Turn-off Period Improved Switching Model of SiC Devices with Stray Capacitances and Inductances

摘要

In order to analyze the switching behavior of SiC devices, this paper presents an improved switching model which considered the parasitic inductance, the nonlinear capacitances and the nonlinear transfer characteristic of SiC devices. Besides, this paper presents a new sub-period during turn-off transient when current is small. The proposed model is expressed by differential equations and the result can be obtained by iterative solution. The experiment is carried out based SiC bare dies at 400V DC voltage, 10A and 40A current. The result shows that the improved model matches the experiment better than the referenced model. At 40A condition, the relative error of turnoff losses are decreased by 53.8%, and the relative error of turn-on losses are decreased by 15.6% by using the proposed model. At 10A condition, the relative error of turn-off losses is decreased by 67%.