Three phase flux switching generator in a three stage wound field synchronous machine
AssigneeHamilton Sundstrand Corporation
InventorsDhaval Patel, David A. Fox, Jason A. Ohnemus, Albert L. Markunas
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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.
Claims16
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.
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.
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.
Dependencies are inferred from the claim text.