Investigation on the Transient Performance Improvement of Dual-Active-Bridge Converters Based on Optimal Current Stress Control

Dual-active-bridge (DAB) converters are widely used in DC microgrids, electric vehicle charging, and other fields due to the excellent performance in bidirectional power transmission. In recent years, the transient performance improvement and steady-state optimization strategies of DAB have been widely discussed and studied. In terms of steady-state optimization, optimal control strategies targeting different optimization obj ectives have been proposed. In terms of transient performance improvement, there are already many effective control strategies for DAB converters under single-phase-shift (SPS) control. However, for the optimal current stress (OCS) control, there are still few corresponding transient performance improvement strategies to coordinate with it. Aiming at improving transient performance, this paper first investigates the impact of PI parameters on the DAB converter under SPS control and provides a reference for PI parameter adjustment based on the conclusion. For optimal current stress control based on triple-phase-shift (TPS) control with complex transient processes, virtual resistance feedforward (VRF) control is proposed to improve the transient performance of the DAB converter. Finally, the correctness of the analysis conclusion and the effectiveness of the proposed VRF control are verified via MATLAB/Simulink.