Design and Experiment of a New Maglev Design Using Zero-Field-Cooled YBCO Superconductors

The existing high-temperature superconducting magnetic levitation (Maglev) vehicles are based on field-cooled (FC) superconductors mainly to guarantee vehicle lateral stability. Usually, this solution presents two drawbacks: levitation and guidance forces depend on how the FC process has been featured, and flux-flow phenomenon, which induces significant power losses in superconductors during the vehicle´s displacement, can put them out of superconductivity state. To minimize these problems, a zero-field-cooled (ZFC) Maglev vehicle was designed and successfully developed in our laboratory. Measurements of its levitation and guidance forces and also its vertical and damping properties were carried out. These results, when compared with those ones from an FC vehicle, show that the ZFC vehicle has higher levitation forces and similar guidance force values. However, guidance forces do not depend on cooling height value as what happens in an FC vehicle, despite that the ZFC vehicle also presents some power losses. The experimental results indicated that power losses from vertical and lateral vehicle oscillations are lower in a ZFC one. However, this effect will have to be compensated by using some technique to reduce ZFC vehicle oscillations in the future.