Small Signal Model of Dual Active Bridge Converter for Multi-Phase Shift Modulation

The derivation of small signal model of bidirectional dc-dc dual active bridge (DAB) converter under multi-phase shift including the conventional single phase shift (SPS), dual phase shift (DPS) and triple phase shift (TPS) modulation is presented in this paper. Full order continuous time generalized average model has been developed for different modulation strategies and control variables to output voltage transfer functions analytical equations have been derived. Also, open loop responses of the DAB converter based on the developed model have been plotted and frequency response estimation simulation is performed in Simulink to compare the accuracy of the model. Finally, a proportional integral (PI) controller has been designed for each of the modulation methods and the effectiveness of the controller has been demonstrated through simulation.