50 kA超导变压器杜瓦及高温超导电流引线的设计与优化

CICC超导导体性能测试用50 kA超导变压器由初级线圈和次级线圈组成,初级线圈浸泡在4.2 K液氦低温杜瓦中,次级线圈为CICC导体采用4.2 K/354 637 Pa超临界氦迫流冷却,液氦和超临界氦均由500 W/4.5 K制冷机提供,变压器低温杜瓦的理论液氦蒸发率为1.52 L/h。为减少电流引线漏热,超导变压器采用B i-2223/AgAu高温超导(HTS)二元电流引线,并且在颈管中部设计了一个新型的直接用液氮冷却的热截流装置来截断电流引线高温端的热流;最后对铜电流引线部分进行了尺寸优化计算,得到最佳截面积和直径分别为28 mm2和6 mm。     

50 kA超导变压器的设计及研制

针对管内铠甲超导导体测试装置的需要,设计并研制了50 kA超导变压器,详细介绍了超导变压器的主要设计参数和主要部件的研制加工.变压器初级线圈及次级线圈均采用NbTi超导股线.初级线圈由单根NbTi股线绕制而成,次级线圈由441根NbTi股线经过多级绞缆而成.为了便于安装和拆卸,接头采用单室低电阻接头方式;为了有效减小接头电阻,采用预压灌锡的方法来制备接头.变压器初级线圈采用LHe浸泡冷却方式,次级线圈及接头采用超临界He迫流冷却方式.整个低温环境由500 W@4.5 K制冷机提供.     

传导冷却50kA CICC导体接头设计

针对管内电缆导体(CICC)导体的测试装置,对其超导导体接头的设计进行了详细的讨论.超导接头拟采用单室接头结构,采用超临界He迫流冷却接头盒导电铜基板,通过传导冷却方式冷却导体电缆.对接头稳定性以及传热进行了分析.     

ITER 10kA高温超导电流引线测试装置低温系统的研究

为ITER CC 10 kA高温超导电流引线服务的低温性能测试装置已研制完成,并成功运行。其低温系统主要由500W/4.5 K氦制冷机,真空杜瓦,低温组件(低温阀门,过冷槽,管道加热器,热防护层),汽化器及低温传输管线等部分组成。本文对真空杜瓦和过冷槽进行设计,并讨论该低温系统的冷却流程方案,最后通过电流引线10 kA稳态实验结果对低温系统的运行效果进行分析,结果表明该低温系统运行稳定,能满足ITER CC电流引线的测试需要。     

1.8K常压超流氦低温系统的设计与分析

中国科学院等离子体物理研究所ITER CC导体测试装置背景超导磁体,由4.2 K液氦浸泡冷却,能够提供7 T背景场,为了满足超导导体测试需要更大背景场(10 T)的要求,将采用1.8 K超流氦浸泡冷却。针对该测试装置的低温系统设计了一种1.8 K常压超流氦低温系统,给出了该系统的关键组成部分并对获取1.8 K常压超流氦的流程进行了分析。针对预冷与节流相结合获取1.75 K超流氦方案进行了分析和计算,同时针对此方案给出了其物理过程的T-s图,计算了1.75 K超流氦液体得率。     

ITER 68kA高温超导特大电流引线的冷端漏热

ITER高温超导电流引线载流能力最大要达到68 kA,其试验件于2008年底加工完成并进行了低温试验,在载流能力、接头电阻、漏热和安全性等关键参数上取得了重要进展.讨论了ITER高温超导电流引线超导段冷端(5 K)漏热的理论值计算,并用热导率积分法进行了低温漏热测试,结果表明理论值与试验值基本吻合,试验件冷端漏热满足ITER国际组要求.     

合肥光源超导波荡器用二元电流引线的设计研究

电流引线作为连接室温电源与低温超导磁体的部件,温度跨越范围大,是低温恒温器的最主要热负荷之一。超导波荡器(SCU)用高温超导电流引线主要采取小型制冷机直接传导冷却的形式,通过对合肥光源超导波荡器(HLS-2 SCU)用400 A高温超导二元电流引线铜段的长度、截面等几何参数进行理论优化,以减小小型低温制冷机的热负荷。考虑室温端热阻以及铜段低温端的温度对最小漏热的影响,得出铜段最佳值参数。通过有限元仿真计算结果进行验证,得出的结果吻合的较好。最终确定了400 A高温超导电流引线的设计参数。     

