Research On Thrust And Saturation Effect Of Oriented Silicon Steel Sheet Permanent Magnet Linear Synchronous Motor

Permanent magnet linear synchronous motor(PMLSM)has been applied in many fields due to its zero transmission and special structure.Combined with the magnetic circuit characteristics of PMLSM,the application of oriented silicon steel sheet to the primary core of PMLSM is proposed.By using the characteristics of high magnetic permeability in the direction of rolling of oriented silicon steel sheet,the magnetic density of PMLSM is improved,and the thrust density is improved and the saturation effect is improved.In this thesis,the thrust performance and saturation effect of non-oriented silicon steel sheet and oriented silicon steel sheet PMLSM are taken as the core,and the end force ripple unique to linear motors are studied,and weakening measures are taken.The main work of this thesis is as follows:Firstly,the expression of electromagnetic thrust of PMLSM is analyzed theoretically,and the expression of the end force of linear motor is derived.The finite element method is used to verify the results.The results show that the period of end force is the polar distance τ.Combined with the periodic variation of the end force,this thesis weakens the end force of the motor by magnet segmentation skew pole.The finite element method is used to obtain the thrust ripple of PMLSM after different segmentation number skew pole,which indicates that the segmentation skew pole can effectively reduce the thrust ripple of PMLSM.Secondly,after applying oriented silicon steel sheet,the thrust of PMLSM is improved by 4.6%.The influence of oriented silicon steel sheet on the thrust of PMLSM is studied from the aspect of changing the magnetic circuit structure and magnetic circuit saturation of the motor.In terms of the magnetic circuit structure,the tooth-yoke ratio of the motor is changed by changing the length of the tooth magnetic circuit and keeping the length of the yoke magnetic circuit,thereby improving the utilization ratio of the oriented silicon steel sheet.In terms of magnetic circuit saturation,the thrust performance of oriented silicon steel sheet and non-oriented silicon steel sheet PMLSM is compared and analyzed by increasing the armature current of the motor.Finally,the influence of the saturation effect of the magnetic circuit on the inductance parameters is analyzed.The inductance calculation method of the salient pole motor model and the no-salient pole motor model is derived theoretically,and the inductance matrix of the motor is transformed into the dq-axis inductance according to the principle of coordinate transformation.After increasing the tooth-yoke ratio of the motor,the oriented silicon steel sheet motor has a lower degree of saturation,so the oriented silicon steel sheet motor has a higher advantage in the similar number of poles and slots motor.Improve the saturation of the motor by increasing the armature current of the motor.The results show that the oriented silicon steel sheet can effectively reduce the saturation degree of the motor,and the higher the magnetic saturation of the motor,the more obvious the advantages of the oriented silicon steel sheet.