Stability Analysis and Optimization of Dual Active Bridge Converter with LC Input Filter

The dual active bridge (DAB) converter has been widely applied in energy storage systems because of the high-power density, galvanic isolation and soft switching properties. However, the interaction between the DAB converter and its LC input filter may cause unstable problems. To address this stability issue, the full-order impedance model of the DAB converter is firstly developed based on generalized state-space averaging method. The developed impedance model can be used to accurately predict the stability of the DAB converter with its LC input filter. Based on the developed model, the effects of the LC filter on the system stability are revealed. Furthermore, the stability-oriented filter design guideline is provided. The optimized filter parameters can improve the stability of the system. Finally, the impedance model and stability analysis are validated by the comprehensive simulation and experimental results.