确定避雷针保护范围的新方法探讨

分析现有确定避雷针保护范围方法的缺陷 ,提出将引雷角 4 5°、考虑滚球半径影响的避雷针保护范围设计为标准保护范围 ,用于确定不同架设高度的避雷针保护范围的新方法。     

双支等高避雷针保护范围计算

阐述了避雷针保护范围的设计原则,基于滚球法确定避雷针保护范围的方法,推导了双支等高避雷针在h_x高度x-x平面的保护范围计算公式,实际应用证明了该计算公式在避雷针设计计算中的方便性。     

多支避雷针保护范围的安全漏洞及其堵漏措施

针对现行折线法确定多支避雷针保护范围的安全漏洞问题,提出了确定多支避雷针保护范围的新方法。该法确定的多支避雷针间保护范围受45°保护角、滚球半径、针高及针间距离控制,可以克服现行折线法的缺陷,使设计更趋合理。     

高效避雷针保护范围的确定

本文根据ＦＤ１型高效避雷针的直流击穿电压和放电－几何模拟理论确定其保护范围，得到高效避雷针比普通避雷针多出１５米的截击距离。本文还对高效避雷针机理做了初步分析。     

避雷针保护范围不能“绝对化”

分析了避雷针的防雷保护原理和影响避雷针保护范围的主要因素。通过实例比较了避雷针防雷保护范围的计算方法,讨论了避雷针防雷保护范围的计算公式,认为影响避雷针防雷效应的主要因素无法定量,其保护范围只相对于被保护物在此空间内遭受雷击的概率而言。避雷针保护范围不能“绝对化”。     

论避雷针群的优化配置及安全裕度

依据规程给定的避雷针防雷保护数学模型，提出了最大保护距离的概念，将求空中最小保护宽度问题转化求地面上相邻避雷针间极限距离的问题。从而，可准确地确定安全裕度和所需避雷针的支数，并得出等高避雷针是首选方案。     

避雷针保护的直接作图法及其校验

对传统的避雷针保护范围的计算和作图方法, 做了进一步地研究探讨, 结论是在布置避雷针位置时, 只要控制两针间的距离不超过允许距离的最大值, 就可以直接画出保护范围图。从而将原本烦琐的避雷针保护范围计算方法, 简化到一般情况下, 可以不做计算。     

滚球法确定接闪器保护范围的几何分析

从立体几何和平面几何原理角度,对利用滚球法确定单支、双支避雷针保护范围进行了说明与分析。介绍了常州新一代天气雷达站接闪器的设计过程。经分析、计算,确定安装3支15.8m等高避雷针和1.5m高不锈钢护栏作为混合接闪器,以保证天气雷达站安全、有效。     

基于MATLAB的避雷针保护范围的计算机辅助分析

利用MATLAB设计出对避雷针的防雷安全范围进行图像化显示和计算机辅助分析的应用软件，使用方法简洁，显示效果直观明了，为避雷针防雷范围的确定和避雷针设置的计算机辅助分析设计提供了一种简便的方法。     

别把避雷针(线)保护范围"绝对化"

分析了避雷针(线)的防雷保护原理和影响避雷针(线)保护范围的主要因素,认为：1)当今国内外所有避雷针(线)防雷保护范围的计算公式都是经验公式,这是因为影响着避雷针(线)防雷效应的主要因素无法定量;2)所谓避雷针(线)保护范围是相对于被保护物在此空间内遭受雷击的概率而言的,各种文献规定的保护范围不同,是因允许遭受雷击概率不同;3)不能把避雷针(线)保护范围“绝对化”。     

应用线路避雷器提高交流输电线路耐雷水平

线路避雷器在雷电活动强烈、降低杆塔接地电阻困难的特殊线段上使用 ,可有效提高输电线路的耐雷水平。耐雷水平的提高与线路避雷器的安装方式和安装组数有关 ,且应尽量降低杆塔的冲击接地电阻。线路避雷器仅能保护安装了线路避雷器的杆塔自身的线路绝缘子 (串 )不发生雷击闪络 ,无外延的雷击保护范围。     

浅议220 kV韶郭线安装氧化锌避雷器后的运行效果

韶关电厂至郭塘变电站的２２０ｋＶ输变电线路大部分杆塔地处粤北山区,雷电活动强烈,常发生雷击跳闸故障。为此,选择在韶郭线雷电易击段安装氧化锌避雷器的方法,来提高线路的防雷性能。通过雷电定位系统的分析比较,安装氧化锌避雷器后,线路跳闸次数明显下降,事实证明这种方法的防雷效果较好。     

采用避雷器防止10kV架空绝缘导线雷击断线

在绝缘导线应用于配电线路的建设中,10 kV架空线路雷击断线事故是影响安全供电的大问题.通过分析架空绝缘导线雷击断线的机理,介绍安装线路型金属氧化物避雷器可有效限制雷电过电压对配电线路的危害,减少绝缘导线配电线路的雷击断线事故,保证配电线路的安全运行,指出安装线路型避雷器这一防雷技术存在的问题,并分析了线路型避雷器的安装密度和保护效果.     

