Research On Unbalanced Magnetic Pull,Torque Ripple And Electromagnetic Vibration Suppression Of Permanent Magnet Synchronous Motor With Uneven Tooth(Slot) Pitch For New Energy Vehicles

Permanent magnet synchronous motor has the advantages of high efficiency,high torque density,small size and light weight.With the improvement of high temperature resistance of permanent magnet materials and the reduction of price,permanent magnet motors are used in aerospace,rail transportation,electric vehicles and other fields It has been widely used.However,the permanent magnet motor has two prominent problems:the cogging torque and the tooth harmonic electromotive force component are large,which causes the increase of the motor torque ripple and vibration noise,which affects the efficiency and output quality of the motor.These disadvantages of the permanent magnet motor Limit its wide application.This paper studies a kind of non-uniform tooth(slot)pitch permanent magnet synchronous motor for new energy vehicles,that is,unequal tooth width combined permanent magnet synchronous motor and unequal slot width combined permanent magnet synchronous motor,which can solve the above problems.This article describes the existing methods of weakening torque ripple and electromagnetic vibration,studies a new type of unequal tooth(groove)width combined permanent magnet synchronous motor,introduces the structure characteristics of the motor and weakens cogging torque and tooth harmonics The principle of wave was established and simulated by finite element software.The cogging torque,back electromotive force,output torque and unbalanced radial magnetic pulling force of the motor were analyzed,and the performance characteristics of the motor were fully demonstrated.This paper analyzes the principle of avoiding the generation of unbalanced radial magnetic pulling force in the new type of unequal tooth(slot)width combined permanent magnet synchronous motor,gives the design method to avoid the generation of unbalanced radial magnetic pulling force,and uses the finite element software for calculation.The effectiveness of this method is proved.In this paper,the formula of the cogging torque of the motor is derived,and the source of the cogging torque is analyzed in combination with the specific parameters of the motor such as the number of slots,the number of poles,and the number of wide stator teeth(slots).This paper focuses on the analysis of the weakening effect of the change of the number of wide stator teeth(slots)on the cogging torque,and gives the method of selecting the number of wide stator teeth(slots)at any number of poles.The calculation results of the finite element software prove,Through analytical calculation to select the appropriate number of wide stator teeth(slots)and the ratio of wide stator teeth(slots)to narrow stator teeth(slots)width,can significantly reduce the cogging torque of the permanent magnet motor,thereby weakening the motor rotation Moment pulsation and electromagnetic vibration.In this paper,the expression of the synthetic magnetomotive force of the motor with a combination structure of unequal tooth(slot)width is derived.The influence of different armature winding winding methods on the synthetic magnetomotive force is analyzed.The optimal armature can be determined by analytical calculation The winding method is used to improve the torque density of the motor,and the calculation using finite element software proves the effectiveness of the method.This paper compares the performance of the proposed new unequal tooth(slot)width combined permanent magnet synchronous motor.The comparison results show that the new motor has good performance.