Conduction angle control of a switched reluctance generator

• US 20090001911A1
• Filed: 06/29/2007
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Tate, William James, Kayikci, Ekrem
• Granted Patent: US 7,755,308 B2
• Time in Patent Office: Days
• US Class Current: 318/254.100
• CPC Class Codes: H02P 25/0925 wherein the converter comprises only one switch per phase
• CPC Class Codes: H02P 6/15 Controlling commutation time
• CPC Class Codes: H02P 9/02 Details

Abstract

A control system is disclosed. The control system has a switched reluctance generator coupled to provide electrical power through a DC bus to a motor. The control system also has a controller in communication with the switched reluctance generator, the motor, and the DC bus. The controller is configured to receive an indication of an amount torque or power required by the motor, determine a conduction angle of the switched reluctance generator based on the amount of torque or power required by the motor; and energize the DC bus with the electrical power provided by the switched reluctance generator based on the optimal conduction angle.

Claims

1. A control system, comprising:

a switched reluctance generator coupled to provide electrical power through a DC bus to a motor; and

a controller in communication with the switched reluctance generator, the motor, and the DC bus, the controller being configured to;

receive an indication of an amount torque or power required by the motor;

determine a conduction angle of the switched reluctance generator based on the amount of torque or power required by the motor; and

energize the DC bus with the electrical power provided by the switched reluctance generator based on the conduction angle.

2. The control system of claim 1, wherein determining a conduction angle includes:

receiving an indication of a rotational speed of the motor;

determining an amount of power required by the motor based on the rotational speed of the motor and the amount of torque required by the motor; and

determining a rated conduction angle of the switched reluctance generator for the amount of power required by the motor.

3. The control system of claim 2, wherein determining a conduction angle further includes determining a deviation from the rated conduction angle of the switched reluctance generator based on a difference between the amount of torque or power required by the motor and a rated amount of power for the motor, and a difference between the current rotational speed of the motor and a rated rotational speed of the motor.

4. The control system of claim 3, wherein determining a conduction angle further includes adding the rated conduction angle of the switched reluctance generator to the deviation from the rated conduction angle of the switched reluctance generator.

5. The control system of claim 1, wherein energizing the DC bus includes providing the electrical power to an energy storage device contained in the DC bus.

6. The control system of claim 5, wherein the motor is configured to draw the electrical power from the energy storage device and produce a mechanical power output in response to the amount of torque required.

7. The control system of claim 1, further including:

a power converter coupled to at least one phase coil of the switched reluctance generator; and

at least one capacitor coupled to the power converter,

wherein energizing the DC bus includes selectively switching the power converter to allow an electrical current stored in the at least one phase coil to pass to and energize the at least one capacitor.

8. The control system of claim 7, wherein the power converter includes least one transistor, and switching the power converter includes providing a voltage signal to a gate of the transistor.

9. A method of transferring power, comprising:

providing electrical power from a switched reluctance generator through a DC bus to a motor;

receiving an indication of an amount torque or power required by the motor;

determining a conduction angle of the switched reluctance generator based on the amount of torque or power required by the motor; and

energizing the DC bus with the electrical power provided by the switched reluctance generator based on the conduction angle.

10. The method of claim 9, wherein determining a conduction angle includes:

receiving an indication of a rotational speed of the motor;

determining an amount power required by the motor based on the rotational speed of the motor and the amount of torque required by the motor; and

determining a rated conduction angle of the switched reluctance generator for the amount of power required by the motor.

11. The method of claim 10, wherein determining a conduction angle further includes determining a deviation from the rated conduction angle of the switched reluctance generator based on a difference between the amount of power required by the motor and a rated amount of power for the motor, and a difference between the current rotational speed of the motor and a rated rotational speed of the motor.

12. The method of claim 11, wherein determining a conduction angle further includes adding the rated conduction angle of the switched reluctance generator to the deviation from the rated conduction angle of the switched reluctance generator.

13. The method of claim 9, wherein energizing the DC bus includes providing the electrical power to an energy storage device contained in the DC bus.

14. The method of claim 13, further including:

drawing, by the motor, the electrical power from the energy storage device; and

producing, by the motor, a mechanical power output in response to the amount of torque or power required by the motor.

15. A machine, comprising:

a combustion engine configured to power operations of the machine;

a motor arranged to move the machine;

a switched reluctance generator coupled to receive a mechanical power input from the combustion engine, and provide electrical power through a DC bus to the motor; and

a controller in communication with the switched reluctance generator, the motor, and the DC bus, the controller being configured to;

receive an indication of an amount torque or power required by the motor;

determine a conduction angle of the switched reluctance generator based on the amount of torque or power required by the motor; and

energize the DC bus with the electrical power provided by the switched reluctance generator based on the conduction angle.

16. The machine of claim 15, wherein determining a conduction angle includes:

receiving an indication of a rotational speed of the motor;

determining an amount power required by the motor based on the rotational speed of the motor and the amount of torque required by the motor; and

determining a rated conduction angle of the switched reluctance generator for the amount of power required by the motor.

17. The machine of claim 15, wherein determining a conduction angle further includes determining a deviation from the rated conduction angle of the switched reluctance generator based on a difference between the amount of power required by the motor and a rated amount of power for the motor, and a difference between the current rotational speed of the motor and a rated rotational speed of the motor.

18. The machine of claim 17, wherein determining a conduction angle further includes adding the rated conduction angle of the switched reluctance generator to the deviation from the rated conduction angle of the switched reluctance generator.

19. The machine of claim 15, wherein energizing the DC bus includes providing the electrical power to a storage element contained in the DC bus.

20. The machine of claim 19, wherein the motor is configured to draw the electrical power from the storage element and produce a mechanical power output in response to the amount of torque required.