Numerical Identification of Electromagnetic Force Parameters for Linearized Rotordynamic Model of Cage Induction Motors

The electromechanical interaction in cage induction motors induces additional forces between the rotor and stator. Recently, a linear parametric model was presented for these forces, and the corresponding model was combined with a mechanical rotor model. The electromagnetic system is usually non-linear due to the saturation of magnetic materials. Thus, the effective identification of the force parameters is crucial. Initially, the parameters were identified numerically from the response induced by the whirling rotor. Later on, a method based on the impulse response analysis was presented. The aim of this study was to present the theoretical background of this impulse method, and to present some useful additional features. The derived equations show the mathematical equivalency of this impulse method and the previous whirling method. The results show that the impulse method is numerically effective. In addition, the feasibility of thus obtained simple electromechanical rotor model was demonstrated.