Vehicle-track coupled dynamics model for superconducting electrodynamic suspension train

In the previous studies of superconducting EDS train, the magneto-electric coupling between superconducting magnets (SCMs) and null-flux coils (NFCs), was equivalent to a vibration system with constant stiffness. This premise has decoupled the magnetic/track interaction and is not able to study the dynamics issues in an accurate and comprehensive level. Therefore, the vehicle-track coupled dynamics model of superconducting EDS train, with magneto-electric-force coupling fully considered, was established to explore the vehicle-track interaction relationship in this paper. A mathematical model based on Newton's laws and 3-D dynamic co-simulation model were built respectively by Simulink and MATLAB-SIMPACK to compare the operating performances with the time/frequency domain. Meanwhile, the dynamic electromagnetic forces were calculated by dynamic circuit theory rather than merely assuming the constant stiffness. The dynamic responses of suspension vehicle show that, the vibration of carbody and frame are mainly concentrated about 1 Hz and 5 Hz respectively. The use of equivalent model in the previous studies has overestimated the negotiation capacity of superconducting EDS train. Furthermore, the vertical vibration accelerations of frame in the coupled model are relatively larger, whereas the lateral vibration is comparatively smaller. Therefore, the electromagnetic calculation of superconducting EDS train with constant stiffness overestimates/underestimates the dynamic performances.