Simplified State-Space Average Model and Control Strategy for the Dual Active Bridge Power Converter

This paper presents the simplified state-space average model of the Dual Active Bridge (DAB) power converter which eliminates the complexity in Fourier based model of the transformer excitation system. The proposed model has used for developing a current control and a multiple loop voltage control strategy for the bidirectional converter. The model derived in this paper can be easily used for the bi-directional converter topology employed in the application of fuel cell, electrical vehicle battery charging, solar water pumping projects, etc., where voltage ports with large voltage difference are encountered. Nowadays, in several power applications, bidirectional converters with galvanic isolation are in demand due to their lightweight and reasonable efficiency and a quick turnover of the design is desirable. The simplified model of DAB converter is used for compensator design and control strategy formulation. This model and analytically derived parameters are verified by simulations. All the relevant simulation results are provided in this paper to demonstrate the efficacy and validity of the proposed model for DAB converter. The presented work in this paper provides a guideline of close loop control design for several other applications of DAB power converter using its simplified model.