ZVS Control strategy of dual active bridge DC/DC converter with triple-phase-shift modulation considering RMS current optimization

Dual active bridge (DAB) DC/DC converter is an ideal high-power bidirectional DC/DC converter with multiple control methods. In this paper, the working characteristics of the DAB converters are analysed by the example of medium power mode, in which the voltage transfer ratio is less than 1. For the situation that the DAB converter is difficult to achieve soft switching at light load, a triple phase shift (TPS) control method is used. Combining with RMS current optimisation, a control method to achieve soft switching for full-power range is proposed. The control strategy enables the converter to realise zero voltage switching (ZVS) of all the switching device, which not only improves the operating conditions of the switching device, but also improves the converter efficiency. Finally, a prototype of DAB was built. Compared with the traditional control method, the experimental results verify the effectiveness of the proposed control strategy.