WIRELESS NON-RADIATIVE ENERGY TRANSFER

• US 20150188321A1
• Filed: 02/24/2015
• Published: 07/02/2015
• 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
• Granted Patent: US 9,450,421 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 high-Q resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. A third high-Q resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. The source resonator and at least one of the second resonator and third resonator may be coupled to transfer electromagnetic energy from said source resonator to said at least one of the second resonator and third resonator.

Claims

1. A wireless power system for providing power to a vehicle, the system comprising:

a source module comprising a source resonator and a power supply coupled to the source resonator to provide power to the source resonator, the source resonator having a resonant frequency ω

₁, an intrinsic loss rate Γ

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

₁/(2Γ

₁), the source resonator comprising at least one loop of conductive material and further comprising a capacitance; and

a device module housed in the vehicle and comprising a device resonator and a load coupled to the device resonator to receive power from the device resonator and for powering the vehicle, the device resonator having a resonant frequency ω

₂, an intrinsic loss rate Γ

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

₂/(2Γ

₂), the device resonator comprising at least one loop of conductive material and further comprising a capacitance,

wherein the source resonator and the device resonator are configured to resonantly and wirelessly couple electromagnetic power from the source resonator to the device resonator using non-radiative electromagnetic induction having a coupling coefficient κ

, and wherein the intrinsic loss rates satisfy κ

/√

{square root over (Γ

₁Γ

₂>

5 )}over a range of distances D, and

wherein Q₁>

100 and Q₂>

100, and the power to be provided to the load is at least 10 Watts.

2. The wireless power system of claim 1, wherein Q₁>

200 and Q₂>

200.

3. The wireless power system of claim 1, wherein Q₁>

500 and Q₂>

500.

4. The wireless power system of claim 1, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w is configured to be dynamically set as a function of the energy transfer rate κ

between the first and second resonators as the device module is moveable relative to the source module over the range of distances D.

5. The wireless power system of claim 4, wherein the work drainage rate Γ

_w is configured to be dynamically set such that the ratio of useful-to-lost power is maximized as a function of the coupling coefficient κ

over the range of distances D.

6. The wireless power system of claim 4, wherein the work drainage rate Γ

_w is configured to be dynamically set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} as a function of the coupling coefficient κ

over the range of distances D.

7. The wireless power system of claim 1, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w is configured to be set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} for some value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.

8. The wireless power system of claim 1, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w is configured to be set such that the ratio of useful-to-lost power is maximized for some value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.

9. The wireless power system of claim 8, wherein the work drainage rate Γ

_w is configured to be set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} for said value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.

10. The wireless power system of claim 1, wherein the range of distances D includes D=6 cm.

11. The wireless power system of claim 1, wherein the range of distances D includes D=8 cm.

12. The wireless power system of claim 1, wherein the range of distances D includes D=10 cm.

13. The wireless power system of claim 4, wherein the range of distances D includes D=6 cm.

14. The wireless power system of claim 4, wherein the range of distances D includes D=8 cm.

15. The wireless power system of claim 4, wherein the range of distances D includes D=10 cm.

16. The wireless power system of claim 8, wherein the range of distances D includes D=6 cm.

17. The wireless power system of claim 8, wherein the range of distances D includes D=8 cm.

18. The wireless power system of claim 8, wherein the range of distances D includes D=10 cm.

19. The wireless power system of claim 1, wherein the non-radiative electromagnetic induction means that the distances D are less than the wavelengths corresponding to the resonant frequencies ω

₁ and ω

₂.

20. The wireless power system of claim 1, further comprising a feedback mechanism coupled to at least one of the resonators to correct for detuning of the resonant frequencies.

21. A source module for a wireless power system for providing power to a vehicle, the wireless power system including a device module housed in the vehicle and comprising a device resonator and a load coupled to the device resonator to receive power from the device resonator and for powering the vehicle, the device resonator having a resonant frequency ω

₂, an intrinsic loss rate Γ

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

₂/(2Γ

₂), the device resonator comprising at least one loop of conductive material and further comprising a capacitance,

the source module comprising;

a source resonator and a power supply coupled to the source resonator to provide power to the source resonator, the source resonator having a resonant frequency ω

₁, an intrinsic loss rate ω

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

₁/(2Γ

₁)>

100, the source resonator comprising at least one loop of conductive material and further comprising a capacitance,

wherein the source resonator and the device resonator are configured to resonantly and wirelessly couple electromagnetic power from the source resonator to the device resonator using non-radiative electromagnetic induction having a coupling coefficient κ

, and wherein the intrinsic loss rates satisfy κ

/√

{square root over (Γ

₁Γ

₂)}>

5 over a range of distances D, and

wherein Q₁>

100 and Q₂>

100, and the power to be provided to the load is at least 10 Watts.

