基于小波变换Mallat算法的电网谐波检测方法

A harmonic detection method for power network based on wavelet transform Mallat algorithm

针对传统的傅里叶变换方法在分析非平稳运行电网的电量信号时误差较大的问题,提出了一种基于小波变换Mallat算法的电网谐波检测方法。该方法根据不同的分辨率将电量信号分解到不同的子频段,然后分别对子频段进行多次重构,得到原始信号的基波,最后将采样得到的原始信号与重构的基波信号相减,得到谐波信号。Matlab仿真结果表明,该方法能够有效地将电量信号中的基波与谐波成分分离,谐波检测精确度较高。

For the problem that traditional Fourier transform method caused big errors when analyzing power signals of power network under unstable running condition,a harmonic detection method for power network was proposed based on wavelet transform Mallat algorithm.Firstly,power signals are separated into different sub frequency bands according to resolutions.Then each sub frequency band is reconstructed to get fundamental wave of original signal.Finally,the reconstructed signal of fundamental wave is subtracted from the sampled original signal so as to get harmonic signal.The Matlab simulation results show that the method can separate harmonic signal from fundamental wave of power signal with high precision of harmonic detection.