滤除衰减直流分量的改进傅氏算法探讨

A improved fourier algorithm for decaying DC component filtration

傅里叶变换在电力系统继电保护中已广泛应用,但电力系统发生故障时,其中的衰减直流分量会影响测量的精度。提出的对交流采样序列值进行修正的改进傅氏算法,保留了全波傅氏算法的滤波功能,又增加了对衰减直流分量的过滤作用,能有效抑制非周期直流衰减分量的影响。通过算例仿真,验证了方法的准确性。

Fourier transform has been widely used in power system protection, when power system failure; the decaying DC components will affect the accuracy of the measurement. An improved Fourier algorithm of AC sampling sequence correction is proposed , which not only retains the advantage of full-wave Fourier filtering algorithm, but also increases the attenuation of the DC component of the filter and effectively suppresses non-periodic DC attenuation com- ponent. Through numerical simulation, to verify the accuracy of the method.