Full Electromagnetic Integration of Impedance-Balanced EMI Filters for Single-Phase Power Converters

Abstract

Utilizing passive electromagnetic interference (EMI) filters is the most widely used approach to restrain the conducted emissions from power converters. However, the introduction of these filters will significantly raise the weight and size of the systems. Using the emerging flexible multi-layer foil (FMLF) technique, this paper investigates a complete electromagnetically integrated design concept of single-phase EMI filters based on EE-type cores, which can be applicable to engineering application scenarios with different EMI noise attenuation requirements. Two types of integrated structures are constructed with different well-designed FMLF-windings and terminal configurations. One is a common-mode (CM) choke with controllable leakage inductances, which is able to realize the integration design of CM inductor, CM capacitors and differential-mode (DM) inductors. The other is an EMI choke with integrating the CM and DM inductances & capacitances, which achieves electromagnetic integration of all the CM and DM filtering components. Compared to the existing UU-type core based integration methods, the proposed methods can ameliorate the noise suppression performance while reducing filter's weight and volume. Theoretical analyses for modeling and design of the EMI chokes is presented. Then prototypes of different FMLFs based EMI filters have been built for a 500W 100kHz SiC-MOSFET inverter, experiments demonstrate the feasibility and validity of the proposed structures.