Research On Ferrite Permanent Magnet Synchronous Servo Motor With Concentrated Winding

Permanent magnet synchronous motors have a wide range of applications due to their high power density in various high-efficiency motors.Ferrite permanent magnet synchronous reluctance motors have become a research focus because of their low cost and good sustainability.At present,the main research direction is high-power distributed winding motors,and concentrated winding motors are rarely researched.The concentrated winding motor has the advantages of short end,low copper consumption,high full tank rate,strong fault tolerance,and simple embedded wire technology.However,it can not use short-distance winding to reduce harmonics and has poor electromagnetic performance.This paper studies the application of ferrite concentrated winding motor in low power servo system.This article first investigated the domestic development and research status of the ferrite permanent magnet synchronous reluctance motor,servo motor torque characteristics optimization,electromagnetic vibration and noise,proposed the research purpose and significance of this article,and introduced the work arrangement of this paper.Then the design requirements of the ferrite concentrated winding servo motor are proposed.The basic dimensions of the motor are obtained by using the electromagnetic design formula of the motor and finite element optimization simulation.In order to reduce the harmonics of the concentrated windings,a comparative analysis of the electromagnetic performance of the three types of slots has been obtained with better slot coordination,based on the combination of the complex structure of the rotor structure of the ferrite motor,the number of rotor magnetic steel layers,The optimization of magnetic angle and interlayer distance has greatly reduced the servo motor torque ripple.Analyzed and deduced that the magnetic pole offset can reduce the cogging torque of the motor,using the finite element scanning simulation method to obtain the optimal magnetic pole deflection angle.From the aspects of torque performance,demagnetization characteristics,and cost performance,the concentrated and distributed windings of ferrite were comparatively analyzed.It was concluded that concentrated windings are more suitable for the field of low-power servo motors.Subsequently,the stator modes of the concentrated winding motor are analyzed to obtain modal frequencies of different orders.The spatial radial force waves of the concentrated windings are analyzed,and it is found that they contain pole pairs of low-order radial force waves,which is the cause of large electromagnetic vibration in concentrated winding motors.The influence of magnetic angles and magnetic pole deflection angles on the low-order radial force waves under both no-load and load conditions is studied,which has guiding significance for reducing the electromagnetic vibration and noise of concentrated winding motors.The electromagnetic vibration and noise characteristics of concentrated windings and distributed windings are compared and analyzed.Under different operating conditions,the concentrated windings have large electromagnetic vibration accelerations,but their noise is small.Finally,based on the previous research results,a 1.5kw ferrite servo motor prototype was made,and the prototype was subjected to no-load back-EMF experiments,cogging torque measurement experiments,modal experiments,and the experimental results were compared with the simulation results.The analysis verifies the correctness of the finite element simulation method and the reliability of the analysis results.