Wireless power transmission apparatus and wireless power transmission method

1. A wireless power transmission apparatus comprising:

resonators configured to wirelessly transmit first power to a wireless power reception apparatus;

a controller configured to control a current magnitude and/or a voltage magnitude of second power to be provided to each of the resonators; and

a conductor configured to provide the second power to each of the resonators,

wherein the controller is further configured to:

receive, by using a communication unit, information of a voltage and/or a current that are applied to a load of the wireless power reception apparatus;

obtain an efficiency of the wireless power transmission, based on the received information and the current magnitude and/or the voltage magnitude of the second power; and

adjust the current magnitude and/or the voltage magnitude of the second power based on the efficiency of the transmission.

2. The apparatus of claim 1 , wherein the controller is further configured to:

calculate an impedance of an N-port network between the other resonator connected the N-port network and the resonators connected to the N-port network; and

control the current magnitude and/or the voltage magnitude based on the impedance.

3. The apparatus of claim 1 , wherein the resonators are coupled to each other, or separated from each other, and wherein the conductor comprises an inductor.

4. The apparatus of claim 1 , further comprising:

a communication circuit configured to receive, from the wireless power reception apparatus, the information of the voltage and/or the current that are applied to the load of the wireless power reception apparatus in response to a test voltage and a test current being applied to the resonators.

5. The apparatus of claim 4 , wherein the controller comprises:

one or more hardware processors configured to:

calculate an impedance of an N-port network between the other resonator connected the N-port network and the resonators connected to the N-port network, and the efficiency of the transmission, based on the received information of the voltage and/or the current;

optimize the impedance based on a predetermined power transmission efficiency; and

determine the current magnitude and/or the voltage magnitude based on a result of the optimization.

6. The apparatus of claim 5 , wherein the one or more hardware processors is further configured to:

change the current magnitude and/or the voltage magnitude sequentially in a range of the current magnitude and/or the voltage magnitude that is applicable by the conductor.

7. The apparatus of claim 5 , wherein the one or more hardware processors is further configured to:

change the current magnitude and/or the voltage magnitude randomly in a range of the current magnitude and/or the voltage magnitude that is applicable by the conductor.

8. The apparatus of claim 5 , wherein the one or more hardware processors is further configured to:

change the current magnitude and/or the voltage magnitude based on a lookup table in a range of the current magnitude and/or the voltage magnitude that is applicable by the conductor.

9. The apparatus of claim 5 , wherein the one or more hardware processors is further configured to:

estimate an optimal current magnitude and/or an optimal voltage magnitude of the second power of when the efficiency satisfies the predetermined power transmission efficiency, based on the impedance and an N-port matrix relational expression induced in the N-port network.

10. The apparatus of claim 1 , wherein each of the resonators comprises:

a first transmission line comprising a first signal conducting portion, a second signal conducting portion, and a first ground conducting portion corresponding to the first signal conducting portion and the second signal conducting portion;

a first conductor connected to the first signal conducting portion and the first ground conducting portion;

a second conductor connected to the second signal conducting portion; and

a capacitor inserted in series between the first signal conducting portion and the second signal conducting portion with respect to a current flowing through the first signal conducting portion and the second signal conducting portion.

11. A wireless power transmission apparatus comprising:

resonators configured to wirelessly transmit first power to a wireless power reception apparatus;

a controller configured to control a current magnitude and/or a voltage magnitude of a second power to be provided to each of the resonators; and

a conductor configured to provide the second power to each of the resonators, wherein each of the resonators comprises:

a first resonator comprising a surface parallel to an xy plane;

a second resonator comprising a surface parallel to a yz plane; and

a third resonator comprising a surface parallel to a zx plane.

12. A wireless power transmission apparatus comprising:

resonators configured to wirelessly transmit first power to a wireless power reception apparatus;

a controller configured to control a current phase and/or a voltage phase of the power to be provided to each of the resonators; and

a conductor configured to provide the second power to each of the resonators,

wherein the controller is further configured to:

receive, by using a communication unit, information of a voltage and/or a current that are applied to a load of the wireless power reception apparatus;

obtain an efficiency of the wireless power transmission, based on the received information and the current phase and/or the voltage phase of the second power; and

adjust the current phase and/or the voltage phase of the second power based on the efficiency of the transmission.

13. The apparatus of claim 12 , wherein the controller is further configured to:

calculate an impedance of an N-port network between the other resonator connected to the N-port network and the resonators connected to the N-port network; and

control the current phase and/or the voltage phase based on the impedance.

14. The apparatus of claim 12 , further comprising:

a communication circuit configured to receive, from the wireless power reception apparatus, the information of the voltage and/or the current that are applied to the load of the wireless power reception apparatus in response to a test voltage and a test current being applied to the resonators.

15. The apparatus of claim 14 , wherein the controller comprises:

one or more hardware processors configured to: calculate an impedance of an N-port network between the other resonator connected the N-port network and the resonators connected to the N-port network, and the efficiency of the transmission, based on the received information of the voltage and/or the current;

optimize the impedance based on a predetermined power transmission efficiency; and

determine the current phase and/or the voltage phase based on a result of the optimization.

16. A wireless power transmission method comprising:

controlling, by a controller, a current magnitude and/or a voltage magnitude of second power to be provided to each of resonators;

providing, by a conductor, the second power to each of the resonators; and

wirelessly transmitting, by the resonators, first power to a wireless power reception apparatus,

wherein the controlling comprises:

receiving, by using a communication unit, information of a voltage and/or a current that are applied to a load of the wireless power reception apparatus;

obtaining an efficiency of the transmission, based on the received information and the current magnitude and/or the voltage magnitude of the second power; and

adjusting the current magnitude and/or the voltage magnitude of the second power based on the efficiency of the transmission.

17. The method of claim 16 , wherein the controlling comprises:

calculating an impedance of an N-port network between the other resonator connected the N-port network and the resonators connected to the N-port network; and

controlling the current magnitude and/or the voltage magnitude based on the impedance.

18. The method of claim 16 , further comprising:

receiving, from the wireless power reception apparatus, the information of the voltage and/or the current that are applied to the load of the wireless power reception apparatus in response to a test voltage and a test current being applied to the resonators.

19. The method of claim 18 , wherein the controlling comprises:

calculating an impedance of an N-port network between the other resonator connected the N-port network and the resonators connected to the N-port network, and the efficiency of the transmitting, based on the received information of the voltage and/or the current;

optimizing the impedance based on a predetermined power transmission efficiency; and

determining the current magnitude and/or the voltage magnitude based on a result of the optimizing.