Method and apparatus for control of inductively coupled power transfer systems
AssigneeAuckland Uniservices Limited
InventorsStephan H Hussmann, Aiguo Hu
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Abstract
A power pick-up for an Inductively Coupled Power Transfer (ICPT) system is provided having a resonant pick up circuit. The natural frequency of the pick-up circuit may be varied by controlling the conductance or capacitance of a variable reactive in the resonant circuit. The load being supplied by the pick-up circuit is sensed, and the effective capacitance or inductance of the variable reactive component is controlled to vary the natural resonant frequency of the pick-up circuit to thereby control the power flow into the pick-up to satisfy the power required by the load.
Claims48
An inductively coupled power transfer pick-up comprising:
- a pick-up resonant circuit comprising a capacitive element and an inductive element adapted to receive power from a magnetic field associated with a primary conductive path to supply a load, one of the capacitive element and the inductive element comprising a controlled reactive element;
- a phase device configured to sense the phase of a voltage or current in the pick-up resonant circuit;
- a sensor configured to sense a power requirement of the load;
- and
- a controller configured to selectively tune or de-tune the pick-up resonant circuit in response to the load power requirement sensed by the sensor by selectively electrically connecting or disconnecting the controlled reactive element to or from the pick-up resonant circuit in each cycle of the voltage or current dependent on the sensed phase to vary the effective capacitance or inductance of the controlled reactive element of the pick-up resonant circuit to control the transfer of power to the pick-up resonant circuit dependant on the sensed load power requirement.
An inductively coupled power transfer system comprising:
- a power supply comprising a resonant converter to provide alternating current to a primary conductive path of the inductively coupled power transfer system;
- one or more inductively coupled power transfer system pick-up devices, each of said pick-up devices comprising a pick-up resonant circuit comprising:
- a capacitive element;
- and
- an inductive element adapted to receive power from a magnetic field associated with a primary conductive path to supply a load;
- a phase device configured to sense the phase of a voltage or current in the pick-up resonant circuit;
- a sensor configured to sense a power requirement of the load;
- and
- a controller configured to selectively tune or de-tune the pick-up resonant circuit in response to the load power requirement sensed by the sensor by selectively electrically connecting or disconnecting the controlled reactive element to or from the pick-up resonant circuit in each cycle of the voltage or current dependent on the sensed phase to vary the effective capacitance or inductance of the controlled reactive element of the pick-up resonant circuit to control the transfer of power to the pick-up resonant circuit dependant on the sensed load power requirement.
A method for controlling power drawn by an inductively coupled power transfer pick-up, the method comprising the steps of:
- sensing the phase of a voltage or current in a pick-up resonant circuit;
- sensing a power requirement of a load supplied by the pick-up resonant circuit;
- and
- selectively tuning or detuning the pick-up resonant circuit in response to the power requirement sensed by the sensor by selectively electrically connecting or disconnecting the controlled reactive element to or from the pick-up resonant circuit in each cycle of the voltage or current dependent on the sensed phase to vary the effective capacitance or inductance of a controlled reactive element of the pick-up resonant circuit to thereby control the transfer of power to the pick-up resonant circuit dependant on the sensed load power requirement.
Dependencies are inferred from the claim text.