基于db4小波的电能质量去噪及暂态扰动的检测

Power quality denoising and transient disturbance detection based on db4 wavelet

本文针对暂态电能质量扰动信号具有时间短、变化快、非平稳等特性,采取一种基于db4小波分析的暂态电能检测方法。根据Mallat算法,信号奇异点处的小波变换模极大值能够通过信号的多分辨率分解提取出来,实现暂态电能质量信号扰动时间的准确定位,扰动定位前根据信号与噪声在小波变换各尺度上有不同传播特性,对电能信号小波去噪。利用Matlab编程对5种暂态电能质量扰动信号进行暂态扰动检测的仿真分析,结果表明该方法能够准确的获取扰动的起止时间,精度满足实际的工程需求。

Aiming at the characteristics of short time,fast change and non-stationary of transient power quality disturbance signal,a transient power detection method based on db4 wavelet analysis is proposed.According to Mallat algorithm,the modulus maxima of wavelet transform at singularity points can be extracted by multi-resolution decomposition of signals,and simultaneous interpreting the disturbance time of transient power quality signals.Before the disturbance location,the signals can be denoised by wavelet denoising according to the different propagation characteristics of signals and noises in different scales of wavelet transform.The simulation analysis of transient disturbance detection for five kinds of transient power signals is programmed on MATLAB,.The simulation results show that the method can accurately obtain the start and end time of disturbance,and the accuracy meets the actual engineering requirements.