三根高温超导扭绞方形线的交流损耗实验研究

Experimental study on AC loss of triple-twisted HTS square wires

探究多股高温超导方形线扭绞之后的交流损耗特性,是实现超导缆线结构优化和性能提升的重要研究内容。基于双根扭绞高温超导方形线交流损耗的实验研究,将三根独立的高温超导方形线横向呈“品”字形结构排布,采用电测法,在77 K液氮环境下,对实验样品的交流损耗特性做进一步研究,通过Norris模型对比双根扭绞及未扭绞方形线的实验结果后发现,三根扭绞方形线在扭绞节距减小为75~60 mm的过程中,其交流损耗呈下降趋势且最终达到最小值。说明与实际应用缆线更为接近的三根扭绞方形线实验样品,其交流损耗不被传输电流频率影响的同时,在合理扭绞节距范围内,三根扭绞样品的交流损耗实验值减小更加明显,为高温超导方形线在缆线领域的实际应用提供了充分的理论依据。

It is important to research content to optimize the structure and improve the performance of superconducting cable to explore the AC loss characteristics after twisted multi-strand HTS square wire.Based on the experimental study of the AC loss of the double-twisted high-temperature superconducting square wire,three independent high-temperature superconducting square wire were arranged in a"品"-shaped structure laterally,and the electrical measurement method was adopted,under 77K liquid nitrogen environments,the AC loss characteristics of the experimental samples were further researched.The Norris model was used to compare the experimental results of double-twisted and untwisted square wire.It is found that the triple-twisted square wire exchange in the process of reducing the twist pitch of 75 mm to 60 mm,the AC loss is a descendent and eventually reaches the minimum.The triple-twisted square wire samples are closer to the actual application cable.While the AC loss of the sample is not affected by the frequency of the transmission current,the experimental value of the AC loss of the triple-twisted samples is reduced more obviously within the reasonable twisting pitch range,which can provide a sufficient theoretical basis for the application of high-temperature superconducting square wire in the field of cables.