基于振荡分量时频特性的次同步振荡早期预警

Early warning of sub-synchronous oscillation based on time-frequency characteristics of oscillatory components

针对目前次同步振荡辨识方法是在振荡已经较大程度发生时才能辨识出来的缺陷,提出了一种次同步振荡危险分量的早期辨识方法。利用EMD重组滤波的方法提取出在次同步振荡范围内的分量,将其重组后作为分析信号,对信号做希尔伯特黄变换得到各振荡分量的振荡参数和时频变化关系,根据振荡分量频率与特征频率的走势关系和阻尼比,对振荡分量的危险性做出早期判断。用理想信号验证了所提方法对振荡参数辨识的精度,并以哈密地区次同步振荡的实际录波数据验证了此方法能够对次同步振荡做出早期预警。

Aiming at the defect that the identification methods of sub-synchronous oscillation can only be identified when the oscillation has occurred to a large extent,an early identification method of sub-synchronous oscillation dangerous components is proposed in this paper.The components in the sub-synchronous oscillation range are extracted by EMD recombination filtering method,and the components are recombined as analysis signals.The relationship between oscillation parameters of each oscillation component and time-frequency variation are obtained by Hilbert-Huang transform.According to the trend relationship and damping ratio of the oscillation component frequency and characteristic frequency,the risk of the oscillation component is early judged.The accuracy of identification of oscillation parameters is verified by ideal signals,and the early warning of sub-synchronous oscillation is verified by the actual recorded data of sub-synchronous oscillation in Hami area.