Wireless power feeder, wireless power receiver, and wireless power transmission system

• US 8,981,597 B2
• Filed: 04/15/2011
• Issued: 03/17/2015
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Urano, Takashi
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Barnett, Joel
• Application Number:
  US13/087,827
• Publication Number:
  US 20110193421A1
• Time in Patent Office: 1,432 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 wirelessly feeds power from a feeding coil to a receiving coil using a magnetic field resonance phenomenon between the feeding coil and the receiving coil, the feeder comprising:

a feeding coil circuit that includes the feeding coil;

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

a transmission package for accommodating the feeding coil, wherein

the feeding coil circuit further includes;

an adjustment coil whose axial direction is substantially perpendicular to a direction of magnetic flux generated by the receiving coil, the adjustment coil being contained in the transmission package,

a bobbin on which the adjustment coil is wound, the bobbin having a hole extending along the axial direction, an inner surface of the hole having a screw groove, and

a movable core insert having an outer surface with a screw groove to be engaged with the screw groove of the hole for allowing the movable core insert to move in the hole along the axial direction, wherein

the movable core insert comprising;

a cylindrical core case having the outer surface with the screw groove to be engaged with the screw groove of the hole of the bobbin; and

a column-shaped core, without a screw groove, to be inserted in the cylindrical core case.

2. The wireless power feeder according to claim 1, wherein the axial direction of the adjustment coil is substantially perpendicular o a 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 power supply circuit from the exciting coil to the feeding coil.

4. The wireless power feeder according to claim 1, wherein the power supply circuit causes the feeding coil to which no capacitor is connected in series or in parallel, to feed the AC power to the receiving coil.

5. 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.

6. The wireless power feeder according to claim 1, wherein no capacitor is connected in series or in parallel to the feeding coil.

7. The wireless power feeder according to claim 1, wherein the feeding coil circuit resonates at the resonance frequency of the receiving coil.

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

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

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 supply the AC power to a load; and

a receiving package for accommodating the receiving coil, wherein

the receiving coil circuit further includes;

an adjustment coil whose axial direction is substantially perpendicular o a direction of magnetic flux generated by the feeding coil, the adjustment coil being contained in the receiving package,

a bobbin on which the adjustment coil is wound, the bobbin having a hole extending along the axial direction, an inner surface of the hole having a screw groove, and

a movable core insert having an outer surface with a screw groove to be engaged with the screw groove of the hole for allowing the movable core insert to move in the hole along the axial direction, wherein

the movable core insert comprising;

a cylindrical core case having the outer surface with the screw groove to be engaged with the screw groove of the hole of the bobbin; and

a column-shaped core, without a screw groove, to be inserted in the cylindrical core case.

9. The wireless power receiver according to claim 8, wherein the axial direction of the adjustment coil is substantially perpendicular to the power feeding direction of the feeding coil.

10. The wireless power receiver according to claim 8, wherein the receiving coil circuit resonates at the resonance frequency of the feeding coil circuit.

11. A wireless power transmission system for wirelessly feeding power from a feeding coil to a receiving coil using a magnetic field resonance phenomenon between the feeding coil and receiving coil, the 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;

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 supply the AC power to a load;

a first coil package for accommodating one of the feeding coil and the receiving coil, wherein

one of the feeding coil circuit and the receiving coil circuit, having the one of the feeding coil and the receiving coil, includes;

a first adjustment coil whose axial direction is substantially perpendicular to a power feeding direction of the feeding coil, the first adjustment coil being contained in the first coil package,

a first bobbin on which the first adjustment coil is wound, the first bobbin having a hole extending along the axial direction, an inner surface of the hole having a screw groove, and

a first movable core insert having an outer surface with a screw groove to be engaged with the screw groove of the hole for allowing the first movable core insert to move in the hole along the axial direction, wherein

the first movable core insert comprising;

a first cylindrical core case having the outer surface with the screw groove to be engaged with the screw groove of the hole of the first bobbin; and

a first core to be inserted in the first cylindrical core case, the first core having a column shape without a screw groove.

12. The wireless power transmission system according to claim 11, further comprising a second coil package for accommodating the other of the feeding coil and the receiving coil, wherein

the other of the feeding coil circuit and the receiving coil circuit includes:

a second adjustment coil whose axial direction is substantially perpendicular to the power feeding direction of the feeding coil, the second adjustment coil being contained in the second coil package,

a second bobbin on which the second adjustment coil is wound, the second bobbin having a hole extending along the axial direction, an inner surface of the hole having a screw groove, and

a second movable core insert having an outer surface with a screw groove to be engaged with the screw groove of the hole for allowing the second movable core insert to move in the hole along the axial direction.

13. The wireless power transmission system according to claim 12, wherein the second movable core insert comprising:

a second cylindrical core case having the outer surface with the screw groove to be engaged with the screw groove of the hole of the second bobbin; and

a second core to be inserted in the second cylindrical core case.