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

• US 20120326522A1
• Filed: 06/22/2012
• Published: 12/27/2012
• Est. Priority Date: 06/22/2011
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: FUKUSHIMA, Noriyuki
• Granted Patent: US 9,160,176 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 5/005 without mechanical contact between the collector and the power supply line
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: H01F 27/006 with special arrangement or spacing of turns of the winding(s), e.g. to produce desired self-resonance
• 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 50/502 the energy repeater being integrated together with the emitter or the receiver
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

To increase efficiency of wireless power feeding to a moving object in wireless power feeding. A wireless power feeder 116 feeds power by wireless from a plurality of feeding coils L2 to an EV 108 including a receiving coil L3. The feeding coils L2 are arranged along a moving direction of the EV 108 and receive power from a power supply circuit including a plurality of power transmission control circuits 200. The power supply circuit 102 makes a first feeding coil L2 supply AC power to the EV 108 when the EV 108 passes through the first feeding coil L2 and, at the same time, prepares power feeding from a second feeding coil L2 through which the EV 108 has not passed.

Claims

1. A wireless power feeder that feeds power by wireless from a feeding coil to a moving object including a receiving coil, comprising:

a plurality of feeding coils arranged along a moving direction of the moving object; and

a power supply circuit supplying AC power to the plurality of feeding coils,

the power supply circuit making a first feeding coil supply AC power to the moving object when the moving object passes through the first feeding coil and preparing power feeding from a second feeding coil through which the moving object has not passed.

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

the second feeding coil is a feeding coil through which the moving object will pass within a predetermined time from when the moving object has passed through the first feeding coil.

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

the power supply circuit selects the second feeding coil based on a current position of the moving object.

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

the plurality of feeding coils are adjacently arranged such that coil surfaces thereof partly overlap each other.

5. The wireless power feeder according to claim 1, further comprising a signal receiving unit receiving a power feeding request signal from the moving object, wherein

the power supply circuit prepares power feeding from the second feeding coil when the signal receiving unit receives the power feeding request signal.

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

the signal receiving unit receives a power feeding stop signal from the moving object, and

the power supply circuit stops power feeding from the second feeding coil when the signal receiving unit receives the power feeding stop signal.

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

the power supply circuit includes a first power transmission control circuit supplying AC power to the first feeding coil and a second power transmission control circuit supplying AC power to the second feeding coil,

the first power transmission control circuit transmits the power feeding request signal to the second power transmission control circuit when supplying AC power to the first feeding coil, and

the second power transmission control circuit prepares power feeding from the second feeding coil when receiving the power feeding request signal.

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

the first power transmission control circuit transmits a power feeding condition of the first feeding coil to the second power transmission control circuit, and

the second power transmission control circuit supplies AC power from the second feeding coil according to the power feeding condition.

9. A wireless power receiver which is a moving object that receives, at a receiving coil, AC power fed by wireless from a feeding coil, comprising:

a receiving coil;

a loading coil magnetically coupled to the receiving coil and receiving the AC power that the receiving coil has received from the feeding coil; and

a signal transmitting unit transmitting, while the wireless power receiver is receiving power from a first feeding coil of a plurality of feeding coils arranged along a moving direction thereof, a power feeding request signal for requesting power feeding to a second feeding coil located next to the first feeding coil.

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

the loading coil is connected with a secondary battery, and

the secondary battery is charged with the AC power that has been supplied to the loading coil.

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

the signal transmitting unit does not require the second feeding coil to feed power when a charging ratio of the secondary battery is equal to or higher than a predetermined threshold value.

12. A wireless power transmission system for feeding power by wireless from a feeding coil to a moving object including a receiving coil, comprising:

a wireless power feeder; and

a wireless power receiver formed as the moving object,

the wireless power feeder including a plurality of feeding coils arranged along a moving direction of the moving object and a power supply circuit supplying AC power to the plurality of feeding coils,

the wireless power receiver including a receiving coil and a loading coil magnetically coupled to the receiving coil and receiving the AC power that the receiving coil has received from the feeding coil,

the power supply circuit making a first feeding coil supply AC power to the moving object when the moving object passes through the first feeding coil and preparing power feeding from a second feeding coil through which the moving object has not passed.