Modeling and Optimization Design of Active Common-Mode EMI Filters for DC/AC Power Converters

As power electronics move to high power density, electromagnetic interference (EMI) filters play a greater role in power converters. The application of active EMI filters (AEF) effectively reduces the size of passive filter components. However, there is still room for further improvement in AEF optimization design research. This paper first analyzes the compensation mechanism of AEF and establishes its detailed internal model. Then, insertion loss is derived to guide AEF optimization design based on the common-mode circuit model, and the influence of key parameters on insertion loss in each frequency band is analyzed. Thus, AEF parametric optimization design guidance is finally given. The experiment proves that the suppression effect is improved through optimization design without increasing the filter volume.