System, method and apparatus for reducing the height of bipolar transmitters and/or receivers in electric vehicle charging

• US 10,083,792 B2
• Filed: 05/14/2014
• Issued: 09/25/2018
• Est. Priority Date: 05/14/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Werner, Michael, Widmer, Hanspeter
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Tran, Thai
• Application Number:
  US14/277,514
• Publication Number:
  US 20150332845A1
• Time in Patent Office: 1,595 Days
• Field of Search: 307104, 320108
• 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 first portion having a first thickness and a plurality of second portions, each having a second thickness less than the first thickness;

a first coil having a first section that rests on the at least one first portion, a plurality of second sections, each of which rests on one of the plurality of second portions of the ferromagnetic layer, and a third section that rests on the at least one first portion, the third section positioned between the plurality of second sections, the plurality of second sections of the first coil not coplanar with the first section, and the first coil configured to be driven with a first current; and

a second coil overlapping the plurality of second sections of the first coil and configured to be driven with a second current different from the first current,

the first and second coils configured to generate a magnetic field that is adjusted based on varying a magnitude or a phase of at least one of the first and second currents.

2. The apparatus of claim 1, wherein each of the plurality of second portions comprises a recess in the ferromagnetic layer.

3. The apparatus of claim 1, wherein each of the plurality of second portions comprises a complete removal of the ferromagnetic layer.

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

5. The apparatus of claim 1, wherein the ferromagnetic layer comprises a first plurality of ferromagnetic tiles having the first thickness and a second plurality of ferromagnetic tiles having the second thickness that is less than the first 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 generate a magnetic flux for coupling to at least one receive coil.

8. The apparatus of claim 1, wherein any section of the first coil which does not rest on one of the plurality of second portions of the ferromagnetic layer is generally coplanar with the second coil.

9. The apparatus of claim 1, wherein the plurality of second sections of the first coil is offset below the first section by a distance equal to a thickness of the first coil.

10. The apparatus of claim 1, wherein the first coil additionally has the third section, the second coil overlapping the third section of the first coil.

11. A method for wireless power transfer, comprising:

wirelessly transmitting or receiving power via a first coil having a first section that rests on a first portion of a ferromagnetic layer having a first thickness, a plurality of second sections, each of which rests on one of a plurality of second portions of the ferromagnetic layer having a second thickness less than the first thickness, and a third section that rests on the first portion, the third section positioned between two of the plurality of second sections, the first coil driven with a first current and the plurality of second sections not coplanar with the first section; and

wirelessly transmitting or receiving power via a second coil overlapping the plurality of second sections of the first coil, the second coil driven with a second current different from the first current,

the first and second coils generating a magnetic field that is adjusted based on varying a magnitude or a phase of at least one of the first and second currents.

12. The method of claim 11, wherein each of the plurality of second portions comprises a recess in the ferromagnetic layer.

13. The method of claim 11, wherein each of the second portions comprises a complete removal of the ferromagnetic layer.

14. The method of claim 11, further comprising shielding an area from electromagnetic fields via a shield layer comprising at least one recessed or removed portion substantially aligned with the plurality of second portions of the ferromagnetic layer.

15. The method of claim 11, wherein the ferromagnetic layer comprises a first plurality of ferromagnetic tiles having the first thickness and a second plurality of ferromagnetic tiles having the second thickness that is less than the first thickness.

16. The method of claim 11, further comprising utilizing the first and second coils to generate a magnetic flux coupled to at least one receive coil.

17. The method of claim 11, wherein the first section of the first coil is generally coplanar with the second coil.

18. The method of claim 11, wherein each of the plurality of second sections of the first coil is offset below the first section of the first coil by a distance equal to a thickness of the first coil.

19. The method of claim 11, wherein the first coil additionally has the third section that rests on the plurality of second portions of the ferromagnetic layer, the second coil overlapping the third section of the first coil.

20. An apparatus for wireless power transfer, comprising:

a ferromagnetic layer comprising at least one first portion having a first thickness and a plurality of second portions, each having a second thickness less than the first thickness, the at least one of the plurality of second portions having a portion in which the ferromagnetic layer is completely removed;

a first coil having at least two first sections that each rests on one of the plurality of second portions, at least one of the first sections extending into a space of the at least one completely removed portion of the ferromagnetic layer, and a second section disposed between at least two of the plurality of first sections that rests on the at least one first portion, the first coil configured to be driven with a first current; and

a second coil overlapping the plurality of first sections of the first coil and configured to be driven with a second current different from the first current,

the first and second coils configured to generate a magnetic field that is adjusted based varying a magnitude or a phase of at least one of the first and second currents.

21. The apparatus of claim 20, further comprising a shield layer having at least one portion recessed or removed that is substantially aligned with the completely removed portion of the ferromagnetic layer.

22. The apparatus of claim 20, wherein the ferromagnetic layer, the first coil and the second coil form a bipolar wireless power transmitter or receiver.

23. The apparatus of claim 20, wherein the first and second coils are configured to generate a magnetic flux for coupling to at least one receive coil.

24. A method for wireless power transfer, comprising:

wirelessly transmitting or receiving power via a first coil having a plurality of first sections, at least one of which extends into an area of at least one completely removed portion of a ferromagnetic layer and a second section disposed between at least two of the plurality of first sections and resting on a first portion of the ferromagnetic layer having a larger thickness than the removed portion, the first coil configured to be driven with a first current; and

wirelessly transmitting or receiving power via a second coil overlapping the at least two of the first sections of the first coil, the second coil configured to be driven with a second current different from the first current,

the first and second coils generating a magnetic field structure that is adjusted based on varying a magnitude and a phase of at least one of the first and second currents.

25. The method of claim 24, further comprising shielding an area from electromagnetic field via a shield layer comprising at least one recessed or removed portion substantially aligned with the at least one completely removed portion of the ferromagnetic layer.

26. The method of claim 24, further comprising utilizing the first and second coils to generate a magnetic flux coupled to at least one receive coil.