Abstract：The flexible DC interconnection of medium and low voltage can improve the flexibility and

reliability of the distribution network，and the dual active bridge converter is a key link in achieving voltage

conversion and electrical isolation in flexible interconnection equipment.The current source resonant dual active

bridge utilizes DC capacitors to participate in resonance and soft switching design，which can significantly improve

the power density and efficiency of the dual active bridge. However，there are significant differences in the

characteristics between the current source resonant dual active bridge and the traditional voltage source resonant

dual active bridge. The resonant cavity is composed of a DC resonant capacitor and an AC side resonant inductor，

which leads to complex time-domain modeling of high-frequency current and affects the frequency design of zero

current switching（ZCS），making it difficult to obtain analytical expressions for the ZCS switching frequency and

resonant frequency. An equivalent circuit modeling method for high-frequency isolation links based on fundamental

components from a frequency domain perspective was proposed，established an analytical relationship between

ZCS switch frequency and resonant frequency，and verified the effectiveness and accuracy of the proposed method

through simulation and experimental results.

     Key words：dual active bridge；current source；resonance；high-frequency link modeling；zero current

switching（ZCS）soft switching