An Analytical-Experiment Coupling Method to Characterize the Electrodynamic Suspension System at Various Speeds

In this article, we propose a novel analytical-experiment coupling method to characterize the electromagnetic forces of superconducting electrodynamic suspension system. The basic idea of this method is that, the induced currents of the ground null-flux coils (NFCs) are predicted by analytical calculation, but the electromagnetic forces on the onboard superconducting magnets are directly measured. To ensure the calculation accuracy of induced current, a Neumann's formula-based analytical model was derived and its accuracy was confirmed by comparing with the finite-element model and the existing analytical model, which is based on the harmonic approximation. The prominent merit of this method is that it is free of high speed rotating motion and thus, has no limitations of testing speed. We further made a proof-of-principle experimental setup, which consists of a coated-superconductor magnet and a few NFCs, to check the effectiveness of the proposed method. By this setup, the dependence of electromagnetic forces, i.e., levitation force, guidance force, and drag force, were measured as a function of displacement and speed. It was found that, results obtained by the proposed method are in agreement with 3-D finite-element simulation, which to some extent validatesthe proposed method.