消雷器与避雷针防雷特性的实验研究

介绍了对消雷器与避雷针的电晕电流、感应电流、保护区内外地面电场的测量方法和实测结果。消雷器和避雷针的电晕电流的实验值基本相同,并且均小于70微安。这一结果表明消雷器所提供的离子量不能在短时间内“中和”雷云电荷,不可能达到“消雷”目的,且消雷器和避雷针的防雷性能基本相同。并且通过分析雷暴全过程的地面电场的变化特点,为防雷预报工作提供了实验及理论依据。     

基于EGM的输电线路绕击跳闸率研究

电气几何模型(EGM)是计算线路绕击跳闸率的主要方法.本文在介绍电气几何模型原理的基础上,通过实证分析,研究输电线路直线塔绕击跳闸率,最后给出满足防雷要求的杆塔选型建议.     

浅析输电线路有效防雷措施

文章通过分析高压输电线路雷击闪络跳闸产生的原因,在进行线路防雷工作时,提出一些合理有效的防雷措施,以提高输电线路的耐雷水平,降低输电线路的雷击跳闸率。     

湖州地区输电线路防雷分析

论述了湖州地区历年来的雷击及线路跳闸情况,并对雷击输电线路的原理以及采取相应有效的防雷措施及效果进行分析.     

线路避雷器在线路防雷中的应用

阐述和分析线路避雷器的原理,并介绍线路避雷器安装、试验等方面的技术知识,以及有效的措施。     

湖州地区输电线路防雷措施的选择

高压架空输电线路的雷击跳闸故障是影响电网安全供电的一个难题.当今雷害事故几乎占线路全部跳闸的一半或更多,因此掌握湖州地区雷害现状,并采取有效的线路防雷保护措施是确保湖州电网安全可靠运行的重中之重.文章论述了湖州地区历年来的雷击、线路跳闸情况和现有的防雷措施,对雷击输电线路形成的原理以及现阶段采取的防雷措施进行效果分析,并提出改进措施.     

10kV输电线路综合防雷措施

10kV输电线路雷害事故频繁发生,严重危害输电网的供电可靠性和电网安全,影响人民群众的生产、生活用电。本文结合10kV输电线路运行的雷害发生情况,研究了10kV输电线路的防雷保护措施具有相当重要的工程实际意义。     

高压输电线路雷击跳闸故障的判别

对输电线路不同的雷击事故进行分析,提出了雷击跳闸故障的判别方法。     

消雷器消雷的理论分析

根据电磁学基本理论,阐述消雷器的作用原理、接地问题以及有源离子消雷器。     

架空输电线路防雷问题探讨

电力系统是国民经济的命脉所在,稳定运行的电网对确保企业生产安全和人们工作、生活顺利均具有十分重要的意义.若要保障电网运行正常,就必须对影响其稳定运行因素进行探究,并找出解决的办法.本文对影响电网安全运行的架空输电线路防雷问题进行深入探讨.     

输电线路防雷评价模型及管理系统设计

通过相关影响线路耐雷水平各项因素分析,并借助计算机辅助设计管理系统,建立防雷评价模型,得到综合比较整体评价结果,同时以某一改造工程实例加以验证,从运行情况看,改造后的线路工程达到了预期目标,有效地减少了线路雷击.     

A new type of Wilkinson dual-frequency power divider with symmetrical transmission line stubs

To realize equal power splitting at two arbitrary gigahertz-frequencies, this paper presents a new type of Wilkinson dual frequency power divider, consisting of three-section transmission lines and a series RLC （resistor, inductor and capacitor） circuit. By equating the [ABCD] matrix of the proposed circuit to that of the quarter-wave impedance transformer, coupled with even/odd mode analyses, the design equations of the proposed network are derived. For verification, two dual-frequency power dividers with dual-band operating frequencies at 0.6 GHz and 3.0 GHz, and 3.8 GHz and 10 GHz respectively are designed and simulated. Simulation results show that the dual-band ratio of the proposed power divider can be as large as 5. Comparisons of the simulation results at X-band and S-band with different power dividers indicate that the proposed dual-band power divider performs better under the scenario of the upper operating frequency extending to X-band.     

