Real-Time Wind Speed Analysis at Wind-Damaged Tower of a Transmission Line

Affected by the Super Typhoon“Mangkhut,”a total of five base towers of a transmission line in the mountainous area of China collapsed.In this paper,a mathematical model is established based on the Shuttle Radar Topography Mission(SRTM)data near the accident tower.The measured wind speed in the plain area under the mountain is used as the calculation boundary condition.The wind speed at the top of the mountain is calculated by using a numerical simulation method.The design wind speed and calculated wind speed at the tower site are compared,and the influence of wind speed on tower position in this wind disaster accident is analyzed.

Design of 1000-kV AC Single-Circuit Overhead Transmission Line

The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage.There are no guidelines or standards available for the design of 1 000-kV overhead transmission line in China.Study on key technologies and design schemes shall be carried out to ascertain the technical principles and construction standards for project construction,which are presented in this paper based on the Southeast Shanxi-Nanyang-Jingmen test and demonstration transmission line.A comparison and analysis of technical data and economic indices between UHV line and other lines are also described.

Modification Method of Lightning Shielding Angle Calculation for Transmission Lines in Mountain Areas

Shielding angle is one of the main factors influencing lightning performance of transmission lines,which always stays in the focus of the design and the evaluation of lightning protection.A formula for the improved shielding angle is proposed for evaluating the lightning performance in different terrains.The digital elevation model(DEM) is used to obtain the micro-topography data,such as the slope gradient,slope aspect,etc.The following results are obtained by analyzing the influence of topography factors on the improved shielding angle:(1) improved shielding angle non-linearly increases with the increase of the slope gradient and the slope aspect,(2) improved shielding angle is more sensitive to the slope gradient than to the slope aspect,(3) the improved shielding angle in the mountain terrains is much greater than the designed shielding angle.This may be the reason why the designed shielding angle is limited into the rational range,while the shielding faults occur frequently.

Overview of development, design, testing and application of compact gas-insulated DC systems up to ±550 kV

The development of high-voltage direct current gas-insulated switchgear assemblies(DC GIS)of rated voltages up to±550 kV has been completed.DC GIS provide a compact technical solution with a high functional density,optimized for projects with limited space as in offshore HVDC converter platforms,onshore HVDC converter stations and transition stations between different transmission media.Up to now,no standards for testing of gas-insulated DC systems are available,although pre-standardization work is in progress within CIGRE.Some tests can be performed as required in AC GIS standards.Special aspects of DC voltage stress,like the electric field distribution of insulators influenced by the accumulation of electrical charge carriers and the operation-related inhomogeneous temperature distribution,must be considered by additional electric and thermoelectric tests.For DC GIS,the experience of long-term performance is limited today.Although ageing is expected to be of lower importance,tests are recommended.This contribution summarizes the physical and technical background to design and develop compact DC switchgear assemblies using gas-insulated technology.It explains the developed modules of the substation and gives an overview of the performed tests.Furthermore,it provides an insight in the on-going standardization activities and describes applications in converter and transition stations,showing its space-saving characteristics.

Investigation on Suspended Stripline and End-Coupled Bandpass Filter

In this paper, the variational method combined with Green's function is used to analyze the characteristics of suspended, stripline. The result is in good agreement with references. The design of mm-wave end-coupled bandpass filter with suspended substrate is discussed. The computer programs for design of suspended stripline and bandpass filter are established.

Minimum Curvature Design of Three-Element Centripetal-turbine Hydrodynamic Torque Converters

The influence of streamline bending inertia force on power loss is investigated.In order to analyze the combined effect of the inertia force and the path on the power loss,the accumulation effect expression of the inertia force on its path is derived.The calculation result shows that the accumulation effect of the unit inertia force on its path depends merely upon the velocity magnitude and the path scroll angle.As long as they are given,the accumulation effect is a constant and independent of the intermediate path.An important conclusion drawn is that the maximum inertia force rather than its accumulation effect plays a predominant role in the power loss.Thus,a new design method,minimum streamline curvature method,is proposed.Fluid particle movement inside a hydrodynamic torque converter can be regarded as curved movement on the circular surface and decomposed into a meridional component and a circumferential component.Each meridional streamline is designed to be close to a circular arc,while each torus streamline is constructed with a circular arc and a straight line segment.Based on the meridional streamline equation,the torus streamline equation and a streamlined thickness function,a blade surface equation of three-element centripetal-turbine hydrodynamic torque converter can be obtained.

Introduction of 500 kV Three Corges-Changzou Electric Power Transmission Project

To transmit electric power from ThreeGorges to East China, ±500 kV HVDC willbe adopted. The first transmission Iine will beconstructed from the Longquan (Yichang)Converter Station to the Zhengping(Changzhou) Inverter Station. This projectconnects the East China Power Network withthe Central China Power Network,coordinates the hydro and thermal electricpower, obtains the profit from timedifference and promotes the process of theinterconnection of the power networks of thewhole country.This paper gives the abstract of thesituation of the preliminary design, primaryresult and development tendency of the firstHVDC transmission project which transmitsthe electric power from Three Gorges to EastChina.

