Fault Ride-through Method for Dual-bridge Series Resonant Converter

The output-short-circuit (OSC) fault is a severe challenge faced by the dual-bridge series resonant converter (DBSRC). However, due to the uncertain state of the resonant cavity at the moment when the fault occurs, and the existence of residual energy that cannot be precisely controlled after current limiting, the initial state of the DBSRC during restart is uncontrollable, which will affect the working state of the DBSRC after restarting. This paper provides a fault ride-through method targeting the OSC fault in DBSRC. This method consists of four steps to achieve the detection, current limiting, location and clearance of the fault. Furthermore, the initial energy of the resonant cavity after current limiting and its influence on the fault ride-through process were quantitatively evaluated. A soft-start method has also been developed to determine the optimal phase-shift angle during fault localization. This approach can quickly restart the circuit within preset current threshold to establish fault criterion current. Finally, the simulation results demonstrate the efficacy of the proposed fault ride-through method.