Design and simulation of low-ripple dual active bridge DC-DC converter

In addressing the issue of excessive high-frequency current ripple at the output port caused by high-frequency switching in traditional dual active bridge DC-DC converters, a low-ripple dual active bridge DC-DC converter was designed by replacing its switching devices with a half-bridge submodule. This converter constructs a decoupling loop for alternating and direct current components on the bridge arms, allowing the alternating components to form a loop between the bridge arms without entering the direct current port, thereby eliminating high-frequency current ripple at the direct current output port. Consequently, the filtering capacitors parallel to the direct current port can be omitted, while also suppressing direct current fault currents. Due to the inherent capacitance structure of the submodule switching devices, soft-switching characteristics are preserved, and conversion efficiency is not compromised. Simulation results based on a MATLAB/Simulink model of 750 V and 10 kW demonstrate that the ripple of this converter is less than 0.07%, a 90% reduction compared to traditional converters, and effectively suppresses fault currents, thereby enhancing system safety.