Research On The Characteristics And Application Feasibility Of Ultra-high-speed Maglev Eddy Current Braking System

The rapid development of super high speed maglev has put forward higher requirements for its braking performance.In recent years,eddy-current braking has been widely used in maglev braking due to its advantages of good controllability,no pollution and no contact between vehicle body and rail.Based on the research background of super high speed maglev,this thesis focuses on the characteristics of eddy-current braking force in maglev eddy-current braking system,and then analyses the feasibility of applying eddy-current braking system in super high speed maglev.The eddy-current brake system is modeled and analyzed.The sub-domain method and the electromagnetic field equation are combined to calculate the magnetic field in each subdomain and the eddy-current braking force of the electro-exciting eddy-current braking system respectively under the condition of neglecting the skin effect in the induction plate and considering the skin effect in the induction plate.The accuracy of the analytical calculation of these two cases is verified by finite-element simulation.The performance of eddy-current braking force is analyzed and optimized.According to the analytical formula of braking force without the skin effect of the induction plate,the relationship between parameters and the braking force is analyzed by using the control variable method;In addition,according to the braking analytic formula considering skin effect of induction plate,the parameters of two key factors affecting the performance of eddy-current braking force,peak braking force and its corresponding speed point(referred to as critical velocity)are analyzed.Thus,the methods to improve the eddy-current braking force performance of the maglev at high and super high speeds are obtained.The feasibility of applying eddy-current brake system to super high speed maglev is studied.According to the requirement of magnetic levitation test project,the operation condition of magnetic levitation skid is calculated and analyzed,and the feasibility of applying eddy-current braking system to magnetic levitation skid at high speed and super high speed is demonstrated.The basic design of the rotating eddy-current brake experiment platform is realized.Combined with the equivalent magnetic circuit method,the electromagnetic design of the rotating eddy-current braking experimental platform is carried out according to the parameters of analytical calculation model and finite-element simulation model,and the processing technology of the experimental platform is considered to complete the design of the structural scheme.The experimental platform has the advantages of adjustable speed,adjustable air-gap length and replaceable rotor induction plate.It can complete the verification of analytical calculation and finite-element simulation.This research can provide important guidance for the application of eddy-current braking system in super high speed maglev and the improvement of the performance of eddycurrent braking system.