Magnetic Integration Techniques of Inductors Used in a Buck Converter with EMI Filter

Abstract

This paper presents the approaches to integrate all inductors used in a buck converter with EMI filter. First approach, a buck inductor and a CM choke are integrated using UIU and EI magnetic core types with proposed winding configurations. In the second approach, a buck inductor, a DM choke, and a CM choke are all integrated into single EIU magnetic core type with proposed winding configurations. The DM and CM reduction performances of the cases of buck converter: without any filter inserted, with filter using conventional discrete magnetic cores, and with filter using proposed integrated magnetic cores are evaluated and compared. From the experimental results, it can be concluded that there is no different among all cases for DM comparisons. However, for the CM comparisons, the integrated magnetic core using EIU core type provides the best CM reduction performance. © 2019, The Korean Institute of Electrical Engineers.