复合外套金属氧化物避雷器在110kV中悦线的应用效果

分析和介绍输电线路用复合外套金属氧化物避雷器（PMOA）的工作原理和功能及在110kV中悦线安装PMOA的使用效果，并提出PMOA是山区线路防雷，提高线路运行可靠性的有效措施。     

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.     

线路避雷器在广东电网输电线路上异常运行情况的分析

对广东电网应用线路避雷器作为输电线路防雷新措施实施9年以来线路避雷器所发生的异常运行情况进行了分析,包括了产品质量原因引起的故障、安装或选点不当等原因引起的运行异常以及自然灾害或极端气象条件引起的线路避雷器损坏等。总结了安装及运行经验,提出相应的对策,为线路避雷器这项新技术的推广应用提供了指导。     

Application studies of line arresters in partially shielded 138-kV transmission lines

The application of arresters on transmission lines has been one of the most effective alternatives for the reduction of lightning flashover rates. This paper reviews previous methods for evaluating lightning performance of lines with arresters. Improved calculations of line outage rates are developed to include power frequency voltage and arrester failure-rate evaluations, based on field experience. The transmission lines are modeled in detail in the electromagnetic transients program (EMTP)/(ATP) and the outage rates are calculated with the Monte Carlo method. Probability energy stresses on arresters are evaluated for strokes on conductors and shield wires as a function of tower footing resistance (TFR).     

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。     

Development of polymeric surge ZnO arresters for 500-kV compact transmission line

The 500-kV polymeric ZnO surge arresters for compact transmission line against lightning overvoltage were developed and have been put into operation, which consists of arrester unit and series gap. The design of the arrester unit, including structure design, selection of ZnO varistor, parameter determination, polymeric housing design, and mechanical structure design was discussed. The design of the series gap and the determination of the series gap length were presented. The calculated results state the line surge arrester can highly improve the lightning withstand level of the compact transmission line, and the line surge arrester can withstand the effects of lightning.     

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     

不换位线路参数不对称对距离保护的影响分析

不换位输电线路的参数不对称性,将会影响到基于参数对称为前提的保护的正确动作。为了研究参数不对称对于距离保护的影响,提出了不换位线路的序参数计算方法。在此基础上,通过理论推导和数字仿真,分析了阻抗继电器在各种故障情况下,不换位线路的测量阻抗的误差大小。据此,对不换位线路的距离保护整定计算提出改进建议。     

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     

线路避雷器在线路防雷上的应用效果

为了减少雷击对输电线路的伤害，将线路避雷器安装在输电线路的易击段，可以提高线路的耐雷水平。鉴此，介绍了线路避雷器防雷的基本原理和安装前的准备工作。并对近年来肇庆四会供电分公司部分已挂网运行的避雷器进行了跟踪分析，原多雷击杆塔自从加装了线路带串联间隙避雷器后，迄今杆塔未发生雷击跳闸。     

计及抗毁性的输电线路关键性综合评价

有效识别关键输电线路对预防大面积停电事故具有重要的意义。综合元件个体的抗毁性和对系统整体运行安全的重要性,提出了一种输电线路关键性的评估方法。从输电线路在系统正常状态下对负荷波动的承载力和在系统事故状态下对N-1开断的抗扰力2个方面综合衡量输电线路元件个体的抗毁能力;从输电线路对连锁故障产生和扩散所起的作用,来综合量化输电线路对系统整体运行安全的重要性;从输电线路的抗毁性和重要性来综合评价输电线路的关键性。IEEE 39节点系统算例和某实际电网算例验证了所提指标与方法的合理性和有效性。     

输电线路杆塔分流系数仿真计算

利用CDEGS软件针对220 kV/500 kV典型输电线路杆塔分别进行工频和雷电流模型的仿真计算,给出避雷线、杆塔地网、杆塔基础具体分流大小,分析影响杆塔分流系数的影响因素。     

考虑融冰因素的输电线路覆冰故障概率计算

根据导线覆冰表面热平衡方程分析内外部融冰因素对导线冰载荷的影响,计及地形对冰载荷的影响以及覆冰引起导线等效半径增大对风载荷的影响,通过气象实测的降雨量、风速、风向、温度等信息以及电网运行信息、当前监测覆冰厚度等信息建立输电线覆冰厚度增长预测模型。从输电线路覆冰过载机理出发,构建覆冰故障概率计算框架,从力学角度分析覆冰厚度及风速对输电线路的共同作用,采用反映金属承载极限特性的指数模型计算输电线路故障概率。以实际线路为例验证了该模型计算得到的线路覆冰故障概率变化趋势与实际故障情况相符,能够充分验证覆冰故障率与实际天气的相关性。     

Numerical analysis of overhead transmission line galloping considering wind turbulence

