Power system

• US 20070159119A1
• Filed: 01/10/2006
• Published: 07/12/2007
• Est. Priority Date: 01/10/2006
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Adra, Rodwan, Hein, Bruce
• Application Number:
  US11/328,077
• Publication Number:
  US 20070159119A1
• Time in Patent Office: Days
• US Class Current: 318/56
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 7/16 for vehicles comprising converters between the power source and the motor
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2710/08 Electric propulsion units
• CPC Class Codes: B60W 30/18109 Braking
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A power system includes a power source with a rotary output member. The power system may also include an electric machine having a rotor and a stator. The rotor of the electric machine may be drivingly connected to the rotary output member of the power source. Additionally, the power system may include a sensor configured to provide a signal relating to at least one of a position of the rotor and a speed of the rotor. The power system may also include power-system controls configured to control electric current supply to the stator dependent upon the signal and control the power source dependent upon the signal.

Claims

1. A power system, comprising:

a power source having a rotary output member;

an electric machine, including

a rotor drivingly connected to the rotary output member of the power source, and

a stator;

a sensor configured to provide a signal relating to at least one of a position of the rotor and a speed of the rotor; and

power-system controls configured to

control electric current supply to the stator dependent upon the signal and

control the power source dependent upon the signal.

2. The power system of claim 1, wherein:

the sensor is configured to provide a signal relating to at least the position of the rotor; and

controlling electric current supply to the stator dependent upon the signal includes

selectively supplying alternating electric current to the stator, and

controlling the phase of the alternating electric current dependent upon the signal.

3. The power system of claim 1, wherein the power-system controls are further configured to

prior to controlling electric current supply to the stator dependent upon the signal, calibrate the signal by

while the rotor is rotating, controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor, and

calibrating the signal dependent upon the electrical activity induced in the stator by rotation of the rotor.

4. The power system of claim 3, wherein:

the sensor is configured such that signal relates to at least the position of the rotor; and

calibrating the signal includes calibrating the relationship between the signal and the position of the rotor.

5. The power system of claim 1, wherein:

the sensor is configured in a manner such that the signal relates to at least the position of the rotor; and

controlling electric current supply to the stator dependent upon the signal includes

selectively supplying alternating electric current to the stator, and

controlling the phase of the alternating electric current dependent upon the signal.

6. The power system of claim 1, wherein:

the sensor is configured such that the signal relates to at least the speed of the rotor; and

the power-system controls are further configured to utilize information relating to the electrical activity induced in the stator by rotation of the rotor to determine whether the signal correctly relates to the speed of the rotor.

7. The power system of claim 1, wherein:

the sensor is configured such that the signal also relates to the direction of rotation of the rotor; and

the power-system controls are further configured to utilize information relating to the electrical activity induced in the stator by rotation of the rotor to determine whether the signal correctly relates to the direction of rotation of the rotor.

8. The power system of claim 1, wherein the power-system controls are configured to control the power source dependent upon the signal.

9. The power system of claim 1, wherein the power system is part of a mobile machine.

10. The power system of claim 9, wherein:

the mobile machine includes one or more propulsion devices;

the electric machine is a first electric machine;

the power system further includes a second electric machine drivingly connected to one or more of the propulsion devices;

the power-system controls are further configured to

when the mobile machine is in motion, selectively cause the second electric machine to brake the motion of the mobile machine by operating as a generator, and

while causing the second electric machine to brake motion of the mobile machine, selectively cause the first electric machine to operate as a motor and drive the rotary output member of the power source.

11. A method of operating a power system having an electric machine, the electric machine having a rotor and a stator, and the power system also having a sensor configured to provide a signal relating to at least one of a position of the rotor and a speed of the rotor, the method comprising:

while the rotor is rotating, controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor; and

calibrating the signal dependent upon the electrical activity induced in the stator by rotation of the rotor.

12. The method of claim 11, wherein the electric machine is a permanent-magnet type electric machine.

13. The method of claim 12, wherein controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor includes supplying no electric current to the stator.

14. The method of claim 11, wherein controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor includes supplying no electric current to the stator.

15. The method of claim 11, further including:

subsequent to calibrating the signal, controlling electric current supply to the stator dependent upon the signal.

