Patent ID: 7068014
Filing Date: 2006-06-27
Classification: H02K,Y02E

Abstract:
1. A flywheel energy storage system for preventing power interruptions to a load from interruptions of primary power, comprising: a flywheel that is supported for rotation about an axis on a bearing system, and a motor-generator having a stator and a rotor coupled with said flywheel, said motor-generator has multiple stationary armature windings and a field coil; said field coil generates flux that passes through said armature windings as said rotor rotates; a rectifier connected to said primary power for delivering rectified primary power to a DC buss; an inverter connected to said DC buss for converting power from said DC buss to output power to said load; a synchronous inverter for delivering synchronized power to excite said armature windings during recharging of said flywheel; a field controller for maintaining power to said field coil during standby operation such that the current to said field coil remains substantially constant during a period including immediately before an interruption of primary power and immediately after an interruption of primary power.