22. A device module for use in a wireless power system for providing for providing power to a vehicle, the wireless power system including a source module having a source resonator and a power supply coupled to the source resonator to provide power to the source resonator, the source resonator having a resonant frequency ω

₁, an intrinsic loss rate Γ

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

₁/(2Γ

₁),

the device module comprising;

a device module housed in the vehicle and comprising a device resonator and a load coupled to the device resonator to receive power from the device resonator and for powering the vehicle, the device resonator having a resonant frequency ω

₂, an intrinsic loss rate Γ

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

₂/(2Γ

₂), the device resonator comprising at least one loop of conductive material and further comprising a capacitance,

wherein the source resonator and the device resonator are configured to resonantly and wirelessly couple electromagnetic power from the source resonator to the device resonator using non-radiative electromagnetic induction having a coupling coefficient κ

, and wherein the intrinsic loss rates satisfy κ

/√

{square root over (Γ

₁Γ

₂)}>

5 over a range of distances D, and

wherein Q₁>

100 and Q₂>

100, and the power to be provided to the load is at least 10 Watts.

23. The device module of claim 22, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w, is configured to be dynamically set as a function of the coupling coefficient κ

between the first and second resonators as the device module is movable relative to the source module over the range of distances D.

24. The device module of claim 23, wherein the work drainage rate Γ

_w is configured to be dynamically set such that the ratio of useful-to-lost power is maximized as a function of the coupling coefficient κ

over the range of distances D.

25. The device module of claim 23, wherein the work drainage rate Γ

_w is configured to be dynamically set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} as a function of the coupling coefficient κ

over the range of distances D.

26. The device module of claim 22, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_wis configured to be set such that the ratio of useful-to-lost power is maximized for some value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.

27. The device module of claim 24, wherein the work drainage rate Γ

_w is configured to be set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} for said value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.

28. A method for providing power wirelessly to a vehicle portable electronic device, wherein the vehicle is configured for use with a source module having a source resonator and a power supply coupled to the source resonator to provide power to the source resonator, the source resonator having a resonant frequency ω

₁, an intrinsic loss rate Γ

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

₁/(2Γ

₁), the method comprising;

providing the vehicle with a device resonator and a load coupled to the device resonator to receive power from the device resonator and provide power to the vehicle, the device resonator having a resonant frequency ω

₂, an intrinsic loss rate Γ

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

₂/(2Γ

₂), the device resonator comprising at least one loop of conductive material and further comprising a capacitance, wherein the device module is spaced from the source module and configured to move freely relative to the source module over a range of distances D between the source module and the device module; and

resonantly and wirelessly receiving electromagnetic power at the device resonator from the source resonator using non-radiative electromagnetic induction having a coupling coefficient κ

wherein the intrinsic loss rates satisfy κ

/√

{square root over (Γ

₁Γ

₂)}>

5 over the range of distances D, and wherein each intrinsic loss rate comprises a resistive component and a radiative component,

wherein Q₁>

100 and Q₂>

100, and the power to be provided to the load is at least 10 Watts.

29. The method of claim 28, further comprising:

providing power to the load in the vehicle from the device resonator, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w is dynamically set as a function of the coupling coefficient κ

between the first and second resonators as the device module moves relative to the source module over the range of distances D.

30. The method of claim 29, wherein the work drainage rate Γ

_w is dynamically set such that the ratio of useful-to-lost power is maximized as a function of the coupling coefficient κ

over the range of distances D.

31. The method of claim 29, wherein the work drainage rate Γ

_w is dynamically set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} as a function of the coupling coefficient κ

over the range of distances D.

32. The method of claim 28, further comprising:

providing power to the load in the vehicle from the device resonator, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w is set such that Γ

_w=Γ

₂√

{square root over (1+(κ

²/Γ

₁·

Γ

₂))} for some value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.

33. The method of claim 28, further comprising:

providing power to the load in the vehicle from the device resonator, wherein the power provided to the load from the device resonator defines a work drainage rate Γ

_w, and wherein the work drainage rate Γ

_w is set such that the ratio of useful-to-lost power is maximized for some value of the coupling coefficient κ

in the range of distances D as the device module is moveable relative to the source module over the range of distances D.