Abstract: A wireless power transfer system and a method of operating a multilevel converter for wireless power transfer are disclosed. The wireless power transfer system comprises a multilevel converter with stack inductors that both suppress circulating currents and replace the series inductor of a tuned LCL circuit. A zero voltage switching routine for wireless power transfer is also disclosed.

Abstract: A method and apparatus for controlling an intermediate resonant circuit in a wireless power or IPT system includes regulating a secondary with which the intermediate circuit is magnetically coupled so as to control the VA in the intermediate resonant circuit and to control magnetic leakage fields.

Abstract: The present disclosure relates to a boost active bridge converter, which has particular, but not sole, relevance to a converter for an inductive or capacitive (wireless) power transfer system. According to an embodiment An AC-AC converter is presented. The AC-AC converter comprises a bridge circuit including at least two half-bridge converters, each half bridge converter comprising a first switch at an upper end and a second switch at a lower end, a capacitor connected to each half-bridge converter, the half bridge converters being connected to each other between the respective first switches and second switches thereof, the upper ends of each half bridge converters being connectable to a primary energy source, wherein the converter is operable to provide a controllable AC output.

Abstract: The present disclosure relates to an integrated boost modular multilevel converter, which has particular, but not sole, relevance to a converter for an inductive or capacitive (wireless) power transfer system. More particularly, the present invention according to an embodiment discloses a modular multilevel power converter (MMPC) comprising: at least one submodule stack having an output for connection to a load and an input for connection to an input power source, at least one inductive element provided between the input and the output, the at least one submodule stack including at least two submodules, each submodule comprising at least one capacitor and a plurality of controllable switches, and the submodules being operable to selectively transfer energy from the at least one inductive element to boost a voltage at the output relative to a voltage at the input.

Abstract: An inductive or wireless power transfer coupler array has at least two coupler modules connected in parallel to a common power source. Each coupler module comprises a resonant circuit, including at least one transmitter coil and a capacitive element. Each of the coupler modules is connected to a second terminal of the power source across the respective resonant circuit by a corresponding pair of switching elements, and each coupler module is linked with at least one other coupler module at a shared one switching element of the corresponding pair of switching elements. A control module is configured to effect control between the active state and the passive state by controlling the phase angle of the corresponding pair of switching elements.

Abstract: A resonant inductive power transfer circuit has a power converter to supply to a load, and the converter is concurrently controlled to create a controlled reactance that substantially compensates for variability in the coupling with the another resonant inductive power transfer circuit and/or changes in the load supplied by the power converter.

Abstract: A converter including a bridge circuit having a first leg and a second leg, each leg including a high switch and a low switch, the high switches being connected to a first energy source and the low switches being connected to ground, a coupling network(s) having a first connection between the switches of the first leg and a second connection between the switches of the second leg, and a second (or multiple secondary) energy source(s) connected between the coupling network(s) and ground, wherein the coupling network comprises a first inductive element connected between the second energy source and the switches of the first leg, and a second inductive element connected between the second energy source and the switches of the second leg.

Abstract: The disclosure provides a wireless power transfer circuit that uses two coupled resonators provided in one of a primary or secondary wireless power transfer magnetic structure. The coupled resonators work together to compensate for changes in relative position. Each resonator has a planar coil, and the resonators are coupled with each other by magnetic coupling of the planar coils, which are located adjacent each other in either a side by side relationship or a partially overlapping relationship. The circuit is tolerant to misalignment of the magnetic structures (often referred to as pads) which magnetically couple with each other to enable the transfer of power. The changes in inductances as well as main, cross, and inter coupling between the coils of the primary and pick-up pads or structures show that a constant power transfer or charging profile can be maintained over a large operating region.

Abstract: A polyphase inductive power transfer system primary or secondary apparatus includes a magnetic coupling coil associated with each phase and a compensation network associated with each magnetic coupling coil for providing power to or receiving power from the respective coil. At least one of the compensation networks has a different power transfer characteristic to one or more of the other compensation networks.

Abstract: An inductive or wireless power transfer coupler array has at least two coupler modules connected in parallel to a common power source. Each coupler module comprises a resonant circuit, including at least one transmitter coil and a capacitive element. Each of the coupler modules is connected to a second terminal of the power source across the respective resonant circuit by a corresponding pair of switching elements, and each coupler module is linked with at least one other coupler module at a shared one switching element of the corresponding pair of switching elements. A control module is configured to effect control between the active state and the passive state by controlling the phase angle of the corresponding pair of switching elements.

