Active Gate Driver With Auxiliary Branch for Current Sharing of Paralleled SiC MOSFETs

In high-power applications, paralleling silicon carbide mosfets is commonly adopted to overcome the current limitation of a single device and achieve higher current capability. However, imbalanced dynamic currents during the switching process can lead to uneven power and thermal distribution, negatively affecting the overall stability of the system. This article presents an active gate driver (AGD) that features an auxiliary driving branch designed to improve current sharing among the mosfets. The proposed AGD only requires a single switch to achieve the conversion of driving modes, reducing the complexity of the control program. Moreover, the proposed AGD enables multilevel driving resistance adjustment by controlling the activation time of the auxiliary branch. Experimental validation confirms the efficacy of the proposed AGD. Test results indicate that the presented AGD enhances current sharing performance across diverse load conditions while improving current sharing in dc–ac conversion scenarios. In addition, in experiments involving multiple parallel devices, the proposed AGD demonstrates exceptional current sharing performance.