Wireless power transmitter, wireless power receiver, and method for controlling same

• US 9,859,745 B2
• Filed: 07/10/2013
• Issued: 01/02/2018
• Est. Priority Date: 07/10/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Byun, Kang-Ho, Kim, Nam-Yun, Kwon, Hyuk-Choon, Kim, Ho-Dong, Jun, Hae-Young, Jung, Soo-Yeon, Jung, Hee-Won
• Primary Examiner(s): GRANT, ROBERT J
• Application Number:
  US14/413,375
• Publication Number:
  US 20150180268A1
• Time in Patent Office: 1,637 Days
• Field of Search: 320108
• 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 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection

Abstract

Disclosed is a method for controlling a wireless power transmitter for transmitting charging power to a wireless power receiver. The control method of the present invention comprises the steps of: adjusting the internal impedance of the wireless power transmitter such that the impedance variation occurring when the wireless power receiver is positioned is set to a second impedance variation different from the first impedance variation; applying detection power for detecting the wireless power receiver; detecting the second impedance variation during the application of the detection power so as to detect the wireless power receiver; and changing the impedance variation occurring when the wireless power receiver is positioned from the second impedance variation to the first impedance variation.

Claims

1. A control method of a wireless power transmitter for transmitting charging power to a wireless power receiver, the control method comprising:

adjusting an internal impedance of the wireless power transmitter such that an impedance change occurring when the wireless power receiver is placed is set to a second impedance change different from a first impedance change;

applying detection power for detecting the wireless power receiver;

detecting the second impedance change and detecting the wireless power receiver while applying the detection power; and

changing the impedance change occurring when the wireless power receiver is placed from the second impedance change to the first impedance change,

wherein the second impedance change is larger than the first impedance change.

2. The control method as claimed in claim 1, wherein the adjusting of the internal impedance of the wireless power transmitter comprises connecting an impedance change unit, that changes the impedance change occurring when the wireless power receiver is placed from the first impedance change to the second impedance change, to the wireless power transmitter.

3. The control method as claimed in claim 2, wherein the connecting of the impedance change unit to the wireless power transmitter comprises controlling a switching unit connected to the impedance change unit to be in an on state.

4. The control method as claimed in claim 2, wherein the impedance change unit comprises at least one of at least one passive element and at least one active element.

5. The control method as claimed in claim 1, wherein a wireless power transmission efficiency in a case where the impedance change occurring when the wireless power receiver is placed corresponds to the second impedance change is less than a wireless power transmission efficiency in a case where the impedance change occurring when the wireless power receiver is placed corresponds to the first impedance change.

6. A wireless power transmitter for transmitting charging power to a wireless power receiver, the wireless power transmitter comprising:

an impedance change unit that sets an impedance change occurring when the wireless power receiver is placed to one of a first impedance change and a second impedance change;

a power transmission unit that transmits the charging power to the wireless power receiver; and

a control unit that performs a control operation for setting the impedance change occurring when the wireless power receiver is placed to a second impedance change, applying detection power for detecting the wireless power receiver to the power transmission unit, and changing the impedance change occurring when the wireless power receiver is placed from the second impedance change to the first impedance change, when detecting the second impedance change and detecting the wireless power receiver while applying the detection power,

wherein the second impedance change is larger than the first impedance change.

7. The wireless power transmitter as claimed in claim 6, further comprising a switching unit that connects the impedance change unit to the wireless power transmitter or releases the connection of the impedance change unit to the wireless power transmitter according to an on state or an off state.

8. The wireless power transmitter as claimed in claim 7, wherein the control unit controls the switching unit connected to the impedance change unit to be in the on state, when detecting the wireless power receiver.

9. The wireless power transmitter as claimed in claim 6, wherein the impedance change unit comprises at least one of at least one passive element and at least one active element.

10. The wireless power transmitter as claimed in claim 6, wherein a wireless power transmission efficiency in a case where the impedance change occurring when the wireless power receiver is placed corresponds to the second impedance change is less than a wireless power transmission efficiency in a case where the impedance change occurring when the wireless power receiver is placed corresponds to the first impedance change.

11. A control method of a wireless power receiver for receiving charging power from a wireless power transmitter, the control method comprising:

setting an internal impedance of the wireless power receiver to a second impedance different from a first impedance;

detecting an impedance change condition for changing the internal impedance of the wireless power receiver from the second impedance to the first impedance or receiving an impedance change command from the wireless power transmitter; and

changing the internal impedance of the wireless power receiver from the second impedance to the first impedance when detecting the impedance change condition or receiving the impedance change command,

wherein an impedance change occurring when the wireless power receiver is placed on the wireless power transmitter corresponds to a first impedance change, when the internal impedance of the wireless power receiver corresponds to the first impedance, and

wherein an impedance change occurring when the wireless power receiver is placed on the wireless power transmitter corresponds to a second impedance change, when the internal impedance of the wireless power receiver corresponds to the second impedance, wherein the second impedance change is larger than the first impedance change.

12. The control method as claimed in claim 11, wherein the setting of the internal impedance of the wireless power receiver to the second impedance different from the first impedance comprises connecting an impedance change unit, that causes the internal impedance of the wireless power receiver in a case where the impedance change unit is connected to the wireless power receiver to be the second impedance, to the wireless power receiver.

