LLC resonant converters are widely applied in on-board power supplies owing to their high power densi-ty, high efficiency and small size, and their reliability is critical to the driving safety and passenger experiences. Howev-er, the complicated working conditions and harsh environment under which vehicles operate have become a huge chal-lenge to power devices. When a switch failure occurs, the resonant converter cannot maintain a stable output voltage while operating at a resonant point, and both efficiency and output capability of the system will decrease substantially. To make the converter more compatible with fault occasions, an improved LLC topology and its control strategy are pro-posed in this paper, which can ensure that the output voltage remains unaffected when a switch failure occurs and the converter operates near the resonant frequency. Additionally, an optimized Burst control strategy is designed to suppress the overvoltage of the resonant capacitor during the fault tolerance transition and guarantee a smooth fault tolerance pro-cess. Finally, simulation and experimental results verified the effectiveness of the proposed method.
维普
万方数据