RELAY DEVICE OF WIRELESS POWER TRANSMISSION SYSTEM

• US 20140152119A1
• Filed: 12/03/2013
• Published: 06/05/2014
• Est. Priority Date: 12/04/2012
• Status: Active Grant

• Current Assignee: Advantest Corporation
• Original Assignee: Advantest Corporation
• Inventors: ENDO, Yuki, Furukawa, Yasuo
• Granted Patent: US 9,893,534 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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, 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.

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 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.

4. The relay device according to claim 3, 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.

5. The relay device according to claim 3, 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.

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

7. The relay device according to claim 1, 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.

8. The relay device according to claim 7, 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.

9. The relay device according to claim 7, wherein the first switch through the fourth switch are each configured as a bi-directional switch.

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

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

10. A relay device employed in a resonance wireless power transmission system, 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;

N (N represents an integer) auxiliary capacitors;

a plurality of switches arranged in order to charge and discharge the N auxiliary capacitors using a current that flows through the relay antenna; and

a controller configured to perform switching of the plurality of switches so as to generate capacitor voltages across the N auxiliary capacitors respectively, and to apply, to the relay antenna, a correction voltage that corresponds to the capacitor voltages across the N auxiliary capacitors.

13. A relay device employed in a resonance wireless power transmission system, comprising:

a relay antenna comprising a power relay coil; and

an automatic tuning assist circuit coupled with the relay antenna, and configured to inject a correction current into the relay antenna or otherwise to draw a correction current from 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 coils; and

a plurality of switches arranged between two terminals from among the first terminal, the second terminal, and the terminals of the N auxiliary coils; 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.

14. The relay device according to claim 13, 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.

15. The relay device according to claim 13, wherein the plurality of switches include a first switch and a second switch,

and wherein the N auxiliary coils include a first auxiliary coil,

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

and wherein the second switch is arranged in parallel with the first auxiliary coil.

16. The relay device according to claim 15, wherein the first switch and the second switch each comprise:

a uni-directional switch having a inversely conducting element; and

a rectifier diode arranged in series with the uni-directional switch, in a direction that is the reverse of the direction of the inversely conducting element of the uni-directional switch.

17. The relay device according to claim 15, wherein the first switch and the second switch are each configured as a bi-directional switch.

18. The relay device according to claim 13, wherein the plurality of switches includes a first switch, a second switch, a third switch, and a fourth switch,

and wherein the N auxiliary coils include a first auxiliary coil and a second auxiliary coil,

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

and wherein the second switch is arranged in parallel with the first auxiliary coil,

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

and wherein the fourth switch is arranged in parallel with the second auxiliary coil.

19. The relay device according to claim 13, wherein the plurality of switches includes a first switch, a second switch, a third switch, and a fourth switch,

and wherein the N auxiliary coils include a first auxiliary coil,

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 arranged in series between the first terminal and the second terminal, in parallel with the first switch and the second switch,

and wherein the first auxiliary coil 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.

20. The relay device according to claim 19, wherein the first switch through the fourth switch each comprise:

a uni-directional switch having an inversely conducting element; and

a rectifier diode arranged in series with the uni-directional switch, in a direction that is the reverse of the direction of the inversely conducting element of the uni-directional switch.

21. The relay device according to claim 19, wherein the first switch through the fourth switch are each configured as a bi-directional switch.

24. The relay device according to claim 13, wherein the automatic tuning assist circuit is directly coupled with the relay antenna.

25. The relay device according to claim 13, wherein the automatic tuning assist circuit is coupled with the relay antenna via a transformer.

26. The relay device according to claim 13, wherein the first terminal is connected to one end of the power relay coil, and the second terminal is connected to the other terminal of the power relay coil.

27. The relay device according to claim 13, wherein the relay antenna further comprises a resonance capacitor arranged in series with the power relay coil,

and wherein the first terminal is connected to one end of the resonance capacitor, and the second terminal is connected to the other terminal of the resonance capacitor.

28. The relay device according to claim 13, wherein a tap is provided to the power relay coil,

and wherein the first terminal is connected to the tap,

and wherein the second terminal is connected to one end of the power relay coil.

29. The relay device according to claim 13, wherein the relay antenna further comprises two resonance capacitors arranged in series with the power relay coil,

and wherein the first terminal is connected to one end of one resonance capacitor from among the aforementioned two resonance capacitors, and the second terminal is connected to the other terminal of the aforementioned one resonance capacitor.

30. The relay device according to claim 13, further comprising a first coil magnetically coupled with the power relay coil,

wherein the first terminal is connected to one end of the first coil, and the second terminal is connected to the other end of the first coil.

31. The relay device according to claim 13, further comprising a transformer having a primary winding connected in series with the relay antenna,

and wherein the first terminal is connected to one end of a secondary winding of the transformer, and the second terminal is connected to the other end of the secondary winding of the transformer.

32. A wireless transmission system comprising:

a wireless power supply apparatus configured to transmit an electric power signal comprising any one from among an electric field component, magnetic field component, and electromagnetic field component;

a wireless power receiving apparatus configured to receive the electric power signal from the wireless power supply apparatus; and

the relay device according to claim 13, arranged between the wireless power supply apparatus and the wireless power receiving apparatus.

33. The wireless power transmission system according to claim 32, wherein a plurality of the relay devices is provided to the wireless power transmission system.

22. A relay device employed in a resonance wireless power transmission system, comprising:

a relay antenna comprising a power relay coil; and

an automatic tuning assist circuit coupled with the relay antenna, and configured to inject a correction current into the relay antenna or otherwise to draw a correction current from the relay antenna,

wherein the automatic tuning assist circuit comprises an auxiliary coil,

and wherein the automatic tuning assist circuit is configured to switch states between (1) a first state in which the auxiliary coil is coupled with the relay antenna so as to inject or otherwise draw, into or otherwise from the relay antenna, a correction current that corresponds to a current that flows through the auxiliary coil, and (2) a second state in which the auxiliary coil is disconnected from the relay antenna such that the current that flows through the auxiliary coil flows through a current path that is independent of the relay antenna.

23. The relay device according to claim 22, wherein the states are switched between the first state and the second state 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.