液氮传导冷却型高温超导电流引线研制

80 A和200 A液氮传导冷却型高温超导(HTS)电流引线由铜引线段、中间过渡段和高温超导段组成,HTS热端采用液氮传导冷却,HTS冷端采用液氦传导冷却。铜引线段工作在室温到中间温度(~80 K),高温超导段工作温区6—80 K。介绍该传导冷却型电流引线的结构设计和低温性能测试。实验结果表明,中间过渡段温度~78 K,高温超导热端温度77 K;80 A、200 A电流引线液氦下稳态测试电流分别为100 A和250 A。     

高温超导变压器技术概述及发展现状

<正>由于超导变压器绕组采用电阻为0、且电流密度高于常规导体的超导材料以及液氦或液氮低温介质冷却和绝缘,所以与常规变压器相比,超导变压器具有损耗小、质量轻、绕组体积小、环境友好和无火灾危险等优点,引起国际上工业界的广泛兴趣。早在20世纪80年代,美国首次提出了基于低温超导体N b T i的1 000M V A以液氦为低温介质的低温超导变压器[1],并相继成功开发了各种形式的低温超导变压器试验样机[2-5]。然而,由于低温超导变压器     

管内电缆导体稳定性研究方法新探

管内电缆导体（ＣＩＣＣ）,是目前大型低温超导磁体的首选导体。随着超导技术的发展,ＣＩＣＣ在大型超导核聚变实验装置及超导储能磁体中的应用具有不可比拟的优越性。为降低导体成本而提出了在ＣＩＣＣ中采用的超导股线配以纯铜股线的设计方案,开展含纯铜股线ＣＩＣＣ稳定性机理及实验的研究,并开发ＣＩＣＣ优化设计软件,对ＣＩＣＣ在高科技术中的应用意义重大。     

The cryogenic system for ITER CC superconducting conductor test facility

This paper describes the cryogenic system of the International Thermonuclear Experimental Reactor (ITER) Correction Coils (CC) test facility, which consists of a 500 W/4.5 K helium refrigerator, a 50 kA superconducting transformer cryostat (STC) and a background field magnet cryostat (BFMC). The 500 W/4.5 K helium refrigerator synchronously produces both the liquid helium (LHe) and supercritical helium (SHe). The background field magnet and the primary coil of the superconducting transformer (PCST) are cooled down by immersing into 4.2 K LHe. The secondary Cable-In-Conduit Conductor (CICC) coil of the superconducting transformer (SCST), superconducting joints and the testing sample of ITER CC are cooled down by forced-flow supercritical helium. During the commissioning experiment, all the superconducting coils were successfully translated into superconducting state. The background field magnet was fully cooled by immersing it into 4.2 K LHe and generated a maximal background magnetic field of 6.96 T; the temperature of transformer coils and current leads was reduced to 4.3 K; the inlet temperature of SHe loop was 5.6 K, which can meet the cooling requirements of CIC-Conductor and joint boxes. It is noted that a novel heat cut-off device for High Temperature Superconducting (HTS) binary current leads was introduced to reduce the heat losses of transformer cryostat.     

Electromagnetic analysis of a superconducting transformer for high current characterization of cable in conduit conductors in background magnetic field

A large cable-in-conduit-conductor (CICC) test facility has been designed and fabricated at the High Magnetic Field Laboratory of the Chinese Academy of Sciences (CHMFL) in order to meet the test requirement of the conductors which are applied to the future fusion reactor. The critical component of the test facility is an 80 kA superconducting transformer which consists of a multi-turn primary coil and a minor-turn secondary coil. As the current source of the conductor samples, the electromagnetic performance of the superconducting transformer determines the stability and safety of the test facility. In this paper, the key factors and parameters, which have much impact on the performance of the transformer, are analyzed in detail. The conceptual design and optimizing principles of the transformer are discussed. An Electromagnetic-Circuit coupled model built in ANSYS Multiphysics is successfully used to investigate the electromagnetic characterization of the transformer under the dynamic operation condition.     

Recovery estimation for over-current test of non-inductive fault current limiters using numerical analysis

When an HTS coated conductor (CC) is used as a conductor of a superconducting fault current limiter (SFCL), the CC is expected to be exposed to the over-current and temperature of the CC is expected to be increased rapidly by electrical joule heating. Because the CC is a composite tape, thermal and electrical properties of composite materials could affects over-current limiting capacity and recovery time of SFCL. This paper presents experimental and numerical results of over-current test and recovery time measurement test on four bifilar wound SFCL modules. The temperature transitions of the samples were estimated from total electrical resistance of the coils. We fabricated one bifilar solenoid coil and three bifilar pancake coils whose cryogenic conditions were different from the other coils. An numerical model was also fabricated to simulate the temperature transition and the numerical results were compared with experimental results.     

