William Colin Stanton, 444301 S 88Th St, Fort Smith, AR 72903

4392100, Jul 5, 1983

Aug 1, 1980

6/174552

William E. Stanton - Newton MA
David B. Eisenhaure - Hull MA
Robert D. Drescher - Cambridge MA

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

H02P 540

318803

An optimum efficiency control system for a variable torque/speed rotary a. c. induction machine including means for varying the frequency and magnitude of the excitation voltage/current supplied to the machine in three optimum efficiency regions of operation, a first fixed slip frequency region, a second flux saturation region, and a third voltage saturation region; and means for commanding the means for varying in the first fixed slip frequency region of operation with an excitation frequency command signal derived from the machine rotor speed and unconstrained maximum efficiency slip frequency, and an excitation voltage/current command signal derived from the difference between the commanded torque/speed of the machine and its actual torque/speed; in the second flux saturation region of operation with an excitation frequency command signal derived from the machine rotor speed and slip frequency command signal derived from the machine rotor speed and slip frequency which is a function of the difference between the commanded torque/speed of the machine and its actual torque/speed; and an excitation voltage/current command signal derived from the difference between the saturation flux and actual flux in the machine; and in the third voltage saturation region of operation with the saturation voltage and an excitation frequency command signal derived from the machine rotor speed and slip frequency which is a function of the difference between the commanded torque/speed and actual torque/speed of the machine.

4179729, Dec 18, 1979

Apr 15, 1977

5/787930

William E. Stanton - Newton MA
David B. Eisenhaure - Hull MA
George A. Oberbeck - Belmont MA
Kenneth Fertig - Sudbury MA

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

H02M 700

363175

A power conversion system for converting between electrical power at different frequencies, including a rotary electrical machine including a rotor, a stator, first and second independently controllable field windings, and at least one armature winding for each phase; a switching circuit including a plurality of switching devices and having first terminal means interconnected with the armature winding which carries a high frequency signal established by the machine, and a second terminal for interconnection with an impedance establishing a lower frequency signal; the first field control circuit for monitoring the machine to sense phase difference between the optimum zero crossings and actual zero crossings of the higher frequency signal for driving the first field winding to adjust the phase of the higher frequency signal to minimize the phase difference; a second field control circuit for modulating the higher frequency signal carried by the armature winding with the lower frequency signal and for monitoring the second terminal means to sense amplitude difference between a selected one of the voltage and current parameters of the lower frequency signal and a reference level for driving the second field winding to adjust that parameter towards the reference level; and a switch firing circuit responsive to the machine voltage and one of the voltage and current parameters of the lower frequency signal at the second terminal means for selectively triggering to the on state and self-commutating to the off state the switching devices synchronously with the zero crossings of the higher frequency signal for transferring power between the higher and lower frequency signals through the switching circuit.

6049148, Apr 11, 2000

Oct 2, 1998

9/166064

Stephen B. Nichols - Chelsea MA
Shankar Jagannathan - Waltham MA
Kevin Leary - Winchester MA
David Eisenhaure - Hull MA
William Stanton - Waltham MA
Richard Hockney - Lynnfield MA
James Downer - Canton MA
Vijay Gondhalekar - New York NY

SatCon Technology Corporation - Cambridge MA

H02K 1100

310 68B

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.

5818137, Oct 6, 1998

Oct 26, 1995

8/548692

Stephen B. Nichols - Chelsea MA
Shankar Jagannathan - Waltham MA
Kevin Leary - Winchester MA
David Eisenhaure - Hull MA
William Stanton - Waltham MA
Richard Hockney - Lynnfield MA
James Downer - Canton MA
Vijay Gondhalekar - New York NY

SatCon Technology, Inc. - Cambridge MA

H02K 709

310 905

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.

4152637, May 1, 1979

Jun 20, 1977

5/808067

George A. Oberbeck - Belmont MA
William E. Stanton - Newton MA
Andrew W. Stewart - Weymouth MA

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

G05F 122
G05F 100

323 6

A saturable reactor device for limiting alternating and direct current in an external electric circuit. In one form, the required magneto-motive force (mmf) bias for the saturable reactor is provided by a controllable flux bias element in order to minimize the required bias power. A current sensor provides a control signal representative of the alternating or direct current passing between the source and the load. This signal is used to control the magnitude of the bias so that the mmf provided by the bias element is a function of the current driving the load, permitting a current limiting threshold at a predetermined percentage of the current applied to the load. In an alternate form, the device may be adapted to limit bipolar current in the external circuit. In this form, the device includes an input circuit and an associated direct current saturable reactor limiter. In response to direct current of either positive or negative polarity passing through the external circuit, unidirectional current is driven through the input coil of the direct current limiter.

6262505, Jul 17, 2001

Mar 26, 1997

8/824862

Richard L. Hockney - Lynnfield MA
Stephen B. Nichols - Charlestown MA
Geoffrey B. Lansberry - Cambridge MA
Francis E. Nimblett - Beverly MA
Dariusz A. Bushko - Hopkinton MA
Gita P. Rao - Belmont MA
Luka Serdar - Lexington MA
Michael E. Amaral - Norwood MA
William E. Stanton - Waltham MA
James O'Rourke - Woburn MA

SatCon Technology Corporation - Cambridge MA

H02K 709
H02K 524

310 905

A power supply device for providing uninterrupted power for a period of time is disclosed. The power supply device has a controller and a flywheel device. The flywheel device has a housing that contains a flywheel rotor and a motor/generator rotor. The flywheel rotor and the motor/generator rotor are mounted on a common shaft. An active axial magnetic bearing is located to support the shaft for frictionless rotation. The bearing provides support for the shaft, the flywheel rotor and motor/generator rotor. The axial magnetic bearing is attached to the housing and provides, in combination with the motor/generator rotor, a flux path and magnetic field to exert a magnetic force to lift the motor/generator rotor and the shaft on which it is mounted.