초록 ▼

An electric machine is disclosed comprising a first energy source, a second energy source, and a stator which comprises a first set of windings and a second set of windings. The electric machine has a rotor and a controller, the controller configured to control the first energy source to supply a fi

An electric machine is disclosed comprising a first energy source, a second energy source, and a stator which comprises a first set of windings and a second set of windings. The electric machine has a rotor and a controller, the controller configured to control the first energy source to supply a first current to the first set of windings and control the second energy source to supply a second current to the second set of windings. The controller also detects an angular position of the rotor, detects the first current, detects the second current, and determines an optimum phase shift angle of the first current based on the angular position of the rotor, the first current, and the second current. The controller controls the first energy source based on the optimum phase shift angle to modify the first current supplied to the first set of windings.

대표청구항 ▼

1. An electric machine comprising: a first energy source;a second energy source;a stator, wherein the stator comprises: a first set of windings comprising AC field windings that are coupled to the first energy source; anda second set of windings comprising DC field windings that are coupled to the s

1. An electric machine comprising: a first energy source;a second energy source;a stator, wherein the stator comprises: a first set of windings comprising AC field windings that are coupled to the first energy source; anda second set of windings comprising DC field windings that are coupled to the second energy source;a rotor; anda controller coupled to the first and second energy sources and configured to: control the first energy source to supply a first current to the first set of windings;control the second energy source to supply a second current to the second set of windings;detect an angular position of the rotor;detect the first current on the first set of windings;detect the second current on the second set of windings;determine an optimum phase shift angle of the first current relative to the second current that causes a corresponding maximum amount of torque to be generated on the rotor from the supplied first and second currents, the optimum phase shift angle of the first current being determined based on the angular position of the rotor, the detected first current, and the detected second current; andcontrol the first energy source based on the optimum phase shift angle to modify the first current supplied to the first set of windings. 2. The electric machine of claim 1 further comprising a shaft encoder coupled to the controller, wherein the shaft encoder is configured to detect the angular position of the rotor. 3. The electric machine of claim 1 wherein the first set of windings has a first number of poles (P1) and the second set of windings has a second number of poles (P2), wherein the second number of poles (P2) is less than the first number of poles (P1). 4. The electric machine of claim 3 wherein the rotor comprises salient poles free of windings, wherein the salient poles (P3) are determined by the equation: P3=(P1−P2)/2. 5. The electric machine of claim 3 wherein: P2≧4; andP1≧12. 6. The electric machine of claim 1 further comprising an inverter coupled to the first set of windings, the inverter configured to deliver the first current to the first set of windings. 7. The electric machine of claim 6 further comprising a compensation circuit coupled between the controller and the inverter, wherein the compensation circuit comprises a lead/lag circuit configured to compensate for varying gains and time lags of signals between the controller and the inverter. 8. The electric machine of claim 1 wherein the controller comprises a computer-readable storage medium therein, the computer-readable storage medium configured to store a plurality of optimum phase shift angle profiles thereon. 9. The electric machine of claim 8 wherein the controller is configured to select an optimum phase shift angle profile from the plurality of optimum phase shift angle profiles based on the angular position of the rotor, the detected first current of the first set of windings, and the detected second current of the second set of windings. 10. The electric machine of claim 1 wherein the rotor is one of a salient pole rotor and a round rotor. 11. A method for exciting an electrical machine having a plurality of windings, the method comprising: detecting a first current on a first set of stator windings, the first current supplied to the first set of stator windings via an inverter;detecting a second current on a second set of stator windings;detecting an angular position of a rotor;determining an optimum phase shift angle of the first current that would cause a corresponding maximum amount of torque to be generated on the rotor from the provided first and second currents, the optimum phase shift angle being determined based on the detected first current of the first set of stator windings, the detected second current of the second set of stator windings, and the detected angular position of the rotor; andmodifying a phase shift angle of the first current based on the determined optimum phase shift angle such that the first current of the inverter supplies the first current with the optimum phase shift angle to the first set of stator windings so as to generate the maximum torque on the rotor;wherein determining the optimum phase shift angle comprises accessing a lookup table having stored thereon a plurality of optimum phase shift angles in relation to the first current of the first set of stator windings, the second current of the second set of stator windings, and the angular position of the rotor. 