Comprehensive Analysis and Efficiency-Optimized Modulation of Resonant Dual Active Bridge DC-DC Converters with T-Type Impedance Network

The comprehensive analysis of resonant dual active bridge (RDAB) dc-dc converters with T-type impedance network is presented in this paper. Since the existing resonant tanks are special cases of T-type impedance network, a unified description of the performance characterization is reached for RDAB. On this basis, a topology construction principle of the RDAB is developed, which is expected to realize the full soft-switching as well as high power factor operation in the whole operating range. According to proposed construction principle, the T-type impedance network for CLLLC RDAB is construction. Furthermore, an efficiency-optimized modulation strategy is proposed, achieving full zero-voltage switching (ZVS) operation with large variations in port voltage, while reducing reactive power losses. Finally, the experimental results verify the outstanding performance of the proposed converter and optimized modulation strategy.