Research On Energy Management Strategy Of Hybrid Energy Storage System For Urban Rail Transit

Urban rail transit has the advantages of fast punctuality,large carrying capacity,safety and comfort,and green energy conservation,and gradually plays an important role in urban public transportation.However,the distance between the station and the station is short,the vehicle operating density is high,and the frequent and braking characteristics make the train require a large starting power during the traction acceleration process,and generate huge regenerative energy when the brake is decelerated.For the characteristics of high power and large energy of urban rail transit,how to effectively suppress the fluctuation of DC traction network pressure,fully recover regenerative braking energy,and improve energy utilization are the hot issues in the field of urban rail transit.To solve this problem,the paper adopts a type of hybrid energy storage device,which combines a high energy density battery device and a high power density supercapacitor device to form a hybrid energy storage system to meet the dual demand of urban rail transit traffic power and energy.Therefore,this paper mainly studies the charging and discharging control strategy and energy management strategy of urban rail transit hybrid energy storage system.Firstly,the principle of urban rail transit traction drive system is analyzed,and the experimental simulation platform of urban rail transit traction power supply and transmission system based on permanent magnet synchronous motor vector control is built.The actual running conditions of urban rail transit train are simulated,and all the links of the experimental simulation platform are carried out.Detailed principles discussion and model modeling.Then,the hybrid energy storage system is studied.From the performance and circuit equivalent model of the battery and supercapacitor to the working principle of the bidirectional DC/DC converter,a detailed introduction and modeling analysis are made,and the appropriate hybrid storage is selected.The system topology and the charge and discharge control strategy of the hybrid energy storage systembased on bidirectional DC/DC converter are designed and simulated.The simulation results verify that the hybrid energy storage system and its charge and discharge control strategy can significantly suppress the traction network voltage.Fluctuating and effectively absorbing regenerative braking energy.Finally,the deficiencies of traditional voltage-stratified urban rail transit hybrid energy storage system control strategies are analyzed.In order to give full play to the advantages of hybrid energy storage systems,the paper proposes an energy management strategy based on fuzzy logic control for urban rail transit hybrid energy storage systems.Coordinated control of the hybrid energy storage system to improve the utilization rate of regenerative braking energy.Using Matlab/Simulink to carry out simulation experiments and comparing and analyzing the simulation results,it is proved that the energy management strategy of urban rail transit hybrid energy storage system based on fuzzy logic control can make the coordinated energy storage device coordinate control and improve the energy-saving and voltage-regulating effect of the urban rail hybrid energy storage system as a whole.