Apparatus and method for wireless power transfer

• US 10,566,133 B2
• Filed: 01/14/2011
• Issued: 02/18/2020
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: City University of Hong Kong
• Original Assignee: City University of Hong Kong
• Inventors: Hui, Ron Shu Yuen, Zhong, Wenxing
• Primary Examiner(s): Gannon, Levi
• Application Number:
  US13/979,532
• Publication Number:
  US 20140028112A1
• Time in Patent Office: 3,322 Days
• Field of Search: 307104
• 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 50/005 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 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

Abstract

The present invention provides an apparatus for wireless power transfer including three or more coils, each coil defining a respective coil plane, and the coils being arranged in one or more power flow paths whereby each coil can be magnetically coupled to one or more of the other coils thereby to wirelessly transfer power along the one or more power flow paths. The present invention also provides a method for wirelessly transferring power, the method including: providing three or more coils, each coil defining a respective coil plane; and arranging the coils in one or more power flow paths whereby each coil can be magnetically coupled to one or more of the other coils thereby to wirelessly transfer power along the one or more power flow paths.

Claims

1. An apparatus for wireless power transfer, comprising:

a source coil resonator directly connected to an AC power source;

a load coil resonator directly connected to a load; and

three or more intermediate coil resonators, each not directly connected to a power source and not directly connected to a load, arranged between the source coil resonator and the load coil resonator to guide power flow therebetween;

each of the source coil resonator, the load coil resonator, and the intermediate coil resonators defining a respective coil plane;

the intermediate coil resonators being arranged so as to form two curved power flow paths from the source coil resonator to the load coil resonator;

the source coil resonator, the load coil resonator, and the intermediate coil resonators being magnetically coupled with each other only by magnetic resonance to wirelessly transfer power along the power flow path;

wherein a ratio of a distance between any two of the coil planes to half the maximum dimension of any of said two coil planes is less than 3 such that magnetic coupling among the source coil resonator, the load coil resonator, and the intermediate coil resonators is non-radiative; and

wherein the two curved power flow paths, when combined, are in a circular form.

2. The apparatus according to claim 1 wherein one or both of a resonant frequency and an impedance of the intermediate coil resonators is variable for affecting the power flow.

3. The apparatus according to claim 2 wherein the intermediate coil resonators each has one or both of a capacitance and an inductance, and the resonant frequency of one or more of the intermediate coil resonators can be varied by varying one or both of the capacitance and the inductance.

4. The apparatus according to claim 1 wherein a distance between one pair of the coil planes is not equal to a distance between another pair of the coil planes.

5. The apparatus according to claim 1 wherein the source coil resonator, the load coil resonator, and the intermediate coil resonators have an operating frequency of less than 100 MHz.

6. The apparatus according to claim 1 wherein the source coil resonator, the load coil resonator, and the intermediate coil resonators have an operating frequency of less than 10 MHz.

7. The apparatus according to claim 1 wherein the source coil resonator, the load coil resonator, and the intermediate coil resonators have an operating frequency of less than 5 MHz.

8. The apparatus according to claim 1 wherein the source coil resonator, the load coil resonator, and the intermediate coil resonators have an operating frequency of less than 1 MHz.

9. The apparatus according to claim 1 wherein the source coil resonator, the load coil resonator, and the intermediate coil resonators have an operating frequency of greater than 10 kHz.

10. The apparatus according to claim 1 wherein the intermediate coil resonators are made from superconductive material.