Research And Design Of Rail Traffic Traction Power Supply System DC Bus Bar Protection

As an important part of urban railway system, security and reliability of the DC railway power supply system is the basis for the entire urban railway system. DC railway protection system is the key for the DC railway power supply system's security and reliability. Therefore, it is important to research and develop the DC railway protection system.The DC railway power supply system is one of the most important parts of urban railway system, and it is the basis for analysing system operation and fault scenario to model the DC railway power supply system. By studying the characteristics and configuration of DC railway power supply system, this paper presents a model of the whole DC railway power supply system based on Matlab/Simulink, including traction substation rectifier system, rail system and locomotive electrical driving system. With the previous model, this paper analyses the operation condition of DC railway power supply system and the locomotive.By analysing current distribution of the bus bar of different feeding arrangement, this paper proposed a new approach with the purpose of protecting the bus bar, then studied some interference factors such as measuring methods of the DC current, CT cable fault and harmonics of the system, and found the ways to reduce or eliminate these interference factors. At last, the bus bar protection algorithm was programmed based on Matlab/Simulink, and proved with simulation models and recording data of Beijing DC railway system.Based on the development trend of the DC traction power system, this paper designed the basic structure of the microcomputer protection system, and then deployed the protection system configuration. This paper also researched the communication system of protection device.The simulation models in this paper were modeled to coincide with the actual situation. the simulation results of different scenarios proved the effectiveness of the bus bar protection algorithm designed in this paper. This paper also researched the protection system configuration and the data communication mode. All of above provides theoretical and experimental basis for the practical applications of DC bus bar protection device.