System and method for alignment and compatibility detection for a wireless power transfer system

• US 9,438,064 B2
• Filed: 03/18/2014
• Issued: 09/06/2016
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Keeling, Nicholas Athol, Kissin, Michael Le Gallais, Huang, Chang-Yu, Beaver, Jonathan, Budhia, Mickel Bipin
• Primary Examiner(s): Do, Thuan
• Application Number:
  US14/218,246
• Publication Number:
  US 20150061578A1
• Time in Patent Office: 903 Days
• Field of Search: 320/108
• US Class Current: 1/1
• 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: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• 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 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• 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 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

Systems, methods, and apparatuses for receiving charging power wirelessly are described herein. One implementation may include an apparatus for receiving charging power wirelessly from a charging transmitter having a transmit coil. The apparatus comprises a receiver communication circuit, coupled to a receive coil and to a load. The receiver communication circuit is configured to receive information associated with at least one characteristic of the charging transmitter. The apparatus further comprises a sensor circuit configured to measure a value of a short circuit current or an open circuit voltage associated with the receive coil. The apparatus further comprises a controller configured to compare the value of the short circuit current or the open circuit voltage to a threshold charging parameter set at a level that provides charging power sufficient to charge the load. The controller may be further configured to initiate receiving the charging power from the charging transmitter when the short circuit current or the open circuit voltage associated with the receive coil is greater than or equal to the threshold charging parameter.

Claims

1. An apparatus for receiving charging power wirelessly from a charging transmitter having a transmit coil, the apparatus comprising:

a receiver communication circuit coupled to a receive coil and to a load, configured to receive an indication of a value of at least one characteristic of the charging transmitter;

a sensor circuit configured to measure a value of a short circuit current or an open circuit voltage of the receive coil; and

a controller configured to;

compare the value of the short circuit current or the open circuit voltage to a threshold charging parameter, the threshold set at a level that provides charging power sufficient to charge the load; and

initiate receiving the charging power from the charging transmitter based on the short circuit current or the open circuit voltage of the receive coil being greater than or equal to the threshold charging parameter.

2. The apparatus of claim 1, wherein the threshold charging parameter comprises at least one of a charging current and a charging voltage.

3. The apparatus of claim 1, wherein the threshold charging parameter comprises a value of a charging current multiplied by a value of a maximum transmit coil current and divided by a value of a transmit coil current.

4. The apparatus of claim 1, wherein the sensor circuit is configured to measure the value of the short circuit current or the open circuit voltage induced by a transmit coil current passing through the transmit coil, the transmit coil current having a value that is less than a value of a maximum transmit coil current.

5. The apparatus of claim 1, wherein the indication comprises a value of a transmit coil current of the charging transmitter.

6. The apparatus of claim 5, wherein the indication further comprises a ratio of a value of a maximum transmit coil current to the value of the transmit coil current.

7. The apparatus of claim 5, wherein the controller is further configured to determine a coupling coefficient between the transmit coil and the receive coil based on the value of the transmit coil current and the value of the short circuit current or the open circuit voltage of the receive coil.

8. The apparatus of claim 1, wherein the receiver communication circuit is further configured to transmit an indication to refrain from initiating charging when the controller determines that the short circuit current or the open circuit voltage of the receive coil is less than the threshold charging parameter.

9. The apparatus of claim 1, further comprising a switching circuit configured to short circuit the receive coil or open circuit the receive coil.

10. The apparatus of claim 1, wherein the controller is further configured to determine an operating zone as a geometric area within which the short circuit current or the open circuit voltage of the receive coil is greater than or equal to the threshold charging parameter.

11. The apparatus of claim 1, wherein the controller is further configured to provide to a user interface an indication of compatibility between the receive coil and the charging transmitter when the short circuit current or the open circuit voltage of the receive coil is greater than or equal to the threshold charging parameter.

12. A method of receiving charging power wirelessly, the method comprising:

receiving, by a receiver communication circuit, an indication of a value of at least one characteristic of a charging transmitter;

measuring, by a sensor circuit, a value of an a short circuit current or an open circuit voltage of a receive coil;

comparing, by a controller, the value of the short circuit current or the open circuit voltage to a threshold charging parameter, the threshold set at a level that provides charging power sufficient to charge a load; and

initiating, by the controller, receiving the charging power from the charging transmitter based on the short circuit current or the open circuit voltage of the receive coil being greater than or equal to the threshold charging parameter.

