Transient Modeling of Induction Motors considering Space Harmonics

This paper presents a transient mathematical model for induction motors based on space harmonics and its validation by finite-elements method comparison. The model is based on the computation of the magnetomotive force-wave for squirrel cage induction motors, and accounts for the geometry and physical dimensions of the stator and rotor windings. The harmonic components of the airgap field are calculated at each time-step considering the currents in the stator windings and in the rotor bars, the latter modeled as overlap of contiguous coils, as well as the rotor position. The proposed model is compared with finite elements calculations to outline differences and effects of simplifications and harmonic order. A 200kW induction motor designed for a premium electric vehicle is assumed as case-study.