Impedance compatibility analysis of EMI filter based on circuit model

In this paper, the hybrid active electromagnetic interference filter (HAEF) is proposed to improve the power quality. A systematic classification and identification of HAEF configurations is given, including their insertion losses, impedance compatibilities, potential applications, and comparative features. It is aimed at providing a broad perspective on the status of HAEF technology to researchers and application engineers dealing with EMI issues. The basis of discussion is an equivalent circuit model that includes all possible combinations of active and passive elements and matches these to the desirable attributes. The evaluation indicates those topologies that are known and those topologies that are relatively new.