Systems and methods for induction charging with a closed magnetic loop

• US 9,899,878 B2
• Filed: 08/21/2015
• Issued: 02/20/2018
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Davis, Roy Howard
• Primary Examiner(s): Kaplan, Hal
• Application Number:
  US14/832,261
• Publication Number:
  US 20150364929A1
• Time in Patent Office: 914 Days
• Field of Search: 307104, 320108
• CPC Class Codes: H01F 27/42 Circuits specially adapted for the purpose of modifying, or compensating for, electric characteristics of transformers, reactors, or choke coils circuits for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output H02P13/00; impedance networks H03H
• CPC Class Codes: H01F 37/00 Fixed inductances not covered by group H01F17/00
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• 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 7/00302 Overcharge protection

Abstract

In one aspect, an apparatus for wireless power transmission comprises a plurality of coils and a controller. The controller is configured to sequentially energize each coil of the plurality of coils to produce a magnetic field. The controller is configured to select a subset of the plurality of coils based on a measure of coupling between each coil of the subset of the plurality of coils and at least one receiver coil of a chargeable device. The controller is configured to sequentially energize pairs of coils selected from the subset of the plurality of coils. The controller is configured to select at least two coils from the subset of the plurality of coils for wireless power transmission based on a measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device.

Claims

1. An apparatus'"'"' for wireless power transmission, comprising:

a plurality of coils; and

a controller configured to;

sequentially energize each coil of the plurality of coils to produce a magnetic field,

select a subset of the plurality of coils based on a measure of coupling between each coil of the subset of the plurality of coils and at least one receiver coil of a chargeable device,

sequentially energize pairs of coils selected from the subset of the plurality of coils, and

select at least two coils from the subset of the plurality of coils for wireless power transmission based on a measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device.

2. The apparatus of claim 1, wherein:

the measure of coupling between each coil of the subset of the plurality of coils and the at least one receiver coil of the chargeable device is a measure of coupling of power; and

the measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device is a measure of coupling of power.

3. The apparatus of claim 1, wherein the at least two coils from the subset of the plurality of coils and the at least one receiver coil of the chargeable device form a closed magnetic loop.

4. The apparatus of claim 1, wherein a first coil of each of the pairs of coils is energized with an opposite magnetic polarity compared to a second coil of each of the pairs of coils.

5. The apparatus of claim 1, wherein each coil of the plurality of coils is configured to have an opposite magnetic polarity compared to a directly adjacent coil.

6. The apparatus of claim 1, wherein the controller is further configured to cause a polarity of a row of coils or of a column of coils to be the same polarity.

7. The apparatus of claim 1, wherein the controller is further configured to cause a polarity of each coil of the plurality of coils to have an opposite magnetic polarity compared to a directly adjacent coil.

8. A method for wireless power transmission, comprising:

sequentially energizing each coil of a plurality of coils to produce a magnetic field,

selecting a subset of the plurality of coils based on a measure of coupling between each coil of the subset of the plurality of coils and at least one receiver coil of a chargeable device,

sequentially energizing pairs of coils selected from the subset of the plurality of coils, and

selecting at least two coils from the subset of the plurality of coils for wireless power transmission based on a measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device.

9. The method of claim 8, wherein:

the measure of coupling between each coil of the subset of the plurality of coils and the at least one receiver coil of the chargeable device is a measure of coupling of power; and

the measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device is a measure of coupling of power.

10. The method of claim 8, wherein the at least two coils from the subset of the plurality of coils and the at least one receiver coil of the chargeable device form a closed magnetic loop.

11. The method of claim 8, wherein a first coil coil of each of the pairs of coils is energized with an opposite magnetic polarity compared to a second coil of each of the pairs of coils.

12. The method of claim 8, wherein each coil of the plurality of coils is configured to have an opposite magnetic polarity compared to a directly adjacent coil.

13. The method of claim 8, wherein the controller is further configured to cause a polarity of a row of coils or of a column of coils to be the same polarity.

14. The method of claim 8, wherein the controller is further configured to cause a polarity of each coil of the plurality of coils to have an opposite magnetic polarity compared to a directly adjacent coil.

15. An apparatus for wireless power transmission, comprising:

means for sequentially energizing each coil of a plurality of coils to produce a magnetic field,

means for selecting a subset of the plurality of coils based on a measure of coupling between each coil of the subset of the plurality of coils and at least one receiver coil of a chargeable device,

means for sequentially energizing pairs of coils selected from the subset of the plurality of coils, and

means for selecting at least two coils from the subset of the plurality of coils for wireless power transmission based on a measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device.

16. The apparatus of claim 15, wherein:

the measure of coupling between each coil of the subset of the plurality of coils and the at least one receiver coil of the chargeable device is a measure of coupling of power; and

the measure of coupling between each of the pairs of coils and the at least one receiver coil of the chargeable device is a measure of coupling of power.

17. The apparatus of claim 15, wherein the at least two coils from the subset of the plurality of coils and the at least one receiver coil of the chargeable device form a closed magnetic loop.

18. The apparatus of claim 15, wherein a first coil of each of the pairs of coils is energized with an opposite magnetic polarity compared to a second coil of each of the pairs of coils.

19. The apparatus of claim 15, wherein each coil of the plurality of coils is configured to have an opposite magnetic polarity compared to a directly adjacent coil.

20. The apparatus of claim 15, further comprising means for causing a polarity of each coil of the plurality of coils to have an opposite magnetic polarity compared to a directly adjacent coil.