The gate driver is the guarantee for the high efficiency of SiC MOSFET converter. Previous research showed that the switching loss of SiC MOSFET with current source driver (CSD) is lower than that with voltage source driver (VSD). But when the charging current of CSD is small or the Miller platform voltage is low, the switching loss of SiC MOSFET with CSD is higher than that with VSD. Therefore, this paper constructs an evaluation index K, which is the ratio of the current injected into the gate of SiC MOSFET during the Miller platform stage between VSD and CSD, to compare the switching loss between SiC MOSFETs with CSD and VSD under different conditions. When the load is determined, K depends on the selection of the charging current of CSD and the gate resistance of VSD. The mathematical model is verified by 600V/40A double pulse test (DPT) simulation and experiment. In actual situations, when VSD drive resistance is determined, the model can be used to calculate the critical CSD charging current value that makes the switching loss of SiC MOSFET with CSD lower than that with VSD.

Gate Driver,SiC MOSFET,switching loss,modeling