Comprehensive CM filter design to suppress conducted EMI for SiC-JFET motor drives

Abstract

This paper proposes a comprehensive EMI common-mode (CM) filter design procedure to suppress conducted EMI in silicon carbide (SiC) JFETs based inverter-fed motor drive systems. The first part of this paper is focusing on analyzing the EMC issue arisen from the newly generated power semiconductor device - SiC JFET, where the switching dynamics of SiC JFET and Si IGBT with the same power flowing level are compared. Then the second part towards EMI suppression for the inverter prototype. A comprehensive EMI CM filter design procedure is proposed. The proposed CM equivalent circuit model is able to evaluate the filter insertion loss gains over the whole conducted EMI frequency range, thereby different filter topologies can be compared and optimally selected. The performed experiments form the guideline that exhibits the process how the generated conducted EMI from the built inverter prototype is successfully suppressed to comply with the IEC61800-3 standard step by step.