Optimization Of Electro-pneumatic Braking Distribution For High Speed Train

At present, power-distributed method is the development trend of the dynamic configuration mode of high speed train(HST). The power-distributed structure has obvious advantages in speed promotion, energy saving, environmental protection and other aspects, for which power-distributed structure has been adopted in Chinese high-speed trains. The high-speed operation of HST puts forward high requirements on the train braking ability; and the operation safety of HST. Therefore, this paper proposes the optimization strategies of the braking speed classification control model and the braking force distribution control model to improve the safety of train operation, and achieve targets of efficient braking,energy saving and emission reduction.By referring to the speed hierarchical control method of Japanese Shinkansen, we analyze the existing deceleration performance curve. By selecting the appropriate adhesive characteristic curve, the braking process is handled in a reasonable speed hierarchy when taking the limitation of adhesion and the comfort of passengers as the constraints, and thus we can obtain the optimized deceleration performance curve. The braking distance is reduced, the braking time is shortened, and the braking efficiency is improved by using the obtained deceleration performance curve.Considering one motor car and one trailer as a braking unit, the new braking distribution model can distribute braking force reasonably between motor vehicle and trail vehicle. In engineering practice, the regenerative braking force and the pneumatic braking force of motor vehicle and trail vehicle are not uniformly distributed. To solve this problem, we propose a new braking distribution model on the basis of the existing braking distribution model of electro pneumatic braking control system. Compared with the previous methods, the new braking distribution model can increase braking efficiency and reduce the wear of train brake shoes, so as to ensure the safety operation of trains. Because regenerative braking has the advantage of high energy utilization rate and no mechanical wear, the implement of regenerative braking is prior to the friction braking in the braking unit.Three braking conditions, such as full service braking, prompt braking and emergency braking, are simulated by using MATLAB. Then, we compare the braking performance under different deceleration performance curve. By using different braking distribution model, the braking force distribution results of braking unit and the brake cylinder pressure variation of motor vehicle and trailer vehicle are computed and simulated. The simulation results show that the optimization of the braking process can improve the braking efficiency indeed. And to improve the safety operation index, we also analyze the coordinated optimization strategy of electro pneumatic braking under which kind of model can effectively balance the braking force distribution, and the wear of equilibrium wheel and brake shoe and improve the safety operation index.