Back-flow Power Optimization Strategy of DAB Converter with Extended Phase Shift Control

The proposal of the double carbon policy requires ports in heavily polluted areas to achieve green transformation. Developing clean and renewable energy and researching green power supply technologies are the main measures to achieve carbon reduction in ports. The dual active bridge (DAB) DC-DC converter is an important component of DC microgrids, and the magnitude of its back-flow power determines the overall efficiency of the system. To address the issue of high back-flow power in traditional single phase shift (SPS) control, this paper investigates a minimum back-flow power optimization control strategy based on the extended phase shift (EPS) control. By utilizing the Karush Kuhn Tucker (KKT) algorithm, this control strategy can achieve segmented optimization of back-flow power within a wide power range. Then, simulation results verify the effectiveness of this optimization control strategy.