To address the challenges of low line impedance

excessive current peaks

and long recovery time under short-circuit conditions in dual active bridge (DAB) converters

this paper proposes a novel hybrid current-limiting device integrating coupled inductors a high-frequency chopper circuit. First

a transient mathematical model of the DC system incorporating the proposed current-limiting device is derived

and the current-limiting principle is explained. The impacts of critical parameters such as resistance

inductance

and transformer turns ratio on the current-limiting performance are systematically analyzed. Subsequently

a voltage derivative criterion is developed for rapid fault detection

while permanent/transient fault discrimination is achieved through continuous monitoring of the DAB output voltage

enabling coordinated operation with DC circuit breakers for precise interruption. Finally

comprehensive simulations are conducted on an input series output parallel-dual active bridge (ISOP-DAB) DC system under transient and permanent faults as well as pole-to-pole/pole-to-ground short-circuit faults. The simulation results demonstrate that

compared with conventional current limiters

the proposed solution reduces the short-circuit current peak by over 85% and shortens the fault isolation time by more than 40%

exhibiting superior performance in fault current suppression and system recovery acceleration.