Research On Electromagnetic Vibration Of Permanent Magnet Synchronous Motors

With the development of industry,the motor as an electromechanical energy conversion and signal conversion of the electromagnetic mechanism,has been widely used in various fields of national economy and daily life,bringing great convenience to our life.At the same time,it also brings serious noise pollution,the electromagnetic noise is the main component of the motor vibration noise,and the magnetostrictive effect is an important factor that causes electromagnetic vibration.Therefore,it is of great significance to explore the electromagnetic vibration caused by magnetostriction.In order to explore the effect of magnetostrictive effect on electromagnetic vibration,in this thesis,the magnetization properties and magnetostrictive properties of 50WW470 non-oriented silicon steel sheet are measured by measured equipment from BROCKHAUS,Germany.And the magnetization curve and magnetostrictive single value curve are obtained,which can be used to study the electromagnetic vibration of permanent magnet synchronous motor.Based on the Maxwell's equations and the basic theory of elasticity,COMSOL Multiphysics multi-physics coupling analysis software is used to establish electromagnetic-machine coupled numerical model considering the magnetostrictive effect.Compared with the only consideration of the effect of electromagnetic force,the stress distribution of motor stator at different times under the joint action of magnetostrictive force and electromagnetic force is calculated,as well as the stator core time-domain and frequency-domain responses under different supply frequencies.And the corresponding experiment is carried out to verify the correctness of the model.In view of the fact that the vibration at the supply frequency is stronger than the double supply power frequency,the experiment of coils,coils and silicon steel sheets in different positions are designed.The coil and silicon steel sheet are separated,and the vibration of a point on the coil and silicon steel sheet is measured and analyzed,and the cause of the one-frequency force is analyzed.And according to different experiments,the corresponding finite element modelings are carried out.The electromagnetic force at a point on the coil and the magnetostrictive force at the point on the silicon steel are numerically calculated.It is found that when the silicon steel plate is perpendicular to the bottom of the coil,the main vibration frequency of the magnetostrictive force is the power supply frequency.The numerical results are verified by comparing the experimental results with the finite element simulation results.