Simulation Research on Partial Discharge at Wedge-shaped Oil Gaps in Oil-paper Insulated under DC Stress

In order to study the characteristics and development process of partial discharge at the wedge-shaped oil gaps in oil-paper insulation system of converter transformers, in this paper, a simulation under DC voltage based on space charge models such as hydrodynamic drift-diffusion model and bipolar charge transport model was built. By analyzing the simulation results and characteristics of discharge, the discharge process of wedge-shaped oil gaps was divided into three stages.