Modeling and Minimization of Switching Loss in Dual Active Bridge Converters

This paper presents a closed-form formulation to model the switching loss in single-phase dual active bridge converters (DAB). The proposed model is general and covers all modulation techniques with one, two, or three control parameters. Moreover, in this paper, the switching loss is minimized in a DAB converter controlled by the extended phase shift modulation (EPS) utilizing the model. In other words, the proposed loss model is used in a standard nonlinear optimization approach targeting the switching loss. By this optimization, the efficiency of the DAB converter is improved notably. Particularly, in IGBT-based converters with high switching loss, the optimization approach reveals significant improvement. In the designed 10kW DAB converter controlled by EPS modulation with optimal parameters, the switching loss is reduced by 22% compared to the traditional single-phase shift modulation (SPS). The total efficiency is increased by 0.6%, employing the proposed model and the optimization process.