Device-Sharing-Based Bidirectional DC-DC Converter with Wide Voltage Regulation and Enhanced Fault Tolerance

In response to the evolving requirements for wide voltage range and high reliability in electric vehicle (EV) high-voltage traction bus architectures, this paper proposes an isolated bidirectional DC-DC converter based on a devicere-use methodology. The topology can achieve wide voltage regulation under a low transformer turns ratio via a power-path reuse mechanism. Furthermore, by employing switching state reconfiguration, the converter maintains stable power output even under partial power device failures, significantly enhancing system fault tolerance. This paper provides an indepth analysis of the circuit characteristics of the converter under both steady-state and three typical fault conditions. To prevent performance degradation during faults, an optimized modulation scheme aimed at extending the soft-switching range and reducing the current stress. is proposed. Finally, an experimental prototype validates the theoretical analysis and demonstrates the superior performance of the converter under both wide‑gain range conditions and fault conditions.