Lightning protection of overhead power distribution lines

There are two major protective methods against lightning outages on overhead distribution lines. One is by use of surge arresters and the other is by an overhead ground wire. Surge arresters have rather constant effect regardless of the type of lightning outage causes. On the other hand, the effect of an overhead ground wire is quite different against the two major causes: direct lightning hit and induced overvoltages. This paper shows how to design lightning protection for overhead power distribution lines taking these characteristics into account. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Suppression of lightning-induced overvoltages by distribution line surge arresters

The primary aim of surge arresters in power distribution lines is to protect lines and equipment from the voltage induced by nearby lightning strokes. To further improve power systems, methods to protect distribution lines against direct lightning strokes are still needed. An effective measure against direct lightning strokes is to increase the number of arresters. However, if the surge current is too large, some surge arresters absorb energy in excess of their capability and may break; this leads to a line fault. To evaluate the protective effect of the surge arresters against direct lightning strokes to overhead ground wire, the authors measured both the voltage across the surge arresters and the energy absorbed by them using a full-scale model line and a 12 MV impulse generator. The results were compared with simulation results by EMTP. There have been no previous studies making a comparison of this kind.     

110～500 kV输电线路的绕击雷害分析

文章以避雷线、导线的雷电击距及引雷角相等,分析了110～500 kV输电线路绕击雷害,并提出了确定110～500kV输电线路避雷线的引雷范围、保护范围、绕击范围的方法。分析计算结果表明:110～500kV输电线路的绕击雷害与线路附近及档距中央导线下方的凸出地形、树木、建筑物,以及避雷线对导线的保护角、避雷线与导线之间的垂直距离等有关。     

Mechanism of pole‐mounted transformer damage by backflow lightning and measures against the damage on low‐voltage distribution line

Pole‐mounted transformers are especially vulnerable to lightning damage. The progress of the information society imposes increasingly stringent requirements for the reliability of electric power supply, and this in turn necessitates a reduction in lightning damage to pole‐mounted transformers. Lightning protective devices (surge arresters) are now being installed around the primary bushing of the transformers, which has decreased the number of disconnections around the primary bushing due to lightning. But surge arresters installed on the primary side of the transformer cannot protect it against backflow lightning entering the secondary side of the transformer. The characteristic of transformer damage by backflow lightning is that the electromagnetic force produced by the current flowing into the secondary side deforms the transformer windings. This paper elucidates the mechanism of transformer damage by lightning flowing into the secondary side by comparing actual lightning damage cases with the results of verification tests using a short‐circuit generator. Effective countermeasures against transformer damage by backflow lightning are examined by EMTP calculations, which indicate that neutral grounding on the low‐voltage distribution line is the most effective way of decreasing the current flowing into the transformer. The lower the grounding resistance, the less current flows into the transformer. In addition, decreasing the voltage on the secondary side is important in order to protect the secondary‐side bushing. The calculation results indicate that surge arresters installed around the secondary side of the transformer are effective in decreasing the voltage on the secondary side. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(2): 1–11, 2010; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20921     

建筑物防雷设计中几个问题的探讨

通过三个问题以及针对每个问题的两种不同答案,对避雷针的离地高度进行了论述.运用作图法阐明了防雷带的作用,指出装了避雷针就可以不装防雷带的观点是错误的.最后通过避雷针保护范围的计算,说明了在重要工程中采用提前放电式避雷针的重要意义.     

Distribution arrester outages caused by lightning backflow current flowing from customer's facility into power distribution lines

Direct lightning strokes are considered to be a main cause of damage to surge arresters on power distribution lines. Recently, lightning performance of distribution lines has been observed using still cameras, and lightning‐caused distribution outages on hilltop areas on the coast of the Sea of Japan have been investigated. This research has shown a possibility that lightning backflow current flowing from customer facilities into distribution lines causes damage to surge arresters on the distribution lines. We have investigated the lightning backflow current flowing from customer facilities into distribution lines as a cause of damage to surge arresters. The main results are as follows: (1) The electric charge of the backflow current flowing into distribution lines is more than 60% of that of the lightning stroke current. (2) If the grounding resistance of the customer's facility is not low, the failure rates of a surge arrester caused by backflow current due to winter lightning is more than 90% of that caused by direct lightning strokes. © 1999 Scripta Technica, Electr Eng Jpn, 126(3): 9–20, 1999     

Investigation of effect of transmission line arresters verified by lightning surges at substations

In recent years, transmission line arresters have been installed to protect overhead power transmission lines from backflashovers caused by lightning. In addition, it has been expected that substation lightning surges incoming via transmission lines can be suppressed by them. However, the suppression effect by those with series gaps has not been investigated sufficiently. The author has measured lightning surges at two 77‐kV substations from 1990 to 1993. As the transmission line arresters have been mounted on the towers since 1992, the lightning surges due to the sparkover of the series gap of the transmission line arresters can be observed at the substations. In this paper, the lightning surge waveforms due to such sparkover have been analyzed in detail. Next, an accurate EMTP simulation method considering the induced lightning surge voltages has been proposed. Finally, their suppression effect has been investigated by simulation corresponding to each mounting method. © 1999 Scripta Technica, Electr Eng Jpn, 126(4): 30–39, 1999