Relay device of wireless power transmission system

• US 9,893,534 B2
• Filed: 12/03/2013
• Issued: 02/13/2018
• Est. Priority Date: 12/04/2012
• Status: Active Grant

• Current Assignee: Advantest Corporation
• Original Assignee: Advantest Corporation
• Inventors: Endo, Yuki, Furukawa, Yasuo
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Evans, James
• Application Number:
  US14/095,434
• Publication Number:
  US 20140152119A1
• Time in Patent Office: 1,533 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

Abstract

A relay antenna includes a power relay coil. An automatic tuning assist circuit is coupled with the relay antenna. The automatic tuning assist circuit has first and second terminals coupled with the relay antenna. Multiple switches are arranged together with N (N represents an integer) auxiliary capacitors between the first terminal and the second terminal. A controller is configured to switch on and off each of the multiple switches in synchronization with an electric power signal transmitted from a wireless power supply apparatus.

Claims

1. A relay device employed in a resonance wireless power transmission system, wherein the resonance wireless power transmission system includes a wireless power supply apparatus having a transmission antenna structured to transmit a power signal and a wireless power receiving apparatus having a receiving antenna structured to receive the power signal, and a degree of coupling between the transmission antenna and the receiving antenna changes with time, and wherein the relay device is separately positioned from the wireless power supply apparatus and the wireless power receiving apparatus respectively, and the relay device functions to relay power between the transmitting antenna and the receiving antenna,

the relay device comprising:

a relay antenna comprising a power relay coil; and

an automatic tuning assist circuit coupled with the relay antenna,

wherein the automatic tuning assist circuit comprises;

a first terminal and a second terminal coupled with the relay antenna;

N (N represents an integer) auxiliary capacitors;

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

a controller configured to switch on and off the plurality of switches in synchronization with an electric power signal transmitted from a wireless power supply apparatus, wherein the plurality of switches includes a first switch and a second switch,

and wherein the N auxiliary capacitors include a first auxiliary capacitor,

and wherein the first switch and the first auxiliary capacitor are arranged in series between the first terminal and the second terminal,

and wherein the second switch is arranged between the first terminal and the second terminal, in parallel with the first switch and the first auxiliary capacitor.

2. The relay device according to claim 1, wherein the controller is configured to switch on and off the plurality of switches with the same frequency as that of the electric power signal transmitted from the wireless power supply apparatus, or otherwise with a frequency obtained by multiplying or otherwise dividing the frequency of the electric power signal by an odd number.

3. The relay device according to claim 1, wherein the N auxiliary capacitors further include a second auxiliary capacitor,

and wherein the second auxiliary capacitor is arranged between the first terminal and the second terminal, in series with the second switch.

4. The relay device according to claim 1, wherein the first switch and the second switch are each configured as a uni-directional switch having an inversely conducting element,

and wherein the controller is configured to switch on and off the first switch and the second switch with a phase such that no current flows through their inversely conducting elements.

5. The relay device according to claim 3, wherein the first switch and the second switch are each configured as a bi-directional switch.

6. The relay device according to claim 1, wherein the relay antenna is coupled in series with the relay antenna via a transformer.

7. The relay device according to claim 1, wherein the relay antenna further comprises a resonance capacitor arranged in series with the power relay coil.

8. A relay device employed in a resonance wireless power transmission system, wherein the resonance wireless power transmission system includes a wireless power supply apparatus having a transmission antenna structured to transmit a power signal and a wireless power receiving apparatus having a receiving antenna structured to receive the power signal, and a degree of coupling between the transmission antenna and the receiving antenna changes with time,

and wherein the relay device is separately positioned from the wireless power supply apparatus and the wireless power receiving apparatus respectively, and the relay device functions to relay power between the transmitting antenna and the receiving antenna,

the relay device comprising:

a relay antenna comprising a power relay coil; and

an automatic tuning assist circuit coupled with the relay antenna;

wherein the automatic tuning assist circuit comprises;

a first terminal and a second terminal coupled with the relay antenna;

N (N represents an integer) auxiliary capacitors;

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

a controller configured to switch on and off the plurality of switches in synchronization with an electric power signal transmitted from a wireless power supply apparatus,

wherein the plurality of switches includes a first switch, a second switch, a third switch, and a fourth switch,

and wherein the N auxiliary capacitors include a first auxiliary capacitor,

and wherein the first switch and the second switch are arranged in series between the first terminal and the second terminal,

and wherein the third switch and the fourth switch are sequentially arranged in series between the first terminal and the second terminal, forming a path in parallel with the first switch and the second switch,

and wherein the first auxiliary capacitor is arranged between a connection node that connects the first switch and the second switch and a connection node that connects the third switch and the fourth switch.

9. The relay device according to claim 8, wherein the first switch through the fourth switch are each configured as a uni-directional switch having an inversely conducting element,

and wherein the controller is configured to switch on and off the first switch through the fourth switch with a phase such that no current flows through their inversely conducting elements.

10. The relay device according to claim 8, wherein the first switch through the fourth switch are each configured as a bi-directional switch.