基于局部均值分解算法的电力系统低频振荡研究  

Research on Low Frequency Oscillation of Power System Based on LMD

作　　者：谭积成 孙晨祺 何首贤[3] 

机构地区：[1]沈阳市和平区城市建设管理局,沈阳110000 [2]辽宁工程技术大学电气与控制工程学院,辽宁葫芦岛125105 [3]大连海洋大学应用技术学院,辽宁大连116300

出　　处：《船电技术》2016年第1期57-61,共5页Marine Electric & Electronic Engineering

摘　　要：本文针对在研究电力系统低频振荡时易出现负频率和端点效应较严重的问题,结合局部均值分解局部均值分解(LMD),提出了基于LMD的电力系统低频振荡研究新方法。该方法可将复杂的振荡模态分解为若干振荡模态之和,每个振荡模态由幅值函数和调频函数之积组成。LMD采用了滑动平均法拟合幅值函数,避免了过包络、欠包络现象,端点效应较小;通过对调频函数求导获得各个振荡模态的瞬时频率都是正的、具有物理意义的时变频率。幅值函数反映了振荡的阻尼特性,频率函数反映了振荡的时变特性,研究瞬时幅值函数和瞬时频率函数可以有效获取振荡模态的暂态信息和振荡特性。Aimed at more serious problem of negative frequencies and the end effect in the analysis of power system low frequency oscillation for HHT, and combined with the local mean decomposition, this paper presents a new analysis of the LMD-based power system low frequency oscillation. The method separates complex oscillation mode into certain number of oscillation modes, each oscillation mode of which is composed of amplitude function and FM function integrated. LMD uses sliding average method to fit the amplitude function, avoiding over and low envelope, due to the phenomenon of the envelope, and having small the end effect. By the derivation of the FM function, the instantaneous frequency of the oscillation modes obtained is positive, and has the physical meaning of the time-varying frequency. That means, the amplitude function reflects the oscillation damping characteristics ,and the frequency function reflects the time-varying characteristics of oscillation.

关 键 词：局部均值分解 低频振荡 阻尼特性 电力系统 希尔伯特-黄变换 

分 类 号：TM712[电气工程—电力系统及自动化]