CAJ | 학술논문

由于小电流接地系统单相接地故障的故障电流小、故障过程持续时间短,且影响故障选线准确率因素多,采用常规的故障选线方法其准确率较低而采用暂态零序电流小波变换方法是目前研究的热点,可实现故障选线的准确性.为研究此一技术,在分析单相接地故障暂态电流特征的基础上,根据暂态电流行波幅值比较式方向保护选线原理,在MATLAB SIMULINK平台上建立了不同馈线10 kV配电网络的模型,利用Haar小波分析方法对2～30回馈线的10 kV配电网络进行了仿真分析.结果表明,Haar小波可实现单相接地故障准确选线的目的,故障选线结果与配网的馈线数无关,选线的准确性与小波窗时间宽度有关,因此采用Haar小波进行故障选线时应根据系统的接地方式和配网的馈线数量合理调整小波窗时间宽度.
유우소전류접지계통단상접지고장적고장전류소、고장과정지속시간단,차영향고장선선준학솔인소다,채용상규적고장선선방법기준학솔교저이채용잠태령서전류소파변환방법시목전연구적열점,가실현고장선선적준학성.위연구차일기술,재분석단상접지고장잠태전류특정적기출상,근거잠태전류행파폭치비교식방향보호선선원리,재MATLAB SIMULINK평태상건립료불동궤선10 kV배전망락적모형,이용Haar소파분석방법대2～30회궤선적10 kV배전망락진행료방진분석.결과표명,Haar소파가실현단상접지고장준학선선적목적,고장선선결과여배망적궤선수무관,선선적준학성여소파창시간관도유관,인차채용Haar소파진행고장선선시응근거계통적접지방식화배망적궤선수량합리조정소파창시간관도.
When a one-phase-to-ground fault of an indirectly grounding 10 kV power system occurs, the fault current is small and the fault duration is short. Furthermore, because many other factors influence the accuracy of the fault detection, the common methods of the fault location have low accuracy. The wavelet transform analysis based on the transient zero-sequence current that could increase the accuracy of the fault location is investigated. On the basis of the transient current characteristic analysis of one-phase-to- ground fault and according to the fault location principle of the transient current traveling wave amplitude comparison director protection, we established multi-feeder 10 kV power system models on MATLAB SIMULINK,and simulated from two up to thirty feeders with Haar wavelet.The simulation shows that Haar wavelet could locate the earthed fault feeder effectively. The results indicate that the feeder numbers have little influence on the fault detection, and the accuracy of the fault location is determined by the width of the wavelet time-window. Therefore,when the Haar wavelet is used for the earthed fault detection, the width of the wavelet time-window should be adjusted effectively according the grouding patterns of the neutral point and the feeder number of the power system.