Architecture for electric machine

• US 7,583,063 B2
• Filed: 11/16/2007
• Issued: 09/01/2009
• Est. Priority Date: 05/27/2003
• Status: Expired due to Term

• Current Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Original Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Inventors: Dooley, Kevin Allan
• Primary Examiner(s): Gonzalez; Julio C
• Assistant Examiner(s): Cuevas; Pedro J
• Application Number:
  US11/941,396
• Publication Number:
  US 20080079401A1
• Time in Patent Office: 655 Days
• Field of Search: 322/33, 310/114, 290/52
• US Class Current: 322/33
• CPC Class Codes: H02K 1/2791 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 16/04 Machines with one rotor and two stators
• CPC Class Codes: H02K 21/14 with magnets rotating within the armatures
• CPC Class Codes: H02K 21/22 with magnets rotating around the armatures, e.g. flywheel magnetos
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 3/16 for auxiliary purposes, e.g. damping or commutating
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: H02K 3/46 Fastening of windings on the stator or rotor structure
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 9/02 Details of the control

Abstract

The invention includes an electric machine having a rotor, stator and at least one winding in the stator adapted to conduct a current, and a secondary winding, electrically isolated from the first winding and inductively coupled to the first winding, which may be used to control at least one of the output voltage and current of the first winding.

Claims

1. A method for operating a gas turbine engine, comprising the steps of:

providing the gas turbine engine, the engine having a main shaft drivingly connected to a multiple power output channel electric machine, the machine having a single rotor and a single stator, the stator being a cylinder composed of a plurality of non-overlapping sectors, each sector having a set of stator windings associated therewith, each set having at least one primary and one secondary windings in the sector, the at least one secondary winding adjacent to and electrically isolated from the at least one primary winding, the stator sector primary windings being electrically independent of one another, the stator sectors primary windings each providing one of said multiple power output channels;

providing an electrical distribution system electrically connected to said power output channels of the machine, the channels connected to the electrical distribution system in parallel to one another;

operating the engine to rotate the rotor and thereby generate electricity;

in normal machine operation, combining the power output channels to provide a single power output to the electrical distribution system; and

in the event of a fault in a said stator sector, manipulating electricity in the secondary winding of the faulted sector to increase the impedance of the faulted sector and thereby reduce current output of the at least one primary winding of the channel associated with said faulted sector while continuing operation of a remainder of said channels to provide power output to the electrical distribution system.

2. The method as defined in claim 1, wherein in normal operation, the power output of each channel provides substantially equal current output to the electrical distribution system.

3. The method as defined in claim 1, wherein two channels are provided, the power output of each channel in normal operation providing substantially half of a current output provided to the electrical distribution system.

4. The method as defined in claim 1, wherein the electrical distribution system comprises redundant engine accessory systems.

5. The method as defined in claim 1 further comprising providing electricity from the electrical distribution system to at least one of the group consisting of a plurality of power conditioning units, a plurality of engine pumps, and a plurality of electrically-run accessories.

6. The method as defined in claim 1, further comprising the step of open-circuiting the at least one secondary winding of said at least one channel associated with said fault to thereby reduce electrical output of the at least one primary winding of said channel.

7. The method as defined in claim 1, wherein three primary windings are provided in a 3-phase configuration in each said sector.

8. The method as defined in claim 1, wherein each channel is connected to the electrical distribution system via a corresponding primary circuit terminal.

9. The method as defined in claim 2, further comprising increasing the output of a remainder of the channels to provide an output current substantially equal to a current level of the machine in normal operation prior to the fault.

10. The method as defined in claim 3, the power output of the non-faulted channel providing substantially twice a current output level provided by the channel prior to the fault.