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以YBa_(2)Cu_(3)O_(7)(YBCO)带材为代表的二代高温超导带材被广泛应用于各类超导装备中,由于YBCO超导带材生产长度的限制,其接头技术将在带材的实用化发展中起到至关重要的作用,其中低熔点焊料焊接接头技术由于其工艺简单且能够满足目前二代高温超导材料的应用需求,成为现阶段接头制备的主流技术.本文基于YBCO基本属性,结合目前国内外的YBCO带材生产现状,系统全面地调研了低熔点焊料焊接接头技术的制作工艺及其性能的影响因素,明确了低熔点焊料焊接接头的关键影响因素,梳理了二代高温超导带材接头的焊接工艺流程,为二代高温超导带材接头的制备提供参考。 相似文献
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焊接技术是高温超导带材实际应用中的关键技术,焊接温度、焊料、搭接长度等工艺环节对带材接头性能都有一定的影响.本文针对高温超导一代Bi2223/Ag带材和二代YBCO带材的接头焊接工艺进行了系统的实验研究,包括焊接温度对带材性能的影响、不同焊料及搭接长度对接头性能的影响等.实验结果表明:一代Bi2223/Ag高温超导带材在400℃焊接温度以内载流能力不会发生明显退化,而二代YBCO带材对温度较敏感,在200℃以上带材性能会出现明显退化;在Bi2223/Ag及YBCO带材各自的焊接温区内,不同焊料对带材接头性能有一定的影响,但液氮温度下接头电阻均能达到10-8Ω量级,其临界电流与带材短样相比无太大变化;两种超导带材的接头电阻均与焊接搭接长度成反比,适当增加焊接搭接长度可以减小接头电阻,提高带材接头性能. 相似文献
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本文对高温超导双饼线圈的绕制、测试和结果进行了讨论和分析,在此基础之上对传导冷却高温超导磁体进行了电磁分析,通过对6到21个双饼线圈组成的磁体的各种参数进行计算,得到了一系列变化曲线,从中可以看到各个参数的变化趋势,以便有效设计高温超导磁体。 相似文献
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It is necessary to develop HTS conductors with a large current capacity and low AC loss characteristics for practical use of HTS power devices. For large capacity power applications, HTS tapes such as Bi-2223 tapes and YBCO coated conductors are assembled. So, it is important to evaluate the characteristics of current distributions in such assembled HTS tapes. However, an adequate measurement method has not been established. In this study, we have tried the development of an indirect measurement method to evaluate the current distributions in stacked HTS tapes. In this method, the current distributions are indirectly found from the results of the field distributions measured by a pickup coil located around the surface of the sample tapes. To confirm the accuracy and the sensitivity of this method, current distributions in a test conductor made of copper tapes are measured. Numerical and measured current distributions are compared. Using this method, the current distributions in stacked Bi-2223 tapes are measured at room temperature and 77 K. On the basis of the obtained results, the characteristics of the AC current distributions in the HTS tapes are discussed. 相似文献
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根据ITER电流引线的要求,设计和试验了分别由全铍铜(Be2%Cu)、全不锈钢(SS)和二元金属(BeCu/SS)三种不同类型分流器制作的68kA电流引线的1/90试件。研究了超导段各组件的性能,详细讨论了失冷故障实验结果。结果表明,对比全铍铜和全不锈钢分流器,二元分流器制作的超导模件更能够提高安全性以及减小冷端漏热,满足ITER高安全性和低热负荷的要求。 相似文献
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I. A. Al-Omari N. Shaked A. Friedman Y. Wolfus A. Shaulov M. Sinvani Y. Yeshurun 《Physica C: Superconductivity and its Applications》1998,310(1-4):111-115
The interplay between AC and DC currents in a High-Tc Superconducting (HTS) coil, made of multifilamentary silver-sheathed Bi-2223 tape, was investigated. We observed that the application of a small sinusoidal current in the frequency range of 50–500 Hz into the coil, while it is already carrying a DC current in the range of 16–22.5 A, caused an increase in the coil DC voltage. The DC voltage increment due to the AC signal is found to increase linearly with frequency and quadratically with amplitude. The DC voltage increment increases as the coil current grows towards its critical value of 22.2 A. This result may be important in some power applications such as fault current limiters (FCL) and superconducting magnet energy storage (SMES) based on HTS coils. 相似文献
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本文阐述了用于高温超导磁体电磁结构优化设计的一种新方法,与一般优化方法不同之处在于其不用定义磁体的初始结构形状,采用该方法可以得到满足规格和性能要求的较佳磁体结构.通过此方法优化设计了一个中心磁场为3T的Bi系高温超导磁体,其设计结果与满足同样要求且经过优化的单螺管高温超导磁体的设计结果作了对比,由结果表明该方法具有很好的优化效果. 相似文献