The fabrication and application of CM/DM interference separation network based on transmission-line transformer

Power electronic equipments generate differential-mode (DM) and common-mode (CM) interference simultaneously, both the propagation path and suppression method of these interferences are different. For reducing cost of interference suppression, it is very useful to identify the CM interference and DM interference in power electronic equipments, especially in the high-power equipments. The principle, fabrication and application of CM/DM separation network is introduced in this paper. A CM/DM separation network based on the transmission-line transformer is fabricated, and the performance parameters of this network are measured. Finally, the interferences generated by an actual switch-mode power supply are identified with this CM/DM separation network.