共查询到19条相似文献,搜索用时 562 毫秒
1.
2.
3.
多端柔性直流电网技术的发展面临快速限制短路电流的巨大挑战。超导直流限流器被认为是故障限流的最有效解决方案之一。提出了一种基于分裂电抗器的开关转换型超导直流限流器,该限流器通过限流单元(分裂电抗器的绕组由YBCO带材绕制)与固态开关相配合,稳态时,限流器呈并联结构,等效电感小,运行损耗低;故障发生后,限流器转换为串联结构,并受大电流冲击而失超,产生较大的限流电阻,能够有效限制短路电流。基于MATLAB/Simulink建立了超导限流器模型,仿真分析了限流过程中的电流变化情况,对比分析了开关动作前后的限流情况,验证了该限流器的可行性。 相似文献
4.
5.
6.
《低温与超导》2021,49(5):1-8,13
超导限流器被认为是理想的电力系统短路电流限制手段。主要针对磁屏蔽型超导限流器的电气特性进行系统性的建模研究。首先,基于限流器工作原理和超导材料的特殊电测特性,在PSCAD/EMTDC仿真平台中对磁屏蔽型超导限流器进行了数值模型和电路模型的搭建。随后通过实验室级限流器样机短路实验对仿真模型的可靠性进行了验证,并基于模型完成过流失超机理分析。最后,完成含限流器的上海某10 kV配电网实际系统模型搭建,综合分析磁屏蔽型超导限流器对电网运行状态的影响并探索其限流特性。该文的结论有效证明了磁屏蔽型超导限流器的限流能力,稳定故障电压的能力以及快速的失超自恢复性能。 相似文献
7.
8.
9.
运用超导电力技术研发的超导限流器与电力系统传统的限流装置相比,具有显著的优势,其中饱和铁芯型超导限流器SCFCL(saturated core superconducting fault current limiter)结构简单且具有良好的短路电流限制作用,在其保障电网中电气设备安全运行的同时对系统的暂态稳定性产生了相应影响.通过分析饱和铁芯型超导限流器工作原理在PSCAD/EMTDC中建立其电磁暂态模型,接入到IEEE 3机9节点典型网络中进行时域仿真,观察不同类型故障情况下的功角摆动曲线,分析饱和铁芯型超导限流器的投入对电力系统暂态稳定的有利和不利影响,为饱和铁芯型超导限流器在电网里的应用提供理论参考. 相似文献
10.
高温超导限流电缆是一种新型超导电缆,充分利用了第二代高温超导体的优势,在电力系统正常和故障状态时分别表现低阻抗载流和高阻抗限流特性。高温超导限流电缆集成了超导电缆与超导限流器两种超导电力装备的功能。对于超导电缆和超导限流器,分别都有相关研究综述,而对于高温超导限流电缆缺乏系统性综述研究。从高温超导限流电缆的原理与结构出发,综述国内外有关高温超导限流电缆的研究现状,针对面临的技术问题进行分析。总结出高温超导限流电缆动态电流分布、载流限流瞬态变化过程、高温超导限流电缆接入到电力系统的新拓扑结构等关键技术和基础科学问题,获得了高温超导限流电缆未来的发展方向和趋势。 相似文献
11.
Arsalan Hekmati Mehdi HosseiniMehdi Vakilian Mehdi Fardmanesh 《Physica C: Superconductivity and its Applications》2012,472(1):39-43
The application of flat superconductor rings has been investigated in the structure of inductive shield-type high temperature superconducting fault current limiters, HTc-SFCL. A laboratory scale inductive shield-type HTc-SFCL has been designed and fabricated using flat superconductor rings. The fabrication process has been fully presented. YBCO powder has been used for the fabrication of superconductor rings. This fabrication process, being quite innovative, is introduced completely. The method of the trapped field measurement has been used for the critical current density measurement of the fabricated superconductor rings. The device with nominal current of 2 A was tested in a 30 V circuit. The SFCL successfully limited the fault currents of up to 10 times the nominal current to an approximately fixed value of 3 A. The voltage-current characteristic of the fabricated prototype has also been obtained and has shown compatibility with the fault current limitation results. 相似文献
12.
13.
