基于LMS形态滤波和Hilbert变换的电能质量扰动定位

摘要

针对电能质量中常见的几种暂态扰动，为了实现对其正确地检测和定位，提出了一种最小均方（LMS）自适应形态滤波和Hilbert变换相结合的方法。首先，扰动信号中往往夹杂中各种噪声，采用基于LMS算法的广义形态学滤波器对扰动信号进行降噪处理。然后，对降噪后的信号进行Hilbert变换，提取扰动信号的幅值包络，可以实现对扰动的初步定位。最后，对提取的幅值包络进行后向差分处理，形成定位脉冲，实现对暂态扰动起止时刻和持续时间的精确定位。通过在不同条件下的仿真对比实验，证明了该方法的有效性。%For the common kinds of transient disturbance in power quality, in order to realize the detection and lo⁃cation correctly, this paper presents a method combining adaptive generalized morphological filter based on LMS (least mean square)and Hilbert transform. Firstly, the disturbance signals are mixed with all kinds of noise and the generalized morphological filter based on LMS is used to filter the noise. Then, it makes the signals with Hilbert transform and extracts amplitude envelope of the disturbance signals which can realize preliminary positioning of the disturbance. Finally, it makes amplitude envelope with the backward difference which forms the positioning pulse and realizes positioning the begin-end time accurately. The simulation experiments under different condi⁃tions have proved the effectiveness of the proposed method.