应用于高频辅助变流器的DBSRC变换器IGBT开路故障分析及容错运行研究

IGBT open-circuit fault analysis and fault-tolerant operation research of DBSRC converter applied to high-frequency auxiliary converter

随着电力电子技术的进步,以双向全桥串联谐振变换器(dual bridge series resonant DC-DC converter,DBSRC)为核心的新一代高频车载辅助变流器发展迅速,并逐步走向实用化。为了提高基于DBSRC变换器的高频辅助变流器的可靠性,首先利用模态分析法(operation mode analysis,OMA)对移相闭环控制下DBSRC发生IGBT开路故障展开研究,分析并阐明了DBSRC输入、输出侧故障后的运行机理及特性。其次,提出一种基于输出功率调整的高频车载辅助变流器容错运行策略,在不改变DBSRC拓扑及移相控制方法的条件下通过实时监测辅助变流器输入电压并动态调节辅助变流器的输出功率,将谐振电流应力及谐振电容电压应力限制在安全阈值内,实现容错运行。最后通过仿真与实验对故障特性分析的准确性与该容错运行策略的有效性进行验证。

With the advancement of power electronics technology,the new generation of high-frequency vehicle auxiliary converters with dual bridge series resonant DC-DC converter(DBSRC)as the core have developed rapidly and are gradually moving towards practicality.In order to improve the reliability of high-frequency auxiliary converter based on DBSRC,using operation mode analysis(OMA)to study the IGBT open circuit fault in DBSRC under phase-shifting closed-loop control first,the operating mechanism and characteristics of DBSRC after input and output side faults are analyzed and clarified.Second,a fault-tolerant operation strategy based on output power adjustment for high-frequency auxiliary converter is proposed for DBSRC IGBT open-circuit fault.It real-time monitors the input voltage of the auxiliary converter,and dynamically adjusts the output power,limiting the resonant current stress and resonant capacitor voltage stress to a safe threshold and achieving fault-tolerant operation,in the context that DBSRC topology and phase-shifting control method are retained.Finally,the simulation and experimental results verify the accuracy of the fault characterization and the effectiveness of the fault-tolerant operation strategy.