一种基于正序分量的改进傅氏测频算法

An Improved Fourier Algorithm for Frequency Measurement Based on Positive Sequence Component

从系统中性点漂移影响和特定谐波在正序分量中表现特性两个方面,分析基于正序分量的傅氏测频算法的改进机理.通过建立信号和采样模型以及MATLAB工具仿真,验证基于正序分量数据源计算的傅氏测频算法的改进效果.该算法降低了傅氏计算窗口数据初始相位对测频精度的影响,减小了谐波分量对傅氏测频算法精度的影响,也减小了计算输出频率与系统实际频率偏差对傅氏测频算法结果的影响.该算法适合定频采样的保护装置,且计算量不大,特别是本来需要计算序分量的保护装置.

The improvement mechanisms of Fourier frequency measurement algorithm based on positive sequence component was examined in terms of the influences of system neutral point voltage drifting and the performance characteristic of specific harmonics in positive sequence component.By building signals and sampling models,and by use of MATLAB simulations,Fourier frequency measurement algorithm based on positive sequence component was proved effective.This algorithm is able to reduce the influences of Fourier calculation window data initial phase on frequency measurement precision,and reduce the influences of harmonic component on the accuracy of Fourier frequency measurement algorithm,and reduce the influences of deviation between calculation frequency and actual system frequency on Fourier frequency measurement results.This algorithm is suitable for protection units using fixed sampling frequency,especially for those that need calculating sequence components due to small amount of calculation.