高电压输电线路雷电监测系统研究

发布时间：2018-03-01 07:36

本文关键词： 输电线路雷电流过电压在线监测电源屏蔽结构　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：在电力系统中，由雷电引起的架空输电线路故障比例很大。在输电线路防雷研究方面，研究工作主要是实验室模拟与软件仿真分析，但是输电线路模型并不十分完善，计算分析结果与实际情况明显不符，而输电线路各研究方向又缺乏真实的雷电参数，研究工作迫切需要对输电线路真实的雷电参数进行监测，以获取雷击输电线路的原始信息。通过输电线路雷电的监测，统计雷击输电线路的雷电分布规律，分析事故、改进绝缘配合等具有重要的意义，结合实际输电线路的结构，也有利于开展电晕、冲击、衰减等理论研究。本文提出了一套新型的基于双参量测量的雷电监测方法，不同于现有输电线路雷电监测系统只对雷电流进行监测，参数单一，新方法分别对输电线路雷击入地电流和输电线路雷击过电压双参量进行监测，，多参量监测能够提供更多细节，对雷击过电压分类识别提供数据支撑。新型监测系统采用分布式结构，兼顾独立运行与组网监测，监测设备全部模块化，方便监测系统维护与扩展。在雷电时间分布与日照规律统计分析基础上，提出了监测系统工作模式，通过实验分析，得出监测系统各设备运行状态，总体功耗，适用时间，以及切换条件。比较国内外各种取能方式，阐明了监测系统采用太阳能供电的理由，结合工作模式与取能方式实现全年稳定运行，通过实验证明监测系统能够准确获取雷电电压、电流参数。本文提出了一种新型的用于还原多通道原始雷电流波形的电流传感器，基于罗氏线圈的基本原理，结合不同电压等级的杆塔结构，通过在杆塔塔脚配置四并联罗氏线圈来还原真实的雷电流波形，在此基础上构建电流传感器计算模型，通过Saber软件仿真电路模型，验证了计算模型的准确性和可行性，结合安装位置，分析了载流体形状、安装偏移对传感器精度影响，通过冲击电流实验验证了电流传感器的测量性能与精度。电压传感器采用重庆大学研制的非接触式输电线路过电压传感器，针对工程应用，对该传感器结构，高压臂电容计算公式做了相应改进，结合电压传感器频谱宽的特点，提出利用工频电压对传感器进行动态标定，将影响因素直接计入分压比的方法。雷电监测装置安装在高压输电线路附近，周围环境复杂多变，容易影响装置的正常运行。本文对雷击输电线路暂态过程进行了分析，通过在仿真计算，选择合适的屏蔽材料与传输电缆，根据暂态分析结果提出测量系统接地方式，设计了安全可靠的安装结构，实验结果表明，监测系统具有良好的抗干扰能力和可靠性。
[Abstract]:In power system, the proportion of overhead transmission line faults caused by lightning is very large. In the research of transmission line lightning protection, the research work is mainly laboratory simulation and software simulation analysis, but the transmission line model is not very perfect. The results of calculation and analysis are obviously inconsistent with the actual situation, and the research direction of transmission lines lacks of real lightning parameters, so the research work urgently needs to monitor the real lightning parameters of transmission lines. In order to obtain the original information of lightning strike transmission line, it is of great significance to analyze the lightning distribution law, analyze the accident and improve the insulation coordination through the lightning monitoring of the transmission line, combining with the structure of the actual transmission line. It is also conducive to the development of corona, shock, attenuation and other theoretical research. A new method of lightning monitoring based on dual parameter measurement is proposed in this paper. Different from the existing lightning monitoring system of transmission lines, the lightning current is only monitored and the parameters are single. The new method monitors the double parameters of lightning strike ground current and transmission line lightning overvoltage respectively, and multi-parameter monitoring can provide more details. The new monitoring system adopts distributed structure, takes into account independent operation and network monitoring, and the monitoring equipment is all modularized. It is convenient to maintain and extend the monitoring system. Based on the statistical analysis of lightning time distribution and sunshine law, the working mode of the monitoring system is put forward. Through the experimental analysis, the operating state, the overall power consumption, the applicable time of the monitoring system are obtained. As well as switching conditions, compared with all kinds of energy acquisition methods at home and abroad, explained the reason why the monitoring system adopts solar power supply, combined with the working mode and the energy acquisition mode to realize the stable operation of the whole year. Experimental results show that the monitoring system can accurately obtain lightning voltage and current parameters. In this paper, a new type of current sensor used to restore multichannel original lightning current waveforms is proposed. Based on the basic principle of Roche coil, the structure of pole tower with different voltage levels is combined. By installing four parallel Roche coils on the tower foot to restore the true lightning current waveform, the calculation model of the current sensor is constructed, and the accuracy and feasibility of the calculation model are verified by the simulation circuit model of the Saber software. Combined with the installation position, the shape of the loaded fluid and the effect of installation offset on the accuracy of the sensor are analyzed. The measurement performance and accuracy of the current sensor are verified by impulse current experiment. The voltage sensor is based on the non-contact transmission line overvoltage sensor developed by Chongqing University. The formula for calculating the capacitance of high-voltage arm is improved accordingly. Combining with the characteristic of spectrum width of voltage sensor, a method of dynamic calibration of the sensor by using power frequency voltage is put forward, and the influence factors are directly taken into account in the ratio of partial voltage. The lightning monitoring device is installed near the high voltage transmission line, the surrounding environment is complex and changeable, and it is easy to affect the normal operation of the device. The transient process of lightning strike transmission line is analyzed in this paper. According to the results of transient analysis, the grounding mode of the measuring system is put forward, and a safe and reliable installation structure is designed. The experimental results show that the monitoring system has good anti-interference ability and reliability.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM863

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