Abstract: This disclosure provides systems, methods and apparatuses for preventing power transfer in a secondary coil of a wireless power reception apparatus. Some implementations relate generally to the use of one or more switches. In some implementations, the one or more switches may be coupled in series to one or both ends of the secondary coil. The one or more switches may be controlled based on a handshake communication between the wireless power reception apparatus and a compatible wireless power transmission apparatus. The one or more switches may be controlled using bias power from a wireless communication interface that is separate from a power reception circuitry that includes the secondary coil. The one or more switches may disable power transfer in the secondary coil to protect one or more components of the wireless power reception apparatus or to enable measurement of a coupling factor during measurement periods.

Abstract: This disclosure provides systems, methods and apparatuses for foreign object detection (FOD) in a wireless power transfer (WPT) system. Some implementations relate generally to the use of detection coils that are excited to measure and compare a differential current through a coil pair that includes at least two detection coils. A foreign object may cause a change in impedance for one or more detection coils compared to one or more other detection coils. By detecting the differential current of the coil pair, a detection apparatus may determine that a foreign object is in proximity to one of the detection coils of the coil pair. This disclosure provides several options for the design, construction, layout, and operations of detection coils to improve foreign object detection.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for wireless power transmission. In accordance with this disclosure, a wireless power transmission apparatus (such as a charging pad) may support positional freedom such that a wireless power receiving apparatus may be charged regardless of positioning or orientation of the wireless power receiving apparatus. Various implementations include the use of multiple primary coils in a wireless power transmission apparatus. The multiple primary coils may be configured in a pattern, size, shape, or arrangement that enhances positional freedom. In some implementations, the placement of the multiple primary coils may optimize the size and distribution of electromagnetic fields that are available to charge a wireless power receiving apparatus.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for a wireless power transmission apparatus that supports charging of one or more wireless power receiving apparatuses. The wireless power transmission apparatus may include multiple primary coils organized in groups (referred to as zones). Each zone may have a local controller for managing operation of one primary coil in the zone at a time. A master controller may selectively couple the primary coils to the local controllers. When a first primary coil is coupled to the local controller for a zone, the other primary coils in that zone may be disabled. The master controller may manage which primary coils from neighboring zones are coupled to their respective local controllers. Thus, when the first primary coil is activated, the adjacent primary coils (near the first primary coil) can be muted or disabled to mitigate undesirable interference.

Abstract: This disclosure provides systems, methods and apparatuses for foreign object detection (FOD) in a wireless power transfer (WPT) system. Some implementations relate generally to the use of detection coils that are excited to measure and compare a differential current through a coil pair that includes at least two detection coils. A foreign object may cause a change in impedance for one or more detection coils compared to one or more other detection coils. By detecting the differential current of the coil pair, a detection apparatus may determine that a foreign object is in proximity to one of the detection coils of the coil pair. This disclosure provides several options for the design, construction, layout, and operations of detection coils to improve foreign object detection.

Abstract: This disclosure provides systems, methods and apparatuses for foreign object detection (FOD) in a wireless power transfer (WPT) system. Some implementations relate generally to the use of detection coils that are excited to measure and compare a differential current through a coil pair that includes at least two detection coils. A foreign object may cause a change in impedance for one or more detection coils compared to one or more other detection coils. By detecting the differential current of the coil pair, a detection apparatus may determine that a foreign object is in proximity to one of the detection coils of the coil pair. This disclosure provides several options for the design, construction, layout, and operations of detection coils to improve foreign object detection.

Abstract: This disclosure provides systems, methods, and apparatuses for wireless power reception. Various implementations relate generally to a wireless power reception apparatus including multiple secondary coils that receive wireless power from corresponding primary coils of a wireless power transmission apparatus. When a secondary coil receives power form a primary coil, they form a latched coil pair. Initially, the wireless power reception apparatus receives via a number of latched coil pairs. Coil pairs may de-latch as they physically move out of alignment. If one or more coil pairs de-latch, voltage may drop in the latched coil pairs. The wireless power reception apparatus includes a power controller that can detect drops in voltage resulting from de-latching coil pairs. In response, the power controller can modify current drawn from the remaining latched coil pairs. By modifying current drawn from the remaining latched coil pairs, the power controller can avoid system failure.

Abstract: This disclosure provides systems, methods and apparatuses for wireless power transmission and reception. A wireless power transmission apparatus may include a primary coil that transmits power to a corresponding secondary coil in a wireless power reception apparatus. The wireless power transmission apparatus may configure characteristics of the wireless power transmission based on a load setting of a wireless power reception apparatus. The wireless power transmission apparatus may take into account a coupling factor and power transfer characteristics of the wireless power reception apparatus in determining a configuration of the wireless power transmission from the wireless power transmission apparatus to the wireless power reception apparatus. In some implementations, a change in wireless power transmission may occur based on a corresponding change in the load. For example, the change in wireless power transmission and the corresponding change in the load may occur in relation to a synchronization event.

Abstract: The present application relates to a method for controlling a power system connected to a power grid, including: receiving a reactive power instruction and a measured reactive power from a generator; generating a reactive power error signal based on the difference between the reactive power instruction and the measured reactive power; receiving the reactive power error signal; generating a voltage instruction based on reactive power error signal; generating a voltage droop signal based on a reference reactance and a voltage at a point of common coupling; generating a voltage error signal according to at least one of the voltage instruction or the measured terminal voltage of the generator and the voltage droop signal; and producing a reactive current instruction for the converter power path based on the voltage error signal. The present application also discloses a control system for a power system connected to a power grid and a wind farm.

