基于小波理论的电能质量分毕业论文.doc

基于小波理论的电能质量分析 摘要：本文以电力参数在线检测、分析系统研制为背景，针对系统所需做存储处理的畸变、故障信号数据规模过于庞大，从而使得系统分析、处理性能下降，存储成本上升的问题，讨论了利用基于正交离散小波变换的变换编码有损数据压缩思想的数据压缩方法。主要做了以下几方面的工作： 1.研究了小波分析的基本理论。滤波器组理论与离散小波变换有着天然的联系，正交小波多分辨分析理论明确地指出共扼镜像滤波器完全刻画了标准正交小波变换，而且快速离散小波变换可以通过级联这些共扼镜像滤波器运算来实现。 2.结合数字信号处理的多通道分析方法和滤波器组、小波分析的基本理论，提出了基于正交离散小波变换的电力系统畸变数据实时压缩方法。结果表明，在把信号信息损失控制在一个可以接受的范围的条件下，信号数据压缩能获得有意义的压缩率。这对于电力系统畸变、故障信号数据的存储、传输来讲，可以大幅节约成本，提高系统性能，增加经济效益。 关键词：电力系统，小波分析，滤波器组，数据压缩 Research on Application of Wavelet Theory in Electric Power Quality Analysis and Processing Abstract： Background of this paper is the development of Power Parameters Detection and Analysis Online System. Aiming at the problem of the bulk of disturbance or fault data system needs to save, which makes the system of bad performance and increases the cost of saving, a data compression way based on transform coding method of wavelet transform with little information lost is proposed. At the same time its use in data filtering is also considered. Main job done consists of three parts as following： First of all, basic wavelet theory is introduced. Discrete wavelet transform has tight relationship with filter banks in born. Multi-resolution analysis showed QMF banks are equivalent to quadrature wavelet transform. Fast wavelet transform could be achieved by cascading QMF banks operation. Finally, synthesizing multi-channel digital signal processing, filter banks and wavelet analysis theory, an electric power quality disturbance data compression realization has been proposed based on quadrature discrete wavelet transform. Simulation results show that with acceptable information lost within a limitation requirement remarkable compression ration could be obtained. This data compression way could benefit electric power quality disturbance data saving and transmission, improve supervision system’s performance and lower down the system cost. Key words：electric power system, wavelet analysis, filter banks, data compression目 录 第1章 绪论 1 1.1 小波变换的起源与发展 1 1