基于Meyer小波和FFT的电网间谐波检测

摘要

针对快速傅里叶法对间谐波的检测存在频谱泄露和栅栏现象,提出了利用FFT和小波变换综合的间谐波检测法.该方法由FFT算法得到各频谱的频率,根据得到的频率确定多分辨率的分解层数和频段范围.最后运用无限可导、双正交性和无频谱混叠现象的Meyer小波对信号进行分解和重构,得到无频谱泄露和栅栏现象的各间谐波分量.该分析法得到的仿真结果和目前常用的db3小波仿真结果相比更具有效性,可以准确地提取基频分量和各次间谐波分量,并实时跟踪间谐波的变化,达到了检测间谐波的目的.%As the detection of inter-harmonic based on the traditional fast Fourier transform algorithm exists spectrum leakage and fence phenomenon, an inter-harmonics detection method is presented, which comprehensively applies FFT and wavelet analysis.The frequency of the spectrum is obtained by the FFT firstly, and then the multi-resolution decomposition level and frequency range are determined by using the special frequency.Finally, Meyer wavelet with infinite differentiability, biorthogonal and non-overlapping frequency bands is applied to do the signal's decomposition and reconstruction, thus to obtain the interharmonic component of non-spectrum leakage and the fence phenomenon.It shows that the complex inter-harmonic detection algorithm can extract the fundamental frequency component and inter-harmonic component accurately and real-time track the changes of the inter-harmonic.It is more effective than the common db3 wavelet.