Power transmission apparatus and wireless power transmission system

• US 9,866,033 B2
• Filed: 10/23/2014
• Issued: 01/09/2018
• Est. Priority Date: 10/28/2013
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Yamamoto, Atsushi, Kanno, Hiroshi
• Primary Examiner(s): Kessie, Daniel
• Application Number:
  US14/522,240
• Publication Number:
  US 20150115728A1
• Time in Patent Office: 1,174 Days
• 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 50/10 using inductive coupling
• 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 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 7/0042 characterised by the mechanical construction

Abstract

A power transmission apparatus includes the following elements. A position detection coil detects a signal from a power reception coil of a power reception apparatus installed on an installation surface. A position detection circuit determines from the detected signal that the power reception apparatus is installed on the installation surface. A reception circuit receives a wireless signal transmitted from the power reception apparatus via the position detection coil. A switch circuit switches electrical connection of the position detection coil between the position detection circuit and the reception circuit. A power transmission control circuit switches electrical connection of the position detection coil from the position detection circuit to the reception circuit if it is determined that a voltage or a current of the detected signal has been smaller than a reference value for a predetermined period, and causes the reception circuit to receive the wireless signal via the position detection coil.

Claims

1. A power transmission apparatus for transmitting power to one or more power reception apparatuses each including a power reception coil in a non-contact manner, comprising:

a power transmission coil that is disposed within the power transmission apparatus opposite an installation surface of the power transmission apparatus, the one or more power reception apparatuses are installed on the installation surface, the power transmission apparatus being capable of being electromagnetically coupled with the power reception coil;

a plurality of position detection coils that are disposed side by side between the installation surface and the power transmission coil, and that detect each signal from each the power reception coil included in the one or more power reception apparatuses installed on the installation surface;

a position detection circuit that receives, from each of the plurality of position detection coils, voltages or currents of the signals detected by each of the plurality of position detection coils;

a power transmission control circuit that determines a position of the one or more power reception apparatuses installed on the installation surface by comparing the voltages or the currents of the signals;

a reception circuit that demodulates into a data signal a wireless signal transmitted from the one or more power reception apparatuses to the power transmission apparatus and that outputs the data signal to the power transmission control circuit; and

a switch circuit that switches between electrical connection of each of the plurality of position detection coils to the position detection circuit, and electrical connection of each of the plurality of position detection coils to the reception circuit, wherein, when the power transmission control circuit determines that the one or more power reception apparatuses are installed at the determined position of the one or more power reception apparatuses installed on the installation surface for a predetermined time, the power transmission control circuit switches the electrical connection of a position detection coil corresponding to the determined position of the one or more power reception apparatuses from the position detection circuit to the reception circuit, and causes the reception circuit to receive the wireless signal via the position detection coil.

2. The power transmission apparatus according to claim 1, wherein the power transmission control circuit determines the position of the one or more power reception apparatuses installed on the installation surface by comparing the intensities of the voltages or the currents of the signals or by comparing the impedances of the voltage or the current of the signals.

3. The power transmission apparatus according to claim 1, further comprising:

a direct current power supply source; and

a power transmission circuit that converts a direct current voltage supplied from the direct current power supply source into an alternating current voltage,

wherein the power transmission coil is connected to the power transmission circuit.

4. The power transmission apparatus according to claim 1, further comprising:

a transmission circuit that transmits a different wireless signal, which is different from the wireless signal transmitted from the one or more power reception apparatuses, to the one or more power reception apparatuses,

wherein the transmission circuit is connected to a position detection coil and transmits the different wireless signal to the power reception apparatus via the position detection coil.

5. The power transmission apparatus according to claim 1, wherein a frequency of the wireless signal transmitted from the one or more power reception apparatuses to the power transmission apparatus is set to be different from a frequency used for transmitting power from the power transmission apparatus in a non-contact manner.

6. The power transmission apparatus according to claim 1, wherein:

the one or more power reception apparatuses are a plurality of power reception apparatuses;

the plurality of power reception apparatuses are installed on the installation surface; and

a plurality of wireless signals transmitted from the plurality of power reception apparatuses and received by the power transmission apparatus have different frequencies from each other.

7. A wireless power transmission system comprising:

the power transmission apparatus according to claim 1; and

the one or more power reception apparatuses.