A novel control strategy based on modified gating scheme for a dual-active-bridge converter

High frequency (HF) isolated dual active bridge (DAB) converters are featured with high power density, high efficiency for bidirectional applications. For the conventional single-phase-shift (SPS) control, all the switching devices of the DAB converter can work at zero-voltage switching (ZVS) for the entire power range, only when the voltage conversion ratio is equal to one. Various pulse width modulation (PWM) techniques for bidirectional converters exist to extend the zero-voltage switching (ZVS) operation range when the voltage conversion ratio is not equal to one. In this paper, a novel control strategy based on a modified gating scheme is adopted for the DAB converter to realize ZVS operation for the whole load range. Verification of the analysis are performed through simulation and experimental results.