The fault line selection of single-phase grounding fault in 10 kV distribution network has not been well solved, due to which fault condition intricately and fault current too small. On the basis of analysis to fault transient characteristics of system when occur single-phase-to-earth fault, the single phase grounding fault of power system with neutral grounding via arc suppression coil is simulated. A method of single- phase grounding line selection in small current grounding system was put forward, based on comparison difference of transient zero sequence current absolute value of each line in a power frequency cycle. At the same time, principle and procedure of fault line selection of the method were introduced. The MATLAB Simulations indicate that the method can find out the faulty line correctly. It has a high sensitivity and cannot be affected by fault resistances and fault current angles and other factors.%10 kV配电网发生单相接地故障时,由于接地电流很小,加之故障情况较复杂,其选线问题一直未能很好地解决.在分析系统发生单相接地故障暂态特征的基础上,对中性点经消弧线圈接地系统发生单相接地故障进行了仿真.提出了一种利用比较各线路暂态零序电流在一个工频周期内绝对值比较的故障选线方法.阐述了该选线方法的原理与步骤.通过MATLAB仿真试验表明,该方法可以准确实现故障选线,具有较高的灵敏度,且不受过渡电阻和故障合闸角等因素的影响.
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