Analysis of Multi-Harmonic Magnetic Field Coupling Characteristics of Bearingless Permanent Magnet Synchronous Motor

The suspension performance is an important evaluation index of the bearingless motor, which is the key to avoiding shutdown caused by stator and rotor collisions, as well as the safe and stable operation of the motor. In this paper, an Accurate Decoupling Mathematical Analysis Method for Multi-harmonic Magnetic Field Based on Maxwell Tensor Method. On the basis of the mathematical analysis model of the suspension performance and the analysis of the air gap multi-magnetic field, the weight classification of the influence of coupling magnetic field on radial suspension force is studied. The spatial distribution and temporal variation of the suspension force and its fluctuation are analyzed according to the coupling relationship involving the constant, fluctuating components and the space-time vector in the space-time vector expression of the suspension force, and the relationship between the space–time coupled magnetic field and the suspension performance is obtained. Further combined with numerical analysis, the effect of polar arc eccentricity on suspension performance is analyzed, the optimal eccentricity for suspension performance is found, and the effect of the harmonic magnetic field of permanent magnets on the fluctuation of levitation force is verified. Finally, the prototype is made, the experimental platform was built, and the experimental platform is constructed to test the static and the dynamic performance of the prototype.