摘要
小波变换作为一种新的时频分析工具已经得到了广泛的应用，但对信号进行小波变换时各尺度之间的频域‘混叠’现象往往影响分析的效果，即使具有理想分频行为的 Ｓｈａｎｎｏｎ 小波也会产生‘ Ｇｉｂｂｓ’现象。本文利用哈明窗函数构造了一个新的小波函数，此小波不仅在频域具有近似 Ｓｈａｎｎｏｎ 小波的理想划分特性，而且时域局部性明显优于后者进而有效的克服了‘ Ｇｉｂｂｓ’现象。文中用新小波分析了仿真得到的电容投切产生的暂态信号，结果表明新小波在暂态信号分析方面具有独特的优越性。
Wavelet transform,as a new time frequency analytical tool,has been widely used.However,frequency domain ‘aliasing’ at different scale offen affects the analytical result using wavelet transform,even Shannon wavelet with ideal frequency decomposition yields ‘Gibbs’ phenomenon.This paper constructs a new wavelet function using Hamming window.The new wavelet function has the ideal division characteristic in frequency domain which is similar to Shannon wavelet and linear phase.Moreover,the time domain characteristic of the new wavelet is superior to the latter,so it can overcome the ‘Gibbs’ phenomenon effectively.The simulated transient signal by switching capacitor is analyzed using the new wavelet function,the result shows that the new wavelet function has unique advantage to analyze the transient signal.
出处
《电力系统及其自动化学报》
CSCD
1999年第3期74-79,共6页
Proceedings of the CSU-EPSA
关键词
电力系统
时频分析
暂态信号
小波构造
故障
power system, time frequency analysis, transient signal, wavelet construction
