矩形窗三点插值傅里叶变换高精度频率估计方法  

Rectangular window three-point interpolation Fourier transform high-precision frequency estimation method

作　　者：熊德智 肖宇 胡军华 黄瑞 温和 温乐鹏[2,3] XIONG Dezhi;XIAO Yu;HU Junhua;HUANG Rui;WEN He;WEN Lepeng(State Grid Hunan Electric Power Corporation Limited,Changsha 410004,China;Hunan Province Key Laboratory of Intelligent Electrical Measurement and Application Technology,Changsha 410004,China;College of Electrical and Information Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]国网湖南省电力有限公司,湖南长沙410004 [2]智能电气量测与应用技术湖南省重点实验室,湖南长沙410004 [3]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《中国测试》2023年第9期57-62,共6页China Measurement & Test

摘　　要：针对电力系统信号频率估计的高准确性要求,该文提出一种基于矩形窗的三点复频域插值频率估计方法。所提出的方法首先采用矩形窗对信号加权处理,然后进行离散傅里叶变换,最后选择离散频谱中幅度最大的三根谱线进行复频域插值,得到频率估计结果。该方法同时考虑离散频谱中的正、负频谱,消除短程和长程频谱泄漏对频率估计误差的影响。采用主瓣最窄的矩形窗进行加窗,能最大程度地减少白噪声对频率估计误差的影响。仿真和实验结果表明:在不同周期和噪声强度情况下,所提出的方法均可以实现对信号频率的准确估计。在与已有的加窗插值傅里叶变换方法相比,该文所提出的插值算法抗噪性更好、频率估计误差更小,适用于对电力系统信号频率的准确估计。Aiming at the high accuracy requirement of power system signal frequency estimation,this paper proposes a three-point complex frequency domain interpolation frequency estimation method based on rectangular window.The proposed method first uses a rectangular window to weight the signal,then performs discrete Fourier transform,and finally selects the three spectral lines with the largest amplitude in the discrete spectrum for complex frequency domain interpolation to obtain the frequency estimation result.This method simultaneously considers the positive and negative spectrum in the discrete spectrum to eliminate the influence of short-range and long-range spectral leakage on the frequency estimation error.The rectangular window with the narrowest main lobe is used for windowing,which can minimize the influence of white noise on the frequency estimation error.Simulation and experimental results show that the proposed method can achieve accurate estimation of signal frequency under different periods and noise intensities.Compared with the existing Fourier transform method of windowed interpolation,the interpolation algorithm proposed in this paper has better anti-noise and smaller frequency estimation error.So it is suitable for accurate estimation of power system signal frequency.

关 键 词：频率估计 傅里叶变换 频谱插值 窗函数 

分 类 号：TM933[电气工程—电力电子与电力传动]