WIRELESS POWER TRANSMITTING APPARATUS AND WIRELESS POWER SUPPLY SYSTEM

• US 20150015087A1
• Filed: 09/30/2014
• Published: 01/15/2015
• Est. Priority Date: 04/02/2012
• Status: Active Grant

• Current Assignee: Advantest Corporation
• Original Assignee: Advantest Corporation
• Inventors: Endo, Yuki, Furukawa, Yasuo
• Granted Patent: US 9,882,550 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H03J 7/04 where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transmitting apparatus transmits an electric power signal comprising any one from among an electric field, a magnetic field, and an electromagnetic field to a wireless power receiving apparatus. A reflector coil is arranged at a distance from a radiation coil. A driving power supply supplies a driving current to the radiation coil. A first phase control circuit controls the phase of the current that flows through the reflector coil so as to stabilize, to a predetermined value, the phase difference between the current that flows through the reflector coil and the current that flows through the radiation coil.

Claims

1. A wireless power transmitting apparatus which transmits an electric power signal comprising any one from among an electric field, a magnetic field, and an electromagnetic field to a wireless power receiving apparatus, the wireless power transmitting apparatus comprising:

a radiation coil;

a reflector coil arranged at a distance from the radiation coil;

a driving power supply that supplies a driving current to the radiation coil; and

a first phase control circuit that controls the phase of a current that flows through the reflector coil so as to stabilize the phase difference between the current that flows through the reflector coil and a current that flows through the radiation coil.

2. The wireless power transmitting apparatus according to claim 1, wherein the first phase control circuit comprises an automatic tuning assist circuit coupled in series with the reflector coil,

and wherein the automatic tuning assist circuit comprises:

a first terminal;

a second terminal;

N (N represents an integer) auxiliary capacitors each having a first electrode and a second electrode;

a plurality of switches each of which is arranged between two terminals from among the first terminal, the second terminal, and terminals of the N auxiliary capacitors; and

a controller that switches on and off each one of the plurality of switches in synchronization with the current that flows through the radiation coil.

3. The wireless power transmitting apparatus according to claim 1, wherein the first phase control circuit comprises a current source that supplies an AC current having a predetermined phase to the reflector coil.

4. The wireless power transmitting apparatus according to claim 1, wherein the driving power supply comprises:

an automatic tuning assist circuit coupled in series with the radiation coil; and

a voltage source that applies an AC driving voltage across both terminals of a circuit that comprises the radiation coil and the automatic tuning assist circuit,

and wherein the automatic tuning assist circuit comprises;

a first terminal;

a second terminal;

N (N represents an integer) auxiliary capacitors each having a first electrode and a second electrode;

a plurality of switches each of which is arranged between two terminals from among the first terminal, the second terminal, and terminals of the N auxiliary capacitors; and

a controller that switches on and off each one of the plurality of switches in synchronization with the driving voltage with a predetermined phase difference with respect to the driving voltage.

5. The wireless power transmitting apparatus according to claim 1, wherein the driving power supply comprises a current source that supplies a driving current having a predetermined phase to the radiation coil.

6. The wireless power transmitting apparatus according to claim 1, further comprising:

a waveguide coil provided to the radiation coil at a distance from the radiation coil on a side opposite to the reflector coil; and

a second phase control circuit that controls the phase of a current that flows through the waveguide coil so as to stabilize the phase difference between the current that flows through the waveguide coil and a current that flows through the radiation coil.

7. The wireless power transmitting apparatus according to claim 6, wherein the second phase control circuit comprises an automatic tuning assist circuit coupled in series with the waveguide coil,

and wherein the automatic tuning assist circuit comprises:

a first terminal;

a second terminal;

N (N represents an integer) auxiliary capacitors each having a first electrode and a second electrode;

a plurality of switches each of which is arranged between two terminals from among the first terminal, the second terminal, and terminals of the N auxiliary capacitors; and

a controller that switches on and off each one of the plurality of switches in synchronization with the current that flows through the radiation coil.

8. The wireless power transmitting apparatus according to claim 6, wherein the second phase control circuit comprises a current source that supplies an AC current having a predetermined phase to the waveguide coil.

9. The wireless power transmitting apparatus according to claim 1, further comprising:

at least one space compression coil arranged between the radiation coil and the reflector coil; and

at least one third phase control circuit provided for each of the at least one space compression coils, wherein each third phase control circuit controls the phase of a current that flows through the corresponding space compression coil so as to stabilize the phase difference between the current that flows through the space compression coil and a current that flows through the radiation coil.

10. The wireless power transmitting apparatus according to claim 9, wherein the third phase control circuit comprises an automatic tuning assist circuit coupled in series with the corresponding space compression coil,

and wherein the automatic tuning assist circuit comprises:

a first terminal;

a second terminal;

N (N represents an integer) auxiliary capacitors each having a first electrode and a second electrode;

a plurality of switches each of which is arranged between two terminals from among the first terminal, the second terminal, and terminals of the N auxiliary capacitors; and

a controller that switches on and off each one of the plurality of switches in synchronization with the current that flows through the radiation coil.

11. The wireless power transmitting apparatus according to claim 9, wherein the third phase control circuit comprises a current source that supplies an AC current having a predetermined phase to the corresponding space compression coil.

12. The wireless power transmitting apparatus according to claim 1, further comprising a magnetic plate interposed between the radiation coil and the reflector coil.

13. A wireless power supply system comprising:

the wireless power transmitting apparatus according to claim 1; and

a wireless power receiving apparatus that receives an electric power signal from the wireless power transmitting apparatus.