基于SCADA系统的小电流接地故障选线方法研究

Fault line selecting method in non-solidly-earthed network based on SCADA system

为了有效改善调度员仍然采用“拉路”法进行选线的现状,利用各级调度机构已有的SCADA系统获取线路的稳态零序电流,提出了基于调度SCADA系统的小电流接地选线方法。新的选线方法能够应用于中性点不接地和中性点经消弧线圈接地的小电流系统,通过比较各条线路稳态零序电流幅值和变化量辨识故障线路,最多1次拉路操作就能确认故障线路。截至目前,武汉电网已有19座变电站开始应用新的选线方法进行选线,累计14次单相接地故障全部判断正确。实际选线案例和应用过程表明,该方法准确有效,具有广泛的适用性和推广性。

In order to effectively improve the situation of dispatchers using the"Pull Line"method for line selection,the SCADA system of all levels of dispatching agencies is used to obtain the steady zero-sequence current of the line,and a small current grounding line selection method based on the dispatching SCADA system is proposed.The new line selection method can be applied to small current systems where the neutral point is not grounded and the neutral point is grounded via the arc suppression coil.By comparing the steady zero-sequence current amplitude and variation,the fault line can be confirmed by up to 1 pull operation.Up to now,19 substations in Wuhan Power Grid have begun to apply new line selection methods for line selection,and all the 14 single-phase ground faults have been judged correctly.The actual line selection case and application process show that the method is accurate and effective,which could be widely applied and promoted.