应用灭弧防雷间隙抑制弧光过电压的方法

当绝缘子发生雷击闪络造成单相接地故障时,间歇性电弧容易引发弧光接地过电压,对电网绝缘薄弱处造成破坏,影响电网安全运行。针对上述情况,设计了一种基于"疏导型"防雷理念和"气吹灭弧"相结合的灭弧防雷间隙。该间隙在快速疏导雷电流入地的同时,启动高速灭弧装置,熄灭故障点工频续流,抑制间歇性电弧产生和过电压。笔者通过对小电流灭弧试验和MATLAB建立的灭弧间隙仿真模型进行分析,灭弧防雷间隙可以抑制雷击闪络后引发的弧光过电压。

Approach to Inhibit Arc Grounding Over-voltage by Air-blast Interruption Gap

Single-phase ground fault of insulator due to lightning flashover will lead to arc grounding over-voltage by intermittent arc,which damages the insulation and harms the safe operation of power grid.Therefore,a parallel air-blast interruption gap was developed based on the idea of "conducting" type lightning protection and the "air-blast" arc interruption scheme.The gap can conduct lightning current into the earth rapidly,and meanwhile start the high-speed arc interruption device to interrupt continuous current at fault point and restrain inhibit intermittent arc and over-voltage.Experiment of small current arc interruption and MATLAB based simulation with the air-blast interruption gap model indicate that the air-blast interruption gap can inbibit arc grounding over-voltage caused by lightning flashover.