Analysis and Modeling Framework of Common Mode Noise in a Three-phase Motor System

Electromagnetic interference (EMI) issue is one of the major constraints of power electronic converters, especially for variable-speed systems. In this work, the common mode noise in a three-phase motor system is analyzed and modeled. The three-phase pulse-width modulation (PWM) inverter creates high magnitudes of dv/dt and di/dt, resulting in common mode noise and disturbance power. In this paper, the common mode noise and disturbance power modeling method are proposed for three-phase motor systems. The proposed equivalent circuit model comprises detailed models for insulated gate bipolar transistors (IGBTs), EMI filters, a three-phase motor and a printed circuit board (PCB). The proposed model of a three-phase system was verified by measurement with and without additional Y-capacitors. The measured and modeled common-mode noise shows a correlation in broadband common-mode noise reduction.