Dynamic force properties of a high temperature superconducting maglev test vehicle

In order to investigate the feasible application of a high-T_c superconducting (HTS) levitation system to a maglev train or a space vehicle launcher, we construct a demonstration maglev test vehicle consisting of two linear permanent magnets (PM) guideways and a test levitator with multi-block melt-processed YBaCuO superconductors. By using a vibration testing technique, we measure the dynamic force properties of the test vehicle in different field cooling (FC) and loading conditions. In both vertical and lateral vibration directions, resonance frequencies and related magnetic stiffness show large dependence on the FC height (FCH) and the load weight. The resonance frequencies increase as the FCH decreases or the load weight is reduced. The magnetic stiffness is also increased by using the low FCH or adding the load weight. It is shown that the dynamic properties of the HTS levitation system are closely related to the flux history in superconductors and the motion process of the system. Finally a low FC scheme and a preloading method are proposed to improve the stability of the HTS maglev vehicle.