小电流接地系统输电线路故障定位新方法

New Method of Transmission Line Fault Location for Small Current Grounding System

在分析小电流接地系统单相接地故障暂态零模功率特性的基础上,提出了一种利用暂态零模功率求取相关系数进行故障定位的方法。该方法利用故障点上游或下游两检测点的暂态零模功率波形相似度高,相关系数值接近于1;而故障点两侧检测点的暂态零模功率波形差异较大、相关系数值小这一特征,将相邻两检测点求得的相关系数值与事先设置好的阈值做比较,若大于阈值即判为非故障区段,若小于阈值则判为故障区段。该方法原理简单,工程实用性强。另外,通过数字仿真试验得到的数据也验证了该方法的正确性。

Based on the analysis of the transient zero-mode power for single-phase grounding fault of small current grounding system,a fault location method is proposed to utilize transient zero-mode power to calculate the correlation coefficient.The method takes advantage of the features that the transient zero-mode power of two detection points is highly similar at the upstream or downstream of fault location,and the value of correlation coefficient is close to 1,while the waveforms of both sides are quite different at the fault location,and the value is small,to compare the calculated value of two adjacent detection points with the threshold value.If the value is larger than the threshold,the section is judged as non-fault;otherwise,it is judged as fault section.The method adopted in the paper is simple in theory and useful in engineering practice.Besides,the correctness of the method is also verified by the data simulation.