Study On ECP Braking Strategy Of Heavy Haul Train

With the rapid development of China’s economy, the transportation demand of goods and passengers is growing with each passing day which brings great pressure to our country railway transportation. The main problem of China’s railway transportation is the railway transport capacity can’t meet the increasing traffic demand. The development of heavy haul transport has become a main way to improve the current railway transport capacity. But the air brake system of train with lengthening marshalling, affected by the air brake signal propagation velocity in the braking process, will produce the overall braking train uneven phenomenon, leading to train longitudinal impulse level is too large, and cycle braking force decay.In this paper, by the means of simulation analysis effects of air brake system for heavy haul train brake synchronism. Obtain that with the air velocity limit, train braking process is difficult to achieve complete synchronization action, Increase the length marshalling will increase train asynchrony and the vehicle braking force train distribution will not uniform, effect train braking distance and increasing train longitudinal impulse. Facing the traditional air brake problems this paper study the international freight transportation widely used ECP (electrically controlled pneumatic brake) technology. The ECP control technology use of electric signal as brake signal, breaking the air wave velocity limit, raising the train brake synchrony, shortening the train braking distance, effectively reducing the brake longitudinal impulse level. In this paper, by using the simulation methods, simulates braking characteristics of ECP control.This paper analyzes the influence of train pipe pressure gradient, the ECP brake technology ECP equipment response speed and coupler clearance and other factors on the train longitudinal impulse. When the train pipe pressure gradient exists,10000t trains will have a greater impact in the end, the maximum coupler force of20000t trains is squeeze pressure. The longitudinal impulse train pipe pressure gradient increases will increase the train, and is proportional to the length of train. Increased vehicle structure gap will affect the train longitudinal impact force.This paper simulates the braking ramp in complex line heavy haul train, Analysis of air brake braking position of the most dangerous. When the train is in the concave slope variable slope near the point, i.e. flat add uphill and downhill add flat do emergency brake will produce bigger coupler pressure. When the train around2/5location in the turning point, is the most dangerous of the emergency brake starting position. Summed up the ramp longitudinal impulse effects on the train, the train longitudinal impulse in the turning point is mainly affected by two factors of braking asynchrony and ramp slopes. Calculate the train longitudinal impulse of ECP control brake technology level.The principle of weakening of the ramp vehicle braking force is increasing the flat part of the vehicle braking principle and weakening the longitudinal impulse level at slope changing points near the train emergency braking.