The Research On Current Dual Active Bridge Bidirectional DC-DC Converter

At present, the bidirectional DC converter is widely used in many fields. However, for the voltage dual active bridge bidirectional DC-DC converter, the leakage inductance current slew rate cannot be kept zero during the power transfer stage. And for the current fed dual active bridge bidirectional DC-DC converter with the conventional PPS control, the large peak current of the leakage inductance and the large circulating current will make the efficiency decrease. Further, the soft switch cannot be achieved during the full load range.In view of the above problems, a double PWM plus double phase shifted(DPDPS)control is proposed for current-fed dual-active bridge(DAB)bidirectional DC-DC converters.With which, the peak current of the leakage inductance, the circulating current during the non-power transfer stage can be minimized, and the converter has the higher efficiency and higher reliability.In this thesis, the mode analysis of the current-fed bidirectional DC-DC converter using the proposed control strategy is given. The relationship between the power and the duty ratio and phase shift angle, the current stress of the DC inductance and leakage inductance, the voltage and current stress of the MOSFET, and the soft switching conditions are analyzed.Further, the prototype is designed, whose key parameters, incuding the DC inductor, the AC inductor, and the transformer, are fully analyzed. Then the small signal modeling and the simulation are made as well.Last, the prototype is built to verify the proposed topology employing the proposed DPDPS control.