特高压交流输电线路下方民房晾衣架感应电特性及改善措施研究

特高压线路电压等级高,空间电场容易造成附近居民生活空间的暂态电击现象,影响居民日常生活和电网环保性。其中,民房金属晾衣架处暂态电击现象频发,是居民投诉的重点。为此,建立了1 000 kV特高压同塔双回交流输电线路和金属晾衣架模型,分析了金属晾衣架上感应电势和感应电场的大小,并定量讨论了多种屏蔽线架设方式对晾衣架上感应电的降低水平和改善效果。研究表明：屏蔽线对改善线下金属物的感应电现象效果显著,最大降低72%;屏蔽线架设根数、与晾衣架的水平距离对改善效果影响较大。考虑施工和经济性影响,也提出了相应场景下屏蔽线架设建议。     

特高压输电线路电磁环境研究的matlab实现

利用matlab软件对交流特高压输电线路的工频电场、工频磁场进行了详细的仿真研究,分别介绍了仿真模型的建立方法和程序的具体模块,并采用算例进行仿真,仿真结果表明,避雷线对输电线周围电磁场没有太大影响,而导线对地高度越高,地面附近的电场强度越弱。由此结果可见,采用增加导线对地高度等措施可以减小输电线路下的工频电场。仿真结果对特高压输电线路的建设有一定的指导意义。     

交流特高压输电线路线下电场强度改善措施研究

提高杆塔高度,即提高导线对地高度,是控制交流特高压输电线路地面电场的主要方式之一。由于特高压线路跨越距离长,若大范罔地提高杆塔高度,将会较大地增加工程成本。特别是在某些环境敏感区域,当杆塔高度降低以后,由于导线对地距离减小,地面电场强度增大,有可能超过国家相关标准。因此研究降低线路地面场强的措施,如架设接地屏蔽线等方法．是交流特高压工程中急需考虑的技术问题。主要针对屏蔽线的不同架设方式对线路地面电场进行计算研究,通过分析比较各种屏蔽线架设方案下的场强水平,提出最优的屏蔽线架设方案。     

多回超/特高压交流输电线路平行架设及交叉跨越情况下的工频电场特性研究

为研究特高压输电线路与超高压输电线路平行架设及交叉跨越情况下的工频电场特性,基于有限元法,建立了超、特高压交流输电线路平行架设及交叉跨越时的数值仿真模型,分析了平行架设时输电线路的间距、对地高度以及相序对工频电场分布特性的影响;交叉跨越时输电线路的交叉角度、对地高度以及相序对于工频电场分布特性的影响,并以实例验证了模型的合理性。结果表明,导线对地高度对工频电场影响较大,随着交叉角度及线路间距的增大,两种架设情况下导线下方工频电场幅值逐渐减小,错序排列时线路下方高场强区域较少。     

无人机在特高压输电线路勘测中的应用研究

随着无人机技术的发展,采用无人机进行线路勘测将成为一种趋势。但微型多旋翼无人机搭载传感器有效像素仅约1 200万时,如何评估其航摄成果质量及提高其工效是亟待解决的问题。针对上述问题,基于特高压线路输电线路工程机载激光DEM数据和工测数据,对微型多旋翼无人机线路勘测数据的质量进行了评估,对其作业方法进行了改进。实践证明文章所提出的作业方法能为特高压输电线路勘测提供便携、可靠及高效的数据采集方式。     

山火条件下特高压直流输电线路合成电场研究

特高压直流输电线路在山火中火焰高温、火焰高电导率、固体颗粒物等因素作用下,容易导致输电线路周围电场发生显著升高,从而引发输电线路跳闸。为此,建立了山火条件下特高压直流输电线路合成电场非线性数学模型,该数学模型能够准确计算输电线路走廊发生山火时是否会引发输电线路跳闸,并以云广特高压直流输电线路为例,采用Comsol软件,分析了山火条件、正常运行条件和饱和电晕条件下地面合成电场。算例计算结果表明,山火条件下地面合成电场可达到正常运行情况下的33.6倍以上。     

超特高压直流输电线路电磁场对无人机安全距离的影响

近年来,利用无人机进行输电线路巡检已成为各运维单位的主要工作方式之一.同时,输电线路电磁场对无人机影响的研究也已逐步展开.在现有研究成果的基础上,结合本单位运维实际,对±500 kV及以上电压等级直流输电线路的电磁场进行了建模仿真,分析了无人机在该电磁场所受到的影响,得出了无人机巡检安全距离,其研究成果可为无人机现场作业提供可靠的技术支撑.     

国家电网发布1000kV特高压交流架空输电线路设计标准

国家电网公司日前发布并开始实施《1000kV交流架空输电线路设计暂行技术规定》等五项技术标准。这五项技术标准是我国1000kV特高压交流架空输电线路的主要设计技术原则。     

超特高压直流输电线路电磁场对无人机安全距离的影响

多旋翼无人机在超特高压直流输电线路中所需保持的安全距离是个亟待解决的问题.以多旋翼无人机和输电线路的实际参数为基础,以全电压、全电流的满负荷运行为条件,以ANSYS仿真软件为操作工具,经研究发现±500、±800、±1100 kV的电场和磁场所需保持的安全距离均有较大不同.综合判断此3种电压等级的安全距离分别为10.7、15.2、16 m.其研究成果可为无人机现场作业提供较为可靠的技术支撑.     

