WIRELESS ENERGY TRANSFER SYSTEMS

• US 20100109445A1
• Filed: 11/06/2009
• Published: 05/06/2010
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Kesler, Morris P., Karalis, Aristeidis, Hall, Katherine L., Soljacic, Marin, Kurs, Andre B.
• Granted Patent: US 8,035,255 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2200/22 Microcars, e.g. golf cars
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 2260/32 Auto pilot mode
• CPC Class Codes: B60L 50/20 using propulsion power generated by humans or animals
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• 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: B60L 53/51 Photovoltaic means
• CPC Class Codes: B60L 53/63 in response to network capacity
• CPC Class Codes: B60L 53/64 Optimising energy costs, e.g. responding to electricity rates
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• CPC Class Codes: B60L 55/00 : Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: H01F 38/14 : Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 2310/40 : The network being an on-board power network, i.e. within a vehicle
• 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
• 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 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/35 : with light sensitive cells
• CPC Class Codes: H03H 7/40 : Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 5/266 : One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/79 : for data transfer in combination with power transfer
• CPC Class Codes: Y02E 60/00 : Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• 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 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

Described herein are improved capabilities for a source resonator having a Q-factor Q₁>100 and a characteristic size x₁ coupled to an energy source, and a second resonator having a Q-factor Q₂>100 and a characteristic size x₂ coupled to an energy drain located a distance D from the source resonator, where the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator.

Claims

1. A wireless power transfer system comprising:

a source unit with at least one source planar magnetic resonator coupled to a power generator, and arranged such that the dipole moment of the said source planar magnetic resonator is oriented substantially in a plane of the source planar magnetic resonator;

at least one device unit with at least one device planar magnetic resonator arranged such that the dipole moment of the said device planar magnetic resonator is oriented substantially in a plane of the device planar magnetic resonator; and

an active area around the source unit such that when the said device unit is placed in the active area alternating magnetic fields generated by at least one of the source planar magnetic resonators induce a current in at least one of the said device planar magnetic resonators of the said device unit,

wherein the said active area of the power transfer system is at least two times the area enclosed by the perimeter of the said source planar magnetic resonator.

2. The system of claim 1, wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 1%.

3. The system of claim 1, wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 10%.

4. The system of claim 1, wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 50%.

5. The system of claim 1, wherein the active area is the area in which the induced current in at least one device planar magnetic resonator of the device unit is sufficient to deliver at least 10 mW of power to the device unit.

6. The system of claim 1, wherein the active area is the area in which the induced current in at least one device planar magnetic resonator of the device unit is sufficient to deliver at least 5 W of power to the device unit.

7. The system of claim 1, wherein the active area is the area in which the induced current in at least one device planar magnetic resonator of the device unit is sufficient to deliver at least 1 kW of power to the device unit.

8. The system of claim 1, wherein the active area is at least five times the area enclosed by the perimeter of the said source planar magnetic resonator.

9. The system of claim 1, wherein at least one source planar magnetic resonator comprises at least one electrical conductor wrapped around a core of magnetic material.

10. The system of claim 1, wherein at least one device planar magnetic resonator comprises at least one electrical conductor wrapped around a core of magnetic material.

11. The system of claim 1, wherein at least one planar magnetic resonator of the said system comprises at least one electrical conductor wrapped around a core of magnetic material.

12. The system of claim 11, further comprising at least one electrical component network, wherein the said electrical component network is coupled to at least one electrical conductor.

13. The system of claim 12, wherein at least one electrical component network comprises at least one capacitor.

14. The system of claim 12, wherein at least one electrical component network comprises at least one inductor.

15. The system of claim 12, wherein at least one electrical component network comprises at least one variable component.

16. The system of claim 12, wherein at least one electrical component network comprises at least one tunable component.

17. The system of claim 12, wherein the electrical component network is connected to the at least one electrical conductor using a direct physical connection.

18. The system of claim 12, wherein the electrical component network is connected to the at least one electrical conductor using an inductive connection.

19. The system of claim 11, wherein the electrical conductor is wrapped around the core of magnetic material forming loops of which some are not coaxial.

20. The system of claim 11, wherein at least one planar magnetic resonator has a quality factor Q>

100.

21. The system of claim 11, wherein all the planar magnetic resonators of the system have a quality factor greater than 100.

22. The system of claim 11, wherein the core comprises ferrite materials.

23. The system of claim 11, wherein the core contains shielded enclosures.

24. The system of claim 11, wherein the core contains shielded enclosures at least partially encased in magnetic materials.

25. The system of claim 11, wherein the smallest dimension of the core is at most 30% of the largest dimension.

26. The system of claim 11, wherein the electrical conductor comprises litz wire.

27. The system of claim 11, wherein the electrical conductor comprises a flex circuit.

28. The system of claim 11, wherein the electrical conductor comprises printed conductor traces.

29. The system of claim 11, wherein the electrical conductor is wrapped around the said core to generate said active area that is substantially uniform around the resonator.

30. The system of claim 11, wherein the electrical conductor is wrapped around the said core to generate said active area that is substantially non uniform around the resonator.

31. The system of claim 11, further comprising a capacitively loaded conductor loop resonator in the source unit wherein the capacitively loaded conductor loop is coupled to a power generator and is shaped as to form loops that are in the plane of at least one of the source planar magnetic resonators.

32. The system of claim 31, further comprising a capacitively loaded conductor loop resonator in the device unit wherein the capacitively loaded conductor is shaped as to form loops that are in the plane of at least one of the device planar magnetic resonators.

33. The system of claim 11, further comprising a capacitively loaded conductor loop resonator shaped as to form loops that are in the plane of the source planar magnetic resonator.

34. The system of claim 11, wherein the core is shaped to generate said active area that is substantially uniform around the source planar magnetic resonator.

35. The system of claim 11, wherein the core is shaped to generate said active area that is substantially non uniform around the source unit.

36. The system of claim 1, wherein at least one source planar magnetic resonator comprises two conductors wrapped around orthogonal axes of a core of magnetic material.

37. The system of claim 1, wherein at least one device planar magnetic resonator comprises two conductors wrapped around orthogonal axes of a core of magnetic material.

38. The system of claim 11, wherein the source unit is integrated with an electronic device.

39. The system of claim 11, wherein the source unit is designed to be placed on a flat surface.

40. The system of claim 11, wherein the source unit is designed to be hung from a wall or a mount.

41. A wireless power transfer method comprising the steps of:

providing a source unit with at least one source planar magnetic resonator coupled to a power generator and arranged such that the dipole moment of the said planar source magnetic resonator is oriented substantially in a plane of the source planar magnetic resonator,

providing at least one device unit with at least one device planar magnetic resonator and arranged such that the dipole moment of the said device planar magnetic resonator is oriented substantially in the plane of the device planar magnetic resonator, and

providing power to at least one of the said source planar magnetic resonators through the power generator to generate an active area of alternating electromagnetic field around the source unit,

wherein the said active area is at least two times the area enclosed by the perimeter of the said source planar magnetic resonator.

42. The method of claim 41, wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 1%.

43. The method of claim 41, wherein the active area is at least five times the area enclosed by the perimeter of the said source planar magnetic resonator.

44. The method of claim 41, wherein at least one planar magnetic resonator of the said method comprises at least one electrical conductor wrapped around a core of magnetic material.

45. The method of claim 41, wherein at least one planar magnetic resonator has a quality factor greater than 100.

46. The method of claim 41, wherein all the planar magnetic resonators of the method have a quality factor greater than 100.