Fault-tolerant DC-AC converter with split-wound coupled inductors

This paper presents a fault tolerant converter designed for low power applications, as required in a micro-grid environment. The main advantages of this converter when compared with solutions presented in the technical literature are: 1) higher number of levels using the same amount of controlled switching devices (six IGBTs), b) no dead-time requirement for the converter´s operation, which is an important aspect for high-frequency micro-grid systems and c) leg isolation procedure with reduced stress for the dc-link capacitor. Furthermore, this paper presents a hybrid pulse-width-modulation for the pre-fault operation. Details regarding the transition from the pre-fault to post-fault operation is presented. Selected steady-state and transient results are presented to validate the theoretical expectations.