A Method For Calculating And Strengthening Capacity Of A Medium-Speed Maglev Line

With the accelerating process of urbanization in China,the traffic demand in the city circle has been greatly improved.The medium-speed maglev train with a speed of 200 km has the characteristics of fast,convenient and green,and it is a rail transit vehicle with broad application prospects.The line capacity is the key to the allocation of medium-speed maglev transportation resources.This article is based on the research results,combined with the characteristics of medium-speed maglev in the form of motor,power supply system and line system,researching on calculation and strengthening method of line capacity on medium-speed maglev.The main contents are as follows:(1)Define the concept of line capacity on medium-speed maglev,and analyze the main factors affecting the capacity of medium-speed maglev.Firstly,the definition of line capacity on medium-speed maglev is defined.Secondly,by comparing the differences between the medium speed maglev system and the wheel rail system,the main factors that affect the capacity of medium speed maglev line are analyzed,including power supply zone,auxiliary parking area and so on.(2)Establish a calculation model of line capacity on medium speed maglev.Considering the occupancy characteristics of train resources in the power supply zone when the train runs on the line,applying the idea of drawing train diagram,mapping power supply zone to arc and the train path to arc set,and the actual and virtual arcs represent the selection and occupancy of the train's running path.On this basis,a calculation model of line capacity on medium-speed maglev with minimum train running time is constructed.(3)Establish a strengthening model of line capacity on medium-speed maglev based on the optimization of power supply zones.First,the influence of the length of power supply zone on the time interval of power supply for train occupancy is discussed.Then,a strengthening model of line capacity on medium-speed maglev based on optimization of power supply zones is constructed,and through optimizing the length of power supply zones to improve line capacity.Secondly,the construction cost of power supply zone is considered.The optimization settings of power supply zones are analyzed from two aspects:improving the capacity of line and reducing the construction cost of power supply zones.(4)A method for solving the calculating and strengthening model of line capacity on medium-speed maglev is proposed.Firstly,the characteristics of medium-speed maglev capacity calculation and strengthening model are analyzed,combining with the characteristics of the two models,Lagrangian Relaxation Algorithm and Genetic Algorithm are used to solve the model respectively,and the basic principles and solving process of the two algorithms are introduced in detail.(5)An example is given to illustrate the validity and correctness of the calculation and strengthening model of line capacity on medium-speed maglev.Firstly,the correctness of the calculation model of line capacity on medium speed maglev is verified by CPLEX software.Secondly,combining with large-scale examples,the effectiveness of strengthening model of line capacity on medium-speed maglev is verified.The result shows that,when the construction cost of power supply zone is not considered,through optimizing the length of power supply zone,the line capacity of medium-speed maglev can be improved.In addition,design 3 cost scenarios for power supply zone construction,it is used to analyze the changes in the line capacity and the setting plan of power supply zone after adding the cost weight of the power supply zone.The result shows that,with the increase of cost weight in the model,the number of power supply zones is reduced,and the line capacity is also reduced.