高速限流保护开关的原理分析及应用探讨

对高速限流保护开关的原理接线和技术参数进行了说明,对高速限流保护开关与断路器的分断性能进行分析比较,并介绍了高速限流保护开关的几种应用方案。     

采用异步联网限制短路电流的实际应用和分析

500 k V主网短路电流超标问题已成为广东电网近年来运行最突出的问题之一。现有的运行措施可将超标站点短路电流暂时降低至安全水平,但电网整体的短路电流水平仍较高,且牺牲了部分系统安全可靠性,从长远来看通过直流背靠背异步互联限制短路电流是可行的解决办法。以2018年广东500 k V电网为研究对象,建立直流背靠背异步联网模型,从短路电流限制效果、系统可靠性等方面进行仿真计算,并与传统运行措施进行对比,可以得出,采用直流背靠背异步互联措施具有更好的限流效果和更高的安全可靠性,验证了该方案在短路电流限制方面的有效性和优越性。     

热敏电阻型一次限流消谐器的研究及应用

在中性点非有效接地系统中,电磁式电压互感器的铁磁谐振过电压是出现为最频繁、造成事故最多的一种内部过电压。研究表明,用热敏电阻制作消谐器,更适合消除PT铁磁谐振。同时,热敏电阻型一次限流消谐器还能够有效地防止因熔断器不能可靠熔断所引发的母线短路故障。     

Basic characteristics of high-Tc superconductor as a current-limiting element

This paper shows the basic characteristics of a current-limiting element for the power system using y-type high-T_c superconductor. (1) A YBa₂Cu₃O_x-type superconductor was produced. Its size was 4.7 × 1.5 × 47 mm. (2) Current I and voltage V were measured under the low temperature of 50 to 100 K. (3) The flow resistance and the resistance of the element were defined and evaluated from the I - V characteristics obtained under the conditions of lower temperature than the critical value T_c, and larger current density than the critical value J_c. (4) The resistance value change due to temperature rise also was evaluated under the larger current than the critical current. (5) A schematic calculation was tried for practical use in some system condition.     

The application of current limiting to distribution circuit protection

Many electric utility systems are reaching the point where available short-circuit currents, during severe faults, exceed the interrupting capability of available circuit interrupters of conventional types such as circuit breakers, distribution-circuit reclosers, and expulsion fuses. The needs are being met by the use of current-limiting fuses to protect individual distribution transformers or, sometimes, groups of distribution transformers, but there are difficult problems of coordination. The current-limiting fuses are not inherently capable of covering the full range of short-circuit currents, so that they must be used in addition to, or in combination with, interrupters of other types. This paper studies these problems in depth and makes recommendations for even wider use of current-limiting fuses to achieve more effective protection of the entire distribution system, including protection of distribution feeders at the substation. This approach also provides effective preventive measures to inhibit disruptive transformer failures which have become a severe problem with increasing short-circuit-current capability.     

磁偏置超导故障限流器限流响应模型与并网运行研究

针对电网短路故障限流问题,提出一种新型磁偏置超导故障限流器(SFCL),采用超导无感组件、双分裂电抗器支路两级限流的运行方式,具有自触发、分级故障限流、快速自我恢复等优点.应用MATLAB/Simulink软件,搭建了含磁偏置SFCL的10 kV电网线路仿真模型,提出超导限流组件磁热耦合特性的物理建模方法,并对0°和90°短路故障角下的SFCL并网限流效果进行瞬态仿真和比较.仿真结果表明,在电网0°和90°不同故障短路角电流冲击下,SFCL在首半波中的限流率分别为36.45％和45.89％,随后第2个半波的最大限流率达到78.58％,限流电阻在90°短路故障角下的变化率是0°短路故障角下的1.75倍,实现了较快的限流动作响应和显著的分级限流效果.最后实验验证了磁偏置超导限流技术的可行性.     

Breakdown of YBCO thin films during current limiting and methods of improving current limiting performance

We performed fault current limiting tests using YBCO thin films and investigated the reasons for their breakdown during current limiting. There were two patterns of film breakdown. One occurred immediately after current limiting and the other occurred during current limiting. In film breakdown, the quench propagation speed showed almost no change with increasing energy consumption per unit time, but the energy consumption per unit area increased with increasing energy consumption per unit time. Therefore, local areas of the film reached the melting point and arcing occurred. It is therefore concluded that the performance of the films can be improved by decreasing the energy consumption per unit time. Connecting a parallel capacitor to the film in order to limit the energy consumption per unit time is proposed and tested as a measure to improve the current limiting performance of thin films. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 20–27, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20709     

新型混合型限流断路器在直流电力系统中的限流特性研究

针对直流电力系统高di/dt短路电流难以分断的问题,开展了基于高速斥力开关的混合型限流断路器在直流电力系统中的应用研究.对限流断路器的工作原理、参数设计以及高速斥力开关的动作特性进行了分析,采用EMTP仿真分析了限流断路器在不同短路电流上升率下的限流特性.仿真结果表明限流断路器可将预期100 kA、时间常数5 ms的直...     

