An Integrated EMI Choke With Improved DM Inductance

Utilizing electromagnetic interference (EMI) filters is a major approach to reduce the conducted emissions from the power electronic converters. These filters enlarge the total volume and weight of the system. Many works have been done to integrate the filter components. In this article a new integrated choke with a certain winding structure, consists of two core, a toroid, and a solenoid is presented. Although the DM inductance of the proposed choke could be independently increased by designing the windings, the CM inductance value remains almost constant as the conventional choke. Theoretical analysis for modeling the choke and prediction of the inductances and saturation conditions is provided. Experimental measurements validate the analysis, and show a good filtering performance with rejecting conducted noise from an induction motor drive system while it decreases the overall filter size.