Analysis of the Characteristics of Gas-Solid Insulation Surface Discharge under High Frequency Sinusoidal Electrical Stress and Construction of Simulation Model

Since surface discharge in gas-solid insulation is a common defect in high frequency transformer, it's of great significance for the application of high frequency power transformer to study the surface discharge phenomena and characteristics of gas-solid insulation under high frequency sinusoidal electrical stress. In this paper, the needle-plate electrode high frequency surface discharge experiment platform was built, and the constant pressure method was used to carry out the experiment. The development forms, characteristic parameters and spectra of discharge at different stages are obtained. For further research, a surface discharge simulation model is established. The experimental and simulation results show that the surface discharge of polyimide films under high frequency sinusoidal voltage develops from corona generation to streamer discharge to surface flashover. The surface discharge shows a strong polarity effect, and the number and amplitude of positive half-cycle discharge are both greater than negative half-cycle. The damage of the discharge process to the insulation surface leads to the electric field distortion, which affects the development of the discharge.