The essential characteristics of partial discharge can not be well described because of the simple traditional three-capacitor model of PD.Based on the plasma theory

not only the impedance-expression of the channel of partial discharge is presented

but also the new physical model of PD is constructed based on the capacitor-resistor-inductor parameters.The process of partial discharge of single and double voids in epoxy resin was simulated by Matlab/Simulink.The results show that the simulation of the model is very close to that of the experiment.It provides a new way for the more in-depth study of the mechanism of partial discharge.