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 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: Systems and methods are described that reduce magnetic flux density proximate to a wireless charging pad, such as a WEVC pad. These systems and methods control peak magnetic flux density in air around a WEVC pad to reduce potentially dangerous heat produced in foreign metal objects affected by a magnetic field generated by a coil of the WEVC pad. Controlling the peak magnetic flux density results in a safer WEVC pad. Aspects include ferrite tiles being separated by gaps having predefined sizes to increase a magnetic reluctance of a path of the magnetic flux through the ferrite tiles, which reduces a peak magnetic flux density experienced in areas proximate to the coil. In addition, the ferrite tiles can be arranged such that a combination of gaps are aligned with a region overlapping the coil.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for multi-phase coil control in power transfer systems. One example power transfer device generally includes a plurality of coils configured to generate at least one charging field, the plurality of coils comprising a first coil and a second coil, and a controller configured to identify that a coupling factor between the first coil and a third coil, which is external to the power transfer device, is at or below a threshold, and to adjust, based on the identification, one or more parameters associated with a current applied to the first coil to transfer power from the first coil to the second coil.

Abstract: A magnetic flux coupler comprising a magnetically permeable core having a first axis, two coils magnetically associated with the core, each coil defining a pole area located on a first side of the core and the pole areas being separated along the first axis, the coils each having a central region located between the pole areas, an end region opposite to the central region, and a side region between the central region and the end region, wherein an auxiliary pole area is provided beyond the end region of each coil which absorbs leakage flux which would otherwise emanate from the each coil in use in the vicinity of the end region.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for multi-phase coil control in power transfer systems. One example power transfer device generally includes a plurality of coils configured to generate at least one charging field, the plurality of coils comprising a first coil and a second coil, and a controller configured to identify that a coupling factor between the first coil and a third coil, which is external to the power transfer device, is at or below a threshold, and to adjust, based on the identification, one or more parameters associated with a current applied to the first coil to transfer power from the first coil to the second coil.

Abstract: Systems and methods are described for a ferrite arrangement that mitigates dimensional-tolerance effects on performance of a wireless charging pad, such as a WEVC pad. These systems and methods include a power-transfer structure having ferrite bars arranged to form ferrite strips in a staggered pattern to provide a path for magnetic flux induced by a magnetic field. The staggered pattern includes a series of ferrite strips that alternate defined starting-point locations at opposing sides of the power-transfer structure. Ending-point locations of the ferrite strips are not defined, but are based on an accumulation of lengthwise dimensional tolerances of the ferrite bars used to form the ferrite strips. Using the staggered pattern in a base power-transfer structure defines a coupling range for coupling with a vehicle power-transfer structure and a range limit for associated magnetic field emissions by the base power-transfer structure.

Abstract: An (PT 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 magnetic flux pad for receiving or generating magnetic flux. The pad includes two pole areas (11, 12) associated with a magnetically permeable core 14. Coils 17 define the pole areas. The pad allows useable flux to be generated at a significant height above a surface of the pad.

Abstract: A multiphase IPT primary track conductor arrangement comprising a first phase conductor and a second phase conductor, the conductors being arranged substantially in a plane and so as to overlap each other and being arranged such that there is substantially balanced mutual coupling between the phase conductors.

Abstract: In certain aspects, methods and systems for reducing magnetic field emissions from double-D inductive couplers are disclosed. Certain aspects of the present disclosure provide a power transfer device for reducing magnetic field emissions. The power transfer device generally includes a first coil and a second coil configured to generate a charging field; and at least one auxiliary coil coupled in series with at least one of the first coil or the second coil, the at least one auxiliary coil being configured to reduce magnetic field emission of the charging field.

Abstract: An apparatus for transmitting charging power wirelessly to a vehicle is provided. The apparatus comprises a first coupler having a first reactance at an operating frequency and configured to wirelessly receive power from a power source, the first coupler wound on a ferromagnetic core. The apparatus comprises a first capacitor having a second reactance at the operating frequency and electrically connected in series with the first coupler, the second reactance having a magnitude equal to a magnitude of the first reactance. The apparatus comprises a second capacitor electrically connected in parallel across the first coupler and the first capacitor. The apparatus comprises a first base coupler configured to be electrically connected in parallel across the second capacitor via a first switch. A magnitude of a peak voltage across the second capacitor is proportional to a magnitude of a peak voltage induced in the first coupler at the operating frequency.

