Design Of Hybrid Excitation Linear Maglev Synchronous Motor

In this thesis,a hybrid excitation linear maglev synchronous motor(HELMSM)is designed as a feed drive device for NC machine tools.Compared with the traditional feed method,this feed method has the advantages of direct suspension,zero friction and large floating air gap.The device reduces the manufacturing difficulty of the platform and improves the economy and reliability of the system.This motor has very important research significance for high precision and high speed NC machine tool machining.The main contents of the thesis are as follows:(1)Structural design of hybrid excitation linear maglev synchronous motor.According to the special structure of the linear motor,the basic size design formula of the linear motor is deduced.Determine the design of the transverse and longitudinal length of the motor,the stator of the motor,the pole slot fit,the armature winding and the material and size of the permanent magnet.The design steps of the motor are summarized,and the equivalent magnetic circuit of the motor is calculated and analyzed.(2)The structure of a new hybrid excitation linear maglev synchronous motor is presented.Based on the analysis of the existing hybrid excitation structures,the hybrid excitation linear magnetic levitation motors with different topologies are built.A new structure motor model is presented.The air gap magnetic field of six motors with different structures is compared and analyzed,and the sine degree of the air gap flux density waveform is analyzed.Then,the electromagnetic thrust and suspension force of the six models are compared to verify the superiority of the new structure.(3)Finite element analysis of hybrid excitation linear maglev synchronous motor.The two-dimensional finite element model of the hybrid excitation linear maglev motor was established,the magnetic field distribution of the motor in no-load state and load state was obtained,and the harmonic content of the air gap magnetic-density waveform was analyzed.Then,the effects of different permanent magnet thickness,air gap length,excitation current and different armature current on the electromagnetic thrust and levitation force of the motor are research.The rationality of the hybrid excitation linear magnetic levitation motor is verified,which lays a foundation for further analysis of the hybrid excitation linear magnetic levitation motor.Finally,the three-dimensional model of the hybrid excitation linear maglev synchronous motor is established,and the finite element calculation of the motor is carried out to analyze the similarities and differences between the three-dimensional model and the two-dimensional model,so as to further study the rationality of the structural design of the motor.(4)Study the mathematical model and magnetic field coupling analysis of hybrid excitation linear maglev synchronous motor.The expressions of the electromagnetic thrust and suspension force of the motor are derived,and the decoupling control of the suspension system and the horizontal feed system is carried out by using i_d=0 for field orientation control.At last,the Matlab/Simulink model of the hybrid excitation linear maglev synchronous motor is built,and the starting and coupling of the motor with load are studied.