220kV变电所避雷器设置

要有效限制变电站侵入波过电压,须安装并正确设置避雷器。介绍了220kV及以下电气设备的绝缘配合原则,分析了雷电过电压的特征;根据上海采用气体绝缘金属封闭开关设备(GIS)的220kV变电所的避雷器设置现状,对照相关的规程规定,对上海的此类变电所避雷器位置的正确设置进行了探讨。     

500kV锦西沙河营变电所防雷保护及设备绝缘选择

针对５００ｋＶ锦西沙河营变电所近期投建规模、５００ｋＶ母线加装避雷器前后的几种运行方式,利用计算机对该变电所５００ｋＶ线路雷电侵入波进行模拟过电压计算,估算出变电所内５００ｋＶ各种设备的最大雷电冲击过电压值,从而为该变电所的设备绝缘选择、避雷器绝缘配合及母线是否配置避雷器提供了设计依据。     

GIS绝缘水平的研究与EMTP

<正> 一、引言 变电所防止雷电与操作过电压中,GIS的保护性能在许多重要方面与敞开式的变电站不同。传统变电站的绝缘水平主要取决于变压器的保护物——避雷器的正确选择及它们的安装位置;它的空气绝缘的强度可以自动恢复,开关可以耐受如绝缘子或套管闪络这样的故障。而GIS的绝缘不具有自动恢复的这个特性,在遭受过电压时,故整个GIS系统(母线,断路器,隔离开关和接地开关等)必须得到全面的保护。另外,架空线的进线段到GIS开关之间的母线也同样需要保护。GIS装置中,避雷器不必要紧挨着变压     

GIS中快速暂态过电压的仿真计算

采用 EMTP程序仿真计算了天荒坪抽水蓄能电站5 0 0 k V GIS系统隔离开关操作产生的快速暂态过电压。分析了影响过电压幅值的因素、系统避雷器的计数器频繁动作的原因与快速暂态过电压对变压器绝缘的危害     

特高压GIS变电站雷电侵入波过电压分析

针对特高压GIS变电站内雷电侵入波过电压问题,采用ATP-EMTP电磁暂态仿真程序,建立1 000kV GIS变电站的雷电过电压计算模型,通过对变电站内设备上最大过电压计算分析,验证变电站设备的绝缘裕度,进而确定并优化1 000kV GIS变电站避雷器的布置方案。     

420kV GIS变电站雷电侵入波过电压计算与防雷措施研究

420kV GIS变电站在发生雷电侵入过电压时,雷电波将沿线路传入变电站,严重影响设备的绝缘水平,其与保护装置避雷器之间的绝缘配合问题是电力系统中最基本和最重要的一种绝缘配合。对氧化锌避雷器的工作原理、特性及雷电流的模拟进行了阐述,以某420kV GIS变电站为对象,利用电磁暂态程序(ATP-EMTP)搭建了电磁暂态仿真平台,对国外某420kV GIS变电站400kV侧出线段杆塔受雷击时,引起绝缘子发生闪络后侵入波雷电过电压进行计算,在其最严重的单线单母单变运行方式下,在给定避雷器配置方案措施下,获得420kV GIS变电站出线端电压互感器及主变压器端口的过电压波形。通过计算分析,设计满足规范及工程实际要求。     

500kV GIS升压站主变合闸过电压影响因素分析

气体绝缘组合开关(GIS)在操作过程中会形成快速暂态过电压,影响与之相连的一次设备尤其是变压器的安全运行。为对GIS升压站主变合闸过电压进行量化,采用电磁暂态分析软件ATP-EMTP建立分布参数模型,对GIS升压站设备投运情况、出线数量、变压器与GIS母线连接管道的长度、避雷器与高压绕组距离对主变合闸过电压的影响进行仿真计算,得出了主变合闸过电压的特点。分析认为GIS操作时波的折反射是导致合闸过电压升高的主要原因,对于结构复杂的GIS升压站应开展过电压评估。     

关于修订330kV 电网过电压保护与绝缘配合标准的建议

本文提出以金属氧化物避雷器作为限制330kV 电网操作过电压的主要措施;对架空送电线路、变电所及其电气设备的绝缘配合方法和关键技术参数提出了一些修订建议.     

