基于SVD的双-单端煤矿井下电缆故障定位

行波测距最重要的是时间和波速的确定。双端测距需要GPS授时系统,两端的授时误差增加了首波到达时刻的准确性。对电缆线路来说,行波的色散更加严重。而且不管单端还是双端测距,波速的确定对结果的影响都非常大。故障线路两端同时利用Hankel矩阵方式下对到达两端的电流行波进行奇异性分解(SVD)。每端分别得到首波及第二个波形到达的时间。SVD在不同的分解层上的奇异点结果不会发生偏移,克服小波变换随着分解层数增加带来的奇异点偏移缺点。波速的大小与频带关系紧密,行波信号经过小波分解再重构为多个频带的时域信号。在计算每个频带下前两个波头之间的相似度后,选取相似度最大的频带得到电缆的波速。在考虑线路时频特征对行波波速v的影响同时,提出双-单端故障测距。最后两端分别得到的故障点位置经过误差纠正算法,使得结果更加准确。

Double single-terminal traveling wave fault location of cable in coal mine based on SVD theory

The arriving time and the velocity are two main influences of wave traveling location. Two-terminal fault location needs timing system based on GPS,which will increase the timing error. For cable lines, the dispersion of traveling wave is more serious than overhead lines.In both single-terminal and double-terminal, the accurate of velocity has great impact on fault location. The wave traveling signal sigularity will be detected by SVD(Sigular Value Decomposition)when Hankel matrix is used.By which method,the time between fault initial traveling wave and reflected by the fault loction traveling wave was calculated.As is known, the wave speed is closely related to the band.Transient current signals generated by fault was decomposed by WDT(Wavelet Decomposed Transform) and then reconstructed in to different bands of time domained signals,in which the correlation coefficient of fault initial traveling wave and reflected by the fault loction traveling wave was computed. In those bands whose correlation coefficient was largest was selected as the characteristice band. On the basis of above, the double single-terminal fault location was proposed.Each single-terminal got a fault location length,then length of two sides processed by error