论文部分内容阅读
高温超导YBCO带材严重的各向异性,使得YBCO磁体的交流损耗特性比BSCCO磁体更加复杂。利用有限元方法研究了匝数多达1000匝的YBCO磁体的交流损耗特性。该方法基于H方程,考虑了YBCO带材与磁场强度和方向相关的临界电流密度以及高温超导体高度非线性的E-J关系。由于磁体匝数众多,采用均质化bulk近似方法简化了磁体建模,加快了计算速度,并以200匝带材组成的双饼为例,对比均质化Bulk模型和考虑超导层实际尺寸的参考模型,验证了该方法的可靠性。此外,还详细分析了不同传输电流上升率、幅值以及带材的n值和临界电流等参数对YBCO磁体交流损耗的影响。
The severe anisotropy of HTS YBCO tapes makes the AC loss characteristics of YBCO magnets more complex than that of BSCCO magnets. The AC loss characteristics of YBCO magnets with up to 1000 turns are studied by finite element method. Based on the H-equation, this method considers the critical current density of the YBCO strip in relation to the strength and direction of the magnetic field and the highly nonlinear E-J relationship of the high temperature superconductor. Due to the large number of magnets, the homogenization bulk approximation method is used to simplify the magnet modeling and speed up the calculation. Taking the double cake with 200 turns of strip as an example, the homogeneous bulk model is compared with the actual size of the superconducting layer The reference model verifies the reliability of this method. In addition, the influence of different transmission current rising rate, amplitude, n value of the strip and critical current on the AC loss of YBCO magnet was also analyzed in detail.