13. The method of claim 12, wherein the threshold charging parameter comprises at least one of a charging current and a charging voltage.

14. The method of claim 12, wherein the threshold charging parameter comprises a value of a charging current multiplied by a value of a maximum transmit coil current and divided by a value of a transmit coil current.

15. The method of claim 12, wherein the short circuit current or the open circuit voltage is induced by a transmit coil current passing through a transmit coil, the transmit coil current having a value that is less than a value of a maximum transmit coil current.

16. The method of claim 12, wherein the indication comprises a ratio of a value of a maximum transmit coil current to the value of a transmit coil current.

17. The method of claim 16, wherein the indication further comprises a ratio of a value of a maximum transmit coil current to the value of the transmit coil current.

18. The method of claim 16, further comprising determining, by the controller, a coupling coefficient between the transmit coil and the receive coil based on the value of the transmit coil current and the value of the short circuit current or the open circuit voltage of the receive coil.

19. The method of claim 12, further comprising transmitting, by the receiver communication circuit, an indication to refrain from initiating charging when the short circuit current or the open circuit voltage of the receive coil is less than the threshold charging parameter.

20. The method of claim 12, further comprising short circuiting, by a switching circuit, the receive coil or open circuiting the receive coil.

21. The method of claim 12, further comprising determining by the controller, an operating zone as a geometric area within which the short circuit current or the open circuit voltage of the receive coil is greater than or equal to the threshold charging parameter.

22. An apparatus for receiving charging power wirelessly, the apparatus comprising:

means for receiving an indication of a value of at least one characteristic of a charging transmitter, the means for receiving the indication being operatively connected to a load;

means for measuring a value of a short circuit current or an open circuit voltage of the means for receiving the indication;

means for comparing the value of the short circuit current or the open circuit voltage to a threshold charging parameter, the threshold set at a level that provides charging power sufficient to charge the load; and

means for initiating receiving the charging power from the charging transmitter based on the short circuit current or the open circuit voltage of the means for receiving the indication being greater than or equal to the threshold charging parameter.

23. The apparatus of claim 22 further comprising means for transmitting an indication to refrain from initiating charging when the short circuit current or the open circuit voltage of the receive coil is less than the threshold charging parameter.

24. The apparatus of claim 22, wherein:

the means for receiving the indication comprises a receiver communication circuit;

the means for measuring a value of the short circuit current or the open circuit voltage comprises a sensor circuit; and

the means for comparing the value of the short circuit current or the open circuit voltage and the means for initiating receiving the charging power comprise a controller.

25. The apparatus of claim 22, wherein the threshold charging parameter comprises at least one of a charging current and a charging voltage.

26. The apparatus of claim 22, wherein the information comprises a ratio of a value of a maximum transmit coil current to a value of a transmit coil current.

27. An apparatus for transmitting charging power wirelessly to a receive coil of a receiver, the apparatus comprising:

a transmit circuit coupled to a transmit coil;

a sensor circuit coupled to the transmit circuit, the sensor circuit configured to measure a value of at least one characteristic of the transmit circuit; and

a communication circuit configured to transmit an indication of the value of the at least one characteristic of the transmit circuit to the receiver, the receiver receiving the indication causing the receiver to determine a threshold charging parameter based on the indication and causing the receiver to initiate receiving the charging power based on a short circuit current or an open circuit voltage of the receive coil being greater than or equal to the threshold charging parameter.

28. The apparatus of claim 27, wherein the at least one characteristic of the transmit circuit comprises a current of the transmit coil, the value of the current of the transmit coil being a percentage of a value of a maximum transmit coil current drivable through the transmit coil.

29. The apparatus of claim 28, wherein the communication circuit is further configured to transmit an indication of the percentage to the receiver.

30. The apparatus of claim 27, wherein:

the communication circuit is further configured to receive an indication from the receiver to initiate charging; and

the transmit circuit is further configured to initiate transmitting the charging power to the receive coil at a level sufficient to charge a load when the communication circuit receives the indication from the receiver to initiate charging.