Improved Load Transient Response of a Dual-Active-Bridge Converter

Abstract

In this work, the transient response of a dual-active-bridge (DAB) converter to load-change command is investigated under dual-phase-shift (DPS) control. During the transient process, there might be dc bias current and overshoot current arising in the inductor and transformer due to improper transient modulation. A dedicated transient modulation method is then proposed, which adjusts all phase-shift ratios by referring to a floating reference gating signal. Consequently a fast transient response can be obtained without dc bias current and overshoot current. The dynamic movement of the floating reference signal can be determined easily by a uniformed expression irrespective of the different steady state operation modes. The proposed transient control has been proved through simulation and experimental results.