泉城110kV变电站雷电过电压保护方式的研究

<正> 1 前言 本文主要针对泉城110kVSF_6全封闭气体绝缘变电站(G IS)的过电压保护方式,从技术可行性和经济性角度进行了比较研究。该变电站过电压保护方式,在原初设时为进线电缆的送电端和受电端分别装设一级氧化锌避雷器,在GIS内两段母线上再分别装设一组氧化锌避雷器。现利用EMTP(ATP)电磁暂态计算程序,计算分析了该系统在各种过电压保护配置方式下雷电进波的特性,并考虑了GIS内隔离开关操作可能会     

±800kV直流系统过电压保护和绝缘配合研究

依托向家坝至南汇直流输电工程,研究了±800kV换流站交流侧工频过电压、交直流侧操作过电压和雷电过电压、直流线路操作和雷电过电压。重点分析了±800kV与±500kV在直流过电压和绝缘配合方面不同之处。给出了避雷器配置方式、参数的选择原则和方法,确定了换流站各避雷器的保护水平和配合电流及避雷器的能耗及能耗与直流侧的快速保护定值、延迟时间的配合。提出换流站绝缘配合裕度系数和主要设备绝缘水平要求及直流线路操作冲击和雷电冲击要求的最小空气间隙计算方法。     

Suppressing the effect of lightning-induced overvoltages by the combined use of surge arresters and overhead ground wires

Lightning voltage induced by nearby strokes is one of the causes of major overvoltages which threaten the insulation of power distribution lines. Surge arresters as well as an overhead ground wire usually are employed for the protection of equipment and line insulation on overhead power distribution lines. The fundamental mechanism of suppressing effects of overvoltages induced by nearby strokes has been demonstrated independently by one of the present authors for surge arresters and for an overhead ground wire. In this paper, the protective effect of the combination of surge arresters and overhead ground wire is analyzed. As a result, it is found that the effect of surge arresters used together with an overhead ground wire is almost the same as that of surge arresters alone.     

AN INVESTIGATION ON OPERATING CONDITIONS OF METAL-OXIDE ARRESTERS UNDER PT FERRORESONANCE

ABSTRACT

The operating conditions of metal-oxide arresters under PT ferro-resonance was investigated with EMTP in this paper. A simplified method was proposed to estimate the energy absorbed by metal-oxide arreater during ferroresonant overvoltages. Existence regions of the typical ferroresonance were derived from an ungrounded overhead system. A few types of metal-oxide arresters were introduced into the existence regions. Both the effect of metal-oxide arresters on the ferroresonant overvoltages and the arreater energy absorption were examined to discuss the actual behaviour of metal-oxide arresters operating under PT ferroresonance.     

Metal oxide arresters on distribution systems: fundamentalconsiderations

The authors compare the reliability of metal oxide and silicon carbide distribution arresters by examining the likelihood of failure as a result of moisture leakage and contamination, overvoltages, and lightning surges of high magnitude and long duration. It is found that metal oxide distribution arresters should be highly reliable in most applications because the arresters are far less likely than silicon carbide arresters to fail as a result of moisture ingress and contamination. Metal oxide arresters are more likely to fail as a result of system overvoltages because they conduct current in response to the overvoltages, and for this reason somewhat more care must be exercised in application to match the magnitude and time duration of system overvoltages to the temporary overvoltage capability of the arresters. Comparison of published metal oxide arrester energy absorbing capability against the energy absorbed in lightning surges that have been shown to exist indicates that the probability of failure may be high in areas of high lightning intensity. The authors suggest changes in the ANSI/IEEE C62.11 standard for metal oxide arresters to improve arrester reliability on lightning surges     

Insulation co-ordination for gas-insulated transmission lines (GIL)

