基于改进Hilbert-Huang变换的暂态电能质量扰动定位方法

Transient power quality disturbances location method using improved Hilbert-Huang transform

针对经验模态分解过程中容易过度筛选的问题,该文改进了筛选停止准则,对Hilbert-Huang变换进行了改进,并将改进Hilbert-Huang变换方法应用于暂态电能质量扰动信号的检测及时频分析中。该方法在对暂态电能质量扰动信号进行经验模态分解得到固有模态函数后,再进行希尔伯特变换,可以定量、准确地刻画扰动信号的时间、频率和幅值信息。实验结果表明:该方法可以实时准确检测扰动的起止时刻、持续时间和扰动幅度,适用于暂态电能质量扰动的监测系统。

Aiming at the reduction of excessively sifting,a modified sifting stop criterion is proposed here,and a method based on the improved Hilbert-Huang Transform is introduced for detection and analysis of power quality disturbances.The signal is decomposed into Intrinsic Mode Function by the improved empirical mode decomposition method,and the disturbance amplitude and frequency of corresponding time can be detected accurately and quantitatively.The experimental results show that this method can precisely localize the disturbance starting and ending time,lasting time and amplitude and is suitable for the monitoring system of power quality disturbance.