基于变分模态分解的电力系统泛频带振荡辨识方法

摘要

Oscillation is one of the most important stability problems of modern power system. In a power system, multiple types of oscillation crossing a broad-band may occur at a same time. In this paper, the mode identification for broad-band oscillation signal is proposed. First, the signal is decomposed to signals of different frequency bands by band pass filters. Then, the mode signals of the decomposed signals are extracted by using Variational Mode Decomposition(VMD)method. The mode parameters can be identified from the mode signals by Prony algorithm. The simulation and case study show that this method can distinguish and extract different kinds of oscillation modes of signals effectively and identify each mode's information accurately. It can accurately identify mode information from both oscillation signal and damped oscillation in ambient noise.%振荡问题已成为现代电网面临的重要问题之一,电力系统中多种类型的振荡可能同时出现且频段跨度极大.针对含泛频带振荡模态的信号,首先通过带通滤波器实现不同频段信号的分离,再利用有高噪声鲁棒性的变分模态分解(Variational Mode Decomposition, VMD)方法提取各个振荡模态信号,最后通过 Prony 算法实现对不同模态参数的辨识.仿真与实际算例分析表明,该方法能够对信号中不同类别振荡模态进行有效区分与提取,精确识别出每个模态的信息.无论针对已发生剧烈振荡的信号或是含有潜在振荡的类噪声信号,该方法均能有效地进行模态辨识.