摘要
当小电流系统单相接地故障时,由于故障电流较小、电气量不明显,且系统运行方式多样、结构较为复杂,难以对故障点加以判断。当前,主要依靠人工巡线的方式确定故障点,不仅费时费力,还难以快速、准确地寻找故障位置。对此,利用单相接地故障位置前后线路流过的零序电流差异较大,使故障端前后两侧检测点流过的零序电流波形差别大,而同侧线路零序电流波形相似。利用各区段两侧故障发生后2个工频周期内的零序电流数据,分时段计算幅值,并以积分算法求取幅值积分系数,最终根据幅值积分系数判断故障区段。试验结果表明:该方法对不同接地电阻、不同补偿度、不同故障初相角下的单相接地故障的定位准确度高,在高阻接地、线路末端接地以及电弧性接地故障时仍能适用。该方法只需线路上的零序电流信号,信号获取方便;只需上传检测点幅值积分系数,数据传输量小。该研究也符合智能配电网的进一步发展趋势。
In the case of single-phase grounding fault of small current system,because the fault current is small,the electric quantity is not obvious,and the system operates in various ways,the structure is complex,and it is difficult to judge the fault point.At present,the fault point is determined mainly by means of manual inspection,which is not only time-consuming and laborious,but also difficult to find the fault location quickly and accurately.In this regard,the zero-sequence current flowing through the line before and after the single-phase grounding fault position is large,so that the zero-sequence current waveform flowing through the detection points on the front and rear sides of the fault end is large,and the zero-sequence current waveform of the same side line is similar.Using the zero-sequence current data in the two power frequency cycles after the faults on both sides of each section,the amplitude is calculated in time-divided,and the integral coefficient is obtained by the integral algorithm.Finally,the fault section is judged according to the amplitude integral coefficient.The test results show that under the conditions of different grounding resistances,different compensation degrees and different fault initial phase angle,the positioning accuracy under single-phase grounding fault is high;and it can still be applied to high resistance grounding,line end grounding and arc grounding faults.With this method,only the zero-sequence current signal on the line is needed,and the signal acquisition is convenient;it only needs to upload the integral coefficient of the detection point's amplitude,and the data transmission amount is small,it is in line with the further development trend of intelligent distribution network.
作者
闫丽梅
张琰骏
徐建军
杨帆
YAN Limei;ZHANG Yanjun;XU Jianjun;YANG Fan(School of Electrical Engineering & Information,Northeast Petroleum University,Daqing 163318,China)
出处
《自动化仪表》
CAS
2019年第8期89-93,共5页
Process Automation Instrumentation
基金
国家自然科学基金资助项目(51774088)
关键词
小电流接地系统
单相接地故障
相似性
故障电流
零序电流
故障区段
幅值积分系数
Small current grounding system
Single-phase grounding fault
Similarity
Fault current
Zero sequence current
Fault section
Amplitude integral coefficient
