薄带高温超导体的电—磁—热—力多物理场强耦合计算模型及其应用

Superconducting strips, represented by YBCO coated superconductor, owning the merits of high engineering critical current and excellent uniformity of superconducting performance, is the key material for the development of high-temperature superconducting (HTS) electrical engineering technology. Therefore, a numerical model that can simulate the superconducting strips with strongly multiphysics, is indispensable to predication of operation and design optimization of HTS electromagnetic devices. Based on the deep research of high dimensional singularity and nonlinear electromagnetics of HTS strips, the mathematical governing equations will be developed for strongly coupled multiphysics of electromagnetics, thermal and mechanics. After that, a numerical solver and its convergence standard will be proposed and the parallel computing program will be developed. Then, the experiments for validation will be proposed and conducted. This strongly-coupled model is a breakthrough, compared with the present loose-coupled or sub-coupled ones. Finally, based on the strongly-coupled model, we will build the numerical multiphysics model and its fast solving scheme for the large-scale HTS magnet and multiple turns of HTS strips, then we will describe and explain the servicing characteristics of HTS magnet when operating under typical conditions, such as alternating changed magnetic fields and movements. With these works, we will propose viable methods to improve the operational stability and scientific grounds of engineering application for HTS strip magnets.

以钇系涂层带材为主的薄带超导体具有工程临界电流高、性能一致性好等优点，是发展高温超导电工技术的关键材料，建立能准确模拟其多物理场耦合特性的计算模型对理论预测与优化设计高温超导电磁装置十分重要。在研究薄带超导体的尺寸奇异性和电磁非线性特征的基础上，建立能同时描述薄带超导体内部电、磁、温度和应力应变等多物理场强耦合作用的数学控制方程，提出多物理场混合自由度条件下有效的数值求解方法及其稳定收敛判据，建立与之适应的快速并行计算算法，研究等效试验验证方法并实施模型验证，突破目前相关理论模型研究仍处于松（亚）耦合的滞后局面。以超导强磁线圈典型电磁装置为具体应用对象，研究建立大尺寸多匝薄带超导磁体的多物理场强耦合数值计算模型及其快速求解算法，阐明典型工况（如交变磁场、动态运行）下薄带超导磁体的多场耦合服役特性，提出改善薄带超导磁体运行稳定性的方法，为薄带超导磁体的工程应用提供科学判据。

以YBCO涂层超导体为的超导带材，具有工程临界电流高、性能一致性强的优点，是发展高温超导电工技术和装备的关键材料。建立准确模拟超导带材磁体的多物理场特性的计算模型对其应用十分重要。本课题率先开展了超导带材线圈磁体在超导直线电机中的多物理场建模、数值计算和实验研究，首先建立超导带材的基于磁场强度H法的电磁控制方程，为克服超导带材尺寸的强奇异性，建立了均质化模型并验证了该模型的有效性。基于矢量磁位和矢量电位结合的方法建立高温超导磁体的临界电流瞬态计算模型，利用该模型可准确计算超导磁体的临界电流大小。在传统自洽模型中引入均一化方法建立了一种改进的自洽模型，利用该模型可以准确有效地估计超导磁体的临界电流分布，同时可以考虑非均匀外场对超导磁体临界电流的影响。利用温度控制方程，建立了超导线圈磁体的电磁-热多物理场强耦合方程。在上述模型基础上分别计算了跑道型线圈磁体在超导直线电机应用中的电磁、热、力等特性。针对超导带材堆叠磁体在超导磁悬浮和超导飞轮轴承的应用，分别开展了实验和数值研究。上述模型和实验成果为超导带材磁体在超导直线电机、超导磁悬浮等领域的应用提供了重要理论工具和指导。