Modeling and Characteristic Analysis of Air-Cored Linear Synchronous Motors With Racetrack Coils for Electrodynamic Suspension Train

Air-cored linear synchronous motor (LSM) consisting of racetrack coils is a core part of electrodynamic suspension (EDS) as it propels train to realize high-speed running. Considering operating conditions, a precise and fast analysis of LSM is essential to investigate and optimize EDS system. An analytical model is proposed to calculate the magnetic field and 3-D forces of LSM with considering the sectional power supply of the primary and multi-degree-of-freedom (DOF) motions of EDS train. Afterward, the influence of sectional power supply was studied to acquire the ideal feeding position of balancing the stable thrust against the efficiency. The effects of multi-DOF motions on electromagnetic characteristics of LSM were analyzed by the proposed model and finite element model. The obtained results indicate that the lateral displacement of multi-DOF motions should be limited to ±28 mm and this model can simulate realistic operating conditions of superconducting LSM. Furthermore, the analytical model reduces the computation time by 96% with high accuracy compared with 3-D finite element model. Finally, experiments were performed to confirm the proposed model with measured magnetic field and forces.