WIRELESS NON-RADIATIVE ENERGY TRANSFER

• US 20100102639A1
• Filed: 09/03/2009
• Published: 04/29/2010
• Est. Priority Date: 07/12/2005
• Status: Abandoned Application

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Karalis, Aristeidis, Soljacic, Marin, Joannopoulos, John D.
• Application Number:
  US12/553,957
• Publication Number:
  US 20100102639A1
• Time in Patent Office: Days
• 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

The electromagnetic energy transfer device includes a first resonator structure receiving energy from an external power supply. The first resonator structure has a first Q-factor. A second resonator structure is positioned distal from the first resonator structure, and supplies useful working power to an external load. The second resonator structure has a second Q-factor. The distance between the two resonators can be larger than the characteristic size of each resonator. Non-radiative energy transfer between the first resonator structure and the second resonator structure is mediated through coupling of their resonant-field evanescent tails.

Claims

1-21. -21. (canceled)

22. A method, comprising:

inducing power into a near field magnetic field of a first high-Q resonator;

operating the first high-Q resonator along with a second high-Q resonator to couple power magnetically to the second high-Q resonator that has at least one characteristic that is matched to a characteristic of the first high-Q resonator; and

tuning at least one of said resonators to improve matching there between.

23. The method of claim 22, further comprising detecting a detuning between the first high-Q resonator and the second high-Q resonator, and carrying out at least one operation responsive to said detecting.

24. A wireless power source, comprising:

a power supply, that produces power to be transmitted wirelessly via a magnetic near-field of a source high-Q resonator; and

an inductive loop resonator part having at least one capacitive part connected to the inductive loop part, wherein the capacitive part is sized such as to adequately store the energy in an electric field of the source high-Q resonator.

25. The source of claim 24, further comprising a device with a device high-Q resonator that is matched to the source high-Q resonator.

26. The source of claim 24, further comprising a tuning part that allows tuning of said source high-Q resonator.

27. The source of claim 25, further comprising a part that detects a detuning between a first high-Q resonator and a second high-Q resonator, and carrying out at least one operation responsive to said detecting, wherein at least one of the first and second high-Q resonators is the source high-Q resonator.

28. A wireless power device, comprising:

a high-Q resonator with an inductive loop part, having at least one capacitive part connected to the inductive loop part, wherein said capacitive part is sized such as to adequately store the energy in an electric field of the high-Q resonator; and

an external load, coupled to receive power from the high-Q resonator that has been transmitted wirelessly via a magnetic near-field.

29. The wireless power device of claim 28, wherein the high-Q resonator forms a device high-Q resonator, and further comprising a source with a source high-Q resonator that is matched to the device high-Q resonator.

30. The wireless power device of claim 28, further comprising a tuning part that allows tuning of at least one of the device and source high-Q resonator.

31. The wireless power device of claim 29, further comprising a part that detects a detuning between the source high-Q resonator and the device high-Q resonator, and carrying out at least one operation responsive to said detecting.

32. A wireless power source, comprising:

a power source connection, that receives energy to be transmitted wirelessly via a magnetic field;

a first conducting loop part electrically connected to receive said energy; and

a second conducting loop part electrically disconnected from said first conducting loop part and from said power source connection, and operating to transfer said energy via a magnetic field.

33. A method, comprising;

transmitting power from a source high-Q resonator to a device high-Q resonator;

automatically detecting a detuning event that detunes a relationship between said source high-Q resonator and device high-Q resonator; and

responsive to said detecting, automatically taking an action to change a characteristic of said transmitting.

34. A wireless power source, comprising:

a power source connection, that receives energy to be transmitted wirelessly via a magnetic field, wherein at least one resonator part is formed of at least a single loop of conductive material; and

a capacitor part, having a value to match an L and C value of the source high-Q resonator to a frequency of the wireless power source.

35. A method comprising:

using a magnetic field to transmit power from a source high-Q resonator to a device high-Q resonator, wherein each of said high-Q resonators has a Q value for a specified frequency, greater than 1000; and

tuning said high-Q resonators to maintain resonance at said specified frequency.

36. A method comprising:

forming a magnetic near-field with energy therein using a source high-Q resonator with a Q value greater than 1000;

extracting energy from the near-field of the source high-Q resonator, at a device high-Q resonator location that is unconnected to said source high-Q resonator by any wires; and

using said energy in an electronic device that is unconnected to said source high-Q resonator by any wires.

