LAUSR

The rotating characteristic and the stability analysis of unsymmetrical magnetically suspended motor (MSM) are investigated in the article. Firstly, the dynamic functions of unsymmetrical MSM with different moment of inertia ratios and suspension span ratios are developed. Based on the equation of radial rotation, the open-loop pole and the frequency response are analyzed, so relationships among critical whirling frequency, moment of inertia ratio and suspension span ratio are established. Moreover, relationships among rotating characteristic, moment of inertia ratio and suspension span ratio are investigated, and then the rotation stability criterion of unsymmetrical MSM based on dual-frequency bode diagram is developed. Finally, the results prove that the proposed rotation analysis method is a potential way to analyze rotating characteristic of unsymmetrical MSM.