考虑寄生参数的隔离型双有源桥DC-DC变换器的开关开路故障分析与容错控制策略

双有源桥(DAB)DC-DC变换器开关管的驱动电路故障导致开关开路故障(OCSF),这使得DAB系统拓扑对称性缺失、高频电压和电流发生畸变和直流偏置,进而对系统的可靠性和长期运行稳定性造成不良影响.对此,研究DAB开关管和高频变压器寄生参数对OCSF后系统运行状态的影响,以完善DAB故障分析体系.针对OCSF问题,提出一种基于对称拓扑和对偶原理的故障容错策略,通过闭锁开关使系统运行拓扑恢复对称,并在此基础上提出一种不改变控制器参数、只需改变控制器输出饱和参数的实用控制方法,并在理论上讨论了该方法的可行性.最后,通过实验验证了OCSF模态分析及所提容错控制策略的正确性.

Open-circuit switching fault analysis and fault-tolerant control strategy for isolated dual active bridge DC-DC converter considering parasitic parameters

The OCSF(Open-Circuit Switching Fault) caused by driver circuit fault of DAB(Dual Active Bridge) DC-DC converter switching tube may cause system topological asymmetry, high-frequency voltage and current distortion and DC bias, which results in adverse effects on system reliability and long-time operation stability. Therefore, the influence of parasitic parameters of DAB switching tube and high-frequency transformer on the operation state of system after OCSF is studied, so as to improve the DAB fault analysis system. Aiming at OCSF problem, a fault-tolerant control strategy based on symmetric topology and duality principle is proposed, which restores the symmetry of system topology by blocking switch. On this basis, a practical control method is proposed, which only needs to change the controller output saturation parameters without changing the controller parameters, and its feasibility is discussed theoretically. Finally, the correctness of OCSF modal analysis and the proposed fault-tolerant control strategy is verified by experiments.