Energy receiver, detection method, power transmission system, detection device, and energy transmitter

• US 9,530,558 B2
• Filed: 07/02/2012
• Issued: 12/27/2016
• Est. Priority Date: 07/05/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakano, Hiroaki, Fukuda, Shinichi, Murayama, Yuji, Fujimaki, Kenichi, Murakami, Tomomichi
• Primary Examiner(s): Berhanu, Samuel
• Assistant Examiner(s): RANKINE, TARIKH KANEM
• Application Number:
  US14/126,969
• Publication Number:
  US 20140125287A1
• Time in Patent Office: 1,639 Days
• Field of Search: 320/108, 307/104
• 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: G01V 3/101 by measuring the impedance of the search coil; by measuring features of a resonant circuit comprising the search coil measuring impedance or characteristics derived therefrom G01R27/00, e.g. quality factor G01R27/26
• 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 50/60 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 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 90/14 Plug-in electric vehicles

Abstract

An energy receiver includes: a power receiver coil configured to wirelessly receive power transmitted from a power transmitter; a detection section configured to detect a foreign object; and a power storage section configured to supply power to the detection section during detection of the foreign object.

Claims

1. An energy receiver comprising:

power receiving circuitry including a receiver coil configured to wirelessly receive power transmitted from a power transmitter;

detection circuitry directly connected to the power receiving circuitry, the detection circuitry comprising a Q factor detection circuit; and

test signal generation circuitry directly connected to the power receiving circuitry;

wherein,

the detection circuitry is configured to determine a plurality of quality factor values for the power receiving circuit using the Q factor detection circuit and the test signal generation circuitry and then compare the determined plurality of quality factor values with a threshold quality factor value to detect presence of a foreign object, wherein when the foreign object is detected power receiving circuitry is configured to stop receiving power transmitted;

a power storage section configured to supply power to the Q factor detection circuit during detection of the foreign object; and

a communications unit in communication with the detection circuitry.

2. The energy receiver of claim 1, further comprising:

a power regulator connected between the power storage section and the detection circuitry.

3. The energy receiver of claim 1, further comprising a control section that activates the detection section during suspension of wireless power transmission to the power receiver coil using power stored in the power storage section.

4. The energy receiver of claim 3, wherein the control section includes an arithmetic processing section and a determination section, the arithmetic processing section configured to (i) calculate the determined quality factor values related to the power receiver circuit, and (ii) output the determined quality factor values to the determination section, the determination section configured to compare the determined quality factor values with the threshold quality factor value and determine whether the foreign object is within a range of the power receiver coil.

5. The energy receiver of claim 4, further comprising:

a memory configured to store the threshold quality factor value,

wherein,

the memory is non-volatile memory in communication with the control section, and

the threshold quality factor value is obtained when the power receiver coil is substantially isolated from the foreign object.

6. The energy receiver of claim 1, further comprising a switch in communication with the power storage device, the switch positioned to (i) connect the power storage device and the power regulator to provide power for detection of the foreign object during suspension of wireless power transmission, and (ii) disconnect the power storage section and the detection section when the foreign object is not being detected.

7. A detection method comprising:

charging a power storage device using power wirelessly received by a power receiver circuit including a power receiver coil;

communicating with a wireless power transmitter to cause power transmitter to not transmit power, and then provide power stored by the power storage device to a detection circuit directly connected the power receiver; and

detecting whether a foreign object is within a range of the power receiver coil by

generating by a test signal generation circuit directly connected to the power receiver one or more test signals having different frequencies and

determining various quality factor values for the power receiver circuit using Q factor detection circuitry within the detection circuit and the one or more test signals having different frequencies, and then comparing the determined quality factor values to a threshold quality factor value; and

stopping power reception of the power receiver when the foreign object is detected.

8. The detection method of claim 7, further comprising:

activating detection circuitry during suspension of wireless power transmission to the power receiver coil using power stored in the power storage section.

9. The detection method of claim 7, wherein:

each test signal has a unique frequency; and

Q factor detection of whether the foreign object is within the range of the power receiver coil Q factor depends on which, if any, of the determined quality factor values exceeds the threshold quality factor value.

10. The detection method of claim 9, wherein the charging of the power section includes receiving power from the power receiver circuit based on power consumed during the determination of the determined quality factor values.

