POWER EXTRACTOR DETECTING POWER AND VOLTAGE CHANGES

• US 20080191675A1
• Filed: 07/07/2007
• Published: 08/14/2008
• 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 9,130,390 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• 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 utilizes power transfer circuitry with analysis circuitry to detect a power slope and to control the magnitude of the current in response to the detected power slope. The power analysis circuitry may increase the current as long as the power slope shows an increase in power and may decrease the current as long as the power slope shows a decrease in power. The magnitude of the current is responsive to the duty cycle of the switching circuitry and to the detected power slope. Other embodiments are described and claimed.

Claims

1. An apparatus comprising:

a first node and a second node; and

a power extractor including;

power transfer circuitry to transfer power having a current between the first and second nodes; and

power change analysis circuitry to detect a power change and a voltage change and to at least partially control a magnitude of the power being transferred in response to the detected power change and voltage change.

2. The apparatus of claim 1, wherein the power extractor further includes:

switching circuitry to control the power transfer circuitry; and

switching control circuitry to control a duty cycle of the switching circuitry; and

wherein the power change analysis circuitry operates in different modes and wherein in an ordinary operating mode, under some conditions, the power analysis circuitry causes the power transfer circuitry to decrease the duty cycle if the power change and voltage change are both increasing or both decreasing, and to increase the duty cycle of the power transferred if the power change is decreasing and the voltage change is increasing or the power change is increasing and the voltage change is decreasing.

3. The apparatus of claim 2, 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.

4. The apparatus of claim 3, 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.

5. The apparatus of claim 3, wherein a frequency of operation of the switching circuitry is the dynamically adjusted to maximize efficiency of power transfer between the first and second nodes.

6. The apparatus of claim 3, wherein the first and second energy transfer circuits each includes an inductor and the intermediate energy transfer circuit includes capacitors.

7. The apparatus of claim 3, wherein the first, second, and intermediate energy transfer circuits each include at least one capacitor.

8. The apparatus of claim 1, wherein the power extractor further includes:

switching circuitry to control the power transfer circuitry; and

switching control circuitry to control a duty cycle of the switching circuitry; and

wherein the power change analysis circuitry operates in different modes and wherein in an ordinary operating mode, under some conditions, the power analysis circuitry causes the power transfer circuitry to increase the duty cycle if the power change and voltage change are both increasing or both decreasing, and to decrease the duty cycle of the power transferred if the power change is decreasing and the voltage change is increasing or the power change is increasing and the voltage change is decreasing.

9. The apparatus of claim 8, 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.

10. The apparatus of claim 9, 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.

11. The apparatus of claim 9, wherein the first and second energy transfer circuits each includes an inductor and the intermediate energy transfer circuit includes capacitors.

12. The apparatus of claim 9, wherein the first, second, and intermediate energy transfer circuits each include at least one capacitor.

13. The apparatus of claim 1, wherein the power analysis circuitry operates in different modes and wherein in an ordinary operating mode, the power analysis circuitry at least partially controls the magnitude of the current in response to the detected power change and voltage change, and in at least one other mode, the power analysis circuitry at least partially controls the magnitude of the current in response to at least one different factor.

14. The apparatus of claim 1, further comprising switching circuitry to interact with the power transfer circuitry and wherein the power analysis circuitry controls a duty cycle of the switching circuitry to at least partially control the magnitude of the current.

15. The apparatus of claim 14, wherein the power analysis circuitry also controls a frequency of the switching circuitry to at least partially control the magnitude of the current.

16. The apparatus of claim 14, further comprising a power source to provide power to the first node and power analysis circuitry seeks to control the switching circuitry to maximize power transfer through the power transfer circuitry given conditions beyond the control of the power analysis circuitry and given inefficiencies of the apparatus.

17. The apparatus of claim 16, wherein the power source is a photovoltaic power source and one of the conditions beyond the control of the power analysis circuitry is an amount of sunlight on the power source.

18. The apparatus of claim 16, wherein there is at least one intermediate node between the power supply and the first node.

19. The apparatus of claim 1, further comprising a load coupled to the second node.

20. The apparatus of claim 1, wherein the power change analysis circuitry is to detect a power slope and a voltage slope.

21. The apparatus of claim 1, wherein the power extractor operates to seek to match an input impedance of the power transfer circuitry with an output impedance of a power source.

22. An apparatus comprising:

a first node and a second node; and

power transfer circuitry to transfer power having a current between the first and second nodes; and

power analysis circuitry to detect a power change and to increase the current as long as the power change show an increase in power and to decrease the current as long as the power change shows a decrease in power.

23. The apparatus of claim 22, wherein the power analysis circuitry includes circuitry to smooth out sudden changes in the power change.

25. The apparatus of claim 23, wherein the power analysis circuitry operates in different modes and wherein in an ordinary operating mode, under some conditions, the power analysis circuitry causes the power transfer circuitry to decrease the current transferred if the power change and voltage change are both increasing or both decreasing, and to increase the current if the power change is decreasing and the voltage change is increasing or the power change is increasing and the voltage change is decreasing.

28. The apparatus of claim 23, wherein the power extractor operates in different modes and in an ordinary operating mode, the power analysis circuitry controls the duty cycle responsive to the detected power change and voltage change, and in another mode, which is protective mode, the power analysis circuitry controls the duty cycle responsive to at least one different factor.

29. The apparatus of claim 28, wherein in the at least one different factor includes detection of at least one limiting condition.

30. The apparatus of claim 29, wherein the limiting condition includes any one or more of the following:

excessive voltage, power, or current in the first node, power extractor, or second node;

too little voltage, power, or current in the first node, power extractor, or second node; and

a device limiting condition.

24. An apparatus comprising:

a first node and a second node; and

a power extractor including;

switching circuitry;

power transfer circuitry to transfer power having a current between the first and second nodes, wherein a magnitude of the current is at least partly responsive to a duty cycle of the switching circuitry; and

power analysis circuitry to detect a power change of the power and a voltage change and control the duty cycle responsive to the detected power change and voltage change.

26. The apparatus of claim 24, wherein the power analysis circuitry also controls a frequency of the switching circuitry to at least partially control the magnitude of the current.

27. The apparatus of claim 24, further including a source coupled to the first node and load coupled to the second node.