Effect of Eddy-Current Damper on the Dynamic Levitation Force in High-Temperature Superconducting Maglev System
The research on dynamic characteristics of a high-temperature superconducting (HTS) maglev system reveals that the system is a low-damping dynamic system and an eddy-current damper is able to improve the systemic damping. The influence of the eddy-current damper on the dynamic levitation force of the HTS maglev system was studied in the paper. Several different thicknesses of copper plates were respectively set at the bottom of the superconductors to work as the eddy-current damper. Dynamic levitation forces were measured above a rotating permanent magnet guideway (PMG) under a velocity range from 15 to 120 km/h. For the sake of estimating the effect of the copper damper on the dynamic levitation force, the peak values, steady values, and attenuation ratios of dynamic levitation forces are comparatively analyzed in two conditions of no copper damper and having copper damper. We also perform the magnetic field measurement experiment in the top and bottom surface s of 0. 1 -mm- thick copper damper by two Hall sensors, the results of which indicate that the electromagnetic shielding effect of the copper plate becomes more obvious with the increase of the rotational velocity of PMG. We conclude that inserting the eddy-current damper at the bottom of the superconductors has a weakly positive effect on the promotion of dynamic levitation force. So, the eddy-current damper can be applied to the HTS maglev system to enhance systemic damping without substantially affecting the systemic dynamic levitation force under a designated running velocity.