Analysis And Verification Of Heavy Load Train Traction And Dynamic Braking Model

With the development of train speed and heavy haul,it is inevitable that the longitudinal impulse will increase.At present,in the study of the mechanism of the longitudinal impulse generation and the optimization of the operation of the train,the common method is to carry out the field tests on the train running process of the target line,but the practice of the measured data not only consumes a lot of manpower and material resources,but also is poor in the generality of the results.Therefore,it is of positive significance to optimize the locomotive operation mode and reduce the longitudinal impulse by establishing the train model and adopting the method of simulation analysis.Through the establishment of the train running resistance model,the HXD1 and the SS4B locomotive traction and dynamic braking models,the combined simulation system of the train air braking and the longitudinal dynamics is perfected.In order to verify the reliability of the heavy load train running resistance model、traction and dynamic braking models,the parameters of HXDi and SS4B heavy haul trains in Shenshuo or Shuhuang lines were simulated and analyzed with the speed and the coupler force under different marshalling,traction and dynamic braking conditions.The results are as follows:first of all,for the heavy load combined train with initial speed in different range and HXD1 or SS4B respectively,the simulation of idle running is carried out and compared with the test,the maximum error of speed is only 0.9km/h.Secondly,whether HXDi(1+0)or(2+1+0)marshalling train,the maximum error of the simulation and test is within + 1km/h,and the maximum error ratio of the maximum coupler force of the fourth vehicles is 1.7%;The maximum error of simulation and test speed under downhill dynamic braking condition is less than 0.8km/h,and the maximum coupler force error ratio of the fourth vehicles is 3.7%.For SS4B electric locomotive,the maximum error of the simulation and test is less than 0.5km/h in the form of 2+2+0 or 2+0,and the maximum error ratio of the maximum coupler force between the fourth vehicles is less than 2%;The maximum speed error of simulation and test for downhill dynamic braking is 0.6km/h,and the maximum coupler force error ratio of fourth vehicles is 1.9%.It can be seen that the train running resistance model for the heavy haul train with different initial speed range in this paper can simulate the change of train instantaneous speed very well,and on this basis,the simulation results of the model simulation of HXD1 and SS4B heavy haul train traction and dynamic braking,such as speed,coupler force curve and fitting degree of test data,are also very high.It proves the feasibility of the method and the credibility of the model.The reliable model established in this paper will also provide strong support for further research on longitudinal dynamics of heavy haul trains.