POWER EXTRACTOR FOR IMPEDANCE MATCHING

• US 20080122449A1
• Filed: 07/07/2007
• Published: 05/29/2008
• Est. Priority Date: 11/27/2006
• Status: Active Grant

• Current Assignee: Apparent Labs LLC
• Original Assignee: Xslent Energy Technologies, LLC
• Inventors: Besser, David A., Matan, Stefan
• Granted Patent: US 7,960,870 B2
• Time in Patent Office: Days
• US Class Current: 324/601
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

In some embodiments, a power extractor may operate such that the source impedance and the load impedance may have various values. The power extractor dynamically matches the impedance of the source and the load for the maximum transfer of power. The power extractor includes detection circuitry to continuously detect power changes, and is operated such that impedances of the power extractor between the source and load are dynamically changed in response to the detected power changes. The power extractor may then match an impedance of a power source to the impedance of a load. Other embodiments are described and claimed.

Claims

1. An apparatus comprising:

a first node and a second node; and

a power extractor to transfer power between the first and second nodes,

wherein the power extractor includes detection circuitry to detect power changes, and wherein in a first mode of operation, the power extractor is to be operated such that an input impedance of the power extractor is dynamically changed in response to the detected power changes to approach matching a first impedance outside the power extractor including an impedance of a power source coupled to the first node.

2. The apparatus of claim 1, wherein the input impedance of the power extractor equals the combined impedance of the power extractor and a load coupled to the second node as viewed from the first node.

3. The apparatus of claim 1, wherein in the first mode of operation, the power extractor is to be operated such that an output impedance of the power extractor is dynamically changed in response to the detected power changes so that under some load conditions the output impedance of the power extractor approaches matching a second impedance outside the power extractor including an impedance of the load coupled to the second node.

4. The apparatus of claim 3, wherein the output impedance of the power extractor equals the combined impedance of the power extractor and the power source as viewed from the second node.

5. The apparatus of claim 4, wherein the power extractor and the load are each outside the apparatus.

6. The apparatus of claim 3, further comprising a first connector between the power supply and the power extractor, and a second connector between the power extractor and the load, and wherein the first impedance includes an impedance of the first connector and the second impedance include an impedance of the second connector.

7. The apparatus of claim 6, wherein the impedances the first and second connectors are insignificant.

8. The apparatus of claim 1, wherein in practice the input impedance typically does not precisely match with the impedance of the power supply, and the output impedance typically does not precisely match the impedance of the load, but the dynamic changes lead toward close matching of the impedances.

9. The apparatus of claim 1, wherein when the power changes are zero and the power is at a global power maximum, the input and first impedances are essentially matched resulting in the power source providing a maximum power available given conditions beyond the control of the power extractor.

10. The apparatus of claim 1, wherein the power extractor includes circuitry to prevent the power from staying at a local power maximum at which one of the power changes is zero.

11. The apparatus of claim 1, wherein the power extractors at times operates in a second mode of operation, which is a protection mode in which the impedances are not matched.

12. The apparatus of claim 1, wherein the impedances are matched without regard to voltage or current of a power source at the first node and without regard to voltage or current of a load coupled to the second node, within certain parameters.

13. The apparatus of claim 1, wherein the detected power changes include a continuously detected instantaneous power slope.

14. The apparatus of claim 1, wherein the power extractor includes a first energy transfer circuit connected to first node to continuously transfer energy, a second energy transfer circuit connected to 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.

15. The apparatus of claim 13, wherein the first energy transfer circuit matches the input impedance of the power extractor with the first impedance.

16. The apparatus of claim 13, wherein the second energy transfer circuit matches an output impedance of the power extractor with a second impedance including a load coupled to the second node.

17. The apparatus of claim 13, wherein the power extractor includes switching circuitry 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.

18. The apparatus of claim 1, wherein the power extractor includes switching circuitry with a duty cycle that is at least partially dependent on the detected power changes and a magnitude of the transferred power is at least partially dependent on the duty cycle.

19. The apparatus of claim 13, wherein frequency of the switching circuits also controls efficiency of power transfer and thereby effects the amount of power transferred to the second node.

