Abstract：Cascading LC filter at the input of the dual-active-bridge (DAB) converter can improve the input current quality. However, the interaction between the DAB converter and LC filter easily leads to the oscillation phenomenon of the LC-DAB cascaded system. Therefore, the state space averaging small signal mathematical model of the DAB converter is firstly established, and the input and output impedance models of the LC-DAB converter are derived for predicting the stability of the cascaded system. Then, a parallel virtual impedance control strategy based on the primary side capacitor voltage of the LC-DAB converter and a series virtual impedance control of the primary side current are proposed respectively. Thus, the cascaded system can operate stably in the full power range. The experimental results verify the validity and correctness of the impedance model and control strategy.
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2021, Vol. 36 
