Abstract:
By using multi-level circuits, the dual active bridge (DAB) DC/DC converter can achieve higher voltage level, higher power density and better performance. This paper firstly analyzes the dead-zone effect of the active neutral point clamed five-level (5L ANPC) circuit when used in DAB converter, then a DAB based on a nine-switch 5L ANPC circuit is proposed, where the dead time effect is eliminated by a zero state with dual current paths. On this basis, through the analysis of the switching process, the zero switching states selected in this paper realize the soft switching operation of all high-voltage power switches. Furthermore, through the analysis of the effects of different switching sequences on flying capacitor voltage and neutral point voltage, a control strategy is proposed to ensure the voltage balancing of flying capacitor. The experimental results on a 1kW experimental prototype show that the proposed 5L ANPC DAB converter achieves good performance.