Sizing And Scheduling Technology Of Energy Storage System In Urban Rail Traction Power Supply System

Urban rail transit train has the features of low energy consumption,fast speed and environmental protection,which is an effective method to solve the urban traffic congestion.However,the large fluctuation of electric power for the traction of the urban rail transit system results in the reduced utilization of installed capacity of traction substation;leads to the one-way flow of energy of traction substation which causes a large amount of regenerated braking energy wasted.In order to reduce energy consumption and lower operating costs,the application of energy storage technology into urban rail transit has become an extensively-researched area.Energy storage system is characterized by the flexible ability of charge-discharge,and is able to even the power fluctuation and recycle the regenerated energy.By capitalizing on the complementary feature of hybrid energy storage system,high-power charge and discharge can be achieved while the energy is provided for storage capacity.Based on the foresaid background,this thesis conducts the research centered on capacity configuration and scheduling technology of ground energy storage system in urban rail transit in accordance with the actual status and power data of the trainFirstly,tractive characteristics and traction strategy of urban rail train are studied.On the basis of traction calculation of single train and combined with departing time interval of train,the multi-vehicle traction power calculation model is established upon which load characteristic of traction substation is simulated.The traction calculation is carried out based on the established model to obtain the power value of the traction substation.The traction load characteristics of different departing time intervals are analyzed from the perspective of power,frequency and energy,which lays a data foundation for the capacity configuration of ground energy storage system.Secondly,as to the ground hybrid energy storage system in traction substation,power compensation is distributed by the Fourier transform and Fourier inversion.With a view to minimize the cost of investment on traction substation and ground hybrid energy storage system,it is constructed that the optimal capacity assignment of hybrid energy storage system with traction substation,and power distribution strategy is integrated into the particle swarm optimization algorithm to search the optimization.Then,with regard to the real-time fluctuation of train traction load,the real-time scheduling strategy is established based on low-pass filtering.Considering the actual operating condition of the energy storage system,corrective measure to control energy storage and protection strategy in the event of overcharge and over-discharge are proposed based on energy storage system SOC in order to improve operational stability of the system.The simulation model is built to carry out the policy validation.This real-time scheduling strategy can meet the real-time fluctuating demand of traction load and can timely correct the deviation in the energy storage system scheduling plan caused by the real-time load fluctuation so as to avoid the overcharge and over-discharge in energy storage system.Finally,a monitoring and scheduling system of urban traffic system test platform is built based on DC microgrid.From the physical layer to the application layer,interactive data interface of back-stage management is designed,and a real-time monitoring interface is developed.The coordinated control and real-time monitoring to the system equipment can be realized through the monitoring and scheduling system of the platform.