Wireless energy transfer with high-Q from more than one source

• US 8,400,019 B2
• Filed: 12/16/2009
• Issued: 03/19/2013
• Est. Priority Date: 07/12/2005
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Joannopoulos, John D., Karalis, Aristeidis, Soljacic, Marin
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US12/639,966
• Publication Number:
  US 20100123353A1
• Time in Patent Office: 1,189 Days
• Field of Search: 307/104, 333/195
• US Class Current: 307/104
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• 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 9/04 Resonant antennas
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02M 1/0064 Magnetic structures combining different functions, e.g. storage, filtering or transformation
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H04B 5/0037 for power transfer
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

Described herein are embodiments of a source high-Q resonator, optionally coupled to an energy source, a second source high-Q resonator, optionally coupled to an energy source, and a third high-Q resonator, optionally coupled to an energy drain, where at least one of the source resonators and the third resonator may be coupled to transfer electromagnetic energy from at least one of the said source resonators to said third resonator.

Claims

1. A system, comprising:

a source high-Q resonator, configured to be coupled to an energy source, the source high-Q resonator having a resonant frequency ω

₁ and an intrinsic loss rate Γ

₁, and capable of storing electromagnetic energy with a high intrinsic quality factor Q₁=ω

₁/(2Γ

₁);

a second source high-Q resonator, configured to be coupled to an energy source, the second source high-Q resonator having a resonant frequency ω

₂ and an intrinsic loss rate Γ

₂, and capable of storing electromagnetic energy with a high intrinsic quality factor Q₂=ω

₂/(2Γ

₂); and

a third high-Q resonator, the third high-Q resonator having a resonant frequency ω

₃ and an intrinsic loss rate Γ

₃, and capable of storing electromagnetic energy with a high intrinsic quality factor Q₃=ω

₃/(2Γ

₃),

wherein at least one of the source resonators and the third resonator are configured to be coupled to transfer electromagnetic energy from at least one of the said source resonators to said third resonator via wireless near-field energy transfer.

2. The system of claim 1, further comprising the first mentioned energy source coupled to the first-mentioned source resonator and the second-mentioned energy source coupled to the second source resonator.

3. The system of claim 1, further comprising an energy drain coupled to the third resonator.

4. The system of claim 3, wherein the energy drain comprises a robot, vehicle, computer, cell phone, or a portable electronic device.

5. The system of claim 1, wherein at least one of Q₁, Q₂, and Q₃ is greater than 100.

6. The system of claim 5, wherein another of Q₁, Q₂, and Q₃ is greater than 100.

7. The system of claim 1, wherein third resonator is electromagnetically coupled to at least one of the source resonators.

8. The system of claim 7, wherein the source resonators are each configured to wirelessly transfer electromagnetic energy to the third resonator.

9. The system of claim 7, wherein at least one of Q₁, Q₂, and Q₃ is greater than 100.

10. The system of claim 9, wherein another of Q₁, Q₂, and Q₃ is greater than 100.

11. The system of claim 1, wherein at least one of the resonators is tunable.

12. The system of claim 1, wherein the third resonator is movable relative to the source resonators and wherein the wireless energy transfer occurs over a range of distances.

13. The system of claim 12, wherein the range of distances includes 5 cm.

14. The system of claim 12, wherein the range of distances includes 10 cm.

15. The system of claim 12, wherein the range of distances includes 30 cm.

16. The system of claim 12, wherein κ

/√

{square root over (Γ

₁Γ

₂)}>

0.2 over the range of distances, wherein κ

is the wireless energy transfer rate, Γ

₁ is the intrinsic loss rate of said at least one of the source resonators, and Γ

₂ is the intrinsic loss rate of the third resonator.

17. The system of claim 16, wherein κ

/√

{square root over (Γ

₁Γ

₂)}>

0.5 over the range of distances.

18. The system of claim 16, wherein κ

/√

{square root over (Γ

₁Γ

₂)}>

1 over the range of distances.

19. The system of claim 12, wherein the efficiency of the wireless energy transfer is at least 20% over the range of distances.

20. The system of claim 1, wherein the resonant frequencies f₁=ω

₁/2π

, f₂=ω

₂/2π

, and f₃=ω

₃/2π

of the resonators are each at least 5 MHz.

21. The system of claim 1, further comprising a feedback mechanism coupled to at least one of the resonators to correct for detuning.