雷电对供电系统和电器的危害分析及防御

雷电是常见的天气现象，近几年随着电器电子产品日益增多，雷电对电器的危害造成的经济损失呈上升趋势。本文分析了雷电的形成及雷电对供电系统和电器的危害。提出了完善供电系统的防雷避雷措施能有效保护电器免遭雷击。对避雷器工作原理和避雷方法作了分析介绍。     

实验室精密仪器设备防雷电及过压保护系统研究与实施

雷电及过电压对实验室精密仪器设备的危害很大,轻则造成数据损失、控制设备误操作,重则毁坏设备。雷电危害实验室精密仪器设备主要通过电源线路和各种数据线缆以及地电位反击。因此,防止雷电危害应采取综合措施,做好各种线路的防护和等电位处理,给出了防雷的具体方案。     

基于直线型滑移索单元的输电线路结构张力分析

为了研究高压架空输电线索结构与塔架等其他杆件连接处的滑移特性,定义了一组滑移索单元,由一个通过滑动节点连接的三节点活动滑移索单元和多个两节点非活动滑移索单元组成．基于更新拉格朗日格式推导了三节点直线型滑索单元几何非线性刚度矩阵,并通过两跨和三跨等高连续索结构的有限元数值算例验证了空间直线型滑移索单元的有效性．研究结果表明,推导的直线型滑移索单元张力与已有计算结果相比,误差在1％以内．考虑滑移的索结构初始平衡状态内力与不考虑滑移的情况比较相差较大,因而在实际工程中应该考虑索的滑移．     

Effects of un-transposed UHV transmission line on fault analysis of power systems

The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method with the symmetrical distributed parameter circuit model as the equivalent circuit of the un-transposed ultra high voltage (UHV) transmission line were studied under both normal operation and fault, and the corresponding problems arising were pointed out. By contrast with electromagnetic transient and power electronics (EMTPE) simulation results with the asymmetrical distributed parameter circuit model of un-transposed line, it is shown that the conventional method cannot show the existence of negative and zero sequences before fault happening and there are many errors on voltage and current after fault happening which are different with fault types. The error ranges of voltage and current are 2.13%-81.13% and -7.82%-86.15%, respectively.     

Numerical analysis on aeolian vibration of transmission lines with Stockbridge dampers

We used computational fluid dynamics （CFD） and mode superposition method instead of the energy balance method to compute transmission line aeolian vibrations induced by the Karman vortex. Firstly, we obtained the wind power inputs using CFD theory. The result is effective for aeolian vibration analyses compared with the power which were measured in wind tunnel tests. Then a new aeolian excitation was derived using the wind power equivalent principle, and the aeolian vibration distribution along transmission lines and the wind power input obtained by CFD can be account. Secondly, we formulated the motion equation of a conductor-damper system and derived a semi-analytial solution using the mode superposition method. The Stockbridge-type dampers attached were simplified to the forces transmitted by the clamps. Finally, the semi-analytical solution can be solved by iterative methods. Taking a 1 000 kV Ultra High Voltage transmission line as an example, we analyzed the line with and without dampers by the semi-analytical solution. Compared with the results which were computed by the energy balance method, the semi-analytical solution is precise enogh for aeolian vibration analyses. Besides, we also analyzed the influence of damper position and quantity.     

高压输电线路导线跌落非线性动响应分析(英文)

为了研究机械性故障对高压输电线路耦合体系的受力影响,建立了输电线路耐张段的非线性耦合体系模型,通过导线找形非线性静力计算确定了耐张段的初始平衡状态.采用瞬态动力分析方法计算了导线、绝缘子破坏失效危险工况下的输电线路耦合体系非线性动响应.分析结果表明,上横担一组导线断裂失效对邻近端导线张力没有明显影响,对邻近端的绝缘子及铁塔横担构件的受力有较大的影响;上横担一组绝缘子破坏失效后,破坏档未破坏端导线的张力超过了技术规程中的设计值;导线的跌落对破坏档未破坏端的上横担绝缘子受力有较大的影响,而对上横担铁塔杆件没有明显的影响;在架空送电线路的设计中应该考虑绝缘子断裂的荷载工况.研究成果可为输电线路结构设计提供理论依据.     

基于LCL-S型谐振的大功率无线电能传输实验平台设计

该文在深入分析无线电能传输技术的传输特性及其磁耦合式传输工作原理的基础上,基于LCL-S型谐振耦合原理设计了一套大功率无线电能传输实验平台.首先,利用互感耦合模型对平面型系统机构进行了电路分析;其次,搭建了该实验平台的骨架构造;最后进行了实验测试,完成了双脉冲试验、开环控制带载试验和闭环控制带载试验等,分析了谐振频率对...