基于小波分析的电能质量谐波仿真分析--毕业论文.docVIP

本科毕业论文(设计) 题 目： 基于小波分析的电能质量谐波仿真分析 学 院： 自动化工程学院 专 业： 级自动化 班 姓 名： 指导教师： 2012年 6 月 2 日 Electric Power Quality Harmonic Simulation Analysis Based On The Wavelet Analysis 摘 要 近几年来,随着电网中元件复杂、结构繁琐、大量增加非线性负载、广泛应用的敏感电子设备等, 使得电能质量问题日趋严重，造成三相电压的不对称性、谐波污染，以及电压波动和闪变，谐波问题成为干扰电能质量的主要因素。 本文在提出了目前电力系统中谐波问题的出现和危害的基础上，学习了小波变换理论，与窗口傅里叶变换不同的是，小波变换的时间－频率窗口不是固定不变的，克服了快速傅里叶变换和短时傅里叶变换的缺点，特别适合于突变信号和不平稳信号的分析，适合于提取电力信号中的暂态信号 关键词 电力系统 谐波 小波变换 Abstract The power system harmonic pollution is serious, because the harm of harmonic have seriously affected on the normal operation of the power system.In order to maintain the normal operation of the power system’s security, analysis and measurement harmonic is imperative. The harmonic detection is the foundation of the harmonic treatment, it is also one of the active power filter’s key technicals. Because of the wavelet transform has high precision, not only can the steady-state signal analysis, can also analysis the time-varying transient signal advantage, therefore has become the new research direction of power system harmonic detection. And window Fourier transform is different, the wavelet transformation of the time-frequency window is not fixed, overcoming the fast Fourier transform and short-time Fourier transform faults, particularly suitable for mutations signal and not stationary signal analysis, can grasp the signal local details, this also is wavelet transform and Fourier transform the biggest advantage compared. So wavelet transform is very suitable for extraction of electric power signal transient signal, for complex signal and time-varying signal also can more accurately its information extraction. Key words electric power system harmonic wavelet wavelet transform 目 录 前 言 1 第一章 绪论 2 1.1 电能质量中谐波问题 2 1.1.1谐波问题的提出及危害 2 1.1.2 谐波问题的基本原