Method, apparatus and article for load stabilization

• US 20060119306A1
• Filed: 12/03/2004
• Published: 06/08/2006
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG), DaimlerChrysler AG (Mercedes-Benz Group AG)
• Original Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Inventors: Hampo, Richard J., Nallapa, Venkatapathi R., Prenner, Franz
• Granted Patent: US 7,348,750 B2
• Time in Patent Office: Days
• US Class Current: 318/623
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A system, method, and article for protecting a power source for a machine from sudden changes in load. In one embodiment, energy is wasted in a winding of a motor in response to a decrease in a load presented to the power source.

Claims

1. A system for stabilizing a load presented by a machine, the system comprising:

means for determining whether load stabilization is desired; and

means for stabilizing the load by wasting energy in at least one winding of the machine communicatively coupled to the means for determining whether load stabilization is desired.

2. The system of claim 1, further comprising:

alternative means for stabilizing the load communicatively coupled to the means for determining whether load stabilization is desired.

3. The system of claim 1 wherein the load comprises a load presented to power source selected from the group consisting of a fuel cell stack, a battery array, a super-capacitor array and an ultra-capacitor array.

4. The system of claim 1 wherein the means for determining whether load stabilization is desired comprises a load stabilization control subsystem and the means for stabilizing the load by wasting energy in at least one winding of the machine comprises a current control subsystem.

5. The system of claim 1 wherein the means for determining whether load stabilization is desired determines whether load stabilization is desired based at least in part on an indication of a change in the load presented by the machine.

6. The system of claim 5 wherein the indication comprises an estimated torque of a rotor in the machine.

7. The system of claim 5 wherein the indication comprises a level of a throttle control signal.

8. The system of claim 5 wherein the indication comprises a measured change in the load.

9. The system of claim 5 wherein the indication comprises an estimated change in the load.

10. The system of claim 5 wherein the indication comprises a combination of a measured change in the load and an estimated change in the load.

11. The system of claim 1 wherein the means for determining whether load stabilization is desired is configured to monitor a signal corresponding to an operational mode of the machine and to generate a control signal to adjust a flux current based at least in part on the monitored signal corresponding to the operational mode of the machine.

12. The system of claim 1 wherein the means for determining whether load stabilization is desired is configured to monitor a signal corresponding to a temperature and to selectively generate a control signal to adjust a flux current based at least in part on the monitored signal corresponding to the temperature.

13. The system of claim 1 wherein the means for determining whether load stabilization is desired is configured to calculate a capacity for increasing a flux current and to calculate a desired increase in the flux current, and to generate a control signal to adjust the flux current based in part on a comparison of the calculated capacity for increasing the flux current and the calculated desired increase in the flux current.

14. The system of claim 1 wherein the means for determining whether load stabilization is desired is configured to generate a control signal to avoid an oscillating load condition.

15. The system of claim 1 wherein the means for determining whether load stabilization is desired is configured to calculate an increase in a flux current to achieve a desired amount of energy wasting, and to generate a control signal to adjust the flux current based in part on a comparison of the calculated increase in the flux current to a threshold value.

16. The system of claim 1 wherein the means for determining whether load stabilization is desired comprises:

a proportional and integral controller; and

a comparator.

17. An alternating current machine, comprising:

a rotor; and

a control system for controlling the alternating current machine, the control system comprising;

a current control subsystem to generate current control signals to control a flux current provided to at least one winding of the machine; and

a load stabilization control subsystem communicatively coupled to the current control subsystem, wherein the load stabilization control subsystem is configured to;

monitor a signal corresponding to a load presented by the machine; and

selectively generate a control signal to adjust the flux current provided to the at least one winding based at least in part on the monitored signal.

18. A control system for a machine, comprising:

a first bi-directional limiter comprising;

a first input to receive a signal corresponding to a desired energy-wasting component of a flux current;

a second input to receive a signal corresponding to a lower limit on the energy-wasting component of the flux current;

a third input to receive a signal corresponding to an upper limit on the energy-wasting component of the flux current; and

a first output; and

a proportional and integral regulator comprising;

a fourth input electrically coupled to the first output;

a fifth input to receive a signal for controlling a proportional gain of the proportional and integral regulator;

a sixth input to receive a signal for controlling an integral gain of the proportional and integral regulator; and

a second output.

19. The control system of claim 18 wherein the proportional and integral regulator further comprises a seventh input to receive a signal for limiting the output of the proportional and integral controller.

20. The control system of claim 19, further comprising:

a first signal combiner comprising;

an eighth input to receive a signal corresponding to a maximum flux current;

a ninth input to receive a signal corresponding to a mode of operation of the machine; and

a third output electrically coupled to the seventh input.

21. The control system of claim 18, further comprising:

a second bi-directional limiter comprising;

a seventh input electrically coupled to the second output;

a third output;

an eighth input to receive a signal for controlling a minimum value of the third output; and

a ninth input to receive a signal for controlling a maximum value of the third output.

22. The control system of claim 21, further comprising:

a first signal combiner comprising;

a tenth input to receive a signal corresponding to a maximum flux current;

an eleventh input to receive a signal corresponding to a mode of operation of the machine; and

a fourth output electrically coupled to the ninth input.

