Full soft-switching capability of the dual-active bridge by using the auxiliary-resonant commutated-pole technique

Many publications present the extension of the soft-switching range of the dual-active bridge (DAB). Unfortunately soft-switching over the entire operating area of the DAB is hard to realize. In this paper, the loss reduction of a 5 MW dual-active bridge using the auxilary-resonant commutated pole technique are derived by simulation. The aim of this technique is to improve the converter's efficiency. To reach that goal each phase is extended with an auxiliary-resonant pole to force a soft-switched commutation of the converter legs to prevent switching losses. Basic control algorithms are presented and proper controllability is demonstrated by a small-scale setup.