A Passive Component Based Gate Drive Scheme for Negative Gate Voltage Spike Mitigation in a SiC-Based Dual-Active Bridge

This paper introduces a simple and reliable gate drive scheme which could effectively solve the negative voltage undershoot at the gate terminal of SiC device during the turnoff process of the Dual-Active Bridge (DAB) topology. Through inserting a diode and a magnetic bead into the classic gate drive circuit, the drive scheme could be formed. The operating principles of the proposed drive scheme could be divided into four stages and described in details, in consideration of the complementary switch in the phase-leg as well as the diode in the gate drive circuit. The effectiveness of the proposed gate drive circuit could be validated on a SiC-based double pulse tester under the working condition of DAB. The main contribution of this work is that the proposed scheme would largely improve the capability of the passive gate driver on the mitigation of the negative gate spike. Based on the simple structure and passive component's reliable performance, the proposed gate drive scheme could be directly adopted to DAB. The design guideline is also proposed, where the gate voltage spike could be controlled through the adjustment of magnetic bead's impedance.