Calculation And Analysis Of Vibration And Noise Of High Speed Permanent Magnet Synchronous Motor

In recent years,with the rapid development of machinery manufacturing industry,permanent magnet synchronous motor has been applied in various fields.Compared with the traditional motor,the high-speed permanent magnet synchronous motor has outstanding advantages,but the problem of vibration and noise hinders its application in some fields.Therefore,the noise reduction of motor has become a hot spot in the field of motor research,and the competitiveness of low-noise motor in the market is becoming more and more advantageous.There are three main ways to generate vibration and noise of high-speed permanent magnet synchronous motor: electromagnetic force,mechanical vibration and air vibration,but because of its complexity,electromagnetic noise has become the focus of domestic and foreign scholars.The problem of electromagnetic vibration and noise of high-speed permanent magnet synchronous motor is quite prominent.There are two reasons: first,the harmonic of radial electromagnetic force generated by air gap magnetic field is relatively complex;second,when the natural frequencies of each stage of the motor are close to or equal to the time frequency,it will lead to structural resonance,that is,a very small frequency will also cause huge noise.In this paper,a 15 kW,30000r/min,4pole,18 slot high-speed permanent magnet synchronous motor is taken as the research object.Combined with the electromagnetic mechanics,structural dynamics and acoustic theory,the analytical method and finite element method are used to carry out the following research:Firstly,the electromagnetic force wave of high-speed permanent magnet synchronous motor is studied.In this paper,the order and frequency of the electromagnetic force on the inner surface of the stator teeth of the motor are analyzed theoretically by using the analytical calculation method,and the analytical calculation is verified by the two-dimensional field finite element simulation,so as to determine the harmonic frequency and frequency of the electromagnetic force on the motor.Secondly,the structural modal analysis of high-speed PMSM is carried out.The finite element method and the mechanical impedance theory are used to calculate and analyze the inherent modes of the stator,the stator system and the whole machine,and the influences of the different thickness of the shell and the end cover on the inherent modes of the motor are studied.In order to verify the reliability of the design of the high-speed permanent magnet synchronous motor,the experiment is carried out.Finally,the influence factors of vibration and noise of high-speed PMSM are analyzed.The effects of air gap length,pole arc coefficient and slot width on vibration and noise of PMSM are analyzed,and the effective methods and suggestions for vibration and noise reduction are put forward.The influence of different driving modes on motor vibration and noise is analyzed.