带有屏蔽层的BSCCO电缆的交流损耗特性研究

摘要

In order to research the AC loss characteristics of a multi-layered conductor and a shield in a high temperature superconductor (HTS) cable,we prepared a five-meter HTS cable sample with 22.9kV/50MVA,and attached voltage-leads to both the conductor and the shield.To investigate the effect of transport period on their AC losses,we also applied current with the same magnitude and opposite direction to the conductor and the shield from a few cycles to several minutes.The tests show that the AC loss measured from the lead attached to the shield (shield-lead) is constant regardless of transport period.But the measured loss from the lead attached to the conductor (conductor-lead) is greatly dependent on transport period.It is why that heat transfer is not easy to the surrounding coolant due to thick insulator around the conductor.As transport period becomes longer and the conductor's temperature rises,thus the AC loss measured from the conductor-lead increases.In addition,the measured loss from the conductor-lead is 1.5 times larger than that from the shield-lead,particularly for the transport period of a few cycles.%为了研究在HTS电缆导体层和屏蔽层的交流损耗,我们准备了5米长22.9KV/50MVA的BSCCO HTS电缆,在导体层和屏蔽层都附上电压引线,并在几毫秒到几分钟内给导体层和屏蔽层通大小相等、方向相反的电流,以测试通电时间对于交流损耗的影响.实验表明,从屏蔽层引线上测出的交流损耗和通电时间无关,但从导体层引线上测量出的损耗值却很大程度依赖于通电时间,这是因为导体层周围很厚的绝缘层导致热传输很难到达周围的冷却剂.当通电周期变长时,导体层的温度升高,通过导体引线测出的交流损耗增加,尤其在通电若干周期后,导体层引线测出的损耗值比在屏蔽层引线测出的损耗值大1.5倍.