Third Quadrant Characteristic Model of Silicon Carbide MOSFET Considering Channel and Body-Diode Dynamics

A third quadrant characteristic (3rd-QC) model is proposed in this article, which accurately predicts the reverseconduction behaviors of the SiC MOSFET. The proposed model considers the floating substrate effect (FSE), interface state effect (ISE) and temperature sensitive effect (TSE) in detail, so the I-V trajectory from the source to the drain terminal could be efficiently evaluated. A dynamic test platform (DTP) is designed to extract the 3rd-QC data more comprehensive than that provided in datasheet, thus the proposed model works well in a wide operation range of the SiC MOSFET. The proposed model decouples the currents in the MOS path and body-diode path, making the current-sharing ratio clearly observable. In order to verify the accuracy of the proposed model, a dynamic validating platform (DVP) is implemented, and the complex converter is also simulated with the proposed model. The simulation results agree well with the experimental results, demonstrating the great potential of the proposed model in predicting the 3rd-QC behaviors of the SiC MOSFET.