Simulation Research On Fault And Relay Protection System Of High-speed Railway Traction Power Supply System

Due to the high reliability and high safety operation requirements of high-speed railways,there are many differences between the high-speed railways and general speed railways,especially in traction power supply.After the operation of the high-speed railway,the electrical characteristics and status of the traction power supply system during its operation are quite different from that of the general speed railway.Therefore,carrying out the simulation calculation and analysis for the traction power supply system of the high-speed railway is very necessary to probe deeply into the various problems that arise in the operation of the high-speed railway power supply system.The dissertation," Simulation Research on Fault and Relay Protection System of High-speed Railway Traction Power Supply System" is a sub-topic of " Research and Development of operation simulation system in High-speed Railway Traction Power Supply".Through the establishment of full parallel AT traction power supply system fault simulation model we could simulate various kinds of short-circuit fault,and we also have done simulation research on relay protection system of traction power supply system and fault location device.This dissertation first analyzes the power supply mode and principle of full parallel AT traction power supply system.Taking the traction power supply system of Dengjiashan Chang-Kun high-speed rail as a simulation object,the fault simulation model of full parallel AT traction power supply system has been built based on PSCAD/EMTDC electromagnetic transient simulation software.The model can simulate various kinds of short-circuit faults in high and low voltage side of busbar,power supply line,traction network,and various kinds of short-circuit faults in AT and substation.The comparison between simulation data of fault simulation model and actual fault data shows that the fault simulation model can accurately simulate all kinds of short-circuit faults in traction power supply system.At the same time,the simulation model can generate fault simulation data files for simulation of relay protection to simulate the sampling process.Furthermore,the simulation of high speed railway relay protection system has been carried out.The relay protection simulation program was writed based on VC++ 6.0,the emulated functions include;sampling and filtering of fault current and voltage waveform,protection algorithm,logic judgment,action alarm and trip exit process,and it can operate protection value and generate fault reports.Based on field measured relay protection action data,the operation of the relay protection simulation program and the operation of the field protection device in the event of a short-circuit fault has been compared.The conclusion is that the two are completely consistent.This verified the accuracy of the relay protection simulation program and provided the basis for troubleshooting for the project " Research and Development of operation simulation system in High-speed Rail'way Traction Power Supply".Finally,the simulation of the high-speed railway fault location device has been done.It can provide suitable methods for different operating modes of the system under a variety of short-circuit fault automatically.At the same time,we have developed a high-speed railway fault location simulation software for the site.The simulation results have been compared with the calculation results of the electrified railway fault distance measuring device.The error of the simulation software based on different distance measurement methods was smaller.This data can provide a reference for the technicians and help to find the fault location accurately.