A Fault-tolerant Scheme for Switching Devices in Current-Fed Dual-Active-Bridge Converter

Current-fed dual active bridge (CF-DAB) DC/DC converters have been widely used in renewable energy applications. The reliability of the CF-DAB converters attracts lots of attention. However, so far, the fault-tolerant schemes for switching device failures are mainly reported on three-phase CF-DAB converters, and limited literature focuses on the single-phase structure due to the low device redundancy. To address this important issue, a fault-tolerance scheme is proposed for the switching devices in the single-phase CF-DAB converter in this paper. With the proposed scheme, the CF-DAB converter can maintain the power transfer capability even if the two upper switching devices in the current-fed full bridge fail. Subsequently, this paper elaborates on the fault-tolerant converter characters and corresponding control strategies. Finally, the experimental results verify the performance of the proposed fault-tolerant scheme.