一种基于小波包变换的电力谐波检测方法

由于非线性负载用电的不断增加，造成大量谐波返灌电网产生电能污染和计量不公等问题，然而传统的快速傅里叶变换（fast Fourier transform， FFT）检测方法由于自身技术的限制，难以满足目前谐波检测对精确性的要求。结合电力谐波特点，分析小波变换与傅里叶变换原理，提出了一种小波包与FFT相结合并采用加窗双谱线插值的电力谐波检测方法，研究了不同窗函数的特性，并且通过加入不同的窗函数来检测谐波，得出针对电力谐波检测最优的窗函数。仿真实验验证了该方法对谐波在时域和频域上都有很好的测量效果，为谐波电能表电力谐波检测方法及信号截取窗函数选取提供重要参考。

An Detection Method for Power Harmonic Based on Wavelet Packet Transform

As the nonlinear load increases, a large number of harmonic will back to fill the grid which may result in the power pollution and measuring inequality. However, the traditional fast Fourier transform （FFT） detection methods are difficult to meet the harmonic detection requirements for accuracy due to the limitation of their own technology. Combined with the characteristics of power harmonic form, this paper analyzed the principle of wavelet transform and Fourier transform, and put forward a kind method with double-spectrum-line and window function based on the wavelet packet combined with FFT. This paper mainly studied the characteristics of different window functions, and added them to get the optimal window function for power harmonic detection by comparison. The simulation results verify that the harmonic measurement method has a good measurement effect in time domain and frequency domain, and the simulation experiment provides a good reference for the detection method of power harmonic of harmonic watt-hour meter and the selection of window function of signal interception.