基于FFT的电网谐波检测误差分析与研究姜钰梁.pdf

研 究 与 设 计 基于FFT 的电网谐波检测误差分析与研究 姜钰梁，谭智力，董彦敏 （中国地质大学（武汉）机械与电子信息学院，湖北武汉430074） 摘要：谐波检测对谐波补偿装置的研究与设计有着重要的意义，而在谐波检测的各种算法中基于傅里叶变换的谐波检 测算法应用较为广泛。但标准FFT 谐波检测算法要求整周期的同步采样，否则就会产生频谱泄漏和栅栏效应从而使谐 波检测产生较大的误差。在具体分析了产生频谱泄漏和栅栏效应的基础上，对非同步采样时的标准FFT 谐波幅值检测 算法中所纯在的误差进行了研究与分析，提出了加窗插值FFT 算法谐波参数检测算法。推导了基于Blackman 窗的插 值FFT 算法的幅值、相位、频率的计算表达式，并利用MATLAB 对其仿真得出相应的结论。 FFT 关键词：窗函数；谐波分析； ；频谱泄漏 TM 464 A 1002- 087 X(2012)09- 1383- 03 中图分类号： 文献标识码： 文章编号： Accuracy analysis of harmonic detection methods in gird based on FFT JIANG Yu-liang, TAN Zhi-li, DONG Yan-min School of Mechanical and Electronic Information, China University of Geosciences, Wuhan Hubei 430074, China （ ） Abstract: Harmonic detection has an important significance to the research and design of harmonic compensation devices, but in all kinds of harmonic detection algorithms, harmonic detection algorithm based on Fourier transformation is widely used. However, the standard FFT harmonic detection algorithm requires the whole cycle of synchronous sampling, otherwise it will produce spectrum leakage and fences effect so that harmonic detection causes greater errors. The spectrum leakage and fences effect was analyzed in this paper, the existence of the errors in standard FFT harmonic amplitude detection algorithm of asynchronous sampling were researched and analyzed, the add window interpolation FFT algorithm harmonic parameters detection algorithm was proposed. The related formulas based on amplitude, phase and frequency of Blackman window interpolation FFT algorithm amplitude