500kV紧凑型输电线路绕击耐雷性能评估与分析

在考虑紧凑型线路杆塔结构、架空线弧垂和线路走廊地形地貌对输电线路绕击耐雷性能影响的基础上,通过仿真计算得到500 kV罗百Ⅱ线紧凑型输电线路事故段线路绕击率沿线路走向的变化情况.结合输电线路走廊微地形特点,对事故原因进行分析,并提出建议改造措施.对各种典型地形下500 kV紧凑型输电线路绕击耐雷性能进行比较,分析不同地形下输电线路绕击耐雷性能存在差异的原因.计算分析了避雷线保护角、杆塔呼高和地面倾角对500 kV紧凑型输电线路绕击防雷性能的影响.     

220kV输电线路防绕击侧针防护效果研究

雷击是高压及超高压输电线路的主要事故之一,反击跳闸发生的概率很低,绕击是发生故障跳闸的主要原因。可以在地线上架设水平侧向短针的分布式绕击防治措施以有效提高地线引雷能力,防止绕击跳闸。以西昌220 kV输电线路N148号杆塔为例,分析并比较了杆塔附近地线上安装防绕击侧针前后,线路绕击率、绕击跳闸率以及绕击雷电流幅值的变化情况。通过实例计算发现,防绕击侧针安装以后明显改善了线路的防绕击能力,可见安装防绕击侧针作为输电线路的防雷改造措施,具有较好的实用性。     

输电线路伸缩式防雷侧针的研制与应用

防雷侧针是近些年来安装在高压输电线路上的一种防雷设施,防雷侧针的安装能有效降低线路绕击率。目前多数电网建设中,安装在输电线路中的防雷侧针体积较大,不能够进行带电作业,只能利用停电时间进行安装。本文结合现场安装实际情况,开发出了一种新型伸缩式防雷侧针,该装置的安装过程能够进行带电作业,增加了供电可靠性,有效减少了线路绕击率,保证了线路安全运行。     

杆塔侧针用于500kV输电线路防雷效用模拟研究

为研究杆塔侧针对500 kV输电线路防雷效果的影响,首先通过3维电气几何模型的搭建,从理论上分析了侧向短针的工作机理以及影响因素。进而搭建实体模型用来实际模拟山区输电线路走廊,通过大量重复放电试验统计各工况下的试验绕击率。结果表明:加装侧针可以大幅度地降低雷电绕击率;侧针长度与安装角度对保护效果都会造成影响,即随着侧针长度的增加或安装角度的减小,绕击率呈下降趋势。试验较好地印证了理论分析结果,为塔头侧针在输电线路防雷改造中的应用与评估提供了参考依据和理论支持。     

复杂地形下输电线路绕击跳闸次数3维计算方法

实际线路参数超出其有效计算条件的范围时,传统耐雷性能评估方法便不能反映弧垂和输电线路走廊复杂地形对线路绕击耐雷性能的影响。为此,提出了一种计算分析复杂地形下输电线路绕击防雷性能的方法,该方法基于改进电气几何模型(EGM),考虑3维空间内导、地线相对于地面的高度变化以及输电线路走廊复杂地形的影响,以单个档距线路为研究对象,通过求取导线暴露面的水平投影面积来直接计算出该线路的绕击跳闸次数。以某复杂地形下的500 kV输电线路为例,绕击跳闸次数计算结果为0.000 77次/a,与实际运行数据相符较好。结果表明该方法能更准确简便地计算出单个档距输电线路的绕击防雷性能,并能较好地反映出线路走廊地形的影响,可为输电线路差异化防雷研究提供参考。     

500kV输电线路雷电绕击事故分析及预防措施

对近年来内蒙古500 kV包旗Ⅰ线地处山区的线路在雷雨季节频繁发生的绕击跳闸事故进行统计,采用改进电气几何模型(EGM)对包旗Ⅰ线绕击跳闸事故进行仿真分析,综合考虑海拔高度、地面倾角及风速对绕击率的影响,认为地面倾角、保护角、风速及雷电活动频繁是导致包旗Ⅰ线频繁发生绕击事故的主要原因,并提出采取提高绝缘水平、安装可控放电避雷针和防雷侧针及减小保护角的综合治理措施。     

