WIRELESS POWER TRANSFER SYSTEM COIL ARRANGEMENTS AND METHOD OF OPERATION

• US 20140070764A1
• Filed: 03/08/2013
• Published: 03/13/2014
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Keeling, Nicholas A.
• Granted Patent: US 9,666,357 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• 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 53/36 by positioning the vehicle
• CPC Class Codes: H01F 2003/005 Magnetic cores for receiving several windings with perpendicular axes, e.g. for antennae or inductive power transfer
• CPC Class Codes: H01F 2005/027 wound on formers for receiving several coils with perpendicular winding axes, e.g. for antennae or inductive power transfer
• CPC Class Codes: H01F 27/38 Auxiliary core members; Auxiliary coils or windings
• 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 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• 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
• 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 30/12 : Remote or cooperative charging

Abstract

This disclosure provides systems, methods and apparatus for wireless power transfer. In one aspect, an apparatus is provided that includes a first conductive structure configured to wirelessly receive power via a magnetic field generated by a transmitter conductive structure having a length greater than a width. The first conductive structure has a length greater than a width and includes co-planar loops enclosing first and second areas. The first conductive structure has first and second edges each intersecting a first geometric line running along the length of the first conductive structure. The apparatus includes a second conductive structure configured to wirelessly receive power via the magnetic field. The second conductive has a length greater than a width. The first geometric line runs along the length of the second conductive structure. The first geometric line is substantially perpendicular to a second geometric line running along the length of the transmitter conductive structure.

Claims

1. An apparatus for wirelessly receiving power, the apparatus comprising

a first conductive structure configured to wirelessly receive power via a magnetic field generated by a transmitter conductive structure having a length greater than a width, the first conductive structure having a length greater than a width, the first conductive structure comprising a first loop and a second loop enclosing a first area and a second area, respectively, the first loop having a first lower surface and the second loop having a second lower surface that are substantially coplanar, the first conductive structure having a first edge and a second edge each intersecting a first geometric line running along the length of the first conductive structure;

and

a second conductive structure configured to wirelessly receive power via the magnetic field, the second conductive structure enclosing a third area and having a length greater than a width, the first geometric line running along the length of the second conductive structure,

the first geometric line being substantially perpendicular to a second geometric line running along the length of the transmitter conductive structure.

2. The apparatus of claim 1, wherein the second conductive structure is positioned such that a center of the third area enclosed by the second conductive structure is positioned substantially over a point between the first loop and the second loop.

3. The apparatus of claim 1, wherein the first conductive structure comprises one of:

a first coil wound to enclose the first area and the second area;

or

a first and a second coil each enclosing the first area and the second area, respectively,

and wherein the second conductive structure comprises a third coil wound to enclose the third area.

4. The apparatus of claim 1, wherein the first conductive structure and the second conductive structure are positioned to maintain a substantial absence of mutual coupling between the first conductive structure and the second conductive structure.

5. The apparatus of claim 4, wherein the substantial absence of mutual coupling occurs at least in part when a net sum of a magnetic field of the first conductive structure that intersects the second conductive structure is substantially zero.

6. The apparatus of claim 1, wherein the first and second conductive structures collectively have a first center point defined by a first geometric rectangle covering a surface area of the first and second conductive structures, wherein the transmitter conductive structure has a second center point defined by a second geometric rectangle covering a surface area of the transmitter conductive structure, and wherein a set of points, defined by offset distances between the first and second center points, in which an amount of coupling is above a threshold is substantially rectangular, the amount of coupling defined at least in part by a value derived from a first coupling coefficient measuring coupling between the first conductive structure and the transmitter conductive structure and a second coupling coefficient measuring coupling between the second conductive structure and the transmitter conductive structure.

7. The apparatus of claim 1, wherein the first and second conductive structures are configured to be affixed to an electric vehicle, the first geometric line being substantially perpendicular to a longitudinal axis of the electric vehicle.

8. The apparatus of claim 1, wherein the first and second conductive structures are tunable and operable at a resonant frequency.

9. The apparatus of claim 1, further comprising a receive circuit coupled to the first and second conductive structures and configured to power or charge an electric vehicle based on at least a portion of a combination of the power received via the first and second conductive structures.

10. The apparatus of claim 1, wherein the first conductive structure has a substantially horizontally polarized magnetic moment, and wherein the second conductive structure has a substantially vertically polarized moment.

11. A method of wirelessly receiving power, the method comprising

wirelessly receiving power, at a first conductive structure, via a magnetic field generated by a transmitter conductive structure having a length greater than a width, the first conductive structure having a length greater than a width, the first conductive structure comprising a first loop and a second loop enclosing a first area and a second area, respectively, the first loop having a first lower surface and the second loop having a second lower surface that are substantially coplanar, the first conductive structure having a first edge and a second edge each intersecting a first geometric line running along the length of the first conductive structure;

and

wirelessly receiving power, at a second conductive structure, via the magnetic field, the second conductive structure enclosing a third area and having a length greater than a width, the first geometric line running along the length of the second conductive structure,

the first geometric line being substantially perpendicular to a second geometric line running along the length of the transmitter conductive structure.

12. The method of claim 11, wherein the second conductive structure is positioned such that a center of the third area enclosed by the second conductive structure is positioned substantially over a point between the first loop and the second loop.

13. The method of claim 11, wherein the first conductive structure comprises one of:

a first coil wound to enclose the first area and the second area;

or

a first and a second coil each enclosing the first area and the second area, respectively,

and wherein the second conductive structure comprises a third coil wound to enclose the third area.

14. The method of claim 11, wherein the first conductive structure and the second conductive structure are positioned to maintain a substantial absence of mutual coupling between the first conductive structure and the second conductive structure.

