一种数字化变电站频率测量算法

针对目前数字化变电站由于频率变化导致FFT计算频率出现泄漏的情况,提出了一种简单实用的测频方法.该法经过固定频率的坐标变换,将待提取的信号变换为低频信号,其他无用的信号为高频信号,利用设计好的简单的3阶低通Butterworth滤波器提取出该低频信号,并经过简单计算可以得到该系统内与固定频率的差值,从而得到了真实的频率.理论推导和仿真实验表明:该系统稳定性好,计算精度高.

A Frequency-Measuring Algorithm in Digital Substation

In view of the FFT calculation frequency leakage situation of present digital substation due to frequency variation, this paper introduces a simple and functional frequency-measuring algorithm.After the coordinate transformation of fixed frequency , low frequency signals are extracted , and other unwanted signals are high frequency signals .This paper designs simple three order low-pass Butterworth filter to extract the low-frequency signals , by which the frequency difference between the frequency of this system and the fixed frequency can be achieved through simple calculation and then the real frequency is obtained .Theoretical derivation and simulation experiments show that the system has good stability and high calculation precision .