500kV输电线路侧针防护效果的理论与试验研究

通过搭建三维电气几何模型,从理论上分析了侧向短针的工作机理以及影响因素。搭建输电线路实体模型来实际模拟山区输电线路走廊,并通过大量重复放电试验统计各工况下的试验绕击率。研究表明加装侧针可以大幅度地降低雷电绕击率,侧针长度与安装角度对保护效果都会造成影响。研究结果可以对塔头侧针在输电线路防雷改造中的应用与评估提供参考依据和理论支持。     

复杂地形下紧凑型输电线路绕击跳闸率计算方法

紧凑型输电线路正在得到日益广泛的应用,但对其在复杂地形下的防雷性能研究却很少。笔者提出了一种计算分析500 kV紧凑型输电线路绕击防雷性能的方法,并将其应用于输电线路的雷击风险评估中。该方法基于经典电气几何模型,考虑三维空间内导、地线相对于地面的位置变化以及输电线路走廊地形的变化,以一个档距为研究对象来计算分析输电线路的绕击防雷性能。以某500 kV紧凑型输电线路的一段线路为例,计算其在复杂地形下的绕击防雷性能,结果表明,该方法能更好地反映线路实际运行情况,并为输电线路差异化防雷研究提供了参考。     

500 kV紧凑型耐张杆塔绕击耐雷性能精细化分析方法

为了解决500 k V紧凑型耐张杆塔塔头结构复杂,传统绕击跳闸率计算方式无法准确计算此类杆塔绕击跳闸率的问题,通过建立500 k V紧凑型耐张杆塔精细化模型,提出了基于全档距绕击耐雷性能分析方法的紧凑型耐张杆塔绕击跳闸率分析方法,并研究了此类型杆塔在拆除分支地线前后绕击跳闸率的变化。分析结果表明,拆除分支地线后,杆塔的绕击跳闸率提高约16.3%,针对这种情况考虑加装塔头侧针来改善线路防绕击性能。研究结果表明,安装塔头侧针可以显著降低杆塔绕击跳闸率,当3个跳线横担均加装塔头侧针时,可使杆塔的绕击跳闸率降低约59.25%。研究成果对指导我国500k V紧凑型耐张杆塔防雷改造提供了重要的参考依据。     

降低输电线路雷击跳闸率的研究与应用

对输电线路空间落雷点绕击频次、避雷线保护角、输电导线电位、接地电阻等参数以及不同的地形地貌等环境因素对输电线路绕击概率的影响进行系统地研究,为输电线路防雷措施的研究提供了大量的试验数据.通过典型的220 kV输电线路(Z1型杆塔)在保护角为+17.下的缩比模型试验,得出雷电空间各点绕击频次的分布,为防绕击避雷针在输电线...     

贵州雷电活动及线路雷击跳闸情况简析

通过对贵州雷电活动及输电线路雷害情况进行实地调研,并对110～500kV典型线路模拟计算,获得了贵州省雷电活动的分布规律,以及贵州高压输电线路的防雷性能及存在的问题。     

基于雷电预警的UHVDC系统主动雷击防护策略

提出了基于降压运行和直流紧急功率支援的主动防护思路,分析了在特高压直流输电系统遭受雷击故障时2种方法提高电网安全运行能力的作用。利用PSASP建立了四川电网丰大运行方式下包含特高压直流输电通道的仿真模型,基于系统稳定性判据,仿真分析了雷击造成各条特高压直流输电通道单极/双极闭锁时,降压运行控制和直流紧急功率支援控制对送端电网安全稳定性的影响。研究结果对确保含特高压直流输电系统的电网安全稳定运行具有参考价值。     

Observation of lightning by means of time-of-arrival type lightning location system

LPATS—a lightning location system of time-of-arrival type—was installed in the middle of the Japanese island of Honshu by Tokyo Electric Power Co. in 1990. This system is LPATS Version III (LPATS III), which is the most widely used version of LPATS in the world, although there have been few reports on its operating characteristics. In order to utilize the outputs of this system to investigate lightning parameters, it is indispensable to identify its operating characteristics. The system was calibrated, and the observed distributions of the lightning current amplitude were analyzed and compared with previous reports. The results reveal that this system identifies negative return strokes in summer largely correctly, but in summer, it misinterprets many electric field pulses, originating from cloud discharges, as small positive return strokes. This result also suggests the strong dependence of the number of electric field pulses, associated with cloud discharges, on the polarity of the pulses. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(1): 9–15, 1997     

