Abstract: Example wireless charging systems and methods are disclosed. One example system includes a receive end and a transmit end. The receive end includes a receive coil, a receive end compensation circuit, a rectifier, and a controller. The controller adjusts a phase difference between a first bridge arm and a second bridge arm of the rectifier, and adjusts a phase-shift angle between a bridge arm voltage of the rectifier and a fundamental component of an input current of the rectifier, so that zero-voltage switching is implemented for controllable switching transistors of the rectifier. An inductance compensation module may weaken a capacitive part of the equivalent impedance, and reduce reactive power of the wireless charging system.

Abstract: An apparatus and a method for detecting a metal foreign matter in a wireless charging system, and a device are provided. The apparatus includes a phase-lock control module, an excitation module, a resonance module, a signal collection module, and a determining module. The phase-lock control module is configured to: adjust a frequency of a first signal and output the first signal to the excitation module and the determining module. The excitation module is configured to: generate a second signal based on the first signal, and output the second signal to the resonance module. The resonance module is configured to output the third signal to the signal collection module under excitation of the second signal. The determining module is configured to determine whether there is a metal foreign matter in an area of the target coil.

Abstract: The technology of this application relates to a foreign object detection apparatus that includes a controller, a first resonant network, a signal coupler, and a phase difference detector. The signal coupler may obtain a resonance current signal corresponding to the first resonant network, and couple the resonance current signal to a preset carrier signal to obtain a coupled current signal. A frequency of the preset carrier signal can be the same as a frequency of an excitation signal. The phase difference detector may extract a low-frequency signal component from the coupled current signal, and determine a phase difference signal based on the low-frequency signal component. An amplitude of the phase difference signal correspondingly indicates a phase difference between the excitation signal and the resonance current signal. The controller may determine, based on the amplitude of the phase difference signal, whether a foreign object exists in a detection area corresponding to the first resonant network.

Abstract: A resonant power supply, a primary-side feedback excitation power supply controller, a method, and a control apparatus are disclosed. In the resonant power supply, a bridge circuit is electrically connected to a power supply. The bridge circuit is configured to convert, based on a drive signal, a direct current provided by the power supply into a square wave signal. An LC series resonant network is electrically connected to the bridge circuit and a primary-side winding. The LC series resonant network is configured to convert the square wave signal into an alternating current, and output the alternating current to the primary-side winding. The alternating current includes an input voltage Vt and an input current Ir.

Abstract: An inverter current equalization method includes separately comparing a reactive current of a first inverter and a reactive current of a second inverter with a reactive current reference value, to obtain a reactive current difference of the first inverter and a reactive current difference of the second inverter, separately comparing an active current of the first inverter and an active current of the second inverter with an active current reference value, to obtain an active current difference of the first inverter and an active current difference of the second inverter, and adjusting an input voltage amplitude of the first inverter and an input voltage amplitude of the second inverter based on the reactive current difference of the first inverter and the reactive current difference of the second inverter.

Abstract: Example positioning system based on a low frequency magnetic field and apparatus are described. One example positioning system includes a low frequency magnetic field transmit apparatus and a low frequency magnetic field receive apparatus. The transmit apparatus includes a transmit coil, a conflict detect coil, and a magnetic field generation detection control module. The receive apparatus includes a receive coil and a magnetic field detection control module. When the conflict detect coil does not sense a low frequency magnetic field signal, the magnetic field generation detection control module controls the transmit coil to transmit a first low frequency magnetic field signal. When the received low frequency magnetic field signal is the first low frequency magnetic field signal, the magnetic field detection control module determines relative positions of the transmit coil and the receive coil based on signal strength of the first low frequency magnetic field signal.

Abstract: This application discloses a wireless charging receiver, transmitter, system, and control method, and an electric vehicle, and relates to the field of wireless charging technologies. A low-frequency magnetic field receive coil of the receiver converts a low-frequency magnetic field into an induced signal. A receiver controller is configured to: when all low-frequency magnetic field transmit coils stop working, allocate a signal feature different from that of a current induced signal to each low-frequency magnetic field transmit coil, and send a correspondence between each low-frequency magnetic field transmit coil and the allocated signal feature to the wireless charging transmitter; and is further configured to determine, when the low-frequency magnetic field transmit coil works, relative positions of the power transmit coil and the power receive coil by using an induced signal having the allocated signal feature.

Abstract: A transmit end, a receive end, a method, and a system for wireless charging are provided, and are applied to the field of electric vehicles. A transmit-end controller compares an actual output current of an inverter with a preset upper limit value of an output current of the inverter and controls an output voltage of the inverter based on a comparison result to adjust a current of a transmit coil. A receive-end controller receives a sampled value of the current of the transmit coil that is sent by the transmit-end controller and updates a reference value of the current of the transmit coil when a difference between the sampled value of the current of the transmit coil and the reference value of the current of the transmit coil is greater than or equal to a preset value.

Abstract: This application discloses a phase alignment circuit and method of a receive end, and a receive end, where the phase alignment circuit and method of a receive end. The receive end is located on the electric vehicle. The circuit includes: a phase measurement circuit and a controller. The controller is configured to: use, as an actual phase shift angle, a result obtained by subtracting the phase difference from a preset phase shift angle, and control a phase of a bridge arm voltage of the rectifier to lag behind the phase of the input current fundamental component by the actual phase shift angle. The controller outputs a drive signal for a controllable switching transistor of the rectifier by using the actual phase shift angle. Because a lagging phase caused due to filtering is compensated for, precision of synchronization between the bridge arm voltage and the input current can be increased.

