基于小波理论的输电线路故障信号检测的研究

输电线路发生故障后,其行波信号是一个突变的、具有奇异性的信号。小波分析具有很多有用的性质,利用小波多分辨率的特性可将突变信号进行多尺度分解,然后通过分解后的信号来确定突变信号的突变位置。Lipschitz指数被用来定量描述函数的奇异性。当小波变换尺度越来越精细时,小波变换模的极大值信号的突变点位置越精确。其衰减速度取决于信号的突变点的Lipschitz指数。小波变换不仅可以确定突变位点发生的时间,而且可以进一步判断突变点的性质。通过检测小波变换模极大值来找到信号的奇异点,从而确定信号发生突变的位置。

Research on Fault Signal Detection in Transmission Line Based on Wavelet Theory

After the failures occurring in the transmission lines,its traveling wave signal is a sudden-change signal with singularity.Wavelet analysis has many useful properties.Using the characteristics of wavelet multi-resolution,the multi-scale decomposition can be carried out for the sudden-change signal,and the location of the sudden-change signal can be determined through the decomposed signal.Lipschitz index is used to quantitatively describe the function of the singularity.When the scale of wavelet transform is more and more fine,the location of the sudden-change point is more precise.The rate of decay depends on the Lipschitz index of the sudden-change signal.Wavelet transform not only can determine the time that the sudden-change point occurs,but can further determine the nature of sudden-change point.Through detecting the modulus maxima of wavelet transform,the singular point can be found,and the location of the sudden-change signal can be determined.