一种单相电流型双有源桥DC/DC变换器的开路故障容错方案

Power interruptions are intolerable in many industrial applications, so high reliability becomes exceedingly pivotal to power converters. Fault-tolerant schemes attract more attention as an effective approach to improve reliability. However, due to the low-device-redundancy and asymmetrical structure, fault-tolerant schemes have not yet been reported on the single-phase current-fed dual-active-bridge (CF-DAB) converters. To address this challenging issue, an open-circuit fault-tolerant scheme is proposed in this article. With the proposed fault-tolerant scheme, the single-phase CF-DAB converter can maintain power delivery even if facing the open-circuit faults of two specific switches and the middle capacitor. Meanwhile, potential voltage spikes can also be suppressed effectively without the snubber function of the middle capacitor, which protects the switching devices from high-voltage stresses. Subsequently, the modulation scheme, mode characters, and control structure are elaborated. Finally, the experimental results based on a scale-down laboratory prototype are presented to verify the feasibility of the proposed fault-tolerant scheme.