Abstract: The present application relates to a method for controlling a power system connected to a power grid, including: receiving a reactive power instruction and a measured reactive power from a generator; generating a reactive power error signal based on the difference between the reactive power instruction and the measured reactive power; receiving the reactive power error signal; generating a voltage instruction based on reactive power error signal; generating a voltage droop signal based on a reference reactance and a voltage at a point of common coupling; generating a voltage error signal according to at least one of the voltage instruction or the measured terminal voltage of the generator and the voltage droop signal; and producing a reactive current instruction for the converter power path based on the voltage error signal. The present application also discloses a control system for a power system connected to a power grid and a wind farm.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for wireless power transmission. A wireless power transmission apparatus may transmit multiple wireless power signals to a wireless power reception apparatus configured to combine the power from the multiple wireless power signals. The wireless power reception apparatus may provide a combined wireless power signal to a load such as a battery charger or electronic device. In some implementations, each set of primary coil and secondary coil may utilize low power wireless power signals (such as 15 Watts or less) in accordance with a wireless charging standard. By combining power from multiple low power wireless power signals, the wireless power reception apparatus may support higher power requirements of an electronic device. Multiple communication channels may be established between the wireless power transmission apparatus and the wireless power reception apparatus.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for wireless power transmission. A wireless power receiving apparatus may be configured to combine power from multiple wireless power signals. In some implementations, the wireless power receiving apparatus may combine wireless power received from multiple secondary coils to provide a combined wireless power signal to a load, such as a battery charger or electronic device. In some implementations, each set of primary coil and secondary coil may utilize low power wireless power signals (such as 15 Watts or less) in accordance with a wireless charging standard. By combining power from multiple low power wireless power signals, the wireless power receiving apparatus may support higher power requirements of an electronic device. The disclosed designs may minimize electromagnetic interference (EMI) and provide greater efficiency of wireless power transfer.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for a wireless power transmission apparatus that supports charging of one or more wireless power receiving apparatuses. The wireless power transmission apparatus (such as a charging pad or surface) may include multiple primary coils and multiple local controllers (such as one local controller per primary coil). Each local controller can independently activate a primary coil to supply power to a wireless power receiving apparatus. Thus, the wireless power transmission apparatus may support concurrent charging of multiple wireless power receiving apparatuses. When a first primary coil is activated, a local controller can mute or disable the adjacent primary coils (near the first primary coil) to mitigate undesirable interference.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for a wireless power transmission apparatus that supports charging of one or more wireless power receiving apparatuses. The wireless power transmission apparatus may include multiple primary coils organized in groups (referred to as zones). Each zone may have a local controller for managing operation of one primary coil in the zone at a time. A master controller may selectively couple the primary coils to the local controllers. When a first primary coil is coupled to the local controller for a zone, the other primary coils in that zone may be disabled. The master controller may manage which primary coils from neighboring zones are coupled to their respective local controllers. Thus, when the first primary coil is activated, the adjacent primary coils (near the first primary coil) can be muted or disabled to mitigate undesirable interference.

Abstract: One innovative aspect of the subject matter described in this disclosure can be implemented in a wireless power reception apparatus. In some implementations, the wireless power reception apparatus may include a ferrite layer including a void. The wireless power reception apparatus may also include a first secondary coil configured to generate first power in cooperation with one or more primary coils of a wireless power transmission apparatus, where at least a portion of the first secondary coil resides in the void of the ferrite layer. The wireless power reception apparatus may also include one or more second secondary coils configured to generate second power in cooperation with the one or more primary coils of the wireless power transmission apparatus, where a portion of the second secondary coil is overlaying the portion of the first secondary coil residing in the void of the ferrite layer.

Abstract: Power systems and circuitry for generation of gradient magnetic fields in magnetic resonance imaging (MRI) systems are discussed herein. Embodiments may include the use of multiple gradient amplifiers that share a high-frequency power distribution unit, that may perform power distribution and power supply roles. The high-frequency power distribution unit may allow the use of a single power supply to drive multiple gradient amplifiers via a shared power bus. The gradient amplifiers may make use of modern semiconductor materials that provide high-frequency, high voltage performance, and may be implemented using single semiconductor bridges.

Abstract: This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for wireless power transmission. In accordance with this disclosure, a wireless power transmission apparatus (such as a charging pad) may support positional freedom such that a wireless power receiving apparatus may be charged regardless of positioning or orientation of the wireless power receiving apparatus. Various implementations include the use of multiple primary coils in a wireless power transmission apparatus. The multiple primary coils may be configured in a pattern, size, shape, or arrangement that enhances positional freedom. In some implementations, the placement of the multiple primary coils may optimize the size and distribution of electromagnetic fields that are available to charge a wireless power receiving apparatus.

Abstract: Power systems and circuitry for generation of gradient magnetic fields in magnetic resonance imaging (MRI) systems are discussed herein. Embodiments may include the use of multiple gradient amplifiers that share a high-frequency power distribution unit, that may perform power distribution and power supply roles. The high-frequency power distribution unit may allow the use of a single power supply to drive multiple gradient amplifiers via a shared power bus. The gradient amplifiers may make use of modern semiconductor materials that provide high-frequency, high voltage performance, and may be implemented using single semiconductor bridges.