Wireless power feeder and wireless power receiver

• US 8,800,738 B2
• Filed: 06/28/2011
• Issued: 08/12/2014
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Urano, Takashi
• Primary Examiner(s): LE, MARK T
• Application Number:
  US13/170,782
• Publication Number:
  US 20120161530A1
• Time in Patent Office: 1,141 Days
• Field of Search: 191/10, 191/6, 191/14, 191/15, 307/104, 320/108
• US Class Current: 191/10
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• 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 50/70 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: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• 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
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

A wireless power feeder 116 feeds power from a feeding coil L2 in the ground to a receiving coil L3 incorporated in an EV by wireless using a magnetic field resonance phenomenon between the feeding coil L2 and receiving coil L3. A plurality of feeding coils L2a to L2d are buried in the ground. Receivers 112a to 112d are buried in corresponding respectively with the feeding coils L2a to L2d. The plurality of receivers 112 each receive a position signal transmitted from a transmitter 110 of the EV. A feeding coil circuit 120 supplies AC power to the feeding coil L2 corresponding to the receiver 112 that has received the position signal to allow the feeding coil L2 to feed power to the receiving coil L3 by wireless.

Claims

1. A wireless power feeder that feeds power from a feeding coil to a receiving coil by wireless using a magnetic field resonance phenomenon between the feeding coil and receiving coil, said feeder comprising:

a capacitor;

a plurality of the feeding coils;

a plurality of receivers that are provided respectively in correspondence with the plurality of feeding coils and each receives a position signal from a receiving body having the receiving coil;

a power transmission control circuit that supplies AC power at a drive frequency to the feeding coil corresponding to the receiver that has received the position signal to allow the feeding coil to feed AC power to the receiving coil; and

a selection circuit for selecting a receiver from the plurality of receivers, the selection circuit including a plurality of photodiodes,

wherein an input of each of the plurality of photodiodes is connected to a corresponding receiver of the plurality of receivers,

wherein an output of each of the plurality of photodiodes is connected to a common line,

wherein the power transmission control circuit supplies the AC power to the feeding coil corresponding to the selected receiver,

wherein any one of the feeding coils is selectively connected to the capacitor, the selected feeding coil and the capacitor resonate at a resonance frequency, and

the power transmission control circuit adjusts the drive frequency to the resonance frequency.

2. The wireless power feeder according to claim 1, further comprising a phase detection circuit that detects the phase difference between the voltage phase and current phase of the AC power.

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

the power transmission control circuit adjusts the drive frequency such that the detected phase difference is reduced.

4. A wireless power receiver that receives AC power fed from the wireless power feeder as claimed in claim 1 by wireless at a receiving coil, said receiver comprising:

the receiving coil;

a transmitter that transmits a position signal representing the position of the wireless power receiver; and

a loading coil that is magnetically coupled to the receiving coil to receive the AC power that the receiving coil has received from the feeding coil.

5. The wireless power receiver that receives AC power fed from the wireless power feeder according to claim 4, further comprising a storage battery that is connected to the loading coil and is charged by the received AC power.

6. The wireless power receiver that receives AC power fed from the wireless power feeder according to claim 4, wherein

the wireless power receiver is constructed as a moving body that uses the AC power received by the loading coil as a power source.

7. The wireless power feeder according to claim 1, wherein the selection circuit is configured so as to exclusively select one of the receivers when two or more receivers have received the position signal.

8. The wireless power feeder according to claim 7, wherein the plurality of photodiodes have different input voltages relative to each other.

9. A wireless power feeder that feeds power from a feeding coil to a receiving coil by wireless using a magnetic field resonance phenomenon between the feeding coil and receiving coil, said feeder comprising:

a plurality of the feeding coils;

a plurality of receivers that are provided respectively in correspondence with the plurality of feeding coils and each receives a position signal from a receiving body having the receiving coil;

a power transmission control circuit that supplies AC power at a drive frequency to the feeding coil corresponding to the receiver that has received the position signal to allow the feeding coil to feed AC power to the receiving coil; and

a selection circuit for selecting a receiver from the plurality of receivers, the selection circuit including a plurality of photodiodes,

wherein an input of each of the plurality of photodiodes is connected to a corresponding receiver of the plurality of receivers,

wherein an output of each of the plurality of photodiodes is connected to a common line,

wherein the power transmission control circuit supplies the AC power to the feeding coil corresponding to the selected receiver, and

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.

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

the power transmission control circuit makes the feeding coil that does not substantially resonate with circuit elements on the power feeding side feed the AC power to the receiving coil.

11. The wireless power feeder according to claim 9,

wherein no capacitor is connected in series or in parallel to the feeding coil.

12. The wireless power feeder according to claim 9, wherein the selection circuit is configured so as to exclusively select one of the receivers when two or more receivers have received the position signal.

13. The wireless power feeder according to claim 12, wherein the plurality of photodiodes have different input voltages relative to each other.