NON-CONTACT POWER FEEDER AND NON-CONTACT POWER FEEDING METHOD

• US 20140300315A1
• Filed: 04/01/2014
• Published: 10/09/2014
• Est. Priority Date: 04/03/2013
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Funai Electric Co., Ltd.
• Inventors: Wakabayashi, Naoyuki
• Granted Patent: US 9,438,068 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A non-contact power feeder includes a plurality of power transmission coils disposed along a disposition surface, wherein a power receiving device that houses a power reception coil is disposed on the disposition surface, and a controller that determines a first traveling wave power, from among a plurality of traveling wave powers, that feeds the power transmission coil corresponding to the power receiving device based on a state of change of at least one of: actual transmitted power, from the plurality of traveling wave powers, transmitted from the plurality of power transmission coils to the power reception coil when power transmitted to the plurality of power transmission coils is changed, and reactive power, from the plurality of traveling wave powers, not transmitted from the power transmission coil to the power reception coil when the power transmitted to the plurality of power transmission coils is changed.

Claims

1. A non-contact power feeder, comprising:

a plurality of power transmission coils disposed along a disposition surface, wherein a power receiving device that houses a power reception coil is disposed on the disposition surface; and

a controller that determines a first traveling wave power, from among a plurality of traveling wave powers, that feeds the power transmission coil corresponding to the power receiving device based on a state of change of at least one of;

actual transmitted power, from the plurality of traveling wave powers, transmitted from the plurality of power transmission coils to the power reception coil when power transmitted to the plurality of power transmission coils is changed, and

reactive power, from the plurality of traveling wave powers, not transmitted from the power transmission coil to the power reception coil when the power transmitted to the plurality of power transmission coils is changed.

2. The non-contact power feeder according to claim 1, wherein the controller determines the first traveling wave power based further on a change amount of at least one of the actual transmitted power and the reactive power.

3. The non-contact power feeder according to claim 2, wherein the controller obtains an inflection point between at least one of the actual transmitted power and the reactive power and the traveling wave power, and determines the traveling wave power at a time when the inflection point is obtained as the first traveling wave power.

4. The non-contact power feeder according to claim 1, wherein the controller, by driving the plurality of power transmission coils and measuring the actual transmitted power, detects one or more of the power transmission coils for which the actual transmitted power is maximum as the power transmission coil that feeds the actual transmitted power to the disposed power receiving device.

5. The non-contact power feeder according to claim 4, wherein the controller sequentially adds and drives the power transmission coils around the detected power transmission coil for which the actual transmitted power is the maximum value, detects the power transmission coil for which the actual transmitted power increases, and determines a power transmission coil cluster as the power transmission coil that feeds the actual transmitted power to the disposed power receiving device, wherein the power transmission coil cluster is a combination of one or more sets of power transmission coils used in power feeding.

6. The non-contact power feeder according to claim 1, wherein

a plurality of power receiving devices is disposed on the disposition surface, and

the controller determines a second traveling wave power that feeds the power transmission coil corresponding to each of the power receiving devices based on a ratio of the first traveling wave power corresponding to the each power receiving device instead of the first traveling wave power when a sum of the first traveling wave power corresponding to the each power receiving device exceeds a power feeding capacity of the non-contact power feeder.

7. The non-contact power feeder according to claim 1, further comprising:

a plurality of pressure sensors disposed at intervals along the disposition surface that detects a position where the power receiving device is disposed on the disposition surface, wherein

the actual transmitted power of only the power transmission coil near a position where the plurality of pressure sensors detects disposition of the power receiving device is measured.

8. The non-contact power feeder according to claim 1, further comprising:

a directional couple, wherein

the controller calculates the actual transmitted power by reducing a reflected wave power from the traveling wave power measured by the directional coupler.

9. The non-contact power feeder according to claim 1, wherein

a plurality of power receiving devices is disposed on the disposition surface, wherein the non-contact power feeder further comprises:

a display that displays a charging state and a size of the actual transmitted power corresponding to each of the plurality of power receiving devices during charging.

10. The non-contact power feeder according to claim 1, further comprising:

a plurality of lamps provided on the plurality of power transmission coils, wherein

one or more of the lamps near the power transmission coil light up during charging.

11. The non-contact feeder according to claim 1, wherein the controller continuously or at predetermined times measures the actual transmitted power fed to the power reception coil during power feeding and stops charging the power receiving device by stopping power feeding when a drop in the actual transmitted power is detected.

12. A non-contact power feeding method for a non-contact feeder comprising a plurality of power transmission coils disposed along a disposition surface, a power receiving device that houses a power reception coil being disposed on the disposition surface, the method comprising:

determining a first traveling wave power, from among a plurality of traveling wave powers, that feeds a power transmission coil corresponding to a power receiving device based on a state of change of at least one of;

actual transmitted power, from the plurality of traveling wave powers, transmitted from the plurality of power transmission coils to the power reception coil when power transmitted to the plurality of power transmission coils is changed, and

reactive power, from the plurality of traveling wave powers, not transmitted from the power transmission coil to the power reception coil when the power transmitted to the plurality of power transmission coils is changed.

13. The non-contact power feeding method according to claim 12, further comprising determining the first traveling wave power based further on a change amount of at least one of the actual transmitted power and the reactive power.

14. The non-contact power feeding method according to claim 13, further comprising obtaining an inflection point between at least one of the actual transmitted power and the reactive power and the traveling wave power, and determining the traveling wave power at a time when the inflection point is obtained as the first traveling wave power.

15. The non-contact power feeding method according to claim 12, further comprising:

driving the plurality of power transmission coils and measuring the actual transmitted power; and

detecting one or more of the power transmission coils for which the actual transmitted power is maximum as the power transmission coil that feeds the actual transmitted power to the disposed power receiving device.

16. The non-contact power feeding method according to claim 15, further comprising:

sequentially adding and driving the power transmission coils around the detected power transmission coil for which the actual transmitted power is the maximum value;

detecting the power transmission coil for which the actual transmitted power increases; and

determining a power transmission coil cluster as the power transmission coil that feeds the actual transmitted power to the disposed power receiving device, wherein the power transmission coil cluster is a combination of one or more sets of power transmission coils used in power feeding.

17. The non-contact power feeding method according to claim 12, wherein a plurality of power receiving devices is disposed on the disposition surface and the method further comprises:

determining a second traveling wave power that feeds the power transmission coil corresponding to each of the power receiving devices based on a ratio of the first traveling wave power corresponding to the each power receiving device instead of the first traveling wave power when a sum of the first traveling wave power corresponding to the each power receiving device exceeds a power feeding capacity of the non-contact power feeder.

18. The non-contact power feeding method according to claim 12, further comprising:

calculating the actual transmitted power by reducing a reflected wave power from the traveling wave power measured by a directional coupler.

19. The non-contact power feeding method according to claim 12, further comprising continuously or at predetermined times measuring the actual transmitted power fed to the power reception coil during power feeding and stopping charging the power receiving device by stopping power feeding when a drop in the actual transmitted power is detected.