Abstract
We produced flywheel energy storage system, using a CFRP flywheel and a newly designed motor/generator. The flywheel consists of high-modulus graphite/epoxy filament wound composites, which are designed for better stress distribution. This allows the flywheel to rotate at higher speed. The motor/generator mounted inside the flywheel provides high efficiency energy transfer into and out of the system because it has no core in the coil. The regenerative efficiency was evaluated under an atmospheric and vacuum condition. In the evacuated shroud the efficiency was over 85%. High speed FW system must be attended evacuated shroud with the adaptable equipment for reduced aero resistance. We propose the new theory to floating shrouds that we had being the study, several years ago, recently we had the experimental evaluations to effect for reduced aero resistance only by floating shrouds. This paper describes the problems of evacuated shroud and the effect of floating shrouds.
