Bearingless motor´s radial suspension force control based on virtual winding current analysis

Decoupling control of torque and suspension force is the key technology to achieve stable operation for bearingless motors. In this paper, after a general introduction of the principle of radial suspension forces for the bearingless permanent magnet synchronous motor (BPMSM), a new analysis method based on virtual winding current is presented. Based on the proposed analysis method, the corresponding theoretical analysis of suspension operation is presented. Meanwhile, the control strategy of stable operation is put forward for the BPMSM. In order to testify the validity of the proposed analysis method, the relevant experiments are designed and conducted. It can be concluded that the experiment results are very close to theoretical analyses based on the proposed method. Moreover, the validity of control strategy can be confirmed, which establishes foundations for further research.