In this paper focus is given to the insulation co-ordination of a closed system with integrated surge arresters. The calculations of transient overvoltages are made with typical applications of the integration of GIL in the 400 kV net of overhead lines. The overvoltages in the system are calculated and discussed for system lengths of 1 km and 10 km. Recommendations for such applications for the insulation levels are given. The GIL design configuration, the lightning overvoltages of overhead lines, and the overvoltages in the GIL are discussed under respect of overvoltage protection measures. Together with the use of surge arresters the insulation levels due to overvoltages are discussed. The insulation co-ordination is a very important measure for system optimization. Calculated values found for the insulation level of the GIL were proven with type tests and long duration test set-ups. Some test results are also explained in this paper     

Lightning overvoltage protection of the Paddock 362-145 kVgas-insulated substation

Backflashovers close to the Paddock 362-145 kV gas-insulated substation (GIS) have been analyzed with the electromagnetic transient program (EMPT) using a frequency-dependent multiconductor system. The severities of the lightning stroke currents were based on recent recordings in the eastern United States. The effects of corona attenuation and distortion were accounted for using a shunt linear model approach. Turn-up effects of both line insulator flashover voltages and surge arrester protective characteristics were based on manufacturer's volt-time curves. Wave-shaping effects of substation capacitances were modeling details in determining the overvoltages inside the GIS due to close backflashovers, which are caused by lightning strokes with varying intensity. These results are aimed at better evaluation of lighting protection requirements for GIS protected by metal-oxide surge arresters     

Effect of lightning overvoltages on low-voltage power distribution lines due to direct lightning hits to overhead ground wire

Overhead ground wires and surge arresters have been installed to protect high-voltage power distribution lines and apparatus from overvoltages induced by nearby lightning strokes. The effects of surge arresters for protection of high-voltage distribution lines against direct lightning strokes have already been investigated using the digital simulation program EMTP (Electromagnetic Transients Program). With regard to the protection of low-voltage distribution lines from overvoltages induced by lightning strokes, experimental analyses using a scale model line have been reported. This paper reports on the comparison between the experimental analyses and EMTP simulation of power distribution lines, including low-voltage lines, and the validity of EMTP simulation. Furthermore, this paper analyzes the overvoltages on low-voltage power distribution lines against direct lightning strokes to overhead ground wire using the digital simulation.     

外串间隙线路型避雷器在架空输电线路中的防雷作用

针对阳江地区输电线路存在遭受严重雷击跳闸的问题，分析了各种雷击过电压引起的线路闪络跳闸，介绍了外串间隙线路型避雷器在输电线路中间防雷的机理，指出在阳江电网中应用外串间隙线路型避雷器解决架空输电线路中间防雷的必要性及避雷器的安装选点原则，可供同行参考。     

500 kV惠汕线路采用复合绝缘外套避雷器的研究

通过广东省５００ｋＶ 惠汕线的工程实际情况,说明在线路上安装复合绝缘外套避雷器能有效地限制操作过电压,达到取消合闸电阻、安全经济运行的目的。并介绍了西安电瓷研究所和广东省电力试验研究所共同研制的５００ｋＶ 复合绝缘外套避雷器的特点。     

AC filter arrester application

Arresters are being used in increasing numbers to provide surge protection inside of harmonic filters. The continuous voltage across these arresters is frequently a mixture of significant magnitudes of various harmonic voltages. Temporary overvoltages may result from system overvoltages or filter overloading. This investigation considers both the continuous arrester heating caused by a mixture of harmonic voltages and the effect of temporary overvoltages in order to provide guidelines for the appropriate selection of an arrester voltage rating for this type of application     

Self-generated overvoltages due to open-phasing of ungrounded-wyedelta transformer banks

Disconnecting one phase of an ungrounded-wye delta transformer bank from the source can result in severe overvoltages due to neutral shift and ferroresonance. Neutral shift overvoltages are quantified and their impact on metal-oxide surge arresters are evaluated. Ferroresonance is shown by test data to occur when low-loss banks, 15 kV and higher, are open phased. Design and operating practices to eliminate or mitigate these self-generated overvoltages are discussed