Abstract: An inductive power transfer system primary or secondary circuit has a first compensation network and second compensation network. The compensation networks each have a different power transfer characteristic with respect to relative movement of the primary or secondary magnetic flux coupling structures. The power transfer characteristics are such that one compensates for the other to allow a smooth or constant overall power transfer is despite the relative movement.

Abstract: An IPT primary or secondary circuit includes a converter connected to a primary energy source and a compensation network. A supplementary energy source is connected to the compensation network and the converter transfers energy between the primary energy source or another IPT primary or secondary circuit and the supplementary energy source.

Abstract: An inductive power transfer system primary or secondary circuit has a first compensation network and second compensation network. The compensation networks each have a different power transfer characteristic with respect to relative movement of the primary or secondary magnetic flux coupling structures. The power transfer characteristics are such that one compensates for the other to allow a smooth or constant overall power transfer is despite the relative movement.

Abstract: The disclosure provides a wireless power transfer circuit that uses two coupled resonators provided in one of a primary or secondary wireless power transfer magnetic structure. The coupled resonators work together to compensate for changes in relative position. Each resonator has a planar coil, and the resonators are coupled with each other by magnetic coupling of the planar coils, which are located adjacent each other in either a side by side relationship or a partially overlapping relationship. The circuit is tolerant to misalignment of the magnetic structures (often referred to as pads) which magnetically couple with each other to enable the transfer of power. The changes in inductances as well as main, cross, and inter coupling between the coils of the primary and pick-up pads or structures show that a constant power transfer or charging profile can be maintained over a large operating region.

Abstract: The present disclosure relates to a boost active bridge converter, which has particular, but not sole, relevance to a converter for an inductive or capacitive (wireless) power transfer system. According to an embodiment An AC-AC converter is presented. The AC-AC converter comprises a bridge circuit including at least two half-bridge converters, each half bridge converter comprising a first switch at an upper end and a second switch at a lower end, a capacitor connected to each half-bridge converter, the half bridge converters being connected to each other between the respective first switches and second switches thereof, the upper ends of each half bridge converters being connectable to a primary energy source, wherein the converter is operable to provide a controllable AC output.

Abstract: The present disclosure relates to an integrated boost modular multilevel converter, which has particular, but not sole, relevance to a converter for an inductive or capacitive (wireless) power transfer system. More particularly, the present invention according to an embodiment discloses a modular multilevel power converter (MMPC) comprising: at least one submodule stack having an output for connection to a load and an input for connection to an input power source, at least one inductive element provided between the input and the output, the at least one submodule stack including at least two submodules, each submodule comprising at least one capacitor and a plurality of controllable switches, and the submodules being operable to selectively transfer energy from the at least one inductive element to boost a voltage at the output relative to a voltage at the input.

Abstract: The present invention relates to a AC-AC converter, which has particular relevance to a converter for an inductive or capacitive (wireless) power transfer system. More specifically, the current invention discloses an AC-AC converter comprising a bridge circuit having a first leg and a second leg, each leg including a high switch and a low switch, the high switches being connected to a first energy source and the low switches being connected to ground, a coupling network(s) having a first connection between the switches of the first leg and a second connection between the switches of the second leg, a second (or multiple secondary) energy source(s) connected between the coupling network(s) and ground.

Abstract: A polyphase inductive power transfer system primary or secondary apparatus includes a magnetic coupling coil associated with each phase and a compensation network associated with each magnetic coupling coil for providing power to or receiving power from the respective coil. At least one of the compensation networks has a different power transfer characteristic to one or more of the other compensation networks.

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.

Abstract: The present invention provides a polyphase inductive power transfer (IPT) system comprising a primary power supply comprising a plurality of primary conductors, the primary conductors being individually selectively operable to provide or receive a magnetic field for inductive power transfer; and at least one pick-up comprising one or more pick-up conductors, the one or more pick-up conductors each being individually selectively operable to magnetically couple with a primary conductor to control power transfer between the primary power supply and a load coupled or coupleable with the respective pick-up. The polyphase primary power supply may be used to power a plurality of single-phase pick-ups, one or more polyphase pick-ups, or a combination thereof. Also disclosed are polyphase primary and secondary converters for use in such a system.