Dead-time effect analysis of a three-phase dual-active bridge DC/DC converter
The dead-time effect is observed in the three-phase dual-active bridge (DAB) DC/DC converter. The occurrence of the dead-time effect depends on the relationship of the switching frequency, the phase shift value, the dead-time value and the equivalent conversion ratio. The dead-time effect may have a significant impact on the converter performance when high switching frequency, wide input and output voltage range or wide operation power range are required. Therefore, comprehensive research of the dead-time effect is essential to improve the design of the three-phase DAB converter over a wide operation range. In this study, all the cases of the dead-time effect in the three-phase DAB converter are analysed in terms of the buck, boost, and matching states. The expressions of the transmission power, constraint conditions, and key time of the dead-time effect are derived for each state. The operation waveforms of the dead-time effect are also presented to better understand the dead-time effect. Finally, the analysis is verified by both simulation and experimental results.