| With the continuous maturity of maglev technology,the speed requirements for maglev trains used in rail transit are also increasing.Permanent magnet electric levitation technology has become one of the research hotspots of high-speed maglev due to its advantages of good self-stability and simple structure.At present,the research of permanent magnet electric suspension technology mainly focuses on the optimization and suspension stability of the Halbach permanent magnet array,and certain progress has been made.However,the research on the processing method of the magnetic-track relationship and the dynamic model including the multi-body structure of the system is still very lacking,which is not enough to promote the research and development of the permanent magnet electric suspension system.Therefore,it is imperative to carry out its modeling method research and dynamic performance analysis.This thesis takes a permanent magnet electric suspension system as the research object.According to its working principle and structural characteristics,the magnetic field distribution characteristics of the Halbach array are obtained through theoretical analysis and finite element simulation.The relationship between the magnetic force of the system and the speed and the gap is clarified,and a look-up table method is proposed to solve the nonlinear magnetic orbit relationship of the Halbach array.Using SIMPACK software,the dynamic simulation model including the multi-body structure of the system is established,and the dynamic response of the system under different working conditions is analyzed.The main work of this thesis is as follows:(1)The main structure and working principle of permanent magnet electric suspension system are expounded.The finite element simulation model of Halbach permanent magnet array is established,and its magnetic field and magnetic force are simulated and analyzed.The results show that the Halbach permanent magnet array has the characteristic of unilateral magnetic field strengthening.The suspension force and magnetic resistance decrease exponentially with the increase of clearance.With the increase of velocity,the levitation force increases but the growth rate decreases gradually,and the magnetic resistance firstly increases rapidly and reaches its peak at about 15 km/h,then decreases continuously and approaches zero.(2)According to the magnetic characteristics of the Halbach array,a look-up table method is proposed to establish the magnetic-track interaction relationship of the permanent magnet electric suspension system.The magnetic force at the key nodes is obtained through finite element simulation,and the difference calculation is used for reference to the surface integral idea and limit theory to obtain the magnetic force at different positions in the middle.Combined with the structure of the permanent magnet electric suspension system,a dynamic simulation model is established by using SIMPACK software.By comparing the variation trend of the natural frequency of the frame and the frequency size of different nodes under theoretical derivation and dynamic simulation,the correctness of the magneto-rail relationship treatment and dynamic model of permanent magnet electric suspension is verified.(3)Based on the dynamic model,the necessity of installing the damping device in the permanent magnet electric suspension system is studied.The arrangement positions of the suspension module and the damping module are optimized,and the results show that the system dynamic performance is optimal when the longitudinal position of the suspension module is 0.92 m and the longitudinal position of the damping module is 0.15 m.Taking the maximum and minimum values of the suspension gap as the control objectives,the sensitive wavelength and amplitude of the system are analyzed.The suspension sensitive wavelengths of the obtained system are less than 1.8 m,10～16.54 m,18.38～27.58 m,and the roughness sensitive amplitude is greater than 6 mm. |
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