Contactless power transfer system
First Claim
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1. A contactless power transfer system comprising:
- a power transmission device; and
a power reception device,said power transmission device includinga power transmission unit including a power transmission coil and a first capacitor connected in series to said power transmission coil, and configured to transmit electric power to said power reception device in a contactless manner,a voltage variable high-frequency power supply configured to supply alternating-current (AC) power to said power transmission unit while adjusting a voltage of the voltage variable high-frequency power supply, anda first control unit controlling said voltage variable high-frequency power supply,said power reception device includinga power reception unit including a power reception coil and a second capacitor connected to said power reception coil, and configured to receive electric power from said power transmission unit in a contactless manner,an impedance adjuster provided between said power reception unit and load equipment, anda second control unit controlling said impedance adjuster,said first control unit controlling said voltage variable high-frequency power supply to include a first control region and a second control region, in the first control region the voltage of said voltage variable high-frequency power supply being raised as a coupling coefficient between said power transmission unit and said power reception unit is larger, a coupling coefficient in the second control region being larger than that in the first control region, in the second control region the voltage of said voltage variable high-frequency power supply being maintained at a constant value or substantially at said constant value irrespective of said coupling coefficient, andsaid second control unit controlling said impedance adjuster such that an input impedance of said impedance adjuster becomes equal to a prescribed value or substantially to said prescribed value when said voltage variable high-frequency power supply is controlled in said first control region, and controlling said impedance adjuster such that received electric power becomes close to a target by changing said input impedance from said prescribed value or substantially from said prescribed value when said voltage variable high-frequency power supply is controlled in said second control region.
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Abstract
A power supply ECU controls a converter to have a first control region in which a voltage is raised as a coupling coefficient is larger, and a second control region in which the voltage is maintained at a rating irrespective of a coupling coefficient. An ECU controls a converter such that an input impedance of the converter attains a prescribed value in the first control region and controls the converter such that received electric power becomes close to a target by changing the input impedance in the second control region.
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Citations
7 Claims
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1. A contactless power transfer system comprising:
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a power transmission device; and a power reception device, said power transmission device including a power transmission unit including a power transmission coil and a first capacitor connected in series to said power transmission coil, and configured to transmit electric power to said power reception device in a contactless manner, a voltage variable high-frequency power supply configured to supply alternating-current (AC) power to said power transmission unit while adjusting a voltage of the voltage variable high-frequency power supply, and a first control unit controlling said voltage variable high-frequency power supply, said power reception device including a power reception unit including a power reception coil and a second capacitor connected to said power reception coil, and configured to receive electric power from said power transmission unit in a contactless manner, an impedance adjuster provided between said power reception unit and load equipment, and a second control unit controlling said impedance adjuster, said first control unit controlling said voltage variable high-frequency power supply to include a first control region and a second control region, in the first control region the voltage of said voltage variable high-frequency power supply being raised as a coupling coefficient between said power transmission unit and said power reception unit is larger, a coupling coefficient in the second control region being larger than that in the first control region, in the second control region the voltage of said voltage variable high-frequency power supply being maintained at a constant value or substantially at said constant value irrespective of said coupling coefficient, and said second control unit controlling said impedance adjuster such that an input impedance of said impedance adjuster becomes equal to a prescribed value or substantially to said prescribed value when said voltage variable high-frequency power supply is controlled in said first control region, and controlling said impedance adjuster such that received electric power becomes close to a target by changing said input impedance from said prescribed value or substantially from said prescribed value when said voltage variable high-frequency power supply is controlled in said second control region. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification