A Drive Circuit for Series-Connected SiC MOSFETs Based on Magnetic Constraint

Under the application of high voltage, both the single power device and module device need being connected in series to enhance the blocking voltage. For the series connected devices, the slight voltage mismatch will result in high power loss and even damage to the devices under the condition of high frequency and high voltage. The synchronization of the driving voltage is a prerequisite for ensuring dynamic voltage balance. This paper proposes a drive circuit for SiC MOSFETs in series connection based on magnetic constraint to make sure drive voltage synchronization. Only one standard gate driver applied on the primary side of the transformer, that provides effective electric isolation. The operation principles of the proposed topology are analyzed during the turn-on and off transition. At the end, the simulation results and experimental waveforms are shown to verify the feasibility of the driver circuit for SiC MOSFETs in series connection.