Minimum Current Optimization of DBSRC Considering Dead-time Effect

Abstract

In the dual-bridge series resonant converter (DBSRC) working at a high switching frequency, the dead-time effect becomes a serious issue. When the minimum current trajectory (MCT) method is applied, the inductor current cannot be minimized due to the dead-time effect, and the range of the soft switching is reduced. Considering the dead-time, this paper firstly performs a theoretical analysis of the transmission power and soft-switching characteristics based on the fundamental harmonic approximation (FHA) approach. Then, a minimum current trajectory method considering dead-time (MCT-d) is proposed to achieve minimum inductor current by compensating the dead-time. Meanwhile, the method can extend the soft-switching range as well. Finally, the experimental results validate the theoretical analysis and the improvement of the converter efficiency.