Power extractor detecting a power change

• US 7,839,025 B2
• Filed: 07/07/2007
• Issued: 11/23/2010
• 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
• Primary Examiner(s): Fureman; Jared J
• Assistant Examiner(s): Amrany; Adi
• Application Number:
  US11/774,562
• Publication Number:
  US 20080179949A1
• Time in Patent Office: 1,235 Days
• Field of Search: 307/99
• US Class Current: 307/99
• 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
• 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 operates in a manner to obtain more power transferred from the source to the load than typically is obtained without the power extractor. The power extractor may perform universal impedance matching as this is seen from either the power source or the load. This impedance matching allows the power source to provide an optimal amount of power transfer that is greater than would be able without the impedance matching. The power extractor transfers power between two nodes and may be operated so that the power transferred is dependent on continuously detected power changes, and the voltage and current at the first and second nodes are unregulated. Other embodiments are described and claimed.

Claims

1. An apparatus comprising:

a first node to supply power received from a power source, the first node having an associated first operating impedance;

a second node to receive power to be supplied to a load separate from the power source, the second node having an associated second operating impedance; and

a power extractor to transfer power from the first node to the second node, wherein the power extractor is operated such that an input impedance of the power extractor, in relation to the first operating impedance, and an output impedance of the power extractor, in relation to the second operating impedance, are each to be adjusted based, at least in part, on both the load and the source, including

a continuously detected power change and power level from the source at the first node,

a voltage level from the load at the second node, and

an amount of current the second node is capable of drawing, the amount of current determined based, at least in part, on the voltage level at the second node and an amount of power the load is capable of receiving from the second node,

wherein voltage and current at the first node are not fixed and the power transferred to the second node is unregulated with respect to the load.

2. The apparatus of claim 1, wherein

the input impedance of the power extractor is adjusted to match the first operating impedance if the amount of power the load is capable of receiving is greater than the power level detected from the source at the first node,

the output impedance of the power extractor is adjusted to match the second operating impedance if the amount of power the load is capable of receiving is less than the power level detected from the source at the first node, and

the input and output impedance of the power extractor are adjusted to match the second operating impedance if the amount of power the load is capable of receiving is equal to the power level detected from the source at the first node.

3. The apparatus of claim 1, wherein the detected power change at the first node includes an instantaneous power slope.

4. The apparatus of claim 1, wherein the adjustment to the input and output impedance of the power extractor is further based on a voltage change concurrent with the continuously detected power change at the first node.

5. The apparatus of claim 1, wherein the power extractor is to transfer power to the second node at a magnitude that causes the power source to approach providing a maximum power available given conditions beyond the control of the power extractor, and the magnitude of the power transferred is partially dependent on the maximum power available.

6. The apparatus of claim 5, wherein the power extractor is to transfer a maximum of the power provided by the power source given inefficiencies of the power extractor.

7. The apparatus of claim 6, wherein the power extractor typically does not actually achieve having an absolute maximum power from the power source given the conditions beyond the control of the power extractor, and typically does not actually achieve transferring an absolute maximum of the power provided by the power source given inefficiencies of the power extractor.

8. 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.

9. The apparatus of claim 8, 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.

10. The apparatus of claim 9, wherein the at least one detected limiting condition includes 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.

11. The apparatus of claim 10, further comprising a temperature sensor to sense a temperature of a load coupled to the second node, wherein an excessive sensed temperature is an example of a device limiting condition.

12. The apparatus of claim 1, wherein when the power extractor operates in the first mode, the magnitude of the power transferred is partially dependent on a value of a bias signal.

13. The apparatus of claim 1, wherein the power extractor adaptively matches impedances between the power source and a combination of the power extractor and the load.

14. The apparatus of claim 1, wherein the power extractor 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.

15. The apparatus of claim 14, wherein the first and second energy transfer circuits are multiphase bisector energy transfer circuits to cause the multiphase bisector energy transfer and to interface with the discontinuous intermediate energy transfer circuit.

16. The apparatus of claim 14, 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.

17. The apparatus of claim 14, 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.

18. The apparatus of claim 14, wherein the first and second energy transfer circuits each includes an inductor and the intermediate energy transfer circuit includes capacitors.

19. The apparatus of claim 14, wherein the first, second, and intermediate energy transfer circuits each include at least one capacitor.

20. 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 change and the magnitude of the transferred power is at least partially dependent on the duty cycle.

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

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

analysis circuitry to provide a switching control signal; and

switching circuitry to control a magnitude of the transferred power in response to the switching control signal.

22. The apparatus of claim 21, wherein the analysis circuitry includes power change detection circuitry to continuously determine the power change and provide a power change indication signal indicative of the power change, and wherein the switching control signal is the same as the power change indication signal.

23. The apparatus of claim 21, wherein the analysis circuitry includes:

power change detection circuitry to determine the power change and provide a power change indication signal indicative of the power change;

processing circuitry to create a bias signal in at least one mode of operation;

scaling circuitry to scale the bias signal; and

combining circuitry to combine the scaled bias signal with the power change indication signal to create the switching control signal in the at least one mode of operation.

24. The apparatus of claim 1, wherein the power extractor is a switching converter.

25. The apparatus of claim 1, wherein the power source includes at least one of the following types of power sources:

photovoltaic, wind power, a hydrogen power generator, a battery, piezo-electric, hydro-electric, thermal couple, mechanical deformation, and other stable power sources, and other unstable power sources.

26. A system comprising:

a power source coupled to a first node having a first impedance;

a load coupled to a second node having a second impedance; and

a power extractor to transfer power from the first node to the second node, wherein the power extractor is operated such that an input impedance of the power extractor, in relation to the first impedance, and an output impedance of the power extractor, in relation to the second impedance, are each to be adjusted based, at least in part, on both the load and the source, including

a continuously detected power change and power level from the source at the first node,

a voltage level from the load at the second node, and

an amount of current the second node is capable of drawing, the amount of current determined based, at least in part, on the voltage level at the second node and an amount of power the load is capable of receiving from the second node,

wherein voltage and current at the first node are not fixed and the power transferred to the second node is unregulated with respect to the load.

27. The system of claim 26, wherein

the input impedance of the power extractor is adjusted to match the first operating impedance if the amount of power the load is capable of receiving is greater than the power level detected from the source at the first node,

the output impedance of the power extractor is adjusted to match the second operating impedance if the amount of power the load is capable of receiving is less than the power level detected from the source at the first node, and

the input and output impedance of the power extractor are adjusted to match the second operating impedance if the amount of power the load is capable of receiving is equal to the power level detected from the source at the first node.

28. The system of claim 26, wherein the power extractor includes a processor to detect the changes and to do statistical analysis of data gathered.

29. The system of claim 26, wherein the power source includes sub-power sources and the load includes sub-loads.

30. The system of claim 26, further comprising additional power sources and additional power extractors, and further comprising a central station to receive information from the power extractors.

31. The system of claim 26, wherein the detected power change at the first node includes an instantaneous power slope.

32. The system of claim 26, wherein the adjustment to the input and output impedance of the power extractor is further based on a voltage change concurrent with the continuously detected power change at the first node.