Research On Electrical Parameters And Simulation Of Traction Power Supply System For High-speed Railway

Railway is an important national infrastructure,it's also the lifeblood of the national economy.In recent years,with the development of China's social economy and the promotion of the “The Belt and Road” strategy,the pace of construction of high-speed railways has been accelerated,and the technology related to high-speed railway is also constantly improved.High-speed railway has the characteristics of large traction load,high driving density and reliability requirements,which also puts higher requirements on high-speed railway related facilities and equipment.The traction power supply system is the only power source for high-speed railways,it plays a vital role in the safe operation of high-speed railway.Studying the electrical parameters and characteristics of the traction power supply of high-speed railway is of great significance for the safe and reliable operation of the traction power supply system and the analysis of the high-speed railway operation.In this paper,the high-speed railway full-parallel AT power supply mode as well as the composition and characteristics of the high-speed railway traction power supply system are studied.Besides,the structure of the AT traction network is analyzed.The mathematical model and modeling method of the traction power supply system are studied.Based on the theory of multi-conductor transmission line,the chain network model of full-parallel AT traction power supply is studied.The model construction method of longitudinal series element and lateral parallel element in chain network model is discussed.The calculation of wire impedance of different materials is derived.According to the four-infinite tunnel model,the distribution of the conductors in the tunnel is simplified,and the calculation method of the electrical parameters of the traction network under different geographical environments is analyzed.In order to solve the problem of large number of transmission wires and complicated calculation,the simplified method of multi-conductor transmission line model is analyzed.Different types of transmission wires are combined,and the combined electrical parameters calculation method of equivalent circuit is deduced.The traction power supply system model is built in matlab/simulink.According to the spatial distribution of the wires of the traction network,the appropriate coordinates are selected to determine the relative position and the basic parameters of different types of wires commonly used in high-speed rail.The program for calculating the electrical parameters of the traction network transmission line was compiled in this paper.The parameters such as distributed capacitance matrix,impedance matrix and admittance matrix of the traction network are calculated and extracted.According to the model,the voltage distribution of the traction network,the short-circuit impedance characteristics and the influence of the grounding wire on the rail potential are simulated.The typical TR short-circuit fault of the traction network was simulated.The experimental results verify the correctness of the model.The architecture,configuration and features of the DDRTS simulation platform are introduced.On the DDRTS real-time digital simulation platform,a fully parallel AT traction power supply system was built according to the actual line of the BeijingShenyang passenger dedicated line,and the short-circuit fault was simulated and simulated.The current distribution of the fault was verified by comparing with the actual short-circuit test data.The correctness and feasibility of the system have realized the application of the DDRTS real-time digital simulation system in the railway traction power supply system.It will lay a foundation for the closed-loop test and relay protection of high-speed railway power supply related equipment and equipment.