Design And Analysis Of Bipolar Variable Reluctance Brushless Motor

Switched reluctance machines(SRMs)have attracted extensive attentions due to its inherent advantages,including simple structure,low price,high speed operation,and excellent fault-tolerance.However,the existing SRM has the problems of large torque ripple and noise vibration caused by the unipolar current control.In addition,the topology of power converter also limits its application.In this thesis,a new type of variable reluctance brushless motor is proposed,which inherits the advantages of simple structure and strong robustness of the SRMs.The motor can realize bipolar current control by means of effective cooperating relationship between the poles and the teeth and parameter optimization.The universal three-phase full bridge inverter circuit can effectively reduce torque ripple,noise and vibration,and improve power density and efficiency.This thesis first introduces its structure and working principle,then studies its electromagnetic characteristics through finite element simulation software,derives its mathematical model,and finally models and simulates the system through MATLAB/Simulink software,and studies and analyzes the simulation results.The main research contents of this article are as follows:(1)on the basis of not changing the double-salient pole structure of the fixed rotor of the existing switched reluctance motor,a special stacked structure is adopted,and each stack is separately formed into phases.A phase-to-phase independence is proposed and bipolar can be used Brushless AC controlled variable reluctance brushless motor;at the same time,each stack of stator or rotor is staggered by a certain angle to effectively reduce the torque ripple of the motor.The body structure of the motor is fully analyzed,and the working principle of the motor is deeply studied;(2)According to the basic design parameters of the motor,through the ANSYS Maxwell finite element software,two-dimensional finite element simulation modeling of the single stack of the Bipolar Variable Reluctance Brushless Motor,that is,the A phase,and the angle of the motor rotor at different positions and angles The magnetic field distribution and magnetic density line distribution were systematically studied and analyzed.Based on the two-dimensional simulation,the motor is three-dimensionally modeled by Soildworks software,and then imported into the ANSYS Maxwell finite element software,the three-dimensional finite element simulation of the motor is performed,and the results of current,flux linkage and back EMF are analyzed.Then compare the two-dimensional and three-dimensional finite element simulation results,and finally optimize and analyze the motor structure;(3)According to the design parameters and structural characteristics of the motor,the voltage equation and flux linkage equation of the motor are established,and then the electromagnetic torque equation of the motor is derived.Through MATLAB/Simulink,the corresponding module design and modeling simulation of the Bipolar Variable Reluctance Brushless Motor were carried out,each module was analyzed in detail,and the motor torque,current and voltage were systematicalhly studied and analyzed.