基于压缩感知估计行波自然频率的输电线路故障定位方法研究

摘要

提出了一种基于压缩感知估计行波自然频率的输电线路故障定位方法,能够准确估计多次行波自然频率,具有较高的故障定位精度.针对故障行波信号的频域特征设计了新的过完备字典,使行波信号能够被有效地稀疏表示.进行故障定位时,首先用小波模极大值方法确定故障行波信号的频率边界,并采用FIR滤波进行预处理滤除低频干扰成分,然后将其变换到频域使其能够在过完备字典上稀疏表示.在此基础上,该文利用改进的基于Dice系数的OMP算法(DOMP算法)对故障行波的频域信号进行重构,精确辨识行波信号的多次自然频率值,最终结合反射角和波速实现准确地故障定位.通过仿真分析验证了字典设计结合改进的DOMP算法的方法具有较高的定位精度和可靠性.%In this paper,a fault location method for transmission lines based on compressed sensing is proposed,it can precisely estimate the natural frequencies of multiple traveling waves with high accuracy of fault location.According to the frequency domain characteristics of the fault traveling wave signal,a new over-complete dictionary is designed to make the traveling wave signal sparse.When fault location is performing,use wavelet modulus maxima method to determine the boundary frequency of fault signals first,then use FIR filter to filter out low frequency interference and transform into the frequency domain to ensure it is in the over-complete dictionary sparse representation.On this basis,a modified OMP algorithm based on Dice coefficients (DOMP algorithm) is used to reconstruct a frequency domain signal of traveling waves and accurately identifies the natural frequency values of the traveling wave signal.Finally combine the reflection angle and the wave velocity to achieve accurate fault location.The simulation results show that the method of dictionary design combined with DOMP algorithm have high location accuracy and reliability.