Modeling Rogowski Coils for Monitoring Surge Arrester Discharge Currents

Rogowski coils(RCs)are widely used to measure power or high frequency currents based on their design.In this paper,two types of RCs that are circular(traditional)and cylindrical shapes wound using wire covered by varnish are constructed.This construction is carried out to be suitable for monitoring the discharge current of the surge arrester installed in the distribution system.Concerning high frequency RC modeling for both types considering transfer function is introduced.Self-integrating for both types is attained.Therefore,the experimental tests using function generator for both coils are carried out to identify the parameters of the transfer function representing the introduced model.The measured signals for current and induced voltages are denoised for the parameter identification process.The denoised process is achieved using the MATLAB code‘wdenoise’while the parameters are estimated using the system identification toolbox.Verification of the proposed model is achieved using experimental results for the two coils.The sensitivity of the two coils is investigated based on the induced output voltage.The application concerning the two coils for monitoring the discharge current of the surge arrester is done.The results confirm the accuracy of the introduced RC model,as well as the performance of the cylindrical shape,is better than the traditional one.The simulation is carried out using MATLAB and ATPDraw programs.

SEPW-the Cradle of Surge Arresters and Fuses in China

Shanghai Electric Porcelain Works (SEPW), a subsidiary enterprise of the SEC (Group), is specialized in manufacturing highvoltage surge arresters and fuses as main products, as well as some high-voltage insulators, wall bushings and disconnecting switches for power transmission & distribution systems. In fact, SEPW is

Leakage Currents of Zinc Oxide Surge Arresters in 22 kV Distribution System Using Thermal Image Camera

Zinc Oxide (ZnO) surge arresters (SAs) experience thermal runaway when the temperature exceeds the acceptable limit. This phenomenon is associated with the increase in resistive leakage current due to degradation. This paper presents the electrical performance of ZnO SAs in 22 kV distribution systems using thermal image camera under the power frequency AC operating voltages. When ZnO surge arresters are installation takes a long time in distribution system over more than 5 years. For the experimental study, as ZnO installation takes a long time over 6 years the leakage current is 63.9 mA, temperature differences were measured over a period of time over 14 degree Celsius. This data will be useful as a guideline for solving problems and reducing power loss from leakage current. Moreover, it will be useful in predicting lifetime of ZnO SAs.

Study of the Electric Filed Around a Metal Oxide Surge Arrester： Measurement and Simulation

The study of the electric field around a surge arrester is useful for design procedures and diagnostic tests. The current work com- putes the electric field around a medium voltage gapless surge arrester using 2D and 3D representation of the arrester. The 2D simulation design, which is described in IEC 60099-4 Standard, cannot include the non symmetrical parts of the arrester geometry and the test arrange- ment. 3D simulation procedures have the advantage that takes into account these asymmetries, giving more accurate results for each measurement position. In order to confirm the suitability of the created models, the simulation results of the electric field, using the 2D and 3D edition of PC Opera, are compared with recorded measurements, which are obtained in laboratory using appropriate calibrated field meters.

基于层次分析-熵权法的氧化锌避雷器阻性电流测试仪综合质量评价

为科学、有效地评价氧化锌避雷器阻性电流测试仪产品的质量水平,辨别优劣供应商,提出了一种基于层次分析-熵权法的测试仪综合质量评价方法。通过数理统计分析、试验结果量化赋值和加权调整等方法,从技术性与经济性两个维度提取出质量评价指标,经过主客观组合赋权,结合客观数据得到产品的综合评价指数,实现对不同厂家产品的综合质量排序。算例分析结果表明,该方法能够较好地区分不同厂家测试仪的质量水平,凸显部分产品存在的测量结果分散性大、抗干扰性能差、维修经济性差等质量短板或薄弱环节,可为相关产品质量提升、招标采购和入网检测提供参考。

架空输电线路氧化锌避雷器实时监测系统设计

为实时监测氧化锌避雷器的状态和性能,文章设计一套架空输电线路氧化锌避雷器实时监测系统。该系统使用低能耗的远距离无线电技术,并通过远程监控平台进行数据传输和分析,实现对氧化锌避雷器的实时监测和故障诊断。该系统具有良好的实时性和准确性,能够有效提高架空输电线路的安全性和可靠性。

