摘要
小波包变换 ( WPT)建立在二进小波变换的基础上 ,理论上可以实现信号频带的均匀划分 ,可以更好地提取信号的时频特征 ,但是小波包变换得到的频带不是按频率大小连续排列 ,给实际的信号分析带来混乱。本文利用离散傅立叶变换原理分析了向下采样对信号的影响 ,分析了小波包变换得到的频带的特点 ,在此基础上 ,分析 WPT频带划分的特点 ,通过仿真验证 ,本文得到的结论是正确的 。
Wavelet packet transform(WPT)is established based on binary Discrete WT.It can decompose the spectrum of a signal into uniform sub bands,thus improve the accuracy of harmonic detection.But the frequency sub bands of WPT are not arranged according the value of frequency, thus gives forth to disarray in time frequency analysis.This paper analyzes the down sample effect on harmonics using Discrete Fourier Transform(DFT),analyzes the frequency division character of WPT,Simulations validate the results obtained in this paper,Therefore,It presents good bases for the wide use of WPT in power system.
出处
《电力系统及其自动化学报》
CSCD
2003年第2期5-8,共4页
Proceedings of the CSU-EPSA
