The Study Of Subway Braking Energy Utilization Based On Flywheel Energy Storage

In recent years, the development of urban rail transit in our country is very prosperous. Study of regenerative braking energy utilization technology for urban rail transit and improvement of the energy utilization rate, which are in line with the direction of the development of urban rail transit, has important significance and practical value on the energy-saving emission reduction and sustainable development. Flywheel energy storage system with rapid response speed, high power density and friendly environment compatibility, has unique advantages and development prospects on enhancing Metro regenerative braking energy utilization rate and stabilizing the traction network voltage fluctuation.First of all, the operating principle of flywheel energy storage device is analyzed, and the impact of the performance parameters of flywheel energy storage system is determined. Then the energy conversion relationship of flywheel energy storage system is researched.Secondly, based on the dynamic analysis and braking characteristic curve method, the energy size of regenerative braking of Metro locomotive is calculated quantitatively, which lays the foundation for designing the capacity of flywheel energy storage system. At the same time, using MATLAB/SIMULINK tools to build third rail supply mode DC traction power supply system simulation platform. This platform providing an analytical tool for the study of the energy relationship of subway locomotive under different operating conditions.Thirdly, the control strategy of the flywheel motor is analyzed. When the energy storage system works in the energy storage mode, the control strategy based on feed forward decoupling control is adopted in the flywheel motor. At the same time, in order to improve the performance of the control system, the inverse system method and the sliding mode control theory are used in the design of the control algorithm.Finally, in order to expand the capacity of flywheel energy storage system, this paper puts forward the scheme of flywheel energy storage array. The flywheel units connected in parallel with the DC bus, which is based on the principle of power matching, are controlled by the two-stage controller. At the same time, SIMULINK simulation model is built, which can verify the flywheel array system work under different conditions. The simulation results show that the flywheel array system designed in this paper can effectively recycle Metro regenerative braking energy, and achieve the function of traction network voltage stability.