Research On Optimization Of Stator Shape In Switched Reluctance Motor Based On The Reduction Of Torque Ripple And Radial Force

With the development of power electronics and microelectronics technology,the Switched Reluctance Motor(SRM)has been further developed.SRM is widely used in textile machinery,mining machinery and electrical vehicles because of its simple and robust structure,low manufacturing cost,good fault tolerance,high efficiency,good regulation-speed performance and convenient maintenance.However,due to its inherent doubly salient structure and frequent turn-on and turn-off power supply,the vibration and noise of SRM is high,which limits its application in the field of strict requirements for noise and vibration.Therefore,how to reduce the vibration and decrease the noise of SRM has become the focus of research,which is of great research significance.First of all,the methods of reducing SRM torque ripple and radial force at home and abroad is analyzed and summarized,the basic structure and working principle for SRM is interpreted,and the electromagnetic characteristics is given.Furtherly,the reason of vibration is analyzed,and it is clear that the electromagnetic force in the radial direction and the torque ripple in the tangent direction produce the motor vibration.Secondly,considering the edge effect of flux at the salient pole,the relationship among the magnetic conductivity,flux and torque is clarified.In order to reduce torque ripple,the equivalent magnetic circuit(EMC)method is used to prove that increasing the edge magnetic conductivity can effectively improve the minimum torque.The edge magnetic conductivity is improved by adding pole shoes on the four phase 8/6 pole motor model in front of the stator rotation direction.The several groups data with different pole shoe sizes,including flux,average torque and torque ripple,are compared by finite element analysis.The model size with smaller torque ripple is selected without reducing the average torque.Thirdly,in order to reduce the radial force,it is clear that slotting at the top of stator pole can reduce the peak value of radial force wave based on the theory of Maxwell stress tensor.The influence of slot size on average torque,torque ripple,radial force,peak value of radial force wave and air gap magnetic density in tangential and radial direction is analyzed.The results show that the model can reduce the radial force and the peak value of radial force wave.Finally,the natural frequency of the model is determined by modal analysis,Maxwell electromagnetic force is coupled to Workbench for harmonic response analysis,and the motor noise is simulated and analyzed,which further verifies the reliability of the theory.According to the parameters of the motor,the prototype is made,and the experimental platform is set up.The vibration acceleration of the motor is measured by using the vibration acceleration sensor,data acquisition card and other equipment to complete the verification of the prototype.