Research On Fault Diagnosis Of High Speed Railway Power Distribution System And Fault Location Of Continuous Line

In recent years,China’s high-speed railway has been developing rapidly.The power distribution system supplies power to high-speed railway station and all the non-traction electrical loads along the continuous line,which is the only power supply for the railway signal system,and it is related to the normal operation of high-speed railway,so higher requirements should be put forward for the reliability of power supply.At present,the development level of high-speed railway power distribution system is different,and its fault diagnosis and fault location methods are traditional,which is still far from the grand blueprint proposed by China State Railway Group Co.Ltd for the development of intelligent high-speed railway.Based on the actual development demand of the current high-speed railway,this paper analyzes and summarizes the shortcomings of the existing high-speed railway power distribution system through investigation and research.By referring to the intelligent fault diagnosis method proposed in the development of power grid and fault location method of high-voltage transmission line,this paper provides a comprehensive fault diagnosis and fault location method for high-speed railway power distribution system.In this paper,the overall architecture of high-speed railway power distribution system is firstly constructed,and Xicheng high-speed railway is taken as an example,the actual electrical main wiring structure and relay protection input mode of Jianmenguan 10 k V power distribution station are analyzed.According to the actual operation condition of the comprehensive continuous line from Guangyuan to Jianmenguan pass section,the simulation model of high speed railway power continuous line between two power distribution stations on the Matlab/Simulink simulation platform is built.The characteristics and operation parameters of each component of the model are introduced in detail and the running condition of continuous line is analyzed.In order to determine fault components of high-speed railway power distribution system,a fault diagnosis method based on bayesian network model is studied in this paper.According to the actual electrical wiring of the high-speed railway power distribution station and combined with the relay protection configuration,key electrical components such as bus,transformers and transmission lines were extracted to construct the bayesian network model based on the fault electrical components.Through practical examples,the fault probability of each component in the bayesian network fault model was calculated by reasoning on the Ge NIe Modeler platform,the fault components were analyzed and determined,and the correctness of the model and algorithm was verified.In this paper,a fault type identification method based on wavelet transform to obtain the maximum value of fault current module component is studied.The fault boundary conditions of the continuous line under various fault conditions are studied,and the characteristic criterion of mode fault component of various fault conditions is derived by phase mode transformation.Simulation experiments under different fault distances,fault grounding resistance and fault initial phase angles were carried out on the simulation model of high-speed railway power continuous line.The fault type recognition criterion is verified and corrected by analyzing simulation data.In order to determine the fault location of the continuous line,a fault section location method through the improvement of continuous line cable branch box is designed in this paper,and the method can only locate the continuous line fault in the section close to 3km.In order to realize the precise location of continuous line fault,a fault locating method of power continuous line based on D type travelling wave fault ranging method is studied.This paper fisrt compares and analyzes the principle and characteristics of A type and D type travelling wave fault ranging method,and the possible range error caused by the D type travelling wave fault ranging method is studied.Wavelet transform(WT),Hilbert-Huang transform(HHT)and variational modal decomposition combines with Teager energy operator(VMD+TEO)are used to detect and extract the traveling wave signals.On the Matlab/Simulink platform,the effectiveness of the three methods for fault location was verified.In addition,it makes a comparative analysis on ranging accuracy,fault type,applicability of transition resistance and anti-noise ability.The results show that the three methods can accurately locate the fault of the continuous line.The D type travelling wave fault location method based on VMD+TEO still maintains high ranging accuracy in the noise environment,which is the preferred method for fault ranging of high-speed railway continuous line.