12. The method of claim 11 wherein the plurality of optimum phase shift angles stored on the lookup table are determined via a plurality of static measurements, wherein the plurality of static measurements enable the determination maximum torque on the rotor at varying loads, varying currents on the first and second sets of stator windings, and varying angular positions of the rotor. 13. The method of claim 11 further comprising selecting a number of salient poles of the rotor (P3) based on a number of poles of the first winding (P1) and a number of poles of the second winding (P2), wherein P3=(P1−P2)/2. 14. A motor drive controller for applying current commands to an inverter to control current flow and terminal voltages in an electric machine, the motor drive controller configured to: detect an angular position of a rotor;detect a first current on a first set of windings of a stator, the first set of windings comprising AC field windings;detect a second current on a second set of windings of the stator, the second set of windings comprising DC field windings;determine an optimum phase shift angle of the first current that would cause a corresponding maximum amount of torque to be generated on the rotor from the first and second currents, the optimum phase shift angle being based on the detected angular position of the rotor, the detected first current on the first set of windings, and the detected second current on the second set of windings;generate an optimum phase shift angle demand based on the determined optimum phase shift angle; andinput the optimum phase shift angle demand to an inverter coupled to the first set of windings, wherein the inverter is configured to modify the phase shift angle of the first current, relative to the second current, on the first set of windings such that the maximum amount of torque on the rotor is obtained. 15. The motor drive controller of claim 14 wherein the motor drive controller is coupled to at least one of a shaft encoder and a resolver to determine the angular position of the rotor. 16. The motor drive controller of claim 14 wherein motor drive controller is coupled to current sensors configured to detect the first current on the first set of windings and the second current of the second set of windings. 17. The motor drive controller of claim 14 further comprising a computer-readable storage medium stored therein, the computer-readable storage medium having stored thereon a plurality of optimum phase shift angle profiles, wherein the optimum phase shift angle profiles are based on the angular position of the rotor, the first current of the first set of windings, and the second current of the second set of windings. 18. The motor drive controller of claim 14 wherein the motor drive controller is configured to detect an average AC current on the first set of windings and a DC current on the second set of windings. 19. The motor drive controller of claim 14 wherein the motor drive controller is coupled to a compensation circuit configured to compensate for varying gains and time lags of signals between the motor drive controller and the inverter. 20. An electric machine comprising: a first energy source;a second energy source;a stator, wherein the stator comprises: a first set of windings coupled to the first energy source; anda second set of windings coupled to the second energy source;a rotor; anda controller coupled to the first and second energy sources and configured to: control the first energy source to supply a first current to the first set of windings;control the second energy source to supply a second current to the second set of windings;detect an angular position of the rotor;detect the first current on the first set of windings;detect the second current on the second set of windings;determine an optimum phase shift angle of the first current relative to the second current that causes a corresponding maximum amount of torque to be generated on the rotor from the supplied first and second currents, the optimum phase shift angle of the first current being determined based on the angular position of the rotor, the detected first current, and the detected second current; andcontrol the first energy source based on the optimum phase shift angle to modify the first current supplied to the first set of windings;wherein the first set of windings has a first number of poles (P1) and the second set of windings has a second number of poles (P2), wherein the second number of poles (P2) is less than the first number of poles (P1); andwherein the rotor comprises salient poles free of windings, wherein the salient poles (P3) are determined by the equation: P3=(P1−P2)/2. 21. An electric machine comprising: a first energy source;a second energy source;a stator, wherein the stator comprises: a first set of windings coupled to the first energy source; anda second set of windings coupled to the second energy source;a rotor;a controller coupled to the first and second energy sources and configured to: control the first energy source to supply a first current to the first set of windings;control the second energy source to supply a second current to the second set of windings;detect an angular position of the rotor;detect the first current on the first set of windings;detect the second current on the second set of windings;determine an optimum phase shift angle of the first current relative to the second current that causes a corresponding maximum amount of torque to be generated on the rotor from the supplied first and second currents, the optimum phase shift angle of the first current being determined based on the angular position of the rotor, the detected first current, and the detected second current; andcontrol the first energy source based on the optimum phase shift angle to modify the first current supplied to the first set of windings;an inverter coupled to the first set of windings, the inverter configured to deliver the first current to the first set of windings; anda compensation circuit coupled between the controller and the inverter, wherein the compensation circuit comprises a lead/lag circuit configured to compensate for varying gains and time lags of signals between the controller and the inverter.