Simulation on the Surface Charge Behaviors of Epoxy Insulator by Corona Discharge

A majority of the high voltage (HV) electrical equipment which has solid-gas insulation has suffered greatly from the accumulation of the surface charges gener-ated from the corona discharge. The local electric field may be distorted by the surface charge ’ s existence and in turn causes the surface flashover faults in excessive circumstances. Consequently, it ’ s significant to work out the mechanism of the procedure of the surface charge accumulation. A simulation model which combines both the charge trapping-detrapping procedure and the plasma hydrodynamics was created. The outcome of the simulation has agreed with the experimental results. The corona discharge intensity rises in the initial stage and then reduces as time goes by. There are various shapes of the surface potential distribution curves at various times. The central value increases quickly with time first and at last becomes saturated. Surface charges are observed in the epoxy insulator ’ s skin layer, some of them are mobile but some are captured by traps.