CAJ | 학술논문

分析了配电网络发生单相接地故障后故障行波的传输模型,由于配电网暂态行波信号微弱,提出了利用小波变换后图形相关性方法,检测行波波头的时间差.首先对暂态电流做多次小波变换,对小波变换后的图形去除噪声,然后提取出该图形中的峰谷波形,利用第1个峰谷波形作为基准量,后续的波形依次与第1个波形做相关性分析,找出与第1个峰谷波具有最大相关的波形,利用此波形和第1个波形的时间差作为测距的依据,通过A型行波测距算法算出故障距离.ATP仿真结果表明,采用小波变换后的波形相关性算法可将测距误差限制在±100m的范围内;而且,利用该算法可以消除过渡电阻和故障发生在电压过零导致的测距结果失真.
분석료배전망락발생단상접지고장후고장행파적전수모형,유우배전망잠태행파신호미약,제출료이용소파변환후도형상관성방법,검측행파파두적시간차.수선대잠태전류주다차소파변환,대소파변환후적도형거제조성,연후제취출해도형중적봉곡파형,이용제1개봉곡파형작위기준량,후속적파형의차여제1개파형주상관성분석,조출여제1개봉곡파구유최대상관적파형,이용차파형화제1개파형적시간차작위측거적의거,통과A형행파측거산법산출고장거리.ATP방진결과표명,채용소파변환후적파형상관성산법가장측거오차한제재±100m적범위내;이차,이용해산법가이소제과도전조화고장발생재전압과령도치적측거결과실진.
The transfer model of travelling wave is analyzed for the single-phase grounding fault of distribution network.Because the transient travelling wave signal is very weak,an algorithm that uses Wavelet transform and graphic correlation to detect the time difference of wave heads is proposed.The transient zero sequence current is wavelet-transformed several times to remove the noises in the graphics after wavelet-transforiB.With the first peak-valley figure as reference,the correlation analysis is carried out for following peak-valley figures to find out the most correlated one.The time difierence between them is used to calculate the fault distance using A-type travelling wave fault locating algorithm.Simulative results with ATP show that its error is within ±100 m,immune to the influences of transient resistance and fault voltage phase near zero-cross.