Three-Level NPC Dual-Buck Inverter Designed to Safety-Critical Applications

This paper presents a three-phase three-level NPC (neutral point-clamped) Dual-Buck inverter topology suitable to increase fault-tolerant capability to safety-critical applications. Using the proposed topology, it is possible to achieve energy processing capability in case of several failure modes. The fault-tolerant enhancements are a consequence of appropriate modifications in the control strategy and from redundancy of power devices to maintain the correct operation of the converter. The proposed control strategy adopted in the presented solution can also equalize the capacitor voltages automatically. Some simulation results are included in this study to confirm the validity of the theoretical study.