Study On Energy Optimization Dispatching Method Of High-speed Railway Power Supply System With Photovoltaic And Hybrid Energy Storage System

Driven by the ‘carbon peak,carbon neutrality’ strategy,integrating the renewable energy power generation system represented by photovoltaics to the electrified railway power supply system can not only promote the nearby consumption of new energy,but also further improve the safety and economy of system operation by integrating energy storage devices.However,how to optimize the scheduling of system energy based on the uncertainty of photovoltaic power generation system output and traction load to achieve the optimal operation of the system is still worthy of further study.Around this problem,the main work of this paper is as follows:Firstly,the significance of this research is expounded.The application status of photovoltaic and hybrid energy storage systems in the field of rail transit at home and abroad is introduced.The current research status of energy optimization scheduling methods for electrified railway power supply systems with photovoltaic and energy storage is summarized.Combined with the structure of electrified railway power supply system and the characteristics of traction load,the selection of energy storage medium,the access mode and modeling method of photovoltaic and energy storage system are analyzed,which provides a theoretical basis for the establishment of subsequent energy optimization dispatching model.Secondly,considering that the high-speed railway power supply system mainly includes traction power supply system load and power system distribution system load,in order to further improve the utilization rate of regenerative braking energy and reduce the peak load of high-speed railway power supply system,the energy feedback device is used to connect the traction power supply system with the power distribution system.The structure,the photovoltaic power generation system and the hybrid energy storage system are introduced,and the system energy optimization scheduling model considering the life cycle cost is established.According to the measured data of high-speed railway power supply system,the optimal operation plan of the system is obtained by mixed integer linear programming method.The structure and the proposed energy management strategy reduce the daily operating cost of the system by 11.61%.Finally,because the uncertainty and prediction error of traction load and photovoltaic power generation system will affect the system operation and energy allocation,and the operation plan obtained by global optimization cannot be directly applied to the actual operation of the system,and the energy density of super capacitor in hybrid energy storage system is small.In the actual operation process,SOC frequently reaches the upper and lower limits,which will lead to severe power fluctuation and affect the safe and stable operation of the system.In the fourth chapter of this paper,based on the idea of model predictive control,a real-time optimal control method of system energy including rolling horizon optimization and energy storage system correction is proposed.With the goal of minimizing the daily operating cost of the system,the particle swarm optimization algorithm is used to solve the optimal operation plan of the system in a period of time.The proposed optimal scheduling method reduces the daily operating cost of the system by 4.6% compared with the day-ahead optimal scheduling method,and by 2.6% compared with the rolling optimization strategy without correction feedback.