An SiC & Si Hybrid Five-Level Unidirectional Rectifier for Medium Voltage UPS Application

With the continuous advancement of wide bandgap devices and the development of multilevel technology, medium voltage high power active front ends (AFE) are becoming more and more attractive in many areas, especially in medium voltage UPS system for data center. In order to further improve the power density of the high power AFE and also keep the relatively low cost, a SiC & Si hybrid five-level unidirectional rectifier is proposed which requires only four SiC MOSFETs with relatively low blocking voltage. Meanwhile, all the Si devices are with low-speed switching. Firstly, the merits of the proposed rectifier are illustrated. Then, the circuit operational analysis is given. Finally, simulation and experimental results verify that the proposed rectifier is suitable for high power density medium voltage applications.