A. Stenvall N. Magnusson Z. Jelinek G. Grasso I. Hiltunen A. Korpela J. Lehtonen R. Mikkonen M. Runde 《Physica C: Superconductivity and its Applications》2008,468(6):487-491
In this paper an electromagnetic system for a 200 kW MgB2 induction heater was designed to verify the feasibility of MgB2 superconductor in a DC induction heating system. The final master plan connects the electromagnetic design to the cryogenic and mechanical designs including the required measurement system. The electromagnetic design consists of conductor development, dimensioning the superconducting magnets and the quench protection system analysis. The coil system must guarantee appropriate heating distribution in the aluminium billet. The conductor has to fulfill the requirements of the current carrying capability required by the coil design. Furthermore, the conductor layout and constituent materials affect greatly to the coil stability in fault conditions. The coil behaviour during a fault was studied by quench simulations. The protection system design was based on the results of the quench analysis. 相似文献
14.
本文首先综述了大规模应用的超导磁体,依赖并推动铌三锡Nb3Sn导线技术进步,向更强磁场发展的趋势.着重分析了超高场14 T全身MRI磁体的挑战性技术.选择青铜Nb3Sn导线,采用Nb3Sn线圈和NbTi线圈相结合的混合结构,对14 T全身MRI磁体进行了电磁概念设计和热稳定性及失超保护仿真分析,并简要阐述了14 T全身MRI磁体在应力、接头和匀场方面的关键问题.根据分析结果认为:1)Nb3Sn导线是14 T全身MRI磁体需要面临的首要挑战性问题—作为最佳选择的青铜Nb3Sn导线,其现有产品的性能指标离14 T全身MRI磁体的要求尚存在有一定的差距;2)14 T全身MRI磁体的失超保护涉及线圈的铜超比设计、运行电流同线圈电感的协调配置、被动保护的分段策略和主动保护的失超触发控制以及主动屏蔽结构磁体在失超过程中的逸散磁场限制等多个十分复杂的环节,是最具挑战性的综合性技术. 相似文献
15.
We analyze theoretically adiabatic quantum pumping through a normal conductor that couples the normal regions of two superconductor - normal-metal - superconductor Josephson junctions. By using the phases of the superconducting order parameter in the superconducting contacts as pumping parameters, we demonstrate that a nonzero pumped charge can flow through the device. The device exploits the evolution of the superconducting phases due to the ac Josephson effect, and can therefore be operated at very high frequency, resulting in a pumped current as large as a few nanoamperes. The experimental relevance of our calculations is discussed. 相似文献
16.
17.
18.
因双根并绕堆叠结构的 YBCO 带材能够进一步增加设备承载电流密度, 被广泛应用于大型超导设备线圈绕制中. 本文研究了外层有包绕绝缘的双根并绕堆叠 YBCO 带材有缺陷情况下的失超传播特性, 应用有限元法方法, 建立了双根 YBCO 带材堆叠状态下失超仿真模型, 研究了存在不同缺陷的情况下双根堆叠超导带材的失超传播特性, 探索了堆叠带材在不同工作电流下传播速度(NZPV) 等参数的变化趋势, 同时探究了不同铜稳定层厚度下并绕堆叠带材失超传播规律. 结果表明缺陷区域面积增加以及铜稳定层厚度减小, 都将导致双根并绕堆叠结构的二代高温超导带材失超传播速度增加, 在带材上的温升增加, 增加失超的风险. 研究结果可以为超导设备安全稳定运行参数设置提供支持. 相似文献
19.
高性能高温超导带材在大型超导磁体装置上的应用已成为一种趋势,由于存在失超传播速度缓慢、失超检测信号微弱等不足,对失超保护设计提出很大挑战。本文基于液氮浸泡式双保护层的高性能ReBCO带材失超传播特性,采用一维热平衡方程建立失超传播速度的数学模型,通过增加失超源,检测热点温度与电压信号,探究液氮浴环境下的ReBCO带材在传输电流等不同参数下失超传播速度和最小失超能量的变化规律。结果显示:相同条件下,高温超导带材的失超传播速度与传输电流成正相关,最小失超能量与传输电流成负相关,且相比无保护层的普通高温超导带材,具有双保护层的高性能ReBCO临界电流和触发裕度均有提升。 相似文献