Fault Detection Of Xing Tai Distribution Gird Based On Feed Line Automation Simulation System

After the fault occurs in the distribution network,the timely detection and isolation of the fault can reduce the risk of accident expanding through of the distribution network,which can improve the automation level.In the distribution network,the probability of single phase short circuit fault is high,so it is of great significance to study the fault line selection under single phase short circuit fault.Affected by the purity of the fault signal and the amplitude of the signal,as well as the complex and variable operation mode and interferenc e factors,fault line selection has its difficulty.In order to find a better detection method,which could adapt to the situation of Xing Tai distribution network,the method of fault line detection is studied for distribution network in Xing Tai city.The method has reference significance for the construction of Xing Tai distribution automation and intelligence.At first,the characteristics of neutral grounding mode of power system are studied,the conditions and the selection basis of various grounding mod es are analyzed;According to the different grounding modes,the electrical characteristics of the fault are summarized;The current situation of line selection of single phase to ground fault in Xingtai distribution network are analyzed and the existing methods of line selection are studied,and the problems of “inter stop method” are pointed out.Secondly,according to the characteristics of the electrical quantity after single-phase short circuit grounding fault,it is focused on the fault line selection method based on the characteristic of the steady state,the transient characteristic,the line selection based on the harmonic characteristic,and injection “S signal” based on the characteristic wavelet transform.It is determined that the zero sequence current ratio can be combined with the wavelet transform energy method,which made up for the shortcomings of each other,initially set as a more reasonable line selection method.Finally,based on the definition and realization of feeder automation,the basic remote control mode and local control mode,fault location model based on feeder automation is discussed.Based on the Matlab simulation platform,the simulation system of the actual power network parameters and structure in Xing Tai distribution network is established.An integrated line selection method based on zero sequence current ratio method and wavelet transform energy method is raised.The simulation results show that the method can accurately detect the fault location at the feeder and isolate it in time.Compared with the traditional method of “intermission method”,the method of fault detection in Xing Tai distribution network has some advantages.