Optimal Sizing And Control Of Energy Storage System For New Energy Tram

With the development and construction of the city,the urban area is constantly increasing,and people's demand for urban rail transit is increasing.As the new energy tram has the advantages of large passenger capacity,high speed,energy saving,environmental protection and economy,the development of new energy tram will ease urban traffic pressures,improve operating efficiency,and realize the recycling of energy.The onboard energy storage system is the power source for new energy trams,and the optimization of matching of its key parameters is an important prerequisite for the safe operation of new energy trams.Further optimizing the control of the onboard energy storage system can not only improve the life of the energy storage system within a reasonable range,but also reduce the loss of the energy storage system,thereby improving the energy conversion efficiency of the vehicle.In this paper,the hybrid energy storage system for new energy trams is the main research object.Firstly,it analyzes the operating characteristics of trams,and builds system-level train dynamics model,battery model,super capacitor model and onboard DC/DC model from the perspective of energy flow.It provides a theoretical basis for the follow-up R&D of the new energy tram operating simulation software.Then according to the dynamic model of new energy tram and the model of energy storage system,this paper analyzes the application requirements of the software and completes the overall framework of the new energy tram operating simulation software.The algorithm flow including train traction calculation and onboard energy storage system solution is designed.Based on Matlab simulation environment,the development of the software and the design of the upper GUI interface are completed.It provides a simulation platform for the follow-up of the optimal sizing and control of energy storage systems for new energy trams.Then,the parameter matching optimization method of onboard hybrid energy storage system is proposed in the paper.The Gaoming District line is used as working conditions,and the tram data running on the line is used as input parameters.Taking the life cycle cost including initial investment cost,operation cost and replacement cost as the objective function,considering the rate,volume,weight and SOC interval as boundary conditions,particle swarm optimization(PSO)algorithm is used to calculate the optimal results and acquire the key configuration parameters and control strategy parameters of the onboard hybrid energy storage system with the lowest life cycle cost.Finally,this paper makes further analysis on the control strategy of onboard hybrid energy storage system.Based on the objective of minimizing the loss of the onboard hybrid energy storage system under full operating conditions,the corresponding boundary conditions are set.The dynamic programming algorithm is used to find the optimal control strategy for the entire operating conditions,and the simulation results are analyzed theoretically.