Measurement and Numerical Calculation of AC Losses in Second-Generation High Temperature Superconductor Current Leads

摘要:

为了研究高温超导电流引线结构对交流损耗的影响，制作了2种不同结构的高温超导电流引线。基于Clem模型，把外部磁场对交流损耗的影响加以考虑。在电流引线截面上建立了坐标系统，通过采取坐标平移和坐标旋转，可以得到高温超导电流引线内部磁场分布。 在以上基础上，建立矩形骨架 (RSCL) 和十二边形骨架 (DSCL) 两种不同结构的高温超导电流引线的交流损耗计算模型。运用MATLAB编写计算模型，计算两种不同结构的高温超导电流引线的交流损耗。最后，在液氮环境中采用电气方法进行两种不同结构电流引线交流损耗的实验测量。在不同的电流和不同频率下测量两种不同结构的电流引线的交流损耗，将理论结果和测量数据进行比较，并就结构对交流损耗的影响进行了分析。交流损耗计算结果表明，坐标转换模型比Norris模型更准确，十二边形骨架（DSCL）的交流损耗比矩形骨架（RSCL）小。

Abstract:

In order to study the effects of the structures of HTS current leads on AC losses, two different structure HTS current leads were fabricated. Based on the Clem model, the effects of external magnetic field on AC losses were taken into account. The coordinate system on the cross section of the current leads was established. By taking the advantage of coordinate translation and coordinate rotation, the distributions of the magnetic field in HTS current leads were obtained. On the basis, AC loss calculation models for the two different structure HTS current leads, rectangular skeleton current lead (RSCL) and dodecagon skeleton current lead (DSCL) were built. Then, calculation programs were compiled using MATLAB and AC losses of the two different structure HTS current leads were calculated. Finally, the experiments of AC losses of HTS current leads were carried out by an electrical method in liquid nitrogen environment. AC losses of the two different structure current leads were measured at different currents and different frequencies. The theoretical results and measured data were compared and the effects of the structures of HTS current leads on AC losses were analyzed. The calculation results of AC losses show the coordinate transformation model is more accurate than the Norris model. The results also show AC loss of DSCL is smaller than that of RSCL.