中压电缆网接地故障的电弧建模及仿真研究

Arc modeling and simulation of the ground faults of the middle voltage cable network

在中压电缆网络中,很容易发生单相接地故障,其中电弧接地故障所占比例较高,且其过程复杂,难以模拟。为此提出了新型小电流方式电弧模型。研究了现有的经简化的电弧模型,并用Matlab对现有模型进行仿真分析。在此基础上,以小电流接地方式的中压电缆网络为背景条件,对电弧模型的参数进行改进,得出电弧模型的电压电流特性,用Matlab对改进后的电弧模型进行验证。与实际情况的物理量进行比较,证明所得改进电弧模型的可应用性。仿真结果证实所提出模型能更合理地贴近于真实故障情况,为下一步电缆网络故障分析的研究奠定了重要技术基础。

In the MV cable network, it is easy to have phase-to-ground faults, of which the ratio of arc grounding faults is high. What＇s more, the process of it is complex and difficult to simulate. As a result, a new arc model for the small current neutral grounding mode is put forward. This paper studies the existing simplified arc models and simulates the arc models with Matlab. On this basis and in the background of MV cable network with the small current neutral grounding mode, the parameters of the models are improved. Then the voltage and current characteristics of the arc model are got. The model is verified with Matlab. Compared with realistic physical quantities, it can be proved that the improved arc model is applicable. The result affirms that this model is closer to the reality. It is an important technical basis for the study of the next step of cable network fault analysis.