小电流接地系统单相接地故障特征分析及其应用

Characteristic Analysis of Single-phase Grounding Fault in Small Current Grounding System and Its Application

小电流接地系统单相接地故障是一种典型的多发故障,长时间带故障运行可能引起整个系统的过电压,造成设备损坏等。本文基于单相接地故障的特点,从理论上分析了不接地系统、谐振接地系统,并量化分析暂稳态的零序电流值、故障前后配电网中各电气量的变化以及各馈线的故障特征。最后,应用本文方法对于一实际故障进行分析结果表明,选出恰当的角度对故障信息进行提取并定制合适选线方案具有一定意义。

The single-phase grounding fault in small current grounding system is a typical frequently-occurring faults.Long-term operation of the system with this fault may cause the over-voltage of the whole system and lead to equipment damage.Based on the characteristics of the single-phase grounding fault,theoretical analysis is carried out on non-grounding system and resonant grounding system.Quantitative analysis is also conducted on the transient and steady state zero sequence current values,variation of various electrical quantities in the distribution network before and after the fault,as well as the fault characteristics of each feeder line.At last,the proposed method is adopted to analyze an actual fault.The results show that the proposed method has certain significance in selecting appropriate angles for extracting fault information and customizing appropriate line selection schemes.