POWER GENERATING APPARATUS, POWER GENERATING SYSTEM, AND WIRELESS ELECTRIC POWER TRANSMISSION APPARATUS

• US 20110266882A1
• Filed: 05/02/2011
• Published: 11/03/2011
• Est. Priority Date: 05/03/2010
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: KANNO, Hiroshi, YAMAMOTO, Hiroshi
• Granted Patent: US 8,829,728 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 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A power generator includes: a power generating section 101 that outputs DC energy; an oscillating section 102 that converts the DC energy into RF energy with a frequency f0; a power-transmitting antenna 107 that transmits the RF energy; a power-receiving antenna 108 that receives at least a part of the RF energy that has been transmitted by the power-transmitting antenna 107; and a transmitting-end control section 110 that matches the input impedance of the oscillating section 102 to the output impedance of the power generating section 101 by changing the input impedance of the oscillating section 102 in accordance with a variation in the output impedance of the power generating section 101. The power-transmitting antenna 107 is a series resonant circuit, and the power-receiving antenna 108 is a parallel resonant circuit. And the resonant frequencies fT and fR of the power-transmitting and power-receiving antennas 107 and 108 are both set to be equal to the frequency f0 of the RF energy.

Claims

1. A power generator comprising:

a power generating section that outputs DC energy;

an oscillating section that converts the DC energy into RF energy with a frequency f0;

a power-transmitting antenna that transmits the RF energy;

a power-receiving antenna that receives at least a part of the RF energy that has been transmitted by the power-transmitting antenna;

a rectifying section that converts the RF energy that has been received by the power-receiving antenna into DC energy; and

a transmitting-end control section that matches the input impedance of the oscillating section to the output impedance of the power generating section by changing the input impedance of the oscillating section in accordance with a variation in the output impedance of the power generating section,

wherein the power-transmitting antenna is a series resonant circuit,

the power-receiving antenna is a parallel resonant circuit, and

resonant frequencies fT and fR of the power-transmitting and power-receiving antennas, respectively, are both set to be equal to the frequency f0 of the RF energy.

2. The power generator of claim 1, further comprising a measuring section that measures the output current and output voltage of the power generating section,

wherein the output impedance value of the power generating section is detected based on the output current and output voltage that have been measured by the measuring section.

3. The power generator of claim 1, further comprising an impedance matching section for oscillating section, which is arranged between the oscillating section and the power-transmitting antenna in order to match the input impedance of the power-transmitting antenna to the output impedance of the oscillating section,

wherein if the output impedance of the power generating section varies, the transmitting-end control section changes the input impedance of the impedance matching section for oscillating section accordingly, thereby matching the input impedance of the impedance matching section for oscillating section to the output impedance of the oscillating section.

4. The power generator of claim 3, wherein if the output impedance of the power generating section varies, the transmitting-end control section changes the input impedance of the power-transmitting antenna accordingly, thereby matching the input impedance of the power-transmitting antenna to the output impedance of the impedance matching section for oscillating section.

5. The power generator of claim 1, wherein the oscillating section includes multiple oscillators having respective predefined input impedance ranges, and

wherein the transmitting-end control section chooses one of the oscillators according to the output impedance value of the power generating section and makes current flow through the oscillator chosen, thereby changing the input impedance of the oscillating section.

6. The power generator of claim 3, wherein the impedance matching section for oscillating section includes multiple matching circuits having respective predefined input impedance ranges, and

wherein the transmitting-end control section chooses one of the matching circuits according to the output impedance value of the oscillating section and makes current flow through the matching circuit chosen, thereby changing the input impedance of the impedance matching section for oscillating section.

7. The power generator of claim 3, wherein the impedance matching section for oscillating section includes multiple capacitors and multiple inductors, and

wherein the transmitting-end control section chooses a combination including one of the capacitors and one of the inductors according to the output impedance value of the oscillating section, and makes current flow through the capacitor and the inductor that are included in the chosen combination, thereby changing the input impedance of the impedance matching section for oscillating section.

