金属氧化物避雷器阻性电流测试仪校验装置

研制的金属氧化物避雷器阻性电流测试仪校验装置各指标满足规程要求,投入使用后,满足系统内对金属氧化物避雷器阻性电流测试仪校验的需要,使高压计量的手段更加完善。     

金属氧化物避雷器及其电气试验

1金属氧化物避雷器的试验GB50150--2006《电气装置安装工程电气设备交接试验标准》（以下简称《标准》）中对氧化物避雷器试验项目有如下规定：（1）测量金属氧化物避雷器及基座绝缘电阻;（2）测量金属氧化物避雷器的工频参考电压和持续电流;（3）测量金属氧化物避雷器直流参考电压和0．75倍直流参考电压下的泄漏电流;（4）检查放电计数器动作情况及监视电流表指示;（5）工频放电电压试验。     

氧化锌避雷器阻性电流测试仪标准装置的研制

课题研制的氧化锌避雷器阻性电流测试仪标准装置可用于开展氧化锌避雷器阻性电流测试仪的校准工作,项目涉及:全电流、阻性电流、容性电流、有功功率、参比电压、相位角、各次谐波电流分量。本文介绍了该标准装置的工作原理和核心技术,其中"平滑信号源的产生"和"可溯源性"设计具有创新性。     

一起110 kV避雷器参数异常事件分析

金属氧化物避雷器广泛应用于各电压等级的电力系统中,长期承受工频电压的作用,易出现受潮或老化现象,导致泄漏电流超标,严重影响电网设备安全稳定运行。通过对金属氧化物避雷器进行运行电压下交流泄漏电流测试,可以判断避雷器运行状况,当出现阻性电流增大情况时应加强监测并可结合红外测温进行进一步分析判断,如有需要可停电测试避雷器的1 mA下直流参考电压U_(1mA)和75%U_(1mA)下直流泄漏电流,判断是否有出现阀片老化或瓷质裂纹的可能。对问题避雷器解体检查可以查明避雷器故障的原因,验证前期试验结果,更好指导避雷器的制造和运行维护。     

一种新型的泄漏电流测试仪检定装置

介绍了SP11型泄漏电流测试仪检定装置,该仪器满足JJG 843-2007《泄漏电流测试仪》计量检定规程中对泄漏电流测试仪检定的要求。该仪器采用小电流交直流电子负载专利技术,在被测泄漏电流测试仪电源波动的情况下,仍能快速准确地进行检定。同时,使川高电压恒流源技术,可直接检定带模拟人体网络的仪器。实验结果表明,该仪器完全...     

谈防雷氧化锌避雷器带电测试

分析了氧化锌避雷器的等效电路,氧化锌避雷器的带电测试,主要是测量运行电压下的交流泄漏电流,其中包括金电流、阳性电流或功率损耗。给出了使用无间隙金属氧化物避雷器阻性电流测量仪器的使用方法及不同厂家仪器节电测试结果的比较     

大电流氧化锌避雷器阻性电流测试仪开发

为实现维护运行中的大电流氧化锌避雷器(MOA)阻性电流的现场试验,设计了一种在不停电情况下的大电流氧化锌避雷器阻性电流测试仪。开发了0～20mA的电流变送器和电压传感器,论述了阻性电流的测量方法及测试技术(三相同时测量防干扰技术、DSP技术、FFT算法等)。所设计的电流变送器和电压传感器将现场电流、电压信号经过简单放大滤波,由A/D转换后送入微处理器,然后由软件程序进行控制并计算后送液晶显示和打印机打印。对专门定制的特殊避雷器进行的实验室试验和现场试验结果证明,所设计的仪器测试数据准确、运行可靠。     

一起特别的1000 kV金属氧化物避雷器缺陷的发现与分析

针对避雷器运行电压下阻性电流增大,尤其随着季节不同阻性电流变化很大的现象,对避雷器进行了红外测温、停电试验和解体检查。找出了影响阻性电流变化的季节性因素,证明了阻性电流带电测试可以及时地发现金属氧化物避雷器(MOA)内部缺陷。对此次避雷器故障,还提出了今后避雷器状态检测应该注意的问题。     

金属氧化物避雷器阻性泄漏电流无线检测方法的设计

提出了一种测量金属氧化物避雷器阻性泄漏电流无线检测的新方法,该方法包括发送和接收两个装置。发送装置利用无线电理论,采集电网电压相位信号,并通过相应的电路将电网电压相位信号转换成脉冲信号进行调制后发送至接收装置。接收装置将接收到的电网电压相位脉冲信号进行解调后,与接收装置本身采集的避雷器全泄漏电流相位脉冲信号进行实时比较,得出电网电压和避雷器全泄漏电流的相位差,最后通过计算得出全泄漏电流的阻性电流分量,从而判断避雷器的性能。     

高压换流站交流侧避雷器在线监测系统的研制

针对高压换流站中的交流侧金属氧化物避雷器(MOA)设计一整套避雷器在线监测装置.装置包含避雷器泄漏电流(全电流)采集装置和PT电压信号采样装置.MOA监测装置向IED传送泄露电流幅值、泄露电流与参考相的夹角.PT采样装置向IED发送PT电压频率、谐波和电压转换成电流后与参考相的夹角.在监测IED内部计算得出泄露电流与母线电压的夹角,进而得出容性电流和阻性电流.最终通过IEC61850规约上送到变电站状态监测后台,实现整站交流避雷器状态的在线监测.在某避雷器有限公司的交流避雷器监测项目中的实际运行经验表明,设计的监测装置能够实现预期目标.     

