Research and Application of Hybrid ANPC Control Strategy

Active neutral point clamp (ANPC) is a three-level circuit suitable for high power. Using SiC MOSFET instead of part of Si IGBT to construct hybrid ANPC circuit can reduce loss and improve the efficiency of converter. This paper proposes a control strategy suitable for hybrid ANPC circuits. By concentrating switching actions on SiC devices, Si devices only need to bear the conduction loss, making full use of the advantages of low switching losses of SiC devices and low cost of Si devices. Firstly, working principle of the proposed control strategy is analyzed, and then a 3kW single-phase ANPC converter prototype is built. Comparing device temperatures when using different control strategies. It is proved that the proposed control scheme is more suitable for the hybrid ANPC circuit. Finally, the proposed control strategy is used to compare the efficiency of all SiC devices, all Si devices and hybrid converters. Experimental results show that this control strategy can achieve high efficiency while keeping low cost of hybrid ANPC converter.