ELECTRIC POWER TRANSMITTING DEVICE, NON-CONTACT POWER SUPPLY SYSTEM, AND CONTROL METHOD

• US 20140375137A1
• Filed: 06/24/2014
• Published: 12/25/2014
• Est. Priority Date: 06/25/2013
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: ICHIKAWA, Katsuei
• Granted Patent: US 10,177,817 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 50/502 the energy repeater being integrated together with the emitter or the receiver
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A non-contact power supply system is provided employing an electric power transmitting device which can improve the transmission efficiency of electric power, suppressing the circuit scale. The electric power transmitting device is configured with a resonance circuit including a resonance capacity and a resonance coil acting as a transmitting antenna, and a first coil arranged magnetically coupled with the resonance coil. The electric power transmitting device transmits electric power in a non-contact manner using resonant coupling of the resonance circuit. When transmitting the electric power, the electric power transmitting device controls the first coil to connect or disconnect both ends thereof so as to bring a resonance frequency of the resonance circuit close to a frequency of an electric power transmission signal outputted as the electric power to be transmitted.

Claims

1. An electric power transmitting device comprising:

a resonance circuit including a resonance capacity and a resonance coil acting as a transmitting antenna;

a first coil arranged magnetically coupled with the resonance coil,

wherein the electric power transmitting device transmits electric power in a non-contact manner with the use of resonant coupling of the resonance circuit, and

wherein, when transmitting the electric power, the first coil is controlled to connect or disconnect both ends thereof so as to bring a resonance frequency of the resonance circuit close to a frequency of an electric power transmission signal outputted as the electric power to be transmitted.

2. The electric power transmitting device according to claim 1, further comprising:

a plurality of the first coils,

wherein each of the first coils is separately controllable in a connection state of connecting or disconnecting both ends thereof.

3. The electric power transmitting device according to claim 2,

wherein each of the first coils has mutually different length and is arranged concentrically surrounding the resonance coil.

4. The electric power transmitting device according to claim 2,

wherein each of the first coils is arranged mutually spaced out in the same plane, so as to overlap with apart of the resonance coil in the height direction.

5. The electric power transmitting device according to claim 4,

wherein each of the first coils is arranged so as to have a substantially equal overlapping part with the resonance coil.

6. The electric power transmitting device according to claim 5,

wherein wireless data communications are possible with one of the first coils acting as an antenna.

7. The electric power transmitting device according to claim 6,

wherein one of the first coils is selectable as the antenna for the wireless data communications.

8. The electric power transmitting device according to claim 7,

wherein the data communications are in conformity with the NFC specifications.

9. The electric power transmitting device according to claim 2, further comprising:

a power supply unit operable to generate an AC signal corresponding to the electric power to be transmitted and operable to supply it to the resonance circuit;

a power sensing unit operable to detect a reflected amount of the AC signal supplied to the resonance circuit from the power supply unit; and

a control unit,

wherein the control unit switches the connection state of the first coil so as to minimize the reflected amount.

10. The electric power transmitting device according to claim 9,

wherein the power sensing unit generates a first voltage corresponding to an incident electric power of the AC signal supplied to the resonance circuit from the power supply unit, and a second voltage corresponding to a reflected electric power of the AC signal, and

wherein the control unit calculates a voltage standing wave ratio on the basis of the first voltage and the second voltage, and determines the magnitude of the reflected amount on the basis of the calculated result.

11. The electric power transmitting device according to claim 2,

wherein the number of turns of the first coil is one turn.

12. The electric power transmitting device according to claim 1,

wherein the first coil is arranged in the same plane with the resonance coil, surrounding the resonance coil.

13. The electric power transmitting device according to claim 12,

wherein electric power is transmitted with both ends of the first coil connected, and

wherein, when it is detected that the resonance frequency is deviated, the electric power is transmitted with both ends of the first coil disconnected.

14. A non-contact power supply system comprising:

the electric power transmitting device according to claim 1; and

an electric power receiving device operable to receive electric power supplied by the electric power transmitting device in a non-contact manner, with the use of electromagnetic resonant coupling utilizing a resonance circuit.

15. An electric power transmitting device comprising:

a resonance circuit including a resonance capacity and a resonance coil acting as a transmitting antenna;

a first repeating circuit including a first capacitor and a first repeating coil arranged magnetically coupled with the resonance coil; and

a first coil arranged magnetically coupled with both the resonance coil and the repeating coil,

wherein the electric power transmitting device transmits electric power in a non-contact manner with the use of resonant coupling between the resonance circuit and the first repeating circuit,

wherein the resonance coil and the first repeating coil are arranged in the same plane, and

wherein the first coil is arranged so as to overlap with both the resonance coil and the first repeating coil in the height direction, and connection or disconnection of both ends of the first coil is switchable.

16. The electric power transmitting device according to claim 15 further comprising:

a second repeating circuit including a second capacitor and a second repeating coil arranged magnetically coupled with the first repeating coil; and

a second coil arranged magnetically coupled with both the first repeating coil and the second repeating coil,

wherein the first repeating coil and the second repeating coil are arranged in the same plane, and

wherein the second coil is arranged so as to overlap with both the first repeating coil and the second repeating coil in the height direction, and connection or disconnection of both ends of the second coil is switchable.

17. The electric power transmitting device according to claim 16, further comprising:

a power supply unit operable to generate an AC signal corresponding to the electric power to be transmitted and operable to supply it to the resonance circuit;

a power sensing unit operable to detect a reflected amount of the AC signal supplied to the resonance circuit from the power supply unit; and

a control unit,

wherein the control unit switches between connection and disconnection of both ends of the first coil and both ends of the second coil, respectively, so as to minimize the reflected amount.

18. A control method for controlling electric power transmission in an electric power transmitting device which comprises:

a resonance circuit including a resonance capacity and a resonance coil acting as a transmitting antenna; and

a plurality of first coils arranged magnetically coupled with the resonance coil, each of the first coils being separately controllable in a connection state of connecting or disconnecting both ends thereof, and which transmits electric power in a non-contact manner with the use of resonant coupling of the resonance circuit, the control method comprising;

a first step in which the electric power transmitting device searches for a combination of the connection state of each of the first coils so as to minimize a reflected amount of an AC signal supplied to the resonance circuit; and

a second step in which the electric power transmitting device transmits electric power in the connection state of the first coils searched in the first step.

19. The control method according to claim 18, further comprising:

a third step in which the electric power transmitting device starts the electric power transmission with a second electric power lower than a first electric power in a state where both ends of each of the first coils are connected;

a fourth step in which the electric power transmitting device estimates the reflected amount when the electric power is transmitted with the second electric power in the state where both ends of each of the first coils are connected;

a fifth step in which the electric power transmitting device determines whether the reflected amount estimated in the fourth step is deviated from a prescribed reference value;

a sixth step in which the electric power transmitting device determines whether the reflected amount is within a prescribed range when it has been determined that the reflected amount is deviated from the prescribed reference value in the fifth step;

a seventh step in which the electric power transmitting device transmits the electric power by changing from the second electric power to the first electric power when it has been determined that the reflected amount is within the prescribed range in the sixth step; and

an eighth step in which the electric power transmitting device stops the electric power transmission when it has been determined that the reflected amount is not within the prescribed range in the sixth step,

wherein the first step is executed after the seventh step.

20. The control method according to claim 19,

wherein the reflected amount is estimated on the basis of a value of the voltage standing wave ratio which is calculated from a first voltage corresponding to an incident electric power of the AC signal supplied to the resonance circuit, and a second voltage corresponding to a reflected electric power of the AC signal.