频域紧支撑正交小波及其在暂态保护中应用

The Orthogonal Wavelet with Compact Support in Frequency Domain and Its Application on Transient Protection

小波分析作为时频分析工具已经越来越广泛地应用于电力系统的各个领域 ,如何选择和构造最适合用户需要的小波具有重要意义。从信号的时频分析角度 ,频域紧支撑小波比时域紧支撑小波具有更好的分频效果 ,然而其时域的衰减性较差。介绍了构造频域紧支撑小波的一般方法 ,分析了频域紧支撑小波的性质 ,并在Meyer小波基础上提出了构造理想分频效果并且具有任意阶衰减及满足各种相频响应需要的频域紧支撑正交小波。模拟暂态信号的小波分析结果表明 ,该小波的分频效果和计算的有效性是令人满意的。

Wavelet analysis, as a time frequency analysis tool, has been widely used in many fields of electric power system. To select and construct the best wavelet for user is of important significance. From the time frequency analysis of signal, wavelet with compact support in frequency domain has better frequency characteristics than that in time domain, however it attenuates slowly in time domain. The general method of constructing a wavelet is introduced and the characteristics of wavelet with compact support in frequency domain are analyzed. Based on Meyer wavelets, the construction of wavelet with compact support in frequency domain is proposed, which has better frequency characteristics and any decay rate to meet the need of different phase? frequency response. The wavelet analysis result of simulative transient signals shows that the wavelet frequency partition and the calculation effectiveness are satisfying.