中性点不接地电网在线故障定位研究

Research on fault location online for neutral point ungrounded system

随着用户对供电质量要求的不断提高,在线解决配电网故障定位问题成为供电部分的迫切需要。对中性点不接地配电系统发生单相接地故障进行了分析,得出了各支路零序电流与零序电压之间的幅值相位关系,进一步提出了移动式的比幅比相在线故障定位方法。该方法将比幅、比相和仿真比较法优势互补,使得定位不受线路接线的影响,不受接地电阻的影响,提高了定位的可靠性。ATP仿真验证了该方法的有效性。

Fault location on line for distribution network is necessary with the improvement of demand for the reliability of the power supply. By analyzing the single-phase-to-earth fault of neutral-ungrounded system, this paper drew the relationship between the zero sequence current and the zero sequence voltage, and then proposed the method of magnitude and phase comparison which was implemented by using the mobile zero sequence CT and wide area phase measurement. The method takes advantages of three methods and has no influence by the system structure and little influence by the fault resistor. The method has been proved to be valid by simulation.