基于毫米波技术的绝缘子在线监测研究
2023-01-07 23:03:28
论文总字数:17015字
摘 要
绝缘子作为电网中最常用最重要的电气部件,在高压输电工程中承担着电气绝缘、机械支撑作用。如果绝缘子发生任何故障,就会引起供电中断或者停电的现象,会对电网造成严重损害。而且绝缘子又长期暴露在空气中,外界环境复杂多变,很容易对绝缘子造成不良的影响。绝缘子的良好状态关系着特高压电网的安全运行。并且电网对绝缘子可靠性要求极高,需求量也是巨大的。因此绝缘子裂纹的在线监测研究的意义重大。目前,传统的检测方法利用无人机巡视、工人现场用仪器检测,这些方法会存在安全系数低、准确性底和高成本等问题,因此本文提出用毫米波技术对绝缘子进行实时监测,保证了绝缘子的可靠运行。
本文结合太景科技(南京)有限公司的毫米波传感器的相关技术和该公司提供的绝缘子检测实验平台,实现特高压输电工程中的大吨位瓷绝缘子裂纹高效检测的目标。针对绝缘子的自动识别感知、定位和检测等问题,验证了该公司提出的一种基于毫米波技术的绝缘子在线监测技术。为了模拟绝缘子产生微裂痕的过程,该公司设计出了一种陶瓷绝缘子的模拟装置。我们将传感器放置在模拟装置一侧,改变模拟器中的裂痕位置,通过传感器接收不同的回波信号,采集原始数据,从而对绝缘子裂缝实行位置检测。
为了提高检测准确率,我们还需探讨发射过程中复杂情况(复杂路径、其他障碍物等)对回波产生的干扰。实验的检测目标为模拟绝缘子检测装置中的裂缝,在毫米波传感器中,接收波到底是目标绝缘子裂缝的回波,还是为障碍干扰的杂波,在实验过程中一旦确定是目标绝缘子裂缝反射回来的波,才会进行下一步实验,例如利用MATLAB软件对数据进行图像分析。通常使用奈曼-皮尔逊准则,将虚警概率约束在指定常数范围内的情况下,精确的设定一个对应于虚警概率指标的门限,使检测概率达到最大[[1]]。CFAR检测就是致力于在实际干扰环境下提供可预知的检测和虚警概率的一组技术,又称为“自适应门限检测”[[2]]。
关键词:毫米波;绝缘子;在线监测技术
Abstract
Insulators, as the most commonly used and important electrical components in the power network, play the role of electrical insulation and mechanical support in the high voltage power transmission project. If the insulator fails in any way, it can cause power outages or blackouts, which can cause serious damage to the grid. Moreover, insulators are exposed to the air for a long time, and the external environment is complex and changeable, which can easily cause adverse effects on insulators. The good state of insulator is related to the safe operation of ultra-high voltage power network. Moreover, the power grid has a high demand for insulator reliability, and the demand is also huge. Therefore, the on-line monitoring of insulator crack is of great significance. At present, the traditional detection methods use unmanned aerial vehicles and workers" on-site inspection with instruments. These methods may have problems such as low safety factor, low accuracy and high cost. Therefore, this paper proposes to use millimeter wave technology to carry out real-time monitoring of insulators to ensure the reliable operation of insulators.
In this paper, we used a millimeter-wave sensor from TeraPark Technology (Nanjing) Co. Ltd. and their insulator emulation platform to achieve the goal of efficient crack detection of large-tonnage porcelain insulators in ultra-high voltage transmission engineering. Aiming at the problems of insulator automatic recognition, perception, positioning and detection, a new insulator on-line monitoring technology based on millimeter wave technology is validated. To emulate process of the development of micro cracks inside of insulator, the company introduced an emulation platform for the ease of experiment. We placed an millimeter wave sensor module facing to the emulation platform. By changing the position of the cracks, the sensor received different reflection signals and captured the raw data to fulfill the detection of the cracks.
In order to improve the detection accuracy, we also need to discuss the interference caused by complex conditions (complex path, other obstacles, etc.) in the transmitting process to the echo.Experimental testing goal to simulate the fracture of insulator detecting device, in millimeter wave sensor, receives the wave echo of crack and what is the target insulator for obstacles interfere with clutter, cracks in the process of experiment is once established goals insulator reflected wave, into the next phase of the experiment, such as image analysis using MATLAB software to data. Usually, the Naiman-Pearson criterion is used to restrict the false alarm probability within the specified constant range, and to accurately set a threshold corresponding to the false alarm probability index, so as to maximize the detection probability. CFAR detection is a group of technologies dedicated to providing predictable detection and false alarm probability under actual interference environment, also known as "adaptive threshold detection".
Keywords: millimeter wave, Insulator, On-line monitoring technology
目 录
摘 要 I
Abstract II
目 录 IV
第一章 引 言 1
1.1 研究背景及意义 1
1.2绝缘子检测技术的发展现状 1
1.2.1非电量检测法 1
1.2.2电量检测法 2
1.3本论文的组织结构 3
第二章 基于毫米波技术的绝缘子在线监测方案 4
2.1 毫米波雷达基本理论 4
2.1.1雷达基本知识 4
2.1.2 FMCW雷达工作原理 5
2.2 数据处理 5
2.2.1 傅里叶算法的基本理论 5
2.2.2毫米波雷达测距数据处理 8
2.3恒虚警概率检测 10
2.4 本章小结 11
第三章 基于Matlab的模拟绝缘子裂纹检测设计 11
3.1 实验平台介绍 12
3.1.1硬件平台 12
3.1.2软件平台 12
3.2不同因素对绝缘子裂纹检测的影响及实验流程 12
3.2.1测试区域及裂缝说明 12
3.2.2实验流程 13
3.3 本章小结 19
第四章 结束语 20
致谢 21
参考文献(References) 22
引 言
研究背景及意义
十四五期间,新基建特高压输电工程项目不断扩容,未来五年国内将有一大批特高压输变电工程相继开工建设。国内大吨位瓷绝缘子使用量已突破1000万片,需求量非常旺盛。特高压电网对大吨位瓷绝缘子的可靠性要求极高,特高压用瓷绝缘子技术条件要求投运后3年内,其年均劣化率不应大于十万分之五,使用寿命不低于40年。然而,国产大吨位瓷绝缘子受产品自身技术水平、制造工艺、运输安装和环境等多方面因素影响,新投运及挂网运行420KN及以上大吨位瓷绝缘子零值问题日渐频繁,劣化率连年升高,形势十分严峻。
面对特高压零值率上升问题,近年来电网公司加强了绝缘子的巡检力度,应用了一系列绝缘子检测的方法研究,如无人机带电红外检测、停电塔上人工测零等手段,取得一定效果,但受到环境影响,误判率高、安全风险高等多弊端,电网企业目前仍未走出绝缘子劣化概率过高的困境。本项目从治标治本角度出发,确保特高压工程长期安全运行,提出了新的解决思路:在绝缘子内部安装微型毫米波芯片,通过毫米波芯片实现绝缘子零值实时监测感知。
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