Research On Short Circuit Fault Diagnosis Of Urban Rail Transit Power Cable

In recent years,urban rail transit has developed rapidly with the development of industrial technology.With the increase of urbanization rate,the congestion phenomenon is prominent.In order to improve this phenomenon,many big cities in our country increase the investment of urban public transportation.Urban rail transit power system is the guarantee for the normal operation of rail transit trains.The safety of urban rail transit power system has gradually become the focus of attention in rail transit industry.Therefore,the fault diagnosis of power cable short circuit in power supply system becomes a hot topic in this field.At present,the diagnosis of power cable short circuit fault in the power supply system of Chongqing rail transit mainly relies on manual work,but the fault finding efficiency is low.Aiming at the deficiency of short circuit fault diagnosis of power cable in Chongqing rail transit power supply system,the work done in this paper is as follows:Firstly the types and causes of short circuit fault of urban rail transit power cable are analyzed.By referring to relevant data,the paper classifies and compares the faults of the power cables in the power supply system of urban rail transit,and analyzes that the probability of short-circuit fault of the power cables in urban rail transit is the largest.The electrical module in Matlab software is used to establish the simulation model.This paper conducts simulation experiments on various short-circuit faults of urban rail transit power cables,studies and analyzes the current and voltage waveforms when short-circuit faults occur in Chongqing rail transit power cables,and provides theoretical basis for the subsequent identification of power cable short-circuit faults.Secondly Matlab software is used to establish a simulation model,set up different types of short circuit faults of Chongqing rail transit power cable,and obtain800 groups of transient voltage waveform when Chongqing rail transit short circuit fault.In this paper,the modal decomposition method is used to decompose and reconstruct the short circuit fault signal of power cable in Chongqing rail transit.The energy entropy values of each frequency band were calculated by using the information entropy theory,and the feature vectors under different short-circuit faults were constructed,which provided data support for the short-circuit fault diagnosis model of power cable of Chongqing rail transit.Finally a short-circuit fault diagnosis model of urban rail transit power cable was established based on Hopfield and RBF multiple neural networks,and 800 groups of fault feature vectors were used for network training and testing.The voltage signal of short circuit fault of power cable of Chongqing rail transit is decomposed and reconstructed by mode decomposition method.Based on the information entropy theory,the energy entropy of each frequency band is calculated,and the feature vector of short circuit fault of power cable in Chongqing rail transit is constructed.By comparing the diagnosis algorithm of short circuit fault type of urban rail transit power cable,the superiority and effectiveness of using multiple neural networks for short circuit fault type diagnosis of urban rail transit power cable are further illustrated.