Low-order parametric force model for eccentric-rotor electrical machine equipped with parallel stator windings and rotor cage

In the paper, a new low-order parametric force model for an electrical machine with eccentric rotor is developed and verified. The model is designed for an electrical machine equipped with both the parallel stator windings and rotor cage, and, therefore, accounts for the equalising currents in the stator and rotor windings separately and also for their influence on each other. Furthermore, the model can also be used with an electrical machine having either the parallel stator windings or the rotor cage. The presented model with parameters estimated from the numerical test results demonstrated a very good performance in a wide whirling frequency range. The proposed model provides an opportunity to combine effectively the electromagnetic and mechanical analyses of the electrical machine.