Analysis Of Electromagnetic Noise And Vibration Of A Permanent Magnet Motor For Electric Car

Permanent magnet motor drive is one of the key components of the BEV,which is related to the vehicle power performance, operability, operation and NVHperformance, while the drive motor vibration and noise problems will seriouslyaffect the ride comfort. The recent research of the motor’s electromagnetic noise isfocus on the asynchronous motor, while the electromagnetic vibration and noise ofpermanent magnet synchronous motor‘s research is comparatively less. In thispaper, the permanent magnet synchronous motor of the pure electric vehicle’s drivemotor vibration and noise is mainly analyzed, the main research content is dividedinto the following several aspects.First of all, in the case of PWM inverter power supply, the pure electricvehicle drive is electromagnetic analyzed by using permanent magnet synchronousmotor. For the machine has the distribution of axial symmetry, in order to simplifythe analysis and calculation, by calculating the motor two-dimensional transientmagnetic field using Ansoft, get the motor magnetic line of force distribution andmagnetic density map, by Fourier of the fundamental and harmonic distributionanalysis to analyze the vibration characteristics of the permanent magnet motor.and figure out the radial air gap flux density. Extract the flux density value, basedon Maxwell’s theorem, using MATLAB calculate the radial electromagnetic forcedensity curve of the motor, on the basis of and the of the motor output torque andmoment are obtained by post-processing features, etc.; And then, starting from thedifferent structure parameters of the motor analysis the influence of differentstructural parameters on the motor electromagnetic field. Thus provides referencefor optimization design of motor electromagnetic vibration.Second, analyze the dynamic characteristics of the whole motor and stator part,namely, the modal analysis. The whole motor natural frequency and vibration modeof the stator and the component diagram are obtained by the finite element modalanalysis, starting from the natural frequency of the motor parts study the vibrationof the motor. Hammering method modal experiment is carried out on a prototype toget the actual low order natural frequency of the motor, compared with the finiteelement analysis results, the two basic consistent, thus proving the reliability offinite element analysis. Finally, this paper uses AWA6291type real-time signal analyzer, on-linemeasure the noise of the pure electric vehicle drive motor, through themeasurement of the motor drive noise under three conditions, work out the motorvibration and noise spectrum, combined with the above research on theelectromagnetic wave, analyzes the reasons of the motor noise in main frequencyband, and provide guidance for the design of motor and noise source identification.