Wireless power transfer device with foreign object detection, system, and method for performing the same

• US 9,929,605 B2
• Filed: 03/31/2016
• Issued: 03/27/2018
• Est. Priority Date: 06/22/2012
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakano, Hiroaki, Kozakai, Osamu, Komiyama, Shinji, Fujimaki, Kenichi
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): SHIAO, DAVID A
• Application Number:
  US15/088,082
• Publication Number:
  US 20160218567A1
• Time in Patent Office: 726 Days
• Field of Search: None
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• 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: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• 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 50/12 of the resonant type
• 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: H04B 5/26 using coils
• CPC Class Codes: H04B 5/75 for isolation purposes
• 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 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

Methods and apparatus for detecting the presence of undesirable foreign matter in a region between a wireless power transmission apparatus and a power reception apparatus are described. First and second detection methods, based on different detection schemes, may be used to detect and distinguish the presence of foreign matter from misalignment during power transfer operation method may be used while power is supplied to the load.

Claims

1. A power transmitting device comprising:

quality factor measuring circuitry configured to electronically calculate a quality factor of a resonance circuit, a first foreign object detection method is a method that detects a presence of a foreign object or an absence of the foreign object by electronically comparing a first threshold with the quality factor calculated by the quality factor measuring circuitry;

efficiency measuring circuitry configured to electronically calculate a power loss based on an amount of power transmitted by the power transmitting device during a wireless power transfer and an amount of the power received by a power receiving device, a second foreign object detection method is a method that detects the presence of the foreign object or the absence of the foreign object by electronically comparing a second threshold with the power loss calculated by the efficiency measuring circuitry; and

foreign object detection circuitry configured to perform the first foreign object detection method prior to the wireless power transfer and to perform the second foreign object detection method during the wireless power transfer, the power transmitting device is configured to receive the first threshold prior to the wireless power transfer and to transmit the power wirelessly to the power receiving device during the wireless power transfer.

2. The power transmitting device according to claim 1, wherein the power loss indicates an amount of the power that has been lost during the wireless power transfer.

3. The power transmitting device according to claim 1, wherein the power transmitting device is configured to perform an initial power transfer to the power receiving device before performing the first foreign object detection method.

4. The power transmitting device according to claim 1, wherein the foreign object detection circuitry is configured to perform the second foreign object detection method while the power receiving device is providing power to a load.

5. The power transmitting device according to claim 1, wherein the power transmitting device is configured to perform the wireless power transfer based on a result of the first foreign object detection method.

6. The power transmitting device according to claim 1, wherein the power transmitting device is configured to perform the wireless power transfer to the power device when the quality factor is not less than the first threshold.

7. The power transmitting device according to claim 1, wherein the power transmitting device is configured to control the wireless power transfer based on a result of the second foreign object detection method.

8. The power transmitting device according to claim 1, wherein the power transmitting device is configured to terminate the wireless power transfer based on a result of the second foreign object detection method.

9. The power transmitting device according to claim 1, wherein the power transmitting device is configured to terminate the wireless power transfer when the power loss is not higher than the second threshold.

10. A wireless power transfer system comprising:

a power receiving device configured to output a first threshold before a wireless power transfer; and

a power transmitting device configured to receive the first threshold from the power receiving device prior to the wireless power transfer and to transmit power wirelessly to the power receiving device during the wireless power transfer,

wherein the power transmitting device includes;

quality factor measuring circuitry configured to electronically calculate the quality factor of a resonance circuit,

efficiency measuring circuitry configured to electronically calculate a power loss based on an amount of power transmitted by the power transmitting device during the wireless power transfer and an amount of the power received by the power receiving device, and

foreign object detection circuitry configured to perform a first foreign object detection method prior to the wireless power transfer and to perform a second foreign object detection method during the wireless power transfer,

wherein the first foreign object detection method is a method that detects a presence of a foreign object or an absence of the foreign object by electronically comparing the first threshold with the quality factor calculated by the quality factor measuring circuitry, and

wherein the second foreign object detection method is a method that detects the presence of the foreign object or the absence of the foreign object by electronically comparing a second threshold with the power loss calculated by the efficiency measuring circuitry.

11. The wireless power transfer system according to claim 10, wherein the power loss indicates an amount of the power that has been lost during the wireless power transfer.

12. The wireless power transfer system according to claim 10, wherein the power receiving device is configured to provide a reference value to determine the first threshold.

13. The wireless power transfer system according to claim 10, wherein the power receiving device is configured to provide the first threshold.

14. The wireless power transfer system according to claim 10, wherein the transmitting device is configured to terminate the wireless power transfer when the calculated power loss during the wireless power transfer is not higher than the second threshold.

15. The wireless power transfer system according to claim 10, wherein the power transmitting device is configured to perform the wireless power transfer based on a result of the first foreign object detection method.

16. The wireless power transfer system according to claim 10, wherein the power transmitting device is configured to control the wireless power transfer based on a result of the second foreign object detection method.

17. A method of transmitting power, the method comprising:

outputting a first threshold from a power receiving device prior to a wireless power transfer;

receiving the first threshold from the power receiving device by a power transmitting device prior to the wireless power transfer;

electronically calculating the quality factor of a resonance circuit using quality factor measuring circuitry in the power transmitting device;

performing a first foreign object detection method prior to the wireless power transfer using foreign object detection circuitry in the power transmitting device;

transmitting power wirelessly from the power transmitting device to the power receiving device during the wireless power transfer;

electronically calculating a power loss based on an amount of power transmitted by the power transmitting device during the wireless power transfer and an amount of the power received by the power receiving device using efficiency measuring circuitry in the power transmitting device; and

performing a second foreign object detection method during the wireless power transfer using the foreign object detection circuitry,

wherein the first foreign object detection method is a method that detects a presence of a foreign object or an absence of the foreign object by electronically comparing the first threshold with the quality factor calculated by the quality factor measuring circuitry, and

wherein the second foreign object detection method is a method that detects the presence of the foreign object or the absence of the foreign object by electronically comparing a second threshold with the power loss calculated by the efficiency measuring circuitry.

18. The method according to claim 17, wherein the power loss indicates an amount of the power that has been lost during the wireless power transfer.

19. The method according to claim 17, further comprising:

performing an initial transfer of the power to the power receiving device prior to performing the first foreign object detection method by the power transmitting device.

20. The method according to claim 17, wherein the second foreign object detection method is performed while the power receiving device is providing power to a load.

21. The method according to claim 17, wherein the power transmitting device performs the wireless power transfer based on a result of the first foreign object detection method.

22. The method according to claim 17, wherein the power transmitting device performs the wireless power transfer to the power device when the quality factor is not less than the first threshold.

23. The method according to claim 17, further comprising:

controlling the wireless power transfer based on a result of the second foreign object detection method by the power transmitting device.

24. The method according to claim 17, further comprising:

terminating the wireless power transfer based on a result of the second foreign object detection method by the power transmitting device.

25. The method according to claim 17, further comprising:

terminating the wireless power transfer when the power loss is not higher than the second threshold by power transmitting device.