Three phase flux switching generator in a three stage wound field synchronous machine

Patent metadata

Field	Value
Publication number	US-9543876-B2
Application number	US-201313922853-A
Country	US
Kind code	B2
Filing date	Jun 20, 2013
Priority date	Jun 20, 2013
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A brushless, three phase wound field synchronous machine (WFSM) provides an electromechanical power transfer system wherein it may serve as both a starter and a generator. Power for the excitation system of the WFSM is provided by a three phase flux switching generator (FSG). The three phase FSG also provides position sensor functionality for the WFSM when the WFSM operates in the starter/motor mode.

First claim

What is claimed is:

1. A wound field synchronous machine (WFSM) having a generate mode and a starter mode, the WFSM comprising:
a three phase flux switching generator (FSG);
an exciter coupled to said three phase FSG; and
a main machine coupled to said exciter, wherein the WFSM comprises a variable input speed range and a variable frequency (VF) architecture;
wherein said three phase FSG comprises a rotor having alternating north pole segments and south pole segments;
wherein said rotor further comprises air spaces between said alternating north pole segments and south pole segments;
wherein at least one direct axis of said rotor extends through at least one of said alternating north pole segments and south pole segments;
wherein at least one quadrature axis of said rotor extends through at least one of said air spaces;
wherein said three phase FSG directs magnetic fields primarily through said at least one direct axis, thereby substantially isolating inductance of said at least one direct axis from inductance of said at least one quadrature axis.

2. The WFSM of claim 1 operating in a generate mode wherein said three phase FSG provides excitation power for said exciter.

3. The WFSM of claim 2 wherein said exciter energizes said main machine.

4. The WFSM of claim 3 further comprising a common rotor for said three phase FSG, said exciter and said main machine.

5. The WFSM of claim 4 further comprising a rectifier coupled between said exciter and said main machine, wherein said rectifier converts AC power from said exciter to DC power for said main machine.

6. The WFSM of claim 1 further comprising:
a rotor position sensor comprising said three phase FSG.

7. The WFSM of claim 6 wherein inductance of said at least one direct axis indicates the presence of a magnetic field and inductance of said at least one quadrature axis indicates the substantial absence of a magnetic field, thereby indicating a position of a rotor of the WFSM.

8. A wound field synchronous machine (WFSM) having a generate mode and a starter mode, the WFSM comprising:
means for generating three phase excitation power;
means for generating electromotive force (EMF) in response to said excitation power; and
means for inducing a voltage in response to said EMF;
wherein the WFSM comprises a variable frequency (VF) architecture;
wherein a load coupled to said means for inducing draws a current;
wherein said means for generating three phase excitation power comprises a rotor having alternating north pole segments and south pole segments;
wherein said rotor further comprises air spaces between said alternating north pole segments and south pole segments;
wherein at least one direct axis of said rotor extends through at least one of said alternating north pole segments and south pole segments;
wherein at least one quadrature axis of said rotor extends through at least one of said air spaces;
wherein said means for generating three phase excitation power directs magnetic fields primarily through said at least one direct axis, thereby substantially isolating inductance of said at least one direct axis from a inductance of said at least one quadrature axis.

9. The WFSM of claim 8 wherein said means for generating three phase excitation power comprises a three phase flux switching generator (FSG).

10. The WFSM of claim 9 wherein said means for generating EMF comprises means for converting AC power to DC power.

11. The WFSM of claim 10 wherein said means for converting comprises a rectifier.

12. The WFSM of claim 8 further comprising:
means for sensing a position of a rotor of the WFSM;
wherein said means for sensing directs magnetic fields primarily through said at least one direct axis, thereby substantially isolating inductance of said at least one direct axis from inductance of said at least one quadrature axis.

13. The WFSM of claim 12 wherein said direct axis inductance indicates the presence of a magnetic field and said quadrature axis inductance indicates the substantial absence of a magnetic field, thereby indicating said position of said rotor of the WFSM.

14. A method of operating a wound field synchronous machine (WFSM) having a generate mode and a starter mode, the steps comprising:
generating, using a three phase flux switch generator (FSG), three phase excitation power;
generating electromotive force (EMF) in response to said excitation power; and
inducing a voltage in response to said EMF;
wherein said three phase FSG comprises a rotor having alternating north pole segments and south pole segments;
wherein said rotor further comprises air spaces between said alternating north pole segments and south pole segments;
wherein at least one direct axis of said rotor extends through at least one of said alternating north pole segments and south pole segments;
wherein at least one quadrature axis of said rotor extends through at least of said air spaces;
wherein the WFSM comprises a variable frequency (VF) architecture and directs magnetic fields primarily through said at least one direct axis, thereby substantially isolating inductance of said at least one direct axis from a inductance of said at least one quadrature axis;
wherein a load coupled to said voltage draws a current.

15. The method of claim 14 further comprising:
sensing a position of a rotor of the WFSM;
wherein said sensing step directs magnetic fields primarily through said at least one direct axis, thereby substantially isolating inductance of said at least one direct axis from inductance of said at least one quadrature axis.

16. The method of claim 15 wherein inductance of said at least one direct axis indicates the presence of a magnetic field and inductance of said at least one quadrature axis inductance indicates the substantial absence of a magnetic field, thereby indicating said position of said rotor of the WFSM.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Patel Dhaval
• Fox David A
• Ohnemus Jason A
• Markunas Albert L

Classifications

• Y02T50/671

  Cross-Sectional Technologies · mapped topic

• H02P6/186

  using difference of inductance or reluctance between the phases · CPC title

• H02P25/03

  with brushless excitation · CPC title

• H02K19/28

  for self-excitation · CPC title

• H02P1/16 Primary

  for starting dynamo-electric motors or dynamo-electric converters · CPC title