An Advanced Fault-Tolerant HANPC Converter With Neutral-Point Voltage Balancing for Full Power Factor Range Under Multi-Switch Open-Circuit Fault

Hybrid active neutral-point-clamped (HANPC) converters are receiving more attentions owing to considerable cost-effectiveness and high efficiency. However, when open-circuit fault occurs in multiple switches, the existing fault-tolerant schemes cannot support the HANPC converter to operate at rated output voltage and satisfactory neutral-point voltage balancing. To address this issue, an advanced fault-tolerant HANPC (FT-HANPC) converter is proposed, which is equipped with shared fault management unit (SFMU) and voltage ripple suppression unit (VRSU). The proposed discontinuous space vector modulation strategy enables SFMU to take over the multiple faulty switches with minimal redundant active switches. Moreover, the VRSU with proposed control strategy is activated to effectively regulate neutral-point voltage for full power factor range under fault condition. The operation principle and fault-tolerant control of proposed topology are elaborated, respectively. Experimental results are presented to validate the effectiveness of the proposed topology.