Abstract: A flywheel system includes a fixture providing a base and a stator, rotor having a cavity to receive the stator, a generator/motor module having a plurality of permanent magnets mechanically coupled to the rotor and an active magnetic bearing module. The active magnetic bearing module includes a plurality of magnetizable elements mechanically coupled to or integrated in the rotor, and a plurality of electromagnets mechanically coupled to a shaft and configured to magnetically couple with the plurality of first magnetizable elements to actively stabilize the rotor relative to the fixture. The windings of the generator/motor module are arranged around the rotation axis of the rotor at a first distance from the rotation axis of the rotor, the electromagnets of the active magnetic bearing module are arranged around the rotation axis of the rotor at a second distance, and the first distance is greater than or equal to the second distance.

Abstract: A flywheel system includes a fixture including a bottom support, a rotor characterized by a gravitational load and configured to rotate above the bottom support about a rotation axis, and a bottom magnetic levitation bearing. The bottom magnetic levitation bearing includes (a) a ring of first magnets mechanically coupled with a bottom end of the rotor, (b) a ring of second magnets mechanically coupled to the bottom support, beneath the ring of first magnets, the second magnets repelling the first magnets to magnetically support at least a portion of the gravitational load above the bottom support, (c) a ring of third magnets mechanically coupled with the bottom end, and (d) a ring of fourth magnets mechanically coupled to the bottom support radially outwards from the ring of third magnets, the fourth magnets repelling the third magnets to at least reduce radial decentering of the rotor relative to the fixture.

Abstract: A flywheel system includes a rotor and a fixture. The rotor forms an aperture. The fixture includes a bottom support, a top support, and a shaft connecting the bottom support to the top support. The shaft passes through the aperture. The bottom support and the top support are outside opposite ends of the aperture. The rotor is configured to rotate about the shaft. A method for operating a flywheel system includes converting between rotational energy of a rotor and electrical energy in windings of a generator stator that is implemented in a stationary shaft passing through an aperture of the rotor, while the rotor is rotating about the shaft.

Abstract: A method for operating a microgrid electric power generation system includes delivering energy to an electric power bus at least partially from one or more kinetic generators electrically coupled to the electric power bus, controlling the one or more kinetic generators in response to a change in a load such that a magnitude of a voltage on the electric power bus remains within a predetermined voltage range, and controlling one or more combustion generators electrically coupled to the electric power bus based at least in part on an operating state of the one or more kinetic generators. The one or more kinetic generators are capable of (a) delivering energy stored therein to the electric power bus, and (b) storing energy in kinetic form.

Abstract: A flywheel system includes a fixture providing a base and a stator, rotor having a cavity to receive the stator, a generator/motor module having a plurality of permanent magnets mechanically coupled to the rotor and an active magnetic bearing module. The active magnetic bearing module includes a plurality of magnetizable elements mechanically coupled to or integrated in the rotor, and a plurality of electromagnets mechanically coupled to a shaft and configured to magnetically couple with the plurality of first magnetizable elements to actively stabilize the rotor relative to the fixture. The windings of the generator/motor module are arranged around the rotation axis of the rotor at a first distance from the rotation axis of the rotor, the electromagnets of the active magnetic bearing module are arranged around the rotation axis of the rotor at a second distance, and the first distance is greater than or equal to the second distance.