共查询到19条相似文献,搜索用时 171 毫秒
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聂新毅王豫王秀芳严仲明廖骁勇 《低温物理学报》2017,(2):32-37
磁耦合谐振式无线电能传输技术可以实现较远距离和较大功率的能量传输.由于它的便利性和安全性,它可以被应用到各种电子产品的无线充电技术中.但由于传输效率和传输距离等问题,它还不能实现商业化.针对这些问题,本文提出用超导中继线圈替换常规中继线圈的方案.超导线圈相对于常规中继线圈可以承载更大的电流密度,有更低的电阻和更高的品质因数(Q),因此它可以减少线圈自身的阻抗损耗,传输更多的能量.本文实验结果表明:在相同条件下超导线圈的品质因数是铜线圈的三倍左右;并证明用超导线圈作为中继线圈的磁耦合谐振式无线能量传输系统可以提高传输效率和增加传输距离. 相似文献
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磁耦合共振式无线电能传输技术因其可以实现中距离和高效率的电能传输而被广泛重视。采用超导线圈代替常规铜线圈的无线输电系统,因临界温度下具有较小的损耗和较高的品质因数,可望大大提高系统的能量传输效率。分别构建了基于高温超导发射线圈的超导无线输电系统和基于铜发射线圈的常规无线输电系统,实验研究了超导线圈和铜线圈无线输电系统的能量传输效率与轴向距离和径向距离之间的关系。仿真和实验结果表明:相同条件下,无线输电系统使用超导发射线圈代替铜发射线圈可以有效提高系统能量传输效率,并改善系统在线圈未对准情况下效率的衰减。 相似文献
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设计了一种高温超导平面式梯度计的探测线圈,利用这种探测线圈与超导量子干涉器件(SQ UID)耦合,可以制成二阶或更高阶的高温超导SQUID平面式磁场梯度计.设计的探测线 圈由两个闭合环路组成,每个闭合环路是由若干个环路通过细小的连接通道连接而成.两个 闭合环路由一条超导窄带分割,将SQUID与这条超导窄带耦合可以测出超导窄带上的电流大 小.通过调整各个环路的形状、面积和位置,可以使超导窄带上的电流与磁场的高阶梯度成 正比,从而测得磁场的高阶梯度. 通过计算,得到了各个环路的面积、电感以及位置的关 系,在理
关键词:
高阶平面式磁场梯度计
高温超导薄膜 相似文献
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Bi2 2 2 3银包套超导带材是研制高温超导磁体和高温超导强电应用的基础。文中就对高温超导磁体最大运行电流有重要影响的 Bi2 2 2 3银包套带材侧向弯曲形变进行了初步探讨 ,就不同的侧向弯曲率对超导带载流能力的影响进行了实验测试 ,并提出了提高 HTS磁体最大运行电流的方法。 相似文献
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Yuan J Rohan ML Shen GX 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,182(2):298-307
The use of Bi-2223 high temperature superconducting (HTS) tape as a material for gradient coils in MRI is evaluated in this paper. Bi-2223 tapes have a very high critical current and a very low power loss. A HTS tape gradient coil is expected to provide much higher gradient strength and generate much lower heating than a copper coil. Measurements of the AC power loss of Bi-2223 tapes at typical operating frequencies for gradient coils are presented. The degradation of the critical current and its effect on the increase of AC power loss is analyzed. Practical technical issues such as resistance, gradient strength and mechanical performance are also discussed. A prototype Bi-2223 HTS tape gradient coil is evaluated to verify the concept. 相似文献
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ITER电流引线高温超导叠制作工艺及性能测试 总被引:2,自引:0,他引:2
ITER高温超导电流引线载流能力最大要达到68 kA,一根电流引线共需要1000多根银金基Bi-2223高温超导带并联.这些高温超导带分成90叠,每叠由12层带组成.银金基Bi-2223带价格是普通银基Bi系带的4~5倍,而目前欧洲超导公司提供的超导叠的报价几乎是其带价格加倍,所以开发超导叠的制作工艺是非常有价值的.本文详细的介绍了超导叠的真空钎焊制作工艺,并进行了77 K下超导带的接头电阻测试和77 K自场下的临界电流测试,以及模拟在实际运行温度65~5 K条件下高温超导叠的载流能力测试和接头电阻的测试.测试结果证明了此工艺的可行性. 相似文献
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J.Y. Li L. Soubeyroux H.L. Zheng C.S. Li Y.F. Lu L. Porcar R. Tournier L. Zhou 《Physica C: Superconductivity and its Applications》2006,450(1-2):56-60
The phase evolution during melting and recrystallization of (Bi,Pb)2Sr2Ca2Cu3O10 ((Bi,Pb)-2223) core in a Ag-sheathed monofilamentary tape has been investigated. The tape was fabricated by PIT process with powders containing nearly pure (Bi,Pb)-2223 phase. Short samples were melted at 805 °C, 808 °C, 812 °C, 816 °C, 831 °C, slowly cooled at 1.5 °C/h under flowing 1.6% O2 balanced with argon and quenched in air at room temperature. X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) were applied for the phase identification. The results show that (Bi,Pb)-2223 core is partially melted into a liquid and alkaline earth cuprates (AECs), mainly 2:1-AEC, at 805 °C, 808 °C, 812 °C, and well reforms directly from the melt during the slow cooling. More (Bi,Pb)-2223 phase is decomposed at temperatures higher than 816 °C, but cannot recrystallize, indicating that a partial melting at some temperatures around a given temperature range is essential to (Bi,Pb)-2223 phase reformation. The melt composition moves from that between “2223” and “2212” stoichiometries towards 2212-like stoichiometry with increasing temperature. This seems to lead to the conclusion that (Bi,Pb)-2223 phase decomposes incongruently into a 2212-like liquid and (Ca,Sr)-cuprates. 