15. The method of claim 14, wherein the substantial absence of mutual coupling occurs at least in part when a net sum of a magnetic field of the first conductive structure that intersects the second conductive structure is substantially zero.

16. The method of claim 11, wherein the first and second conductive structures collectively have a first center point defined by a first geometric rectangle covering a surface area of the first and second conductive structures, wherein the transmitter conductive structure has a second center point defined by a second geometric rectangle covering a surface area of the transmitter conductive structure, and wherein a set of points, defined by offset distances between the first and second center points, in which an amount of coupling is above a threshold is substantially rectangular, the amount of coupling defined at least in part by a value derived from a first coupling coefficient measuring coupling between the first conductive structure and the transmitter conductive structure and a second coupling coefficient measuring coupling between the second conductive structure and the transmitter conductive structure.

17. The method of claim 11, wherein the first and second conductive structures are configured to be affixed to an electric vehicle, the first geometric line being substantially perpendicular to a longitudinal axis of the electric vehicle.

18. The method of claim 11, wherein the first and second conductive structures are tunable and operable at a resonant frequency.

19. The method of claim 11, further comprising powering or charging an electric vehicle based on at least a portion of a combination of the power received via the first and second conductive structures.

20. The method of claim 11, wherein the first conductive structure has a substantially horizontally polarized magnetic moment, and wherein the second conductive structure has a substantially vertically polarized moment.

21. An apparatus for wirelessly receiving power, the apparatus comprising

a first means for wirelessly receiving power via a magnetic field generated by a means for generating the magnetic field, the generating means having a length greater than a width, the first receiving means having a length greater than a width, the first receiving means comprising a first loop and a second loop enclosing a first area and a second area, respectively, the first loop having a first lower surface and the second loop having a second lower surface that are substantially coplanar, the first receiving means having a first edge and a second edge each intersecting a first geometric line running along the length of the first receiving means;

and

a second means for wirelessly receiving power via the magnetic field, the second receiving means enclosing a third area and having a length greater than a width, the first geometric line running along the length of the second receiving means,

the first geometric line being substantially perpendicular to a second geometric line running along the length of the generating means.

22. The apparatus of claim 21, wherein the second receiving means is positioned such that a center of the third area enclosed by the second receiving means is positioned substantially over a point between the first loop and the second loop.

23. The apparatus of claim 21, wherein the first receiving means comprises one of:

a first coil wound to enclose the first area and the second area;

or

a first and a second coil each enclosing the first area and the second area, respectively,

and wherein the second receiving means comprises a third coil wound to enclose the third area.

24. The apparatus of claim 21, wherein the first receiving means and the second receiving means are positioned to maintain a substantial absence of mutual coupling between the first receiving means and the second receiving means.

25. The apparatus of claim 21, wherein the first and second receiving means collectively have a first center point defined by a first geometric rectangle covering a surface area of the first and second receiving means, wherein the generating means has a second center point defined by a second geometric rectangle covering a surface area of the generating means, and wherein a set of points, defined by offset distances between the first and second center points, in which an amount of coupling is above a threshold is substantially rectangular, the amount of coupling defined at least in part by a value derived from a first coupling coefficient measuring coupling between the first receiving means and the generating means and a second coupling coefficient measuring coupling between the second receiving means and the generating means.

26. The apparatus of claim 21, wherein the first and second receiving means are configured to be affixed to an electric vehicle, the first geometric line being substantially perpendicular to a longitudinal axis of the electric vehicle.

27. The apparatus of claim 21, wherein the first and second receiving means are tunable and operable at a resonant frequency.

28. The apparatus of claim 21, further comprising a receive circuit coupled to the first and second receiving means and configured to power or charge an electric vehicle based on at least a portion of a combination of the power received via the first and second receiving means.

29. The apparatus of claim 21, wherein the first receiving means has a substantially horizontally polarized magnetic moment, and wherein the second receiving means has a substantially vertically polarized moment.

30. A system for wirelessly transferring power, the system comprising:

a power supply configured to output a time-varying signal; and

a transmitter conductive structure configured to receive the time-varying signal and to generate a magnetic field for wirelessly transferring power to a receiver device, the transmitter conductive structure having a length greater than a width,

the receiver device comprising a first conductive structure configured to wirelessly receive power via the magnetic field, the first conductive structure having a length greater than a width, the first conductive structure comprising a first loop and a second loop enclosing a first area and a second area, respectively, the first loop having a first lower surface and the second loop having a second lower surface that are substantially coplanar, the first conductive structure having a first edge and a second edge each intersecting a first geometric line running along the length of the first conductive structure,

the receiver device further comprising a second conductive structure configured to wirelessly receive power via the magnetic field, the second conductive structure enclosing a third area and having a length greater than a width, the first geometric line running along the length of the second conductive structure,

the first geometric line being substantially perpendicular to a second geometric line running along the length of the transmitter conductive structure.

31. The system of claim 30, wherein the first conductive structure and the second conductive structure of the receiver device are positioned to maintain a substantial absence of mutual coupling between the first conductive structure and the second conductive structure.

32. The system of claim 30, wherein the first and second conductive structures collectively have a first center point defined by a first geometric rectangle covering a surface area of the first and second conductive structures, wherein the transmitter conductive structure has a second center point defined by a second geometric rectangle covering a surface area of the transmitter conductive structure, and wherein a set of points, defined by offset distances between the first and second center points, in which an amount of coupling is above a threshold is substantially rectangular, the amount of coupling defined at least in part by a value derived from a first coupling coefficient measuring coupling between the first conductive structure and the transmitter conductive structure and a second coupling coefficient measuring coupling between the second conductive structure and the transmitter conductive structure.