| Suspended permanent magnetic levitation train is a new type of low and medium-speed permanent magnetic levitation rail transit system,which is realized by the repulsive force between permanent magnets,linear motor traction and bogie to achieve zero power levitation,train operation and guidance.There are many electrical and electronic devices and strong permanent magnets in the train system.The electromagnetic energy generated by these devices and magnets can interfere with the equipment and instruments on the train and the equipment near the track by radiating or conducting them outward.The standards and electromagnetic field spatial distribution characterization methods for suspended permanent magnet maglev trains are not yet available globally with mature relevant technical standards for reference.Therefore,studying the magnetic field distribution of the suspended permanent magnet maglev train is of great significance.This paper analyzes the magnetic field distribution of suspended permanent magnetic levitation trains by taking the gold “Red Rail” test line of suspended permanent magnetic levitation trains as the research object.Firstly,this paper analyzes the magnetic field of the levitation system composed of strong permanent magnets,and completes the theoretical analysis of the spatial magnetic field distribution of the levitation structure.The electromagnetic simulation model of the levitation system is established in Ansys Electronics Desktop software,and the spatial magnetic field distribution of the single-group and multi-group levitation structures in the levitation system is solved through the stepby-step simplification of the levitation system.The variation trend of magnetic field and magnetic induction intensity at different levitation heights of the levitation system,and the magnetic field distribution area are obtained.The results show that the magnetic field of the levitating structure is characterized by a distribution of large in the middle and small in the sides.With the increase of the train suspension height,the magnetic field strength of the suspension system gradually weakens.In the area where the distance from the suspension structure is greater than 60 mm,the influence of the magnetic field of the suspension system rapidly decreases.Secondly,the magnetic field distribution of the drive traction system composed of a hollow Halbach long-stator permanent magnet synchronous linear motor is studied.The equations of magnetic chain equation and operating current of the motor are calculated by establishing a mathematical model of the permanent magnet synchronous linear motor.The two-dimensional and three-dimensional models of the linear motor are established by Maxwell software,and the magnetic induction intensity of the air gap center under no-load and full-load conditions of the linear motor are calculated by numerical solution.The magnetic field’s change trend in the linear motor’s external space is analyzed.The results show that the electromagnetic field energy generated by the linear motor is mainly concentrated in the direction of motor motion,the magnetic field energy is uniformly distributed.The magnetic induction intensity in the center of the air gap varies periodically in the range of 0-1.1 T,and the radiation range of the magnetic field in the external space of the linear motor is 200～250 mm.With the increase of the distance from the linear motor,the influence of the magnetic field generated by the linear motor gradually weakens.Finally,this paper adopts the magnetic field test system to measure the actual magnetic field of the levitation system and linear motor of the golden “Red Rail” test line.Comparing the test results with the numerical calculation and analysis results,the maximum error of magnetic induction intensity for the levitation system is 9.6%,and the maximum magnetic induction intensity for the linear motor is 10%.The numerical calculation and analysis results are consistent with the experimental results,which verifies the effectiveness of the numerical analysis method for the electromagnetic field of the levitation system and the linear motor.The research in this paper lays the foundation for the development of spatial electromagnetic field characterization methods for suspended permanent magnet maglev trains.It provides a reference for improving the electromagnetic compatibility design of trains. |
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