Abstract: A magnetic flux pad (BPP) is provided for receiving magnetic flux. The pad may be used with an inductive power transfer system, and comprises a magnetically permeable core (4) and two substantially flat overlapping coils (2, 3) magnetically associated with the core (4).

Abstract: A method of operating a wireless-power receiver comprises: determining a first resonant frequency of a resonant circuit, of the wireless-power receiver, corresponding to a first time at which the wireless-power receiver is disposed at a first longitudinal offset from a power transmitter, the first longitudinal offset being relative to a length of a device containing the wireless-power receiver; determining a second resonant frequency of the resonant circuit, corresponding to a second time at which the wireless-power receiver is disposed at a second longitudinal offset from the power transmitter, the second longitudinal offset being relative to the length of the device containing the wireless-power receiver, and the first longitudinal offset being different from the second longitudinal offset; and determining a lateral misalignment of the wireless-power receiver relative to a wireless-power transmitter based on the first resonant frequency and the second resonant frequency.

Abstract: According to some implementations, an apparatus for transmitting charging power wirelessly to a load is provided. The apparatus comprises at least one ferrite structure comprising a first ferrite portion, a second ferrite portion comprising at least a first ferrite leg, a second ferrite leg, and a third ferrite leg, each physically separated from the first ferrite portion by a first distance, and a third ferrite portion positioned between the second ferrite leg and the first ferrite portion and physically contacting the second ferrite leg. The at least one ferrite structure further comprises a coil wound around the second ferrite leg and configured to generate an alternating current under influence of an alternating magnetic field.

Abstract: Aspects of this disclosure include an apparatus configured to and methods for the transfer of wireless power. The apparatus comprises a first coil enclosing a first area. The apparatus also comprises a second coil enclosing a second area different than the first area, the second coil positioned to be at least partially coplanar with the first coil. The apparatus further comprises a ferrite material and a third coil and a fourth coil each wound about the ferrite material, the third coil at least partially enclosed by the first coil and the fourth coil at least partially enclosed by the second coil.

Abstract: An apparatus for wirelessly transferring charging power is provided. The apparatus comprises a first coil, as second coil, a ferrite structure positioned on one side of the first coil and the second coil. The ferrite structure includes a first angled surface at an outer side of the first coil and a second angled surface at an outer side of the second coil. The ferrite structure further includes a substantially flat surface at an inner side of the first coil and an inner side of the second coil. The first angled surface and the second angled surface are at an angle to the flat surface.

Abstract: Systems and methods are described that increase pad efficiency and robustness. These systems and methods balance magnetic flux density in ferrite strips in a WEVC pad to reduce heat produced in high-flux areas of the ferrite strips. Aspects include controlled spacing between ferrite strips of a WEVC pad and intentional gaps located within high-flux areas in the strips. The sizes of the intentional gaps are determined in relation to the size of the spacing between the strips. In addition, ribs are disposed between the strips and connected to a backplate to provide structural rigidity and robustness to the pad.

Abstract: The present disclosure describes aspects of a vehicle-based beacon mode for wireless electric vehicle charging. In some aspects, a circuit for receiving wirelessly transferred power includes a coil connected to boost circuitry configured to convert received power to a form suitable for storage. The circuit also includes beacon circuitry connected to a voltage source that, in combination with portions of the boost circuitry, enables current to be driven into the coil to generate a beacon signal. Based on this beacon signal, a base charging unit can detect the presence of the circuit and initiate the wireless transmission of power to the circuit without additional out-of-band communication. Further, the beacon circuitry may be compatible with, or protected from, current of the received power such that the circuit can seamlessly transition from generating the beacon signal to converting the received power without active reconfiguration, synchronization, or state control.

Abstract: Systems and methods are described for a ferrite arrangement that mitigates dimensional-tolerance effects on performance of a wireless charging pad, such as a WEVC pad. These systems and methods include a power-transfer structure having ferrite bars arranged to form ferrite strips in a staggered pattern to provide a path for magnetic flux induced by a magnetic field. The staggered pattern includes a series of ferrite strips that alternate defined starting-point locations at opposing sides of the power-transfer structure. Ending-point locations of the ferrite strips are not defined, but are based on an accumulation of lengthwise dimensional tolerances of the ferrite bars used to form the ferrite strips. Using the staggered pattern in a base power-transfer structure defines a coupling range for coupling with a vehicle power-transfer structure and a range limit for associated magnetic field emissions by the base power-transfer structure.