The Design And Simulation Research On Brake Control System Of EMUs

The high speed EMUs should have the capacity of stopping the whole train at a distance as short as possible when encountering an emergency. As one of the nine key technologies of EMUs, the braking ability of the brake system will affect the operation quality and safety of EMUs. Tests are the means of studying the braking problems of EMUs all the time. But tests, especially road test will occupy lines in operation and cost a lot of time and money. Most importantly, the results are greatly discrete. However, computer simulation technology can not only predict the performance of the system or cut down the design time, but also can analysis and evaluate the brake system, which can optimize system, shorten the design cycle and improve the stability of the system.This article takes the brake control system of high speed EMU as the reach subject. After learning the development situation of brake system inner and abroad, an approximately complete brake system with microcomputer control of electrical equipment, which contains a pneumatic control part and an electric control part, is designed referring to the braking control system of CRH Multiple Units. The pneumatic control part adopts direct electro-pneumatic brake with the electrical instruction computer.For the pneumatic control part, in order to study the influence of the relevant parameters to the performance of brake valves, a system which consists of EP valve, relay valve, emergency valve, empty-load valve, BFC/BFCF and so on is modeled and simulated by using AMESim in this article. In the simulation of studying on EP valve, a simulation model of a complete switch type EP valve is modeled with the method of using PID feedback control and pulse width modulation technology in AMESim. In the meantime, the control strategy of the EP valve is also designed.For the electric control part, the acquisition of brake instructions, the collection of braking state, the calculation and allocation of braking force and the delivery of brake instructions are studied in this article. Models of TBM, SBM, BCU, TCU and CCU and so on are built up using AMESim. The braking control strategy of service brake application and emergency brake application is designed based on the operating characteristics of high speed EMUs at the same time.Running state simulation model of EMUs is build up base on AMESim in this paper. This simulation model can simulate the braking process of the train, calculation and record the brake braking performance parameters and process data conveniently. At last, a complete braking control system of a whole train consisting of4M and4T is modeled based on AMESim. By simulating and calculating service brake application and emergency brake application in the situation of different initial speed and load, real time speed reduction and power distribution curve of the electro-pneumatic braking force under every braking level are obtained, which can clearly show the distribution situation of the real time speed reduction and the electro-pneumatic braking force under every braking level and speed. At last, emergency braking distance is calculated automatically using the simulating model. Also it is compared with the relevant provisions in order to show the rationality and science of the braking control system.