In order to further understand the mechanism of partial discharge and discharge characteristics

it is necessary to simulate the partial discharge effectively. To solve the problems existing in original simulation models of which the influence of dielectrics on discharge process is neglected

firstly

by understanding experimental characteristics and physical processes of partial discharge

we calculated discharge delay time under the different polarity conditions according to charge attenuation in the air gap.Secondly

the conditions of inception and extinguishment of partial discharges were confirmed by calculation. Finally

the influences of temperature and pressure in void on the discharge characteristics was introduced

and the simulation model of insulation material with single void was put forward

which contained the additional capacitance that caused by induced charge during partial discharges. The simulation results obtained from MATLAB/SIMULINK show that

when the polarity of the voltage is constant

the air gap at both ends of the voltage of which waveform is a polarity change has a smaller discharge delay time

and the discharge pulse current is in small amplitude compared with the polarity changes. The model proposed in this paper can conform well to the theory of partial discharge

and simulate partial discharges effectively.