8. The power generator of claim 4, wherein the power-transmitting antenna includes multiple inductors that are connected together in series and multiple capacitors that are connected in series to the inductors, and

wherein the transmitting-end control section chooses at least one of the inductors and at least one of the capacitors according to the output impedance value of the power generating section, and makes current flow through the at least one inductor chosen and the at least one capacitor chosen, thereby changing the input impedance of the power-transmitting antenna.

9. The power generator of claim 4, wherein the power-transmitting antenna includes:

at least two inductors, which have mutually different inductances and which are arranged in parallel with each other; and

another inductor, which is arranged in the vicinity of the at least two inductors, and

wherein the transmitting-end control section chooses one of the at least two inductors according to the output impedance value of the power generating section, and makes current flow through the chosen inductor, thereby changing the input impedance of the power-transmitting antenna.

10. The power generator of claim 4, wherein the power-transmitting antenna includes an inductor, multiple capacitors that are connected in series to the inductor, and a movable portion with a metallic or magnetic body, and

wherein the transmitting-end control section changes the distance between the inductor and the movable portion, and chooses at least one of the capacitors, according to the output impedance value of the power generating section, and makes current flow through the at least one capacitor chosen, thereby changing the input impedance of the power-transmitting antenna.

11. The power generator of claim 4, wherein the power-transmitting antenna includes multiple resonators, which have mutually different input impedances, and

wherein the transmitting-end control section chooses one of the resonators according to the output impedance value of the power generating section, and makes current flow through the resonator chosen, thereby changing the input impedance of the power-transmitting antenna.

12. The power generator of claim 1, further comprising:

a impedance matching section for rectifying section, which is arranged between the power-receiving antenna and the rectifying section in order to match the input impedance of the rectifying section to the output impedance of the power-receiving antenna; and

a receiving-end control section that matches the input impedance of the impedance matching section for rectifying section to the output impedance of the power-receiving antenna by changing the input impedance of the impedance matching section for rectifying section in accordance with a variation in the output impedance of the power generating section.

13. The power generator of claim 12, wherein if the output impedance of the power generating section varies, the receiving-end control section changes the input impedance of the rectifying section accordingly, thereby matching the input impedance of the rectifying section to the output impedance of the impedance matching section for rectifying section.

14. The power generator of claim 12, wherein if the output impedance of the power generating section varies, the receiving-end control section changes the output impedance of the power-receiving antenna accordingly, thereby matching the output impedance of the power-receiving antenna to the input impedance of the impedance matching section for rectifying section.

15. The power generator of claim 12, further comprising an environmental condition sensing section that measures an environmental parameter of the power generating section,

wherein if the environmental parameter that has been measured by the environmental condition sensing section varies, the receiving-end control section changes the input impedance of the impedance matching section for rectifying section accordingly, thereby matching the input impedance of the impedance matching section for rectifying section to the output impedance of the power-receiving antenna.

16. The power generator of claim 15, wherein if the environmental parameter that has been measured by the environmental condition sensing section varies, the receiving-end control section changes the input impedance of the rectifying section accordingly, thereby matching the input impedance of the rectifying section to the output impedance of the impedance matching section for rectifying section.

17. The power generator of claim 15, wherein if the environmental parameter that has been measured by the environmental condition sensing section varies, the receiving-end control section changes the output impedance of the power-receiving antenna accordingly, thereby matching the output impedance of the power-receiving antenna to the input impedance of the impedance matching section for rectifying section.

18. The power generator of claim 12, wherein the impedance matching section for rectifying section includes multiple matching circuits, which have had their input impedance ranges defined in advance, and

wherein the receiving-end control section chooses one of those matching circuits and makes current flow through the matching circuit chosen, thereby changing the input impedance of the impedance matching section for rectifying section.

19. The power generator of claim 12, wherein the impedance matching section for rectifying section includes multiple capacitors and multiple inductors, and

wherein the receiving-end control section chooses a combination including one of the capacitors and one of the inductors and makes current flow through the capacitor and the inductor that are included in the chosen combination, thereby changing the input impedance of the impedance matching section for rectifying section.

