Abstract: An IPT system magnetic flux pad includes two substantially planar coils (17) in close proximity to each other above a magnetically permeable core (14). The coils (17) each define a pole area (11, 12) and the distance between one or more adjacent turns of the coils (17) located in a region between the pole areas (11, 12) being different from the distance between one or more adjacent turns of the coils (17) located outside the region between the pole areas (11, 12).

Abstract: An IPT track arrangement including a power supply and conductor electrically connected to the power supply, the conductor includes a plurality of loops located substantially adjacent one another, wherein the polarity in adjacent portions of the loops is the same, and wherein the power supply includes a one or more inverters which share the track load.

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: An IPT system magnetic flux pad includes two substantially planar coils (17) in close proximity to each other above a magnetically permeable core (14). The coils (17) each define a pole area (11, 12) and the distance between one or more adjacent turns of the coils (17) located in a region between the pole areas (11, 12) being different from the distance between one or more adjacent turns of the coils (17) located outside the region between the pole areas (11, 12).

Abstract: A wireless coupling structure has a first layer comprising a flux coupling coil having two opposing end regions separated by two opposing side regions; a second layer comprising a first block of ferrite and a second block of ferrite; and a third layer comprising a leakage flux control coil. The first block is provided next to one of the end regions and the second block is provided next to the other of the end regions.

Abstract: A roadway powered electric vehicle system includes a power supply (101) which makes power available inductively to one or more modules (111) provided in or under a roadway. Modules (111) make a magnetic field selectively available to one or more vehicles travelling over the roadway corresponding to the location of the vehicle. The presence or strength of the magnetic field provided on the roadway may be dependent upon the vehicle type or category.

Abstract: A circuit for energizing a magnetic flux coupling apparatus has a pick-up coil for receiving power inductively, a storage capacitor for storing energy from the received power, and an inverter for supplying electrical energy from the storage capacitor to the magnetic flux coupling apparatus. The circuit allows power transfer to a load to be supplied by the flux coupling apparatus to exceed the power received from the pick-up.

Abstract: A magnetic structure for wireless power transfer has a plurality of pieces of magnetically permeable material arranged along a first dimension. Each piece is separated from a neighbouring piece by a gap defining a separation distance which is selected to prevent partial saturation of a region of the structure.

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: The present invention provides a multi-coil inductive power transfer primary comprising a plurality of coil. A power transfer regime is selected based on a determined load on each of the plurality of coils.

Abstract: A method of detecting a wirelessly powered vehicle on a roadway uses detection of induced voltages or currents in coils provided in the roadway. Once the vehicle has been detected the appropriate coils can be energised to power the vehicle.

Abstract: A method of charging a battery includes coupling an electricity network or subnetwork to the battery using inductive power transfer, transferring electrical energy to the battery from the electricity network or subnetwork and varying the inductive power transfer using a controller of the electricity network or subnetwork according to at least one predetermined criteria of the electricity network or subnetwork.

Abstract: A method of detecting a wirelessly powered vehicle on a roadway uses detection of induced voltages or currents in coils provided in the roadway. Once the vehicle has been detected the appropriate coils can be energised to power the vehicle.

Abstract: An inductive charging apparatus includes a primary conductor with at least one node for creating a magnetic field and at least one intermediate resonant circuit including a first coil for receiving inductive power from the node, a second coil operable in use to be driven by current from the first coil to generate a magnetic field for power transfer, and a tuning capacitor coupled to the first and second coils for resonance therewith.

Abstract: A method of charging a battery includes coupling an electricity network or subnetwork to the battery using inductive power transfer, transferring electrical energy to the battery from the electricity network or subnetwork and varying the inductive power transfer using a controller of the electricity network or subnetwork according to at least one predetermined criteria of the electricity network or subnetwork.

Abstract: Disclosed herein is an inductive power transfer (IPT) compensation circuit and method for reflecting a controlled reactance to a primary conductor at a selected operating frequency, compensating for reactive loads reflected to the primary conductor by one or more other pick-ups inductively coupled with the primary conductor in use. The compensation circuit comprises a first switch means coupled to a resonant circuit and operable to reflect a capacitive reactance to the primary conductor; a second switch means coupled to the resonant circuit and operable to reflect an inductive reactance to the primary conductor; and control means adapted to control operation of the first and second switch means to compensate for inductive and capacitive reactances, respectively, in the primary conductor.

Abstract: A wireless coupling structure has a first layer comprising a flux coupling coil having two opposing end regions separated by two opposing side regions; a second layer comprising a first block of ferrite and a second block of ferrite; and a third layer comprising a leakage flux control coil. The first block is provided next to one of the end regions and the second block is provided next to the other of the end regions.

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 track arrangement including a power supply and conductor electrically connected to the power supply, the conductor includes a plurality of loops located substantially adjacent one another, wherein the polarity in adjacent portions of the loops is the same, and wherein the power supply includes a one or more inverters which share the track load.