A Unified Electromagnetically Integrated LC and LCL Filtering Module With Adjustable Configurations for EV Converters

LC-type and LCL-type filters are generally employed in the power converters of electric vehicles (EVs) for attenuating the associated switching harmonics introduced by modulation schemes. The passive filters commonly occupy prominent footprints, spaces, and weights, which goes against the high power-density demand of EVs. In order to tackle these concerns, this article investigates a shared electromagnetic integration approach with a flexible multilayer foil (FMLF) technique for both LC-type and LCL-type filters. Based on the fundamental design concept of the FMLF technique for achieving electromagnetic integration of an LC low-pass module, EIE-shape magnetic cores and two regular FMLF windings are utilized for the design. The negative influence induced by magnetic coupling between the two windings can be mitigated by reasonably regulating the air gaps designed between E-shape and I-shape cores. Additionally, through properly adjusting terminal configurations of the FMLF windings, the integrated module can switch between LC and LCL filtering modes as desired. The harmonic attenuation capability and conducted electromagnetic interference (EMI) suppression capacity of the module are discussed, following which, the design guideline of the integrated module is introduced. Finally, the feasibility and validity of the proposed approach are demonstrated by the simulations and experiments carried out with a 1-kW SiC-MOSFET voltage-source converter.