Modelling of Input-Series and Output-Parallel DAB Converter Under Triple Phase Shift Modulation

This paper proposes a modeling method for the input series and output parallel (ISOP) dual active bridge (DAB) converter under triple phase shift (TPS) modulation. Moreover, the reduced-order state-space average (RSSA) model is established to further obtain its equivalent small signal circuit model both for DAB and ISOP DAB converter. The model shows that the ISOP-DAB converter is a multi-input and multi-output (MIMO) system, the decoupling algorithm is adopted to convert the MIMO system to single-input and single-output (SISO) system, which is convenient for the control parameter design of the controller. Besides, the decoupled transfer function of ISOP system is approximately first order system. Finally, the correctness of the modeling method is validated by simulation in time and frequency domain.