Continuity of service of five-level H-bridge T-type converter under open-circuit switch failure

In this paper, an H-Bridge T-type converter with fault-tolerant capability under open-circuit switch failure is presented. An optimised and fault tolerant PWM control is applied to the converter, associated to a fault diagnosis block that allows detecting and localizing the open-circuit switch failure. A redundant leg with two bi-directional switches is used for fault-tolerant strategy and reconfiguration, after a fault occurrence diagnosis. Therefore, the converter can operate without performances degradation in post-fault operation. Some simulations are performed to validate the proposed fault diagnosis and the associated fault tolerant strategy.