Primary-side power control for inductive power transfer
First Claim
1. A method of controlling an output voltage of a pickup in an inductive power transfer (IPT) system comprising the pickup, a power supply, and a primary conductive path with an unknown or variable mutual coupling between the pickup and the primary conductive path, the method comprising steps of:
- deriving an estimate of the unknown or variable mutual coupling between the primary conductive path and the pickup from a voltage across the primary conductive path;
deriving an estimate of the output voltage of the pickup based at least in part on the voltage across the primary conductive path and the estimated unknown or variable mutual coupling; and
adjusting a current in the primary conductive path so that the estimated pickup output voltage matches a required pickup output voltage, by controlling a voltage supplied to the primary conductive path by the power supply.
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Accused Products
Abstract
A method is provided for controlling the output voltage of a pickup in an inductive power transfer (IPT) system without any additional form of communications for feedback from the pickup to the power supply. The method comprising the steps of deriving an estimate of the output voltage of the pickup from the voltage across the primary conductive path, and adjusting the current in the primary conductive path so that the estimated pickup output voltage matches a required pickup output voltage. In particular, an estimate of the pickup output voltage is derived from the magnitude and phase angle of the voltage in the primary conductive path.
22 Citations
13 Claims
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1. A method of controlling an output voltage of a pickup in an inductive power transfer (IPT) system comprising the pickup, a power supply, and a primary conductive path with an unknown or variable mutual coupling between the pickup and the primary conductive path, the method comprising steps of:
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deriving an estimate of the unknown or variable mutual coupling between the primary conductive path and the pickup from a voltage across the primary conductive path; deriving an estimate of the output voltage of the pickup based at least in part on the voltage across the primary conductive path and the estimated unknown or variable mutual coupling; and adjusting a current in the primary conductive path so that the estimated pickup output voltage matches a required pickup output voltage, by controlling a voltage supplied to the primary conductive path by the power supply. - View Dependent Claims (2, 3, 4)
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5. A power supply comprising an inverter, a resonant tank electrically coupled with an output of the inverter, and a power controller adapted to control operation of the inverter to control an output voltage of a pickup inductively coupled with the power supply, wherein the power controller is adapted to:
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derive an estimate of an unknown or variable mutual coupling between a primary conductive path and the pickup from a voltage across the primary conductive path; derive an estimate of the output voltage of the pickup based at least in part on the voltage across the primary conductive path and the estimated unknown or variable mutual coupling; and adjust a current in the primary conductive path so that the estimated pickup output voltage matches a required pickup output voltage, by controlling a voltage supplied to the primary conductive path by the power supply.
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6. An inductive power transfer (IPT) system comprising a power supply and a pickup for inductive coupling with the power supply, wherein the power supply comprises an inverter, a resonant tank electrically coupled with an output of the inverter, and a power controller adapted to control operation of the inverter to control an output voltage of the pickup inductively coupled with the power supply wherein the power controller is adapted to:
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derive an estimate of an unknown or variable mutual coupling between a primary conductive path and the pickup from a voltage across the primary conductive path; derive an estimate of the output voltage of the pickup based at least in part on the voltage across the primary conductive path and the estimated unknown or variable mutual coupling; and adjust a current in the primary conductive path so that the estimated pickup output voltage matches a required pickup output voltage, by controlling a voltage supplied to the primary conductive path by the power supply.
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7. A power supply for inductive coupling with a pickup via a primary conductive path in an inductive power transfer (IPT) system with an unknown or variable mutual coupling between the pickup and the primary conductive path, the power supply comprising:
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an inverter; a resonant tank electrically coupled with an output of the inverter and comprising a tuning capacitor and the primary conductive path; and a power controller adapted to derive from a voltage across the primary conductive path an estimate of the unknown or variable mutual coupling between the primary conductive path and the pickup inductively coupled with the power supply in use, and derive an estimate of an output voltage of the pickup based at least in part on the estimated unknown or variable mutual coupling and the voltage across the primary conductive path. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification