| 摘要 |
Electric power is stored in a flywheel system, from a DC power buss, and supplied to the buss, through power electronics associated with a motor/generator, its rotor integral with a flywheel supported by magnetic bearings. The power is reciprocally converted by the motor/generator, controlled by current in its polyphase stator windings, between electricity and kinetic energy. The rotor contains radial-field permanent magnets attached to supporting outer annular high-permeability steel, attached to inner annular steel. This completes a path through the stator windings, for the rotor field, which interacts with current in the windings, to produce torque between the rotor and the stator. Polyphase sinusoidal currents in the stator windings are controlled by the associated electronics, responsive to respective rotation angle sensors and the DC power buss voltage, plus other commands. During normal operation, the rotor assembly is supported by axial attraction of its annular high-permeability axial poles near its top and bottom, to fixed juxtaposed annular magnetic poles above and beneath it. The axial magnetic field also provides passive radial centering. The rotor assembly is released by mechanical backup bearings as magnetic bearings are activated at power-up, and then normally remain disengaged until the last event of a power-down sequence. Axial position stability is provided by axial electromagnets at each end of the rotor assembly. A coil current time-integral is combined with axial position and rate feedback, so that average coil current is continuously adjusted to zero, by axial position adjustment. Radial electromagnets damp flywheel swirling at resonant vibration frequencies, and constrain radial position during possible earth tremors. Affixed to orbital satellites, arrayed 2, 3, or 4 flywheel systems can provide power storage and regeneration as needed. Their radial servos can also provide spin axis precession torques to control satellite attitude.
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