基于置零点窗函数的电力谐波FFT分析方法  

FFT analysis method of power harmonics based on placing-zeros window function

作　　者：李博 尹家悦 李波 肖勇 曹敏 LI Bo;YIN Jiayue;LI Bo;XIAO Yong;AO Min(Electric Power Research Institute,Yunnan Power Grid Co.,Ltd.,Kunming 650217,China;Yunnan Key Laboratory of Green Energy and Digital Power Measurement and Control&Protection,Kunming 650217,China;Electric Power Research Institute,CSG,Guangzhou 510663,China;Key Laboratory of Guangdong Power Grid Intelligent Measurement and Advanced Measurement Enterprises,Guangzhou 510663,China)

机构地区：[1]云南电网有限责任公司电力科学研究院,昆明650217 [2]云南省绿色能源与数字电力量测及控保重点实验室,昆明650217 [3]南方电网科学研究院有限责任公司,广州510663 [4]广东省电网智能量测与先进计量企业重点实验室,广州510663

出　　处：《电测与仪表》2024年第9期197-203,共7页Electrical Measurement & Instrumentation

基　　金：国家重点研发计划课题(2016YFF0201202);中国南方电网有限责任公司科技项目(ZBKJXM20190042)。

摘　　要：基于快速傅里叶变换(fast Fourier transform,FFT)的电力谐波算法,受到栅栏效应与非同步采样频谱泄露的影响,测量精度有待进一步提高。加窗和插值修正算法是改善FFT谐波参数测量准确度的有效方法。文章在置零点余弦窗的旁瓣特性和多项拟合插值算法基础上,提出置零点余弦窗FFT的电力谐波分析方法。根据谐波特点设计不同的余弦窗函数,由于窗函数的设计具有灵活性,针对某一种窗函数的插值算法不再适用,因此给出了更具一般性的双谱线和三谱线插值修正公式,为基于FFT的谐波分析提供新的方法。对旁瓣特性以及各次谐波的频率、幅度、相位的测量算法进行仿真分析,通过与经典的Hanning窗、Nuttal窗、Rife-Vincent窗的比较验证了所提方法具有更高的谐波参数分析精度。Due to the picket fence effect and the problem of spectrum leakage in the case of asynchronous sampling,the measurement accuracy of power harmonic analysis based on fast Fourier transform(FFT) needs to be further improved.Windowing and interpolation algorithms are effective methods to improve the measurement accuracy of FFT harmonic parameters.Based on the sidelobe characteristics of the placing-zeros cosine window and polynomial interpolation algorithms,the power harmonic analysis method of the placing-zeros cosine window FFT is proposed in this paper.Different cosine window functions are designed according to the characteristics of harmonics.Due to the flexibility of window function design,the interpolation algorithm for a certain window function is no longer applicable,so more general revised formulas for bispectral and trispectral interpolation are given,which provides a new method for FFT-based harmonic analysis.The sidelobe characteristics and the measurement algorithms of the frequency,amplitude and phase of each harmonic are simulated and analyzed.The comparison with the classic Hanning window,Nuttal window,and Rife-Vincent window verifies that the methods has higher analysis accuracy of harmonics parameter.

关 键 词：置零点余弦窗 插值 谐波分析 快速傅里叶变换 

分 类 号：TM933[电气工程—电力电子与电力传动]