Hybrid Dynamic Voltage Balancing Technique for Series-Connected SiC MOSFETs

It is an effective way to achieve higher-voltage switches by series connection of individual semiconductors. However, the unequal dynamic voltage sharing is the main problem needs to be solved, especially for the wide band gap devices with quite high switching speed. This problem can be solved by using active gate control techniques, snubber circuits and active clamping circuits. In this paper, a hybrid method is proposed for balancing the dynamic voltages among series-connected SiC MOSFETs with both an active voltage clamp circuit and an optimized passive snubber. Circuit and parameter design of the driver will be proposed and experimental results will be given to verify the performance of the proposed circuit.