Research On Cable Fault Location Based On Wavelet Analysis And Traveling Wave Combination

Choosing power cable for power supply is both safe and reliable, still beautifying urban layout. With the rapid economic development of our country's process, power cable in urban power system are already applied very extensive. Due to the cable operation time and using quantity of power cables increasing gradually, power cable fault occurred frequently, bringing losses to using electric unit and the vast majority of users. Therefore, there is very important significance to detect power cable faults fast and accurately, determine the fault location and ensure the users' electricity quality.This paper uses fault location technology based on wavelet transform, introduces wavelet transform method, multilayer wavelet decompose the collected fault signal, and then use wavelet transform to filtrate the signal and detect signal singularity. To find out the singularity of the high coefficients of fault signal, the paper adopts the method of searching modulus maxima and realizes the precise rangefinder fault. Through the simulation platform of MATLAB, the paper establishes the power cable fault system simulation model and obtains the cable faults fluctuations in the end. And using the proposed location algorithm to process the obtained simulation waveform, the feasibility and accuracy of this method was verified. At the same time the paper puts forward and develops a kind range finder formula not limited by wave velocity. That makes the calculation of the fault distance to dispense the affect from wave velocity theoreticallyAt the same time the paper evaluates the reliability and accuracy of traveling wave fault location method based on D-type double ending and A-type single ending comprehensively. Based on this, the paper puts forward the principle of combining and optimizing these two kinds of traveling wave measurement program, and the principle is successfully applied in practical fault transient traveling wave analysis. Compared with the single type D or type A traveling wave solutions, the advantage of the rangefinder scheme is to use type A rangefinder method to verify and correct the ranging results obtained by D-type ranging method for improving the ranging accuracy and dependability. The site application examples also indicates that the traveling wave optimized combination measurement program is feasible .Compared with the previous ranging method, the accuracy is improved obviously.A lot of simulation data and site application examples show that the proposed ranging method based on wavelet ranging method and traveling wave optimized combination can realize the location of the power cable fault fast and accurately. The research on theory simulation and practical application provides a strong theoretical support and technical guidance for cable fault location work.