2:1-AEC plays the most important role in (Bi,Pb)-2223 melt-recrystallization process. Our results also reveal that plate-like shape (Bi,Pb)-2223 grains can be obtained via melting and recrystallization if the optimum processing conditions are used. 相似文献
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介绍了关于Bi(2223)/Ag带超导电流的特性,包括本征钉扎,Ic与Lorentz力大小的关系,Ic的磁滞。也就是说,Ic的大小不仅与磁场的历史有关,而且与样品在磁场中取向的历史也有关。提出了Ic磁滞的物理解释。评述了Bi(2223)/Ag带中导电的各种模型,包括砖墙模型、铁路道岔模型和自由流通模型。最后指出提高超导电流密度的可能途径。 相似文献
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Hirotaka Ogawa Akinori Kan Makoto Ohsashi 《Physica C: Superconductivity and its Applications》2008,468(6):447-452
The superconductivity of ZnO-doped (Bi, Pb)-2223 thick film on the Ni and NiO substrates, which was prepared by the spray deposition technique with cold forging, was investigated by characterizing the critical current density (Jc), the critical temperature (Tc), the orientation factor (f), and the microstructure of the film. The thickness of the thick film prepared by the spray deposition method was approximately 10 μm. The maximum Jc value of (Bi, Pb)-2223 film on NiO substrate was approximately 2200 A/cm2 (Ic = 110 mA) when the film was sintered at 865 °C for 1 h with a cooling rate of 0.5 °C/min from 865 °C to 650 °C; in the case of Ni substrate, a maximum Jc value of approximately 2000 A/cm2 (Ic = 100 mA) was obtained for the (Bi, Pb)-2223 thick film when a cooling rate was 3 °C/min. Such a difference in the Jc values of (Bi, Pb)-2223 thick film on Ni and NiO substrates is attributed to the presence of reaction layer at the (Bi, Pb)-2223 and substrate interface. In addition, the variations in the orientation factor of (Bi, Pb)-2223 thick film on NiO substrate related to those of Jc values. The Jc values of (Bi, Pb)-2223 film on NiO substrate with ZnO doping extremely depended on the amount of ZnO doping and the 0.5 wt% ZnO-doped (Bi, Pb)-2223 thick film deposited on NiO substrate, which was sintered at 835 °C for 1 h in air with a cooling rate of 1 °C/min, showed a Jc value of approximately 1200 A/cm2 (Ic = 60 mA). Thus, it is considered that a small amount of ZnO doping was effective in lowering the sintering temperature of (Bi, Pb)-2223 thick film, resulting the improvement in the intragranular weak bonding or Josephson junction. 相似文献
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低温/高温复合超导体的热稳定性的数值模拟研究 总被引:2,自引:0,他引:2
本文提出了一种高温超导体与低温超导体直接复合成混杂结构的复合超导体的导体模型.针对NbTi/Bi2223复合超导体的热稳定性进行了初步的理论模拟研究,结果表明低温/高温复合超导体的最小失超能远大于低温超导体,失超传播速度介于纯低温超导体和高温超导体之间,对于超导磁体的热稳定和保护具有重要参考价值. 相似文献
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对具有不同临界电流的Bi2223/Ag多芯超导材的交流电流电压特性进行了测量和评价,当传输电流的有效值Inns小于临界电流Ic时,交流电压的大小与传输电流的频率成正比;但Inns接近临界电流时,不同频率所对应的交流电压的大小之间的差别减小了,所有的曲线都汇聚成一条曲线,传输电流的频率分别为40Hz,60Hz,80Hz,200Hz及300Hz时,我们测量了交变传输电流在Bi2223/Ag带材中产生的自场损耗。结果表明当传输电流的频率较低时,实验结果与基于Bean模型的Norris方程预期的结果一致;另外,实验结果表明存在一个电流I′,它的值小于任何一个样品的临界电流,本实验中I′的值是10安培,在传输相同大小的电流Inn且Inns〈I′时,Boi2223/Ag带材的交流损耗与它的临界电流成正比;但当Inns〉I′ 相似文献