Research On Multi-Train Coordinated Energy Saving Optimization Based On Speed Profile Adjustment

With the increasing of urbanization and urban population,the traffic problem is getting worse.Owing to the advantages of high efficiency,large capacity and convenience,the urban rail transit has developed rapidly in China.However,the rapid development of urban rail transit is accompanied by a large increase in energy consumption Therefore,it is of great practical significance to study the optimization of energy utilization of urban rail transit.Regenerative braking energy which was generated during regenerated braking has a huge potential as the trains of urban rail transit traction and braking frequently.In order to realize the regenerative braking energy utilization by multi-train cooperation,this paper presents speed profile adjustment method,the advantage of this method is that it has no effect on the original timetable.Firstly,a train energy saving optimization model considering the utilization of regenerative braking energy is built.The model takes the energy achieved from power supply system as the optimal object and applies Pontryagin's Maximum Principle to analyze the train's optimal control theory.Combined with this theory,the dichotomy is used to solve the speed profile adjustment algorithm.When available regenerative braking energy 'occurs in train's coast or speed-hold case,the speed profile adjustment algorithm is simulated combined adjoint variable.Then an equivalent model of the bidirectional power supply network of subway system is established,including the models of the substations and the train traction motors.And the energy conservation of the train speed profile adjustment algorithm is verified,combined with the actual line information.Secondly,the algorithm of regenerative braking energy utilization in multi-train and multi-section based on speed profile adjustment is studied.First of all,the model of multi-train matching in multi-section is built,the influence of the difference between the braking time of the braking train and the acceleration time of the traction train on regenerative braking energy utilization based on speed profile adjustment algorithm is also studied.Then,the optimization model of multi-train regenerative braking energy utilization in multi-section based on speed profile adjustment algorithm is built,and select the actual line timetable information of 120 trains,12 operation-sections(3 power supply sections)in different periods(peak period/off-peak period),and verify the energy conservation of this algorithm.The simulation results show that the algorithm is more suitable for the peak time period of the timetable.Finally,in order to verify the energy conservation of speed profile adjustment algorithm in the actual system,the train speed profile adjustment simulation module is developed,based on the.NET platform.The main functions of the module include:train speed profile adjustment matching,train simulation,energy analysis.Moreover,it can communicate with the simulation driving platform based on CMC(Control Model on Chips)controller to complete the simulation of train running in typical scenarios.