Comprehensive analysis and design optimization of the Dual Active Bridge DC-DC converter with finite magnetizing inductance

This research provides an in-depth general analysis of a Dual Active Bridge (DAB) DC-DC converter with a finite magnetizing inductance (L
m
). A high-frequency transformer considered in this study is a radial-type rotary transformer for aerospace applications. A single-phase-shift (SPS) modulation technique is considered in this study. First, it develops new analytical equations for the RMS currents of the converter that include the effects of L
m
. The analysis is based on the equivalent T-type electric circuit transformer model. Then, this study shows that a high L
m
is not the best choice for the overall system performance, including loss and transformer mass, which have a direct effect on the converter's power density. The analysis further shows the effects of different system parameters such as the control phase-shift angle, transformer inductances, turns ratio, and switching frequency on the SPS-DAB performance. Understanding the impact of these parameters on the performance of the DAB can contribute to the optimum design of the converter. The proposed theory and analytical equations are validated by the MATLAB/Simulink simulation of a 40 kW 800V/800V DAB converter switching model.