高温超导电缆在城市地下输电系统应用的可行性研究

大城市有可能最先采用商业化运行高温超导电缆 ,用于城市地下交流输电系统。其主要应用目标是用于地下电缆工程改造 ,利用现有排管以高温超导电缆取代现有的常导电缆 ,增加地下电缆传输容量以及采用高温超导电缆将巨大电能 (1GVA以上 )输入到城市负荷中心。采用常导电力电缆传输 1GVA以上的电能进入中心城区 ,输电电压一般要求为 5 0 0 k V。在城市中心区不可能建设 5 0 0 k V变电站。 5 0 0 k V电缆线路所需的 5 0 0 k V大长度电缆和相应附件 ,目前尚未研制开发。采用高温超导电缆将有可能降低输电电压等级 ,可以采用 2 2 0 k V高温超导电缆将 1GVA以上的电能输入到城市负荷中心 ,满足特大型城市负荷中心供电需求。采用 110 k V高温超导电缆 ,亦有可能传输 1GVA左右电能。本文通过对交流高温超导电缆系列设计计算对额定电压 35 k V、110 k V、2 2 0 k V的高温超导电缆 ,按不同传输电流 (或传输容量 ) ,以高温超导电缆的传输效率 (损耗与传输容量比 )、高温超导电缆外径限值和超导导体绕制结构限制条件 ,确定高温超导电缆适用性界定条件 ,提出城市地下输电、配电系统用高温超导电缆可行方案。     

电力电缆技术的发展与研究动向

电力电缆广泛应用于城市电网中,经历了从充油电缆(OF电缆)、钢管电缆到交联聚乙烯电缆(XLPE电缆)的发展过程。XLPE电缆与其他电缆相比,有不需要供油、供气设备、防火性能好、安装维护简单等优良性能,被越来越多的国家所采用。电力电缆的安全运行关系到城市电网的安全可靠性,逐渐受到了各国的高度重视。提高高压电缆路径通道的管理水平、安全运行以及输送能力,其关键技术的研究非常重要。笔者叙述了电力电缆及其附件相关技术的研究状况和今后的发展趋势,得出提高城市电网的可靠性和安全性,降低运行成本是今后的发展趋势。     

Automatic balance of three-phase motor currents for variable motorloading using a static phase converter

For many years, single-phase static phase converters have been used to supply power to three-phase motors from single-phase distribution systems. However, the main disadvantage on many loads is that while virtually perfect current balance can be obtained at a given load, the balance cannot be maintained over a wide motor-load range. The results of using a patented balancing configuration that is integrated with a static phase converter are outlined. The auto-adjust controller offers many new uses for static phase converters in rural areas on pumps, compactors, and hammermills as well as in urban areas on elevators, lift stations, and compressors     

现代架空线输电系统中的高压电缆段(英文)

Electrical power transmission is dominated by overhead line systems at present.This is mainly based on more than hundred years of experience of utilities in running overhead lines.Furthermore,overhead lines have proven their operational reliability and functional assurance.In the past,cables were used in distribution networks in urban areas for the most part with the exception of direct current submarine cables.New developments of high voltage XLPE cables make it possible to use this technology for EHV level applications in transmission networks.Within this paper,mixed network configurations,consisting of overhead lines and high voltage cables,are investigated.An exemplary EHV transmission line with a total length of about 100 km,which is quite typical for Central Europe,has been studied.Several different line combinations are discussed with varied rates between overhead line sections and cable sections length in practice.The length of the cable sections are ranging from several kilometers up to lengths of 100 km.In this paper the work focuses on the transient behavior of combined 400 kV overhead and cable lines during switching processes and lightning impacts.A number of calculations were carried out to get an overview of the transient stress in numerous network nodes along the transmission system.Numerical programs like ATP/EMTP have been used for these simulations.Peak values and wave shapes of the transient voltage stress have been evaluated,based on different systems and within possible combinations.In respect of the insulation coordination and transient stress at network nodes,the voltage-time trends are also analyzed.The combination of high voltage overhead and cable transmission systems,especially such with lengths of more than about 50 km,are making tightened and extended demands to the network design,to the operational management and of course to the network protection also.As an output of this investigations,the results might influence the strategy in running this new type of combined transmission systems.     

