Electromagnetic Integration of a Symmetrical LCL-EMI Filter for Grid-Connected Voltage-Source Converters

Switching harmonics and conducted electromagnetic interference (EMI) emissions are two challenging issues in grid-tied converters. Utilizing relevant passive filters is a major solution to such issues, these filters enlarge the total volume and weight of the system. Many works have been done to integrate the filtering components to varying degrees. For achieving the highest integration design, this paper proposes an ultimate integration approach of a symmetrical LCL-EMI filter with flexible multilayer foil (FMLF) technique. All the harmonic and EMI suppression components are integrated into the same core unit. A prototype of the proposed integrated filter is built for a 1-kW SiC-MOSFET grid-tied inverter, experiments are carried out to demonstrate the feasibility and superiority of the approach.