Enhancing Resilience of DAB Converters with Fault-Tolerant Approach

The paper examines the dual active bridge (DAB) converter, highlighting its advantages such as adaptable control dimensions, reliable current isolation, high power density, and soft switching capability. Despite these advantages, the DAB converter has vulnerabilities such as stress on capacitors, semiconductor switches, and diodes, making them susceptible to short circuit faults (SCFs) and open-circuit faults (OCFs). SCFs are relatively easier to diagnose and locate but can cause substantial damage if not immediately isolated. In contrast, OCFs are harder to identify and can lead to system shutdowns due to voltage and current distortions. To tackle these issues, the paper analyzes the behavior of the system under eight different faulty switching actions and proposes a specialized fault diagnosis algorithm to avoid false detections. A proactive fault management strategy is proposed to reduce current stress and backflow power under faulty conditions, enhancing the system's resilience. To demonstrate the practicality of the proposed fault-tolerant control strategy, the paper also includes a real-time faulty situation as a case study.