基于灵敏度分析的限流方案优化决策方法

考虑限制短路电流与提高系统稳定性的相互制约关系,提出一种基于灵敏度分析的限流方案优化决策方法。通过分析各种限流措施对阻抗矩阵元素的影响,推导各种限流措施与超标站点自阻抗的灵敏度关系,提出一种考虑限流措施灵敏度的支路筛选策略。以总投资成本最小和短路容量裕度最小为目标,应用自适应混合粒子群优化算法寻找限流方案集。基于层次分析法建立综合评价模型,应用模糊综合评价算法对限流方案集进行系统性定量决策。实际系统仿真结果表明该方法能够快速获得优化决策方案。     

复杂多端柔性直流电网源网限流设备协同优化配置

利用源网限流设备协同优化配置解决复杂多端柔性直流电网的故障电流抑制难题,成为相关领域的研究热点.首先,结合模块化多电平换流器(MMC)与电网的耦合程度,提出适用于复杂多端柔性直流电网的区域划分原则,以提高多端柔性直流电网限流设备参数优化的计算效率;然后,根据各区域的限流需求,结合MMC、直流变压器、限流电抗器及故障限流...     

CLIP限流保护器在中压配电系统应用

1 工作原理和基本参数 1.1 工作原理 CLIP限流保护器(简称CLIP)属于转换型限流保护装置TCL(Triggered Current Limiter),是一种具有大持续载流能力的高速切换开关,俗称组合式限流熔断器.在欧洲、加拿大、美国和世界各地应用甚广.     

Calculation method for estimating thermal impedance for pulse current of power semiconductor devices

Contents The described method is valid for arbitrary wave forms of the constant pulse current and for all diode, transistor and thyristor family devices whose thermal circuit can be modelled electrically by the serial connection of resistor-capacitor RC-pairs and whose forward characteristic can be approximated by slope resistance and threshold voltage. Temperature dependence of the device's thermal circuit parameters and temperature dependence of the forward characteristic parameters were not taken into consideration. The method enables an estimate to be made of the influence of current amplitude on the value of thermal impedance for pulse current.

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Eine Rechnungsmethode zur Bewertung der thermischen Impedanz für Impulsstrom von Leistungshalbleiterkomponenten

Übersicht Die vorgestellte Methode ist für beliebige Impulsstromform und zwar für alle Komponenten aus den Dioden-, Transistoren- und Thyristoren-Familien geeignet, deren thermischen Kreis man durch Serienschaltung von RC-Gliedern elektrisch modellieren und die Durchlaßkennlinie durch Ersatzwiderstand und Schleusenspannung approximieren kann. Die Temperaturabhängigkeit der Parameter der Durchlaßkennlinie der Komponente wird nicht berücksichtigt. Die Methode erlaubt eine Abschätzung des Einflusses der Stromamplitude auf die thermische Impedanz für Impulsstrom.

     

Enhancing reliability of electric power systems using superconductor devices

The possibility to improve the operation regime and the reliability of electric power systems using superconductor devices is considered.     

Pulsed field losses and coupling current loop in a large‐current superconductor

Pulsed field losses in a short sample (445 mm length) of 46‐kA Nb₃Sn cable‐in‐conduit conductor of superconducting magnet for the fusion experimental reactor “ITER” are measured by a calorimetric method. The coupling time constant between strands is obtained as 30 ms through pulsed loss. Based on this time constant and interstrand conductance measurement, it is expected that there is a coupling current loop length of about 400 mm, which is longer than half the fabrication twist pitch in the fourth cabling stage. A geometrical calculation on several‐stage cabling shows this value to be reasonable. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 142(4): 27–33, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10088     

Studies of characteristics and design of superconducting fault current limiter with adjustable trigger current level in current limiting operation

Superconducting fault current limiters (SCFCLs) are expected to improve not only reliability but also stability of power systems. To introduce an SCFCL in a power system, various specifications such as trigger current level, impedance in current limiting operation, recovery time, and so on are necessary. Fault analyses point out that accuracy of the trigger current level is necessary. Therefore, an SCFCL of a transformer type with adjustable trigger current level was proposed and manufactured. Using the trial SCFCL, adjustability of the trigger current level was confirmed. It is found that the SCFCL has good limiting and recovery characteristics. In this paper, characteristics of the SCFCL are considered from a design point of view. Most of the specifications necessary for design depend on the characteristics in current limiting operation. Therefore, the characteristics of the SCFCL in current limiting operation are discussed. It is shown that this kind of SCFCL has good property for easy design, and its design principle is summarized. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(3): 30–38, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10054     

断路器新型限流电路的探讨

介绍在断路器中使用的新型限流电路 ,其满足了电力系统中限流技术的要求 ,大大提高了断路器的可靠性和分断能力 ,是很有前途的限流方案     

断路器新型限流电路的探讨

介绍在断路器中使用的新型限流电路,其满足了电力系统中限流技术的要求,大大提高了断路器的可靠性和分断能力,是很有前途的限流方案.     

混合式限流断路器的研究与发展

电力电子技术的进步与新型器件的出现为电力系统的发展提供了新的机会.概括了目前混合式限流断路器(HCLCB)的基本工作原理及其在国内外发展状况,详细介绍了基于不同器件的HCLCB的拓扑结构,诸如自然换流式及强迫换流式HCLCB,并分析了相应的技术特点,同时还从机械结构及故障电流检测的角度阐述了HCLCB设计要点,希望能为HCLCB的设计提供参考.     

混合式限流断路器的研究与发展

电力电子技术的进步与新型器件的出现为电力系统的发展提供了新的机会。概括了目前混合式限流断路器(HCLCB)的基本工作原理及其在国内外发展状况,详细介绍了基于不同器件的HCLCB的拓扑结构,诸如自然换流式及强迫换流式HCLCB,并分析了相应的技术特点,同时还从机械结构及故障电流检测的角度阐述了HCLCB设计要点,希望能为HCLCB的设计提供参考。