超导-铁磁复合带材力电行为及临界电流的调控机制研究

High-temperature superconducting coated conductors are consisted of superconducting layer and metal substrates, which is signifcant in the application of superconducting electric power devices due to the excellent superconducting properties. With the development of high-temperature superconductors, the mechnical stability and critical current has attracted much attention of researchers. It’s of great significance and scientific value to improve the mechnical stability and critcal current in the applications of superconductors. This proposed project will focus on the following problems: (1) We analyzed the electromechanical behavior of superconducting power transimission cable composed of serveral superconductor/ferromagnet composite tapes. The effects of crack position and distribution on the fracture behavior in a circularly arranged superconducting cable is inverstigated. By changing the distance of adjacent tapes、width and numbers of composite tapes, the mechnical stability of superconducting power transimission cable can be enhanced; (2) We aim to study the developments of vortex structure and critical current with various distributions of antidots and mechanical strain. The superconducting critical current can be modulated and improved by optimizing the size and configuration of antidots. The mechanism of mechanical strain influencing superconduting critical current is given; (3) By establishing the numerical analysis model of critical current of superconductor with magnetic dots, the effects of distribution and magnetization of magnetic dots on the vortex pinning is researched, and the enhancement of critical current with optimal distribution of magnetic dots is achieved.

高温涂层超导体是由超导层和金属基底构成的复合带材，因其优良的超导性能在超导电力设备中具有重要的应用。随着高温超导材料研究的发展，超导体的力学稳定性及其临界性能引起了学者的重视，增强超导体的力学稳定性以及提高临界电流对于超导体的应用具有重要的科学意义。本项目拟展开以下三方面的研究工作：(1)分析由多个超导/铁磁复合带材组成的超导电缆的力电行为，研究裂纹位置和分布对圆周排列结构超导电缆断裂行为的影响，探讨通过改变条带带宽、间距和数量来增强超导电缆力学稳定性；(2)研究孔洞缺陷的分布类型和力学应变对超导涡旋排列结构和临界电流的影响，通过优化孔洞的大小和分布来调控和提高临界电流，揭示力学应变影响超导临界电流的微观机理；(3)建立含磁点超导体临界电流的数值分析模型，研究磁点的分布和磁化强度对涡旋钉扎作用的影响，寻求较优参数的磁点分布来提高超导临界电流。

高温涂层超导体是由超导层和金属基底构成的复合带材，因其优良的超导性能在超导电力设备中具有重要的应用。随着高温超导材料研究的发展，超导体的断裂行为及其临界电磁性能引起了学者的重视，增强超导体的力学稳定性以及优化临界电磁特性对于超导体的应用具有重要的科学意义。本项目取得的研究成果如下：（1）揭示超导复合带的断裂行为随裂纹位置的变化规律。从理论上预测在不同磁化阶段裂纹沿超导厚度方向移动时最可能发生断裂破坏的裂纹位置和磁化强度的大小。（2）揭示不同类型磁通钉扎中心与超导临界性能的影响规律。缺陷过多反而为磁通涡旋运动提供了便利通道，降低钉扎效应并导致临界电流变小。（3）提出调控超导电磁特性的新方法，该方法相比于固定钉扎中心，具有高度可调性。