Piecewise Linear Approximation Minimum Current Trajectory for Dual Active Full-bridge Bidirectional DC-DC Converter

This paper will introduce a controller based on the piecewise linear approximation minimum current trajectory(PWL-MCT) for the series resonant dual active-bridge(SR-DAB) dc-dc converters based on the minimum current trajectory(MCT). The linear approximation is based on the minimum current trajectory, thus it can maintain an approximately optimized switching loss at full working range. The power flow through the Dual active-bridge DC-DC converter is controlled by adjusting the duty factor for both primary side and secondary side of the converter and the phase shifting angle between each side s voltage signal simultaneously. While applying the proposed controller, the tank rms current optimizing effect of this converter was proved to perform closely enough to the one applied with original minimum current trajectory controller.