Power generation system and power generating unit

• US 9,013,069 B2
• Filed: 10/06/2011
• Issued: 04/21/2015
• Est. Priority Date: 10/08/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Yamamoto, Hiroshi, Kanno, Hiroshi
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Barnett, Joel
• Application Number:
  US13/267,090
• Publication Number:
  US 20120086283A1
• Time in Patent Office: 1,293 Days
• Field of Search: 307/104
• US Class Current: 307/104
• 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 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas

Abstract

The power generation system includes first and second power generating units, each of which converts DC energy into RF energy and transmits the power wirelessly, a combining section, which combines the respective outputs of the power generating units together, and an oscillation phase control section, which reduces the phase difference between the RF energies supplied from the two power generating units and. The oscillation phase control section controls a phase difference between the RF energies supplied from the oscillators and belonging to the first and second power generating units and, respectively, so that first and second RF energies supplied from the first and second power generating units and are in phase with each other when combined together by the combining section.

Claims

1. A power generation system comprising:

first and second power generating units, each of which includes;

a power generating device that outputs DC energy;

an oscillator that converts the DC energy supplied from the power generating device into RF energy having a frequency f0 and that outputs the RF energy;

a power transmitting antenna that transmits the RF energy supplied from the oscillator; and

a power receiving antenna that receives at least a part of the RF energy that has been transmitted by the power transmitting antenna, the resonant frequencies of the power transmitting and power receiving antennas being set to be equal to the frequency f0, the power generating unit outputting the RF energy that has been received by the power receiving antenna;

a combining section that receives and combines the RF energies supplied from those power generating units and outputs combined RF energy; and

an oscillation phase control section that controls the oscillators belonging to the first and second power generating units to control a phase difference between the RF energies supplied from the oscillators belonging to the first and second power generating units, respectively, so that first and second RF energies supplied from the first and second power generating units are in phase with each other prior to being combined together by the combining section.

2. The power generation system of claim 1, wherein in each said power generating unit, the power transmitting antenna is a series resonant circuit and the power receiving antenna is a parallel resonant circuit.

3. The power generation system of claim 1, wherein the oscillation phase control section includes:

a first pulse generator, which generates a pulse that defines the phase of the RF energy supplied from the oscillator belonging to the first power generating unit and which applies the pulse to that oscillator;

a second pulse generator, which generates a pulse that defines the phase of the RF energy supplied from the oscillator belonging to the second power generating unit and which applies the pulse to that oscillator; and

a pulse control section, which instructs the first and second pulse generators exactly when to generate the pulse.

4. The power generation system of claim 1, wherein the phase difference between the RF energies supplied from the oscillators belonging to the first and second power generating units, respectively, has been set based on a difference in the length of a transmission line from the power receiving antenna to the combining section between the first and second power generating units.

5. The power generation system of claim 1, wherein each said power generating unit includes an impedance control section, which changes at least one of the input impedance of the oscillator, the input impedance of the power transmitting antenna and the output impedance of the power receiving antenna according to a variation in the output impedance of the power generating device, and

wherein the oscillation phase control section controls a phase difference between the RF energies supplied from the oscillators belonging to the first and second power generating units, respectively, so that if the impedance control section has changed at least one of the input impedance of the oscillator, the input impedance of the power transmitting antenna and the output impedance of the power receiving antenna, the first and second RF energies are in phase with each other when combined together by the combining section.

6. The power generation system of claim 5, wherein each said power generating unit includes a measuring section for measuring the output current and output voltage of its power generating device, and

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

7. The power generation system of claim 5, comprising a phase shift data memory that stores information indicating how the magnitude of a phase shift between the first and second RF energies being combined by the combining section changes as the output impedance of the power generating device of each said power generating unit varies,

wherein the oscillation phase control section controls the phases of the RF energies supplied from the oscillators belonging to the first and second power generating units, respectively, by reference to the information that is stored in the phase shift data memory so that those energies are in phase with each other.

8. The power generation system of claim 1, comprising a power converting section that converts the output of the combining section into either DC or AC energy with a frequency of 60 Hz or less and then outputs the DC or AC energy.

9. The power generation system of claim 8, wherein in each said power generating unit, the respective input impedances of the oscillator and the power transmitting antenna, the output impedance of the power receiving antenna and the voltage step-up ratio of the power generating unit itself are defined so that the power converting section has an output voltage of 200 to 300 V.

10. The power generation system of claim 1, wherein the power generating device belonging to each said power generating unit is a solar power generating device.

11. The power generation system of claim 10, wherein the solar power generating device uses crystalline silicon.

12. The power generation system of claim 10, wherein in each said power generating unit, the power generating device and the power transmitting antenna are arranged outside of a building, and the power receiving antenna is installed inside of the building.

13. The power generation system of claim 10, wherein in each said power generating unit, the power generating device, the power transmitting antenna and the power receiving antenna are arranged outside of a building, and the power transmitting and power receiving antennas are arranged so as to face each other at least partially.

14. The power generation system of claim 1, wherein if in each said power generating unit, the oscillator has a voltage step-up ratio Voc, the power transmitting antenna has an inductance L1, the power receiving antenna has an inductance L2, and the power transmitting and power receiving antennas have a coupling coefficient k,

each said power generating unit satisfies (L2/L1)≧

4(k/Voc)².

16. A power generating unit for use in the power generating system of claim 1, the power generating unit comprising:

a power generating device that outputs DC energy;

an oscillator that converts the DC energy supplied from the power generating device into RF energy having a frequency f0 and which outputs the RF energy;

a pulse generator that generates a pulse that defines the phase of the RF energy supplied from the oscillator and which applies the pulse to that oscillator, the pulse generator including an input section that receives an externally input control signal and generating the pulse in response to the input of the control signal, the control signal being determined so as to make the phase of the RF energy output from the power generating unit be in phase with a phase of RF energy output from another power generating unit in the power generating system;

a power transmitting antenna that transmits the RF energy supplied from the oscillator; and

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

wherein the resonant frequencies of the power transmitting and power receiving antennas are set to be equal to the frequency f0, and

wherein the power generating unit outputs the RF energy that has been received by the power receiving antenna.

15. A power generation system comprising:

first and second power generating units, each of which includes;

a power generating device, which outputs DC energy;

an oscillator that converts the DC energy supplied from the power generating device into RF energy having a frequency f0 and that outputs the RF energy;

a power transmitting antenna that transmits the RF energy supplied from the oscillator; and

a power receiving antenna that receives at least a part of the RF energy that has been transmitted by the power transmitting antenna, the resonant frequencies of the power transmitting and power receiving antennas being set to be equal to the frequency f0, the power generating unit outputting the RF energy that has been received by the power receiving antenna;

a combining section that receives and combines the RF energies supplied from those power generating units and outputs combined RF energy; and

a reactance control circuit that is inserted to a transmission line between the oscillator and the power transmitting antenna in at least one of the first and second power generating units, the reactance control circuit including an inductor and/or a capacitor and setting a reactance value so that the first and second RF energies that have been supplied from the first and second power generating units are in phase with each other when combined by the combining section.