应用傅氏算法的几个问题讨论

Discussion on the Fourier algorithm application

傅氏算法在数字保护中得到了广泛的应用,但关于傅氏算法中余弦正弦系数a,b是否为信号相量的实部和虚部,作者一直感到困惑。通过分析近年发表的相关傅氏算法的文献,提出对几个问题的质疑,结合实际的工程实例和信号的物理意义,认为信号的虚部是-b即相量用In=an-jbn表示,才能正确计算出阻抗、负序分量等。

Fourier algorithm has been largely applied to digital protection.However,it is puzzled whether coefficients a and b are real or image parts of the phasor. After analyzing the relevant documents published in recent years, some problems are put forward in this paper. It is concluded that the phasor can be represented by the form of a-jb,and thus the impedance and negative sequence component can be calculated correctly.