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输变电工程中通过对电力金具的压接实现架空导线的连接,压接电缆的弯曲度是衡量压接质量的重要参数之一.文中根据压接电缆自身特点,提出了一种基于图像处理的弯曲度自动测量方法.利用压接图像的灰度跳变自动确定压接电缆的压接区域,通过检测Harris角点,并结合图像的灰度特征确定拟合点,采用二次曲线拟合对压接电缆的弯曲形状进行逼近,进而算出压接电缆的弯曲度.对实际压接电缆进行测试,实验结果表明,该方法可完成对弯曲度的快速自动测量,且适应不同光照强度,能有效地消除毛刺点对测量结果的影响,符合压接工艺规程对测量的精度要求. 相似文献
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《贵州电力技术》2018,(11)
交联聚乙烯绝缘电缆在铺设过程中弯曲产生的压力会造成电缆损坏。为了在日常检测维护中检测电缆是否发生不合理的弯曲形变,本文提出了一种利用深度图像电缆曲率测量方法。本方法基于飞行时间(ToF)技术获得关于测量环境的深度图像,先对光源进行调制,再向周围环境发射调制光源,成像传感器通过接收与调制光源从而计算出深度图。再选定深度图中电缆上三个点就可以利用三点法对待测部位进行曲率计算。实验通过在不同位置对同一段的电缆进行曲率测量,测量曲率误差在±0. 03m~(-1)内,符合实际测量要求。本方案具有实时性、误差范围小、人机交互友好的优点,同时本测量应用无需仪器安装、操作的相关专业知识经验,集成度高,便于携带,适用于多种电缆曲率测量场景。 相似文献
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新型电缆绝缘电阻在线测量系统的研制 总被引:1,自引:0,他引:1
论述了一种新型电缆绝缘电阻在线测量系统的研制。在体系结构上,系统采用了硬件层、协议栈层、操作系统层、应用层等4层结构;在组网方式和硬件上,系统采用分布式结构,通过CAN总线最多可连接255台测量仪,每台测量仪由底板、主板、取样板、继电器阵列板和电源板等5类12个模块组成;在软件上,系统以嵌入式实时操作系统uC/OS—Ⅱ为内核;在功能上,每台测量仪可测63芯电缆中任意两者问以及任一芯对地的绝缘电阻;在理论上,提出了相关测量精度、灵敏度、分辨率等关键技术的实现方法。 相似文献
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本文分析了影响V/I法高阻测量精度的主要因素,设计了以单片机为核心的高阻测量仪。采用加压测流的方案,运用双屏蔽输入电缆、优选输入级器件、隔离等关键技术,使电阻测量可达10^6Ω,电流测量可达10^-13A。 相似文献
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空间电荷现象严重制约着高压直流塑料电缆的发展。目前,脉冲电声法(pulse electric acoustic,PEA)是国际上常用的测量固体电介质中空间电荷分布的非破坏性的方法之一。首先从高压脉冲的注入方式出发,简述了几种基于PEA法的同轴塑料电缆空间电荷测量技术;同时,提出了一种基于高压脉冲从测量电极注入电缆试样的改进测量装置,在该装置中通过蓄电池、环氧底座以及光电转换器等将采集数据的示波器进行对地隔离,从而提高了测量系统测量信号的频带宽度;然后,介绍了同轴塑料电缆空间电荷波形的恢复方法;最后,概述了空间电荷测量技术在评估电力电缆老化程度中的应用和未来在线测量空间电荷的可行性及发展方向。 相似文献
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Mugala G. Eriksson R. Gafvert U. Petterson P. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2004,11(3):471-480
Knowledge on the dependence of wave propagation characteristics on material properties and cable design is important in establishing diagnostic methods for cable insulation. In this study, a high frequency measurement technique to characterize the semi-conducting screens in medium voltage cross-linked polyethylene (XLPE) cables has been developed. The frequency ranges from 30 kHz to 500 MHz. The influence of the experimental set-up, sample preparation methods, pressure and temperature are investigated. A dielectric function is developed for the semiconducting screens and this is incorporated into a high frequency model for the cable. The propagation characteristics obtained from the high frequency cable model are compared with those obtained from measurements made on the same cables. 相似文献
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Sobral S.T. Horta Santos J.J. Mukhedkar D. 《Power Delivery, IEEE Transactions on》1988,3(4):1403-1409
It was previously reported that when a fault to ground occurs in a substation fed exclusively by power cables, around 98% of the fault current can flow along the cable sheaths and auxiliary underground conductors, producing no local potential rise. This can modify greatly the results of ground measurements carried out in this type of substation, unless special care is taken and correction factors are suitably applied. The authors extend the experience gained during those measurement and determine a set of procedures that allow ground measurements to be made in substations fed solely by power cables. They set forth basic requirements for the measuring circuits and for handling the measured data. They then discuss power cable sheath characteristics in some step-down urban substations and ground measurement strategy for such substations 相似文献
