Satcon Technology Corporation

David B Eisenhaure

Richard L Hockney

James R Downer

Vijay M Gondhalekar

Bruce G Johnson

James L Kirtley, Jr

Kevin J Donegan

Gita P Rao

Shankar Jagannathan

Stephen B Nichols

William E Stanton

Kevin Leary

Gary M Colello

Geoffrey B Lansberry

Ralph C Fenn

Kevin E LeRow

Timothy J Hawkey

Laban Edward Lesster

Mary Tolikas

Several embodiments of an uninterruptible power supply (UPS) system, which system provides highly reliable output power to a load using a slip-ring induction machine and a flywheel combination, are disclosed as well as methods relating thereto. In a preferred embodiment, the UPS system comprises a back-up power source, e.g., an engine and generator, and a slip-ring, or wound-rotor, induction motor and flywheel combination, which are in parallel to a primary power source, e.g., a utility grid. During normal operation of the UPS, the primary power source supplies alternating current and voltage to the load and the UPS compensates for voltage drop across the isolating inductor. Moreover, the primary power source keeps the slip-ring induction machine and flywheel in an excited state, i.e., the rotor of the slip-ring induction machine, the shaft of which is shared by the flywheel, is excited above normal synchronous speed. When the primary power source fails, the flywheel, which is rotating at super-synchronous speed and storing kinetic energy, drives the rotor of the slip-ring induction machine and generates, i.e., induces current in the stator. Accordingly, the flywheel and slip-ring induction machine combination provides instantaneous, short term power to the load until the back-up power source has powered up and been brought on line.

Uninterruptible power supply system using a slip-ring, wound-rotor-type induction machine and a method for flywheel energy storage

A charging system including an alternator, and a controller for controlling the output of the alternator to provide a required output to be in tolerance with a measured load, the controller having at least one temperature sensor, and a temperature control device, wherein the temperature control device calculates the slope of temperature variance over time and, in a state of overtemperature, decreases the value provided to the controller representing the required output.

Temperature feedback control of alternator output power

A rotary motor and a rotary magnetic bearing are integrated in a compact assembly that is contact-less. A stator assembly surrounds a ferromagnetic rotor with an annular air gap which can accommodate a cylindrical wall, e.g. of a chamber for semiconductor wafer processing. The stator assembly has a permanent magnet or magnets sandwiched between vertically spaced magnetic stator plates with plural pole segments. The rotor is preferably a ring of a magnetic stainless steel with complementary pole teeth. The stator assembly (i) levitates and passively centers the rotor along a vertical axis and against tilt about either horizontal axis, (ii) provides a radial position bias for the rotor, and (iii) establishes a motor flux field at the rotor poles. Polyphase coils wound on the stator plates produce a rotating flux field that drives the rotor as a synchronous homopolar motor. A rotor without pole teeth allows operation with an asynchronous inductive drive. A controller energizes control coils wound on each stator pole segment in response to a sensed physical position of the rotor. The control coils provide active radial position control and can actively damp tip and tilt oscillations that may overcome the passive centering.

Integrated magnetic levitation and rotation system

A flywheel energy storage device has a central shaft, a flywheel having a flywheel rotor supported by and mounted for rotation around said shaft, and a motor/generator having a stator and a rotor. The rotor is formed integrally with the flywheel rotor. The stator has an outer cylinder that is cooled by a liquid flowing in contact with its cylindrical surface. Preferably, the stator has (i) a cylindrical hub having an outer surface and longitudinal channels formed therein, (ii) a cylinder surrounding said cylindrical hub thereby providing passages through the channels, and (iii) end caps sealing the passages and providing a distribution channel for distributing fluid to said passages, thereby providing fluid cooling passages for said stator. A radial vibration dampener can be positioned at one or both ends of the shaft. The dampener has a plurality of spring members positioned between two cylindrical surfaces, one end of each spring member being attached to each cylindrical surface.

Flywheel permanent magnet machine

In an induction generator, an additional set of stator windings is provided, separate from and secondary to the main stator windings upon which the generator's output voltage is generated and supplied to the load. This separate stator winding is provided for the purpose of supplying the generator with the reactive electrical power it needs to maintain the rotating stator field and supplying any reactive power needed by the load. Thus, there is no need to use a capacitor assembly, for supplying the reactive power needed by the generator. Currents are injected into this separate winding in such a way that only reactive power is supplied to the generator. Specifically, a power measuring circuit measures the power in the additional set of stator windings, and a power error signal is formed by algebraically adding the outputs of the power measuring circuit. The power error signal is further processed and supplied as a timing control signal for generating the injected currents, which are maintained 90 degrees out of phase with an excitation voltage curve.

Externally field-controlled induction generator

A fixed gain electromagnetic actuator for controlling the position of a body including at least two pair of a magnetically permeable pole spaced from the body, bias coils about each pole, separate control coils about each pole, a bias source for the bias coils providing a current in the bias coils producing a steady-state equal strength magnetic field on opposing sides of a body, and a control source for the control coils providing a current in the control coils for producing an increase in the magnetic field on one side of the body and a corresponding equivalent decrease in the magnetic field on the opposing side of the body to compensate for any external upsetting forces acting on the body.

Fixed gain electromagnetic actuator and electromagnetic bearing

A system and method for damping narrow band axial vibrations of a rotating device in which a reaction mass is coupled to the rotating device and a reaction mass actuator is employed to move the reaction mass axially along the rotating device. An effect of vibrations on the rotating device is then measured, and in response the reaction mass is moved axially to damp the effect of vibrations and so the vibrations.

System and method for damping narrow band axial vibrations of a rotating

A magnetic rotor suspension system including a magnetic rotor having a spin axis, and a generally spherical housing spaced from the rotor. The system includes means attached to the housing for applying magnetic fields to the rotor to fix its lateral and axial position relative to the housing and to adjust the angular orientation of the spin axis of the rotor relative to the housing.

Magnetic bearing and suspension system

A magnetic bearing system for enabling translational motion includes a carriage and a shaft for movably supporting the carriage; a first magnetic bearing fixed to one of the carriage and shaft and slidably received in a first channel of the other of the carriage and shaft. The first channel is generally 'U' shaped with two side walls and a back wall. The magnetic bearing includes a pair of spaced magnetic pole pieces, each pole piece having a pair of electromagnetic coils mounted on poles on opposite ends of the pole piece proximate the side walls, and a third electromagnetic coil mounted on a pole of the pole piece proximate the backwall; a motion sensor for sensing translational motion along two axes and rotationally about three axes of the carriage and shaft relative to each other; and a correction circuit responsive to the sensor for generating a correction signal to drive the coils to compensate for any misalignment sensed between the carriage and the shaft.

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Cohasset, MA, United States of America

David B Eisenhaure