WIRELESS POWER TRANSMISSION APPARATUS, WIRELESS POWER RECEPTION APPARATUS, AND WIRELESS POWER TRANSMISSION AND RECEPTION SYSTEM

• US 20140191586A1
• Filed: 09/21/2011
• Published: 07/10/2014
• Est. Priority Date: 09/21/2011
• Status: Abandoned Application

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ichikawa, Shinji
• Application Number:
  US14/234,553
• Publication Number:
  US 20140191586A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: B60L 53/39 with position-responsive activation of primary coils
• 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 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• 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: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• 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

A wireless power transmission apparatus includes: first coils receiving electric power from an AC power supply for transmitting the electric power to a power reception apparatus; and a controller selecting, from the first coils, a coil to be used for transmission of electric power to the power reception apparatus, based on a position of the power reception apparatus. The first coils are each configured to be switchable between a first state in which electric power can be transmitted to the power reception apparatus and a second state in which efficiency in transmission of electric power to the power reception apparatus is lower than the first state. The controller sets a coil in the first state that is selected to be used for transmission of electric power, and sets a coil in the second state that is not to be used for transmission of electric power

Claims

1. A wireless power transmission apparatus comprising:

a plurality of first coils receiving electric power from an AC power supply for transmitting the electric power to a power reception apparatus; and

a controller selecting, from said plurality of first coils, a coil to be used for transmission of electric power to said power reception apparatus, based on a position of said power reception apparatus,

said plurality of first coils each being configured to be switchable between a first state in which electric power can be transmitted to said power reception apparatus and a second state in which efficiency in transmission of electric power to said power reception apparatus is lower than said first state, and

said controller setting a coil in said first state that is selected to be used for transmission of electric power, and setting a coil in said second state that is not to be used for transmission of electric power.

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

said plurality of first coils are each configured to have a variable capacitance, and

said controller switches each of said plurality of first coils between said first state and said second state by varying the capacitance.

3. The wireless power transmission apparatus according to claim 2, wherein said plurality of first coils each include at least one of a capacitor having a capacitance which can be varied by said controller, and a switch capable of disconnecting the capacitance in accordance with said controller.

4. The wireless power transmission apparatus according to claim 2, further comprising at least one second coil connected to said AC power supply, wherein

said second coil is formed by one electrically conductive wire and one said second coil is provided commonly to said plurality of first coils.

5. The wireless power transmission apparatus according to claim 4, wherein said second coil transmits electric power by electromagnetic induction to said plurality of first coils.

6. The wireless power transmission apparatus according to claim 2, wherein

said plurality of first coils include:

a capacitor provided commonly to said plurality of first coils;

a plurality of coil bodies; and

selection switches selectively connecting said capacitor to one of a corresponding coil body of said plurality of coil bodies.

7. The wireless power transmission apparatus according to claim 1, wherein each of said plurality of first coils is adjusted to have the same natural frequency as a coil included in said power reception apparatus when said each of said plurality of first coils is in said first state, and adjusted to have a different natural frequency from the coil included in said power reception apparatus when said each of said plurality of first coils is in said second state.

8. The wireless power transmission apparatus according to claim 1, wherein each of said plurality of first coils is adjusted so that a difference in natural frequency between said each of said plurality of first coils and a coil included in said power reception apparatus is ±

10% or less when said each of said plurality of first coils is in said first state, and so that said difference is larger than ±

10% when said each of said plurality of first coils is in said second state.

9. The wireless power transmission apparatus according to claim 8, wherein a coupling coefficient between each of said plurality of first coils and the coil included in said power reception apparatus is 0.1 or less when said each of said plurality of first coils is in said first state.

10. The wireless power transmission apparatus according to claim 8, wherein said coil selected to be used for transmission of electric power transmits electric power to said power reception apparatus through at least one of a magnetic field formed between said power reception apparatus and said wireless power transmission apparatus and oscillates at a particular frequency, and an electric field formed between said power reception apparatus and said wireless power transmission apparatus and oscillates at a particular frequency.

11. The wireless power transmission apparatus according to claim 1, wherein said plurality of first coils are arranged along a predetermined direction at a pitch smaller than a coil diameter of said plurality of first coils.

12. The wireless power transmission apparatus according to claim 1, wherein said plurality of first coils are arranged along a predetermined direction at a pitch smaller than a half of a coil diameter of said plurality of first coils.

13. A wireless power reception apparatus comprising:

a plurality of first coils receiving electric power from a power transmission apparatus for transmitting the electric power to an electrical load; and

a controller selecting, from said plurality of first coils, a coil to be used for reception of electric power from said power transmission apparatus, based on a position of said power transmission apparatus,

said plurality of first coils each being configured to be switchable between a first state in which electric power can be received from said power transmission apparatus and a second state in which efficiency in reception of electric power from said power transmission apparatus is lower than said first state, and

said controller setting a coil in said first state that is selected to be used for reception of electric power, and setting a coil in said second state that is not to be used for reception of electric power.

14. The wireless power reception apparatus according to claim 13, wherein

said plurality of first coils are each configured to have a variable capacitance, and

said controller switches each of said plurality of first coils between said first state and said second state by varying the capacitance.

15. The wireless power reception apparatus according to claim 13, wherein each of said plurality of first coils is adjusted so that a difference in natural frequency between said each of said plurality of first coils and a coil included in said power transmission apparatus is ±

10% or less when said each of said plurality of first coils is in said first state, and so that said difference is larger than ±

10% when said each of said plurality of first coils is in said second state.

16. The wireless power reception apparatus according to claim 15, wherein a coupling coefficient between each of said plurality of first coils and the coil included in said power transmission apparatus is 0.1 or less when said each of said plurality of first coils is in said first state.

17. The wireless power reception apparatus according to claim 15, wherein said coil selected to be used for reception of electric power receives electric power from said power transmission apparatus through at least one of a magnetic field formed between said power transmission apparatus and said wireless power reception apparatus and oscillates at a particular frequency, and an electric field formed between said power transmission apparatus and said wireless power reception apparatus and oscillates at a particular frequency.

18. The wireless power reception apparatus according to claim 13. wherein said plurality of first coils are arranged at a pitch smaller than a half of a coil diameter of said plurality of first coils.

19. A wireless power transmission and reception system comprising:

a power reception; and

a wireless power transmission apparatus, said wireless power transmission apparatus including;

a plurality of first coils receiving electric power from an AC power supply for transmitting the electric power to said power reception apparatus; and

a controller selecting, from said plurality of first coils, a coil to be used for transmission of electric power to said power reception apparatus, based on a position of said power reception apparatus,

said plurality of first coils each being configured to be switchable between a first state in which electric power can be transmitted to said power reception apparatus and a second state in which efficiency in transmission of electric power to said power reception apparatus is lower than said first state, and

said controller setting a coil in said first state that is selected to be used for transmission of electric power, and setting a coil in said second state that is not to be used for transmission of electric power.

20. A wireless power transmission and reception system comprising:

a power transmission apparatus; and

a wireless power reception apparatus, said wireless power reception apparatus including;

a plurality of first coils receiving electric power from said power transmission apparatus for transmitting the electric power to an electrical load; and

a controller selecting, from said plurality of first coils, a coil to be used for reception of electric power from said power transmission apparatus, based on a position of said power transmission apparatus,

said plurality of first coils each being configured to be switchable between a first state in which electric power can be received from said power transmission apparatus and a second state in which efficiency in reception of electric power from said power transmission apparatus is lower than said first state, and

said controller setting a coil in said first state that is selected to be used for reception of electric power, and setting a coil in said second state that is not to be used for reception of electric power.