SF6自吹断路器燃弧过程压力温度的模拟计算及分析

本文以喷嘴喉部截面为界,视储压室和排气室为压力和温度各自均一的两个空间,将储压室容积、喷嘴半径、排气室与储压室的容积比等主要结构参数及与燃弧过程相关的分闸速度、初充气压、开断电流、弧柱电位梯度、气体对电弧能量的吸收系数等用可代参量表示.联解储压室和排气室变质量气体状态方程及燃弧过程动态能量平衡方程,模拟计算了不同起弧相角下压力、温度和吹弧压力比的变化过程。分析计算所得数据将有助于断路器灭弧室的设计。     

SF_6断路器喷口烧蚀性能的试验研究

本文对SF_6断路器喷口耐电弧烧蚀性能进行了试验研究,拟合出喷口烧蚀与开断电流,燃弧时间和电弧能量的关系曲线,分析了开断电流和燃弧时间对喷口烧蚀的影响,试验结果表明国产喷口取代法国喷口是可行的。     

Series Capacitor SF-6 Bypass Interrupter

Series capacitor banks on transmission lines ave two types of bypass switches; high-speed switches located on the insulated capacitor platforms for operation, and manually-operated line switches to isolate the bank for maintenance. Air break switches used for maintenance bypass on 345 kV series capacitors could not successfully transfer line current without heavy arcing. An SF-6 interrupter like that manufactured for transformer protection, was selected for a simple retrofit replacement.     

Comparison of CFD tools for SF/sub 6/ self-blast circuit breaker development

Computational fluid dynamics (CFD) simulations of high voltage SF/sub 6/ self-blast circuit breakers (CBs) have been successfully established as tools for development and design. Two different approaches modeling the physical interaction between switching arc, radiation, ablation, and gas flow are presented. Radiation is the main energy exchange mechanism; therefore, attention is paid on validation of the applied radiation modeling. A validation is given with respect to the pressure rise inside the thermal volume in comparison to the measured pressure during the test of a self-blast CB according to IEC56.     

一起500kV SF_6断路器爆炸事故分析

针对兴仁换流站发生的一起500kV SF6断路器爆炸事故,根据SF6断路器的灭弧室结构、开断原理及动作过程,结合现场实际情况,分析了事故的各种可能因素。确定了该起事故的原因为T型机构箱内转轴的轴承漏装,多次分合后转轴逐渐移位,并磨损了传动机构的1个销子,最终导致销子脱落;断路器合闸后弧触头不能接触,出现稳定短电弧导致灭弧室内气体发热,压力升高,灭弧室发生爆炸导致电网短路事故。对制造厂的质量控制提出了建议,以避免类似事故发生。     

真空灭弧室中屏蔽罩电位动态测试及分析

本文通过测量真空灭弧室中屏蔽罩电位与电弧电压和恢复电压关系的动态变化波形，探讨真空灭弧室在短路电流分断过程中，真空电弧的燃弧规律和弧后介质强度恢复规律。在试验结果的基础上，对真空灭弧室屏蔽罩电位与触头间电压的动态关系进行了数学推导，从理论上分析了屏蔽罩电位的变化规律，证实这是一种研究真空灭弧室性能的可行方法。     

浅谈断路器近区故障的容量开断

介绍开断近区故障(SLF)时恢复电压的计算和灭弧室在不同燃弧时间下的理论分析。     

Relationship between current waveform just before current zero and interruption ability of high‐speed VCB

A high‐speed vacuum circuit breaker which forces the fault current to zero was investigated. The test circuit breaker consisted of a vacuum interrupter and a high‐frequency current source. A vacuum interrupter with an axial magnetic field electrode and a disk‐shaped electrode was tested. The arcing period of the high‐speed vacuum circuit breaker is much shorter than that of a conventional circuit breaker. The arc behavior of the test electrodes immediately after the contact separation was observed by a high‐speed video recorder. The relation between the current waveform just before the current zero point and the interruption ability was investigated experimentally by varying the high‐frequency current source. The results demonstrate the interruption ability and the arc behavior of the high‐speed vacuum circuit breaker. Effective current interruption is made possible by a low current period just before the current zero point, even though the arcing time is short and the arc is concentrated. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(2): 20–27, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20915     

纵磁真空灭弧室的弧后电流

测试和研究了纵磁灭弧室中真空电弧弧后电流的变化与开断电流和电极开距之间的规律,得出了使弧后电流快速上升的转折电流,它表征了燃弧期间开始出现阳极斑点.     

