Systems and methods for bi-state impedance conversion in wireless power transfer

• US 9,302,591 B2
• Filed: 09/13/2013
• Issued: 04/05/2016
• Est. Priority Date: 09/13/2013
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Huang, Chang-Yu, Beaver, Jonathan, Keeling, Nicholas Athol, Budhia, Mickel Bipin, Kissin, Michael Le Gallais
• Primary Examiner(s): Tat, Binh
• Application Number:
  US14/027,097
• Publication Number:
  US 20150077046A1
• Time in Patent Office: 935 Days
• Field of Search: 320106-115
• US Class Current: 1/1
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• 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: B60L 53/30 Constructional details of charging stations
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: B60L 53/62 in response to charging parameters, e.g. current, voltage or electrical charge
• CPC Class Codes: B60L 53/68 Off-site monitoring or control, e.g. remote control
• 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 50/80 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: 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
• 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

One aspect provides a wireless power transmitter. The wireless power transmitter includes a transmit antenna configured to generate a field for wireless transmit power in both a first and second configuration. The wireless power transmitter further includes a first capacitor. The wireless power transmitter further includes at least one switch configured to selectively connect the first capacitor in one of the first and second configuration. The first capacitor can be in series with the transmit antenna in the first configuration and in parallel with the transmit antenna in the second configuration.

Claims

1. A wireless power transmitter comprising:

a transmit antenna configured to generate a field for wireless transmit power in both a first and second configuration;

a first capacitor;

at least one switch configured to selectively connect the first capacitor in one of the first and second configuration, the first capacitor being in series with the transmit antenna in the first configuration and in parallel with the transmit antenna in the second configuration; and

a second capacitor in parallel with the transmit antenna, wherein the first capacitor is in parallel with the second capacitor in the first configuration and in series with the second capacitor in the second configuration.

2. The wireless power transmitter of claim 1, further comprising a third capacitor in series with the at least one switch.

3. The wireless power transmitter of claim 2, wherein the third capacitor is configured to compensate for an additional reactive loading present in the first configuration.

4. The wireless power transmitter of claim 1, wherein the at least one switch is not part of a resonant path.

5. The wireless power transmitter of claim 1, wherein the at least one switch is configured to selectively connect the first capacitor in one of the first and second configuration based on a coupling between the transmit antenna and a receiver.

6. The wireless power transmitter of claim 4, further comprising at least one processor configured to measure the coupling between the transmit antenna and the receiver, and to compare the coupling to a threshold.

7. The wireless power transmitter of claim 1, further comprising a multi-tap transformer configured to operate at a first turns-ratio in the first configuration and a second turns-ratio in the second configuration, the first turns-ratio being higher than the second turns-ratio.

8. A method comprising of transmitting wireless charging power in a wireless power transmitter, comprising:

generating, at a transmit antenna, a field for wireless transmit power in both a first and second configuration;

selectively connecting a first capacitor in one of the first and second configuration, the first capacitor being in series with the transmit antenna in the first configuration and in parallel with the transmit antenna in the second configuration; and

connecting the first capacitor in parallel with a second capacitor in the first configuration and in series with the second capacitor in the second configuration, the second capacitor in parallel with the transmit antenna.

9. The method of claim 8, wherein the wireless power transmitter comprises a third capacitor in series with at least one switch.

10. The method of claim 9, wherein the third capacitor is configured to compensate for an additional reactive loading present in the first configuration.

11. The method of claim 8, wherein said connecting is via at least one switch is not part of a resonant path.

12. The method of claim 8, further comprising selectively connecting the first capacitor in one of the first and second configuration based on a coupling between the transmit antenna and a receiver.

13. The method of claim 12, further comprising measuring the coupling between the transmit antenna and the receiver, and comparing the coupling to a threshold.

14. The method of claim 8, further comprising configuring a multi-tap transformer to operate at a first turns-ratio in the first configuration and a second turns-ratio in the second configuration, the first turns-ratio being higher than the second turns-ratio.

15. An apparatus for transmitting wireless charging power, comprising:

a first capacitor;

means for generating a field for wireless transmit power in both a first and second configuration;

a second capacitor in parallel with the means for generating the field;

means for selectively connecting the first capacitor in one of the first and second configuration, the first capacitor being in series with the means for generating in the first configuration and in parallel with the means for generating in the second configuration; and

means for connecting the first capacitor in parallel with the second capacitor in the first configuration and in series with the second capacitor in the second configuration.

16. The apparatus of claim 15, further comprising a third capacitor in series with the means for connecting.

17. The apparatus of claim 16, wherein the third capacitor is configured to compensate for an additional reactive loading present in the first configuration.

18. The apparatus of claim 15, wherein the means for connecting is not part of a resonant path.

19. The apparatus of claim 15, further comprising means for connecting selectively connecting the first capacitor in one of the first and second configuration based on a coupling between the transmit antenna and a receiver.

20. The apparatus of claim 19, further comprising means for connecting measuring the coupling between the transmit antenna and the receiver, and means for connecting comparing the coupling to a threshold.

21. The apparatus of claim 15, further comprising a multi-tap transformer configured to operate at a first turns-ratio in the first configuration and a second turns-ratio in the second configuration, the first turns-ratio being higher than the second turns-ratio.

22. A non-transitory computer-readable medium comprising code that, when executed, causes an apparatus to:

generate, at a transmit antenna, a field for wireless transmit power in both a first and second configuration;

selectively connect a first capacitor in one of the first and second configuration, the first capacitor being in series with the transmit antenna in the first configuration and in parallel with the transmit antenna in the second configuration; and

connect the first capacitor in parallel with a second capacitor in the first configuration and in series with the second capacitor in the second configuration, the second capacitor in parallel with the transmit antenna.

23. The medium of claim 22, wherein the apparatus comprises a third capacitor in series with at least one switch.

24. The medium of claim 23, wherein the third capacitor is configured to compensate for an additional reactive loading present in the first configuration.

25. The medium of claim 22, wherein said connecting is via at least one switch not part of a resonant path.

26. The medium of claim 22, further comprising code that, when executed, causes the apparatus to selectively connect the first capacitor in one of the first and second configuration based on a coupling between the transmit antenna and a receiver.

27. The medium of claim 26, further comprising code that, when executed, causes the apparatus to measure the coupling between the transmit antenna and the receiver, and to compare the coupling to a threshold.

28. The medium of claim 22, further comprising code that, when executed, causes the apparatus to configure a multi-tap transformer to operate at a first turns-ratio in the first configuration and a second turns-ratio in the second configuration, the first turns-ratio being higher than the second turns-ratio.