WIRELESS ENERGY TRANSFER IN LOSSY ENVIRONMENTS

• US 20100219694A1
• Filed: 02/13/2010
• Published: 09/02/2010
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Kesler, Morris P., Hall, Katherine L., Soljacic, Marin, Kurs, Andre B., Giler, Eric R.
• Granted Patent: US 9,184,595 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 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• 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 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance

Abstract

Described herein are improved configurations for a wireless power transfer for electronic devices that include at least one source magnetic resonator including a capacitively-loaded conducting loop coupled to a power source and configured to generate an oscillating magnetic field and at least one device magnetic resonator, distal from said source resonators, comprising a capacitively-loaded conducting loop configured to convert said oscillating magnetic fields into electrical energy, wherein at least one said resonator has a keep-out zone around the resonator that surrounds the resonator with a layer of non-lossy material.

Claims

1. A wireless power transfer system comprising:

at least one source magnetic resonator comprising a capacitively-loaded conducting loop coupled to a power source and configured to generate an oscillating magnetic field; and

at least one device magnetic resonator, distal from said source resonators, comprising a capacitively-loaded conducting loop configured to convert said oscillating magnetic fields into electrical energy;

wherein at least one said resonator has a keep-out zone around the resonator that surrounds the resonator with a layer of non-lossy material.

2. The system of claim 1, wherein the keep-out zone extends at a symmetric distance around the resonator.

3. The system of claim 1, wherein the keep-out zone extends at a asymmetric distance around the resonator.

4. The system of claim 3, wherein the keep-out zone is largest around regions of the resonator where the electric fields are the largest.

5. The system of claim 1, wherein the smallest keep-out zone exceeds 0.25 mm.

6. The system of claim 1, wherein the smallest keep-out zone exceeds 1 cm.

7. The system of claim 1, wherein the smallest keep-out zone exceeds 10 cm.

8. The system of claim 1, wherein the smallest keep-out zone is approximately 1.0% of the characteristic size of the resonator.

9. The system of claim 1, wherein the smallest keep-out zone is approximately 0.1% of the characteristic size of the resonator.

10. The system of claim 1, wherein the magnetic resonator further comprises a magnetic material.

11. The system of claim 1, wherein at least one magnetic resonator has an intrinsic Q greater than 100.

12. The system of claim 10, wherein at least one magnetic resonator is immersed in water.

13. The system of claim 10, wherein at least one magnetic resonator is immersed in oil.

14. The system of claim 10, wherein at least one magnetic resonator is immersed in earthen materials.

15. The system of claim 10, wherein at least one magnetic resonator is located in a well.

16. The system of claim 10, wherein at least one magnetic resonator is located inside a living creature.

17. A method for wireless power transfer comprising:

energizing at least one source magnetic resonator comprising a capacitively-loaded conducting loop to generate an oscillating magnetic field; and

providing at least one device magnetic resonator, distal from said source resonators, comprising a capacitively-loaded conducting loop configured to convert said oscillating magnetic fields into electrical energy;

maintaining a keep-out zone around at least one resonator to maintain a separation distance between the resonator and lossy material of the environment.

18. The method of claim 17, wherein the keep-out zone extends at a symmetric distance around the resonator.

19. The method of claim 17, wherein the keep-out zone extends at an asymmetric distance around the resonator.

20. The method of claim 17, wherein the smallest keep out zone exceeds 0.25 mm.

21. The method of claim 17, wherein the smallest keep out zone exceeds 1 cm.

22. The method of claim 17, wherein the smallest keep out zone exceeds 10 cm.

23. The method of claim 17, wherein the smallest keep out zone is approximately 1.0% of the characteristic size of the resonator.

24. The method of claim 17, wherein the smallest keep out zone is approximately 0.1% of the characteristic size of the resonator.

25. The method of claim 17, wherein the magnetic resonator further comprises a magnetic material.

26. The method of claim 17, wherein at least one magnetic resonator has an intrinsic Q greater than 100.

27. The method of claim 26, wherein at least one magnetic resonator is immersed in water.

28. The method of claim 26, wherein at least one magnetic resonator is immersed in oil.

29. The method of claim 26, wherein at least one magnetic resonator is immersed in earthen materials.

30. The method of claim 26, wherein at least one magnetic resonator is located in a well.

31. The method of claim 26, wherein at least one magnetic resonator is located inside a living creature.

32. A source for wireless power transfer in a shaft comprising

a capacitively-loaded conducting loop wrapped around a core of magnetic material and coupled to a power source and configured to generate an oscillating magnetic field;

wherein the conducting loops are oriented to be coaxial with length of the shaft.

33. The source of claim 32, further comprising a plurality of capacitively-loaded conducting loops wrapped around cores of magnetic material arranged around the diameter of the shaft.