The paper proposes a secondary ripple suppression method based on variable inductors for an isolated AC-to-DC converter. Unlike traditional traditional methods, it uses a variable inductor module with an auxiliary current source to replace the front-stage resonant inductors of the DAB converter. By varying the inductance, it effectively suppresses secondary ripples without impacting the converter's control strategy. Models are established to derive ripple expressions and explain the variable inductor's principle. Simulations show a significant reduction in ripple peak and a notable increase in circuit efficiency under the same load, validating the analysis and method's feasibility.
 

Isolated AC-DC Converter; Magnetic Circuit Control; Power Quality; Secondary Ripple Suppression; Variable Inductor