非稳态间谐波HHT变换检测方法研究

摘要

For the purpose of detecting a kind of inter-harmonic signals which frequency can vary with time, Hilbert-Huang Transform (HHT) was used to realize Empirical Mode Decomposition(EMD) and instantaneous frequency calculation for the unsteady state inter-harmonics in power distribution network.The experimental result showed that the method could not only effectively detect the amplitude and frequency of each frequency component power quality signal, but also accurately detect these signals starting and ending time.The shortcoming that time resolution and frequency resolution could not get optimal solution simultaneously in wavelet time frequency analysis is overcome by using this method.%采用希尔伯特—黄变换(HHT)实现配电网非稳态间谐波信号的经验模态(EMD)分解与瞬时频率求解,以实现频率随时间变化的间谐波信号的检测.试验结果表明:该方法不仅有效地检测出电能质量信号中各个频率成分的幅值、频率,而且准确检测出频率波动的起止时刻,克服了小波时频分析中时间分辨率和频率分辨率不能同时最优的缺点.