Ui-Min Choi, Kyo-Beum Lee, and Frede Blaabjerg, “Diagnosis and Tolerant Strategy of an Open-Switch Fault for T-Type Three-Level Inverter Systems,” IEEE Transactions on Industry Applications, vol. 50, no. 1, pp. 495–508, Jan./Feb. 2014. -SCI > Paper

This paper proposes a new diagnosis method of an open-switch fault and fault-tolerant control strategy for T-type three-level inverter

systems. The location of the faulty switch can be identified by the average of the normalized phase current and the change of the

neutral-point voltage. The proposed faulttolerant strategy is explained by dividing into two cases: the faulty condition of half-bridge

switches and neutral-point switches. The performance of the T-type inverter system improves considerably by the proposed fault-

tolerant algorithm when a switch fails. The proposed method does not require additional components and complex calculations.

Simulation and experimental results verify the feasibility of the proposed fault diagnosis and fault-tolerant control strategy.