Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
1999-12-30
2001-10-30
Mullins, Burton S. (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S114000, C310S256000, C318S727000, C322S047000
Reexamination Certificate
active
06310417
ABSTRACT:
DESCRIPTION OF THE BACKGROUND ART
There is an existing type of induction motor known as a brushless doubly fed induction motor (BDFIM), which has two sets of stator windings for operation with two p-poles and two q-poles. The rotor winding has a two-pole (p+q) nested cage. The existing extended rotor cage technology has drawbacks associated with a type of energy transfer known as cluttered energy transfer. It utilizes a drive with a relatively narrow speed range and not insignificant energy losses.
There is a need for a lower than synchronous speed drive having a wider speed range. To provide such a drive, it is necessary to control the power which is related to the slip of the rotor at speeds lower or higher than the speed of the stator rotating field. This would reduce energy loss and lower the cost for adjustable speed motor drives and power generation.
SUMMARY OF THE INVENTION
The invention relates to a new hybrid-secondary uncluttered induction machine. The hybrid secondary can be switched between an effective resistance, a source of DC bias voltage or an AC source of variable frequency. The rotor current is magnetically coupled to the stator through an uncluttered rotating transformer.
This machine of the present invention can be used as a cost effective, slip-energy-controlled, adjustable speed induction motor that operates below synchronous speed. This machine may take the form of either a motor or a generator having a wide speed range of operation which extends both above and below the synchronous speed of the stator rotating field.
The uncluttered coupling of the rotating transformer allows the slip energy to be transferred without an excessive reduction in torque.
Magnetic saturation is utilized at extremely low slip frequency for a full-load operation. The power required for magnetic saturation is low.
The slip energy control power is relatively small when compared with the full load rating of the motor.
A motor according to the present invention has a potential to be fed from both the stator of the induction motor and the stator of the rotating transformer for higher than synchronous speed operation. It also has a potential to be used for a wide-speed-range induction generator.
Other objects and advantages of the invention, besides those discussed above, will be apparent to those of ordinary skill in the art from the description of the preferred embodiment which follows. In the description, reference is made to the accompanying drawings, which form a part hereof, and which illustrate examples of the invention. Such examples, however, are not exhaustive of the various embodiments of the invention, and therefore, reference is made to the claims which follow the description for determining the scope of the invention.
REFERENCES:
patent: 3069577 (1962-12-01), Lee
patent: 3144597 (1964-08-01), Lee
patent: 3226582 (1965-12-01), Beckwith
patent: 4701691 (1987-10-01), Nickoladze
patent: 4785213 (1988-11-01), Satake
patent: 4965477 (1990-10-01), Stadler et al.
patent: 5059876 (1991-10-01), Shah
patent: 5254894 (1993-10-01), Satake et al.
patent: 5285124 (1994-02-01), Satake et al.
patent: 5594186 (1997-01-01), Krause et al.
patent: 5838085 (1998-11-01), Roesel et al.
patent: 5886445 (1999-03-01), Hsu
patent: 5898287 (1999-04-01), Roberti et al.
patent: 55053196 (1980-04-01), None
patent: 62104491 (1987-05-01), None
Shibashis Bhowmik, et al., “Performance Optimization for Doubly-Fed Wind Power Generation Systems,”IEEE, 1998 IAS Conference, vol. 3, pp. 2387-2394.
Liao Y.: “Design Of A Brushless Doubly-Fed Induction Motor For Adjustable Speed Drive Applications”, Oct. 6, 1996, pp. 850-855, XP000731208.
Lockheed Martin Energy Research Corporation
Mullins Burton S.
Quarles & Brady LLP
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