HF induction motor modeling using automated experimental impedance measurement matching

High-frequency (HF) models of electrical motors and power converters are greatly important for electromagnetic compatibility characterization of electrical drives and for electromagnetic interference (EMI) filter design. In this paper, an accurate and effective method for the characterization and tuning of HF models (150 kHz-30 MHz) for induction motors has been proposed based on experimental measurements of the motor impedance. Impedance measurements have been taken in three different configurations: between all the six winding terminals which are shorted and grounded; between the three input terminals which are shorted and grounded (common mode); and between one input terminal and the other two which are shorted (differential mode). Once an HF motor model structure has been chosen and modeled using a state-space representation, its parameters have been tuned using genetic algorithm to match the real impedance in each corresponding configuration. Comparison between the experimental impedance measurements and the model impedance estimate are shown for all the tested configurations, in order to validate the model within the frequency range of interest for EMI.