Research On Equivalent Magnetic Network Method And Vibration Noise Analysis Of Permanent Magnet Synchronous Reluctance Motor

With the continuous development of permanent magnet motor,the permanent magnet synchronous reluctance motor(PMSRM),which combines permanent magnet synchronous motor with synchronous reluctance motor,has gradually appeared in various fields of motor industry.It not only has the advantages of high torque density,high power density and high power factor of the former,but also has the characteristics of low manufacturing cost of the latter.However,the structure of PMSRM,such as irregular magnetic barrier and permanent magnet,makes the design process of the motor more complicated,and also has the problem of high vibration noise which needs to be solved.As an analytical method for the early optimization design of motor,the equivalent magnetic network method(EMNM)is superior to the traditional magnetic circuit method in the calculation accuracy,and superior to the finite element method(FEM)in the calculation speed.In this paper,a 5.5k W,1500r/min 4-pole PMSRM is taken as the research object.The EMNM is used to design the motor parameterization,which can save a lot of time and work for the motor design.Combined with the FEM,the vibration and noise characteristics of the optimized scheme are analyzed and studied as follows:Firstly,the principle of EMNM is introduced,and the complex structures such as magnetic barriers,permanent magnets and stator slots in the PMSRM are reduced to multi-layer fan annular structures.After verifying the rationality of the simplification by FEM,the PMSRM is divided and the equivalent magnetic conductivity and equivalent magnetic potential source are calculated.The EMNM model of PMSRM considering magnetic saturation state is established by nonlinear fitting method.The simulation program is written according to the programming software,and the accuracy of the EMNM model is verified by comparing the no-load air gap magnetic density,air gap harmonics,radial electromagnetic force and space harmonics with the FEM.Secondly,the rotor structure of PMSRM is parameterized by using the established EMNM model,which saves a lot of time for the early design of the motor.Respectively study one-type and U-type permanent magnet in magnetic barrier width,permanent magnet thickness,one-type and the stator magnetic barrier width slit width of structural parameters,such as motor no-load air gap flux density,air gap,waveform distortion rate,and part of the solution of FEM calculation salient rates,the influence of rotor structure to select from a variety of solutions to meet the requirements.Finally,the vibration noise of the optimized PMSRM is analyzed by using the FEM software.The mode of stator and the whole motor are analyzed respectively,and the natural frequencies of each mode of the motor in the two systems are calculated to avoid the resonance phenomenon of the motor during operation.The radial electromagnetic force simulation and vibration and noise simulation of PMSRM in time domain are coupled to analyze the vibration displacement,vibration acceleration and noise sound pressure level of the motor.The validity of the optimization scheme is verified by motor vibration experiment.