Limitations of Lightning Rods in Preventing Direct Lightning Strikes

Since ancient times,lightning disasters have undoubtedly been an unstoppable threat to humanity.During thunderstorms,lightning often damages objects on the ground,such as buildings and structures.Since Franklin invented the lightning rod in 1752,lightning rods have been used worldwide to prevent direct lightning strikes in various fields such as high-voltage power transmission lines,outdoor chemical sites,highways,land and sea wind farms,and forest lightning fire protection.It has been proven that lightning accidents still occur frequently in places where lightning rods are installed and the protective angle method is used.In order to further study the protective effect of lightning rods and identify the shortcomings of lightning rod protection,negative lightning strikes are taken as the research object,to analyze the limitations of lightning rods in preventing direct lightning strikes from the working principle of lightning rods.

Three Core Technical Systems and Engineering Application of Regional Lightning Protection

Regional lightning protection is a complete theoretical system,mainly including:lightning interception technology(LIPT),lightning strong electromagnetic pulse high-energy absorption technology(MSPD),and regional lightning activity law analysis technology(RLLA).Lightning interception technology uses dispersive waveguide resonant cavity technology to achieve the functions of 46.55 m longer than upward leader of ordinary lightning rod,significantly reducing lightning strike point current by 40%,optimizing space electromagnetic field environment,and effectively intercepting overhead and side lightning strikes,and overcome the limitations of traditional lightning rod.The lightning strong electromagnetic pulse high-energy absorption technology uses distributed parameter balance technology,special disconnector for short circuit current,and parity pairing technology to achieve stronger surge absorption capacity than traditional single pulse SPD and international advanced technical indicators such as timely breaking under power frequency short circuit current,and good energy and time coordination.The analysis technology of regional lightning activity laws accurately identifies lightning strike points through comprehensive analysis of regional lightning activity laws,physical parameters of ion clouds,and the impact on ground electric fields.The three core technology systems complement each other,achieving all-round protection against direct lightning strike and lightning electromagnetic pulse.Several projects achieved zero lightning damage,effectively ensuring the safety of buildings and electronic and electrical equipment in the protected area.

Consolidated Lightning Protection Methods of Landfill and Incineration Plants and Its Application Technology Investigation

Taking lightning-protection engineering of Wuhan Changshankou landfill and incineration plants for the example,in this article,we have discussed the integrated technology of direct lightning protection by early streamer emission lightning rod,lifting lightning rod and mobile lightning rod. Additionally,lightning protection methods and measures of landfill with large receiving area of lightning strike and landfill gas and incineration plant with irregular landfill cell are explored.

Identification of Lightning Stroke and Fault in the Travelling Wave Protection

To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of symmetric current wave-form induced by lightning stroke without causing fault and that of asymmetric current waveform generated by fault within a very short time interval, the waveform of transient current above and below time-axes are integrated respec-tively. First, through comparing the relative ratio of them with threshold value, the primary criterion identifying fault and lightning stroke is constructed;Secondly, to improve the reliability of discrimination between lightning stroke with and without causing fault, according to the difference of them, the secondary criterion is also defined. The simulation results and analysis demonstrate that the proposed integral criterions are valid and correct.

Analysis on Lightning Strike Cause of Directly Buried Optical Cable in Wind Farm and Its Prevention Methods

Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected by lightning, sometimes lightning damaging optical cable and flashover discharge accidents of optical cable port occurred. In this paper, the amplitude spectrum of lightning wave, the breakdown depth and breakdown distance of lightning wave to soil, the metal components of optical cable port and the impedance characteristics of grounding wire are systematically analyzed, and the prevention methods of directly buried optical cable in wind farm to avoid lightning damage are proposed.

Study on the Lightning-Protection of Ancient Buildings

By reviewing ancient buildings that were destroyed by lightning strike or fire caused by lightning,lightning protection of ancient buildings was discussed,ancient architectural complex in Dagu Mountain,a provincial-level scenic area of Liaoning,was taken for an example to detect potential safety hazards in lightning-protection of those ancient buildings,5 types of potential safety hazards were summarized.By studying the classification of ancient buildings' lightning-protection,protection level,lightning-protection measures,design basis of lightning-protection engineering,construction and new construction technology,relevant technical specifications were taken as references for proposing 4 countermeasures against those potential safety hazards from the perspectives of exterior and interior parts of ancient buildings,lightning-protection of ancient trees and so on.In view of actual conditions of the ancient architectural complex in Dagu Mountain,construction plan,personnel placement,labor planning,construction quality control system,acceptance of works,technical documentation and such matters were specifically discussed to give useful support to the future lightning-protection of ancient buildings.

