Driving Strategy Optimization of a “SiC+Si” Hybrid Switch for Switching Loss Reduction

Si IGBT is popular for the excellent performance of current capacity. Nevertheless, its slow switching speed, as well as tail current, leads to elevated switching losses. In contrast, SiC MOSFET is well known for its excellent switching characteristics. To enhance the performance of power electronic converters, a parallel connection of Si IGBT and SiC MOSFET is introduced in this paper. The current distribution under different load current is studied. The power losses of different switching strategies and switching time delay are measured. To reduce power loss and improve the efficiency of the paralleled hybrid switch based converter, an optimized switching strategy is also proposed and proved by a double pulse test. On the basis of experimental results, we can see that the optimal switching delay time helps reduce turn-on loss by about 73% and turn-off loss by about 61.4% compared with the solely Si IGBT.