Patent ID: 6720674
Filing Date: 2004-04-13
Classification: H02J,H02K,Y02E

Abstract:
A device for prevention of power interruptions to a DC bus, comprising:a flywheel supported for rotation about an axis of rotation on a bearing system in a drag reducing internal atmosphere inside a container; said flywheel having a large moment of inertia about said rotation of inertia; an integral brushless permanent magnet excited motor/generator having low resistance armature coils coupled to said flywheel for accelerating and decelerating said flywheel for storing and retrieving energy stored as rotational inertia of said flywheel; a closed loop operated synchronous inverter for supplying synchronous power to armature coils of said motor/generator for accelerating said flywheel; a rectifier connecting said armature coils of said motor/generator to said DC bus for supplying unregulated voltage power to said DC bus during an interruption of primary utility power; whereby the voltage of said DC bus falls as the speed of said flywheel slows during its discharge of useable energy to said DC bus, the amount of said usable energy delivered to said DC bus during a utility power interruption is maximized by a combination of a low voltage drop in said armature coils of said motor/generator and by sufficient inertia in said flywheel to reduce rates of decay of said motor/generator back emf.