16. The method of claim 15, wherein controlling electric current supply to the stator dependent upon the signal includes

selectively supplying alternating electric current to the stator, and

controlling the phase of the alternating current dependent upon the signal.

17. The method of claim 15, wherein:

the power system further includes a power source having a rotary output member drivingly connected to the rotor of the electric machine; and

the method further includes controlling the power source dependent upon the signal.

18. The method of claim 17, wherein the power source is an internal combustion engine.

19. The method of claim 15, wherein:

the power system further includes a power source having a rotary output member drivingly connected to the rotor of the electric machine; and

controlling electric current supply to the stator dependent upon the signal includes selectively supplying electric current to the stator in such a manner to cause the rotor of the electric machine to drive the rotary output member of the power source.

20. The method of claim 11, wherein:

the signal relates to at least the position of the rotor; and

calibrating the signal dependent upon the electrical activity induced in the stator by rotation of the rotor includes calibrating the relationship between the signal and the position of the rotor.

21. The method of claim 11, wherein:

the sensor is configured such that the signal relates to at least the speed of the rotor; and

the method of operating the power system further includes utilizing information relating to the electrical activity induced in the stator by rotation of the rotor to determine whether the signal correctly relates to the speed of the rotor.

22. The method of claim 11, wherein:

the sensor is configured such that the signal also relates to the direction of rotation of the rotor; and

the method of operating the power system further includes utilizing information relating to the electrical activity induced in the stator by rotation of the rotor to determine whether the signal correctly relates to the direction of rotation of the rotor.

23. The method of claim 11, wherein the electric machine is a switched-reluctance type electric machine.

24. The method of claim 23, wherein controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor includes supplying a pulsing current to the stator.

25. The method of claim 11, wherein controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor includes supplying a pulsing current to the stator.

26. The method of claim 11, wherein:

the power system is part of a mobile machine;

the electric machine is a first electric machine;

the power system further includes a second electric machine;

the power system further includes a power source having a rotary output member drivingly connected to the rotor of the first electric machine;

wherein the method of operating the power system further includes

when the mobile machine is in motion, selectively causing the second electric machine to brake the motion of the mobile machine by operating as a generator; and

subsequent to calibrating the signal and while causing the second electric machine to brake motion of the mobile machine, selectively causing the first electric machine to operate as a motor and drive the rotary output member of the power source.

27. A mobile machine, comprising:

one or more propulsion devices configured to receive power and utilize that power to propel the mobile machine;

a power system configured to selectively provide power to the one or more propulsion devices to propel the mobile machine, the power system including

an internal combustion engine having a rotary output member;

a first electric machine drivingly connected to the rotary output member of the internal combustion engine;

a second electric machine;

a sensor configured to provide a signal relating to at least one of the position, speed, and direction of rotation of the rotary output member of the internal combustion engine;

power-system controls configured to

while the mobile machine is in motion, selectively cause the second electric machine to brake the mobile machine by receiving power from one or more of the propulsion devices and utilizing that power to generate electricity; and

while causing the second electric machine to brake the mobile machine, selectively operate the first electric machine as an electric motor to drive the rotary output member of the internal combustion engine, including controlling the first electric machine dependent upon the signal.

29. The mobile machine of claim 27, further including:

wherein the first electric machine includes a rotor and a stator; and

wherein controlling the first electric machine dependent upon the signal includes supplying current to the stator of the first electric machine dependent upon the signal.

30. The mobile machine of claim 29, wherein:

the power-system controls are further configured to

prior to supplying electric current to the stator of the first electric machine dependent upon the signal, calibrate the signal by

while the rotor of the first electric machine rotates, controlling electric current supply to the stator in a manner such that the position of the rotor may be determined from electrical activity induced in the stator by the rotation of the rotor, and

calibrating the signal dependent upon the electrical activity induced in the stator by rotation of the rotor.

31. The mobile machine of claim 27, wherein:

the first electric machine includes a rotor and a stator;

operating the first electric machine as a motor includes

supplying alternating electric current to the stator of the first electric machine, and

controlling the phase of the alternating electric current dependent upon the signal.

28. (canceled)