Abstract: A second order filtering power dividing frequency control strategy based on virtual impedance was proposed. The different frequency power compensation among different storage units by building invisible pass filters was achieved. The invisible pass filters including high pass filter and low pass filters were constructed by virtual capacitance loop and virtual inductance-resistance loop. Firstly，hierarchical control system of DC microgrid was introduced. Secondly，the operation and topology of LCLC resonant three-port converter were introduced.Finally，the proposed power dividing frequency control strategy of second order filtering based on virtual impedances was analyzed in detail.

      Key words: LCLC resonant three-port converter；DC microgrid；hierarchical control；second order filtering；

virtual impedance