中性点经高阻接地电网故障电弧建模与弧光接地分析

中压配电网绝大多数故障为电弧接地故障,针对Cassie与Mayr这两个经典电弧模型在单独使用时只能考虑到对流散热或传导散热,具有片面性,而二者结合使用却恰好可互补,故而在ATP-EMTP平台下将这两种模型进行搭配并合理设置。通过仿真,分析研究了中性点经高阻接地配电网单相电弧故障时的特性,并将电弧模型用于间隙性电弧接地故障仿真,符合实际情形,证明了电弧模型可有效地反映弧光接地过电压,及小电流接地系统中中性点电阻对降低电网弧光过电压的作用。

An Analysis on Arc Modeling and Arc Light Grounding for Grid Faults of High-resistance Grounding of the Neutral Point

Most of the faults in the medium-vohage power distribution network are arc grounding fauhs. Classical arc model Cassie and Mayr, when used separately, can only consider thermal convection or thermal conduction- one-sidedness. But, when used in combination, they can complement each other. In this paper, therefore, these two models are used in a reasonable setup on the ATP-EMTP platform. Through simulation, this paper analyzes the characteristics of the single-phase arc fault in distribution network with high- resistance grounding of the neutral point, and uses this arc model in the simulation of intermittent arc grounding fault according to actual circumstances. It is proved that this arc model can reflect the over-voltage caused by arc light grounding, and that in the small- current grounding system, the resistance of the neutral point can reduce the over-voltage of the grid arc light.