Wireless power transmission method and apparatus for improving spectrum efficiency and space efficiency based on impedance matching and relay resonance

• US 10,038,340 B2
• Filed: 09/11/2014
• Issued: 07/31/2018
• Est. Priority Date: 10/21/2013
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Cho, In Kui, Kim, Seong Min, Moon, Jung Ick, Yun, Je Hoon
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Barnett, Joel
• Application Number:
  US14/483,382
• Publication Number:
  US 20150108850A1
• Time in Patent Office: 1,419 Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

Provided is a wireless power transmission method and apparatus for improving spectrum efficiency and space efficiency based on impedance matching and relay resonance, the method including detecting an input impedance at a resonant frequency, matching a transmitting port impedance to a real number value of the detected input impedance, and transmitting power to a receiving resonator smaller than a transmitting resonator using the relay resonator.

Claims

1. A wireless power transmitting apparatus, the apparatus comprising:

an input impedance detector to detect an input impedance of a transmitting resonator connected to the wireless power transmitting apparatus at a resonant frequency;

a control signal output unit to output a control signal to control a transmitting port impedance based on the input impedance;

a transmitting port impedance converter to convert the transmitting port impedance to match a real number value of the input impedance at the resonant frequency based on the control signal without a matching of a receiving port impedance; and

a power transmitter to transmit power to a wireless power receiving apparatus through the transmitting resonator at the resonant frequency based on the converted transmitting port impedance,

wherein the input impedance is determined based on a distance between the transmitting resonator and a receiving resonator connected to the wireless power receiving apparatus,

wherein the transmitting port impedance is converted by adjusting a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.

2. The apparatus of claim 1, wherein the control signal output unit outputs the control signal further based on an amount of power consumed in the wireless power receiving apparatus.

3. The apparatus of claim 1, wherein the transmitting port impedance is converted by adjusting a coupling coefficient k₁₂ determined based on a distance between the feeding coil and the transmitting resonator.

4. The apparatus of claim 3, wherein the coupling coefficient k₁₂ is determined to be larger as the distance between the feeding coil and the transmitting resonator decreases.

5. The apparatus of claim 1, wherein the input impedance is determined to be smaller as the distance between the transmitting resonator and the receiving resonator becomes closer.

6. A wireless power receiving apparatus, the apparatus comprising:

a power receiver to receive power from a transmitting resonator connected to a wireless power transmitting apparatus at a resonant frequency; and

a load unit consuming the received power,

wherein the wireless power transmitting apparatus converts a transmitting port impedance to match a real number value of an input impedance of the transmitting resonator detected at the resonant frequency without a matching of a receiving port impedance and transmits power through the transmitting resonator,

wherein the input impedance is determined based on a distance between the transmitting resonator and a receiving resonator connected to the wireless power receiving apparatus, and

wherein the transmitting port impedance is converted by adjusting a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.

7. The apparatus of claim 6, wherein the wireless power transmitting apparatus converts the transmitting port impedance by controlling a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.

8. A wireless power transfer apparatus, the apparatus comprising:

a transmitting resonator to transmit power generated from a wireless power transmitting apparatus to a receiving resonator at a resonant frequency; and

the receiving resonator to receive the power from the transmitting resonator using a relay resonator,

wherein a size of the receiving resonator is smaller than a size of the transmitting resonator,

wherein the relay resonator controls a receiving efficiency of the receiving resonator by adjusting a distance from the receiving resonator,

wherein the wireless power transmitting apparatus converts a transmitting port impedance to match a real number value of an input impedance of the transmitting resonator detected at the resonant frequency without a matching of a receiving port impedance and generates power,

wherein the input impedance is determined based on a distance between the transmitting resonator and a receiving resonator connected to a wireless power receiving apparatus, and

wherein the transmitting port impedance is converted by adjusting a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.

9. The apparatus of claim 8, wherein the wireless power transmitting apparatus converts the transmitting port impedance by controlling a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.

10. The apparatus of claim 8, wherein a size of the relay resonator is identical to a size of the transmitting resonator.

11. A wireless power transmitting method, the method comprising:

detecting an input impedance of a transmitting resonator connected to a wireless power transmitting apparatus at a resonant frequency;

outputting a control signal to adjust a transmitting port impedance based on the input impedance;

converting the transmitting port impedance to match a real number value of the input impedance at the resonant frequency based on the control signal without a matching of a receiving port impedance; and

transmitting power to a wireless power receiving apparatus through the transmitting resonator at the resonant frequency based on the converted transmitting port impedance,

wherein the input impedance is determined based on a distance between the transmitting resonator and a receiving resonator connected to the wireless power receiving apparatus, and

wherein the transmitting port impedance is converted by adjusting a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.

12. The method of claim 11, wherein the converting is performed by controlling a distance between the transmitting resonator and a feeding coil used to provide power to the transmitting resonator.