Fundamental Studies on Characteristic Evaluation and Application of Bulk Superconductor

1.利用YBCO块体和多个电磁铁，设计并建造了一种新型有源磁悬浮系统。利用三个和五个电磁铁系统控制悬浮高度实现了连续悬浮，并利用有限元计算程序研究了块体内部的电磁行为。2.提出了一种二维运动的磁悬浮装置，即悬浮X-Y传送器。针对实际设计的X-Y悬浮式输送机，对其升力和恢复力进行了实验研究，并开发了基于三维混合有限元-边界元方法的高温超导块体动态电磁行为仿真程序。通过实验和数值模拟，阐明了各种作用力与超导电流和磁场分布之间的关系。3.制作并测试了一种基于…的直线同步执行器更多的是双面初级和场冷却的YBCO块状次级。从同步力矩、启动推力和吸合特性三个方面对其静态特性进行了实验研究。并编制了基于有限元的仿真程序，研究了一次绕组产生的磁场作用下块体内部的电磁行为。4.实验研究了不同幅值和频率的外加交流磁场作用于圆盘状YBCO块材时势垒场的转变。并利用新开发的基于有限元的计算机程序进行了数值模拟。在频率为50赫兹的长期施加场中进行了俘获场衰减实验。衰减突然变大，最后囚禁场消失。这意味着屏蔽电流在块体内的分布会受到时变磁场的影响，而瞬变磁通的运动会导致温度升高，最终导致势垒场的降低。较少

1.A new type of active-maglev system is designed and constructed using YBCO bulk and multiple electromagnets. And the continuous levitation was demonstrated with controlling the levitation height using three and five electromagnets systems and electromagnetic behavior within the bulk was investigated using a FEM computer program.2.A magnetic levitating device was proposed with two-dimensional movement, namely a 'levitating X-Y transporter'. For a real design of levitating X-Y transporter, the lift and the restoring force were examined experimentally and a simulation program was newly developed based on the three-dimensional hybrid FE-BE method to analyze the dynamic electromagnetic behaviors of the HTS bulk. Then the relationship between the various forces and distributions of supercurrent and magnetic field was clarified through experiments and numerical simulation. And the design of a levitating transporter was also performed.3.We fabricated and tested a linear synchronous actuator w … More ith double-sided primary and field-cooled YBCO bulk secondary. We experimentally investigated the static characteristic in points of synchronous torque, the starting thrust and the pull-in characteristics. And we developed a simulation program based on FEM to investigate electromagnetic behavior within the bulk exposed to the magnetic field generated by the primary winding.4.The transition of trapped field was experimentally investigated while applying external AC magnetic field with various amplitude and frequency to a disk-shaped YBCO bulk. And the numerical simulation was also performed using a newly developed computer program based on the FEM. The experiment of trapped field attenuation was carried out in long term applying field with a frequency of 50 Hz. The attenuation is abruptly large and finally the trapped field is disappeared. This means that shielding current distribution within the bulk is changed by the time-varying magnetic field and the transient magnetic flux movement results in temperature rise and finally the reduction of the trapped field. Less