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Kreuger F.H. Wezelenburg M.G. Wiemer A.G. Sonneveld W.A. 《Electrical Insulation Magazine, IEEE》1993,9(6):15-22
Errors in partial discharge (PD) location on high voltage dielectric cables caused by both mechanical and electrical phenomena are discussed. The sources of error relevant to PD location include errors in measuring time delays, scatter caused by noise and disturbances, pulse propagation distortion, errors in cable length measurement, and trivial errors in experimental technique. Experiments to determine typical PD location error were carried out using a detector with a 10 MHz bandwidth. Extensive tests were carried out on a 200 m, 15 kV cable with metering marks on the outer sheath, as well as a 590 m, 10 kV cable without metering marks 相似文献
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Oyegoke B. Hyvonen P. Aro M. Ning Gao 《Dielectrics and Electrical Insulation, IEEE Transactions on》2003,10(5):862-873
Water treeing is one of the factors leading to failure of medium voltage XLPE cables in long-term service. Increased moisture content inside oil-paper insulated cable is not desirable. To identify water tree degraded XLPE cables or oil-paper cables with high moisture content, diagnostic tests based on dielectric response (DR) measurement in time and frequency domain are used. Review of individual DR measurement techniques in the time and frequency domains indicates that measurement of one parameter in either domain may not be sufficient to reveal the status of the cable insulation. But a combination of several DR parameters can improve diagnostic results with respect to water trees present in XLPE cables or increased moisture content in oil-paper cables. DR measurement is a very useful tool that reveals average condition of cable systems. However, it is unlikely that DR measurement will detect few, but long water trees. In addition, DR cannot locate the defect or water tree site within the cable system. Combination of DR and partial discharge (PD) measurements can improve diagnostic results with respect to global and local defects. However, it is doubtful whether PD test can identify the presence of water trees inside a cable in a nondestructive manner. Further research is needed for more detailed conclusions regarding the status of a particular insulation and for predicting the remaining life of the insulation system. 相似文献
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EMP作用下的电缆耦合及屏蔽效能试验分析 总被引:1,自引:0,他引:1
介绍了三同轴法、线注入法、功率吸收钳法、混波室法等电缆屏蔽效能测试方法.进行了电磁脉冲作用下的同轴电缆和裸线耦合试验,探讨了该环境下同轴电缆屏蔽效能的测试方法.试验分析表明,电缆耦合后的波形为衰减振荡波,振荡周期正比于电缆的电长度,频谱与照射场的频谱不一致,裸线的耦合输出衰减较快.根据试验数据,采用峰值场强法计算的电缆屏蔽效能与峰值电压法的结果吻合,所以可采用峰值场强法对电缆进行电磁脉冲的屏蔽效能测试.电磁脉冲作用下的同轴电缆屏蔽效能较相当频段连续波作用下的略低. 相似文献
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基于弹性工程磁学理论的索张力测试的研究 总被引:1,自引:0,他引:1
本文介绍了弹性工程磁学的基本理论以及利用弹性工程磁学进行索张力测试的基本原理,设计了基于弹性工程磁学原理测试索张力的仪器并对该仪器做了介绍,进行了索张力测试的试验研究,介绍了试验内容并对试验结果进行了整理分析.试验结果表明不同应力下,磁导率有明显变化,且可测,这就证明了通过测试不同拉力下的拉索材料的磁导率反映可以测量拉索所受拉力的大小. 相似文献