基于FSC和TCSC混合复用的交直流混联线路潜供电弧特性

为提高系统运行稳定性,高补偿度串补装置广泛投入使用,但线路故障后潜供电流存在高幅值的低频分量,潜供电弧难以自熄。针对此问题,基于交直流混联输电线路,研究了不同布置方式下串补度对潜供电流与恢复电压幅值影响,提出了一种固定串补(fixed series compensation,FSC)和可控串补(thyristor controlled series compensation,TCSC)混合复用抑制潜供电弧的方法。此外,为满足线路对高补偿度的需求,设计FSC和TCSC混合复用串补度最佳配置方案。结果表明,交直流混联线路采用串补度40%的双平台分散布置方式,潜供电流与恢复电压幅值达到最小,燃弧时间最短。高补偿度串补线路TCSC采用串补度10%、20%的配置方案更利于熄弧,提高重合闸成功率。

万泉河流域设计洪水分析

编制河流治理开发方案,需要合理可靠的设计洪水成果。以万泉河设计洪水计算为例,分析了历史洪水重现期,进行了水文站洪水系列一致性处理,建立了干流水文站之间的洪峰、洪量相关关系,插补延长了洪水系列,确定了水文站设计洪水成果。根据流域具有调蓄作用水库的兴建时间,计算不同分区的区间设计洪水。分析流域洪水遭遇情况,采用典型年法和同频率法分析设计洪水地区组成,采用分区时段洪量控制选取相对不利的典型年实测洪水过程为典型,推求防洪控制断面设计洪水过程线。

西藏地区“酒杯型”输电塔-线体系风致振动及风振系数设计研究

西藏地区地处高海拔、大风环境,近年来该地区输电线路频发风偏闪络等事故,且常见以体型不均匀的“酒杯型”输电塔相关线路较为频发。鉴于此,文中开展西藏输电线路工程的“酒杯型”塔—线体系风致振动及风振系数设计研究,旨在为相关输电线路合理抗风设计提供必要理论基础。研究过程和方法为:以西藏实际发生故障的“酒杯型”输电塔线路段为研究对象,采用输电铁塔及塔线体系的风致振动仿真分析方法,即利用Davenport风功率谱和AR法模型方法模拟脉动风荷载并施加于输电塔线体系有限元模型,结合随机振动理论计算输电铁塔的动态响应和风振系数;利用该方法对该输电线路进行仿真分析,探讨其塔线体系在强风环境下、不同风向角下的振动响应特征和风振系数影响规律;再将仿真结果对比现行设计规范,验证现行规范存在抗风设计不合理现象,亟需改进;基于此,文中提出输电塔—线体系的风振系数设计修正公式,整体误差10%以内,能准确反应西藏地区“酒杯型”输电塔相关线路的实际风振效应。文中研究为大风环境地区(西藏等)“酒杯型”输电塔合理抗风设计提供重要解决思路,具有较好的应用前景。

交直流输电线路混合电场的人体感受试验及设计控制值研究

交直流输电线路同走廊和同塔架设是随着我国电网技术发展而出现的新输电方式,国内外尚无相应的交直流混合电场设计控制值标准。因此,设计同走廊和同塔架设的交直流输电线路时,导线对地高度和走廊宽度的选取面临无据可依的难题。该文提出确定交直流混合电场设计控制值的原则;开展不同交流(工频)电场和直流电场组合下的人体直接感受和暂态电击感受试验;通过对试验结果的统计分析,获得不同概率下人体不出现明显感受时的交流(工频)电场和直流电场关系曲线;在此基础上,得出确定交直流输电线路混合电场设计控制值的公式。该研究可为同走廊和同塔架设交直流输电线路设计中交直流混合电场的控制提供一定技术支撑。

基于新型超宽带慢波微带传输线的设计

效率高、体积小、质量轻的微波无源器件是5G频段移动通信覆盖的必备设备。文中在研究传统微带型曲折线慢波结构和开路枝节加载基础上,提出基于超宽带慢波微带传输线的设计并进行研究,利用电磁场仿真软件HFSS对该慢波微带传输线进行模拟仿真,仿真结果表明,超宽带慢波结构与普通微带线相比,频带宽,尺寸小,损耗低,成本低,满足5G通信系统的需求。最后通过对加载了所提出的新型慢波微带传输线的小型化U型移相器的实验数据分析表明,该新型慢波微带传输线在基站天线系统中有着广阔的市场应用前景。

架空输电线路机械化施工设计应用概述

为推广机械化施工在工程咨询、设计和施工全过程的应用,结合架空输电线路机械化施工特点,从项目全过程设计流程入手,总结近年来机械化施工架空输电线路工程中的设计创新应用成果,提炼架空输电线路械化施工全过程设计要点,为后续架空输电线路机械化施工提升应用提供借鉴。

