Wireless power transmission system and resonance frequency adjustment unit for wireless power transmission system

Patent metadata

Field	Value
Publication number	US-12218517-B2
Application number	US-202318363412-A
Country	US
Kind code	B2
Filing date	Aug 1, 2023
Priority date	Feb 2, 2021
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

A wireless power transmission system includes a structure entirely surrounded by an electromagnetic wave shielding member having appropriate electrical conductivity and appropriate frequency selectivity; at least one power receiving unit; at least one power transmission unit; and at least one resonance frequency adjuster. The resonance frequency adjuster includes at least one conductive protrusion having an open end and a transmission line connected to another end of the conductive protrusion at one end of the transmission line, wherein the open end of the conductive protrusion is arranged inside the structure, and the transmission line is electrically connected to the electromagnetic wave shielding member defining a wall surface of the structure at another end not connected to the conductive protrusion.

First claim

What is claimed is:

1. A wireless power transmission system comprising:
a structure entirely surrounded by an electromagnetic wave shielding member having appropriate electrical conductivity and appropriate frequency selectivity;
at least one power receiving unit;
at least one power transmission unit; and
at least one resonance frequency adjuster,
wherein the resonance frequency adjuster includes:
at least one conductive protrusion having an open end; and
a transmission line connected to another end of the conductive protrusion at one end of the transmission line,
wherein the open end of the conductive protrusion is inside the structure,
the transmission line is electrically connected to the electromagnetic wave shielding member defining a wall surface of the structure at another end not connected to the conductive protrusion,
the power transmission unit includes a power transmitter, a matching circuit, and a power supply,
the matching circuit is configured to adjust to match an impedance between the power transmission unit and the structure at a pre-set transmission frequency, and
the wireless power transmission system is configured to use a constant transmission frequency.

2. The wireless power transmission system according to claim 1 , wherein
the another end of the conductive protrusion and the transmission line are inside the structure.

3. The wireless power transmission system according to claim 2 , wherein
an inductor or a capacitor is attached to the transmission line.

4. The wireless power transmission system according to claim 2 , wherein
a variable inductor or a variable capacitor is attached to the transmission line.

5. The wireless power transmission system according to claim 2 , wherein
the open end of the conductive protrusion is at a position where a relative electric field strength is from 0.2 to 1, assuming that a maximum electric field strength in a space away from the power transmission unit by λ/20 or more within a space entirely surrounded by the electromagnetic wave shielding member is defined as 1, where λ is a wavelength of electromagnetic waves emitted from the power transmission unit.

6. The wireless power transmission system according to claim 2 , wherein
the resonance frequency adjuster is on a wall surface of the structure, the wall surface being perpendicular to an azimuth where an order of a resonance mode is zero when the resonance mode is a TE(0np) mode and n and p are integers.

7. The wireless power transmission system according to claim 1 , wherein
the another end of the conductive protrusion and the transmission line are outside the structure.

8. The wireless power transmission system according to claim 7 , wherein
an inductor or a capacitor is attached to the transmission line.

9. The wireless power transmission system according to claim 7 , wherein
a variable inductor or a variable capacitor is attached to the transmission line.

10. The wireless power transmission system according to claim 7 , wherein
the open end of the conductive protrusion is at a position where a relative electric field strength is from 0.2 to 1, assuming that a maximum electric field strength in a space away from the power transmission unit by λ/20 or more within a space entirely surrounded by the electromagnetic wave shielding member is defined as 1, where λ is a wavelength of electromagnetic waves emitted from the power transmission unit.

11. The wireless power transmission system according to claim 7 , wherein
the resonance frequency adjuster is on a wall surface of the structure, the wall surface being perpendicular to an azimuth where an order of a resonance mode is zero when the resonance mode is a TE(0np) mode and n and p are integers.

12. The wireless power transmission system according to claim 1 , wherein
an inductor or a capacitor is attached to the transmission line.

13. The wireless power transmission system according to claim 12 , wherein
the open end of the conductive protrusion is at a position where a relative electric field strength is from 0.2 to 1, assuming that a maximum electric field strength in a space away from the power transmission unit by λ/20 or more within a space entirely surrounded by the electromagnetic wave shielding member is defined as 1, where λ is a wavelength of electromagnetic waves emitted from the power transmission unit.

14. The wireless power transmission system according to claim 1 , wherein
a variable inductor or a variable capacitor is attached to the transmission line.

15. The wireless power transmission system according to claim 1 , wherein
the open end of the conductive protrusion is at a position where a relative electric field strength is from 0.2 to 1, assuming that a maximum electric field strength in a space away from the power transmission unit by λ/20 or more within a space entirely surrounded by the electromagnetic wave shielding member is defined as 1, where λ is a wavelength of electromagnetic waves emitted from the power transmission unit.

16. The wireless power transmission system according to claim 15 , wherein
the open end of the conductive protrusion is arranged at a position where the relative electric field strength is from 0.33 to 1.

17. The wireless power transmission system according to claim 1 , wherein
the resonance frequency adjuster is on a wall surface of the structure, the wall surface being perpendicular to an azimuth where an order of a resonance mode is zero when the resonance mode is a TE(0np) mode and n and p are integers.

18. A resonance frequency adjuster for a wireless power transmission system, the resonance frequency adjuster comprising:
at least one conductive protrusion having an open end; and
a transmission line connected to another end of the conductive protrusion at one end of the transmission line,
wherein the wireless power transmission system includes:
a structure entirely surrounded by an electromagnetic wave shielding member having appropriate electrical conductivity and appropriate frequency selectivity;
at least one power receiving unit; and
at least one power transmission unit,
wherein the open end of the conductive protrusion is inside the structure,
the transmission line is configured to electrically connect to the electromagnetic wave shielding member defining a wall surface of the structure at another end not connected to the conductive protrusion,
the power transmission unit includes a power transmitter, a matching circuit, and a power supply,
the matching circuit is configured to adjust to match an impedance between the power transmission unit and the structure at a pre-set transmission frequency, and
the wireless power transmission system is configured to use a constant transmission frequency.

19. The resonance frequency adjuster according to claim 18 , wherein
an inductor or a capacitor is attached to the transmission line.

20. The resonance frequency adjuster according to claim 18 , wherein
a variable inductor or a variable capacitor is attached to the transmission line.

Assignees

• Murata Manufacturing Co
• National Univ Corporation Toyohashi Univ Of Technology

Inventors

• Saeki Hiromasa
• Tamura Masaya
• Akai Suzuka

Classifications

• H02J50/005 Primary

  Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices · CPC title

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title

• H02J50/70

  involving the reduction of electric, magnetic or electromagnetic leakage fields · CPC title

• H02J50/12 Primary

  of the resonant type · CPC title

• H01Q15/14

  Reflecting surfaces; Equivalent structures {(electromagnetic shields H01Q1/526)} · CPC title