基于Nuttall自卷积窗四谱线插值FFT的电力谐波分析方法  

Harmonic analysis of power system based on Nuttall self-convolution window four-spectrum-line interpolation FFT

作　　者：刘冬梅[1] 杨重良 张艳[1] 梅恒荣 LIU Dongmei;YANG Zhongliang;ZHANG Yan;MEI Hengrong(School of Electric Engineering and Automation,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽合肥230009

出　　处：《合肥工业大学学报（自然科学版）》2018年第1期12-17,共6页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(11105037;51577046);教育部科学技术研究重大资助项目(313018);安徽省科技计划重点资助项目(1301022036)

摘　　要：快速傅里叶变换(fast Fourier transform,FFT)在非同步采样条件下难以实现谐波的高精度检测,而加窗和插值算法可以提高谐波检测的准确度。文章在分析Nuttall自卷积窗频谱特性的基础上,提出了基于Nuttall自卷积窗四谱线插值FFT算法。该算法通过对加窗信号离散频点处幅值的分析,利用谐波频点附近的四根谱线进行加权运算,进一步提高谐波幅值、相位和频率检测的精度;采用多项式拟合的方式得到基于Nuttall自卷积窗四谱线插值修正公式。仿真数据表明,该算法具有较高的谐波检测精度,Nuttall自卷积窗有效地抑制了频谱泄露。Fast Fourier transform(FFT)in non-synchronous sampling condition is difficult to achieve high accuracy detection of harmonics,and window interpolation algorithm can improve the accuracy of harmonic detection.On the basis of the analysis of the spectrum characteristics of Nuttall self-convolution window,the four-spectrum-line interpolation FFT algorithm based on Nuttall self-convolution window is proposed.Based on the analysis of the amplitude of the discrete frequency points of the adding window signal and using weighted arithmetic of four spectral lines near the harmonic frequency point,the proposed algorithm can further improve the accuracy of harmonic amplitude,phase and frequency detection.And the polynomial fitting method is used to obtain the interpolation correction formula of the Nuttall self-convolution window four-spectrum-line.The simulation results show that the proposed algorithm is of higher harmonic detection accuracy,and the Nuttall self-convolution window can effectively suppress the spectrum leakage.

关 键 词：快速傅里叶变换(FFT) 非同步采样 Nuttall自卷积窗 四谱线插值 多项式拟合 

分 类 号：TM935.21[电气工程—电力电子与电力传动]