Research On Energy Saving Slope Optimization Model And Algorithm Of Intercity Railway Under Combined Operation Of Sprinter And Express Train

How to scientifically design the rail transit line profile is one of the key issues in the design of intercity railway.Reasonable setting of the profile at the initial stage of construction can effectively improve the energy-saving effect of train operation,which is of great significance to the management of rail transit operations.Existing studies on the design of energy-saving slopes mostly focused on traditional subways,while there are few studies on the design of energy-saving slopes on intercity railway with high-speed,long-range,and overtaking-operation.This paper studies the optimization of the energy-saving slope of the intercity railway in order to provide feasible theoretical and methodological support for the design of the energy-saving slope of the intercity railway.The main work of the paper is as follows:In view of the particularity of the intercity railway,the running speed,section length,and operating organization of the normal subway are compared.And the influence factors of the energy-saving slope design of the intercity railway are analyzed.On this basis,the force of the train is analyzed,and the conditions of the cruise and alternate strategy of the sprinter and express train are studied,and the expression function of the train operation energy consumption is constructed.Under the consideration of the variation of train running time,the optimization model of the energy saving slope of the intercity railway under the combined operation of sprinter and express trains is established.In order to obtain the optimal solution of the energy-saving slope optimization model,the Gauss pseudospectral method is introduced.According to the pseudospectral method solution process,the energy-saving slope optimization model is transformed into the optimal control problem description form.And the Gauss pseudospectral method is used to discretize the problem as a nonlinear programming problem,which is solved using a sequential quadratic programming algorithm.Finally,the solution result is obtained,and the applicability of Gauss pseudospectral method in the energy-saving slope optimization is summarized and analyzed.Considering the limitation of Gauss pseudospectral method,a genetic algorithm based on dynamic programming is designed to solve the model.Dynamic programming is used in the fitness function to realize the calculation of train operation energy consumption.At the same time,unfixed chromosome length can enhance the global search ability.According to the characteristics of the unfixed chromosome length,the cross operator and mutation operator are rewritten to complete the algorithm design.Guangzhou Line 18 is selected as the verification,and it is found that the Gauss pseudospectral results have the best energy-saving effect when solving the energy saving slope plan of the train cruising strategy among Gauss pseudospectral method,genetic algorithm based on dynamic programming and other methods;The whole line is selected to compare the original design scheme with the genetic algorithm based on dynamic programming.And it is found that the energy consumption of the algorithm scheme is 8.4% to 12.9% less than the original design energy consumption.It is found that the energy-saving slope design has the greatest impact on the energy consumption of the sprinter trains,and then cross-station speed limit express trains by sensitivity analysis of the combined operation of sprinter and express trains.It can indicate that reasonable energy-saving slope plan can effectively improve the energy-saving effect of sprinter trains and cross-station speed limit express trains.According to the analysis of the plan,the design recommendations of the energy-saving slope of the intercity railway are summarized.In summary,in view of the particularity of the intercity railway,this paper designs a solution algorithm based on Gauss pseudospectral method and a genetic algorithm based on dynamic programming to solve the energy-saving slope optimization model.Effective energy saving result is achieved after vitrification with the original scheme and other methods.According to the actual engineering case,feasible suggestions are concluded for the design of the energy-saving slope of the intercity railway.