单相接地故障论文：基于FFT的配电网单相接地故障定位研究与实现.doc

单相接地故障论文：基于fft的配电网单相接地故障定位研究与实现【中文摘要】我国配电网大多采用的是中性点非有效接地方式,即小电流接地系统。配电网结构复杂,发生的故障大多数都是单相接地故障。因此,配电网单相接地故障能否快速准确定位,对保障电力线路正常输配电,保证整个电力系统安全、稳定、经济运行有着十分深远的意义。近年来,低频交流信号注入法在配电网单相接地故障定位中得到了有效而且较广泛的应用。由于导线分布电容的影响,低频交流信号注入法采用60hz注入信号代替“s”信号注入法的220hz注入信号。低频交流信号法采用二分法沿线路查找故障,探测器显示当前位置的实时电流波形,由于户外环境等因素,实时波形有时候难以判断当前位置的电流是分布电容电流还是故障电流。本文对探测器进行系统设计,硬件部分包括滤波放大电路,控制部分和显示部分,用protel绘制电路板,主要芯片选择8051f310和uaf42来完成;软件部分设计包括单片机模数转换部分,定时计数部分,中断及频谱分析部分,用keilc来完成程序的编译工作。本文用fft算法对探测到的电流信号进行频谱分析,比对工频信号和注入信号含量,通过显示两信号的能量分布来判断当前位置是否是故障点。【英文摘要】the distribution networks mostly adopt neuter point not- valid grounding in china, which is called the small current grounding system. the fault in distribution networks mostly is single-phase grounding fault because of its complex structure. the fast and accurate location that the single grounding fault, not only to the repair wire and promise dependable power supply, and circulate to the safe stability and economy that promises the whole electric power system to all have a very important function.the low frequency ac signal injection method applies effectively and widespread in distribution network single phase-to-grounding fault location. traditional“s”injection method with 220hz injected frequency is affected by the wires distributed capacitance, so low frequency method adopts 60hz instead of 220hz. the low frequency method uses dichotomy along the route to detect the fault, and its detector displays the real-time current waveform of the current position. due to the outdoor environment factors, its difficult to judge the present current distributed capacitance current or the fault current through the real-time waveform. the signal detector is designed systematically in the paper. the hardware part includes filter and amplification circuit, control section and display section, using protel to draw boards with single chip 8051f310 and the filter uaf42. the software part includes the design of microcontroller a/d part, timing counter part, disruptions and spectrum analysis, with keil c to complete part program compiles work.a fft algorithm is used to analyze the detected current signals spectrum in the paper. after compared the energy content with the power signal and the injected signal, the fault point can be judged by showing the two signalsenergy content.【关键词】单相接地故障 低频信号注入 探测器 频谱分析【英文关键词】single phase-to ground fault low frequency ac signal injection detector spectrum analysis【目录】基于fft的配电网单相接地故障定位研究与实现摘要5-6abstract6第1章 绪论9-131.1 配电网单相接地故障的特点9-101.2 配电网单相接地故障定位方法的研究现状10-111.2.1 被动式定位方法101.2.2 主动式定位方法10-111.3 配电网单相接地故障定位的意义11-121.4 本文的主要内容121.5 本文的章节安排12-13第2章 低频交流信号注入法13-202.1 “s”信号注入法13-152.1.1 “s”信号注入法的产生和特点13-142.1.2 信号注入法原理142.1.3 注入信号选择14-152.2 低频交流信号注入法原理及应用15-182.2.1 配电线路导线分布电容15-162.2.2 配电线路导线分布电感16-172.2.3 低频交流信号法注入信号特征的确定17-182.3 低频交流信号注入法的优势18-192.4 本章小结19-20第3章 信号处理理论应用20-303.1 采样定理20-213.2 快速傅里叶变换算法21-233.2.1 离散傅里叶变换算法213.2.2 快速傅里叶变换21-233.3 频谱分析23-253.3.1 频率分辨率23-243.3.2 频谱分析步骤243.3.3 快速傅里叶变换算法的物理意义24-253.4 仿真分析25-293.4.1 fft 技术应用的目标253.4.2 频谱分析仿真25-293.4.3 结论293.5 本章小结29-30第4章 信号探测器硬件设计30-414.1 信号探测器原理及应用方法30-314.1.1 交流信号探测器原理304.1.2 交流探测器的应用30-314.2 信号探测器硬件设计实现31-394.2.1 信号处理模块32-354.2.2 滤波器35-384.2.3 放大电路384.2.4 显示模块38-394.3 探测器硬件电路绘制39-404.4 本章小结40-41第5章 系统软件设计41-485.1 系统总体设计思路41-425.1.1 软件编写环境415.1.2 软件程