基于分段线性模型针对TLP瞬态干扰信号的芯片协同防护设计方法研究

集成电路芯片在高密度、小型化发展过程中产生了电磁兼容问题,为强化集成电路芯片对瞬态干扰信号的应对防护效果,可结合传输线脉冲(TLP)测试构建分段线性模型。文章首先对芯片应对瞬态干扰信号展开防护设计的现实需求进行分析,以CD4001BE芯片为例提出芯片TLP测试分段线性建模方式,总结瞬态电压抑制TVS二极管建模方法,并进一步展开芯片分段线性模型协同防护设计分析,旨为借助分段线性模型的方式控制芯片防护的设计时间与成本。

110 kV输电线路设计研究

结合实际工程,介绍110 kV输电线路的设计。通过前期设计人员对路径方案的规划对比,导线的技术经济对比,地线的远期配置,以及选择适应工程所需的杆塔和基础模型,来保证工程设计的质量更优。通过合理地选择线路路径、导线和地线参数、气象条件,进而合理地选取典型设计中的铁塔模块等,使得设计方案更合理,以达到工程经济技术指标更优,更加符合国家电网有限公司对输变电工程提出的“环境友好型、资源节约型”等方面的建设要求。

短路枝节加载微带传输线滤波器设计方法研究

对于微带线滤波器为代表的传输线滤波器设计,给定技术指标,如何快速准确地确定其拓扑结构和结构参数是其中的关键。由于分布参数效应,导致传输线滤波器设计比较困难。针对一种短路枝节加载微带传输线滤波器,深入研究了其物理机制,给出了解析设计方法。首先导出了滤波器的传输矩阵,接着通过cot变换关系对传输矩阵进行变换,最后将其与根据技术指标综合得到的理想传输矩阵进行比对,从而能够快速地确定滤波器的结构参数初始值。为了验证所述设计方法,设计了一个中心频率为3.0 GHz,绝对带宽为2.0 GHz,回波损耗小于-20 dB的三阶带通滤波器实例,并进行了加工测试。测试结果表明,理论、仿真和测试结果相吻合,验证了设计方法的有效性。

高速PCB传输线信号完整性设计要点研究

为了解决高密度、集成化高速PCB中传输线因走线空间有限,走线设计不当所带来的信号完整性问题,采用理论分析、经验值设计、仿真分析的手段对8层高速PCB设计进行研究.分析高速PCB走线设计对传输线反射、串扰等信号完整性问题的影响.在PCB布线完成后,通过SI⁃wave软件仿真对PCB传输线线宽、线间距和阻抗值大小对信号完整性的影响进行研究,验证设计经验值3 W间距和50Ω阻抗的可靠性.指导PCB信号走线设计,达到信号的完整性,以期为实际工程实践应用提供参考和借鉴.

输电线路杆塔接地电阻测量装置设计

输电线路杆塔接地电阻测量对于电力运维人员是一项繁重的工作。为了实现在不解开接地引下线情况下即可测量杆塔的接地电阻,文章设计了一种新型输电线路杆塔接地电阻测量装置,该装置采用双钳法对接地电阻进行测量。首先,分析了新型输电线路接地电阻测量装置的原理;其次,采用模块化设计思路对接地电阻测量装置进行硬件设计;接着,对接地电阻测量装置进行软件设计,给出系统工作流程;最后,对所开发测量装置进行测试,所开发测量装置的测量值与精密电阻实际值误差在3%以内。

交直流输电管道绝缘运行安全关键技术

交直流输电管道具有电压等级高、电磁辐射小、敷设灵活性强等优势,在超特高压输电领域弥补了架空线路和电缆铺设的局限性,具有广泛应用前景。影响输电管道运行安全的首要因素是绝缘故障,而其中两大重要诱因是内部微粒的荷电运动和气固界面的电荷积聚。该文系统化梳理国内外相关研究,包括微粒运动与电荷积聚的时空交互、微粒与电荷积聚耦合下的放电物理机制、绝缘子性能增强设计方法、微粒抑制技术等。在此基础上总结出亟待解决的两个关键难题以及需要攻克的技术瓶颈。针对荷电微纳粉尘随机动力学特性与其诱发微弱放电的物理机制,在测量基础上须突破粉尘可视化探测瓶颈,并发展粉尘动力学行为仿真方法,以及基于飞秒瞬态光谱特征的放电检测技术。针对基于电荷调控机制的主动式微粒活性抑制理论,须开发新型涂层材料的精准制备与稳定涂覆工艺,提出主动式微粒协同抑制方法,探索智能输电管道全生命周期数字孪生技术。上述问题的有效解决,可为提升交直流输电管道绝缘安全运行水平提供理论基础和技术支撑。