Improved Active Disturbance Rejection Control for the DAB Converter with 4-DF Modulation

The 4-degree-of-freedom (4-DF) modulation with frequency adjustment and triple-phase-shift control can enhance the efficiency of the dual active bridge (DAB) converter. To improve the dynamic response performance of DAB under 4-DF modulation, an improved auto disturbance rejection control (IADRC) strategy is proposed. Firstly, the mathematical model from the virtual power to the converter's output voltage is established, and the basic structure of ADRC under 4-DF modulation is given. Secondly, the performance of the ADRC with fixed parameters is studied, and simulation results reveal the contradiction between the dynamic and static behavior of DAB. A virtual-load-current-based IADRC strategy is then proposed to solve this contradiction, which realizes an online auto adjustment of the controller parameters. Finally, a multi-objective cuckoo search optimization algorithm-based tuning method of IADRC parameters is proposed. The experimental results show that the proposed control strategy can significantly improve the dynamic response performance of the DAB converter while achieving efficiency optimization.