WIRELESS CHARGING BASED ON SELECTIVE ACTIVATION OF TRANSMIT ANTENNAS

• US 20160031332A1
• Filed: 08/04/2014
• Published: 02/04/2016
• Est. Priority Date: 08/04/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Garcia Briz, Alberto, Ombach, Grzegorz
• Granted Patent: US 9,505,315 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• 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 53/124 Detection or removal of foreign bodies
• 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: G01V 3/10 using induction coils
• 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 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A wireless power transfer system for selectively disabling a transmit antenna of a plurality of transmit antennas when a foreign object is detected is described. The system comprises a first transmit antenna configured to charge an electric vehicle positioned over a charging region via a first area of the charging region and also comprises a second transmit antenna configured to charge via a second area of the charging region. The system further comprises a controller circuit configured to selectively disable the first transmit antenna when a foreign object is detected in a first space that affects charging via the first area of the charging region. The controller circuit is further configured to selectively maintain activation of the second transmit antenna while the electric vehicle is positioned to receive power from the second transmit antenna via the second area when the foreign object is detected in the first space.

Claims

1. A wireless power transfer system, comprising:

a first transmit antenna configured to charge an electric vehicle positioned over a charging region, the first transmit antenna configured to charge the electric vehicle via a first area of the charging region;

a second transmit antenna configured to charge the electric vehicle positioned over the charging region, the second transmit antenna configured to charge the electric vehicle via a second area of the charging region different than the first area of the charging region;

a controller circuit coupled to the first transmit antenna and the second transmit antenna, the controller circuit configured to selectively;

disable the first transmit antenna when a foreign object is detected in a first space that affects charging via the first area of the charging region; and

maintain activation of the second transmit antenna while the electric vehicle is positioned to receive power from the second transmit antenna via the second area when the foreign object is detected in the first space.

2. The wireless power transfer system of claim 1, further comprising at least one foreign object detector circuit configured to detect the foreign object as being positioned in the first space or in a second space that affects charging via the second area.

3. The wireless power transfer system of claim 1, wherein the controller circuit is further configured to selectively activate the first transmit antenna when the foreign object is not detected in the first space.

4. The wireless power transfer system of claim 1, wherein a plurality of transmit antennas comprises the first transmit antenna and the second transmit antenna, wherein the plurality of transmit antennas is configured to transmit power to a plurality of receive antennas of the electric vehicle, and wherein the controller circuit is coupled to the plurality of transmit antennas and further configured to selectively disable at least one of the plurality of transmit antennas when a total number of the plurality of transmit antennas is greater than a total number of the plurality of receive antennas of the electric vehicle.

5. The wireless power transfer system of claim 4, wherein the plurality of transmit antennas is further configured to transmit less power when the first transmit antenna is disabled relative to when the first transmit antenna is not disabled.

6. The wireless power transfer system of claim 4, wherein the plurality of transmit antennas is further configured to transmit a same amount of power when the first transmit antenna is disabled relative to when the first transmit antenna is not disabled.

7. The wireless power transfer system of claim 4, further comprising a presence detector circuit coupled to the controller circuit,

wherein the first transmit antenna is further configured to transmit power to one or more of the plurality of receive antennas, and the second transmit antenna is further configured to transmit power to one or more of the plurality of receive antennas,

wherein the presence detector circuit is configured to detect when one or more of the plurality of receive antennas is positioned over the first transmit antenna and when one or more of the plurality of receive antennas is positioned over the second transmit antenna, and

wherein the controller circuit is further configured to selectively disable the first transmit antenna when one or more of the plurality of receive antennas is not positioned over the first transmit antenna and to selectively activate the second transmit antenna when one or more of the plurality of receive antennas is positioned over the second transmit antenna.

8. The wireless power transfer system of claim 7, further comprising a communicator circuit coupled to the controller circuit, wherein the communicator circuit is configured to indicate to the electric vehicle that the first transmit antenna is disabled.

9. The wireless power transfer system of claim 7, wherein the controller circuit is further configured to selectively disable the second transmit antenna when one or more of the plurality of receive antennas is not positioned over the second transmit antenna.

10. The wireless power transfer system of claim 1, further comprising a selector circuit coupled to the controller circuit, the first transmit antenna and the second transmit antenna, wherein the selector circuit comprises a switch configured to receive an instruction signal from the controller circuit to selectively disable the first transmit antenna and selectively activate the second transmit antenna.

11. The wireless power transfer system of claim 1, further comprising a transmit circuit comprising the first transmit antenna and the second transmit antenna, wherein the transmit circuit is configured to provide power at a level sufficient to charge or power the electric vehicle.

12. A method of wireless power transfer, comprising:

charging an electric vehicle positioned over a charging region via a first area of the charging region;

charging the electric vehicle positioned over the charging region via a second area of the charging region that is different than the first area;

disabling the charging via the first area when a foreign object is detected in a first space that affects the charging via the first area; and

maintaining the charging via the second area while the electric vehicle is positioned to receive power from the charging via the second area when the foreign object is detected in the first space.

13. The method of claim 12, further comprising:

detecting the foreign object as being in the first space or in a second space that affects charging via the second area.

14. The method of claim 12, further comprising:

selectively activating a first antenna for charging via the first area when the foreign object is not detected in the first space.

15. The method of claim 12, further comprising:

selectively disabling a first transmit antenna of a plurality of transmit antennas when a total number of the plurality of transmit antennas is greater than a total number of a plurality of receive antennas of the electric vehicle.

16. The method of claim 15, further comprising:

indicating to the electric vehicle that the first transmit antenna is disabled; and

selectively disabling a second transmit antenna of the plurality of transmit antennas when a receive antenna of the plurality of receive antennas is not positioned over the second transmit antenna.

17. An apparatus for wirelessly transferring power, comprising:

first means for charging an electric vehicle positioned over a charging region via a first area of the charging region;

second means for charging the electric vehicle via a second area of the charging region different than the first area of the charging region;

means for disabling the first means when a foreign object is detected in a first space that affects charging via the first area; and

means for maintaining activation of the second means while the electric vehicle is positioned to receive power from the second means when the foreign object is detected in the first space.

18. The apparatus of claim 17, further comprising:

means for detecting the foreign object as being in the first space or in a second space that affects charging via the second area.

19. The apparatus of claim 17, further comprising:

means for selectively activating the first means when the foreign object is not detected in the first space.

20. The apparatus of claim 17, wherein the first means for charging comprises a first transmit antenna, the second means for charging comprises a second transmit antenna, the means for disabling comprises a controller circuit, and the means for maintaining activation also comprises the controller circuit.