Optimal Configuration Of Ground Energy Storage System Of Intermittent Power Supplying Tramcar

Urban rail transit has been increasingly demanded along with the continuous development of economy and the accelerated urbanization.With advantages such as high efficiency,large transport volume,low cost,short construction cycle,fast speed,punctuality and comfort,recoverable energy and flexible departure interval,etc.,the new energy intermittent power supplying tramcar equipped with on-board energy storage system is bounded to be popular in future with a promising prospect.The proper and efficient charging mode is crucial for the safe operation of tramcar.Taking the actual situation in Guangzhou as an example,achieving "peak shaving and valley filling" by means of increasing ground energy storage system and changing the existing power supply mode of tramcar is advisable for sake of problems such as high charging power,low transformer load,low efficiency of power supply system and high basic capacity cost of distribution system,etc..The optimal configuration of key parameters of ground energy storage system,which is a key component of the power supply system,is an essential prerequisite for safe power supply:feasible optimal control of power supply system can not only prolong the use of energy storage system in a possible range,but also improve the efficiency of the whole power supply system.First of all,based on a national rail transit project,this thesis,focusing on the charging system of a tramcar charging station in Guangzhou,puts forward the structural topology of power supply system transformation,analyzes the practice of tramcar charging,builds a systematic power supply system model covering battery model,super capacitor model and device efficiency from perspective of energy flow and lays a theoretical foundation for the follow-up study.Secondly,this thesis proposes a way to optimize the configuration of ground energy storage system parameters,takes the charging practice of a tram line in Guangzhou as the input parameter,takes the whole life cycle cost including initial investment cost,replacement cost and operation cost as the objective function,takes the charging and discharging rate,voltage and SOC interval as boundary conditions,optimizes by means of particle swarm optimization(PSO)and gets access to the key configuration parameters and control strategy parameters of the ground energy storage system with the lowest whole life cycle cost.Finally,this thesis analyzes the energy supply distribution strategies of power grid and ground energy storage system further,improves the traditional threshold control strategy with the fuzzy control strategy and conducts simulation verification,with the economy of whole life cycle costs of different power supply system transformation schemes and the feasibility of simulation results compared and analyzed.