气吹灭弧室的斜坡电流开断特性研究

本文介绍了用斜坡电流方法进行SF_6气吹灭弧室的开断特性的研究,其等值条件是电流零点以前的下降斜率相等。与工频电流的开断相比较,以极限的(dv)/(dt)与(di)/(dt)关系表示的开断特性,以及零前若干微秒的电弧电导变化,在(di)/(dt)<20A/μs以下,即相当于工频电流半波里喷口没有出现严重堵塞的条件下,两种开断性能没有很大差别,简化的斜坡电流可以用以代替工频电流进行开断特性研究。但在喷口出现严重堵塞现象之后,工频电流开断特性恶化。     

550kV/50kA单断口断路器的开发

通过对550kV/63kA双断口断路器和363kV/50kA单断口断路器技术加以改进,利用计算机解析技术,提高了额定SF6气体压力和分闸速度,对弧触头和喷口形状进行了改进,优化了灭弧室结构,从而开发出550kV/50kA单断口罐式断路器样机。该样机分别在国家高压电器质量监督检验中心和KEMA实验站完成了绝缘试验及容性电流、大容量开断等试验项目。550kV单断口断路器所有电气性能得到了确认。     

SF_6断路器灭弧室内电场的数值分析

采用8节点等参元法,对SF_6断路器灭弧室内断口间的电场进行了详细的计算。在此基础上分别对喷口,最大开距,主触头结构,主、弧触头间结构的配合等参数的改变对断口间电场的影响,进行了讨论。整个计算软件具有通用性强,使用方便,易于处理复杂边界,前处理简单,后处理形象、直观等优点。     

基于旋转灭弧的SF6气体分界负荷开关的研究和应用

介绍了一种基于自力消弧即旋转灭弧方式的新型SF6气体分界负荷开关,其原理是利用了主回路流通电流产生的电磁力来灭弧,采用与以往分界负荷开关不同的接地检测方法,即方向性接地检测法来判断界内发生的故障并予以保护,可极大地减少由于线路故障导致的停电,缩短用户停电时间,提高供电可靠性。将该分界负荷开关应用在某变电站10 kV线路上,并设计了1套由电力监管计算机、指定手机、遥控器、掌上电脑、控制器等组成,依靠无线通信实行数据传输的监控系统。经过8个多月的运行统计,应用该系统变电站故障次数较前两年明显减少,接地保护故障与相间短路故障得到了有效抑制,提高了重合闸成功率。     

炸气流灭弧性能及应用效果分析

为了研究爆炸气流灭弧防雷间隙的灭弧特性,通过对该灭弧防雷间隙的爆炸气流工频灭弧试验,得出了该灭弧防雷间隙的工频续流电弧在4 ms时间内即被强气流吹灭,气流维持时间大于6 ms。同时建立链式电弧模型和Mayr电弧模型分别对电弧所受气流压力和爆炸气流灭弧防雷间隙的能量散失特性进行研究,并利用力学软件ANSYS14.0对强气流干扰下的电弧能量进行仿真分析。从结果分析可知电弧在气流强压力作用下能量迅速耗散,并在极短时间内被截断熄灭。在实际运行中,降低雷击事故率97%,灭弧效果明显。     

一种真空断路器真空度在线检测新方法

详细介绍了一种真空断路器真空度在线检测的新方法,其真空灭弧室经过特殊设计,使用内置式双波纹管灭弧室,利用外界气体压力和灭弧室内腔自闭力的平衡原理,当真空灭弧室有漏气时（外界大气压进入）,引起自闭力的变化导致压力元件和位移传感器输出数据发生变化,从而使真空断路器本地闭锁并报警,同时经通用分组无线电业务（GPRS）网络也可实现远程监测报警.采用内置式双波纹管检测技术的真空断路器及其在线检测装置在现场应用情况良好,表明文中特殊设计的真空灭弧室具有推广实用价值.     

