Optimal Energy Speed Profile of Medium-Speed Maglev Trains Integrating the Power Supply System and Train Control System

Abstract

As a new type of transportation serving the suburban passengers, the medium-speed maglev (MSM) is gradually becoming the focus of scholars. This paper addressess the speed profile optimization problem for MSM train operations by integrating the power supply system and train control system under various constraints. Unlike the model for optimizing the mechanical energy of the train, this approach aims at the lowest energy consumption of the substation for the MSM system. First, a speed profile optimization model for the MSM train is built by combining the mathematical control model of the long stator synchronous linear motor and dynamic equation of train, in which the stator current is the control variable. Next, a dedicated dynamic programming approach is proposed to solve the optimization model. The results of the numerical experiments show that the proposed model outperforms the model that only considers the train mechanical energy, and the energy consumption is reduced by 10.3% and 6.5% in the two case studies, respectively. Furthermore, the relationship between energy consumption and travel time is analyzed to reflect the optimal results of the proposed model limited to different fixed travel time.

Energy‐efficient train timetabling for a medium‐speed maglev line considering propulsion and suspension energy consumption

“…The problem is then solved using dynamic programming and mixed-integer linear programming (MILP) approaches that make use of these characteristics. Additionally, Lai et al [49] considered the energy consumption of the substation for the MSM system and proposed a speed profile optimization model for the MSM train, which is constructed by merging the mathematical control model of the long-stator synchronous linear motor with the dynamic equation.…”

“…The discretization process of the train segment running time and train load rate is shown in Figure 4. Furthermore, in the yth segment, if the train segment running time and train mass are known, we can use the TSPO method from Lai et al [49] to calculate the optimal energy-saving train speed profile of the maglev. At the same time, we can also obtain a series of energy consumption, that is, {E y,i,1 , E y,i,2 , …}.…”

“…On the other hand, since conflict detection of multiple trains needs to be based on the train's operating speed profile, the current results cannot verify that the train operation meets the safety requirements. In this section, we generate the train operation strategy with reference to Lai et al [49], including the train operation speed curve and the traction power supply curve of the traction substation. In the MSM system, only one train can run in one power supply partition at the same time [49].…”

“…In this section, we generate the train operation strategy with reference to Lai et al [49], including the train operation speed curve and the traction power supply curve of the traction substation. In the MSM system, only one train can run in one power supply partition at the same time [49]. We calculate the block time (the method details can be found in Pachl [55]) of the MSM train, which can be used to detect if there is a conflict between two trains.…”

“…Since there is no commercially operated MSM line, an MSM simulation line was used. The basic information on vehicles and lines is derived from Lai et al [49], CRRC Tangshan Co., Ltd., and a real suburban line (including slope, maximum speed limit etc.). The line is a bi-directional line with six stations, and the total length is 58.7 km.…”