Simulation of partial discharge of oil-paper insulation under high-frequency electric field

Partial discharge in oil-immersed transformer is often an important inducement for equipment failure. The research on partial discharge of oil-paper insulation of oil-immersed transformer is mainly based on DC and power frequency AC conditions, there are few researches on partial discharge of gas-solid insulation system at high frequency, focusing on the influence of voltage form, temperature and other factors on the macro characteristics of discharge. In this paper, a high-frequency partial discharge simulation model considering the transition zone of oil-paper insulation interface is adopted, the characteristic changes of partial discharge of oil-paper insulation at different high frequencies are simulated, it includes initial partial discharge voltage, electron charge density and ion recombination, the residual charge and partial discharge amplitude in the transition region are compared under DC voltage and power frequency AC voltage. The results show that: the initial voltage of partial discharge at high frequency gradually decreases with the increase of frequency, under the action of strong electric field, ion recombination will occur; the amplitude of partial discharge at power frequency is much lower than that at high frequency, which is due to the influence of voltage rise rate and surface charge relaxation characteristics; in addition, the residual charge in the transition region at high frequency is significantly higher than that of DC, and the dissipation amplitude is also much larger than that of DC. Provide simulation basis for insulation coordination optimization of composite oil-paper insulation system under high frequency voltage.