一种工程化检测次同步和超同步相量的方法

针对工程现场检测次(超)同步分量频谱分辨率稀疏的现状,文中总结现有算法工程应用的不适应性,提出快速傅里叶算法(fast fourier transformation,FFT)计算的工程化方法。首先结合低通滤波及FFT数据窗长度来消除频谱混叠的影响,再通过FFT计算结果的递减特性来消除基波频谱泄露对谐波计算的干扰,最后运用FFT修正算法消除栅栏效应的影响以准确计算次(超)同步振荡谐波的频率与幅值,同时根据FFT频谱幅值的极值出现次数来区分幅值突变的运行工况。以此为基础开发的监控装置能够满足电网次(超)同步振荡准确监控的功能要求。

An Engineering Detecting Method for Sub-synchronization and Super-synchronization Harmonic Phasors

In view of the fact that the spectral resolution of the sub (super) synchronous component of the engineering site is sparse,this paper summarizes the inadaptability of the existing algorithm engineering application and proposes an engineering method of FFT calculation.The effect of spectral aliasing is first eliminated by combining the low-pass filter and the FFT data window length,and then eliminating the interference of fundamental frequency spectrum leakage to harmonic calculation through the decreasing characteristic of FFT calculation results.Finally,using the FFT correction algorithm to eliminate the influence of the fence effect to accurately calculate the frequency and amplitude of sub (super) synchronous oscillation harmonics.Meanwhile,according to the FFT spectrum amplitude of the number of extreme occurrences to distinguish between the sudden changes in the operating conditions of the amplitude,as a basis for the development of monitoring devices to meet the grid sub (super) synchronous oscillation of the precise monitoring of functional requirements.