A novel active T-type three-level converter with open-circuit fault-tolerant control

This paper proposes a novel active T-type three-level converter concept with fault-tolerant control. With the proposed topology, the converter can be operated continuously under open-circuit faults. It is shown that the proposed topology not only can keep its outputs under open-circuit fault condition without degradation of performance but can also reduce the thermal stresses in neutral-point power devices by redundant current path. The junction temperature reduction in the neutral-point devices could improve the lifetime of the system under some operating conditions especially when the neutral-point devices have the highest thermal stresses. The feasibility and effectiveness of the proposed topology concept are verified by the simulation results.