基于小扰动原理的单相接地选线装置

在有消弧线圈的配电网中,快速选线技术是一项关键技术。通过对中性点不接地系统和中性点经消弧线圈接地系统线路发生单相接地故障的分析,提出了一种小扰动选线原理。介绍了运用该原理,以DSP(数字信号处理器)芯片作为核心运算控制单元的单相接地选线装置的选线原理、方法以及硬件构成原理。并详细分析了该装置在现场(中性点经KD-XH消弧线圈接地的系统)运行的情况,实践证明了该装置的选线正确率达到96%以上。该装置适用于电网电容电流变化范围大、小电容电流、高阻接地的配电网系统。

Single-phase grounding selected-line equipment based on small disturbance theory

In the distribution network with an arc suppressing coil,quick line selection technology is very important.After the analysis of the single-phase earth fault in the system of neutral point non-connecting-to-earth and the system of neutral point connecting-to-earth via arc suppressing coil,this paper puts forward the small disturbance theory.Based on this theory,the line selection theory,method and hardware construction of selected-line equipment for single-phase grounding fault are also introduced,which adopts digital signal processing(DSP) as a control unit.There is a detailed analysis of the operation of the equipment in the system of neutral point connecting-to-earth via KD-XH arc suppressing coil,and the result proves an accuracy of 96% of line selection with the equipment.The equipment is applicable for the distribution network of small capacitance current,grounding through high resistance and the capacitance current of which varies greatly.