Patent ID: 6566775
Filing Date: 2003-05-20
Classification: F16C,H02K,Y02E

Abstract:
A flywheel battery, for storing electric power as kinetic energy from a dc power buss and returning power to said buss with minimal losses, comprising:motor/generator means, including polyphase stator windings for conducting polyphase sinusoidal currents, which are formed from multi-strand insulated conductors for eddy blocking and bucking, a permanent-magnet rotor for providing radial flux that interacts with said currents, and rotor angle sensors, for providing polyphase feedback signals which vary essentially sinusoidally with rotor angle; a flywheel rim, for providing rotary inertia for storing said kinetic energy, attached to said motor/generator rotor and concentric therewith, the combination having a vertical spin axis; power interface electronics, connected to said dc power buss and to said polyphase stator windings of said motor/generator, said electronics responsive to the rotor angle sensors and to the buss voltage, for controlling polyphase current through said stator windings so its resultant magnetic field rotates synchronously with said rotor, axial servo means, including axial position sensors, also including annular permanent-magnet and magnetic materials for producing concentric annular poles above the rotor and flywheel, for providing axial force with minimal magnetic cycling, for levitating the rotor and flywheel and for passive radial centering, including a concentric coil between said poles, its bi-directional current controlled by an axial servo loop responsive to said axial position sensors, for stabilizing the axial force, including a current integrator, for adjusting axial position to reach zero steady-state current; radial servo means, including radial position sensors at the rotor top and bottom, including radial electromagnets aligned thereto, for radially centering the rotor by forces from magnetic fields with flux paths substantially radial and axial in cooperating rotor magnetic material, controlled by radial servo loops responsive to said radial position sensors and having dead-band means wherein centering is maintained by said passive radial centering, gravity, and gyrodynamics.