P型环网结构的配电线载波组网方式研究

近年来,利用电力电缆屏蔽层载波通信传输配电自动化数据,是最经济、便捷和有效的一种可靠通信方式。城市小区普遍采用P型环网结构供电,采用电力电缆高频网桥耦合技术实现利用P型环网结构的电缆屏蔽层载波组网通信,是一种新的尝试,文章根据应用实例,通过现场测试多级分段电力电缆的屏蔽层信道的传输特性,分析载波组网通信效果,结果显示,利用多级分段电力电缆的屏蔽层载波通信传输配电自动化数据是可靠的。     

基于熵权理论的FAHP模型在城市配电网建设评价中的研究与应用

随着电力负荷和线路不断增加,城市配电网面临诸多生产压力和设备问题,电网企业经常通过实施城市配电自动化系统来解决上述问题;但由于其建设项目运行指标复杂,所以一般的评价方法难以准确给出评判结果.针对这一问题,提出了基于熵权理论的模糊层次项目综合评价模型.通过在具体电网中应用该评价模型,验证了其可行性和有效性,能够为实际配电...     

基于分布式无线TEV传感器的电缆终端局部放电监测系统

电力电缆是城市输配电系统的重要组成成分,其绝缘状态关系着城市供电的可靠性。局部放电检测是识别潜在绝缘故障的有效方法,可用于电力电缆的绝缘诊断。暂态对地电压法(TEV)是一种非电接触且应用较为灵活的局部放电带电检测手段,能够有效检测电缆终端或接头的局部放电。然而,由于电缆附件监测点分布较广,时效性要求较强且电磁环境差别较大,目前的TEV带电检测应用方法存在一定局限性。本文首先分析了电缆终端及接头处内部局部放电信号的时频特性,设计了能够有效耦合暂态对地电压的电容性TEV传感单元及信号预处理电路,并基于TEV物联网传感单元,建立了分布式TEV无线传感网络。本文对暂态对地信号的耦合原理、信号调理和采集、以及数据处理方法进行了研究,通过各传感节点放电量、趋势及模式识别,实现了关联故障预警。     

电力电缆在线诊断技术研究现状

叙述了电力电缆在线诊断技术的研究现状,根据充油电缆或交联聚乙烯电缆、电缆主绝缘、电缆接头及电压等级等不同,电力电缆绝缘老化的诊断技术可分为多种,其中,在线诊断技术不需电缆线路停运即可对电缆进行老化诊断,能真实反映电缆在运行电压下的工况。提出了电力电缆在线诊断技术未来的研究方向。     

Grounding effects of HV and MV underground cables associated withurban distribution substations

This paper derives a model for the evaluation of the performances of composite grounding systems of urban main distribution substations and associated power cable networks. The effects of the cables upon the dangerous voltages, transferred potentials and ground fault current distribution are encompassed including the conductive and magnetic coupling among grounding system elements, as well as the nonlinearity of cables sheaths impedances. An application example is presented, as are some experimental data     

高温超导电缆发展及其应用概述

随着高温超导技术的发展,高温超导电缆已经在输电系统中有了实际应用。与传统电缆相比,高温超导电缆具有传输容量大、损耗低、体积小、重量轻、可靠性高、节约资源、环境友好等优势,有望在未来电网发展中发挥重要作用。本文介绍了高温超导电缆的结构及特点、基本设计原理、传输电流与导体层电流分布及交流损耗等技术问题,并对高温超导电缆在交流和直流输电系统中的应用以及目前世界各国对高温超导电缆的研究及成果做了介绍。     

采用MATLAB仿真的变电站高压进线温度场和载流量数值计算

随着电力电缆在输配电线路中的广泛应用,准确确定电力电缆及其周围环境温度场的分布和电缆的载流量对于提高电力电缆的使用率、动态调整负荷具有重要的意义。为此,以地下排管敷设的交联聚乙烯电力电缆为研究对象,其实际模型为1个容量为250MVA、额定电压为230kV的变电站的高压进线。根据传热学和有限元法(finite element method,FEM)基本原理,建立了1种基于有限元法的水泥排管敷设电缆温度场计算模型,并对电缆及其周围环境的求解区域进行复合有限三角形单元剖分,即对电缆区域进行较密集的网格划分,而对电缆周围的土壤区域则进行较为稀疏的网格划分,以提高程序的运算精度和运行速度。结果表明:用MATLAB软件仿真,从而得到电缆及其周围环境的温度场分布,迭代计算了排管敷设交联聚乙烯电缆的载流量。证明使用有限元的方法分析地下电缆温度场,为电力工程中电缆载流量确定提供了一个比较可靠的计算方法。     

110kV交联电缆及附件的回收、再加工和利用

随着近年来城市电网建设力度的加大 ,市区 110kV变电所的重新布点可能导致运行年份不长的 110kV电缆停运 ,停运的 110kV电缆及电缆附件的回收、再加工和利用是城乡电网改造中的课题。     

在冰灾抢修特殊条件下的OPGW和ADSS施工工艺

光纤复合架空地线（OPGW）和全介质自承式光缆（ADSS）是电力部门使用的特种光缆,随着这两种光缆国产化率持续提高和生产规模急剧扩大,成本不断下降,由此得以广泛应用,目前是我国电力通信网的主要传输方式。本文简要阐述了OPGW和ADSS施工质量关键技术要求,详细介绍了贵州电力光缆在冰灾抢修过程中,因工期十分紧张、部分光缆受损区段地形特殊等情况而采取一些特殊工艺的具体案例。     

