A New EMI Modeling Method for Mixed-Mode Noise Analysis in Three-Phase Inverter System

Abstract

A novel frequency-domain EMC modeling technique is proposed to predict the conducted electromagnetic interference (EMI) in a three-phase inverter system. On the basis of the frequency-domain model, a three-terminal behavior model for analyzing mixed-model (MM) noise is derived. Different from the traditional model, the CM and DM noise sources are independent of each other, thus help to understand the MM phenomenon directly. It is shown that three stray capacitors in the IGBT module determine the amplitude of the MM noise, and the influence of the load current on the traditional CM and DM noise sources can be used for the MM noise observation. The simulation and experimental results are illustrated to verify the prediction technique and the MM noise analysis is confirmed.