Contactless power transfer system and method

• US 8,674,550 B2
• Filed: 03/25/2010
• Issued: 03/18/2014
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Bohori, Adnan Kutubuddin, Bray, James William, Ramachandrapanicker, Somakumar, Bhat, Suma Memana Narayana
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): VU, TOAN T
• Application Number:
  US12/731,497
• Publication Number:
  US 20110234010A1
• Time in Patent Office: 1,454 Days
• Field of Search: 307/104, 307/149, 307/157
• US Class Current: 307/104
• 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 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 38/18 Rotary transformers
• 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

Abstract

A contactless power transfer system is proposed. The system includes a first coil coupled to a power source and configured to produce a magnetic field. A second coil is configured to receive power from the first coil via the magnetic field. A field focusing element is disposed between the first coil and the second coil and configured as a self resonant coil having a standing wave current distribution. The field focusing element is further configured to focus the magnetic field onto the second coil and enhance the coupling between the first coil and the second coil.

Claims

1. A contactless power transfer system comprising:

a first coil coupled to a power source and configured to produce a magnetic field;

a second coil configured to receive power from the first coil via the magnetic field; and

a field focusing element disposed between the first coil and the second coil comprising a plurality of resonators arranged in an array, wherein each of the plurality of resonators is configured to be excited by the first coil and upon excitation, the plurality of resonators interfere constructively in a direction of the second coil and interfere destructively in a remaining space to focus the magnetic field onto the second coil and enhance the coupling between the first coil and the second coil.

2. The contactless power transfer system of claim 1, further comprising two or more second coils configured to receive power from the first coil.

3. The contactless power transfer system of claim 1, wherein the second coil is further coupled to a power load.

4. The contactless power transfer system of claim 1, wherein the plurality of resonators comprise two or more resonant frequencies.

5. The contactless power transfer system of claim 4, wherein two or more resonant frequencies are configured to simultaneously transfer power and data signals.

6. The contactless power transfer system of claim 1, wherein the resonators are disposed within at least one of a dielectric medium, a magnetic medium, or a magneto-dielectric medium.

7. The contactless power transfer system of claim 1, wherein the field focusing element is configured for bi-directional power transfer.

8. The contactless power transfer system of claim 1, wherein the magnetic field focusing element comprises at least two sets of resonators.

9. The contactless power transfer system of claim 8, wherein each of the at least two sets of resonators comprises a unique resonant frequency.

10. The contactless power transfer system of claim 8, wherein the magnetic field focusing element is configured to transfer power simultaneous at two or more unique frequencies.

11. The contactless power transfer system of claim 1, wherein at least one of the first coil, the second coil, or the field focusing element is configured to rotate with respect to each other along an axis of rotation.

12. The contactless power transfer system of claim 11, wherein the field focusing element is further configured to focus the magnetic field along the axis of rotation.

13. The contactless power transfer system of claim 1 further comprising at least one capacitive element coupled to each of the first coil and the second coil, wherein the capacitive element is tuned to resonate with the field focusing element.

14. The contactless power transfer system of claim 1, wherein the field focusing element is further configured to focus at least one of an electric field, a magnetic field, or an electromagnetic field.

15. The contactless power transfer system of claim 1, wherein the plurality of resonators comprise at least one of a single turn coil, multiple turn coil, or a helical coil.

16. The contactless power transfer system of claim 1, wherein the plurality of resonators comprise at least one of a spiral structure, a split ring structure, or a Swiss-roll structure.

17. The contactless power transfer system of claim 1, wherein the plurality of resonators form a standing wave current distribution wherein the current distribution within the resonators shapes the magnetic field distribution.

18. The contactless power transfer system of claim 1, wherein the plurality of resonators are configured to shape the magnetic field.

19. The contactless power transfer system of claim 1, wherein the array comprises a linear, a planar, a circular or a three-dimensional structure.