WIRELESS POWER TRANSMISSION SYSTEM

• US 20150333539A1
• Filed: 07/29/2015
• Published: 11/19/2015
• Est. Priority Date: 01/31/2013
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: KUSUNOKI, Masahiro, MASUDA, Mitsuru
• Granted Patent: US 10,097,039 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

[OBJECT] There is provided a wireless power transmission system capable of transmitting power efficiently even when it is rotated.

[ORGANIZATION] A power transmission device has a first and a second electrode (a center electrode 311 and an annular electrode 312) each having a rotationally symmetrical shape with respect to a common center axis, a first and a second connection line (connection lines 315, 316), and a first inductor to (inductor 313, 314). A power reception device has a third and a fourth electrode (center electrode 321 and annular electrode 322) each having a rotationally symmetrical shape with respect to a common center axis, a third and a fourth connection line (connection lines 325, 326), and a second inductor. The electrodes of the power transmission device and the power reception device are disposed to oppose each other across a distance of λ/2π or less as a near field, and a resonance frequency of a coupler constituted of the first and the second electrode and the first inductor and a resonance frequency of a coupler constituted of the third and the fourth electrode and the second inductor (inductor 323, 324) are set to be substantially equal.

Claims

1. A wireless power transmission system transmitting alternating-current power from a power transmission device to a power reception device, wherein

the power transmission device comprises:

a first and a second electrode which are disposed across a predetermined distance, in which a total width including the predetermined distance is λ

/2π

or less as a near field, the first and the second electrode each having a rotationally symmetrical shape with respect to a common center axis;

a first and a second connection line electrically connecting the first and the second electrode and two output terminals of an alternating-current power generating unit, respectively; and

a first inductor residing between the first and the second electrode and at least one of the two output terminals of the alternating current power generating unit, and

the power reception device comprises;

a third and a fourth electrode which are disposed across a predetermined distance, in which a total width including the predetermined distance is λ

/2π

or less as a near field, the third and the fourth electrode each having a rotationally symmetrical shape with respect to a common center axis;

a third and a fourth connection line electrically connecting the third and the fourth electrode and two input terminals of a load, respectively; and

a second inductor residing between the third and the fourth electrode and at least one of the two input terminals of the load, wherein

the electrodes of the power transmission device and the power reception device are disposed to oppose each other across a distance of λ

/2π

or less as a near field, and

a resonance frequency of a coupler constituted of the first and the second electrode and the first inductor and a resonance frequency of a coupler constituted of the third and the fourth electrode and the second inductor are set to be substantially equal.

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

the first electrode has a platy polygonal or circular shape, and the second electrode has a platy polygonal or circular annular shape disposed to surround the first electrode and is disposed on a same plane to have a center axis corresponding to that of the first electrode;

the third electrode has a platy polygonal or circular shape, and the fourth electrode has a platy polygonal or circular annular shape disposed to surround the third electrode and is disposed on a same plane to have a center axis corresponding to that of the third electrode; and

the first and the second electrode and the third and the fourth electrode are disposed to oppose each other across a distance of λ

/2π

or less as a near field.

3. The wireless power transmission system according to claim 2, wherein at least one of the first to the fourth electrode has a cutout in a radial direction.

4. The wireless power transmission system according to claim 1, wherein at least one of the first electrode and the third electrode has an annular shape.

5. The wireless power transmission system according to claim 1, wherein at least one of the first to the fourth electrode has a three-dimensional structure extending in an axial direction.

6. The wireless power transmission system according to claim 1, wherein

the first and the second electrode have a polygonal or circular cylindrical shape and the third and the fourth electrode have a polygonal or circular cylindrical shape disposed to surround the first and the second electrode, respectively, and are disposed to have a center axis corresponding to that of the first and the second electrode;

and

the first and the third electrode and the second and the fourth electrode are disposed to oppose each other across a distance of λ

/2π

or less as a near field.