动态小波变换在单相重合闸故障判别中的应用研究

分析了输电线路发生单相接地故障时,永久性故障与瞬时性故障电弧燃烧的特性,提出一种基于动态小波变换的自适应单相重合闸故障类型的判别方法。小波变换能够准确地检测到电力系统故障突变信号的特征,而傅里叶变换能够较准确地反映工频信号量,将二者结合起来构成的动态小波变换,不仅可以检测到故障信号中的工频分量,还可以检测到谐波分量。动态小波变换与常规小波变换相比,检测故障突变信号的能力更强。将其用于单相重合闸故障类型的判别,可以在熄弧之前进行判断,具有快速、准确的显著特点。仿真结果验证了该方法的有效性。

Study and Application of Dynamic Wavelet Transform Based on Single-phase Reclosure Faults Distinguishment

The formation of the arc voltage in temporary and permanent single-phase faults were analyzed.A novel method based on the dynamic wavelet transform to identify fault types for the adaptive single-phase reclosure on transmission lines,was proposed.The wavelet transform can detect the characters of the fault singular signals in power system,and the Fourier transform can exactly detect the power frequency signals.The dynamic wavelet transform includes the wavelet transform and the Fourier transform,then it can detect the harmonic signals and power frequency signals on transmission lines.Compared with the wavelet transform,the dynamic wavelet transform can detect the fault singular signals much stronger in detecting fault types.The dynamic wavelet fransform work before the extinction of the arc when used for identification of single-phase reclosure faults,was characterized by fast speed and accuracy.The simulation results demonstrated its validity.