Characteristics of the Linear Motor for Electrified High-Speed Maglev Transportation in the Rotational Motions Caused by Asymmetry Transverse Air-Gaps

The electromagnetic characteristics and running stability of the linear motor for electrified Maglev transportation under rotational motions caused by asymmetry transverse air-gaps are calculated and analyzed. First, considering the end effect and the shape of the vehicle coils, the formulas of levitation and guidance currents, levitation and guidance forces, rolling torque, yawing torque, coupling stiffness between lateral and rolling direction, coupling stiffness between lateral and yawing direction, and equivalent guidance stiffness are derived. Second, the variations of rolling torque, yawing torque, guidance force, and levitation force with different lateral displacement, rolling angle, and yawing angle are predicted. Then, the two coupling stiffnesses and the equivalent guidance stiffness at different operating speeds are investigated. Finally, in order to verify the analysis results, not only the three-dimensional (3-D) finite-element method (FEM) model is established but also the experiments are carried out. It shows that the combined levitation and guidance electrodynamic suspension (EDS) maglev train will roll and yaw, and its levitation height also changes after being disturbed laterally. In addition, the train will run more stably when being disturbed laterally as running speed increases.