SYSTEM, METHOD AND APPARATUS FOR REDUCING THE HEIGHT OF BIPOLAR TRANSMITTERS AND/OR RECEIVERS IN ELECTRIC VEHICLE CHARGING

• US 20150332845A1
• Filed: 05/14/2014
• Published: 11/19/2015
• Est. Priority Date: 05/14/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Werner, Michael, Widmer, Hanspeter
• Granted Patent: US 10,083,792 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• 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 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• 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: 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 90/14 Plug-in electric vehicles

Abstract

Systems, methods and apparatuses for reducing the height of bipolar transmitters and/or receivers in electric vehicle charging and/or power transfer are described herein. One implementation may include an apparatus for wireless power transfer. The apparatus comprises a ferromagnetic layer comprising at least one portion having a reduced thickness. The apparatus further comprises a first coil having at least one portion countersunk into the at least one portion of the ferromagnetic layer having the reduced thickness. The apparatus further comprises a second coil overlapping the at least one countersunk portion of the first coil. The at least one portion having the reduced thickness comprises a recess in the ferromagnetic layer. The ferromagnetic layer comprises a first plurality of ferromagnetic tiles having a first thickness and the at least one portion having the reduced thickness comprises a second plurality of ferromagnetic tiles having the reduced thickness.

Claims

1. An apparatus for wireless power transfer, comprising:

a ferromagnetic layer comprising at least one portion having a reduced thickness;

a first coil having at least one portion countersunk into the at least one portion of the ferromagnetic layer having the reduced thickness; and

a second coil overlapping the at least one countersunk portion of the first coil.

2. The apparatus of claim 1, wherein the at least one portion having the reduced thickness comprises a recess in the ferromagnetic layer.

3. The apparatus of claim 1, wherein the at least one portion having the reduced thickness comprises a complete removal of the ferromagnetic layer in the at least one portion.

4. The apparatus of claim 1, further comprising a shield layer having at least one portion recessed or removed that is substantially aligned with the at least one portion of the ferromagnetic layer having the reduced thickness.

5. The apparatus of claim 1, wherein the ferromagnetic layer comprises a first plurality of ferromagnetic tiles having a first thickness and the at least one portion having the reduced thickness comprises a second plurality of ferromagnetic tiles having the reduced thickness.

6. The apparatus of claim 1, wherein the ferromagnetic layer, the first coil and the second coil form a bipolar wireless power transmitter or receiver.

7. The apparatus of claim 1, wherein the first and second coils are configured to be driven with respective first and second currents, the first and second currents passing through the respective first and second coils with at least one of a different magnitude or a different phase.

8. The apparatus of claim 1, wherein the first and second coils are configured to generate a magnetic flux for coupling to at least one receive coil.

9. A method for wireless power transfer, comprising:

wirelessly transmitting or receiving power via a first coil having at least one portion countersunk into at least one portion of a ferromagnetic layer having a reduced thickness; and

wirelessly transmitting or receiving power via a second coil overlapping the at least one countersunk portion of the first coil.

10. The method of claim 9, wherein the at least one portion having the reduced thickness comprises a recess in the ferromagnetic layer.

11. The method of claim 9, wherein the at least one portion having the reduced thickness comprises a complete removal of the ferromagnetic layer in the at least one portion.

12. The method of claim 9, further comprising shielding an area from electromagnetic files via a shield layer comprising at least one recessed or removed portion substantially aligned with the at least one portion of the ferromagnetic layer having the reduced thickness.

13. The method of claim 9, wherein the ferromagnetic layer comprises a first plurality of ferromagnetic tiles having a first thickness and the at least one portion having the reduced thickness comprises a second plurality of ferromagnetic tiles having the reduced thickness.

14. The method of claim 9, further comprising driving the first and second coils with respective first and second currents, the first and second currents passing through the respective first and second coils with at least one of a different magnitude or a different phase.

15. The method of claim 9, further comprising utilizing the first and second coils to generate a magnetic flux coupled to at least one receive coil.

16. An apparatus for wireless power transfer, comprising:

a first coil having a first center point; and

a second coil having a second center point and overlapping a portion of the first coil, the first and second coils having a common axis between the first and second center points, wherein the first and second coils each have a first dimension substantially parallel to the common axis that is shorter than a respective second dimension that are each substantially perpendicular to the common axis.

17. The apparatus of claim 16, wherein the common axis comprises a direction of polarization associated with the first and second coils.

18. The apparatus of claim 16, wherein the first and second coils are configured to be driven with respective first and second currents, the first and second currents passing through the respective first and second coils with at least one of a different magnitude or a different phase.

19. The apparatus of claim 16, wherein the first and second coils are configured to generate a magnetic flux for coupling to at least one receive coil.

20. The apparatus of claim 19, wherein a center point of the at least one receive coil is offset from the common axis in a direction perpendicular to the common axis by a distance greater than or equal to a predetermined percentage of the second dimension of the first and second coils.

21. The apparatus of claim 16, further comprising a ferromagnetic layer comprising at least one portion having a reduced thickness.

22. The apparatus of claim 21, wherein the first coil comprises at least one portion countersunk into the at least one portion of the ferromagnetic layer having the reduced thickness.

23. The apparatus of claim 21, wherein the ferromagnetic layer comprises a first plurality of ferromagnetic tiles having a first thickness and the at least one portion having the reduced thickness comprises a second plurality of ferromagnetic tiles having the reduced thickness.

24. A method for wireless power transfer, comprising:

wirelessly transmitting or receiving power via a first coil having a first center point; and

wirelessly transmitting or receiving power via a second coil having a second center point and overlapping a portion of the first coil, the first and second coils having a common axis between the first and second center points, wherein the first and second coils each have a first dimension substantially parallel to the common axis that is shorter than a respective second dimension that are each substantially perpendicular to the common axis.

25. The method of claim 24, wherein the common axis comprises a direction of polarization associated with the first and second coils.

26. The method of claim 24, further comprising driving the first and second coils with respective first and second currents, the first and second currents passing through the respective first and second coils with at least one of a different magnitude or a different phase.

27. The method of claim 24, further comprising generating a magnetic flux for coupling to at least one receive coil by the first and second coils.

28. The method of claim 27, wherein a center point of the at least one receive coil is offset from the common axis in a direction perpendicular to the common axis by a distance greater than or equal to a predetermined percentage of the second dimension of the first and second coils.

29. The method of claim 24, wherein a ferromagnetic layer comprising at least one portion having a reduced thickness is disposed adjacent to the first coil.

30. The method of claim 29, wherein the first coil comprises at least one portion countersunk into the at least one portion having the reduced thickness.