Fault-Tolerant Active Neutral-Point-Clamped Multilevel Inverter Maintaining Output Voltage at Failure.

For safety-critical application, fault-tolerant operation capability under the condition of switching device fault is getting significantly important. The proposed circuit is a combination of three phase Active Neutral Point Clamped (ANPC) multilevel invert and T-type multilevel inverter. In this circuit, the rated output voltage is maintained in cases of both open-circuit switching fault and short-circuit switching fault. Also, switching devices are reduced compared to conventional circuits. In this paper, utility of the proposed circuit is verified by simulation and circuit experiment.