TUBULAR FLYWHEEL ENERGY STORAGE SYSTEM

摘要

A flywheel energy storage system has a tubular cylindrical steel flywheel rim that spins, with a peripheral speed greater than 200 meters per second in normal, fully charged operation, about a vertical axis inside an evacuated chamber for energy storage and retrieval. The steel rim is heat treated to a tensile yield strength greater than 100 ksi and plane strain fracture toughness in the hoop direction greater than 70 ksi(in)<1/2>. A motor generator is coupled to the flywheel for accelerating the angular velocity of the flywheel for storage of energy, and for converting angular inertial of the flywheel back into electrical energy. The motor/generator may include an assembly of permanent magnet pieces substantially filling the circumference of the inner diameter of the flywheel rim. The magnet pieces are radially magnetized and the magnet assembly forms a dipole field across the inner diameter of the magnetic assembly with magnetic flux traveling from the outer diameter of the magnets in the assembly through the steel rim to connect with other magnets in the assembly. A stationary stator is fixed in the bore of the flywheel rim and magnet assembly in a position to intercept the said dipole field induced by the magnet assembly.