A Transition Completion Detection Circuit for Dual Active Bridge Converters

Abstract

Dual-Active-Bridge (DAB)-liked converters owning the inherent soft-switching capability, hence, they can achieve very high system efficiency. In order for soft-switching to achieve, the body diode of a MOSFET should conduct before the switch is triggered. This diode conduction occurs in the dead-time. If the dead-time is large, diode conduction loss may be significant that leads to the downgrade of system performance. This unwanted loss can be eliminated by triggering the MOSFET right at the instant when the transition completed. This paper proposed a method to detect that instant By using several low-cost passive components, a transition detection circuit can be built which can detect both the tura-on and turn-off transition completions. The effectiveness of the circuit is verified by simulation for DAB converter applications. However, it can also be used for detecting transition of other bridge-typed power electronic converter topologies.