20. An apparatus comprising:

an input port and an output port;

power transfer circuitry to transfer power between the input and output ports; and

power change detection circuitry to continuously detect power changes, and wherein the apparatus is operated so as to seek having an input impedance of the power transfer circuitry match a first impedance outside the power transfer circuitry, wherein the first impedance includes an impedance of a power source.

21. The apparatus of claim 20, wherein the input impedance of the power transfer circuitry equals the combined impedance of the power transfer circuitry and a load coupled to the output port as viewed from the input port.

22. The apparatus of claim 21, wherein the power source and the power load are outside of the apparatus.

23. The apparatus of claim 21, wherein the power source and the power load are part of the apparatus.

24. The apparatus of claim 20, wherein the power source is part of the apparatus.

25. The apparatus of claim 20, further comprising a first connector between the power supply and the power transfer circuitry, and wherein the first impedance includes an impedance of the first connector.

26. The apparatus of claim 20, wherein in practice the input impedance typically does not precisely match with the first impedance.

27. The apparatus of claim 20, wherein the power transfer circuitry is operated to transfer power at a magnitude to cause the power source to approach providing a maximum power available given conditions beyond the control of the apparatus.

28. The apparatus of claim 20, wherein a load is coupled to the second port and the apparatus is operated so that under some load conditions the power transfer circuitry has an output impedance that seeks matching a second impedance outside the power transfer circuitry, wherein the second impedance includes an impedance of the load.

29. The apparatus of claim 20, wherein the power transfer circuitry includes a first energy transfer circuit connected to input node to continuously transfer energy, a second energy transfer circuit connected to 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.

30. An apparatus comprising:

a first node and a second node; and

a power extractor to transfer power between the first and second nodes,

wherein the power extractor includes detection circuitry to detect power changes, and wherein in a first mode of operation, the power extractor is to be operated such that input and output impedances of the power extractor between first and second nodes are dynamically changed in response to the detected power changes to seek matching the input impedance of the power extractor with a first impedance including an impedance of a power source coupled to the first node.

31. The apparatus of claim 30, wherein the power extractor is to approach matching the output impedance of the power extractor with a second impedance including an impedance of a load coupled to the second node.

32. The apparatus of claim 30, wherein the input impedance of the power extractor equals the combined impedance of the power extractor and the load as viewed from the first node, and the output impedance of the power extractor equals the combined impedance of the power extractor and the power supply as viewed from the second node.

33. A system comprising:

a power source coupled to a first node, and a load coupled to the second node; and

a power extractor to transfer power between the first and second nodes,

wherein the power extractor includes detection circuitry to detect power changes, and wherein in a first mode of operation, the power extractor is to be operated such that an input impedance of the power extractor is dynamically changed in response to the detected power changes to approach matching a first impedance including an impedance of the power source.

34. The system of claim 33, wherein under some load conditions, an output impedance of the power extractor is dynamically changed in response to the detected power changes to approach matching a second impedance including an impedance of the load.

35. The apparatus of claim 34, wherein the input impedance of the power extractor equals the combined impedance of the power extractor and the load as viewed from the first node, and the output impedance of the power extractor equals the combined impedance of the power extractor and the power supply as viewed from the second node.

36. The apparatus of claim 34, wherein in practice the input impedance typically does not precisely match with the impedance of the power supply, and the output impedance typically does not precisely match the impedance of the load, but the dynamic changes lead toward very close matching of the impedances.

38. The apparatus of claim 35, wherein the impedance of the power extractor equals the combined impedance of the power extractor and the load as viewed from the first node.

39. The apparatus of claim 35, wherein in practice the input impedance typically does not precisely match with the impedance of the power supply.

37. An apparatus comprising:

a first node and a second node; and

a power extractor to provide power between the first and second nodes,

wherein the power extractor is to be operated such that an impedance of the power extractor is dynamically changed for the purpose of matching impedances to achieve maximum power output of a power source outside the apparatus that is coupled to the first node given conditions beyond the control of the power extractor.

40. An apparatus comprising:

a first node and a second node; and

a power extractor to provide power between the first and second nodes,

wherein the power extractor is to be operated to dynamically match a first impedance of a power source outside of the apparatus coupled to the first node with a second impedance of a load coupled to the second node even as the first impedance changes and even as the second impedance changes.

41. The apparatus of claim 40, wherein the power source and load are each part of the apparatus.

42. The apparatus of claim 40, wherein the power source and load are each outside of the apparatus.