Mathematical Modeling And Control Of Large Air Gap Hybrid Maglev Structure

Maglev technology has the advantages of no friction,no loss,low energy consumption,no noise,long life and so on.Because magnetic force is used as the supporting force,accurate calculation of magnetic force will play a vital role in the theoretical and applied research of maglev technology.Magnetic circuit method is widely used in engineering to calculate the supporting magnetic force,and its theoretical basis is the uniform distribution of air gap magnetic field,no magnetic leakage,magnetic material linear unsaturated,etc.However,this method is not applicable to the large air gap maglev structure,uneven distribution of large air gap maglev structure have spirit gap magnetic field,magnetic flux leakage increase sharply,working point range,shortcomings and so on nonlinear strong magnetic field,its magnetic modeling difficulty,accuracy is not accurate,so need to modify based on magnetic circuit method or create a new design method.In order to solve this kind of large air gap hybrid maglev structure modeling is not accurate,this thesis is based on the distribution of air gap flux and magnetic force lines of the permanent magnet in the maglev structure,the magnetic circuit model is established by using magnetic field splitting method and equivalent magnetic circuit method,and the magnetic force mathematical model of large air gap maglev structure is established by combining the characteristics of magnetic materials and electromagnetic field theory.In this thesis,detailed theoretical analysis and finite element analysis are carried out on the mechanical properties of the hybrid maglev structure with large air gap,as well as the recording and analysis of experimental data.In terms of mechanical properties,the influences of radial displacement and axial air gap on radial permanent magnetic force and axial permanent magnetic force are obtained by comparison.The influence of coil current of electromagnet and distance of permanent magnet suspended object on radial electromagnetic force is analyzed,and the validity of mathematical model of permanent magnetic force and electromagnetic force is verified.Finally,the nonlinear robust controller is designed according to the magnetic force mathematical model of the large air gap maglev structure,so that the system can finally have relatively accurate and stable control ability with the mathematical model under the condition of maximum uncertainty,and the simulation verification is carried out.The results show that the designed nonlinear robust controller has good disturbance suppression ability and certain energy saving effect,and can realize the stability of the system.