DEVICE ALIGNMENT AND IDENTIFICATION IN INDUCTIVE POWER TRANSFER SYSTEMS

• US 20140015328A1
• Filed: 02/19/2013
• Published: 01/16/2014
• Est. Priority Date: 07/16/2012
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Beaver, Jonathan, Keeling, Nicholas A., Kissin, Michael, van Boheemen, Edward L.
• Granted Patent: US 9,859,755 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• 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 53/305 Communication interfaces
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/37 using optical position determination, e.g. using cameras
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: B60L 53/39 with position-responsive activation of primary coils
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• 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 10/72 Electric energy management in electromobility
• 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 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

This disclosure provides systems, methods and apparatus for wireless power transfer and particularly wireless power transfer to remote systems such as electric vehicles. In one aspect, a wireless power receiver includes a first inductive element, a power supply, and a communication receiver. The first inductive element is configured to receive wireless power from a first electromagnetic field generated by a wireless power transmitter including a second inductive element. The power supply is configured to supply a current to the first inductive element to generate a second electromagnetic field and induce a current in the second inductive element. The communication receiver is configured to receive an indication of a distance between the first inductive element and the second inductive element based on the induced current in the second inductive element.

Claims

1. A wireless power receiver comprising:

a first inductive element configured to receive wireless power from a first electromagnetic field generated by a wireless power transmitter comprising a second inductive element;

a power supply configured to supply a current to the first inductive element to generate a second electromagnetic field and induce a current in the second inductive element; and

a communication receiver configured to receive an indication of a distance between the first inductive element and the second inductive element based on the induced current in the second inductive element.

2. The wireless power receiver of claim 1, further comprising an alignment controller configured to align the wireless power receiver with the wireless power transmitter based on the indication before the wireless power transmitter initiates wireless power transfer to the wireless power receiver.

3. The wireless power receiver of claim 1, wherein the indication comprises a value indicative of a magnitude of the induced current.

4. The wireless power receiver of claim 1, further comprising a communication transmitter configured to notify the wireless power transmitter before the power supply supplies the current to the first inductive element to generate the second electromagnetic field.

5. The wireless power receiver of claim 1, further comprising a display configured to display the indication.

6. The wireless power receiver of claim 5, wherein the display comprises a user interface configured to assist in aligning the wireless power receiver with the wireless power transmitter.

7. The wireless power receiver of claim 1, wherein the communication receiver is further configured to continuously receive the indication from the wireless power transmitter.

8. A wireless power transmitter comprising:

a first inductive element configured to generate a first electromagnetic field for transferring wireless power to a wireless power receiver comprising a second inductive element;

a detector configured to detect an induced current in the first inductive element and determine an indication of a distance between the first inductive element and the second inductive element based on the induced current, the induced current induced in the first inductive element by a second electromagnetic field generated by a current in the second inductive element; and

a communication transmitter configured to transmit the indication to the wireless power receiver.

9. The wireless power transmitter of claim 8, wherein the detector is further configured to measure a magnitude of the induced current, and the indication comprises a value indicative of the measured magnitude of the induced current.

10. The wireless power transmitter of claim 8, further comprising a communication receiver configured to receive a notification from the wireless power receiver, the notification notifying the wireless power transmitter before the current is supplied to the second inductive element to generate the second electromagnetic field.

11. The wireless power transmitter of claim 8, wherein the communication transmitter is further configured to continuously transmit the indication to the wireless power receiver.

12. A method of operating a wireless power receiver, the method comprising:

supplying a current to a first inductive element to generate an electromagnetic field and induce a current in a second inductive element of a wireless power transmitter; and

receiving an indication of a distance between the first inductive element and the second inductive element based on the induced current in the second inductive element.

13. The method of claim 12, further comprising aligning the wireless power receiver with the wireless power transmitter based on the indication before the wireless power transmitter initiates wireless power transfer to the wireless power receiver.

14. The method of claim 12, wherein the indication comprises a value indicative of a magnitude of the induced current.

15. The method of claim 12, further comprising notifying the wireless power transmitter before supplying the current to the first inductive element to generate the electromagnetic field.

16. The method of claim 12, further comprising displaying the indication.

17. The method of claim 15, wherein said displaying the indication comprises displaying the indication on a user interface to assist in aligning the wireless power receiver with the wireless power transmitter.

18. The method of claim 12, further comprising continuously receiving the indication from the wireless power transmitter.

19. A method of operating a wireless power transmitter, the method comprising:

detecting an induced current in a first inductive element, the induced current induced in the first inductive element by an electromagnetic field generated by a current in a second inductive element, a wireless power receiver comprising the second inductive element;

determining an indication of a distance between the first inductive element and the second inductive element based on the induced current; and

transmitting the indication to the wireless power receiver.

