A Novel Fault-Tolerant Dual Active Bridge Converter Operation for Electric Vehicle Chargers

The Dual Active Bridge (DAB) DC-DC converter, characterized by its capability to facilitate bidirectional power flow and provide galvanic isolation, is notably employed in several applications. Failure in power electronic devices of the DAB can cause power flow disruption, which may affect the charging station, reduce system performance, affect battery life, and overall reliability of the application. The existing DAB fault-tolerant methods do not successfully solve the simultaneous double switch failure on one side. This paper introduces a fault-tolerant methodology designed to mitigate Open-Circuit Faults (OCFs) in the active devices of the DAB converter, applicable for both single switch and multiple switch failures. The fault-tolerant approach involves the redundant switch, parallel connection of a resonant capacitor, and a Single Pole Single Throw (SPST) electromagnetic relay, collectively termed as a fault-tolerant mechanism, with both the primary side and secondary sides of the transformer. Once the OCF is detected, the incorporated redundant switch or fault-tolerant capacitor is connected to ensure the reliability of the system. The simulation outcomes of the proposed topology have been successfully attained on MATLAB Simulink® for a 2 kW, 240 V rating.