Resonant frequency compensation
AssigneeAuckland Uniservices Limited
InventorsUdaya Kumara Madawala, Duleepa Jayanath Thrimawithana
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Abstract
A wireless power transfer apparatus has a resonant circuit electrically coupled to a power converter. The resonant circuit includes a magnetic coupler Lpt for magnetic coupling with a second apparatus. A controller associated with the power converter is configured to vary a relative phase of operation of the power converter with respect to the second apparatus, the phase being varied to at least partially compensate for variations in a resonant frequency of the resonant circuit.
Claims38
A wireless power transfer apparatus suitable for magnetic coupling with a second apparatus, the wireless power transfer apparatus comprising:
- a power converter electrically coupled or coupleable with a power source or load;
- a resonant circuit electrically coupled with the power converter and comprising a magnetic coupler for magnetic coupling with the second apparatus;
- and
- a controller associated with the power converter and configured to vary a relative phase of operation of the power converter with respect to the second apparatus, the phase being varied to at least partially compensate for variations in a reactive impedance,
- wherein the wireless power transfer apparatus is configured to compensate for changes in the inductance of the magnetic coupler caused by misalignment of the magnetic coupler relative to the second apparatus.
A method for controlling a first wireless power transfer apparatus magnetically coupled or coupleable with a second wireless power transfer apparatus, the method comprising:
- while respective coils of the first wireless power transfer apparatus and the second wireless power transfer apparatus are misaligned, varying a relative phase of operation of the first wireless power transfer apparatus with respect to the second wireless power transfer apparatus to compensate a reactive impedance of the first wireless power transfer apparatus, thereby compensating for changes in the inductance of the first wireless power transfer apparatus caused by the misalignment, wherein
- the coils remain misaligned.
A method of operating a loosely coupled resonant inductive power transfer system, the method comprising controlling a reactive component of a load impedance, caused by mutual inductance between a first resonant inductive power transfer apparatus and a second resonant inductive power transfer apparatus while respective coils of the first resonant inductive power transfer apparatus and the second inductive power transfer apparatus are misaligned, to a non-zero value to compensate for the misalignment between the second resonant inductive power transfer apparatus and the first resonant inductive power transfer apparatus that detunes in the loosely coupled resonant inductive power transfer system, wherein the method includes varying a relative phase of operation of the first resonant inductive power transfer apparatus with respect to the second resonant inductive power transfer apparatus to compensate a reactive impedance of the first resonant inductive power transfer apparatus.
A method comprising reflecting a controlled compensatory reactive impedance, from a second resonant wireless power transfer apparatus to a first resonant wireless power transfer apparatus, while respective coils of the second resonant wireless power transfer apparatus and the first resonant wireless power transfer apparatus are misaligned, that is loosely coupled with the second resonant wireless power transfer apparatus, to compensate the first resonant wireless power transfer apparatus to unity power factor so as to compensate for the misalignment of the coils, wherein the method further comprises controlling a relative phase angle between a second resonant wireless power transfer apparatus converter and a first resonant wireless power transfer apparatus converter.
Dependencies are inferred from the claim text.