A Novel Transistor Open-Circuit Fault Localization Scheme for Three-Phase Dual Active Bridge

Dual Active Bridge Isolated Bi-directional DC-DC Converter (DAB-IBDC) is suitable for a variety of important applications. In this paper, a new method is proposed to identify and localize transistor open-circuit fault (TOCF) for a three-phase DAB-IBDC. The operation of three-phase DAB-IBDC during TOCF is analyzed. Consequences and features of this failure have been investigated. Subsequently, a fault diagnosis scheme is proposed for this type of failure with the capability of locating the defected transistor using the polarity of transformer currents DC component. The main advantages of this scheme are minimum additional sensors and insensitivity to converter operational conditions. The transformer and its magnetic inductance is also considered in this method. Finally, simulation results are presented to evaluate the validity of analyses and performance of fault diagnosis method.