20. The method of claim 19, further comprising measuring a magnitude of the induced current, wherein the indication comprises a value indicative of the measured magnitude of the induced current.

21. The method of claim 19, further comprising receiving a notification from the wireless power receiver, the notification notifying the wireless power transmitter before the current is supplied to the second inductive element to generate the electromagnetic field.

22. The method of claim 19, further comprising continuously transmitting the indication to the wireless power receiver.

23. A wireless power receiver comprising:

means for receiving wireless power from a first electromagnetic field generated by a wireless power transmitter comprising a second inductive element of a wireless power transmitter;

means for supplying a current to the means for receiving wireless power from the first electromagnetic field to generate a second electromagnetic field and induce a current in the second inductive element; and

means for receiving an indication of a distance between the means for receiving wireless power and the second inductive element based on the induced current in the second inductive element.

24. The wireless power receiver of claim 23, further comprising means for aligning the wireless power receiver with the wireless power transmitter based on the indication before the wireless power transmitter initiates wireless power transfer to the wireless power receiver.

25. The wireless power receiver of claim 23, further comprising means for displaying the indication to assist in aligning the wireless power receiver with the wireless power transmitter.

26. A wireless power transmitter comprising:

means for generating a first electromagnetic field for transferring wireless power to a wireless power receiver comprising a second inductive element;

means for detecting an induced current in the means for generating the first electromagnetic field, the induced current induced in the means for generating the first electromagnetic field by a second electromagnetic field generated by a current in the second inductive element;

means for determining an indication of a distance between the means for generating the first electromagnetic field and the second inductive element based on the induced current; and

means for transmitting the indication to the wireless power receiver.

27. The wireless power transmitter of claim 26, further comprising means for measuring a magnitude of the induced current, wherein the indication comprises a value indicative of the measured magnitude of the induced current.

28. The wireless power transmitter of claim 27, further comprising means for receiving a notification from the wireless power receiver, the notification notifying the wireless power transmitter before the current is supplied to the second inductive element to generate the second electromagnetic field.

29. A non-transitory, computer-readable medium comprising instructions that when executed cause a processor to perform a method of:

supplying a current to a first inductive element to generate a first electromagnetic field and induce a current in a second inductive element of a wireless power transmitter;

receiving an indication of a distance between the first inductive element and the second inductive element based on the induced current in the second inductive element; and

receiving with the first inductive element wireless power from a second electromagnetic field generated by the second inductive element.

30. A non-transitory, computer-readable medium comprising instructions that when executed cause a processor to perform a method of:

detecting an induced current in a first inductive element, the induced current induced in the first inductive element by a first electromagnetic field generated by a current in a second inductive element, a wireless power receiver comprising the second inductive element;

determining an indication of a distance between the first inductive element and the second inductive element based on the induced current;

transmitting the indication to the wireless power receiver; and

generating a second electromagnetic field for transferring wireless power to the second inductive element.

31. A wireless power receiver comprising:

a first inductive element configured to receive wireless power from a first electromagnetic field generated by a wireless power transmitter comprising a second inductive element; and

a power supply configured to

supply a current to the first inductive element to generate a second electromagnetic field to induce a current in the second inductive element so that the wireless power transmitter determines that the wireless power receiver is in a position suitable for receiving wireless power from the wireless power transmitter, and

selectively receive power from or provide power to the first inductive element.

32. The wireless power receiver of claim 31, further comprising an H bridge connecting the power supply to the first inductive element.

33. The wireless power receiver of claim 31, wherein the power supply comprises a battery configured to receive power during wireless power transfer from the wireless power transmitter to the wireless power receiver.

34. The wireless power receiver of claim 31, wherein the power supply comprises an auxiliary power supply.

35. The wireless power receiver of claim 34, further comprising a transformer configured to couple the auxiliary power supply to a circuit comprising the first inductive element.

36. The wireless power receiver of claim 35, wherein the transformer comprises a voltage transformer.

37. The wireless power receiver of claim 35, wherein the transformer comprises a current transformer.

38. The wireless power receiver of claim 34, wherein the auxiliary power supply comprises a tuning circuit.

39. A wireless power receiver comprising:

means for receiving wireless power from a first electromagnetic field generated by a wireless power transmitter comprising a second inductive element;

means for supplying a current to the means for receiving wireless power to generate a second electromagnetic field to induce a current in the second inductive element so that the wireless power transmitter determines that the wireless power receiver is in a position suitable for receiving wireless power from the wireless power transmitter; and

means for selectively receiving power from or providing power to the means for receiving wireless power.

40. The wireless power receiver of claim 39, wherein said means for selectively receiving or providing power comprises an H bridge.

41. The wireless power receiver of claim 39, wherein said means for supplying the current comprises an auxiliary power supply.