基于行波时差法的配电网故障诊断方法

Distribution Network Fault Diagnosis Based on Traveling Wave Time Difference Method

针对配电网结构复杂故障难以精确诊断的问题,提出了一种基于故障行波时差的配电网故障诊断方法,实现对配电网故障点的精确定位及故障类型的判断。根据线路行波传输特性及故障点距离计算理论,构建配电网线路状态方程,将计算的理论值代入状态方程,输出故障搜索矩阵,利用矩阵变化的特征来诊断线路的故障情况。最后,利用行波到达多端时刻差解决线路中波速变化造成的故障定位不准确问题。该方法经配电网仿真模型验证具有有效性,可以准确诊断出不同阻值接地故障。

In view of high difficulty in accurately diagnosing faults in distribution networks with complicated structures,a fault diagnosis method based on traveling wave time difference is proposed,which can realize accurate location of fault points and identification of fault types.According to line traveling wave transmission characteristics and fault point distance calculation theory,state equation of distribution network lines is constructed,through which the fault search matrix is obtained using the calculated theoretical values.Thereby the line′s fault state can be diagnosed based on characteristics of matrix change.Finally the traveling wave arrival multi-terminal time difference is used to overcome the problem of inaccurate fault location caused by varying wave speed in the line.Through a simulation model,the method is verified to be effective and capable of diagnosing grounding faults with different resistance values.