基于检测结果的27.5kV交流无间隙金属氧化物避雷器质量提升措施

针对近几年委托检测的电气化铁道供电用27.5 kV交流无间隙金属氧化物避雷器检测结果,统计检测结果为不合格的试验项目。分析密封试验、弯曲负荷试验、2 ms方波电流冲击耐受试验、电阻片4/10大电流冲击耐受试验等试验项目检测结果为不合格的原因,提出27.5kV避雷器质量提升措施。

Oxidation Kinetics of Aluminum Powders in a Gas Fluidized Bed Reactor in the Potential Application of Surge Arresting Materials

In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general.

埃及轻轨牵引供电系统避雷器选型与配置探讨

介绍避雷器在电气化铁道牵引供电系统中的应用,根据IEC标准给出避雷器的额定电压、持续运行电压、标称放电电流关键参数的计算原则,结合埃及轻轨牵引供电系统分析了220 kV、27.5 kV、20 kV避雷器的参数选型计算,总结梳理埃及轻轨牵引供电系统的避雷器配置,针对项目避雷器运维难点给出解决措施,实现了兼具“一带一路”国家本土特点和中国特色的中国智慧、中国方案、中国装备走出去的良好示范。

避雷器放电计数器校验仪校准方法的研究探讨

基于对避雷器放电计数器校验仪工作原理、功能和计量特性的分析,提出了一种针对避雷器放电计数器校验仪的校准方法。本文通过采用直接测量法测量雷击动作计数功能的相关参数,采用标准源法测量“毫安表校验”功能的相关参数,试验结果表明雷击动作计数功能的主要技术指标是不小于100A、8/20μs的冲击电流信号,“毫安表校验”的量程(有效值)为工频电流30mA,试验验证了校准方法的可行性和适用性,为避雷器放电计数器校验仪的校准提供一种新的技术途径以及制定规程规范的参考依据。

粘接工艺对10 kV避雷器整体大电流的影响分析

10 kV避雷器是低压配网中一种重要的过电压保护装置,大电流冲击耐受能力是避雷器整体性能的重要指标.对于10 kV避雷器,现在大多数厂家采用的是杜力顿芯体,封装前电阻片芯组采用PA胶带固定,这对10 kV避雷器整体大电流冲击耐受能力影响较大.为了提高避雷器的大电流冲击耐受能力,通过改进生产工艺,封装前电阻片芯组采用粘接工艺固定.试验结果表明,电阻片的特性与避雷器的特性不能完全等价,粘接工艺对于提高避雷器的整体大电流耐受能力有着巨大作用.

金属氧化物避雷器检测方法的现状与发展

为保证金属氧化物避雷器 (MOA)的安全运行 ,必须对避雷器进行预防试验、带电检测或在线监测。在综述避雷器的检测方法后 ,指出了每种检测方法的优点及实际应用中存在的问题 ,介绍了国外避雷器在线监测最新动态。

电力系统故障限流器研究综述

总结了电力系统故障限流器(fault current limiter,FCL)的研究和发展现状,介绍了FCL的主要分类、特点以及不同限流方式的经济型FCL实现方案,归纳了FCL实用化研究中需要解决的关键问题,包括:FCL与电力系统整体性能的交互影响;FCL与电网中发电机、变压器、断路器、继电保护装置等关键设备的交互影响;FCL的经济性评价;FCL的优化设计;FCL在线状态监测等。文章还简要介绍了作者针对ZnO避雷器式故障限流器提出的新型实用化设计方案及其应用研究的进展情况。

