This paper focuses on the typical fault of the series resonant dual-active-bridge (SRDAB) converters which are widely used in active DC distribution systems. Firstly
two fault tolerant control methods including duty-cycle regulation and topology reconfiguration of full-bridge converter
are analyzed and detailed compared on their characteristics and inherent drawbacks. Based on these analyses
a control method of hybrid fault tolerant is proposed. In this method
the output voltage is real-time monitored and can be recovered quickly through duty-cycle regulation if voltage sag appears. Secondly
the circuit automatically reconfigures to realize highly efficient operation if open-circuit fault is identified. By implementing this proposed method
the system acquires self-fault-diagnosis and self-recovery capabilities. Comparing to conventional fault tolerant methods that employ massive hardware redundancy and complex fault detection circuit to identify particular faults
this hybrid control method can realize highly efficient and reliable fault tolerant operation without any additional hardware. Thirdly
the proposed method has favorable transient and steady-state performances
and prevents defects of conventional methods such as current surge and voltage sag appearing when operation mode changes. Finally
experimental results are provided to validate the effectiveness of the proposed method on fault tolerant control for dual-active-bridge interfacing converters.