Multiphysics Modeling of Direct-Start Induction Motor Considering Rotor Unbalance

Abstract. The paper proposes a multiphysics model of the dynamics of an induction motor with a squirrel-cage rotor, taking into account the forced vibrations caused by the mass and magnetic eccentricity of the rotor. The model is based on numerical modeling of the motor operation, analytical modeling of the motor oscillations with a rotor containing mass eccentricity and numerical modeling of the motor oscillations with a rotor containing static and dynamic magnetic eccentricity. The model makes it possible to simulate vibrations of rotors and induction motor casings with account of moments of unbalanced forces of mechanical and electromagnetic nature. The model takes into account the polyharmonic nature of vibrations and makes it possible to study their effect on the electrical and energy parameters of the motor during acceleration during direct start and in steady-state mode. As a result of numerical simulations of a three-phase induction motor, it was found that the maximum permissible vibrations increase power consumption by 5% in steady-state mode and by 10% during direct start.