A new approach to distribution arrester design

A new distribution-class surge arrester design concept is introduced. Replacing the conventional gasket-sealed porcelain housing is an epoxy/fiberglass-wrapped metal-oxide varistor disc module, assembled inside a flexible EPM rubber housing. This PDV (polymer distribution varistor) arrester design has the advantage of minimizing the free-gas volume inside the arrester, virtually eliminating concerns of moisture ingress due to seal pumping. In the unlikely event of arrester failure, the rubber-enclosed housing eliminates exploding porcelain fragments normally associated with standard distribution-class arrester designs. Performance questions related to assembling distribution arresters inside housings molded from polymer material are addressed     

Protection of Underground Systems Using Metal-Oxide Surge Arresters

The application of metal-oxide surge arresters on underground systems, and their advantages at the riser pole and system-open points, is shown for arresters now available as well as those anticipated based on current technology. Improvements in protective margins are shown for each type of arrester discussed, with both livefront and deadfront applications addressed.     

Metal-oxide surge arrester operating limits defined by atemperature-margin concept

The problem of ascertaining the absence of possible thermal runaway of metal-oxide surge arresters when they are used in applications requiring a very low protective level is addressed. An electrothermal model of arresters is used to predict the temperature-time profile of their active elements in severe (near thermal runaway) conditions. Experimental evidence is produced to validate the proposed method and justify a criterion for the operating limit of any arrester design. This operating limit is proposed as a maximum acceptable temperature for the arrester metal-oxide elements     

Maintenance of surge arrester by a portable arrester leakagecurrent detector

An instrument is described that detects leakage current without disconnecting the arrester ground wire. Better means were developed for detecting deterioration of a surge arrester than the existing appearance inspection, insulation resistance measurement, and leakage current measurement. The device measures only the in component of the current, which is proportional to the power loss. The change of the latter is the recognized measure of deterioration     

A Procedure for Estimating the Lifetime of Gapless Metal Oxide Surge Arresters for AC Application

The development of the gapless metal oxide (ZnO) surge arrester has presented the arrester engineer with new materials and an opportunity for new designs. This situation arises because the gapless surge arrester is electrically active throughout its lifetime whereas its predecessor, the silicon carbide arrester, was electrically passive being electrically isolated with gap structures. The prime consideration is one of reliably estimating the lifetime of a gapless ZnO surge arrester under continuous ac stress while maintaining the capability not only to limit surge voltages but also to absorb energy inputs resulting from lightning or switching surges and temporary overvoltages. In this paper we establish a procedure for reliably estimating the lifetime of gapless metal oxide surge arresters for ac application by incorporating the device characteristics into design requirements. This method is illustrated for metal oxide surge arrester elements that exhibit a predictable linear resistive current versus time1/2 behavior as a function of applied voltage and temperature.     

避雷器计数器综合校验装置

介绍了一种新型便携式避雷器计数器综合校验装置及其各功能实现,阐述了设计思路及方法,使避雷器计数器和监测器现场检测工具小型化和智能化。     

Increasing the reliability of MOV arresters

A shunt-gap module is designed for use in metal-oxide surge arresters to increase their tolerance to temporary system overvoltages and to lower the protective response. These are conflicting design objectives in current gapless metal-oxide-varistor (MOV) construction. Both objectives are fulfilled by the module, which, when incorporated into an MOV arrester, provides a 60% reduction in watts loss, a 20% lowering of the protective response, and a dramatic improvement in temporary overvoltage withstand. The module features a single shunt-gap assembly centrally located within two MOV disks. One shunt-gap assembly is incorporated in each 9 kV arrester proration     

氧化锌避雷器事故及运行检测方法探讨

通过对沙角A电厂沙鹏甲线线路阻波器设备内的无间隙氧化锌（ZnO）避雷器爆炸原因的分析,说明对ZnO避雷器实行在线监测的意义。在对各种金属氧化物避雷器在线监测方法进行比较和实例分析的基础上,指出红外测温在线监测和高压预防性试验相结合是值得推广和应用的ZnO避雷器运行监测方式。     

Multistress aging tests of polymer housed surge arresters

The combined stresses in multistress aging tests produce cumulative accelerated effects on polymer materials and surge arrester constructions that simulate typical service aging. The aging of polymer housed surge arresters is manifested by increased watts loss (internal, external or both), external flashover, or internal failure. Multistress testing is able to demonstrate deficiencies, with respect to aging, of surge arrester materials and designs, including the nature of interfaces in the insulation design. Therefore, multistress testing is believed to be a suitable test for evaluating the aging performance of surge arrester designs. Surge arrester housings made of materials other than silicone rubber are shown to age more rapidly and to require greater creepage distance than silicone rubber to maintain equivalent watts loss levels in multistress tests