22. The system of claim 1, wherein the first-mentioned energy source is coupled to the first-mentioned source resonator, an energy drain is coupled to the third resonator, and the first-mentioned source resonator is electromagnetically coupled to the third resonator, and wherein the first-mentioned energy source and energy drain are configured to be driven to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ

between the first-mentioned source resonator and the third resonator.

23. The system of claim 1, wherein the first-mentioned source resonator is electromagnetically coupled to the third resonator, and wherein the first-mentioned source resonator and third resonator are configured to be adjustably tuned to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ

between the first-mentioned source resonator and the third resonator.

24. The system of claim 1, wherein the source resonator and the third resonator have different characteristic sizes.

25. A method, comprising:

providing a source high-Q resonator, configured to be coupled to an energy source, the source high-Q resonator having a resonant frequency ω

₁ and an intrinsic loss rate Γ

₁, and capable of storing electromagnetic energy with a high intrinsic quality factor Q₁=ω

₁/(2Γ

₁);

providing a second source high-Q resonator, configured to be coupled to an energy source, the second source high-Q resonator having a resonant frequency ω

₂ and an intrinsic loss rate Γ

₂, and capable of storing electromagnetic energy with a high intrinsic quality factor Q₂=ω

₂/(2Γ

₂); and

providing a third high-Q resonator, the third high-Q resonator having a resonant frequency ω

₃ and an intrinsic loss rate Γ

₃, and capable of storing electromagnetic energy with a high intrinsic quality factor Q₃=ω

₃/(2Γ

₃),

wherein at least one of the source resonators and the third resonator are configured to be coupled to transfer electromagnetic energy from at least one of the said source resonators to said third resonator via wireless near-field energy transfer.

26. The method of claim 25, wherein the first-mentioned energy source is coupled to the first-mentioned source resonator.

27. The method of claim 25, wherein an energy drain is coupled to the third resonator.

28. The method of claim 27, wherein the energy drain comprises a robot, vehicle, computer, cell phone, or a portable electronic device.

29. The method of claim 25, wherein at least one of Q₁, Q₂, and Q₃ is greater than 100.

30. The method of claim 29, wherein another of Q₁, Q₂, and Q₃ is greater than 100.

31. The method of claim 25, wherein the third resonator is electromagnetically coupled to at least one of the source resonators.

32. The method of claim 31, wherein each of the source resonators is configured to wirelessly transfer electromagnetic energy to the third resonator.

33. The method of claim 31, wherein at least one of Q₁, Q₂, and Q₃ is greater than 100.

34. The method of claim 31, wherein another of Q₁, Q₂, and Q₃ is greater than 100.

35. The method of claim 25, wherein at least one of the resonators is tunable.

36. The method of claim 25, wherein the third resonator is movable relative to each of the source resonators and wherein the wireless energy transfer occurs over a range of distances.

37. The method of claim 36, wherein the range of distances includes 5 cm.

38. The method of claim 36, wherein the range of distances includes 10 cm.

39. The method of claim 36, wherein the range of distances includes 30 cm.

40. The method of claim 36, wherein κ

/√

{square root over (Γ

₁Γ

₂)}>

0.2 over the range of distances, wherein κ

is the wireless energy transfer rate, Γ

₁ is the intrinsic loss rate of said at least one of the source resonators, and Γ

₂ is the intrinsic loss rate of the third resonator.

41. The method of claim 40, wherein κ

/√

{square root over (Γ

₁Γ

₂)}>

0.5 over the range of distances.

42. The method of claim 40, wherein κ

/√

{square root over (Γ

₁Γ

₂)}>

1 over the range of distances.

43. The method of claim 36, wherein the efficiency of the wireless energy transfer is at least 20% over the range of distances.

44. The method of claim 25, wherein the resonant frequencies f₁=ω

₁/2π

, f₂=ω

₂/2π

, and f₃=ω

₃/2π

of the resonators are each at least 5 MHz.

45. The method of claim 25, wherein a feedback mechanism is coupled to at least one of the resonators to correct for detuning.

46. The method of claim 25, wherein the energy source is coupled to the first-mentioned source resonator, an energy drain is coupled to the third resonator, and the first-mentioned source resonator is electromagnetically coupled to the third resonator, and wherein the first-mentioned energy source and energy drain is driven to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ

between the first-mentioned source resonator and the third resonator.

47. The method of claim 25, wherein the first-mentioned source resonator is electromagnetically coupled to the third resonator, and wherein the first-mentioned source resonator and third resonator are adjustably tuned to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ

between the first-mentioned source resonator and the third resonator.

48. The method of claim 25, wherein the source resonator and the third resonator have different characteristic sizes.