Research On Effect Of Adhesion Control On Train Dynamic Performance

With the rapid development of economy,the task of freight transportation is becoming more and more arduous.Heavy-haul railway transportation,as a mode of transportation with large volume and high efficiency,has attracted attention from more and more countries.China is no exception.Ten thousand tons of Heavy-haul trains have been operated on Daqin,Shuohuang and Shanxi-Henan-Shandong railway lines successively.Due to the large total weight and heavy running resistance,heavy-haul trains usually necessary to use one or more high-power locomotives with good traction performance,and the factors that limit the traction performance of the locomotive mainly include the wheel-rail adhesion and neutral-section.For the former,the adhesion control is usually adopted,so that the locomotive can exert the maximum traction under the same rail surface condition.For the latter,it is necessary to shorten the length of the power-off coasting time when the locomotive passes through the neutral-section and to restore the traction force as quickly as possible after passing,so as to improve the train passage efficiency.However,the traction change has a significant impact on the safety performance of the train.Therefore,the influence of the adhesion control and the recovery rate of the traction force on the longitudinal impact of the train and the running stability of the locomotive is studied in this thesis.Firstly,the principle of locomotive adhesion control and the research status of adhesion control and longitudinal dynamics of trains at home and abroad are introduced in this thesis.Based on the adhesion control theory and the train longitudinal dynamics theory,the adhesion control system,air brake system,draft gear model and vehicle dynamics model are established in MATLAB/Simulink.The influence of main parameters of air brake system on the boost characteristics of brake cylinder is analyzed.In order to better simulate the wheel/rail creep characteristics of locomotive,a locomotive multi-body dynamic model was established in SIMPACK based on the vehicle system dynamics theory.MATLAB/Simulink and SIMPACK co-simulation method was used to jointly build a 10,000-ton heavy-duty train simulation platform,and the real-time data exchanged through SIMAT function.Based on the simulation platform.this paper first analyzes the influence of the adhesion control on the locomotive adhesion utilization and the longitudinal dynamic performance of the train when the train is driven by different traction forces under different rail conditions.The results show that when starting under poor rail conditions,the load rate should be relatively small when there is no adhesion control;when adhesion control exists,it should be loaded at a relatively fast loading rate,and the traction force can rise rapidly to its maximum value,which can be adjusted by the adhesion control system to keep it as close as possible to the maximum allowed by the current rail conditionsSecondly,the influence of adhesion control on the cyclic braking performance of trains on 12 ‰ downhill with speed limited of 80 km/h is analyzed.The results show that in the process of cyclic braking,the adhesion control can make the locomotive maintain a large electric braking force for a long time without applying air braking force,so as to improve the air braking and mitigation speed of the freight car and reduce the wear of the locomotive brake shoe.The speed at which the train starts air braking and mitigation during non-adhesive control shall not exceed 78.3 km/h and 54.4 km/h,respectively,and may increase to 79.0 km/h and 60.8 km/h when there is adhesion control,effectively improving train operation speed.The adhesion control has no obvious influence on the maximum value of the coupler force in the cyclic brake.Finally,the influence of the recovery rate of locomotive traction force on the longitudinal dynamic performance of trains after passing through the neutral-section with different devices is analyzed.The results show that the locomotive can be restored at a rate of 200 kN/s after passing through the neutral-section by using the electronic phase passing device,which can reduce the coupler force and improve the locomotive running stability.After using the traditional over-phase device to coasting through the 1300 m long neutral-section,the smaller locomotive traction recovery rate can effectively reduce the train coupler force and improve the running stability of the locomotive.