Research on Multiple Duty Modulation Scheme in Dual-Active-Bridge-Based Energy Storage System

To ensure an efficient energy charging process inside the energy storage system, a dual-active-bridge (DAB) becomes a significant interface circuit because of its bidirectional power transmission ability and simple modulation scheme. In order to achieve DAB efficiency promotion, lower root-mean-square (rms) current stress and wider soft-switching region are required. Therefore, a multiple-duty modulation (MDM) is proposed to achieve the aforementioned goals. In this article, detailed derivations of mathematical models for typical MDM modes are demonstrated. Power characteristics and soft-switching performance are also depicted in detail. RMS current is selected as the optimization objective which is implemented by the fmincon function in MATLAB. To substantiate the effectiveness of the proposed modulation scheme, a comprehensive comparison among existing works in terms of rms current and soft-switching region are implemented under different conditions. Finally, a DAB-based experimental prototype is built and effectiveness under the proposed modulation scheme is verified.