基于击穿间隙与可变电阻的配电网弧光接地故障建模分析

Modeling and Analysis of Arc Grounding Fault in Distribution Network Based on Breakdown Gap and Variable Resistance

摘要:

配电网弧光接地故障易引发森林火灾及人身触电等事故，弧光接地属时变、非线性故障，准确刻画弧光接地故障特征有利于提升配电网接地故障研究与模拟能力。针对传统的故障模型未考虑故障发展全过程，提出了基于击穿间隙与可变电阻的配电网弧光接地故障模型，考虑不同接地介质下弧光电压与电阻的发展过程，建立了击穿间隙与可变电阻解析方程。PSCAD/EMTDC仿真环境下验证表明，该弧光故障模型电流零休特征明显，电压具有显著的非线性畸变特点，反映了故障的发展特性。在10 kV配电网真型试验场进行弧光接地故障现场试验，并将现场试验数据与仿真数据进行对比分析，发现试验数据与模型数据拟合程度高，能真实刻画弧光接地故障特征，为配电网故障消弧、定位、选线奠定了基础，具有较强的实用价值。

关键词:接地故障;建模;电弧;击穿间隙;电阻

Abstract:

Arc grounding faults in distribution network are very harmful, Which may cause equipment explosions, fires and other accidents, and arc grounding is a time-varying and non-linear fault. Accurately characterizing arc grounding faults is beneficial to improve the research and simulation capabilities of grounding faults in distribution network. Aiming at the traditional fault model that does not consider the whole process of fault development, an arc grounding fault model of distribution network based on breakdown gap and variable resistance is proposed. Considering the dynamic development process of arc voltage and resistance under different grounding media, the breakdown gap and variable resistance equation is established. The verification under the PSCAD/EMTDC simulation environment shows that the arc fault model has obvious zerooff characteristics. At the same time, the field test data and the simulation data are compared and analyzed, and it is found that the model can truly describe the arc ground fault characteristics. It lays the foundation for the arc suppression, location, and line selection of distribution network, which has a strong practical value.

Key words:grounding fault; modeling; arc; breakdown gap; resistance