In Electrodynamic Suspension (EDS) system, the lack of levitation force is an important factor restricting the take-off speed. The structure of 8-figure ground coil affects the performance of levitation and guidance. It is an important task to design a new type of 8-figure coil to reduce the take-off speed of EDS Maglev. In this paper, the characteristics of figure 8 coil with different upper and lower coil heights are studied, and the equivalent circuit model of asymmetric figure 8 coil is established based on the dynamic circuit theory. By determining the interaction between the figure 8 coil and the moving Superconducting Magnet (SCM), parameters such as levitation force, guidance force, drag-to-lift ratio are calculated. The variation of levitation force and guidance force under different type of asymmetric figure 8 coil was compared, and the influence of the asymmetry degree of figure 8 coil on the train floating height is analyzed. The results show that the asymmetric structure can improve the floating height and reduce the take-off speed of EDS train, but weaken the guiding force. By comparing the analytical calculation of the dynamic circuit model with the simulation results of 3D finite element method (FEM), the calculation error is less than 10%, which verifies the validity of the analytical model.

EDS maglev;dynamic circuit theory;asymmetric 8-Figure coils;electromagnetic force