江西首条过境特高压输电线路赣江大跨越试桩

2011年1O月25日,江西首条过境特高压输电线路溪洛渡至浙西±800 kV特高压直流输电线路赣江大跨越正式试桩,试验基础工程开始混凝土灌注。溪洛渡-浙西±800 kV特高压直流输电线路是途经江西的第一条特高压线路,全长1679.9 km,途经四川、贵州、湖南、江西和浙江五省,江西境内线路路径465 km。该工程位于丰城市境内,自西北向东南跨越赣江。这次试桩工程开工,是溪     

我国发展特高压交流输电的必要性和可行性

回顾了国外特高压交流输电的研究发展历程,结合我国电网发展的实际,讨论了我国发展特高压输电的必要性、经济上和技术上的可行性,指出了我国发展特高压交流输电的必然趋势,建议尽快完善这方面的研究,从而启动1000kV特高压输电工程。     

Magnetic field of high‐phase order and compact transmission lines

Research has been conducted in high phase order (HPO) power transmission wherein 6 or 12 phases are used to transmit power in less physical space and with reduced environmental effects than conventional designs. In this paper, existing 3‐phase double circuit transmission lines (TL) are reconfigured to 6‐phase systems for the purpose of calculating and comparing the magnetic field of both systems. The magnetic field of several single‐phase configurations; flat, vertical, delta and inverted‐delta with the same degree of compaction is calculated and analysed at 1m height above the ground level. The magnetic field of the inverted‐delta arrangement, which showed the lowest field profile, is compared with the magnetic field of 6‐ and 12‐phase TLs having the same degree of line compaction and current loading conditions. The three systems are analysed when their lowest conductors had the same clearance to ground in one case and when their highest conductor positions were matched in another case. A comparison between 12‐, 6‐ and 3‐phase double circuit TLs having the same degree of compaction, the same phase voltage, the same clearance to ground and the same current per conductor is made to demonstrate if HPO lines reduce fields or not. The 6‐ and 12‐phase lines are raised while keeping their conductors within the space, which would be taken by the conductors of the double circuit line. In this case, the highest conductor positions of the two systems are matched and the magnetic field is recomputed to conclude the results. The vector magnetic field potential concept, as extended to HPO transmission lines, together with a flexible developed computer program are used to calculate and present the magnetic flux density components profiles around the mentioned systems. Copyright © 2002 John Wiley & Sons, Ltd.     

Electric field analysis of hybrid ac/dc transmission lines

In recent years, the possibility for ac and dc transmission lines running parallel to each other, sharing the same right‐of‐way (ROW) or even the same tower has been increased. Design of such hybrid ac/dc networks requires a precise calculation of the electric field around and under them. This paper presents quantitative analysis of the electric field at 1 m height above ground surface for different hybrid ac/dc transmission lines. Lateral profiles for typical Egyptian 500, 220 and 132 kV after adding bipolar dc lines are presented. The paper also considers reconfiguration of a typical 220 kV Egyptian double‐circuit ac transmission line, in which one of the circuits is converted into ±220 kV bipolar dc line. Different reconfiguration alternatives are studied to choose the optimum arrangement. The charge simulation method (CSM) employing the superposition principle is used to calculate the RMS value of the electric field generated by hybrid ac/dc lines at any point in the space. The RMS values of the field are determined directly without dividing the ac supply cycle into a sufficient number of subintervals as it has been done before. Satisfactory agreement with the results measured and calculated before by other techniques, for some typical ac/dc lines, has been obtained. Copyright © 2000 John Wiley & Sons, Ltd.     

特高压电网的过电压与绝缘配合

随着我国电力需求的快速增长,建设特高压电网已成为解决电网发展需求的必然选择。而限制特高压输电系统的过电压水平,合理选择绝缘水平是特高压输电工程建设的关键课题。从工频过电压、潜供电流、操作过电压、雷电过电压和绝缘配合这几方面全面分析了中国特高压交流电网的过电压与绝缘配合问题。分析认为,特高压交流输电在过电压及绝缘配合具有特殊性,但通过合理配置相关设备、优化线路和变电站设计可以满足要求,在技术上也是可行的。     

考虑大规模风电外送的半波长输电系统稳态电压控制方法

大规模可再生能源可以通过半波长输电线路实现远距离传输.本文针对考虑大规模风电外送场景的半波长传输系统提出了一种改进的稳态电压控制方法.首先,基于长线路分布参数模型推导出半波长线路特殊的电压分布规律.在二级电压控制层面,基于其电压特性,提出考虑对主导节点电压参考值跟踪的同时,通过限制半波长线路的无功传输实现对沿线稳态过电...     

SV-waves incidence at interface between solid-liquid media under electromagnetic field and initial stress in the context of three thermoelastic theories

In this article, we studied the propagation of SV-waves under the effect of electromagnetic field and initial stress for three models in thermoelasticity: The couple and Green–Lindsay theories as well as the dual-phase-lag theory. The problem of reflection and transmission of thermoelastic waves at a solid–liquid interface in the presence of electromagnetic fields and initial stress we investigated subjected to certain boundary conditions. The appropriate expressions to find the amplitude ratios of the incident waves (SV-waves) were obtained. The reflection and transmission coefficients for the incident SV-waves were computed numerically. The effect of electric field, magnetic field, and initial stress were illustrated graphically. Comparisons were made with the obtained results in the presence and absence of considered variables and displayed graphically. The results indicate that the effect of electric field, magnetic field, and initial stress on SV-waves incidence at the interface between solid–liquid media are very pronounced.