Multi-Objective Optimization Method Based on Double-Side Asymmetrical Modulation Scheme for DAB-Based DC-DC Converter

Due to its high power density, bidirectional power transmission capability, and simple modulation scheme, dual active bridge (DAB) converter has garnered increasing attention from researchers. However, conventional modulation methods often face controversies between current optimization and zero-voltage switching (ZVS) range optimization. To ensure efficient power transmission within the DAB converter, a double-side asymmetrical modulation scheme (DAMS) is proposed. This approach addresses the ZVS condition for each switch comprehensively, considering factors such as minimum ZVS current calculation, detailed analysis of the resonance process, setting of dead time (t
d
), and the non-linear variation principle of the junction capacitor (Coss). Furthermore, under the ZVS condition for all switches, a wide power-range multi-objective optimization using the non-dominated sorting genetic algorithm III (NSGA-III) is introduced to simultaneously optimize RMS current and peak current. This approach aims to overcome the narrow ZVS range issue associated with current optimization. Consequently, compared to existing modulation schemes, the DAMS proposed in this paper achieves the lowest RMS current and the widest ZVS range. Finally, a DAB-based prototype is established to validate the effectiveness and correctness of the proposed method.