A Periodic-Steady-State Analysis Model in Time Domain for Dual Active Bridge Converter

This article forms a multitime-scale modeling method through a time-domain analysis, using both ideal steady-state processes and finite switching transient processes for increased accuracy of dual active bridge (DAB) converters. All possible operating modes and the corresponding state equations are derived from the switching transient process for a five-degrees-of-freedom-modulated DAB converter based on the unified equivalent circuit. The nonlinear parasitic capacitors are considered in this process. A periodic-steady-state analysis model is established to accurately predict the residual voltage under incomplete zero-voltage switching. This method is applicable for all phase-shift-modulated DAB converters, and the calculation time is reduced 28-61 times compared with LTspice simulation. Finally, the simulation and experimental results are compared to validate the effectiveness of the model.