A Load Adaptive DPS Control for DAB with Reduced Current Stress for Wide Load and Voltage Range

This paper presents a load adaptive DPS control for a dual active bridge (DAB) DC-DC converter. The control is effective for DAB used for charging of EVs (Electric Vehicles) with pre, CC (Constant Current) and CV (Constant Voltage) charging modes. The DPS (Dual-Phase-Shift) control provides an efficient selection of phase shift ratio, which reduces the switch current stress and improves the power transfer efficiency during both pre and CC charging mode. During CV charging mode, DPS control with the bidirectional inner phase shift control is used to improve control range of outer phase shift ratio at low loading condition. A method for the selection of both phase shifts, is presented in order to minimize peak inductor current at different voltage conversion ratio faced by DAB during whole charging range. A 10kW DAB DC-DC converter is designed and its control is validated through MATLAB/Simulink results. A set of results at different charging voltage and charging rates are presented with steady state and dynamic performances.