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US 7,443,070 B2Granted
Method and apparatus for controlling an electric machine
AssigneePratt & Whitney Canada Corp.
InventorsKevin Dooley, Michael Dowhan
Life of this patent
Estimating the term…
Abstract
The invention provides a method and apparatus for controlling a machine in which the magnetic flux emanating from a rotor is selectively diverted to a second path in the stator which bypasses the winding or windings so as to magnetically de-couple the winding or windings from the rotor.
Claims17
An electric machine comprising:
- a magnetic rotor;
- a stator having a face adjacent the rotor, the stator including at least one slot defined therein and at least one winding disposed in the at least one slot, the at least one slot defining a slot gap across the at least one slot, wherein the at least one slot at least partially defines a primary magnetic circuit in the stator, the primary magnetic circuit having a reluctance and extending around the at least one slot;
- and
- a member radially moveable between a first and second position during operation, the member substantially bridging the slot gap when in the second position to substantially close the slot gap and thereby close a second magnetic circuit in the stator, the second magnetic circuit bypassing a portion of the at least one slot containing the at least one winding, the second magnetic circuit having a reluctance not greater than the primary magnetic circuit reluctance.
1 more element
An electric machine comprising:
- a magnetic rotor, the rotor including a plurality of permanent magnets;
- and
- a stator defining at least part of a primary magnetic circuit and a secondary magnetic circuit therein, the primary magnetic circuit adapted to guide magnetic flux emanating from the rotor around at least one winding to induce a voltage in the winding, the secondary magnetic circuit adapted to guide said magnetic flux emanating from the rotor substantially along a stator surface adjacent the rotor to thereby bypass the at least one winding,
- wherein the secondary magnetic circuit is selectively closeable, and wherein the secondary magnetic circuit has a reluctance not greater than a reluctance of the primary magnetic circuit.
1 more element
Dependencies are inferred from the claim text.