation. Based on the bipolar carrier model, a one-dimensional single-layer dielectric simulation model is established, and the simulation research is carried out from three aspects: charge injection depth, trap distribution and trap energy level. The results show that the charge injection depth mainly affects the space charge distribution by affecting the initial induced charge, and the trap distribution has a similar phenomenon with the trap energy level, which affects the space charge distribution by affecting the composite reaction between the space charge and the trap.