王建元,张峥.基于注入信号与小波能量的小电流接地故障选线研究[J].电测与仪表,2018,55(5):28-32. wangjianyuan,zhangzheng.Research of Fault Line Selection in Small Current Grounding System Based on Injected Signal and Wavelet Energy[J].Electrical Measurement & Instrumentation,2018,55(5):28-32.
基于注入信号与小波能量的小电流接地故障选线研究
Research of Fault Line Selection in Small Current Grounding System Based on Injected Signal and Wavelet Energy
Abstract：In order to solve the problem that traditional injection method can't select line correctly because of signal sub-flow when single phase high resistance grounding occurs in the small current grounding system,this paper proposes a new method of fault line selection which combines injection method and wavelet energy method for distribution network after analyzing the principle of line selection by the two methods in detail.In this paper the 220Hz special frequency signal was injected into the fault system firstly and the injected signal from every feeders was extracted to be wavelet transformed,then the wavelet low frequency energy was calculated by the wavelet coefficients.Finally the line was selected by comparing the size of energy among the feeders.The study processed simulation experiments trough using the the system model built by Simulink.The result shows that the new method of fault line selection is not affected by the fault distance, the fault angle size and the neutral point grounding mode.Although the line selection is still failed when the transition resistance is larger but the problem can be solved well through phase comparison method or image recognition method,which will improve the accuracy of line selection by the injection method.
