基于台区剩余电流监测的接线错误用户漏电故障定位

Leakage Fault Location of Users With Abnormal Wiring Based on Residual Current Monitoring in Serving Zone of Distribution Transformer

台区漏电故障定位是供电企业运维中的痼疾。低压用户零线、地线接线错误是工程上的常见故障,可导致台区剩余电流超标,如不能准确定位将无法投入台区三级剩余电流保护,将严重威胁用户人身安全。既有漏电故障研究多围绕绝缘故障的电弧频谱特征展开,较少考虑接线错误因素影响。该文围绕农村TT接线台区的用户接线错误所致漏电故障,分析台区剩余电流在正常运行和用户接线错误条件下的波动特性。利用接线错误用户负荷电流主导台区剩余电流波动的特点,提出根据台区剩余电流和用户负荷电流进行回归分析定位接线错误用户的方法,将对台区剩余电流显著性影响程度高的用户识别为零线、地线接线错误用户。基于实验测试数据进行的仿真分析验证了所提方法的有效性。

Locating leakage faults in low-voltage distribution system is a bottleneck of power utilities.Abnormal wiring of neutral line and earth line of user is common in real world.It could cause leakage current larger than threshold of residual current devices(RCD),leading to nuisance tripping.Since it is rather difficult to locate fault results in residual current,a large number of RCDs are put out of service,which endangers users’safety at large.Frequency characteristics of arc current induced by insulation failure have been investigated thoroughly in existing literature.However,impact of user of wiring fault has not been analyzed.Fluctuation of leakage current with and without users of abnormal wiring in TT earthed distribution system is analyzed.It is found that the leakage current is determined by the load current of the anomaly user at large.A residual current monitoring based approach is proposed in the paper to locate users of abnormal wiring with data mining of leakage current and load current of users.Users who have a significant impact on the residual current with high degree of significance will be identified as users of abnormal wiring.Numerical simulation of experimental data demonstrates performance of the proposed approach.