LCL filter design with EMI noise consideration for grid-connected inverter

Abstract

The grid-injected current total harmonics distortion (THD) and electromagnetic interference (EMI) noise must be considered in a transformer-less grid-connected inverter for a more electric aircraft (MEA) system. This paper develops a procedure for the design of the magnetic components of the LCL filter used in harmonic control and EMI reduction of the silicon carbide (SiC) grid-connected inverter in the MEA. The LCL filter is designed with effective harmonic attenuation and a compact size. To meet the space constraint requirement, specific design attention is focused on a customized amorphous cored inductor, with a comprehensive study of the relationships of inductor winding with respect to EMI noise. Reduced THD and EMI are verified through experiments performed on a 30 kW, 230 V/400 Hz three-phase grid-connected inverter prototype with the LCL filter.