Protective Measures to Oil Depot Against Lightning Stroke and Electrostatic Spark

Introduction Lightning can cause great destruction. According to the record in the northern China, more than 150 lightning strokes occur on a power system annually. High voltage (millions of volts) and large current (hundreds of -kA) associated with lightning, will damage property and even kill people and livestocks. It will be very dangerous if a lightning stroke strikes oil depot of power plant or substation. In addition, the high voltage induced by the electrostatic charge generated due to oil flowing will probably cause damage unless the electrification has been limited and drained off.

Contribution to the Study and Analysis of the Lightning Aggression on the Wind Turbine

Generally, lightning damage has mainly been to home appliances and telephones, towers and power transmission and generation equipment mal functions and damage due to strikes on power lines. With the adoption of wind power generation equipment, however, lightning damage is also increasing in this area. Through his dimensional characteristics, the wind power system is more exposed in the nature compared to all others systems. Lightning damage is the single largest cause of unplanned downtime in wind turbines, and that downtime is responsible for the loss of countless megawatts of power generation. The wind turbines are important structures, since they can easily attract the wrath of storms hits heights close, they can also capture the most distant. The rotation of the blades may also trigger lightning and result in considerable increase in the number of strikes to a wind turbine unit. Since wind turbines are tall structures, the lightning currents that are injected by return strokes into the turbines will be affected by reflections at the top, at the bottom, and at the junction of the blades with the static base of the turbine. We present our contribution in this paper to study lightning strokes and their effects on the wind turbines with the aim to enrich the work and to suggest more effective means of protection against lightning.

考虑暂态过电压特性的架空输电线路雷击故障时空预警方法

针对运行环境复杂多变,故障率持续居高不下,雷击故障占比较大,并具有随机性与无法预知性的问题,提出考虑暂态过电压特性的架空输电线路雷击故障时空预警方法。深入解析雷击机理与雷电流,确定雷击(感应雷与直击雷)输电线路暂态过电压计算方式,通过小波多分辨率分解算法处理输电线路暂态信号,评估暂态过电压在信号频段中的能量比,识别累计故障,判断雷击点与故障点是否一致,利用单端检测确定雷击点的位置,完成架空输电线路雷击故障的时空预警。实验数据显示,在不同实验组别背景下,当阈值pΔ取值为9.3时,雷击故障识别精度达到最大值92%,雷击点定位精度高达80%。可以获得精准的雷击故障识别结果与雷击点定位结果,充分证实了提出方法具备较好的雷击故障时空预警效果。

基于先导发展模型的船舶直击雷防护分析方法

大型船舶平台搭载的精密仪器和探测装置相对其他设备高度较高,有尖端突起且抗干扰性较差,是海面上明显的突出物,雷电防护成为现代船舶重要的研究内容。本文提出一种基于海洋复杂环境改进Wiesmann-Zeller(WZ)模型概率发展函数的船舶雷电防护分析方法,建立了海面雷电先导发展模型,以大型远洋调查船为对象,研究其雷击点的概率分布,并结合船舶特点进行了多避雷针的分析计算。基于本文提出的模型,通过Matlab软件模拟雷击船舶过程,揭示了防护范围、效果与避雷针位置、数量高度之间的关系,对比分析了不同避雷针数量和避雷针高度下的雷击概率和防护效果,验证了三针不等高为最优方案,能够指导和完善实际工程实践,保证船舶雷电防护效果的充分发挥。

三星堆博物馆新馆智能防雷监测系统设计与实践

针对三星堆博物馆新馆建筑特点和所处环境,设置智能防雷监测系统,利用信息化手段,对博物馆周边气候环境、新馆外部防雷装置、电涌保护器等防雷设施进行实时在线监测,并通过技术手段实现雷电预警和实时推送,有效提升了博物馆的雷电防护水平。

电气化铁路柱上开关站的防雷现状及改进措施

雷电对柱上开关站这种新型的电气化铁路牵引供电设施的运行安全存在一定威胁,目前尚未有文献研究其防雷措施。直击雷在落到柱上开关站一次设备上时产生的高电压可以被进出线侧和接触网上网点的避雷器吸收。雷击中柱上开关站的接地部分会产生巨大雷电流,通过容性耦合、感性耦合和地电位反击等方式威胁二次综合自动化设备的安全。双层屏蔽铁箱可有效降低雷电流对二次设备的威胁,因此,柱上开关站既有的防雷措施基本有效。若工程预算充足,可采取加装避雷线和在二次控制端子中额外增设SPD的方法来进一步增强柱上开关站的防雷能力。