电力电缆的排管敷设方式

在城市电网建设中,电缆排管敷设方式具有优越性。建立了电缆排管敷设的载流量计算模型,计算得出了不同敷设方式下电缆的载流量;有针对性地就新型电缆保护管材在工程中的应用提出设计思路;对排管电缆工井的数量、长度、布置等要素分析论证,提出了解决工井排水的措施。文章可为电缆排管工程的设计和施工提供参考。     

Development of optical multidrop transmission lines and operation and maintenance technology for the full automation of power distribution lines

For the multimedia era, the authors plan to use optical fiber cables as the transmission media in integrated automatic distribution systems. This system provides a variety of advanced customer service functions and power distribution reliability features, such as remote metering, load control, and information service, including power consumption notification. The authors study an optical fiber multidrop network whose transmission path contains no active devices, using only optical fibers and optical couplers. The development of these passive optical networks must be accompanied by the development of useful components, maintenance methods, and operation procedures. The authors have developed ABF (air-blown fiber) composite power cables and optical branch boxes and have studied new optical network control procedures. They have also studied maintenance methods for optical multidrop networks, such as localization of obstacle points and charge-over switches for transmission paths. © 1997 Scripta Technica, Inc. Electr Eng Jpn 119(1): 24–34, 1997     

城市轨道交通用电缆的品种及应用

随着我国经济高速持续发展 ,城市轨道交通建设也在迅猛发展。轨道交通所使用的电缆品种繁多 ,本文对城市地铁、市郊铁路、城市轻轨用电缆系列产品作了介绍 ,包含产品名称、产品型号、应用场合以及选用时应注意的事项     

城市电网规划的认知性质与方法

提出了以认知系统工程理论指导城市电网规划及其决策支持系统开发的思想。强调了规划过程中人的主导作用,认为应重点解决人的信息获取与传递问题以及人与算法、人与人之间的协调问题。阐述了规划的性质和规划过程,指出规划乃是不同观点交互参与和反复修正,并互相妥协最终寻求一致的过程,它不可能单纯地由数学与计算机方法实现。提出了强适应性规划的任务,并总结出其实现的3个方法：采用鲁棒性强的模型与算法、多趋势规划法和再规划的方法。指出人在规划中的作用主要体现在：处理非技术因素和不确定因素造成的问题以及降低数学算法的计算复杂性,而为了充分利用人的智能优势,应当增强计算机决策支持环境的认知适应性。文中的一些观点和方法已在CNP 2.5的开发与应用中成功地采用,所得结论对工程决策问题有指导意义。     

城市配电网中电缆大规模接入条件下的无功优化方法研究

目前大型城市电网负荷低谷时段容性无功倒送现象日益凸显,危及电网安全稳定运行.基于此背景,研究了城市配电网中电缆大规模接入条件下的无功优化方法.首先,分析无功倒送对节点功率因数的影响,建立了考虑功率因数约束的含电抗器和电容器的综合无功优化模型,模型以有功网损最小为目标函数,在传统无功优化约束基础上增加了节点功率因数约束和...     

Event correlation

The advent of modern computer technology has enabled the development of many complex man-made systems. These include discrete manufacturing systems, communication networks, computer systems, traffic control systems, and inventory systems. A common characteristic of these systems is that they have discrete states (e.g., idle, processing, queue empty/full, and normal/faulty). Also, their state transition is triggered by events (e.g., part arrival/dispatch, alarms, commands, and timeout). For this reason, these systems are called discrete event systems or event-driven systems. As today's industry moves towards more complex, distributed and heterogeneous discrete event systems, there is a growing need for integration, consolidation, correlation, and distribution of the events coming from the systems. Event correlation achieves those objectives using methods borrowed mostly from artificial intelligence and formal methods. Historically, event correlation systems were developed for real-time monitoring of many classical mission-critical systems such as power plant and water/gas/oil distribution systems. Recently, it has been spreading into new areas such as messaging, network management and computer intrusion detection     

非开挖拖拉管在杭州电网电缆运行维护中问题的探讨

随着近年杭州经济建设和城市建设的快速发展,输配网络中地下电缆和设施越来越多。在地下空间资源日趋有限的情况下,非开挖拖拉管敷设方式也得到越来越广泛的推广应用。对杭州电网电缆非开挖拖拉管运维工作进行探讨,分析设计、施工、验收、运维等工作环节中存在的问题,提出切实有效可行的非开挖拖拉管电缆管线安全运行技术措施,确保深层地下空间的电缆管线安全。