Transient current balancing modulation for seamless load step response in a dual-active-bridge converter with triple phase-shift control

With the load step demands, the dual-active-bridge dc-dc converter might be arsing a temporal dc offset and overshoot current in the inductor and transformer due to improper direct modulation. The dc offset and overshoot current often causes a series of complex electromagnetic problems and bring up extra conduction loss into the system. In this paper, a dedicated transient current balancing (TCB) modulation for seamless transient response is proposed. The triple phase-shift (TPS) control, a three dimensional gating signal scheme is selected as the research target. The proposed TCB modulation are checked for all transition cases between different TPS steady state modes. To minimize the dc offset, the TCB modulation adjusts the selected phase-shift by referring a floating reference. Consequently, a fast transient response without dc bias current of TPS control can be obtained. And, the proposed TCB modulation can easily determined by a uniformed solution which is irrespective of steady state. All theoretical works have been validated by both simulation and actual experimental test.