| Magnetic levitation technology uses magnetic field force to separate the suspension body from the support body,and has no mechanical contact with each other.It has a series of advantages,such as low friction resistance,no mechanical wear,low noise and long life.It has been widely used in magnetic levitation train,magnetic bearing and magnetic suspension platform.Aiming at the shortage of high cost and high energy consumption in long-range maglev transport system,a novel detent-force-based magnet suspension support system is proposed.The key technical problems such as working mechanism,innovative structure,electromagnetic characteristics and performance optimization,and air gap control method are studied.The main research contents are as follows:A novel detent-force-based magnet suspension support system has the advantages of no permanent magnet on the stator side,high suspension force,low cost and simple structure.The topological structure and working principle of suspension platform are introduced in detail.By comparing and analyzing the air gap magnetic density and suspension force characteristics of ordinary permanent magnet structure,convex iron permanent magnet structure,Halbach permanent magnet structure,rectangular permanent magnet structure and U permanent magnet structure suspension module,the structure of convex iron structure,track yoke iron structure and permanent magnet magnetization direction affecting suspension performance are analyzed,and the structure of U suspension module can be preliminarily determined.The equivalent magnetic network model is established according to the magnetic field distribution of the suspension module,and the constraint relation expression between the suspension force and the structural parameters of the suspension module is derived by the virtual displacement method,and the suspension force under different air gap length and vertical displacement is calculated,which is compared with the finite element results to verify the accuracy of the analytical results.The characteristics of suspension force,lateral force,stiffness of suspension module and dynamic eddy current damping are analyzed,and the relationship curves between structural parameters and suspension force,lateral force,permanent magnet,rail yoke iron,suspension module stiffness and parameters are analyzed.The influence of structure parameters,air gap magnetic field and running speed on eddy current damping characteristics is discussed.Based on the optimization design method of Taguchi parameters,a multi-objective optimization design of the suspension module is carried out.The optimization targets are selected,such as suspension force,permanent magnet volume and rail yoke iron cross-sectional area,the optimization parameters and the range of values are determined and the experimental orthogonal matrix is established.The finite element method is used to solve the experimental matrix,and the specific gravity of each optimization parameter on the performance of the suspension module is analyzed.The results before and after optimization are compared and analyzed,and the results show that The optimized amount of permanent magnet and the amount of rail yoke iron have been reduced,and the suspension force has been greatly improved under the same amount of permanent magnet.The suspension force and air gap magnetic density of U type permanent magnet structure and U type permanent magnet structure are compared and analyzed.The air gap magnetic density and suspension force of U type permanent magnet structure suspension module are reduced,but the thickness of yoke is reduced and the flexibility of permanent magnet design and installation is increased.The electromagnetic characteristics of the suspension module of the U type permanent magnet structure are analyzed by using the finite element method,and the parameter combination which can make the suspension module of the U permanent magnet structure obtain the maximum suspension force is determined.The optimized yoke of the U permanent magnet structure is obtained by the mesh method,which reduces the amount of the ferromagnetic material and keeps the size of the optimized.To solve the problem of lateral disturbance in a DMSP,a lateral air-gap balance controller is designed.The static and dynamic model of the controller is established.The fuzzy adaptive PID control system is designed and verified by Matlab/Simulink software.The results show that the fuzzy adaptive PID controller has the advantages of fast response speed and strong robustness. |