20. The power generator of claim 12, wherein the rectifying section includes multiple rectifiers, which have had their input impedance ranges defined in advance, and

wherein the receiving-end control section chooses one of those rectifiers and makes current flow through the rectifier chosen, thereby changing the input impedance of the rectifying section.

21. The power generator of claim 12, wherein the power-receiving antenna includes multiple inductors that are connected together in series and multiple capacitors that are arranged in parallel with the inductors, and

wherein the receiving-end control section chooses at least one of the inductors and at least one of the capacitors and makes current flow through the at least one inductor chosen and the at least one capacitor chosen, thereby changing the output impedance of the power-receiving antenna.

22. The power generator of claim 12, wherein the power-receiving antenna includes:

at least two inductors, which have mutually different inductances and which are arranged in parallel with each other; and

another inductor, which is arranged in the vicinity of the at least two inductors, and

wherein the receiving-end control section chooses one of the at least two inductors and makes current flow through the chosen inductor, thereby changing the output impedance of the power-receiving antenna.

23. The power generator of claim 12, wherein the power-receiving antenna includes an inductor, multiple capacitors that are arranged in parallel with the inductor, and a movable portion with a metallic or magnetic body, and

wherein the receiving-end control section changes the distance between the inductor and the movable portion, chooses at least one of the capacitors and makes current flow through the at least one capacitor chosen, thereby changing the output impedance of the power-receiving antenna.

24. The power generator of claim 12, wherein the power-receiving antenna includes multiple resonators, which have mutually different input impedances, and

wherein the receiving-end control section chooses one of the resonators and makes current flow through the resonator chosen, thereby changing the output impedance of the power-receiving antenna.

25. The power generator of claim 15, wherein the environmental parameter includes a parameter representing the irradiance of the sunlight received at the power generating section.

26. The power generator of claim 15, wherein the environmental parameter includes a parameter representing the temperature of the power generating section.

27. The power generator of claim 15, wherein the environmental parameter measured by the environmental condition sensing section is transmitted wirelessly to the receiving-end control section.

28. The power generator of claim 1, wherein the power generating section is a solar power generating section.

29. The power generator of claim 28, wherein the solar power generating section generates electric power by using crystalline silicon.

30. The power generator of claim 28, wherein the solar power generating section and the power-transmitting antenna are arranged outside of a building and the power-receiving antenna is arranged inside of the building.

31. The power generator of claim 28, wherein the solar power generating section, the power-transmitting antenna, and the power-receiving antenna are arranged outside of a building, and

wherein the power-transmitting and power-receiving antennas are arranged so as to face each other at least partially.

32. The power generator of claim 1, wherein if the voltage step up ratio of the oscillating section is Voc, the inductance of the power-transmitting antenna is L1, the inductance of the power-receiving antenna is L2, and a coupling coefficient between the power-transmitting and power-receiving antennas is k, (L2/L1)≧

4 (k/Voc)² is satisfied.

33. The power generator of claim 32, wherein the rectifying section has an output voltage of 200 V to 300 V.

34. A power generation system comprising a number of power generators,

wherein at least two of the power generators have their output terminals arranged in parallel with each other, and

wherein the at least two power generators are as defined by claim 1.

35. A wireless power transmission system comprising:

an oscillating section that converts DC energy into RF energy with a frequency f0;

a power-transmitting antenna that transmits the RF energy;

a power-receiving antenna that receives at least a part of the RF energy that has been transmitted by the power-transmitting antenna;

a rectifying section that converts the RF energy that has been received by the power-receiving antenna into DC energy; and

a transmitting-end control section that matches the input impedance of the oscillating section to the output impedance of a power generating section by changing the input impedance of the oscillating section in accordance with a variation in the output impedance of the power generating section,

wherein the power-transmitting antenna is a series resonant circuit, and

wherein the power-receiving antenna is a parallel resonant circuit, and

wherein the resonant frequencies fT and fR of the power-transmitting and power-receiving antennas are both set to be equal to the frequency f0 of the RF energy.