Magnetic Shielding Design of Onboard Superconducting Magnet for Electrodynamic Suspension Train

The superconducting electrodynamic suspension (EDS) train has been expected to be a promising candidate for the future ultrahigh-speed transportation due to its excellent levitation and guidance stabilities, high lift-to-drag ratio, and being free of active control. As a core component of the EDS train, the onboard superconducting magnet (SCM) is usually required to generate a strong magnetic field, however, which may threaten the safety of passengers. Therefore, it is indispensable to design a magnetic shielding for onboard SCM, aiming at minimizing the magnetic field in the coach of the vehicle. In this article, a three-dimensional finite-element method model for solving the electromagnetic problems of the magnetic shielding system is established and validated by experimental results. Prior to global optimization, the effects of the thickness, multilayer structure, and partition of the shielding plate on the magnetic shielding are discussed primarily. It was found that the thickness has a great impact on the shielding effect, whereas the influence of the multilayer structure is weak. Moreover, the weight of the magnetic shielding plate can be effectively reduced by partitioning it into several blocks with different thicknesses. Based on the above-mentioned studies, the magnetic shielding plate is finally optimized in consideration of the thickness, multilayer structure, and partition. Consequently, the weight of the magnetic shielding plate can be reduced by 20% compared with the original one.