Research On Comprehensive Optimization Of EMU Operation And EMU Depots Location Selection

With the rapid development of high-speed railway in China,the high-speed railway network has been formed,and the characteristics of EMU network operation has been becoming more and more obvious,which needs higher requirements for the preparation of EMU application plan.In addition,the operating mileage of high-speed railways and the number of EMUs are still growing,and the demand for maintenance of EMUs is increasing.However,the maintenance capabilities that current EMU depots can provide are close to saturation.Therefore,it is particularly important to study how to increase the maintenance capacity and improve the utilization rate of EMUs.Aiming at this problem,we conducted the research and analysis from the perspective of the comprehensive optimization of the EMU application and the location selection of the EMU depots.The research was carried out mainly from the following aspects:(1)The analysis of the basic theory of EMU use and optimization problem.First of all,we described the basic theory of the use of EMUs,including relevant knowledge of EMUs' use plan and maintenance plan.Then,the influencing factors of the use of EMUs and the preparation of maintenance plans were analyzed.In this part,we highlighted the distribution and construction of Chinese EMU depots and their maintenance capabilities.Finally,we proposed to transform the location selection problem and EMU operation problem into location-routing problem for analysis as our research idea for the optimization of EMU application.(2)Model construction of comprehensive optimization of EMU operation and location selection of EMU depots.Firstly,we introduced the spatiotemporal state network system to describe the various processes of EMU application,and converted EMU application problems into network problems.Next,taking the minimum total connection time and the minimum maintenance cost as the dual objectives,we constructed a comprehensive optimization model for the use of EMUs and the location of EMUs after considering demand constraints,overhaul repair schedule constraints,continuation constraints,overhaul capability constraints and EMU construction funding constraints.(3)The Solution and Verification of the Comprehensive Optimization Model of EMU Operation and EMU depot Location Selection.First,according to the idea of two-stage solution,the model was processed based on the Lagrange relaxation method,and the decomposition was transformed into a location problem and a VRP problem.Second,we designed algorithms to solve the two problems separately,used the Lagrange relaxation algorithm to combine the two problems,and used the upper and lower bound alternating iteration method to solve the problem.In addition,we used a small case to verify and solve the EMU application problem.Finally,we set the operation map data in Shanghai Bureau as an example to solve the comprehensive optimization problem of the EMU application and the location of the EMU depots selection,which verified the feasibility and rationality of the model algorithm.The analysis of the research case shows that the content of this study has a good guiding significance for improving the maintenance ability and utilization rate of the EMU.