煤矿井下激励式漏电与防越级保护系统的应用研究

Research on Application of Underground Excitation Type Leakage and Anti Skip Protection System in Coal Mine

为了解决井下短路引起的越级跳闸和高低压漏电引起的开关无规律跳闸事件,提高煤矿供电系统的安全性,本文对煤矿井下激励式漏电与防越级保护系统进行应用研究。通过在变电所间建立数字光纤防越级专网,使各级保护间能够信息交互与协商,快速定位故障分支,迅速切除故障回路,避免大面积停电,实现分布式智能防越级保护系统。通过对单相接地或单相对地绝缘降低线路注入异频电流信号,与接地故障点形成电流回路,接地线路异频信号明显大于非接地线路,各线路保护利用检测异频信号大小,判断出故障线路并予以跳闸切除,实现激励式漏电保护系统。通过与传统方法进行对比实验,结果表明当发生异常或者故障时,该系统可以在更短的时间感应与确定故障线路,及时跳闸,避免较大损坏的出现,具有实际的应用意义。

In order to solve the occurrence of skip tripping caused by underground short circuit and irregular switch tripping caused by high and low voltage leakage,and improve the safety of coal mine power supply system,this paper studies the application of underground excited leakage and anti skip protection system.Through the establishment of digital optical fiber anti skip level special network between substations,the protection at all levels can exchange and negotiate information,quickly locate the fault branch,quickly cut off the fault circuit,avoid large-area power failure,and realize the distributed intelligent anti skip level protection system.By injecting different frequency current signal into the single-phase grounding or single phase grounding insulation reduction line,a current loop is formed with the grounding fault point.The different frequency signal of the grounding line is significantly larger than that of the non grounding line.Each line protection uses the detection of different frequency signal to judge the fault line and trip it to realize the excitation leakage protection system.Compared with the traditional methods,the results show that in case of abnormality or fault,the system can sense and determine the fault line in a shorter time,trip in time,and avoid the occurrence of large damage,which has practical application significance.