Modeling For Metro Locomotive And Analysis Of Fault Condition Of DC Traction Power Supply System

ABSTRACT:Urban rail transit is the focus of urban public transport development, Security and reliability of the DC railway system operation is the basis for entire urban railway system. The DC railway protection system mainly imported from foreign countries. Therefore, it is necessary to research and study on the configuration and characteristics of DC railway power supply system and the fault of the DC railway system in order to analyze system operation of the DC railway system.Firstly, this paper conducted a research on the characteristic as well as the constituent of Beijing urban 750V DC traction power supply system, analyzed the AC locomotive drive system emphatically, and obtained the locomotive operating control strategy chart then analyzed the locomotive brake operating mode with emphasis. With a line vehicle's actual parameters this paper conducted a detail traction calculation, drawn up the traction characteristic and the brake characteristic curve.Then, this paper built a model of the DC750V traction power supply system in Matlab/Simulink, including traction power system, locomotive drive system and the metro rail system Because frequent starting, accelerate and brake in its run process, it caused the power supply system electricity parameter's frequent change. Based on the slip frequency vector control, this paper carried on the simulation of metro locomotive starting, over three-track radio zone, regenerative braking condition on the impact of DC traction power system.Through the analysis of DC traction power system's fault mechanism and fault current, got to know when the failure point is different the feature of fault current, the current rise rate and the current increment is different. Short-circuit fault model simulation results show that the locomotive starting current is similar to the remote short-circuit current will affect the DC line protection.The paper discussed the DC traction power supply system's feeder protection configuration in the end, and detailed analysis the principle of protection based on the current amount. The entire model's build to study the protection installation and its coordination has provided the theory basis and the experimental model foundation.