Radial Force Modeling of bearingless Motors Based on, Spectral Analysis of Field Sources

This paper proposes a global harmonic analysis of a multiphase bearingless PM-motor topology to determine the radial force by considering normal and tangential field components. This allows establishing the semi-analytical expressions of the radial force considering the location of field origin. The accuracy of the model is verified by full FEM model using a statistic approach. The semi-analytic model allows predicting the force waveforms according t the stator-rotor topology. The analysis of two specific topologies is performed and highlights the origin of force ripples. The fastness of this semi-analytical model makes it suitable to implement in a design optimization process.