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 are generally directed to apparatus for attenuating unwanted frequencies using a feed line with integrated filtering. In certain aspects, a feed line for filtering unwanted frequencies in a wireless power transfer system is provided, the feed line including a first end, wherein the first end is configured to connect to a power source that generates a driving signal having a driving signal frequency, and a second end, wherein the second end is configured to connect to a wireless power transfer element configured to wirelessly transmit power. The feed line further includes a conductor core, wherein the conductor core is configured to transfer the driving signal from the power source to the wireless transfer element. The feed line further includes an integrated filter configured to attenuate at least one frequency generated by the wireless power transfer system.

Abstract: Certain aspects of the present disclosure are generally directed to apparatus for attenuating unwanted frequencies using a feed line with integrated filtering. In certain aspects, a feed line for filtering unwanted frequencies in a wireless power transfer system is provided, the feed line including a first end, wherein the first end is configured to connect to a power source that generates a driving signal having a driving signal frequency, and a second end, wherein the second end is configured to connect to a wireless power transfer element configured to wirelessly transmit power. The feed line further includes a conductor core, wherein the conductor core is configured to transfer the driving signal from the power source to the wireless transfer element. The feed line further includes an integrated filter configured to attenuate at least one frequency generated by the wireless power transfer system.

Abstract: An apparatus for designing, tuning and matching of wireless power transfer systems comprises a processor. The processor is configured to determine electrical circuit parameters of a wireless power transfer system for each combination of a plurality of characteristics for the wireless power transfer system that are within respective ranges for each of the plurality of characteristics. The processor is configured to select a first group of combinations of the plurality of characteristics for which the electrical circuit parameters determined satisfy a set of user design constraints. The processor is configured to validate a second group of combinations selected from the first group of combinations that satisfy a performance requirement of the wireless power transfer system.

Abstract: Techniques for detecting a presence of a metallic and/or a ferromagnetic object over a region for wirelessly transferring power to charge an electric vehicle are presented. An example apparatus includes one or more foreign object detection (FOD) loops arranged in an array over a charging area, at least a portion of the FOD loops being in a first configuration and at least a portion of the FOD loops being second configuration different than the first configuration based on a value indicative of an amount of magnetic coupling between the charging area and a respective one the FOD loops within a corresponding area of the array.

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: This disclosure includes systems, methods and apparatus for reducing emissions for polarized coil systems for wireless inductive power transfer. In one aspect, a magnetic flux device is provided which includes at least a first electrically conductive coil and a second electrically conductive coil that is substantially coplanar with the first coil. The device includes a magnetically permeable material having a substantially planar surface. The first coil and the second coil are substantially parallel to the substantially planar surface. The area of the material extends beyond the area of the first coil and beyond the area of the second coil. The area of the coil can substantially surround the area of the first coil and the area of the second coil.

Abstract: Techniques for determining power electronics feasibility in a wireless power transfer system with a transmitting element and a receiving element are provided. An example apparatus includes a processor configured to receive FEM simulation results for offset positions between the transmitting element and the receiving element, calculate a total real input current variation for the offset positions based on the FEM simulation results, calculate an indication of a difference between an ideal transmitting element current value and a real transmitting element current value for each of the offset positions based on the FEM simulation results, determine a maximum difference value based on the indication of the difference for each of the offset positions, and determine the power electronics feasibility based on the total real input current variation as compared to a total real input current variation threshold value, and the maximum difference value as compared to a maximum difference threshold value.

Abstract: One innovation includes a system for reducing magnetic flux of a wireless charging field in a wireless power charging system. The system comprises a wireless power transmitter configured to generate the wireless charging field, the field comprising the magnetic flux and a collector comprising a ferromagnetic material and configured to reduce the magnetic flux. The collector is positioned between a first distance and a second distance at a third distance from the transmitter. The collector is configured to reduce the magnetic flux at a first level at the first distance, at a second level at the second distance, and at a third level at the third distance, the third level greater than each of the first and second levels.

