POWER EXTRACTOR WITH CONTROL LOOP

• US 20080191560A1
• Filed: 07/07/2007
• Published: 08/14/2008
• Est. Priority Date: 11/27/2006
• Status: Active Grant

• Current Assignee: Apparent Labs LLC, Rim Tec, Inc. (Kyriba Corp.)
• Original Assignee: Rim Tec, Inc. (Kyriba Corp.)
• Inventors: Besser, David A., Matan, Stefan
• Granted Patent: US 8,212,399 B2
• Time in Patent Office: Days
• US Class Current: 307/126
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

In some embodiments, a power extractor'"'"'s control loop detects changes in power and controls the duty cycle of the switching circuitry in response to the detected changes in power, thereby controlling the power transfer. The control loop may include a signal generator to control the duty cycle, and the frequency of the generated signal may be changed to optimize the energy transfer efficiency. The switching circuitry may control the rate at which circuits store and release the energy in response to the control signal and thereby seek to obtain a rate of storage and release that results in no detected changes in power. Other embodiments are described and claimed.

Claims

1. An apparatus comprising:

a first node and a second node; and

a power extractor including;

switching circuitry;

a control loop to control switching of the switching circuitry; and

power transfer circuitry to transfer power between the first and second nodes under control of the switching circuitry, and wherein when the power extractor operates in a first mode, the control loop controls the switching circuitry to cause the power transfer circuitry to transfer the power at a magnitude to cause a power source to approach providing a maximum power available given conditions beyond the control of the power extractor.

2. The apparatus of claim 1, wherein the control loop includes power change analysis circuitry to detect power changes and provide switching control signals in response thereto, and wherein in the first mode, the control loop controls the switching circuitry in response to the switching control signal.

3. The apparatus of claim 2, wherein the control loop further includes comparison circuitry to compare the switching control signal with a reference voltage and to provide a switching signal to control a duty cycle of the switching in response thereto.

4. The apparatus of claim 2, wherein the power change analysis circuitry includes power slope detection circuitry to detect a power slope of the power changes.

5. The apparatus of claim 4, wherein the power slope detection circuitry is to detect an instantaneous power slope.

6. The apparatus of claim 2, wherein the control loop includes circuitry to detect voltage changes corresponding to the power changes and wherein the control loop considers both the power changes and the voltage changes in determining the switching control signal.

7. The apparatus of claim 2, in which the power changes are changes of power in the one of the following:

the first node, the second node, or internal to the power extractor.

8. The apparatus of claim 1, wherein the control loop controls a frequency of the switching circuitry and the frequency influences efficiency of the power transfer circuitry.

9. The apparatus of claim 1, wherein the power extractor is a switching converter and the control loop controls a duty cycle of the switching circuitry.

10. The apparatus of claim 1, wherein the power source is part of the apparatus.

11. The apparatus of claim 1, wherein the power source is outside the apparatus.

12. The apparatus of claim 1, further comprising a first connector and a first additional node between the first node and the power extractor, and a second connector and a second additional node between the second node and a load coupled to the second node.

13. The apparatus of claim 1, wherein the power extractor is to transfer a maximum of the power provided by the power source given inefficiencies of the power extractor.

14. The apparatus of claim 1, wherein at times the power extractor operates in a second mode which is a protective mode in which the power transfer is regulated in response to at least one detected limiting condition.

15. The apparatus of claim 14, wherein under some conditions, the regulation involves preventing the power transfer altogether and under other conditions, the regulation involves reducing the power transfer below an otherwise available amount.

16. The apparatus of claim 14, wherein the control loop includes a processor that generates a bias signal, and wherein when the power extractor operates in the second mode, the magnitude of the power transferred is at least partially dependent on a value of the bias signal.

17. The apparatus of claim 1, wherein the control loop includes a processor that generates a bias signal, and wherein when the power extractor operates in the first mode, the magnitude of the power transferred is partially dependent on a value of the bias signal.

18. The apparatus of claim 1, wherein the power transfer circuitry includes a first energy transfer circuit connected to the first node to continuously transfer energy, a second energy transfer circuit connected to the second node to continuously transfer energy, and an intermediate energy transfer circuit connected between the first and second energy transfer circuits to discontinuously transfer energy between the first and second energy transfer circuits.

