Simulation And Research On Air Braking System Of EMU(Electric Multiple Units)

As an important means to ensure the safe operation of trains,the braking system is still controlled by foreign countries.The emergence of numerical simulation technology solves the problems such as high cost of traditional tests and data dispersion.Therefore,accurate analysis,evaluation and simulation of the principle and working process of key components,as well as further research and development design of independent equipment has become an urgent issue in the field of braking in China.This article takes CRH3 EMU braking system as the research object,based on AMESim,the brake system is modeled and analyzed,and combined with different working conditions and test bench data for inspection and correction.Secondly,the simulation modeling and leak test design of the standby braking system are carried out for the fault of the straight-through braking system.The main contents are as follows:(1)The development history of braking technology and braking numerical simulation of emu at home and abroad is collected,and the future development trend is summarized.The braking control system of emu and its working principle under braking function are introduced and analyzed in detail.(2)Preliminary modeling and characteristic analysis of the main components of BCU were carried out by using AMESim software.After the simulation of common braking and emergency braking,it was proved that the system could output precontrol pressure efficiently and accurately.Then the load parameters and control strategy are introduced,and the parameters are improved according to different working conditions.Finally,it is found that it can simulate the common braking and emergency braking of level 8 well,and can meet the practical requirements of engineering.(3)The brake test bench was built.Finally,the PID value of EP valve was determined to be 1,0.04,0.005,and the response frequency of electromagnetic valve was 150 Hz.The spring preload force of the air weight valve is 3902.1n and the lever ratio is 5.3:3.1.The air supply opening area of the relay valve is 2mm~2 and the exhaust opening area is 4.5mm~2.(4)The paper analyzes the standby braking system,and designs a simple detection device for leak detection.In order to verify its feasibility,it is modeled and analyzed,and the device is determined to be relatively reliable by referring to the evaluation criteria.