基于分布式光纤传感技术的智能电网输电线路在线监测

提出并研制了基于多参量分布式光纤传感技术的输电线路覆冰舞动监测方案。该技术能够对输电线路覆冰、舞动以及雷击等异常现象进行预警,从而实现对输电线路运行状态的在线安全健康监测。     

输电线路覆冰特征及其防治对策

输电线路覆冰是一种严重的自然灾害,可引发输电线路导线舞动、绝缘子闪络等事故,严重危害电力系统的安全运行。文中总结分析了输电线路覆冰的种类、性质及其影响因素,详细说明了由覆冰引起的绝缘子闪络和线路舞动的定义及防治方法,列举了现有的线路覆冰防治对策,为研究覆冰对输电线路的危害作了较全面的分析,有利于设计抵御冰灾的输电线路,提高了输电线路抵御自然灾害的能力。     

线路融冰工作的要点

冰雪凝冻灾害中,输电线路覆冰严重,为确保电网安全稳定运行和对用户的正常供电,应及时有效地对覆冰线路融冰.随着电网线路融冰方式的研究,线路融冰方式的不断革新,为我们应对冰雪凝冻灾害找到了方法.2011年当冰雪凝冻灾害发生时,瓮安电网对多条线路开展了融冰工作,现提出对融冰工作的注意事项.     

基于ZigBee技术的输电线路风荷载响应在线监测设计

输电线路风荷载是影响安全运行的重要因素,而在线监测系统是应对风灾害较好的方法之一。文中从风偏机理、风偏闪络的发生条件、风偏角典型计算方法等方面分析了输电线路风偏故障。提出一种基于ZigBee技术的输电线路风荷载在线监测系统,并介绍了系统的组成和相应功能。通过该系统采集的现场数据与风偏角典型计算方法得到的结果有较好的吻合。目前,该系统直接应用于贵州电网公司六盘水输电线路试验基地,可以有效地指导输电线路风荷载的运行维护管理。     

对输电线路覆冰特点及防冰技术的研究

输电线路覆冰危及电力系统安全运行,给人们生活带来不变,同时也会造成重大的经济损失.本文以防治输电线路覆冰事故为目的,从实际情况入手,分析了输电线路覆冰特点.然后,对一些防冰技术及其效用进行了分析,以期提高输电线路防冰能力,保护电力系统安全运行.     

基于惯性传感器协同１Ｄ ＣＮＮ的输电线路覆冰情况识别方法

输电线路覆冰是最常见破坏电网系统安全稳定运行的自然灾害。针对输电线路覆冰情况具有非线性增长、影响因素复杂等特点,提出了基于惯性传感器协同1D CNN的输电线路覆冰情况识别方法。该方法基于一维卷积神经网络,网络可自动从原始数据中进行特征提取和分类。采用集中质量法进行了输电线路覆冰的模拟实验,搭建了基于惯性传感器的输电线路模拟覆冰的三轴加速度的数据采集平台,构建了由三种线路覆冰情况：未覆冰、轻度覆冰以及重度覆冰的21824个样本组成的数据集,实验结果表明,基于惯性传感器协同1D CNN的线路覆冰情况识别的方法,性能优秀,平均准确率可达到91%。     

微地形区输电线路覆冰在线监测装置研究

严重的输电线路覆冰会造成断线、倒塔等事故,而严重的覆冰多处于微地形微气象区。通过对在线监测技术原理和输电线路覆冰理论的深入研究,针对微地形微气象区设计出一种新型的输电线路覆冰在线监测装置,解决了现有在线监测装置只能辅助人工巡视的局限性,并成功运用于输电线路,通过分析其采集数据验证了装置的可行性,可以更好地提高线路巡检工作效率和质量。     

架空输电线路覆冰不平衡张力的计算与分析

在输电线路运行过程中,由于恶劣气象条件造成的覆冰现象极易造成线路倒杆、断线及跳闸等事故发生,对电网的安全稳定运行造成极大的威胁。通过对线路覆冰不平衡张力的计算分析,就能够为提高输电线路安全运行性能的设计提供可靠的理论依据。本文将对架空线路的覆冰现象及其不平衡张力的分析计算进行探讨。     

浅谈输电线路的舞动及其防治

输电线路由于通常是架空布设的,虽然有杆塔或者其他固定措施,但是还是有很长一段是处于孤立状态,因此很容易受到外界因素的干扰。输电线路舞动就是指线路受到强风影响而产生剧烈的振动、摇摆,从而使得线路覆冰脱落不均,进而影响线路的稳定和电线的安全运行。本文笔者结合多年从事输电线路工作经验对线路舞动进行了探讨,分析了线路发生舞动的原因,并提出了一些解决防治措施,仅供参考。     

