Research On Fault Location Of Transmission Line Based On Wavelet Transform

The most frequently faulty component in a power system is a transmission line,which can cause huge losses to users and power systems.The rapid detection and repair of the fault point after a short-circuit fault on the line ensures that the grid is safely and reliably powered.With the development of the power grid,the number of transmission networks has also increased dramatically.As the complexity of the grid structure is higher,the failure rate of transmission lines is increasing.The fault location problem of transmission lines has attracted more and more attention from experts and scholars.At present,the impedance method and traveling wave method are mainly used to study the positioning of transmission lines.Aiming at the problem of dispersion caused by traveling wave propagation in hybrid distribution network,the wavelet transform is used to decompose the traveling wave into a number of non-overlapping narrow frequency bands to reconstruct the traveling wave on a specific narrow frequency band,so as to more accurately calibrate.Each modulus wave head arrives at the moment.Using the traveling wave method,the db4 wavelet 5 layer decomposition method is used to analyze the fault location of the transmission line.According to the actual situation of grid operation,the MATLAB/SIMULINK simulation software is used to establish the fault system model of the transmission system of the model power system.The established simulation model is used to analyze the characteristics of each electrical quantity when various faults occur in the transmission line,and the variation law of the electrical quantity at various faults is obtained.Under the condition that the traveling wave propagation speed is determined,the traveling wave information at the fault point is calculated,and the extracted traveling wave information is reflected and reflected to the transmission time required by the detecting point,thereby calculating and determining the distance of the fault point from the detecting point.The wavelet packet of MATLAB is used to perform thetraveling wave extraction and the traveling wave decomposition and reconstruction of the extracted information at the fault point,and the distance between the fault point and the monitoring point is calculated,so as to realize the ranging location of the fault point based on the traveling wave method.The feasibility and accuracy of the method for fault location are tested by the results of simulation analysis.