The Stress Analysis And Optimization On The Main Part Of The Composite Storage Flywheel Rotor

The high-speed flywheel battery is a new storage device, compared to other energy storage with high energy density, fast charge and discharge, low pollution, high efficiency, widely applicable, long life, etc. With the growing global energy scarcity anddeteriorating environment, the high-speed flywheel battery has broad applicationprospects. The high-speed flywheel battery is mainly composed of the flywheel rotor, bearings, electric/generator, power converter, vacuum room.Flywheel energy storage density is decided by the maximum speed of the, and the maximum speed is limited by the radial strength. The flywheel can not further improve the speed, is because there is no further improvment of the radial strength of the rotor. Solve this problem are mainly two directions:one is to increase the transverse strength ofthe material itself; the other is through the design of the rotor structure, to increase theradial strength.The main result of this paper is to increase the radial strength by the structural design. Analyzing the results of calculation and simulation, the decisive factor in the design of multi-ring perssfit assembly is the thickness of the outermost layer, which determines the maximum flywheel speed. The outermost rim thickness has three major constraints:First, the material thermal residual stress generated during the curing cooling; second, the centrifugal force generated at the rim internal by rhe flywheel high-speed rotation; third, the pre-stress generated in the multi-ring perssfit assembly. In order to clarify the impact of these three factors for the rim structure, integratedly useing Ansys, UG and Mathematica software, set up the macro and micro models of the flywheel rotor, deduces the structural stress and strain equation of the multi-ring perssfit assembly, analysis the weight of each parameter. Have analysised out of the two main failure modes of the flywheel by the simulation. Then I calculated the actual maximum speed of the flywheel. Finally I designed the flywheel rotor with a maximum energy density, in the conditions of fixed rotor height and outer diameter.