Efficiency and reliability are essential for isolated bidirectional dc-dc converters in electric vehicle (EV) battery charging systems. As one promising power interface between energy storage components and power bus, dual-active-bridge (DAB) dc-dc converters have gained wide applications due to the advantages of galvanic isolation, symmetric circuit structure, high power density, and easy control implementation. In this article, based on the triple-phase shift (TPS) control, a fast and effective fault diagnosis strategy is proposed for DAB converters to improve both the power conversion efficiency and reliability. First, the operation principle of DAB converters with TPS control is presented. Then, a fast and effective open-circuit fault (OCF) analysis under different operation modes of TPS control is presented. Based on the resonant phenomenon during the fault conditions, an OCF diagnosis strategy that uses midpoint voltage as diagnosis criteria is proposed for DAB converters under the advanced TPS control to identify the faulty devices quickly and avoid the system collapse. After the failure switches are located, fault-tolerant operation is adopted to maintain the power transmission ability of DAB converters and ensure safe operation. The experimental results are provided to validate the correctness and effectiveness of the OCF performance analysis, fault diagnosis, and tolerant method.

中文翻译：

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用于双向电动汽车充电系统的具有三相移控制的双有源桥变换器的故障诊断和容错控制


效率和可靠性对于电动汽车 (EV) 电池充电系统中的隔离式双向 DC-DC 转换器至关重要。作为储能组件和电源总线之间一种有前途的电源接口，双有源桥（DAB）DC-DC转换器由于具有电流隔离、对称电路结构、高功率密度和易于控制实现的优点而获得了广泛的应用。本文基于三相移（TPS）控制，为DAB转换器提出了一种快速有效的故障诊断策略，以提高功率转换效率和可靠性。首先，介绍了采用 TPS 控制的 DAB 转换器的工作原理。然后，提出了TPS控制不同操作模式下的快速有效的开路故障（OCF）分析。基于故障条件下的谐振现象，针对先进TPS控制下的DAB转换器，提出了一种以中点电压作为诊断标准的OCF诊断策略，以快速识别故障器件并避免系统崩溃。定位故障开关后，采用容错运行，维持DAB转换器的电力传输能力，保证安全运行。实验结果验证了OCF性能分析、故障诊断和容错方法的正确性和有效性。