基于潮流计算的直流配电网单极接地故障定位算法

A fault location algorithm for the single-pole-to-ground fault of DC distribution network based on power flow calculation

提出了一种基于潮流计算的直流配电网单极接地故障定位算法。通过分析流过接地故障点的电流特征,发现故障暂态过程结束后,故障点对地电压近似为零。利用潮流计算得到负荷电流分布,配合故障点对地电压近似为零的条件,计算每个节点故障时各个测量点对地残余电压的分布情况。将其与故障时各测量点残余电压分布情况进行比较,一致性最高的即为距实际故障点最近的节点。进一步利用阻抗法确定故障点的准确位置。在Matlab/Simulink中搭建仿真模型,仿真结果验证了该算法的有效性。

This paper presents an algorithm of locating single-pole-to-ground faults in DC distribution network based on power flow calculation. The fault current feature flowing through fault point is analyzed, implying the pole-to-ground voltage at the fault point of fault pole is almost zero when the transient process ends. Given this precondition, the distribution of residual voltage of each measuring point in fault pole can be calculated with the load current, which is obtained by power flow calculation. By comparing the similarity between the distribution and the measured residual voltage distribution in real fault, the node which makes the maximum similarity is identified to be closest to the real fault point. An impedance-based method is applied further to calculate the accurate location of fault point. Simulation model is established based on Matlab/Simulink, and the test results demonstrate the validity of proposed algorithm.