断路器分闸过程中辐射电磁波测试研究

为了解决现有断路器拒动现象造成的工矿企业非计划停电问题,本文分析了现有试验方法无法直接检测断路器触头灭弧性能具体原因,提出一种利用断路器分闸过程中辐射电磁波信号反推断路器灭弧性能的检测技术。同时,通过搭建模拟试验平台,完成开断电压、分闸速度、负荷类型和触头烧蚀程度对断路器分闸测试的影响分析,揭示了上述四种因素与断路器分闸过程中辐射电磁波信号的关联性,并给出如何利用电磁波分析断路器触头烧蚀程度对其灭弧性能影响的测试建议。在此基础上,针对断路器电压等级低、离地距离近的特点,开展现场非接触式断路器灭弧性能测试,结果表明本文所述方法具有很大的推广价值。     

瞬态过电压模拟用的真空断路器的统计模型

用新型电力ＴＡＣＳ模型通过ＥＭＴＰ研制了中压真空断路器的统计模型。该模型包括电弧电压特性、已知ｄｉ／ｄｔ的平均截流值的计算、绝缘击穿电压特性、触头分离动态特性、高频熄弧能力的概率和高频电流过零概率。研究了断时间的影响并给出了专门网络结构的预期的瞬态过电压的统计估计。介绍了开断时间和过电压的关系。除了这些结果之外，文中说明了构成配电网络的所有元素的ＥＭＴＰ的模拟技术并对真空断路器模型特性的予以认证。     

真空断路器的过电压及重燃特性

真空断路器具有优异的开断特性和绝缘恢复性能．，并且能开断不稳定电弧产生的叠加在线路频率电流上的高频电流。开断这些高频电流也称为关键截流，当断路器分闸时它也能引起多次重燃，并在某些电网中引起严重的上升电压。为了估算这种瞬态电压的几率，研制出了一种ATP／EMTP数字化断路器模型。此模型说明了断路器的燃弧时间、截流、绝缘性能和灭弧能力的随机性。本文对48种具有代表性的断路器(4种绝缘强度、4种熄弧能力及三种不同时间范围的分闸)进行了分析并得出了结论。     

真空开关管开断能力随触头几何形状变化的关系

真空断路器触头的形状和大小各不相同,关于它们开断能力的系统研究已有报道。各种几何形状的电扳可产生自激的横向或轴向磁场(其强度与电流有关),其开断电流的极限值也因而确定。令人尤感兴趣的是电弧的外观(发散或集中,体现在电弧电压的波形中)、触头的抗腐蚀性能以及电弧运动对灭弧能力的影响。Weil—Dobke 综合试验电路,其最大电流为60kA(有效值),电压状态与20kV 的电力系统相对应。单极开断试验的实验就是应用此线路及一台可拆卸的真空良装置进行的。实验的结果表明:开断能力总的说来随触头直径的增大而提高。横向磁的结构为电弧在整个使用寿命期间保持良好运动状态创造了条件,因而使性能得到改善,但轴向磁场结构的触头所得到的结果最好。     

横磁作用下直流真空开断中触头侧部燃弧空间的影响规律研究

随着直流电网的不断发展，对直流开断技术的要求进一步提高。相较于传统的气体电弧直流开断，真空电弧直流开断具有电寿命高、燃弧空间封闭、介质恢复速度快等特点，但是传统真空电弧电压低，需要通过横向磁场的作用，提升电弧电压完成直流真空电弧的开断。本文通过实验研究了横向磁场作用下不同触头侧部燃弧空间(即触头侧部边缘与真空灭弧室屏蔽罩之间的空间)与开断电流时的开断特性，获得了触头侧部燃弧空间宽度11～41 mm范围内对直流真空开断特性的影响规律。     

浅谈真空断路器开断电机的保护措施

真空断路器在电力设备中广泛应用,具有灭弧电压低、灭弧能力强、触头损耗小、开断次数多等优点。但真空断路器在开断过程中存在操作过电压问题,所以使用中必须采取适当的保护措施,有效抑制或减轻工或危害,更好地发挥其使用效果。     

电动机回路中低过电压真空断路器的三相共同截流产生的估计方法

研究出了一种考虑开断参数：截流、电弧寿命时间和绝缘恢复特性的真空断路器（ＶＣＢ）操作过电压产生的模拟方法。实际电机开断试验获得的概率特性，证实了该方法的适用性。发现触头和触头分离速度，特别是触头起始分离速度是最有影响的因素。     