500 kV输电线路钢化玻璃绝缘子集中自爆现象分析

针对500kV输电线路上钢化玻璃绝缘子集中自爆现象的多次发生,举例阐述了钢化玻璃绝缘子集中自爆缺陷情况,并对2000年至2004年5条500kV输电线路使用160kN玻璃绝缘子发生的自爆进行统计。分析了钢化玻璃绝缘子自爆及其不易发生掉串事故的原因,并提出了钢化玻璃绝缘子检修中可用钢丝球擦拭确保清扫质量,以及对故障闪络后钢化玻璃绝缘子的处理方式。     

雷电过电压引起灭弧室爆炸过程暂态分析

为了定量描述雷电过电压引起断路器灭弧室爆炸的全过程,以提出相应的预防措施,利用EMTP电磁暂态程序,以国内某220 kV电力系统为例,对雷击杆塔后断路器断口处的雷电过电压进行了计算。同时,依据热力学原理和气体状态方程,对断口燃弧产生的能量及由此引起的灭弧室压力升高进行了计算。最后,研究了燃弧时间和雷电流幅值对电弧能量及灭弧室压力的影响,提出了预防灭弧室爆炸的措施及绝缘配合相关意见。研究表明,灭弧室爆炸是由于电弧能量使其内部气压过大造成的,减小燃弧时间可降低电弧能量。雷电流的大小不是灭弧室爆炸的决定因素,而是其断口击穿的触发条件。在变电站进出线处安装避雷器可有效降低雷电冲击电压的幅值。     

Determination of gas pressure in vacuum interrupter based on partial discharge

Partial discharge characteristics in air under a low vacuum region were studied to develop a diagnosis technique to determine the gas pressure in a vacuum interrupter. The pressures were set at from 1.3 Pa to 2.6 kPa in order to simulate the leakage of gas into the vacuum interrupter. The structure of the vacuum interrupter, the measurement and the circuit construction for the experimental setup were described. The measurement of partial discharge occurring inside the vacuum interrupter was performed with a current transformer, intensified charge coupled device (1CCD) camera and photomultiplier tube. The measurement of partial discharge light intensity with a photomultiplier tube was more sensitive compared with that measured with a current transformer. From this result, an attempt has been made to distinguish the pressure below and above 260 Pa on the basis of the rise time and peak intensity of discharge light pulses. A relatively longer rise time (2 mus) with a smaller magnitude (less than 0.5 mA) was attributed to a Townsend-like discharge at pressures below 260 Pa, while a sharper rise time ~(10-100 ns) with a larger magnitude (greater than 1 mA) was characterized as a streamer-like discharge above 260 Pa. In addition, the estimation of gas pressure in a vacuum interrupter was made based on phase-resolved discharge characteristics utilizing an artificial neural network.     

Pressure Rise due to SF6 Arcing and Energy Balance in a Closed Container

From an environmental viewpoint, when carrying out internal arc tests on SF₆‐insulated power equipment, it is necessary to prevent SF₆ from being released into the atmosphere or to replace SF₆ with air in accordance with IEC standards. However, the pressure rise and the thermal effect of the hot gas exhausted during arcing when testing in air are still considerably different from those for testing in SF₆. Thus, it is necessary to propose a specific procedure to replace SF₆ with air and to select appropriate parameters for the tests. Therefore, it is desirable to clarify the equivalent conditions causing these phenomena both experimentally and analytically. In this paper, we describe the effect of the charged gas pressure in a closed container on the pressure rise due to air and SF₆ arcing and the ratio of the arc energy to the energy contributing to the internal pressure rise () from an experimental viewpoint. Additionally, to research the energy balance resulting from SF₆ arcing in the container, the energy balance is discussed on the basis of chemical reactions, radiation, and the melting and vaporization of the electrodes. It is found that the maximum pressure rise increases for both gases upon increasing the gas pressure from 0.1 MPa to 0.4 MPa. Subsequently, good agreement with the energy balance was obtained under reasonable assumptions by taking account of the energy components related to the chemical reactions, radiation, and the melting and vaporization of the electrodes. The ratio of the radiation energy loss to the total consumption energy increased upon increasing the charged gas pressure.     

10 kV高压开关柜的故障在线检测方法

为提高１０ｋＶ高压开关柜的可靠性，提出了母线连接处温度、动作时间、弹簧储能时间与真空灭弧室等真空度测量方法。