Asymmetric Fault-Tolerant Control of 3-Phase Coupled Buck–Boost Converter

A coupled inductor can optimize the weight of a DC/DC converter while the performance characteristics are complicated. To reduce the influence of system fault and keep the stable operation of the coupled converter, a fault-tolerant strategy is proposed. Firstly, a mathematic model is obtained to compare the difference between a coupled converter and a normal converter. Then, an open-circuit fault process is analyzed for fault detection. To design a proper fault-tolerant control system, transfer functions in asymmetric conditions are analyzed, and the operation of the mode switching is optimized for better a transition process. Finally, the method is verified by simulation and experiment.