基于并联中值电阻的小电流接地故障选线技术

Small Current Grounding Fault Line Selection Based on Paralleled Medium Resistancer

小电流接地故障,电力系统尤其发生间歇性弧光接地故障时,线路过电压会引起电力设备出现新的接地点,导致接地故障恶化,因此线路发生故障后迅速找出故障线路对系统安全占有重要地位。本文首先详细分析了在中性点处增加电阻对小电流接地系统的影响规律;其次,提出一种基于并联中值电阻的输电线路发生小电流接地故障的选线方法;最后,搭建了6kV小电流接地系统故障选线的三相仿真模型,通过仿真结果的对比,进一步说明了基于中性点并联中值电阻的小电流接地故障选线技术能够较为准确地确定故障线路。

Small current grounding fault,power system occurs especially intermittent arc earth fault,the line over-voltage electrical equipment can cause the emergence of new ground,resulting in the deterioration of the earth fault,thus quickly identify the fault line of the security system plays an important role after the line failure. This paper analyzes the increased resistance at the neutral point of the influence of small current grounding system;Secondly,line selection method based on paralleled medium resistancer in parallel with the transmission line has a small current ground fault;and finally,build a small 6kV Three-phase simulation model grounded fault line Selection. By comparing the simulation results further illustrate can accurately determine the fault line based on paralleled medium resistancer in parallel with the neutral point of the small current grounding fault line selection.