23. The control system of claim 18, further comprising:

a first signal combiner comprising;

a seventh input to receive a signal corresponding to a speed of a rotor of the machine;

an eighth input to receive a signal corresponding to an estimated torque of the rotor; and

a third output;

a first low-pass filter comprising;

a ninth input electrically coupled to the third output;

a tenth input to receive a signal corresponding to a first time constant; and

a fourth output; and

an adder comprising;

an eleventh input electrically coupled to the fourth output;

a twelfth input to receive a signal corresponding to a commanded level of energy wasting;

a thirteenth input to receive a signal corresponding to a loss of the machine; and

a fifth output electrically coupled to the first input.

24. The control system of claim 18, further comprising:

a first low-pass filter comprising;

a seventh input electrically coupled to the first input;

an eighth input to receive a first time constant; and

a third output.

25. The control system of claim 24, further comprising:

a comparator comprising;

a ninth input electrically coupled to the third output;

a tenth input to receive a threshold value; and

a fourth output.

26. The control system of claim 25, further comprising:

a logical gate comprising;

an eleventh input electrically coupled to the fourth output;

a twelfth input to receive a signal corresponding to an operational mode of the machine; and

a fifth output.

27. The control system of claim 26 wherein the logical gate comprises an OR gate.

28. The control system of claim 26 wherein the logical gate comprises a NAND gate.

29. A control system for a machine, comprising:

a first signal combiner comprising;

a first input to receive a signal corresponding to a speed of the machine;

a second input to receive a signal corresponding to an estimated torque of the machine; and

a first output;

a first low-pass filter comprising;

a third input electrically coupled to the first output;

a fourth input to receive a signal corresponding to a first time constant; and

a second output;

an adder comprising;

a fifth input electrically coupled to the second output;

a sixth input to receive a signal corresponding to a loss of the machine;

a seventh input to receive a signal corresponding to a commanded energy-wasting flux current; and

a third output;

a first bi-directional limiter comprising;

an eighth input electrically coupled to the third output;

a fourth output;

a ninth input to receive a signal corresponding to an upper limit on the fourth output; and

a tenth input to receive a signal corresponding to a lower limit on the fourth output;

a proportional and integral regulator comprising;

an eleventh input electrically coupled to the fourth output;

a fifth output;

a twelfth input to receive a signal for controlling a proportional gain of the proportional and integral regulator; and

a thirteenth input to receive a signal for controlling an integral gain of the proportional and integral regulator; and

a second bi-directional limiter comprising;

a fourteenth input electrically coupled to the fifth output;

a sixth output;

a fifteenth input to receive a signal corresponding to a lower limit on the sixth output; and

a sixteenth input corresponding to an upper limit on the sixth output.

30. A method of stabilizing a load presented by a machine, the method comprising:

receiving an indication that load stabilization is desired; and

selectively wasting energy in at least one winding of the machine based at least in part on the received indication that load stabilization is desired.

31. The method of claim 30 wherein selectively wasting energy in at least one winding of the machine comprises controlling a flux current provided to the at least one winding of the machine.

32. The method of claim 30 wherein the load comprises a load presented to a power source selected from the group consisting of a fuel cell stack, a battery array, a super-capacitor array and an ultra-capacitor array.

33. The method of claim 30 wherein receiving an indication comprises receiving a signal corresponding to an estimated torque of a rotor in the machine.

34. The method of claim 30 wherein receiving an indication comprises receiving a throttle control signal.

35. The method of claim 30 wherein receiving an indication comprises receiving a signal corresponding to a measured change in the load.

36. The method of claim 30 wherein receiving an indication comprises receiving a signal corresponding to an estimated change in the load.

37. The method of claim 30, further comprising:

monitoring an operational mode of the machine; and

controlling a flux current provided to the at least one winding of the machine based at least in part on the monitoring of the operational mode.

38. The method of claim 37 wherein monitoring an operational mode comprises monitoring a control signal.

39. The method of claim 30, further comprising:

monitoring an operational condition of the machine; and

controlling a flux current provided to the at least one winding of the machine based at least in part on the monitoring of the operational condition.

40. The method of claim 39 wherein monitoring an operational condition comprises monitoring a sensor.

41. The method of claim 30, further comprising:

calculating a desired increase in a flux current;

calculating a capacity for increasing the flux current; and

controlling the flux current provided to the at least one winding of the machine based at least in part on the calculated desired increase in the flux current and the calculated capacity for increasing the flux current.

42. The method of claim 30, further comprising:

controlling a flux current provided to the at least one winding of the machine based at least in part on a threshold value.

43. The method of claim 42 wherein the threshold value corresponds to a minimum amount of energy wasting.

44. The method of claim 42 wherein the threshold value corresponds to a maximum amount of energy wasting.

45. The method of claim 42 wherein the threshold value corresponds to a minimum amount of flux current.

46. The method of claim 42 wherein the threshold value corresponds to a maximum amount of flux current.

47. A computer readable medium storing instructions for causing a control system to facilitate stabilization of a load presented by a machine by:

determining whether load stabilization is desired; and

controlling a flux current provided to at least one winding of the machine based at least in part on the determination.