不接地系统单相断线故障分析及区段定位

Analysis and fault section location of single-phase open fault for ungrounding system

由于绝缘导线的应用,配电线路断线故障发生概率增大,现场缺乏有效的检测技术措施。针对不接地系统,建立了单相断线不接地故障模型。在考虑断线位置、故障线路对地电容占系统总对地电容的比例和负载阻抗的大小及其分布等因素的影响下,分析了中性点偏移电压、断口前后相电压以及线电压的变化规律。根据相电压和线电压的变化规律分别提出单相断线不接地故障区段定位的方法。所提方法可利用配电网自动化平台或者故障指示器系统实现,提高了断线故障区段定位的可靠性和适应性。最后用Matlab仿真验证了方法的正确性。

Due to the application of insulated wire,the occurrence probability of line break faults in distribution lines increases.There are no effective method to detect line break fault on site.In this paper,based on ungrounding system,a model of single-phase line break fault without grounding is established.Line break location,the ratio of the fault line grounding capacitance to system grounding capacitance,load impedance magnitude and distribution factors are taken into consideration.Variation characteristics of offset voltage at neutral point,line voltage and phase voltage of the line break point are analyzed.According to the variation characteristics of line voltage and phase voltage,this paper proposes fault section location methods respectively to detect single-phase line break fault without grounding.This proposed method can be realized through distribution automation platform or malfunction indicator system,which improves the reliability and applicability of line break fault section location.In the end,this method is verified by Matlab simulation.