一种基于傅立叶算法的高精度测频方法  

A high-accuracy algorithm of frequency measurement based on Fourier algorithm

作　　者：叶芳[1] 焦彦军[1] 周丹[1] 王焯[1] 

机构地区：[1]华北电力大学电气工程系,河北保定071003

出　　处：《电力系统保护与控制》2012年第8期44-48,共5页Power System Protection and Control

摘　　要：针对传统软件测频方法存在的问题,提出了一种新的基于傅立叶算法的频率测量方法。首先仔细研究傅立叶修正系数测频法的误差情况,调整了修正系数的计算方法,提出傅立叶修正系数测频法的改进算法。然后根据信号频率偏移时傅立叶算法误差较大这一问题,提出根据信号近似频率进行插值,对插值后新序列进行傅立叶计算。为了提高含有谐波时的测频精度,对频率进行迭代计算,直至达到精度要求或迭代次数达到限值。最后对含谐波、不含谐波两种信号进行仿真计算,对比其频率计算误差。结果表明,该算法计算精度高,计算量小且实现了频率的高精度跟踪,可以满足电力系统实时性要求。Aiming at the existing problems of traditional frequency measurement method, this paper presents a new way ot trequency measurement based on Fourier algorithm. First, according to the error of the original Fourier frequency measurement algorithm, the amendatory coefficient is adjusted, an improved frequency measurement method based on Fourier correction coefficient is proposed. Then, because error of the Fourier algorithm is larger in the process of the frequency offset, interpolation algorithms have been proposed based on the approximate frequency of the signal to conduct Fourier calculation of the new set. In order to improve the measurement accuracy of signal frequency containing harmonic component, iterative calculation of the frequency is conducted until the algorithm precision meets the requirement or number of iterations reach the maximum. Finally, the errors of the calculation of frequency when there is harmonic component and isn＇t harmonic component in the signal are compared. The actual examples prove that the algorithm precision is effectively improved, the amount of calculation is significantly reduced, a high precision tracking system frequency is achieved, and it completely meets the requirement of real-time performance of the power system.

关 键 词：频率测量 傅氏算法 修正系数 牛顿插值 迭代 

分 类 号：TM935.1[电气工程—电力电子与电力传动]