Fault Location In Multi-Branch Distribution Network Based On The First Traveling Wave Time Difference Of Arrival Relationship

The distribution network connects the transmission network and users,which plays an extremely important role in the power system.When the distribution network fault,it will lead to huge economic loss due to the interruption of power supply.With the development of science and technology,distance measurement technology based on traveling wave has become a new research hotspot.But the technology of traveling wave fault location for multi-branch distribution network is not mature.In order to solve the application problem of traveling wave method in distribution network,this paper presents a new traveling wave fault location method suitable for multi-branches distribution network based on the time difference relationship of first traveling wave as the research object.This paper studies the basic theory of traveling wave,and analyzes the generation,propagation,refraction and reflection of traveling wave;The effects of transition resistance,number of branches,line parameters,propagation distance and intermittent fault on the first traveling wave were analyzed;The effects of traveling wave speed,sampling frequency,double-ended data synchronization and overhead line combined with cable on the accuracy of traveling wave fault location is analyzed.Wavelet transform is the most effective mathematical tool to analyze traveling wave at present.Through the theoretical analysis of wavelet transform and wavelet modulus maximum,the specific method to extract the arrival time of traveling wave is determined,and the effect of wavelet transform analysis is verified by simulation.Based on the analysis of the first traveling wave time difference,a network fault location algorithm based on the first traveling wave time difference is proposed.The algorithm is implemented by obtaining the judgment matrix from constructing characteristic time difference matrix and real time difference matrix.Finally,the fault location is determined by analyzing the fault judgement matrix.A large number of simulation results show that the algorithm is applicable to different fault types,different fault locations,different transition resistances,intermittent faults and have high precision...