Wireless electric power feeding equipment

• US 8,581,445 B2
• Filed: 12/01/2010
• Issued: 11/12/2013
• Est. Priority Date: 12/01/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ichikawa, Shinji
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Parries, Dru
• Application Number:
  US13/580,518
• Publication Number:
  US 20130127242A1
• Time in Patent Office: 1,077 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60R 16/00 Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for devices for protecting vehicle occupants in case of accidents B60R21/00; safety belts B60R22/00; central door locking E05B49/00, E05B77/50
• 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
• 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: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• 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

An electric power supply device generates electric power having a prescribed frequency. An electric power transfer unit receives electric power from the electric power supply device, and transfers electric power to an electric power receiving unit in a contactless manner by resonating with the electric power receiving unit via an electromagnetic field. An electric power sensor senses power reflected to the electric power supply device. A discharging coil unit externally discharges electric power output from the electric power supply device. A relay electrically connects the discharging coil unit between the electric power supply device and the electric power transfer unit when the reflected power detected has a value exceeding a predetermined value.

Claims

1. Wireless electric power feeding equipment for feeding electric power in a contactless manner to an electric power receiving device including an electric power receiving unit, comprising:

an electric power supply device generating electric power having a prescribed frequency;

an electric power transfer unit for receiving electric power from said electric power supply device and for transferring the electric power to said electric power receiving unit in a contactless manner by resonating with said electric power receiving unit via an electromagnetic field;

a detection device for detecting power reflected to said electric power supply device;

a discharging device configured of one of a discharging coil for externally discharging electric power output from said electric power supply device and a resistor for consuming electric power output from said electric power supply device; and

a connection device electrically connecting said discharging device between said electric power supply device and said electric power transfer unit when the reflected power detected has a value exceeding a predetermined value.

2. The wireless electric power feeding equipment according to claim 1,

said discharging device being said discharging coil,

the equipment further comprising an electromagnetic shielding material surrounding said discharging coil and also opened only in one direction to allow said discharging coil to externally discharge electric power, wherein:

said discharging coil and said electromagnetic shielding material are provided underground; and

said electromagnetic shielding material is disposed to have an opening facing away from a ground surface.

3. The wireless electric power feeding equipment according to claim 1, further comprising a variable impedance device provided between said electric power supply device and said electric power transfer unit for adjusting an input impedance of a resonance system configured of said electric power transfer unit and said electric power receiving unit, wherein

said connection device electrically connects said discharging device between said variable impedance device and said electric power transfer unit when the reflected power detected has the value exceeding said predetermined value.

4. The wireless electric power feeding equipment according to claim 3, further comprising a controller operative in response to the reflected power detected having the value exceeding said predetermined value for operating said connection device and also modifying said variable impedance device in impedance to have a prescribed value.

5. The wireless electric power feeding equipment according to claim 4, wherein:

said discharging device is said discharging coil; and

said prescribed value is a value previously set to match said discharging coil in impedance to a space surrounding said discharging coil.

6. The wireless electric power feeding equipment according to claim 1, wherein:

said electric power transfer unit includes

a primary coil receiving electric power from said electric power supply device, and

a primary self resonant coil fed with the electric power from said primary coil through electromagnetic induction and generating said electromagnetic field; and

said electric power receiving unit includes

a secondary self resonant coil receiving the electric power from said primary self resonant coil by resonating with said primary self resonant coil via said electromagnetic field, and

a secondary coil extracting through electromagnetic induction and outputting the electric power received by said secondary self resonant coil.

7. The wireless electric power feeding equipment according to claim 1, wherein said electric power receiving device is mounted in a vehicle.

8. The wireless electric power feeding equipment according to claim 2, wherein:

said electric power transfer unit includes

a primary coil receiving electric power from said electric power supply device, and

a primary self resonant coil fed with the electric power from said primary coil through electromagnetic induction and generating said electromagnetic field; and

said electric power receiving unit includes

a secondary self resonant coil receiving the electric power from said primary self resonant coil by resonating with said primary self resonant coil via said electromagnetic field, and

a secondary coil extracting through electromagnetic induction and outputting the electric power received by said secondary self resonant coil.

9. The wireless electric power feeding equipment according to claim 3, wherein:

said electric power transfer unit includes

a primary coil receiving electric power from said electric power supply device, and

a primary self resonant coil fed with the electric power from said primary coil through electromagnetic induction and generating said electromagnetic field; and

said electric power receiving unit includes

a secondary self resonant coil receiving the electric power from said primary self resonant coil by resonating with said primary self resonant coil via said electromagnetic field, and

a secondary coil extracting through electromagnetic induction and outputting the electric power received by said secondary self resonant coil.

10. The wireless electric power feeding equipment according to claim 4, wherein:

said electric power transfer unit includes

a primary coil receiving electric power from said electric power supply device, and

a primary self resonant coil fed with the electric power from said primary coil through electromagnetic induction and generating said electromagnetic field; and

said electric power receiving unit includes

a secondary self resonant coil receiving the electric power from said primary self resonant coil by resonating with said primary self resonant coil via said electromagnetic field, and

a secondary coil extracting through electromagnetic induction and outputting the electric power received by said secondary self resonant coil.

11. The wireless electric power feeding equipment according to claim 5, wherein:

said electric power transfer unit includes

a primary coil receiving electric power from said electric power supply device, and

a primary self resonant coil fed with the electric power from said primary coil through electromagnetic induction and generating said electromagnetic field; and

said electric power receiving unit includes

a secondary self resonant coil receiving the electric power from said primary self resonant coil by resonating with said primary self resonant coil via said electromagnetic field, and

a secondary coil extracting through electromagnetic induction and outputting the electric power received by said secondary self resonant coil.

12. The wireless electric power feeding equipment according to claim 2, wherein said electric power receiving device is mounted in a vehicle.

13. The wireless electric power feeding equipment according to claim 3, wherein said electric power receiving device is mounted in a vehicle.

14. The wireless electric power feeding equipment according to claim 4, wherein said electric power receiving device is mounted in a vehicle.

15. The wireless electric power feeding equipment according to claim 5, wherein said electric power receiving device is mounted in a vehicle.