Suspension Force Modeling for a Bearingless Permanent Magnet Synchronous Motor Using Maxwell Stress Tensor Method

Bearingless permanent magnet synchronous motors (BPMSMs) have been received more and more attention during the past few decades. To realize the high-performance control for rotation and levitation, we will first need to obtain the accurate suspension force model of a BPMSM. In this work, different from conventional suspension force models, a modeling scheme for the suspension force of a BPMSM is presented by taking into account rotor eccentricity with the Maxwell stress tensor modeling scheme. The theoretical value of a suspension force model is compared by the two-dimensional finite element (FE) analysis, and calculation results reveal that the theoretical value closely agree with the FE computed one. Furthermore, the digital control system is devised by taking advantage of TMS320F2812, and a test platform for experiments is then set up. In accordance with the corresponding findings of the experiments, the rotor stabilization with magnetic levitation can be achieved. The results lay a theoretical and experimental foundation for further study of the BPMSM.