WIRELESS POWER TRANSMITTER, WIRELESS POWER RECEIVER, AND POWER TRANSMISSION METHOD OF WIRELESS POWER TRANSMITTING SYSTEM

• US 20130214612A1
• Filed: 02/15/2013
• Published: 08/22/2013
• Est. Priority Date: 02/17/2012
• Status: Active Grant

• Current Assignee: Nera Innovations Limited (Atlantic IP Services Limited)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: BAE, Su Ho
• Granted Patent: US 9,966,998 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transmitter for transmitting power to a wireless power receiver in a wireless scheme includes a transmitting coil configured to transmit power, which is supplied by a power source, to a receiving coil of the wireless power receiver using resonance; and a detecting unit configured to detect a coupling state between the transmitting coil and the receiving coil using an input impedance of the wireless power transmitter.

Claims

1. A wireless power transmitter for transmitting power to a wireless power receiver in a wireless scheme, the wireless power transmitter comprising:

a transmitting coil configured to transmit power, which is supplied by a power source, to a receiving coil of the wireless power receiver using resonance; and

a detecting unit configured to detect a coupling state between the transmitting coil and the receiving coil using an input impedance of the wireless power transmitter.

2. The wireless power transmitter of claim 1, wherein the detecting unit detects the coupling state by measuring the input impedance of the wireless power transmitter after fixing output impedance of the wireless power receiver.

3. The wireless power transmitter of claim 2, further comprising a transmission induction coil coupled with the transmitting coil to transfer the power, which is supplied by a power source, to the transmitting coil using electromagnetic induction,

wherein the detecting unit detects a coupling coefficient between the transmitting coil and the receiving coil using the measured input impedance of the wireless power transmitter and an inductance of the transmission induction coil after the output impedance of the wireless power receiver is removed.

4. The wireless power transmitter of claim 1, wherein the detecting unit detects the coupling state after fixing output impedance of the wireless power receiver, and

transmits information about the coupling state for adjusting impedance of the wireless power receiver to the wireless power receiver through in-band communication or out-of-band communication.

5. The wireless power transmitter of claim 1, wherein the detecting unit detects the coupling state after fixing output impedance of the wireless power receiver, and determines impedance variation information of the wireless power receiver based on the coupling state between the transmitting coil and the receiving coil and transmits the determined impedance variation information to the wireless power receiver.

6. The wireless power transmitter of claim 5, wherein the impedance variation information of the wireless power receiver comprises one of impedance variation information of a reception induction coil coupled with the receiving coil to receive power and impedance variation information of a load side.

7. A wireless power receiver for receiving power from a wireless power transmitter in a wireless scheme, the wireless power receiver comprising:

a receiving coil configured to receive power from a transmitting coil of the wireless power transmitter using resonance; and

an impedance varying unit configured to vary an output impedance of the wireless power receiver in order to detect a coupling state between the transmitting coil and the receiving coil.

8. The wireless power receiver of claim 7, wherein the impedance varying unit comprises a switch for removing the output impedance of the wireless power receiver.

9. The wireless power receiver of claim 7, further comprising a variable reception induction coil configured to vary an inductance based on the coupling state between the transmitting coil and the receiving coil.

10. The wireless power receiver of claim 9, wherein the variable reception induction coil comprises a plurality of inductors connected to each other in series and a plurality of switches connected to the inductors in parallel, respectively.

11. The wireless power receiver of claim 7, further comprising a load impedance varying unit configured to vary an impedance of a load side based on the coupling state between the transmitting coil and the receiving coil.

12. The wireless power receiver of claim 11, wherein the load impedance varying unit comprises one of a Battery Management IC (BMIC) and a DC-DC converter.

13. A wireless power transmission method of a wireless power transmitting system for transferring power to a load side, the wireless power transmitting method comprising:

varying an output impedance of a wireless power receiver;

measuring an input impedance of a wireless power transmitter according to the varied output impedance of the wireless power receiver; and

detecting a coupling state between a transmitting coil of the wireless power transmitter and a receiving coil of the wireless power receiver using the measured input impedance of the wireless power transmitter.

14. The wireless power transmission method of claim 13, wherein the varying of the output impedance of the wireless power receiver comprises fixing the output impedance.

15. The wireless power transmission method of claim 14, wherein the fixing of the output impedance comprises removing the output impedance of the wireless power receiver by shorting a switch connected to the load side in parallel.

16. The wireless power transmission method of claim 15, wherein the detecting of the coupling state comprises detecting a coupling coefficient between the transmitting coil and the receiving coil using the measured input impedance of the wireless power transmitter and inductance of a reception induction coil coupled with the receiving coil after removing the output impedance.

17. The wireless power transmission method of claim 13, further comprising varying an impedance of the load side based on the detected coupling state between the transmitting coil and the receiving coil.

18. The wireless power transmission method of claim 13, further comprising varying an inductance of a reception induction coil transferring the power to the load side based on the detected coupling state between the transmitting coil and the receiving coil.

19. The wireless power transmission method of claim 13, further comprising transmitting information about the detected coupling state to the wireless power receiver through in-band communication or out-of-band communication by the wireless power transmitter.

20. A non-transitory recording medium recorded with a program for executing the wireless power transmission method according to claim 13.