基于等效离子防雷技术的移动通信基站雷电防御方法

传统的防雷方法主要采用避雷针、地网等手段来引导雷电流入大地,然而这种方法在应对电磁脉冲的干扰方面较为薄弱,导致防雷效果并不好。为此提出基于等效离子防雷技术的移动通信基站雷电防御方法。首先,确定等效离子阻雷的安装位置,以便很好地覆盖基站区域;其次,设置大气电场雷电阈值,实时监测雷电活动;第三,实施雷电距离警报,及时发出预警信息;最后,利用等效离子防雷技术改变雷电自然路径,降低雷电对基站的潜在威胁。实验结果表明:与避雷针和接地防雷技术相比,基于等效离子防雷技术的移动通信基站雷电防御方法能有效吸收和中和电磁脉冲,降低雷电对电子设备的干扰和损坏,防雷效果更好,具有实际应用价值。

雷电危害机理及ZPW-2000A轨道电路防雷措施研究

详细阐述不同雷电类型,例如直接雷、静电感应雷、电磁感应雷的危害机理。结合现场调查情况和实验室的测试情况,分析侵入ZPW-2000A轨道电路的途径,综合分析危害机理及侵入途径后,制定相应的横向、纵向防雷措施,并对“泄”“抗”“悬浮”等防雷特点进行阐述。

天线直击雷防护一体式设计

为提高机动装备的直击雷防护能力,探究天线与一种非引雷原理的直击雷防护装备一体化设计理念。通过天线和直击雷防护设备的适当选型并进行一体化结构模拟设计,分析二者一体化设计前后天线信号传输工作状态和异常接闪时对天线信号传输的影响,通过对比前后天线传输的数据变化来探讨二者共存的可能性;并通过对天线传输特性仿真分析及模拟雷击试验结果来验证该二合一产品设计的电气性能满足天线传输要求。该设计理念在保证天线通信正常的前提下可同时增强天线设备的直击雷防护能力,为后期机动通信装备的直击雷防护提供一种新的解决方案。二者的结构强度保证特别是在有抗风要求的条件时,还需在实际设计及应用过程中进行进一步的可行性论证及试验验证。

淳安农村供水站防雷安全技术探讨

该文主要着眼于淳安农村供水站系统的特点及工作原理,分析直击雷、雷击电感脉冲、雷电波入侵及地电位反击方面对农村供水站运行产生的危害及损失。该文分别从供排水系统、自动化仪表系统、供配电系统及终端设备方面,提出较为系统的农村供水站雷电防护的应对措施,以供大家参考。

基于自动化监测的气象站观测场防雷技术研究

针对当前气象站观测场防雷技术采用统一的防雷方案,忽视了气象站观测场内各设备的差异性,导致设备雷击率较高的问题,设计一种基于自动化监测的气象站观测场防雷技术。首先构建气象站观测场雷电幅值自动化监测系统,获取气象站观测场雷电幅值以及过场电压。选择规程法计算设备的反击跳闸率,以此确定现有避雷设备耐雷性能。计算避雷设备保护范围,结合观测场雷电幅值,设定差异化综合防雷技术。实验结果表明:此技术可有效缩减观测场雷电幅值与波动,降低设备雷击率,进一步提升气象观测的安全性。

超高压输电线路防雷技术的研究

为全面优化超高压输电线路安全控制水平,要结合实际应用运行环境,落实规范化防雷技术手段,搭建完整且可控的技术管理模式,维持超高压输电线路安全作业,更好地避免雷电造成的安全隐患。文章简要分析了超高压输电线路防雷技术应用的重点,并对具体的技术措施展开讨论。

某广播电视发射站的防雷策略优化

广播电视发射站是我国进行电视、广播信号接收的重要设施。在实践中,出于接收、发送无线广播信号的需要,此类建筑通常修建在当地海拔最高的位置。发射站自身包含大量电子设备,很容易受到雷电侵扰。对发射站防雷技术及其应用进行研究具有一定现实意义。通过查阅相关文献,研究广播电视发射站基本理论,结合实际工作案例,分析广播电视发射站防雷技术应用及其存在的问题,在此基础上,提出针对广播电视发射站防雷技术的优化策略。

炼油化工企业现场自动化仪器仪表设备防雷技术初探

随着我国炼油化工企业的飞速发展,行业自动化仪器仪表的使用越来越广泛,自动化仪表设备的检测精度及稳定性极易受到外界电磁干扰,尤其是雷电频发区域,雷电影响很容易使仪表发生损坏.结合工程实例,对炼油化工企业现场仪表受雷击形式以及防雷技术措施进行探讨.