【作者】 胡广；

【导师】 张俊芳；

【作者基本信息】 南京理工大学 ， 电力系统及其自动化， 2010， 硕士

【摘要】 随着我国国民经济的飞速发展以及城市化建设步伐的加快,电力电缆获得了越来越广泛的应用。但在电力电缆的使用过程中,一旦发生故障,很难快速找到故障点的位置,如果不能及时排除故障并恢复供电,往往会造成巨大的经济损失。如何快速、准确的进行电力电缆故障测距,保障电网的正常运行,具有十分重要的意义。论文以数学形态学和小波分析为理论基础,对电力电缆故障测距方法、故障建模等方面进行了深入的研究与仿真,并设计了电力电缆故障测距系统。论文分析了电缆故障测距中普遍存在的反射波波头难以准确识别的问题,引入了数学形态学和小波分析理论,研究了它们在电力电缆故障测距中的应用,对行波测距方法进行了改进,将数学形态学和小波分析结合起来滤除行波信号中的噪声,在此基础上进行奇异性检测,找出行波到达的准确时刻。利用MATLAB建立了故障模型并进行了仿真,仿真结果表明改进的电力电缆故障测距方法解决了故障反射波波头的准确识别问题,提高了电力电缆故障测距的精度。论文设计了电力电缆故障测距系统。系统硬件主要包括以LPC2142作为主CPU的高速数据采集电路,该电路使用高速A／D转换芯片和串行通讯接口实现数据的采集及传输,并实现数据的显示功能。系统软件主要分为2部分：一是用C++语言编写了下位机程序,主要完成系统初始化、信号采集、数据显示及传输等工作；二是用C++语言和MATLAB语言编写了上位机软件,完成采样数据的分析处理以及电缆故障距离的计算。论文最后对电力电缆故障测距系统进行了实验测试,结果表明该系统满足电力电缆故障测距的要求。更多还原

【Abstract】 With the rapid development of economy and acceleration of urbanization, power cable is used widely. But if the power cable goes wrong during use, it is difficult to locate the fault quickly. If can’t eliminate the cable fault and restore power supply in time, huge economical loss will be made. For the normal operation of power grids, it is necessary to locate the cable fault rapidly and accurately. Under the mathematical morphology and wavelet theory, this article makes a thorough study of power cable fault location method, fault modeling and simulation, and designs a power cable fault location system.This article analyzes the initial time of reflected wave in power cable fault location. This article also introduces the basic concepts of mathematical morphology and wavelet, and studies the application of them in fault location of power cable, which mainly includes noise reduction and singularity detection. Then established fault model with MATLAB, simulation result shows that combining mathematical morphology and wavelet transform can solve the problem of the initial time of reflected wave, and improve the accuracy of power cable fault location.Then the fault location system of power cable is designed in this article. The hardware of system mainly contains high-speed data sampling circuit which contains high speed A/D chip for data acquisition and serial ports for data transmission, and display sampling data. The software of system mainly contains 2 parts:one is the program of lower computers with C++ language, which mainly used to initialize the system, sample data, display and transfer data; the other is PC software with C++language and MATLAB language, which mainly used to analyze and handle sampling data, and calculate power cable fault position.At last, the performance of power cable fault location system is tested in this article, The test result indicates that the system meets the requirements of power cable fault location.更多还原