基于最大相关性的小波谐波检测方法

Research on harmonic detection methods of wavelet transform with max-correlation base on max-correlation

谐波的存在严重影响电网中电能的质量,保证电力系统的安全运行,首先要对谐波进行准确的检测和分析,剖析电网中的谐波成分。傅里叶变换能够分析谐波中稳态成分,却无法分析电力谐波中广泛存在的暂态及突变信号。小波变换的时频分析方法应用于谐波分析当中,弥补了傅里叶变换的这一缺陷。本文通过Matlab仿真,采用最大相关性的方法选取小波基,并用小波变换实现对电力系统中暂态信号的分析,将小波变换与傅里叶变换的分析方法进行比较,验证了基于小波变换的谐波检测方法的有效性。

The existence of harmonics affects the quality of power seriously. In order to ensure the op- eration of power system securely, the accurate detection and analysis for the harmonic components is carried out. Fourier transform can be used to analyze the steady-state composition of harmonic, but it can not be used to analyze the transient or abrupt signals. The method of time-frequency analysis based on wavelet transform will overcome the defects of Fourier transform. From the Matlab simula- tion, the wavelet base is selected with max-correlation method, the analysis of transient signals in power system is realized by using wavelet transform, and a comparison between Fourier transform method and wavelet transform method is carrid out. Finally, the effectiveness of this method is veri- fied.