Simulation of volatge-maintaining performance of high energy density capacitors based on the measurement of charging current

When a high energy density (HED) capacitor is charged to a certain voltage, the voltage of the capacitor will decay gradually. In this paper, an extended Debye model of relaxation polarization is established and the parameters of the model are obtained by analysis of polarization current. The simulation of the voltage decay of HED capacitors under different field strength, temperature and charging time is conducted, which can match well with the results of the measured voltage decay. And the results indicate that increases of temperature or field strength result in great increases of the voltage decay by altering the parameters of the extended Debye model. Nevertheless, charging time has no impact on these parameters, it affects the voltage decay by affecting the charges absorbed from the power supply by relaxation polarization branches of the capacitor.