An adaptive dead-time control scheme for high-switching-frequency dual-active-bridge converter

In high-switching-frequency isolated dc-dc converters, dead-time has a great influence on the switching transition behavior of switching devices. Fixed dead-time is determined by the longest required dead-time and results in missing zero-voltage-switching (ZVS) in some operation conditions, which causes undesirable switching stress and ringing, and efficiency degradation of converter. This paper proposes an adaptive dead-time control scheme for the high-switching-frequency dual-active-bridge (DAB) dc-dc converter. The proposed scheme feedbacks the V_ds of primary side switch and can auto-tune the dead-time to make the primary side switching devices work under zero-voltage condition and to increase the converter efficiency. The scheme was implemented in a 5 kW 500 kHz DAB converter prototype, and the experimental results verified the effectiveness of proposed scheme.