3D Magnet-Rail Relationship And Its Application In Dynamics Of Middle And Low Speed Maglev Train

Characteristics in suspension and guidance process is the key of research on maglev train.Maglev train achieve suspension and guidance through the electromagnetic force generated between rail and the pole-face of electromagnet.The effects of the current in the coil,the material properties of the magnet medium,and the relative poses of the electromagnet and rail in the presence of electromagnetic force are referred to as the magnet-rail relationship,which is the foundation of dynamic research of maglev train.And it is important to establish an accurate magnet-rail relationship model to carry out dynamic research of maglev train.After reviewing all existing research advancement,this paper establish a meta-model of magnet-rail relationship with considering of the current in the coil,the magnet saturation,and the relative poses of the electromagnet and rail,using the method of uniform design,computer experiments,and stepwise regression.In addition,the influence of 3D magnet-rail relationship on dynamic characteristics of maglev train was analyzed.The main research contents and innovation are as follows:1.Develop a method to model magnet-rail relationship and evaluate it,based on uniform design,stepwise regression,leave-one-out cross-validation and case validation at untried points.2.Based on the method described above,according to the design parameters and features of middle-low speed maglev train,meta-models of 2D magnet-rail relationship was established to calculate the levitation and guidance force.Evaluation results show that the obtained meta-models of 2D magnet-rail relationship can predict electromagnetic force value more accurately when the magnetic medium was in saturation states,compared with existing analytical 2D magnet-rail relationship.3.Based on the same scheme,meta-models of 3D magnet-rail relationship were established with considering magnetic saturation and the spatial relative poses between rail and electromagnet,and the levitation force,guidance force,pitch torque,yaw torque and roll torque can thus be calculated.Evaluation results show that the obtained meta-models of 3D magnet-rail relationship can predict electromagnet force more accurately with consideration of spatial relative motion.4.Based on the meta-model of 3D magnet-rail relationship,dynamic simulation of maglev train with 5 bogies was carried out,and characteristics from the meta-model and existing analytical formula were compared.It is shown that the dynamic characteristics of maglev train varies obviously versus magnet-rail relationship,both in suspension process and under the excitation of irregularity.To sum up,magnetic saturation and spatial relative motion have obvious influence on magnet-rail relationship,thus on the dynamic characteristics of maglev train and stability of suspension control system,which was shown by this paper’s results.Therefore,this paper’s work is of great significance to carry out research work on dynamics of maglev train,suspension control algorithm,and especially on stability of suspension control system when magnetic medium was near its saturation states.