13. The control method as claimed in claim 12, wherein the connecting of the impedance change unit to the wireless power receiver comprises controlling a switching unit connected to the impedance change unit to be in an on state.

14. The control method as claimed in claim 12, wherein the impedance change unit comprises at least one of at least one passive element and at least one active element.

15. The control method as claimed in claim 11, wherein a wireless power transmission efficiency in the case where the internal impedance of the wireless power receiver corresponds to the second impedance is less than a wireless power transmission efficiency in the case where the internal impedance of the wireless power receiver corresponds to the first impedance.

16. The control method as claimed in claim 11, wherein the impedance change condition corresponds to a condition under which at least one of a temperature value, a voltage value, a current value and a power value at a point of the wireless power receiver exceeds a threshold.

17. A wireless power receiver for receiving charging power from a wireless power transmitter, the wireless power receiver comprising:

an impedance change unit that sets an internal impedance of the wireless power receiver to one of a first impedance and a second impedance different from the first impedance; and

a control unit that changes the internal impedance of the wireless power receiver from the second impedance to the first impedance when detecting an impedance change condition for changing the internal impedance of the wireless power receiver from the second impedance to the first impedance,

wherein an impedance change occurring when the wireless power receiver is placed on the wireless power transmitter corresponds to a first impedance change, when the internal impedance of the wireless power receiver corresponds to the first impedance, and

wherein an impedance change occurring when the wireless power receiver is placed on the wireless power transmitter corresponds to a second impedance change, when the internal impedance of the wireless power receiver corresponds to the second impedance, wherein the second impedance change is larger than the first impedance change.

18. The wireless power receiver as claimed in claim 17, further comprising a switching unit that connects an impedance change unit, that causes the internal impedance of the wireless power receiver in a case where the impedance change unit is connected to the wireless power receiver to be the second impedance, to the wireless power receiver.

19. The wireless power receiver as claimed in claim 18, wherein the control unit controls the switching unit connected to the impedance change unit to be in an on state.

20. The wireless power receiver as claimed in claim 17, wherein the impedance change unit comprises at least one of at least one passive element and at least one active element.

21. The wireless power receiver as claimed in claim 17, wherein a wireless power transmission efficiency in the case where the internal impedance of the wireless power receiver corresponds to the second impedance is less than a wireless power transmission efficiency in the case where the internal impedance of the wireless power receiver corresponds to the first impedance.

22. The wireless power receiver as claimed in claim 17, wherein the impedance change condition corresponds to a condition under which at least one of a temperature value, a voltage value, a current value and a power value at a point of the wireless power receiver exceeds a threshold.

23. A wireless power receiver for receiving charging power from a wireless power transmitter, the wireless power receiver comprising:

an impedance change unit that sets an internal impedance of the wireless power receiver to one of a first impedance and a second impedance different from the first impedance;

a communication unit that receives, from the wireless power transmitter, an impedance change command which changes the internal impedance of the wireless power receiver from the second impedance to the first impedance; and

a control unit that changes the internal impedance of the wireless power receiver from the second impedance to the first impedance when the impedance change command is received,

wherein an impedance change in the wireless power transmitter occurring due to placement of the wireless power receiver on the wireless power transmitter corresponds to a first impedance change, when the internal impedance of the wireless power receiver corresponds to the first impedance,

wherein the impedance change in the wireless power transmitter occurring due to placement of the wireless power receiver on the wireless power transmitter corresponds to a second impedance change, when the internal impedance of the wireless power receiver corresponds to the second impedance, and

wherein the second impedance change is larger than the first impedance change.

24. A wireless power transmitter for transmitting charging power to a wireless power receiver, the wireless power transmitter comprising:

a power transmission unit that transmits the charging power to the wireless power receiver;

a control unit that applies detection power for detecting the wireless power receiver to the power transmission unit, and detects an impedance change and detects the wireless power receiver for a period during which the detection power is applied; and

a communication unit that transmits an impedance change command which changes an internal impedance of the wireless power receiver from a second impedance to a first impedance different from the second impedance, when the wireless power receiver has been detected,

wherein the impedance change occurring due to placement of the wireless power receiver on the wireless power transmitter corresponds to a first impedance change, when the internal impedance of the wireless power receiver corresponds to the first impedance,

wherein the impedance change occurring due to placement of the wireless power receiver on the wireless power transmitter corresponds to a second impedance change, when the internal impedance of the wireless power receiver corresponds to the second impedance, and

wherein the second impedance change is larger than the first impedance change.

25. A control method of a wireless power transmitter for transmitting charging power to a wireless power receiver, the control method comprising:

applying detection power for detecting the wireless power receiver;

detecting an impedance change and detecting the wireless power receiver for a period during which the detection power is applied; and

transmitting an impedance change command which changes an internal impedance of the wireless power receiver from a second impedance to a first impedance different from the second impedance, when the wireless power receiver has been detected,

wherein the impedance change occurring due to placement of the wireless power receiver on the wireless power transmitter corresponds to a first impedance change, when the internal impedance of the wireless power receiver corresponds to the first impedance,

wherein the impedance change occurring due to placement of the wireless power receiver on the wireless power transmitter corresponds to a second impedance change, when the internal impedance of the wireless power receiver corresponds to the second impedance, and

wherein the second impedance change is larger than the first impedance change.