Stiffness In High Temperature Superconducting Maglev System

Since the discovery of high-temperature superconductors in 1986 there has been a huge resurgence in interest in superconductivity in both the engineering and physics communities, not only at microscopic level, but also at the meso- and macroscopic levels. The explosion of work in the engineering community is largely a result of the fact that because high-temperature superconductors can operate at liquid nitrogen temperatures, and it is becoming economically feasible to build more and more devices out of superconducting materials. With the advent of high-temperature materials engineerings are examining the possibility of using superconductors in more and more applications such as noncontact bearings, flywheels, momentum wheels, passive vibration free platforms and Maglev vehicles. For the further study on these superconductor and magnet levitation devices, it is important to understand the interaction between a high-temperature superconductor and permanent magnet. In this article, characteristics of both vertical and lateral stiffnesses in different cooling conditions were investigated by both the experimental and the numerical methods.As a detailed approach to the studies on stiffness measurements, I report the results of stiffness experiments that include stiffness matrix as a function of the displacement, the comparison of the behavior of the stiffness matrix in zero field cooling and field cooling, and dependence of the stiffness matrix on path history. Use in applications should be accompanied by theoretical estimations, together with experimental measurements of stiffnesses on the Maglev systems. From the theortical point of view, the study of stiffness on the Maglev system is a complicated task, mainly due to the problem of finding the current penetration inside the superconductors when the applied field is not homogeneous. Several models have been presented. In this article, a numerical method for solving for the current and field distributions inside devices containing type-II superconductors is described. The two-dimensional solution technique accommodates the effects of surrounding media including iron and it can handle systems with an arbitrary number of type-II superconductors and conventional materials. The technique is based on the finite element method, the method of moments and the non-linear voltage-current...