摘要
分析闪变的关键是提取电压闪变信号的包络线。将一种新的非平稳信号处理方法,即局部均值分解(LMD)方法应用于电压闪变包络线的提取。利用LMD方法对单频闪变、多频闪变、时变闪变信号等典型闪变信号进行仿真分析,证明了该方法提取闪变包络线的有效性。结果表明,LMD方法在提取闪变频率15 Hz及以下的包络线时,检测误差较小,尤其是在闪变低频段的检测准确度更高,弥补了平方检测法低频段检测误差较大的缺陷。此外,可以较准确地检测时变信号扰动发生和恢复的时刻。对载波畸变时的闪变信号仿真分析表明,无需滤波环节,提取不含谐波成份的闪变包络线,体现了LMD方法在提取闪变包络线中的优势。
Flicker envelope tracking is the key of analyzing voltage flicker signal. A novel non-stationary signal processing method, i. e. , local mean decomposition （LMD） method is applied in the detection of the envelope of voltage flicker. The typical flicker signals, such as one or multi-frequencies and frequency time-varying flicker signal are selected and analyzed by LMD method. Simulation results indicate that this method is effective in the detection of the en- velope of voltage flicker signal. Results of one or multi-frequencies flicker signal simulation show that, when flicker frequency is less than 15 Hz , the error of LMD method is quite tiny. The detection precision of LMD method is higher, especially in the scope of low frequencies of flicker and this method makes up for the disadvantage of square demodulation. Further more, results of frequency time-varying flicker signal simulation show that, the occurrence and recover time of voltage flicker signal can be accurately detected by LMD method. The analysis and simulation of the flicker signal with carrier distortion demonstrate flicker envelope containing no harmonic component could be detected without filter by LMD method. The advantage of LMD method is showed in the detection of the envelope of voltage flicker signal.
出处
《华北电力大学学报（自然科学版）》
CAS
北大核心
2014年第3期10-16,共7页
Journal of North China Electric Power University：Natural Science Edition
关键词
电能质量
电压闪变
局部均值分解
包络线检测
载波畸变
power quality
voltage flicker
local mean decomposition
envelope tracking
carrier distortion
