Fast transient current control for three-phase dual-active-bridge dc-dc converters with variable duty cycles

摘要

This paper proposes two fast transient current control (FTCC) methods for three-phase dual-active-bridge (3p-DAB) dc-dc converters under PWM control strategy with three control variables. The proposed control methods can balance three phase inductor currents fast and avoid the oscillations in dc currents when duty cycles are changed abruptly caused by fast changed transmission power. The space-vector method and superposition theorem are applied to analyze the steady-state and dynamic behavior of a 3p-DAB converter. According to the analysis results, two dynamic control approaches are presented to enable converters transfer from one steady state to another one within one-third and two-third switching period respectively. Finally, a laboratory prototype has been built and the theoretical analysis is verified by experimental results.