Background and Purpose: The stator vibration characteristics are comprehensively mastered by considering the influence of winding and the housing structure on the stator modes. This effect is neglected in the research field of electromagnetic vibration of permanent magnet synchronous motors (PMSMs). Methods: The radial air-gap flux density equations and PMSM’s electromagnetic force density are derived, and then the harmonic characteristics of electromagnetic force density are studied. An equivalent finite element model of the stator is proposed that investigates the impacts of the winding and stator housing rules on the stator modal frequency. Finally, the harmonic response and acoustic analyses of electromagnetic vibration are carried out based on multi-physics field coupling. Results: The equivalent radiated power distribution laws and acoustic field of motor electromagnetic vibration under transient operating conditions are obtained. The theoretical analysis results are consistent with the experimental results. Conclusion: The obtained results show that the spatial order of the radial electromagnetic force is not equal to the order of the radial mode of the motor stator. The reason for this is that structural resonance is induced when the frequency components of the spatial radial electromagnetic force are coupled with the intrinsic frequency of the stator.

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Sliding mode control has good robustness, but the traditional sliding mode has the problem of chattering. Aiming at the conflict between velocity and chattering in the approach stage of sliding mode control, a new reaching law is put forward. By improving the isokinetic approach term of the traditional exponential reaching law, the system’s requirements in different stages of sliding mode motion are met, and this contradiction has been effectively improved. At the same time, to better improve the control effect of permanent magnet synchronous motor (PMSM) speed regulation system, combined with the traditional PI control with no static error and no overshoot, a combined speed controller combining sliding mode control and PI control is designed to enhance the robustness of the system. By building a model in Matlab/SIMULINK for simulation, the effectiveness of the improved exponential reaching law and the improvement of the system performance brought by the combined speed controller are verified respectively.

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