WIRELESS ENERGY TRANSFER USING VARIABLE SIZE RESONATORS AND SYSTEM MONITORING

• US 20130278073A1
• Filed: 06/21/2013
• Published: 10/24/2013
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Kurs, Andre B., Karalis, Aristeidis, Kesler, Morris P., Campanella, Andrew J., Hall, Katherine L., Kulikowski, Konrad J., Soljacic, Marin
• Granted Patent: US 9,596,005 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A variable shape magnetic resonator includes an array of at least two resonators each being of a substantially different shapes and at least one power and control circuit configured to selectively connect to and energize at least one of the resonators.

Claims

1. A wireless power transfer system with at least one adjustable magnetic resonator comprising:

a first magnetic resonator with a plurality of differently sized inductive elements;

at least one power and control circuit configured to selectively connect to at least one of the plurality of differently sized inductive elements;

one or more additional magnetic resonators separated from the first magnetic resonator; and

measurement circuitry to measure at least one parameter of a wireless power transfer between the first magnetic resonator and the one or more additional magnetic resonators, wherein one or more connections between the plurality of differently sized inductive elements and the at least one power and control circuit are configured to change an effective size of the first magnetic resonator according to the at least one parameter measured by the measurement circuitry.

2. The system of claim 1, wherein the first magnetic resonator is a source resonator and the power and control circuit is configured to energize at least one of the differently sized inductive elements.

3. The system of claim 1, wherein the first magnetic resonator is a device resonator and the power and control circuit is configured to receive energy from one or more of the plurality of differently sized inductive elements.

4. The system of claim 1, wherein the first magnetic resonator is a repeater resonator and the power and control circuit is configured to energize one or more of the plurality of differently sized inductive elements.

5. The system of claim 1, wherein the first magnetic resonator is a repeater resonator and the power and control circuit is configured to receive energy from one or more of the plurality of differently sized inductive elements.

6. The system of claim 1, wherein the first magnetic resonator is configurable to be a source resonator.

7. The system of claim 1, wherein the at least one parameter includes a distance between the first magnetic resonator and at least one of the one or more additional magnetic resonators.

8. The system of claim 1, wherein the at least one parameter includes a power transfer efficiency between the first magnetic resonator and at least one of the one or more additional magnetic resonators.

9. The system of claim 1, wherein the at least one parameter includes an input impedance of at least one of the first magnetic resonator and the one or more additional magnetic resonators.

10. The system of claim 1, wherein the at least one parameter includes an impedance of a coupled system including the first magnetic resonator and the one or more additional magnetic resonators.

11. The system of claim 1, wherein the at least one parameter includes a voltage measurement in the at least one power and control circuit.

12. The system of claim 1, wherein the at least one parameter includes a current measurement in the at least one power and control circuit.

13. The system of claim 1, wherein the at least one parameter includes a phase measurement in the at least one power and control circuit.

14. The system of claim 7, wherein an effective size of the plurality of different sized inductive elements of the first magnetic resonator is proportional to a separation distance between the first magnetic resonator and at least one of the one or more additional magnetic resonators.

15. The system of claim 8, wherein the effective size of the plurality of different sized inductive elements is selected to maximize an efficiency of power transfer between the first magnetic resonator and the one or more additional magnetic resonators when energized.

16. The system of claim 15, further comprising a communication link between a source including the first magnetic resonator and a device including the one or more additional magnetic resonators.

17. The system of claim 16, wherein the at least one parameter is exchanged between the source and the device using the communication link.

18. The system of claim 1, wherein the connections between said power control circuit and said differently sized inductive elements of the said first magnetic resonator are configured by open circuiting portions of said inductive elements.

19. The system of claim 1, wherein a connection between the at least one power and control circuit and the plurality of differently sized inductive elements is configured by short circuiting one or more portions of the plurality of differently sized inductive elements.

20. The system of claim 1, wherein a connection between the at least one power and control circuit and the plurality of differently sized inductive elements is configured by switching out portions of the inductive element circuit.

21. A wireless power transfer system with an adjustable effective size magnetic resonator comprising:

a source with an adjustable effective size resonator including a plurality of differently sized source magnetic resonators and at least one power and control circuit configured to selectively connect to at least one of the plurality of differently sized source magnetic resonators;

a device separated from the source, the device having at least one device magnetic resonator; and

measurement circuitry to measure at least one parameter of a wireless power transfer between the source and the device, wherein one or more connections between the plurality of differently sized source magnetic resonators and the at least one power control circuit are configured to change an effective size of the adjustable effective size resonator according to the at least one parameter measured by the measurement circuitry.

22. The system of claim 21, wherein the adjustable effective size magnetic resonator has a quality factor Q greater than 10.

23. The system of claim 21, wherein the at least one parameter includes a separation distance between the source and the device.

24. The system of claim 21, wherein the at least one parameter includes an efficiency of the wireless power transfer between the source and the device.

25. The system of claim 21, wherein the at least one parameter includes a characteristic impedance of the adjustable effective size magnetic resonator.

26. The system of claim 21, wherein the at least one parameter includes a voltage on the adjustable effective size magnetic resonator.

27. The system of claim 21, wherein the at least one parameter includes a current on the adjustable effective size magnetic resonator.

28. The system of claim 23, wherein a size of the adjustable effective size magnetic resonator is adjusted proportionally to a separation distance between the source and the device.

29. The system of claim 24, wherein a size of the adjustable effective size magnetic resonator is selected to maximize an efficiency of the wireless power transfer between the source and the device.

30. The system of claim 29, further comprising a communication link between the source and the device.

31. An adjustable effective size resonator for wireless power transfer comprising:

a magnetic resonator including a plurality of differently sized inductive elements;

at least one power and control circuit configured to selectively connect to and energize at least one of the plurality of differently sized inductive elements; and

measurement circuitry to measure at least one electrical parameter of the magnetic resonator, wherein one or more connections between the plurality of differently sized inductive elements and the at least one power and control circuit are configured according to the at least one electrical parameter.

32. The device of claim 31, wherein the at least one electrical parameter includes a characteristic impedance of one or more of the plurality of differently sized inductive elements.

33. The device of claim 31, wherein the at least one electrical parameter includes a voltage on one or more of the plurality of differently sized inductive elements.

34. The device of claim 31, wherein the at least one electrical parameter includes a current on one or more of the plurality of differently sized inductive elements.

35. The device of claim 31, wherein one or more of the plurality of differently sized inductive elements that are not connected to the at least one power and control circuit are disabled by open circuiting portions thereof.

36. The device of claim 31, wherein a connection between the plurality of differently sized inductive elements and the at least one power and control circuit is made to maximize a quality factor of the magnetic resonator.

37. The device of claim 31, wherein a connection between the plurality of differently sized inductive elements and the at least one power and control circuit is made to maximize a coupling factor between the magnetic resonator and a second magnetic resonator.