浅谈输电线路的舞动及其防治

输电线路由于通常是架空布设的,虽然有杆塔或者其他固定措施,但是还是有很长一段是处于孤立状态,因此很容易受到外界因素的干扰。输电线路舞动就是指线路受到强风影响而产生剧烈的振动、摇摆,从而使得线路覆冰脱落不均,进而影响线路的稳定和电线的安全运行。本文笔者结合多年从事输电线路工作经验对线路舞动进行了探讨,分析了线路发生舞动的原因,并提出了一些解决防治措施,仅供参考。     

配电线路中性线断线的原因及危害

随着社会的不断进步,电的作用越来越重要,而中性线又是保障整个配电系统正常运行的关键。文章从中性线作用及中性线断线的原因入手,并进一步分析了中性线断线给整个配电系统带来的危害,进而提出防范的措施。     

基于支持区域的直线段匹配

以往的直线段匹配算法都是利用直线段之间位置顺序的限制条件,而基于支持区域的直线段匹配算法则充分利用了图像本身提供的灰度信息。每条直线段的支持区域为直线段提供几何和灰度的特性值,这些特性可以通过加权作为匹配度计算的一部分。使用支持区域,直线段的匹配更客观、准确。     

主扰回路对失配被扰回路的耦合效应

利用积分方法分析了主扰回路对失配被扰回路的耦合效应,得到了计算被扰回路耦合电压的一般公式,将积分方法的使用范围拓展到了高频范围,并用经典的耦合干扰分析方法进行了验证,得出Klewe理论和Jarvis模型得到的结果是此一般公式的特例.该公式在低频和高频条件下均适用,并能将传输线的反射,损耗,相移和平行长度不相等都考虑在内.     

Low-loss open transmission line: the open ring line

A new low-loss line, the open ring line, is described. The aluminium-alloy structure consists of equally spaced rings held by a rod of the same metal. The measured attenuation for the hybrid dipolar mode is less than 5 dB/km below 1.8 GHz.     

Transmission line transformer

A transmission line transformer (TLT) with 50 Omega characteristic impedance on one side and approximately 5 Omega on the other side is described. It is small and rugged, and has a large bandwidth and low reflection coefficient. One of its applications is demonstrated, to improve the temporal response of a commercial high-speed photodiode as compared with a conventional 50 Omega coupling scheme.<>     

Product line competition

This paper studies product line competition in a simple model of a duopoly. There are two identical firms each of whom must choose a line of product qualities and supply quantities for each product in the line. They face consumers who prefer a higher quality product to a lower quality product but differ in how much they are willing to pay for quality. For the firms, a higher quality product is more costly to produce than a lower quality product. The basic question analyzed is the nature of product line competition. Will the firms choose to segment the market — one firm producing a line of lower quality products and the other firm producing a line of higher quality products — or will they interlace their products? Also, how is consumer welfare affected by these alternative ways of product line competition?     

New Tokaido line

This paper describes the technical features of the New Tokaido Line and is composed of seven sections. Section I presents the historical and social background of the construction of the NTL. Section II describes the technical and economic studies on the relation of the NTL to the existing narrow-gauge line and its social and economic influences, etc., which were used in making the fundamental decisions about track gauge, route, maximum train speed, motive power, etc. Section III presents the features of the operation control system. Section IV gives a comparison with the narrow-gauge line, describes the features of ground facilities such as the roadbed, bridges, tunnels, track, buildings, power source, overhead equipment, signaling facilities, and communication facilities, and mentions a study on high-speed train operation of similar facilities conducted by the Railway Technical Research Institute and on the test run section. Section V discusses the trend of traffic since the inauguration of the new line and the measures taken to solve the problems involved in the facilities in the face of an increase of traffic. Section VI describes the present state of maintenance of facilities and the problems involved. Finally, a general view of the planned New San-yo Line as an extension and improvement of the New Tokaido Line is presented in Section VII.     

Hierarchical line extraction

A hierarchical line and segment extraction algorithm, based on a pyramid, is described. Initially, lines are detected in small windows using the Hough transform. The detected lines are then merged using a distance criteria thus avoiding a reaccumulation process at each level of the pyramid. The hierarchical merging process is efficiently performed on lines rather than on segments (since there are many more segments than lines). The detected lines are broken into segments, at the top of the pyramid. The proposed approach is compared to similar approaches based on hierarchical feature extraction. The authors show that their approach combines the advantages of other works and avoids their drawbacks such as quantisation effect and lack of robustness