19. The apparatus of claim 18, wherein the switching circuitry is to modulate voltages at a third node between the first and intermediate energy transfer circuits, and at a fourth node between the intermediate and second energy transfer circuits.

20. The apparatus of claim 1, wherein during the first mode of operation, the magnitude of the power transfer is typically such that the power source provides very close to a maximum available power.

21. The apparatus of claim 1, wherein the switching circuitry, control loop, and power transfer circuitry are supported by a printed circuit board that is enclosed in a housing.

22. An apparatus comprising:

a first node and a second node; and

a power extractor including;

switching circuitry;

a control loop to control switching of the switching circuitry; and

power transfer circuitry to transfer power between the first and second nodes under control of the switching circuitry, and wherein when the power extractor operates in a first mode, the control loop controls the switching circuitry to seek to cause the power transfer circuitry to transfer the power at a magnitude to cause a power source to provide a maximum power available given conditions beyond the control of the power extractor.

23. The apparatus of claim 22, wherein the control loop includes power change analysis circuitry to detect power changes and provide a switching control signal in response thereto, and wherein in the first mode, the control loop controls the switching circuitry in response to the switching control signal.

24. The apparatus of claim 23, wherein the control loop further includes comparison circuitry to compare the switching control signal with a reference voltage and to provide a switching signal to control a duty cycle of the switching in response thereto.

25. The apparatus of claim 23, wherein the power change analysis circuitry includes power slope detection circuitry to detect a power slope of the power changes.

26. The apparatus of claim 25, wherein the power slope detection circuitry is to detect an instantaneous power slope.

27. The apparatus of claim 23, wherein the control loop includes circuitry to detect a voltage changes corresponding to the power changes and wherein the control loop considers both the power changes and the voltage changes in determining the switching control signal.

28. A system comprising:

a first node and a second node;

power transfer circuitry to transfer power between the first and second nodes;

switching circuitry to control power transfer between the first and second nodes, and a control loop including circuitry to detect power changes and to control a duty cycle of the switching circuitry in response to the detected power changes to thereby control the power transfer circuitry.

29. The system of claim 28, wherein the circuitry to detect power changes is at distance of more than one meter from the power transfer circuitry.

30. The system of claim 28, wherein the circuitry to detect power changes and the power transfer circuitry are in a common container.

31. The system of claim 28, wherein the power changes are determined through measurement of signals in at least one of following positions:

in the first node, in the power transfer circuitry, or in the second node.

32. The system of claim 28, wherein the control loop includes a signal generator to generate a signal to be used in the controlling of the duty cycle.

33. The system of claim 28, further comprising a power source coupled to the first node.

34. The system of claim 28, further comprising a load coupled to the second node.

35. The system of claim 28, wherein the power transfer circuitry includes a first energy transfer circuit connected to the first node to continuously transfer energy, a second energy transfer circuit connected to the second node to continuously transfer energy, and an intermediate energy transfer circuit connected between the first and second energy transfer circuits to discontinuously transfer energy between the first and second energy transfer circuits.

36. The system of claim 35, wherein the switching circuitry is to modulate voltages at a third node between the first and intermediate energy transfer circuits, and at a fourth node between the intermediate and second energy transfer circuits.

37. A method comprising:

transferring power at a first node through power transfer circuitry to a second node;

detecting power changes;

in a first mode of operation, creating a switching control signal in response to the detected power changes;

generating a switching signal to control switches in response to the switching control signal; and

modulating the power transfer circuitry through opening and closing of the switches.

38. The method of claim 37, wherein the switching signal is created by comparing the switching control signal with a reference signal.

39. The method of claim 37, further comprising generating a bias signal that is used in creating the switching control signal.

40. The method of claim 37, wherein the bias signal is used in creating the switching control signal in the first mode and in a protection mode.

41. The method of claim 37, wherein the modulating of the power transfer circuitry is power provided from a power supply coupled to the first node approaches a maximum available amount given conditions beyond the control of the power transfer circuitry.