【作者】 王兴志；

【导师】 王家素；

【作者基本信息】 西南交通大学 ， 电工理论与新技术， 2005， 硕士

【摘要】 高温超导材料的发现激起了物理学界、数学界和工业界的广泛关注,其研究涉及材料的微观结构、半宏观电磁特性和宏观尺度的工程应用等方面。由于高温超导材料可以工作在液氮温区,具有较强的抗磁性和磁通钉扎性,可以构成自稳定的磁悬浮系统,从而大大促进了高温超导磁悬浮系统研究的发展。目前,围绕该高温超导磁悬浮系统的应用主要包括:高温超导磁悬浮轴承、飞轮储能、无源自由振动平台、陀螺仪和磁悬浮列车等。而研究这些系统的核心问题可以归结为高温超导体与永磁体之间的磁相互作用。本文基于永磁导轨与高温超导材料组成的磁悬浮系统分析其磁悬浮刚度特性,目的在于揭露磁刚度的规律,为基于永磁导轨的高温超导磁悬浮应用提供实验数据和理论分析参考。 本文首先通过实验研究的方式系统研究了高温超导磁悬浮系统的磁刚度特性。通过改变相互作用的空间位置、相互作用的时间变量,获得与空间和时间相应的电磁特性参数。受当前实验设备的限制,无法在更大的范围研究准静态条件下的磁刚度特性,所以借助数值分析的方法,通过计算机编制程序模拟相关电磁特性行为。为了兼顾算法的效率和通用性,本文引入矩量法分析局部超导体单元的电磁特性,而全局单元采用有限元法综合处理。考虑到数据的前后处理问题,本文采用面向对象的方式编写相关程序代码,中间调用矩量法求解模块解决算法速度和收敛性问题。由于计算程序采用模块化的设计思路,很容易考虑各种导电媒质方程,如临界态模型、磁通蠕动和磁通流动模型以及Power-law模型等等。最后本文根据编制的程序代码分析了各种参数对磁刚度特性的影响,由于数值分析参数来源于理论计算和实验结果的比对,数值分析的结果具有一定的参考价值。更多还原

【Abstract】 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更多还原