DC Fault Diagnosis and Suppression Method of Dual Active Bridge Converters Based on Junction Temperature Reliability Feedback

Due to the bidirectional energy flow characteristic of the dual active bridge (DAB) converter, it is widely used in situations where electric energy needs to be transmitted back and forth, such as bidirectional energy transmission between electric vehicles and power grids. In order to improve the reliability and safety of the DAB converter, fast fault point detection and effective fault protection mechanism are crucial to improving circuit reliability. This paper proposes a fault detection and active thermal control strategy (ACT) based on junction temperature lifetime reliability feedback. It can detect whether the short circuit faults (SCFs) occurs in the secondary side silicon carbide (SiC) device by monitoring the junction temperature fluctuation of the primary side SiC device. The proposed ACT algorithm actively adjusts the circuit drive signal after the fault occurs to eliminate the fault in time. At the same time, it ensures effective fault monitoring without significantly sacrificing the lifetime of the primary side SiC devices.