Experiments on lightning protection for automatic weather stations using artificially triggered lightning

This paper focuses on the voltages electromagnetically induced by the multiple return strokes involved in a triggered lightning on an overhead power line and a vertical signal line of an automatic weather station (AWS), and the backflow currents and residual voltages in a surge protection device (SPD) embedded in the power line. Pulses of voltage on the overhead power line corresponding to the return strokes with the peak currents ranging from −6.67 to −26.47 kA showed bipolar features. Subpeaks and main peaks ranged from 0.99 to 4.47 kV and from −4.98 to −10.31 kV, respectively. The voltage waveforms corresponding to the return strokes on the vertical signal line of wind speed were of two types: with and without a subpeak after the main peak. All the main peaks, with the peak value from −0.41 to −3.10 kV, were ‘V’ shaped. A significant relationship exists between the peak currents of the return strokes and the 10–90% average gradients of the voltages. The peaks of currents through the SPD ranged from −0.22 to −1.64 kA. The durations of residual voltages ranged from 0.6 to 5.9 ms, average value being 2.1 ms. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Study on the effectiveness of lightning rod tips in capturing lightning leaders

This paper addresses the performance of various lightning rod tips: pointed, concave, blunt, flat and conical for lightning air terminal (LAT). To observe the behaviour of the various lightning rod tips, laboratory examination was conducted under two conditions, i.e. corona emission pattern under quasi-static electric field and lightning impulse testing—with and without pre-ionization. The data obtained from the corona emissions were correlated to the surface sharpness area of the tip. Using dimensional analysis, it can be concluded there is strong evidence that increased surface sharpness can lead to an increase in the corona discharge current. In addition, an impulse test was conducted to determine the performance of the LATs with different tip types and sizes. Using the individual and competitive test, it was found that the blunt LAT is the most recommended receptor.     

再析避雷针(线)防直击雷作用

从影响避雷针（线）保护范围主要因素及其无法定量等方面说明了世界各国的避雷针（线）保护范围计算方法均是经验公式,并就GB 50057—1994选用外国经验公式提出质疑;同时指出避雷针（线）保护范围的绕击率除应经理论、实验室分析研究外还要靠实践运行统计分析得出,并分析了实际工程中不宜设置较高的独立避雷针（线）,非金属结构屋顶应用避雷网,不宜用避雷针的原因。     

雷击建筑物时的雷电流分布研究

建立了雷电流、雷电防护系统、配电变压器等配电网络的模型，利用国际通用的电磁暂态分析程序EMTP研究了TT系统（一种典型的低压与电系统）在遭受雷击时，雷电流在TT系统中的分布。并研究了单相和三相供电、不同波形的雷电流、传输线的线路阻抗对雷电流分布的影响。     

Winter lightning on Japan Sea coast-development of measuring systemon progressing feature of lightning discharge

With the aid of recent optoelectronic techniques, the authors have developed a measuring instrument named ALPS (Automatic Lightning Discharge Progressing Feature Observation System) to determine the progress of lightning flashes. The progress velocities of stepped leaders for lightning in winter seasons were observed using the ALPS in the coastal area of the Japan Sea. The progress velocity of an individual step of a stepped leader can be expressed by a lognormal distribution and its mean value is 1.6×10⁶ m/s for upward leaders and 4.0×10⁶ m/s for downward leaders. The mean progress velocity of a total leader process is given as 0.8~2.7×10⁵ m/s for upward leaders and 2.9×10⁵ m/s for downward leaders     

基于雷电定位系统的浙江电网线路雷击跳闸率评估

通过雷电定位系统观测的基础数据,评估浙江电网110～220 kV线路的雷击跳闸率,探讨传统雷击跳闸率算法的缺点,提出了算法改进的建议.     

Calculation of lightning current parameters

The new expression of the lightning current at the striking point is analyzed. The basic four channel-base lightning current quantities are assumed to be known: current peak value, current rise-time, maximum of the current steepness and the charge transfer at the striking point. The algorithm for a fast calculation of the channel-base current parameters is proposed. The numerical example of the current parameters determination is given. The proposed algorithm can be successfully used for the lightning current modelling in power engineering as well as in the research of the radiated lightning electromagnetic pulse and its coupling with the overhead lines and other metallic structures