Performance Evaluation of Modulation Techniques in Single-Phase Dual Active Bridge Converters

Abstract

This research presents a thorough comparison of different modulation techniques employed in dual active bridge (DAB) converters. The performance of a DAB converter is essentially affected by the modulation technique and the operating point, including power level, input, and output voltages. A deep understanding of different modulations is required to achieve the highest performance in the entire operating range. Therefore, this paper focuses on comparing different modulation techniques over a DAB converter's operating span. The comparison results provide guidance to apply the correct modulation in certain working areas keeping the converter on top of its performance. Moreover, the paper proposes an optimization solution with distinct objective functions adoptable in DAB converters to reduce power loss. The proposed optimization approach outperforms the existing solutions regarding generality and simplicity. The optimization associates with the modulation techniques that include more than one degree of freedom, such as extended phase shift (EPS) and dual-phase shift (DPS). The proposed optimization and the investigated modulation techniques are evaluated in terms of the converter's efficiency, current stress, and backflow power. The evaluation is realized by the simulation study of a $10{\rm{\,kW}}$ $800{\rm{V}}/500{\rm{V}}$ SiC-based DAB converter in PLECS software.

Keywords

• Dual active bridge (DAB) converter
• efficiency
• modulation techniques
• backflow power
• current stress