11. The detection method of claim 8, further comprising:

obtaining the threshold quality factor value when the power receiver coil is isolated from the foreign object;

storing the threshold quality factor value in a non-volatile memory in communication with a control section;

calculating each determined quality factor value using an arithmetic processing section of the control section; and

comparing the determined quality factor values with the threshold quality factor value using a determination section of the control section.

12. The detection method of claim 7, wherein the powering of the detection section includes (i) connecting the detection section to the power storage section using a switch so that power is provided to the power storage section during suspension of wireless power transmission for detection of the foreign object, and (ii) disconnecting the power storage section and the detection section when not detecting for the foreign object.

13. A power transmission system comprising a power transmitter configured to wirelessly transmit power to a power receiver, wherein:

the power transmitter includes

(i) a power transmission coil to wirelessly transmit power to the power receiver,

(ii) an AC signal power supply connected to the power transmission coil,

(iii) a power transmitter communications section, and

(iv) a power transmitter control section to control the supply of the AC signal to the power transmission coil in response to a signal transmitted from the power receiver and received via the power transmitter communications section, and

the power receiver includes

(i) power receiving circuitry including a receiver coil configured to wirelessly receive power transmitted from a power transmitter,

(ii) detection circuitry comprising Q factor detection circuitry directly connected to the power receiving circuitry,

(iii) test signal generation circuitry directly connected to power receiving circuitry,

(iv) detection circuitry configured to determine a plurality of quality factor values for the power receiving circuitry using the Q factor detection circuitry and the test signal generation circuitry and then compare the determined plurality of quality factor values with a threshold quality factor value to detect presence of a foreign object, wherein when the foreign object is detected the power receiving circuitry is configured to stop receiving power transmitted,

(v) a power storage section configured to supply power to the detection circuitry during detection of the foreign object, and

(vi) a power receiver communications unit in communication with the detection circuitry.

14. The power transmission system of claim 13, wherein the detection circuitry, the test signal generation circuitry and the power storage section include switches controlled by control circuitry in the detection circuitry.

15. The power transmission system of claim 13, wherein the power receiver control section is configured to cause the power receiver communications controller to communicate a signal to the power transmitter and to activate the detection section during suspension of wireless power transmission between the power transmitter and the power receiver using power stored in the power storage section.

16. The system of claim 13, wherein,

the power receiver includes a memory configured to store the threshold quality factor value, and

the memory is a non-volatile memory in communication with the power receiver control section.

17. The system of claim 13, wherein the power receiver includes a switch in communication with the power storage section, the switch coupled to (i) connect the power storage device to transfer power to the power regulator to provide power during suspension of wireless power transmission between the power transmitter and the power receiver during activation of the detection section, and (ii) disconnect the power storage device and when the detection section is not activated.

18. A detection device comprising:

power receiving circuitry including a power receiver coil configured to wirelessly receive power transmitted from a power transmitter;

detection circuitry comprising Q factor detection circuitry directly connected to the power receiving circuitry;

test signal generation circuitry capable of generating test signals at different frequencies;

detection circuitry configured to determine a plurality of quality factor values for the power receiving section using the Q factor detection circuitry and test signals having different frequencies and to compare the determined quality factor values with a threshold quality factor value to detect presence of a foreign object, wherein when the foreign object is detected the power receiving circuitry is configured to stop receiving power transmitted; and

a communications unit connected to the detection circuitry.

19. The detection device of claim 18, comprising a power storage section configured to supply power to the detection section during detection of the foreign object, the power storage section having a power storage device that is selectively coupled to the power receiving section and storing power received from the power receiving section.

20. The detection device of claim 19, further comprising a control section configured to activate the detection circuitry during suspension of wireless power transmission to the power receiver coil using power stored in the power storage device.

21. The detection device of claim 19, further comprising:

a memory configured to store the threshold quality factor value obtained when the power receiver coil is isolated from the foreign object; and

the control section in communication with the memory, the control section configured to (i) calculate the determined quality factor values using an arithmetic processing section of the control section, and (ii) compare the determined quality factor values with the threshold quality factor value using a determination section of the control section.

22. The detection device of claim 19, further comprising:

a switch configured to (i) connect the power storage device to cause transfer of power stored on the power storage to the detection circuitry to provide power during suspension of wireless power transmission to the power receiver coil during activation of the detection circuitry, and (ii) disconnect the power storage device when the detection section is not activated.