This study aims at clarifying the factors that cause transmission line galloping and the conditions influencing it, and at determining response evaluation indices of gallopings in turbulent flows. This is done using a three‐dimensional analytical method considering a large deformation. The analysis is based on four‐bundle transmission lines. Obtained results are as follows:

• 1 The occurrence of galloping in the smooth flow is limited by the combination of the following parameters: the initial angle of wind attack, the initial icing angle, and the wind speed. The galloping predominates mainly with one or two of the lowest in‐plane, out‐of‐plane, and torsional modes for the free vibration under the conditions that the transmission line is subject to dead load as well as static wind force. However, the galloping always occurs with torsional vibration.
• 2 The shape of the Lissajous figure for displacement depends on the initial angle of wind attack and the initial icing angle, as well as wind speed. The main shapes are vertically elliptic, horizontally elliptic, and a configuration having the shape of a horizontally rotated figure of eight.
• 3 The predominant frequency components of gallopings in turbulent flows are amplified and controlled by the turbulence intensity. Vibration frequency components unrelated to galloping increase linearly with rise in turbulence intensity.
• 4 There is a time lag of 30 s between galloping vibration and the fluctuating wind speed. The relationships between mean wind speeds and both trend components and standard deviations of galloping in turbulent flows closely correspond to those relationships during the smooth flow, and they can be obtained using the average time of 10 times the shortest vibration period of the transmission line. That is, the response values of transmission lines in the smooth flow can be utilized to estimate gallopings in turbulent flows. To estimate the maximum amplitude of a galloping, a peak factor of approximately 2.5 can be used. © 2000 Scripta Technica, Electr Eng Jpn, 131(3): 19–33, 2000

     

基于GIS平台对线路避雷器应用方案的研究

雷害是造成输电线路故障的主要原因.根据对110 kV及以上电压等级输电线路雷害事故发展过程的研究,使用线路避雷器将有效降低雷击跳闸率.介绍了基于GIS平台结合微地形情况的线路避雷器安装选点,提出了线路避雷器的应用方案,结合某220 kV架空输电线路进行实例分析,研究表明此方案直观、形象且易于对防雷措施进行管理,对实际防雷工程有参考价值.     

考虑时变故障率的架空输电线路最优巡检策略研究

目前输电线路的巡检周期多为固定性周期,不能根据线路的运行状态和环境状况进行及时调整,影响线路的供电可靠性和经济性运行。针对这一问题,给出了一种考虑时变故障率的架空输电线路最优巡检策略。以包括巡检成本、故障电量损失成本和维持可靠性的成本在内的综合目标效益函数最大作为指标,建立了基于遗传算法的线路巡检策略模型。为了得到更精确的效益函数,建立了非时齐马尔可夫时变停运模型,并结合蒙特卡罗可靠性仿真模型得到了可靠性指标,最后通过遗传算法求解出一个动态、周期可变的输电线路巡检计划。通过中部和东部两个故障率特征不同地区的实例计算,表明算法能根据输电线路的实际故障率大小进行巡检策略制定,并得到一个经济、合理、区域性、分季节性、动态可变的巡检周期计划。这避免了传统巡检过度和巡检不足的问题,能在获得较大经济效益的条件下,保证输电线路以较好的状态运行。     

增城110 kV线路避雷器运行效果分析

分析了线路避雷器的防雷原理．根据易遭受雷击的110kV线路采用复合绝缘外套金属氧化物避雷器后的实际运行情况,对避雷器投运前后线路跳闸数据进行分析对比。从而说明了线路避雷器确实具有一定的防雷效果。最后对线路避雷器的一些使用问题提出了建议。     

考虑线路有功传输约束的静态电压稳定分析

在求解电压稳定临界点的过程中,考虑了线路有功传输的系统静态安全运行约束,将电压稳定临界点的求取转变为非线性规划问题,建立以求解负荷裕度为目标函数的数学模型。采用对初值要求不高的非线性原对偶内点法求解已知负荷增长方向上的电压稳定临界点,该方法能够考虑各种等式和不等式约束条件,具有较强的鲁棒性。比较了考虑线路有功传输约束与不考虑约束两种情况下的支路功率,找到其中的薄弱支路。最后通过IEEE-30节点系统的仿真计算,验证了该模型及算法的有效性。     

考虑金融输电权的配电网阻塞管理

分布式电源高比例渗透和柔性负荷的灵活调度给配电网安全运行带来了极大挑战。分布式调度可以减轻配电系统运营商的运行难度,保障用户隐私,提升市场竞争。首先,建立了配电系统运营商和产消者之间的二次规划优化模型,采用基于迭代配网节点电价的分布式算法确定配电系统运营商和产消者之间的电价。其次,引入金融输电权概念用于平抑阻塞电价风险,防止节点阻塞费用补偿负作用于阻塞管理。最后在修改的IEEE33节点配电网测试系统上验证了所提方法在阻塞管理上的有效性。