真空中延时击穿的研究

我们用一个高清晰度的双筒摄像机（ICCD），通过一些试验来研究真空断路器的延时击穿现象，延时击穿可以引起电弧重燃，导致开断失败，这种开断失败比较少见，它可以由好几种机理产生，本文介绍了研究这种特殊现象的方法，并且展示了击穿发生的初始阶段电弧的图象。     

双极纵磁场的真空开合触头的特性

纵磁场触头可提高真空断路器的开断能力，局部纵磁场的结构原理依设计而有所不同。对于单极纵磁场的方向在整个触头区域的内是相同的。对于双极结构来说其纵磁场方向在磁场内有一个极性改变。为了表示双极给磁场触头系统的特征并试验其开断性能，进行了调查。双极磁场对电弧发展和热应力的影响通过高速摄像从５０ＨＺ高频电流激发的描述，此外，通过有限元素程序对某个三维纵磁场进行了模拟。从５０ＨＺ高频电流激发发的时变纵磁场的     

大电流真空电弧中阳极烧蚀过程的研究进展

在大电流真空电弧开断中阳极触头的烧蚀情况将决定开断的成功与否，掌握高电压等级真空开断关键技术需要深入理解真空电弧阳极烧蚀机理。本文对国内外关于阳极烧蚀的研究进行了综述，包括阳极放电模式的分类及特点、阳极表面温度及熔融触头运动的实验测量以及阳极烧蚀数值模拟，在此基础之上总结了触头材料对阳极烧蚀的影响，对大电流真空电弧阳极烧蚀研究的未来发展方向提出了建议。     

Arc root mobility on piezoelectrically actuated contacts in miniature circuit breakers

A novel contact opening mechanism has been developed using a piezoelectric actuator to open the contacts in a low contact opening velocity circuit breaker. The arc control on the contacts is critical for successful current interruption (10/sup 3/-10/sup 4/ A) in low voltage (<250V) devices. Previous work has shown how arc root commutation from the contact region into the arc chamber is affected by arc chamber materials, contact materials and the gap behind the moving contact for contact velocities between 1ms/sup -1/ and 10ms/sup -1/. This work is extended using a commercially available piezoelectric actuator to open the contacts. Contact opening speeds are assessed and the arc root mobility is characterized under this operating regime. A flexible test apparatus and solid-state high-speed arc imaging system are used to gather data on the arc root during the opening of the contacts. New experimental results are presented on the anode and cathode root velocity and arc root motion in an arc chamber with piezoelectrically actuated contact opening. These results can be used to improve the design of high current low voltage circuit breakers suitable for piezoelectric actuation.     

真空断路器的EMTP-ATP电磁暂态仿真教学研究

基于EMTP-ATP的真空断路器电磁暂态仿真设计是“复杂电气工程系统设计”教学中的重要内容，教学难点在于截流值、介质动态绝缘强度及高频熄弧能力的准确表征，由于该过程涉及电路原理、数理统计以及计算机编程等学科知识，其仿真建模十分抽象，学生理解较为困难。本文开展基于EMTP-ATP的真空断路器电磁暂态仿真，有助于学生更好地理解断路器分合闸的物理本质，使其更直观理解断路器重燃以及预击穿过程。     

SF6高压断路器检测维护策略研究

SF6高压断路器是利用六氟化硫气体作为灭弧介质和绝缘介质的一种断路器,由于SF6气体的优异性能,使其在应用过程中具备明显的优势.鉴于此,本文主要分析SF6高压断路器的检测维护策略.     

Contact material and arc current effect on post-current zero contact surface temperature

Optical radiation measurements of contact surfaces were made after current-zero of a high-current (>10kA/sub p/) arc, to determine how much the contact surface temperature at and after current zero was affected by a change in contact material and arc current. Contact surface temperature was measured for different types of "typical" contact materials (AgW and AgC) commonly used in molded case circuit breakers (MCCBs). The average temperature at the contact surface was measured by using photodiodes in conjunction with a narrow band filters and long-range microscope. A 250-A rated MCCB was modified, with renewable chamber walls and contacts, and used as a test bed to insure that these results can be directly applied to MCCBs in the 125 to 250-A range. Uniform and repeatable arcing conditions were maintained by using an electronically timed capacitor bank source, timed contact part, and a well-maintained arc chamber. Along with other important engineering properties of the contacts (arc erosion, temperature rise), this data can be useful for selecting contacts for circuit breaker applications.     

