Frequency model for differential-mode conducted EMI prediction in three-phase PWM inverter

This paper presents a simple frequency-domain model to predict the differential-mode (DM) conducted electromagnetic interference (EMI) noise in three-phase PWM inverter. The main DM EMI source in the three-phase inverter includes two currents: the load current and the reverse recovery current of the diode. The amplitude spectrum of the DM EMI source is analyzed and modeled by current source in the frequency-domain. The parasitic components are identified using network analyzer. The calculated DM EMI result is compared with the experimental data. It is verified that the model presented in this paper can be used to predict the DM EMI generated by the three-phase PWM inverter.