POWER TRANSMISSION DEVICE AND WIRELESS POWER TRANSMISSION SYSTEM INCLUDING THE SAME
First Claim
1. A power transmission device comprising:
- a first coil;
a first resonance coil;
a detector; and
a control device,wherein the first coil is connected to a high-frequency power source through a coupler,wherein the first resonance coil is connected to a variable capacitor and is electromagnetically coupled with the first coil, and electromagnetic resonance occurs between the first resonance coil and a second resonance coil electromagnetically coupled with a second coil in a power receiving device,wherein the detector detects intensity of an S11 parameter output from the coupler, andwherein the control device has a function of changing a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of the second resonance coil, sets a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets the oscillation frequency of the signal output from the high-frequency power source as the resonance frequencies of the first resonance coil and the second resonance coil.
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Accused Products
Abstract
Not a structure in which a resonance frequency of a power transmission device is set after a resonance frequency of a power receiving device is directly measured but a structure in which the resonance frequencies of the power receiving device and the power transmission device are estimated after reflection of an electromagnetic field for transmitting electric power to the power receiving device is monitored by the power transmission device is employed. After a capacitance value of a variable capacitor in a resonance coil of the power receiving device is once set to 0, an S11 parameter is detected while a frequency of an electromagnetic wave is changed, and the resonance frequency of the power transmission device is estimated on the basis of the S11 parameter.
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Citations
10 Claims
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1. A power transmission device comprising:
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a first coil; a first resonance coil; a detector; and a control device, wherein the first coil is connected to a high-frequency power source through a coupler, wherein the first resonance coil is connected to a variable capacitor and is electromagnetically coupled with the first coil, and electromagnetic resonance occurs between the first resonance coil and a second resonance coil electromagnetically coupled with a second coil in a power receiving device, wherein the detector detects intensity of an S11 parameter output from the coupler, and wherein the control device has a function of changing a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of the second resonance coil, sets a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets the oscillation frequency of the signal output from the high-frequency power source as the resonance frequencies of the first resonance coil and the second resonance coil. - View Dependent Claims (2)
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3. A power transmission device comprising:
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a first coil; a first resonance coil; a detector; and a control device, wherein the first coil is connected to a high-frequency power source through a coupler, wherein the first resonance coil is connected to a variable capacitor and is electromagnetically coupled with the first coil, and electromagnetic resonance occurs between the first resonance coil and a second resonance coil electromagnetically coupled with a second coil in a power receiving device, wherein the detector detects intensity of an S11 parameter output from the coupler, and wherein the control device has a function of changing a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of the second resonance coil, sets a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is set to a capacitance value based on the resonant frequency of the second resonance coil, as the oscillation frequency of the signal output from the high-frequency power source. - View Dependent Claims (4)
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5. A wireless power transmission system comprising a power transmission device and a power receiving device,
wherein the power transmission device comprising: -
a first coil; a first resonance coil; a detector; and a control device, wherein the first coil is connected to a high-frequency power source through a coupler, wherein the first resonance coil is electromagnetically coupled with the first coil and is connected to a variable capacitor, wherein the detector detects intensity of an S11 parameter output from the coupler, wherein the control device has a function of changing a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of a second resonance coil, sets a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets the oscillation frequency of the signal output from the high-frequency power source as the resonance frequencies of the first resonance coil and the second resonance coil, and wherein the power receiving device includes the second resonance coil which causes electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is electromagnetically coupled with the second resonance coil and is connected to a load. - View Dependent Claims (6)
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7. A wireless power transmission system comprising a power transmission device and a power receiving device,
wherein the power transmission device comprising: -
a first coil; a first resonance coil; a detector; and a control device, wherein the first coil is connected to a high-frequency power source through a coupler, wherein the first resonance coil is electromagnetically coupled with the first coil and is connected to a variable capacitor, wherein the detector detects intensity of an S11 parameter output from the coupler, wherein the control device has a function of changing a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of a second resonance coil, sets a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is set to a capacitance value based on the resonant frequency of the second resonance coil, as the oscillation frequency of the signal output from the high-frequency power source, and wherein the power receiving device includes the second resonance coil which causes electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is electromagnetically coupled with the second resonance coil and is connected to a load. - View Dependent Claims (8)
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9. A wireless power transmission system comprising a power transmission device and a power receiving device,
wherein the power transmission device comprising: -
a first coil; a first resonance coil; a detector; and a control device, wherein the first coil is connected to a high-frequency power source through a coupler, wherein the first resonance coil is electromagnetically coupled with the first coil and is connected to a variable capacitor, wherein the power receiving device includes a second resonance coil which causes electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is electromagnetically coupled with the second resonance coil and is connected to a load. - View Dependent Claims (10)
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Specification