基于突变量波形互异性的故障定位新方法

A New Method of Fault Location Based on the Dissimilarity of Waveform of Sudden Variable

在谐振接地系统中,利用波形相关性选线定位存在判据裕度不足,易引起误判的问题。根据系统发生单相接地故障时,故障上游三相电流突变量波形间差异性与故障下游三相电流突变量波形间差异性的不同,提出了基于突变量波形互异性的故障定位新方法。首先定义了各相互异参数与各相邻两检测测点之间的故障测度,通过提取线路上各检测点的三相电流突变量,算取每检测点三相电流突变量之间的互异参数,然后计算各检测点之间的故障测度。仿真结果显示纯线路或混合线路故障时故障区段相邻两检测点之间的故障测度最大,而非故障区段相邻两检测点之间的故障测度均接近于1。因此可知此方法判据裕度裕度较高,不易发生误判,也能适用于混合线路故障区段检测。

In the resonant grounding system, the problem of the insufficient criterion margin for the line selection by the waveform correlation exists, which could cause the problem of false detection. According to the principle that the variability between the sudden variables of three phase currents in the upstream is different with in downstream when the single-phase grounding fault occurs in the system, a new method for fault location based on the dissimilarity of waveform of a sudden variable is proposed. Firstly, this paper defines the dissimilarity parameters and the fault measure between the two adjacent points. Then the dissimilarity parameters between the sudden variables of three phase currents of each detection point are obtained after the sudden variables of three phase currents are extracted from every detection point. Finally, the fault measure between the two adjacent points is calculated. The simulation results show that fault measure between the two adjacent detection points in the fault section is the largest under the situation of the fault pure lines or hybrid lines, and the fault measure between the adjacent two detection points in the non-fault section is close to one. Therefore, this method has the higher criterion margin, and it is not easy to cause the problem of false detection. What＇ s more, it can be applied to the fault section detection for hybrid lines.