Research On Power Cable Fault Detection Technology Based On Wavelet Analysis

In the transformation of national urban power grids and rural power grids,power cables are widely used in medium and low-voltage power distribution systems due to their small footprint,strong anti-interference performance,stable power supply,simple operation and low maintenance.The larger the cable diameter,the larger the capacitance,which in turn leads to an increase in the power factor of the power grid.However,due to safety and other considerations,power cables are generally used with high-hanging or deep-buried methods for power transmission,which makes it difficult to detect hidden perils in time when they occur.As a result,the detection of hidden perils not only takes enormous time and results in excessively long power outages,but also causes great obstruction to maintain normal living and production orders.Therefore,the detection of power cable faults makes significant sense to better guarantee the power consumption of residents and promote the economic development.With the development of science and technology and the progress of the times,the fault analysis and elimination of transmission lines has also entered the era of microcomputer operation.Although the protection of the relay system signal is still being carried out by means of Fourier,the wavelet analysis approach,with its rapid development in recent years,has shown its validity and availability in real power systems.This paper takes the location of power cable fault points as the research foundation,and uses wavelet transform and traveling wave distance measurement as the main research strategies to accurately locate power cable fault points.The thesis starts with the research on the basic electrical parameters of the cable electrical characteristics,introduces the traveling wave ranging analysis method,discusses the causes and transmission characteristics of the fault traveling wave,compares different traveling wave ranging methods,and selects the best method.For precise fault location,this paper selects the best D-type fault location method.Through multi-scale analysis and research on wavelet transform,several different threshold denoising methods are compared,and traditional denoising methods are compared,and the PSO denoising method is selected to denoise the fault traveling wave.This method uses lifting wavelet instead of traditional wavelet pair The noisy signal is decomposed,and a simple threshold optimization method is given to obtain effective traveling wave information.Finally,on the basis of SIMULINK,a simulation operation model of cable fault location was created,and wavelet was used for traveling wave signal processing,and the fault point was finally locked through effective signals,which achieved good results.Through the results of the calculation examples,it can be concluded that the PSO denoising method can effectively extract the fault signal,and it has obvious advantages compared with the traditional threshold denoising method.Further simulation studies have shown that the modulus maximum value and singular performance accurately grasp the traveling wave moment of failure and improve the efficiency of cable troubleshooting.