| Fractional-slot concentrated-windings(FSCW)permanent magnet synchronous motors(PMSMs)possess several advantages,including high power density,simple structure,and superior control performance,which have led to their widespread utilization in various applications.However,the vibration and noise generated during the operation of the permanent magnet synchronous motor directly affect the reliability,concealment,and comfort of the drive system.Therefore,it is of great significance to study and suppress the vibration noise of PMSMs.In this paper,a 12-slot 14-pole PMSM is taken as the prototype to derive the mathematical model of electromagnetic force using the Maxwell stress tensor method and study the modulation effect of electromagnetic force.Based on the modulation effect of electromagnetic force,the vibration noise characteristics of fractional-slot concentrated-windings PMSMs are studied,and the influence of high-order electromagnetic force on vibration noise is emphasized.An improved method of opening auxiliary slots on the surface of the permanent magnet is proposed,and the shape of the auxiliary slot is optimized using response surface methodology to suppress vibration noise while ensuring the output performance of the PMSM.The accuracy of theoretical analysis and finite element simulation analysis is verified through experiments.The main research contents of this paper are as follows:(1)Taking a 12-slot 14-pole PMSM as the prototype,the study of this paper starts from the analysis of the air-gap magnetic field.The air-gap magnetic flux density is solved by using the method of multiplying magnetic potential by magnetic permeability,and the principle of electromagnetic force of the permanent magnet synchronous motor is further studied.The harmonic components of the electromagnetic force are classified and summarized.Then,the modulation effect of electromagnetic force is analyzed,and the process of high-order electromagnetic force being modulated into low-order vibration response is explored.It is demonstrated that high-order electromagnetic force can cause significant vibration noise.(2)Based on the modulation effect of electromagnetic force,this paper analyses the theory of modes,vibration,and noise of PMSM,and further establishes a model of a 12-slot14-pole PMSM.The modal characteristics,vibration,and noise of the 12s-14 p PMSM are analyzed using finite element simulation,which verifies the accuracy of the theoretical analysis.Then,based on the modulation effect of electromagnetic force,the main source of vibration and noise in the prototype is revealed,laying a foundation for the study of vibration and noise reduction methods in the following section.(3)Starting from the permanent magnet magnetomotive force,the vibration and noise reduction principle of permanent magnet slotting is qualitatively analyzed.Then,the response surface optimization method is used to optimize the shape of the auxiliary slots,without affecting the output performance of the motor,thus significantly reducing the vibration and noise of the motor.This paper provides a new approach to suppress high-order electromagnetic forces.(4)An experimental platform for testing the vibration and noise of the 12-slot 14-pole prototype motor is established,and experimental tests are conducted on its modal characteristics,vibration,and noise.The experimental results are compared and analyzed with the finite element simulation results,thus verifying the accuracy of the finite element analysis and noise reduction methods proposed in this paper. |
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