High-Frequency Induction Drive Analysis for Common Mode and Differential Mode Impedance Characteristics

The parasitic currents issue arises in induction machines operating at higher frequencies. The parasitic current flow is the main cause of premature degradation of winding insulation deterioration and bearing damage. The effect of electromagnetic interference (EMI) requires investigating an equivalent per-phase model of an induction motor (IM) at higher frequencies. The per-phase induction motor mathematical model of the IM 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 (2021b) is developed to generate the transfer function of IM drive and generate bode plots for both CM and differential mode (DM) impedance configuration at higher frequency. Initially, the IM typical frequency response without considerations of stray and parasitic effects is presented for normal behavior of the IM. In order to verify the simulated impedance parameters of 0.3 kW and 38 kW IMs with stray and parasitic components, a 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. The analysis suggests that 38 kW IM resonance occurs in MHz range which exhibits much better performance compared to the 0.3 kW IM model.