Conductor and joint test results of JT-60SA CS and EF coils using the NIFS test facility

In 2007, JAEA and NIFS launched the test project to evaluate the performance of cable-in-conduit (CIC) conductors and conductor joints for the JT-60SA CS and EF coils. In this project, conductor tests for four types of coil conductor and joint tests for seven types of conductor joint have been conducted for the past eight years using the NIFS test facility. As a result, the test project indicated that the CIC conductors and conductor joints fulfill the design requirement for the CS and EF coils. In addition, the NIFS test facility is expected to be utilized as the test facility for the development of a conductor and conductor joint for the purpose of the DEMO nuclear fusion power plant, provided that the required magnetic field strength is within 9 T.     

VXI总线的蠕变测试系统

介绍了具有先进ＶＸＩ仪器总线的材料蠕变测试系统。由于设计了为测位移差动变压器初级线圈提供幅度高度稳定的方波信号的方波发生电路以及采用了场效应管从测位移差动变压器输出的方波信号中解调出与位移相应的直流电平，提高了位移测量精度；由于设计了“电位移动”电路，把现场热电偶的电势无损耗地移至测量主机内，保证了温度测量的可靠性，虚拟ＰＩＤ调节器软件使温控设备大大简化。     

Comparison of the quantized Hall resistance and ohm NRC

A report is given of the progress towards the establishment of a quantized Hall resistance (QHR) measurement system suitable for maintaining the NRC (National Research Center of Canada) representation of the ohm. A system using a cryogenic current comparator bridge is described and compared to the previously reported 15 T, 20-mK potentiometric system. General problems concerning the use of the quantized Hall resistance to realize a representation of the ohm are discussed     

宽带脉冲大电流测量及大数据分析技术

多磁路调压变压器的脉冲电流具有频带宽、幅度大的特点,其测量与大数据分析易受到噪声等影响。本文研究了多磁路调压变压器宽带脉冲大电流测量与大数据分析技术,设计了基于法拉第磁光效应和光纤电流传感器的宽带脉冲大电流测量系统方案,采用卷积神经网络对测量得到的海量数据进行处理,消除测量过程中干扰对测量结果的影响。通过与罗氏线圈的测量结果比对,本文研究的方法测量结果的脉冲波形一致性好、脉冲峰值检测准确度较高,脉冲幅值误差符合测试要求。     

Modelization of the thermal coupling between the ITER TF coil conductor and the structure cooling circuit

The ITER Toroidal Field (TF) coils are required not to quench during the most demanding event: a plasma disruption followed by a fast discharge of the Central Solenoid (CS), the Poloidal Field (PF) coils and the Correction Coils (CC). This event creates large heat deposition in the ITER magnet stainless steel structures in addition to the conductor AC losses. In order to prevent quench occurring in the TF conductor, cooling channels, implemented in the TF coil structure (TFCS), have to remove a large fraction of the heat deposited. The first integrated TF and structure mock-up has been manufactured and then tested in the HELIOS cryogenic test facility (CEA Grenoble) to determine the thermal coupling between the TFCS and the TF conductor, both actively cooled by supercritical helium at 4.4 K and 5 bar. It consists in a stainless steel casing, a cooling pipe glued with resin in the casing groove, winding pack (WP) ground insulation, a radial plate and a copper dummy cable-in-conduit-conductor (CICC). Steady state as well as transient thermal characterizations have been completed in May 2015. Simulation results by thermal hydraulic codes (VENECIA/SuperMagnet) and some of the experimental data are presented and discussed. The thermal coupling between the helium in the cooling tube and the TF coil structure is then modelled as an equivalent heat transfer coefficient in order to simplify the thermal hydraulic (TH) models. Comparison between simplified coupling and detailed coupling is presented.     

电子式电流互感器校验方法研究

提出一种校验电子式电流互感器模拟量输出和数字量输出的方法,该方法基于采样测量技术,测量标准电流互感器和被校电子式电流互感器的二次输出,比较二者的差异得到被校电子式电流互感器的比值误差和相位误差。详细分析了电子式电流互感器模拟量输出及数字量输出校验方法的测量误差,论证了该方法的合理性和可行性。根据该方法研制的校验装置样机在国家高电压计量站进行了校准测试,测试结果表明,所研制的校验装置满足校验0.2及以下等级计量用电子式电流互感器的准确度要求。