37. The method of claim 36, further comprising adaptively tuning at least one of the source and device high-Q resonators.

38. An apparatus comprising:

a device high-Q resonator, operative to extract energy from a magnetic field at a device high-Q resonator location that is unconnected to any source high-Q resonator by any wires; and

a power system, using said energy in an electronic device that is unconnected to said source high-Q resonator by any wires.

39. The apparatus of claim 38, further comprising an adaptive tuning circuit, changing a tuning value of at least one of the source and device high-Q resonators.

40. A method, comprising:

inducing power into a near field magnetic field of a first resonator;

operating the first resonator along with a second resonator to couple power magnetically over a mid-range distance to the second resonator that has at least one characteristic that is matched to a characteristic of the first resonator; and

tuning at least one of said resonators to improve matching there between.

41. The method of claim 40, further comprising detecting a detuning between the first resonator and the second resonator, and carrying out at least one operation responsive to said detecting.

42. A wireless power source, comprising:

a power supply that produces power to be transferred wirelessly over a mid-range distance via a magnetic near-field of a source resonator; and

an inductive loop resonator part having at least one capacitive part connected to the inductive loop part, wherein the capacitive part is sized such as to adequately store the energy in an electric field of the source resonator.

43. The source of claim 42, further comprising a device with a device resonator that is matched to the source resonator.

44. The source of claim 42, further comprising a tuning part that allows tuning of said source resonator.

45. The source of claim 43, further comprising a part that detects a detuning between a first resonator and a second resonator, and carrying out at least one operation responsive to said detecting, wherein at least one of the first and second resonators is the source resonator.

46. A wireless power device, comprising:

a resonator with an inductive loop part, having at least one capacitive part connected to the inductive loop part, wherein said capacitive part is sized such as to adequately store the energy in an electric field of the resonator; and

an external load, coupled to receive power from the resonator that has been transferred wirelessly over a mid-range distance via a magnetic near-field.

47. The wireless power device of claim 46, wherein the resonator forms a device resonator, and further comprising a source with a source resonator that is matched to the device resonator.

48. The wireless power device of claim 46, further comprising a tuning part that allows tuning of at least one of the device and source resonator.

49. The wireless power device of claim 47, further comprising a part that detects a detuning between the source resonator and the device resonator, and carrying out at least one operation responsive to said detecting.

50. A wireless power source, comprising:

a power source connection, that receives energy to be transferred wirelessly over a mid-range distance via a magnetic field;

a first conducting loop part electrically connected to receive said energy; and

a second conducting loop part electrically disconnected from said first conducting loop part and from said power source connection, and operating to transfer said energy via a magnetic field.

51. A method, comprising;

transferring power over a mid-range distance from a source resonator to a device resonator;

automatically detecting a detuning event that detunes a relationship between said source resonator and device resonator; and

responsive to said detecting, automatically taking an action to change a characteristic of said transferring.

52. A wireless power source, comprising:

a power source connection that receives energy to be transmitted wirelessly over a mid-range distance via a magnetic field;

at least one resonator part formed of at least a single loop of conductive material; and

a capacitor part having a value to match an L and C value of the source resonator to a frequency of the wireless power source.

53. A method comprising:

using a magnetic field to transmit power from a source resonator to a device resonator, wherein each of said resonators has a Q value for a specified frequency greater than 1000; and

tuning said resonators to maintain resonance at said specified frequency.

54. A method comprising:

forming a magnetic near-field with energy therein using a source resonator with a Q value greater than 1000;

extracting energy from the near-field of the source resonator at a device resonator location that is unconnected to said source resonator by any wires; and

using said energy in an electronic device that is unconnected to said source resonator by any wires.

55. The method of claim 54, further comprising adaptively tuning at least one of the source and device resonators.

56. An apparatus comprising:

a device resonator operative to extract energy from a magnetic field at a device resonator location that is separated by a mid-range distance and unconnected to any source resonator by any wires; and

a power system using said energy in an electronic device that is unconnected to said source resonator by any wires.

57. The apparatus of claim 56, further comprising an adaptive tuning circuit, changing a tuning value of at least one of the source and device resonators.