High Frequency Induction Motor Analysis for Common Mode and Differential Mode Impedance Characteristics

The parasitic currents issue arises at high frequency operation of induction motor. The flow of parasitic currents is the main cause of premature deterioration of winding insulation and damage to the ball bearing. In order to comprehend the effect of electromagnetic interference (EMI) an equivalent per-phase model of an induction motor should be investigated at higher frequencies. The per-phase induction motor mathematical model of induction motor drive for common mode (CM) configuration is developed to perform high frequency analysis for drive operation. The high frequency per phase induction motor model MATLAB model is developed to generate the transfer function of IM and generate bode plots for CM and differential mode (DM) impedance configuration for high frequency analysis. The induction motor typical frequency response without considerations of stray and parasitic effects is presented for normal behavior of IM. In order to verify the simulated impedance parameters of 0.3 kW and 38kW induction motor with stray and parasitic components. High frequency response for magnitude and phase response is generated and compared to analyze per phase induction motor model performance before and after resonance frequencies. The comparison of CM and DM bode plots validates the dominance of inductance and parasitic capacitance before and after the occurrence of resonance frequency respectively.