基于脉冲发射原理的配电网故障定位方法的研究

在小波理论的基础上,提出了配电网行波故障定位方案。在故障相的线路首端发射脉冲信号,采集线路首端的行波信号,利用小波消噪原理对采集到的行波信号进行滤波,比较线路正常时的行波信号和线路故障时的行波信号,利用小波变换对信号奇异性的检测原理找出行波信号中的奇异点,得到故障距离。对结构简单的线路,在此基础上分析特征波即可准确定位;对结构复杂的线路,在确定故障距离的基础上,根据电网拓扑划定故障可能的几个分支。然后在线路首端注入电流,通过探测器检验几个分支上是否有电流流过,检测到电流的即为故障点所在的分支。详细分析了该行波定位方案在两次现场试验的应用结果,证明了该方案的可行性。

A new scheme of travelling wave fault location for distribution network based on wavelet transform

On the foundation of wavelet theory,this paper puts forward a new scheme of travelling wave fault location for distribution network.On the head of fault phase,it firstly projects the pulse signal,gathers the signal of travelling wave,eliminates the noise of travelling wave by using wavelet transform,compares the signal of travelling wave between the normal and the fault,and detects the singularity of travelling wave by wavelet transform.And then the fault distance can be obtained.For the simple lines,the fault point can be located accurately by analyzing feature wave on this foundation.For the complex lines,it delimits the possibility of fault branches according to the topology of electrical network,after determining the fault distance.After injecting current into the head of line,the detector can check whether these branches flow current,the fault branch is that the current has flowed.The applications of this scheme result in the lines on-the-spot is detailed,which proves the feasibility of this scheme.