Optimizing inductance for minimizing reactive power in single-phase-shift modulated dual active bridge converters under variable input voltage

This paper proposes an optimal series inductance to minimize reactive power and conduction losses in the single-phase-shift modulation of a dual-active-bridge (DAB) converter. Considerable variations in the root mean square (RMS) current of the DAB converter occur due to changes in input voltages. This study visually analyzes the multivariate variation of RMS current in three-dimensional space, considering inductance and input voltage conditions. Additionally, the series inductance is optimized to ensure consistent performance under varying input voltages, using the coefficient of variation. Analytical examination and validation of RMS current changes with respect to series inductance under different input voltage conditions are conducted using a prototype 48 V–12 V DAB converter. Based on this analysis, an appropriate series inductance for optimizing performance is proposed.