Application of DAB Converter with Partial Power Transfer in Battery Energy Storage Systems

Battery energy storage systems play a pivotal role in the domains of renewable energy integration, electric vehicles, and grid management. In order to enhance transmission efficiency and mitigate current stress, a dual-active-bridge (DAB) converter with partial power transfer (PPT) is proposed. Within this PPT structure, an in-depth analysis of the DAB converter's efficiency is conducted on the system's overall transmission efficiency, taking into account variables such as voltage gain, DAB efficiency, and bidirectional flow. To improve efficiency even more, a dynamic zero voltage switching (ZVS) modulation scheme for the DAB converter is designed to allow for ZVS and optimal control of inductor current. This modulation scheme results in a reduction of losses and an improvement in system efficiency. Moreover, verify the structure and modulation scheme through a 480W/50kHz simulation model in Matlab/Simulink and theoretically analyze at 99.6% peak efficiency. Meanwhile, build a 120w experimental platform to verify the theoretical analysis. When the transmission efficiency of PPT converter is 87.5%, the system efficiency is 96.3%.When the transmission efficiency of PPT converter is 84.2%, the system efficiency is 93.4%, which verifies the validity of the theoretical analysis.