500 kV线路ZnO避雷器电位分布计算与试验分析

采用一种新的模拟面电荷—表面电荷法对研制的两种５００ｋＶ悬挂式ＺｎＯ避雷器阀片柱沿面电位分布进行了计算。计算与现场实测结果进行对比，验证了计算结果的正确性。

一起氧化锌避雷器故障原因分析与思考

对一起110 kV氧化锌避雷器故障进行了分析。对避雷器进行外观检查、解体分析,对电阻片测量绝缘釉厚度以及10 k A冲击电流试验,对电阻片柱电位分布开展有限元仿真分析和实际测量,发现故障是由于该结构避雷器底部金属支撑杆较长,吸潮硅胶绑缚位置较高,吸附装配中残余潮气后对瓷套放电引起。针对此次故障提出了加强避雷器结构设计选型、加强避雷器工艺管控和加强在役设备巡检等3点改进措施,以提高避雷器的运行可靠性。

葛洲坝换流站金属转换开关操作引起的避雷器事故分析及对策

在 1998年葛南直流输电工程额定容量考核试验中 ,葛洲坝换流站 1台MRTB并联避雷器在金属转换开关操作时发生故障损坏。笔者通过试验研究和EMTP计算 ,得出了MRTB并联避雷器损坏的主要原因是该型避雷器密封不严 ,水分潮气进入所致。建议将新购的 16台避雷器全部安装 。

高速铁路牵引供电接触网雷电防护

中国高速铁路多采用高架桥敷设方式,牵引供电接触网的导线对地高度较大,雷击跳闸率较高,必须采取有效措施加以解决。建立了接触网的雷电过电压计算模型,并基于矢量匹配技术和网络综合理论提取了高架桥冲击阻抗的等值电路;计算分析了接触网雷击跳闸的概率和特点。结果表明:接触网F线的雷击跳闸率很高,而受到F线屏蔽的T线雷击跳闸率较低;提出了将PW线兼做避雷线使用以及在F线绝缘子上安装带串联间隙避雷器的防护方案,同时,建议加强高架桥非预应力结构钢筋与接地钢筋的可靠等电位连接,以提高防护方案的效果。

线路避雷器提高超高压大跨越架空线路绕击耐雷水平的仿真研究

为研究加装线路避雷器对提高超高压大跨越段绕击耐雷水平的有效性，参照官亭一兰州东750kV输电线路实际参数，建立了雷电流、输电线路、杆塔、绝缘子串和线路避雷器的EMTP-RV仿真模型，分析了不同雷击位置、不同避雷器装设方案、不同杆塔接地电阻对耐雷水平的影响。仿真结果表明：在跨越段两端各加装1组线路避雷器可将线路整体绕击耐雷水平提高至81～119kA，远远超过理论最大绕击雷电流30kA，并克服了接地电阻的影响，其中本基塔绝缘子被完全保护，但附近杆塔上绝缘子获得的保护作用有所弱化，若要实现完全保护，则需在跨越段两端及其相邻杆塔上都加装线路避雷器。

在线监测氧化锌避雷器的容性电流补偿法

对容性电流补偿法测量氧化锌避雷器泄漏电流的原理及在线监测方法的实现进行了介绍 ,说明了电网谐波对氧化锌避雷器在线监测的影响。证明了泄漏电流容性三次谐波分量与流过置于避雷器法兰附近的电场探头电流的三次谐波分量的确定关系。提出了测量泄漏电流中阻性电流分量的公式 。

加装金属减震装置的1000kV避雷器振动台试验研究

为研究用于电气设备金属减震器的力学性能和减震效果,进行了单个减震装置的拉压循环加载试验和加装减震装置的1 000 kV避雷器振动台试验。试验结果显示金属减震装置的本构关系符合Wen模型,表现出良好的耗能特性。在地震台试验中,减震装置的应用使设备基频从1.61 Hz降低至1.22 Hz,阻尼比由1.73%增大至4%,改善了设备的动力特性。在0.4×9.8 m/s2等级地震荷载下设备应力为22.6 MPa,安全系数为2.0,减震装置对应力的减震率达60%,显著提高了设备的地震安全性。金属减震装置通过金属芯体的塑性变形耗散地震动能量,减小地震响应从而提高了设备的抗震性能,为1 000 kV电气设备应用于我国高抗震设防烈度区提供了技术支撑。