Research On Stress And Dynamic Characteristic Of Composite Flywheel Energy Storage System

With the development of the economy and society, the energy crisis becomes more and more serious. As a new type of energy storage technology, flywheel energy storage system has advantage of storing more energy, fast charging and discharging, long life and no pollution. With the appearance of composite, the development of motor and magnetic bearing, the whole system has been improved a lot in terms of stress, storing density and dynamic characteristics. It brings a vast research and application prospect.This paper, on the basis of a huge of literatures and datas, makes a scientific research of system structural design, stress analysis and dynamic characteristics. It is significant for the optimal design of the flywheel system. Firstly, based on the key technologies of flywheel system, a reasonable mechanical and electrical structure is presented. A series of important components has been applied to make the whole system work normally. In allusion to carbon fiber composite flywheel, a geometric model is built and stress analytical expressions are derived utilizing the composite mechanics. A given size of single and multilayer flywheel are simulated using finite element analysis software. The process of multilayer interference fit is proved reasonable. For the single flywheel, the radial and axial stress of flywheel changes with the values of elastic modulus ratio, radius ratio and poisson’s ratio. For the multilayer flywheel, the influence of stress is found in case of multilayer isomerism and multilayer isomerism. Based on the theory of rotor dynamics foundation and modal analysis, it analyzes the critical speed and mode of vibration using software ANSYS Workbench. At last it analyzes the influence on critical speeds when the flywheel spindle structure size, gyroscopic effect, and the magnetic bearing stiffness and damping change. This can provide theoretical support for the optimization of system dynamic characteristics.