Analysis of common- and differential-mode HF current components in PWM inverter-fed AC motors

In this paper, an inverter-fed AC motor drive is analyzed in order to predict the conducted interferences at both the input and output sides of the inverter. HF lumped equivalent circuits for the inverter and the motor stator winding are proposed. The equivalent circuit allows time and frequency domain analyses to be performed with standard circuit simulators. The overall circuit model is verified by experimental tests carried out on a prototype of the AC motor drive. The proposed circuit model allows the prediction of the main common and differential mode HF current components.