WIRELESS POWER TRANSMITTER, WIRELESS POWER RECEIVER, AND METHOD FOR WIRELESS POWER TRANSFER USING THEM

• US 20120025622A1
• Filed: 10/04/2010
• Published: 02/02/2012
• Est. Priority Date: 07/29/2010
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: KIM, Yong Hae, Kang, Seung Youl, Cheon, Sang Hoon, Lee, Myung Lae, Zyung, Tae Hyoung
• Granted Patent: US 8,558,412 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

Provided is a method for a wireless power transfer. The method includes modulating a transmission frequency according to a predetermined value at a wireless power transmitter; and transmitting a high frequency signal according to the modulated transmission signal from the wireless power transmitter to at least one wireless power receiver and redetermining the predetermined value according to information which corresponds to a power value of the high frequency signal received by the at least one wireless power receiver, wherein the modulating the transmission frequency at the wireless power transmitter and transmitting the high frequency and the redetermining the predetermined value the at least one wireless power receiver are repeated.

Claims

1. A method for a wireless power transfer, comprising:

modulating a transmission frequency according to a predetermined value at a wireless power transmitter; and

transmitting a high frequency signal according to the modulated transmission frequency from the wireless power transmitter to at least one wireless power receiver and redetermining the predetermined value according to information which corresponds to a power value of the high frequency signal received by the at least one wireless power receiver,

wherein the modulating the transmission frequency at the wireless power transmitter and transmitting the high frequency and the redetermining the predetermined value the at least one wireless power receiver are repeated.

2. The method of claim 1, wherein the transmission frequency is modulated within approximately 10% of an independent resonance frequency.

3. The method of claim 1, wherein the information about the power value is included in a feedback signal generated by the at least one wireless power receiver.

4. The method of claim 3, the feedback signal is generated by an amplitude modulation method.

5. The method of claim 4, wherein operations are repeatedly performed at the at least one wireless power transmitter, the operations comprising:

transmitting the feedback signal; and

generating a direct current power by using the transmitted high frequency signal and driving a load by using the generated direct current power.

6. The method of claim 5, wherein the transmitting the feedback signal and the modulating the transmission frequency are simultaneously performed.

7. The method of claim 6, wherein the generating the direct current power and driving the load is performed at the same time as the determining the transmission frequency and generating the high frequency signal.

8. The method of claim 7, wherein the transmission frequency is modulated according to the number of wireless power receivers.

9. The method of claim 7, wherein the transmission frequency is modulated according to positions of wireless power receivers.

10. A wireless power transmitter, comprising:

a power generation unit configured to receive an alternating current power and generate a high frequency direct current power;

a frequency modulation unit configured to determine and modulate a transmission frequency of the high frequency direct current power based on a feedback signal received from at least one wireless power receiver; and

a transmission coil unit configured to transmit the high frequency direct current power as a non-radiative electromagnetic wave.

11. The wireless power transmitter of claim 10, wherein the feedback signal includes information which corresponds to a power value inputted to the at least one wireless power receiver.

12. The wireless power transmitter of claim 10, wherein the transmission coil unit comprises:

a power coil where a current corresponding to the high frequency direct current power flows; and

a transmission coil configured to magnetically induce the current flown through the power coil and generate the non-radiative electromagnetic wave when a resonance frequency is the same as the at least one wireless power receiver.

13. The wireless power transmitter of claim 10, further comprising an output time adjustment unit configured to vary a power quantity transmitted when the frequency modulation unit determines the transmission frequency and a power quantity transmitted after the frequency modulation unit determines the transmission frequency.

14. The wireless power transmitter of claim 13, wherein the output time adjustment unit transfers the power by a Pulse Width Modulation (PWM) method.

15. A wireless power receiver, comprising:

a reception coil unit configured to receive a high frequency signal;

a power generation unit configured to generate a direct current power by using an alternating current power received by the reception coil unit;

a load unit configured to be driven by the generated direct current power; and

a feedback signal generation unit configured to generate a feedback signal which corresponds to a power value of the received high frequency signal,

wherein the high frequency signal has a transmission frequency modulated according to the feedback signal.

16. The wireless power receiver of claim 15, wherein the high frequency signal is a non-radiative electromagnetic wave.

17. The wireless power receiver of claim 16, wherein the reception coil unit comprises:

a reception coil through which a high frequency current is flown by receiving the high frequency signal; and

a load coil configured to be magnetically induced according to the high frequency current flow of the reception coil.

18. The wireless power receiver of claim 17, wherein the feedback signal generation unit generates the feedback signal by an amplitude modulation method.

19. The wireless power receiver of claim 18, wherein the feedback signal is a digital signal which corresponds to the power value.