WIRELESS POWER TRANSMISSION SYSTEM

• US 20120161541A1
• Filed: 12/21/2011
• Published: 06/28/2012
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: URANO, Takashi
• Granted Patent: US 9,143,010 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 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/37 Converter circuits

Abstract

A wireless power transmission system according to an embodiment of the present invention is a wireless power transmission system performing non-contact power transmission from a wireless power feeder selectively to a plurality of wireless power receivers, and each of the plurality of wireless power receivers comprises a power receive resonance circuit including a power receive coil and a power receive capacitor, and the wireless power feeder comprises a power feed coil and a control circuit supplying AC power to the power feed coil. The control circuit in the wireless power feeder performs power supply selectively to the plurality of wireless power receivers by changing frequency of the AC power on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil.

Claims

1. A wireless power transmission system which performs non-contact power transmission from a wireless power feeder selectively to a plurality of wireless power receivers,

each of the plurality of wireless power receivers comprising a power receive resonance circuit including a power receive coil and a power receive capacitor, and

the wireless power feeder comprising a power feed coil and a control circuit supplying AC power to the power feed coil, wherein

the control circuit in the wireless power feeder performs power feeding selectively to the plurality of wireless power receivers by changing frequency of the AC power on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil.

2. The wireless power transmission system according to claim 1, wherein

the power receive resonance circuits in the plurality of wireless power receivers have resonance frequencies different from one another, respectively, and

a winding region of the power receive coil in each of the plurality of wireless power receivers is smaller than ¼

of a winding region of the power feed coil.

3. The wireless power transmission system according to claim 1, wherein

the power receive resonance circuits in the plurality of wireless power receivers have resonance frequencies different from one another, respectively, and

a winding diameter of the power receive coil in each of the plurality of wireless power receivers is smaller than ½

of a winding diameter of the power feed coil.

4. The wireless power transmission system according to claim 1, wherein

the power receive resonance circuits in the plurality of wireless power receivers have approximately the same resonance frequency,

the power receive coils in the plurality of wireless power receivers are disposed in distances different from one another from the power feed coil, respectively, and

a winding region of the power receive coil in each of the plurality of wireless power receivers is equal to or larger than ¼

of a winding region of the power feed coil.

5. The wireless power transmission system according to claim 1, wherein

the power receive resonance circuits in the plurality of wireless power receivers have approximately the same resonance frequency,

the power receive coils in the plurality of wireless power receivers are disposed in distances different from one another from the power feed coil, respectively, and

a winding diameter of the power receive coil in each of the plurality of wireless power receivers is equal to or larger than ½

of a winding diameter of the power feed coil.

6. The wireless power transmission system according to claim 1, wherein

the power receive resonance circuits in some wireless power receivers among the plurality of wireless power receivers have resonance frequencies different from one another, respectively,

a winding region of the power receive coil in each of the some wireless power receivers is smaller than ¼

of a winding region of the power feed coil,

the power receive resonance circuits in the other wireless power receivers among the plurality of wireless power receivers have approximately the same resonance frequency,

the power receive coils in the other wireless power receivers are disposed in distances different from one another from the power feed coil, respectively, and

a winding region of the power receive coil in each of the other wireless power receivers is equal to or larger than ¼

of a winding region of the power feed coil.

7. The wireless power transmission system according to claim 1, wherein

the power receive resonance circuits in some wireless power receivers among the plurality of wireless power receivers have resonance frequencies different from one another, respectively,

a winding diameter of the power receive coil in each of the some wireless power receivers is smaller than ½

of a winding diameter of the power feed coil,

the power receive resonance circuits in the other wireless power receivers among the plurality of wireless power receivers have approximately the same resonance frequency,

the power receive coils in the other wireless power receivers are disposed in distances different from one another from the power feed coil, respectively, and

a winding diameter of the power receive coil in each of the other wireless power receivers is equal to or larger than ½

of a winding diameter of the power feed coil.

8. The wireless power transmission system according to claim 1, wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.

9. The wireless power transmission system according to claim 1, wherein

the control circuit in the wireless power feeder performs power supply so that AC power having a frequency corresponding to each of the power receive resonance circuits in the plurality of wireless power receivers is supplied to the power receive coil in a time division manner.

10. The wireless power transmission system according to claim 2 wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.

11. The wireless power transmission system according to claim 3, wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.

12. The wireless power transmission system according to claim 4, wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.

13. The wireless power transmission system according to claim 5, wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.

14. The wireless power transmission system according to claim 6, wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.

15. The wireless power transmission system according to claim 7, wherein

the power feed coil in the wireless power feeder substantially does not constitute a resonance circuit.