Abstract: Techniques for detecting a presence of a metallic and/or a ferromagnetic object over a region for wirelessly transferring power to charge an electric vehicle are presented. An example apparatus includes one or more foreign object detection (FOD) loops arranged in an array over a charging area, at least a portion of the FOD loops being in a first configuration and at least a portion of the FOD loops being second configuration different than the first configuration based on a value indicative of an amount of magnetic coupling between the charging area and a respective one the FOD loops within a corresponding area of the array.

Abstract: A method and apparatus for reducing leakage magnetic flux in wireless vehicle charging systems are disclosed. A wireless power receiver may be configured to couple to a wireless field generated by a wireless power transmitter. A portion of the wireless field may comprise the leakage magnetic flux. A leakage collector comprising a ferromagnetic material may be positioned at a distance from the wireless power receiver within the wireless field and may be configured to absorb or redirect at least a portion of the leakage magnetic flux away from an outer edge of an electric vehicle.

Abstract: This disclosure provides systems, methods and apparatus for avoiding magnetic power loss while providing alternating current through a ferromagnetic material. In one aspect, the ferromagnetic material includes at least one orifice. At least one electrical conduit extends through the at least one orifice from a first region on a first side of the ferromagnetic material to a second region on a second side of the ferromagnetic material, the second side opposite to the first side. The at least one electrical conduit is configured to have at least one alternating current flowing along the at least one electrical conduit between the first region and the second region. The ferromagnetic material and the at least one electrical conduit are configured to reduce power loss caused by a circumferential magnetic flux generated within the ferromagnetic material by the at least one alternating current.

Abstract: One innovation includes a system for reducing magnetic flux of a wireless charging field in a wireless power charging system. The system comprises a wireless power transmitter configured to generate the wireless charging field, the field comprising the magnetic flux and a collector comprising a ferromagnetic material and configured to reduce the magnetic flux. The collector is positioned between a first distance and a second distance at a third distance from the transmitter. The collector is configured to reduce the magnetic flux at a first level at the first distance, at a second level at the second distance, and at a third level at the third distance, the third level greater than each of the first and second levels.

Abstract: An apparatus for designing, tuning and matching of wireless power transfer systems comprises a processor. The processor is configured to determine electrical circuit parameters of a wireless power transfer system for each combination of a plurality of characteristics for the wireless power transfer system that are within respective ranges for each of the plurality of characteristics. The processor is configured to select a first group of combinations of the plurality of characteristics for which the electrical circuit parameters determined satisfy a set of user design constraints. The processor is configured to validate a second group of combinations selected from the first group of combinations that satisfy a performance requirement of the wireless power transfer system.

Abstract: A method and apparatus for reducing leakage magnetic flux in wireless vehicle charging systems are disclosed. A wireless power receiver may be configured to couple to a wireless field generated by a wireless power transmitter. A portion of the wireless field may comprise the leakage magnetic flux. A leakage collector comprising a ferromagnetic material may be positioned at a distance from the wireless power receiver within the wireless field and may be configured to absorb or redirect at least a portion of the leakage magnetic flux away from an outer edge of an electric vehicle.

Abstract: This disclosure includes systems, methods and apparatus for reducing emissions for polarized coil systems for wireless inductive power transfer. In one aspect, a magnetic flux device is provided which includes at least a first electrically conductive coil and a second electrically conductive coil that is substantially coplanar with the first coil. The device includes a magnetically permeable material having a substantially planar surface. The first coil and the second coil are substantially parallel to the substantially planar surface. The area of the material extends beyond the area of the first coil and beyond the area of the second coil. The area of the coil can substantially surround the area of the first coil and the area of the second coil.

Abstract: This disclosure provides systems, methods and apparatus for avoiding magnetic power loss while providing alternating current through a ferromagnetic material. In one aspect, the ferromagnetic material includes at least one orifice. At least one electrical conduit extends through the at least one orifice from a first region on a first side of the ferromagnetic material to a second region on a second side of the ferromagnetic material, the second side opposite to the first side. The at least one electrical conduit is configured to have at least one alternating current flowing along the at least one electrical conduit between the first region and the second region. The ferromagnetic material and the at least one electrical conduit are configured to reduce power loss caused by a circumferential magnetic flux generated within the ferromagnetic material by the at least one alternating current.