Investigations on Winding Modeling Techniques for Electrical Stress Analysis in VSI-Fed Traction Electric Machines

Traction motors are exposed to high dv/dt pulses when driven by a voltage source inverter (VSI). Due to this type of voltage excitation, machine's winding insulation system experiences additional dielectric stress, which can result in premature insulation failure in the machine windings. To analyze this electrical stress, various modeling techniques have been presented to model the machine windings, which can predict the voltage and current distributions among coils and turns of the windings. In this paper, different modeling techniques are investigated. Comparative analysis and results from case studies of the selected modeling techniques are presented.