WIRELESS POWER FEEDER, WIRELESS POWER RECEIVER, AND WIRELESS POWER TRANSMISSION SYSTEM

• US 20110193421A1
• Filed: 04/15/2011
• Published: 08/11/2011
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Urano, Takashi
• Granted Patent: US 8,981,597 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

Abstract

Power is fed from a feeding coil L2 to a receiving coil L3 using magnetic resonance. The receiving coil L3 is connected in series to a capacitor C3 to constitute a receiving coil circuit 130. The receiving coil L3 is further connected to an adjustment coil L5. By adjusting the inductance of the adjustment coil L5, the resonance frequency of the receiving coil circuit 130 can be adjusted. Since the axial direction of the adjustment coil L5 is at right angles to the power feeding direction, an electromotive force does not occur in the adjustment coil L5.

Claims

1. A wireless power feeder that feeds power from a feeding coil to a receiving coil by wireless using a magnetic field resonance phenomenon between the feeding coil and receiving coil, said feeder comprising:

a feeding coil circuit that includes the feeding coil; and

a power supply circuit that supplies AC power to the feeding coil,

the feeding coil circuit further including an adjustment coil whose axial direction is at substantially right angles to the direction of magnetic flux generated by the receiving coil.

2. The wireless power feeder according to claim 1, wherein

the axial direction of the adjustment coil is at substantially right angles to the power feeding direction of the feeding coil.

3. The wireless power feeder according to claim 1, further comprising an exciting circuit including an exciting coil magnetically coupled to the feeding coil, wherein

the exciting circuit supplies the AC power supplied from the AC power supply circuit from the exciting coil to feeding coil.

4. The wireless power feeder according to claim 1, wherein

the adjustment coil has a movable core that moves in its axial direction, and

the inductance of the feeding coil circuit is adjusted by the displacement of the movable core.

5. The wireless power feeder according to claim 1, wherein

the power supply circuit makes the feeding coil that does not substantially resonate with circuit elements on the power feeding side feed the AC power to the receiving coil.

6. The wireless power feeder according to claim 1, wherein

the feeding coil does not form, together with circuit elements on the power feeding side, a resonance circuit having a resonance point corresponding to the resonance frequency of the receiving coil.

7. The wireless power feeder according to claim 1, wherein

no capacitor is connected in series or in parallel to the feeding coil.

8. The wireless power feeder according to claim 1, wherein

the feeding coil circuit resonates at the resonance frequency of the receiving coil.

9. A wireless power receiver that receives, at a receiving coil, AC power fed from a feeding coil by wireless using a magnetic field resonance phenomenon between the feeding coil and receiving coil, said receiver comprising:

a receiving coil circuit that includes a receiving coil and a capacitor; and

a loading circuit that includes a loading coil that is magnetically coupled to the receiving coil to receive the AC power from the receiving coil and a load to which the AC power is supplied from the loading coil,

the receiving coil circuit further including an adjustment coil whose axial direction is at substantially right angles to the direction of magnetic flux generated by the feeding coil.

10. The wireless power receiver according to claim 9, wherein

the axial direction of the adjustment coil is at substantially right angles to the power feeding direction of the feeding coil.

11. The wireless power receiver according to claim 9, wherein

the adjustment coil has a movable core that moves in its axial direction, and

the inductance of the receiving coil circuit is adjusted by the displacement of the movable core.

12. The wireless power receiver according to claim 9, wherein

the receiving coil circuit resonates at the resonance frequency of the feeding coil circuit.

13. A wireless power transmission system for feeding power from a feeding coil to a receiving coil by wireless using a magnetic field resonance phenomenon between the feeding coil and receiving coil, said system comprising:

a feeding coil circuit that includes the feeding coil;

a power supply circuit that supplies AC power to the feeding coil;

a receiving coil circuit that includes a receiving coil and a capacitor; and

a loading circuit that includes a loading coil that is magnetically coupled to the receiving coil to receive the AC power from the receiving coil and a load to which the AC power is supplied from the loading coil,

both or one of the feeding coil circuit and receiving coil circuit have an adjustment coil whose axial direction is at substantially right angles to the power feeding direction of the feeding coil.