The energetics of gas flow and contact erosion during short circuit arcing

The processes governing the movement of short circuit arcs in circuit breakers are complex and variable and the detailed understanding of these processes is incomplete. This paper presents a new approach to our understanding of the short circuit arcing process by concentrating on the bulk thermal behavior and energetics of the arcing and gas flow during contact opening. It is shown how considerations of the arc power and the heating and vaporization of the contact material can be used to examine the flow of gas through the arc chamber and the erosion of contact material. Experimental data from a flexible test apparatus and arc imaging system along with measurements of pressure and arc current and voltage are used as the basis of the analysis. It is demonstrated how the air initially present in the arc chamber will be rapidly expelled from the arc chamber to leave an arc burning in the products of contact volatilization. Data on mass and volume flow rates are presented as well as estimates of the gas velocity in the contact region. These data provide information on the nature of the gas flow in the arc chamber as well as contact erosion during the arcing process. Arcing conditions of interest are short circuit faults (10/sup 3/-10/sup 4/ A) in low voltage (220-380 VAC) circuit breakers.     

Voltage-current characteristics of breaking arc at constant opening speed in the air

Voltage-Current (VI) characteristics of breaking arc between electrical contacts have been investigated for several contact materials (Au, Ag, Cu, Pt, and Ni). The purpose of this paper is to investigate the VI-characteristics and minimum arc voltages of the breaking arcs that occur between slowly opening (1.0 cm/s) contacts, and compare these results with those of Holm. Experimental circuit is resistive, which has 5-/spl Omega/ circuit resistance. Experiments were carried out in the air at atmospheric pressure for supply voltages 30, 42, and 54V. The time evolutions of arc voltage, arc current and gap length were measured simultaneously. The VI-characteristics and minimum arc voltages were obtained from those measured values. The results showed that minimum arc voltages for each contact material (Au, Ag, Cu, Pt, and Ni) agreed with those of Holm. On the other hand, VI-characteristics of Au, Ag, Cu, and Pt contacts agreed with those of Holm, but VI-characteristics of Ni electrical contacts disagreed with those of Holm. The difference for VI-characteristics between Ni electrical contacts and the others was because of lower electric field of the arc column for the case of nickel electrical contacts.     

发展高电压等级真空断路器的技术问题探讨

本文对发展高电压等级真空断路器的关键技术问题，如触头材料，灭弧室耐压特性、电弧特性、弧后特性、波纹管设计及触头运动特性等进行了探讨，可为高电压等级真空断路器的设计提供依据。     

Anode and cathode arc root movement during contact opening at highcurrent

This paper presents experimental research into the behavior of short circuit break arcs ignited between opening contacts. The investigation is applied to arc chamber geometries commonly used in miniature circuit breakers (MCB). The movement of the anode and cathode roots are individually plotted from optical data, allowing the relative motion to be compared. The effect of a range of MCB configurations on the arc root motion has been investigated. The experiment was configured so that the fixed contact was always the cathode. The results show that the two are roots do not move away from the contact region simultaneously. Often the cathode root moved off the fixed contact and away from the contact region before the anode root commutated from the moving contact. The delay in anode root commutation leads to a delayed cathode root movement. These events are explained in terms of arc root emission processes     

论低压开关中永磁控制技术的应用

为了克服传统低压开关电动控制系统中所存在的诸如接触器主触头被烧、短路情况下断路器无法正常将电路分断、电机保护功能难以充分发挥等问题,可以通过永磁控制技术的应用加以实现.本文重点就低压开关的电磁控制技术进行探讨,以供参考.     

A measurement on electromagnetic noise and change of surface inarcing electric contacts

The authors have observed the relationship between waveform of electromagnetic noise and change of surface for opening Ag-Pd electric contacts. In case of Ag-Pd electrodes, continuous noise is observed in the whole period of arc discharge in both current polarities. Fluctuations of are voltage and noise are large in the middle part of arc discharge duration. The noise decreases in the later half. The authors proposed a classification of noise waveforms and pattern of surface changes. As a result, patterns of noise waveform and changes of electrode surface at various circuit conditions are classified into three categories. In this paper, the authors showed the correlation between pattern of noise waveform and the change of electrode surface