Research On The Design Method Of Low-noise Permanent Magnet Synchronous Motor

The electromagnetic noise of permanent magnet synchronous motors is one of the important problems to be solved urgently in the design and application of motors.This dissertation focuses on the suppression of electromagnetic vibration noise caused by magnetostriction and the design of low-noise permanent magnet synchronous motors.First of all,this dissertation combines the secondary domain transfer model,analyzes the electromagnetic and mechanical fields on the stator of the permanent magnet motor,and establishes a numerical model of electromagnetic-mechanical coupling.The simulation calculation of the motor stator found that the low-frequency noise of the motor occurred near the double frequency and the double frequency of the power supply frequency.The corresponding experiments were designed and found to be consistent with the simulation results,which verified the correctness of the model.Secondly,for the vibration force wave at the frequency of double the power supply,with the help of the simulation model,the influence of the silicon steel sheet specification,the number of laminated sheets,the coil,and the relative position on the vibration of the motor is analyzed.The deflection of the magnetic circuit causes the silicon steel sheet to generate a double frequency vibration.Different conditions affect the main frequency and amplitude of the vibration,and the vibration is particularly significant at the double frequency.An experiment was designed to measure the vibration signal on a silicon steel sheet under a changing magnetic field,and the simulation results were verified.Finally,the motor stator is simulated and calculated.It is found that the magnetic density at the top and root of the stator teeth is relatively concentrated,the magnetic circuit deflection is large,and the stress is mainly concentrated in the magnetic circuit distortion area.To suppress the vibration noise of the motor caused by the magnetostrictive effect,the stator of the motor is designed to be filled with negative magnetostrictive material.By changing the position,radius,and several holes,the best drilling scheme to reduce noise is found.