Abstract: This application provides a frequency locking method, a wireless charging system, a receiving device, and a transmitting device for determining, through interaction between the receiving device and the transmitting device in a wireless charging scenario, whether a frequency locking procedure can be performed between the transmitting device and the receiving device. The receiving device includes: a controller, configured to control short-circuiting of an input terminal of a rectifier; a transceiver, configured to transmit a frequency locking request to the transmitting device, where the frequency locking request carries information about a first preset range, and the frequency locking request requests the transmitting device to generate an emission current whose frequency is within the first preset range; a receiving module, configured to obtain an input current of the rectifier based on the emission current; and a detector, configured to detect a frequency of the input current.

Abstract: A wireless charging receive end, system, and control method, and relates to the field of wireless charging technologies is provided. The wireless charging receive end includes a receiver coil, a compensation network, a power converter, and a receive end controller. The receiver coil converts an alternating magnetic field transmitted by a transmit end into an alternating current and transmits the alternating current to the compensation network. The compensation network compensates for the alternating current and then transmit a compensated alternating current to the power converter. The power converter rectifies the compensated alternating current into a direct current for charging a load. The receive end controller obtains a reference signal at the transmit end based on an input current of the power converter and an input reference current, and sends the reference signal at the transmit end to a transmit end controller.

Abstract: A wireless charging receiver, system, and control method, and relates to the field of wireless charging technologies are disclosed. A receiver coil of the receiver converts an alternating magnetic field transmitted by a transmitter to an alternating current, and delivers the alternating current to a compensation network. The compensation network compensates the alternating current, and then delivers the compensated alternating current to a rectifier. The rectifier rectifies the compensated alternating current to a direct current, and supplies the direct current to a load. The compensation network is a compensation circuit with a current source characteristic, so that the receiver coil and the compensation network, acting together with the transmitter, make an input end of the rectifier a constant current source.

Abstract: A wireless charging transmitting apparatus and method and a wireless charging system are provided. The transmitting apparatus includes a compensation circuit (206), an inverter circuit (201), a transmitting coil (202), an impedance adjustment circuit (203), and a controller (204). The impedance adjustment circuit (203) includes a leading-bridge-arm impedance adjustment circuit and a lagging-bridge-arm impedance adjustment circuit, and the leading-bridge-arm impedance adjustment circuit and the lagging-bridge-arm impedance adjustment circuit each include an inductive branch, where the inductive branch includes at least one controllable inductive branch, and each controllable inductive branch includes at least one inductor and at least one switch. The controller (204) controls the switches in the controllable inductive branches to be turned on or off, to adjust values of inductive currents injected into a leading bridge arm and a lagging bridge arm through the impedance adjustment circuit (203).

Abstract: The technology of this disclosure relates to a wireless charging alignment method and apparatus, a wireless charging system, and an electric vehicle, and belongs to the field of wireless charging. In the wireless charging alignment apparatus, a first detection circuit may detect a first induction signal of a power receive coil in a positioning magnetic field generated by a power transmit coil; a second detection circuit may detect a second induction signal of a location detection coil in the positioning magnetic field; and a location determining circuit may determine a location of the power receive coil relative to the power transmit coil based on the first induction signal and the second induction signal.

Abstract: This application discloses wireless charging apparatuses, methods, and systems. One apparatus includes: a direct current to alternating current (DC-to-AC) inverter circuit configured to invert a DC output by a DC power supply to an AC; a compensation circuit configured to compensate the AC output by the DC-to-AC inverter circuit and send the AC obtained after the compensation to a transmitting coil; the transmitting coil configured to receive the AC and generate an AC magnetic field; an impedance adjustment circuit comprising one or more inductive branches; and a controller configured to control on or off of the switch in the inductive branch to change a current flowing out of the lagging bridge arm to enable a controllable switching transistor of the lagging bridge arm to implement zero-voltage switching.

Abstract: A receive end and a transmit end of a wireless charging system, and the wireless charging system, where the receive end includes a receive coil, a rectifier, and a receive end controller, where the receive coil receives an alternating magnetic field and outputs an alternating current, the rectifier is configured to rectify the alternating current from the receive coil into a direct current, the receive end controller is configured to adjust, based on a target impedance sent by a transmit end controller, a reflection impedance reflected from the receive end to a transmit end such that an inverter of the transmit end implements a zero voltage switching (ZVS), and a bridge arm voltage is a voltage between two bridge arm midpoints of a full bridge rectifier or a voltage between a single bridge arm midpoint of a half bridge rectifier and ground.

Abstract: This application discloses a phase alignment circuit and method of a receive end, and a receive end, where the phase alignment circuit and method of a receive end. The receive end is located on the electric vehicle. The circuit includes: a phase measurement circuit and a controller. The controller is configured to: use, as an actual phase shift angle, a result obtained by subtracting the phase difference from a preset phase shift angle, and control a phase of a bridge arm voltage of the rectifier to lag behind the phase of the input current fundamental component by the actual phase shift angle. The controller outputs a drive signal for a controllable switching transistor of the rectifier by using the actual phase shift angle. Because a lagging phase caused due to filtering is compensated for, precision of synchronization between the bridge arm voltage and the input current can be increased.

Abstract: A wireless charging receiving apparatus is provided, which includes a receiver coil, a rectifier, and a controller. The receiver coil is configured to receive electromagnetic energy and output an alternating current. The rectifier includes at least two controllable switches, and is configured to rectify the alternating current from the receiver coil to a direct current s. The controller is configured to perform phase-locking on a phase of a current fundamental component of the alternating current received by the rectifier, to obtain a periodic signal having a same frequency as the current fundamental component; and the controller is further configured to: generate a synchronization reference signal having the same frequency as the periodic signal, generate drive signals of the controllable switches in the rectifier based on the synchronization reference signal, and control, based on the drive signals, controllable switches in the rectifier to convert the alternating current into the direct current.

Abstract: Example wireless charging systems and methods are disclosed. One example system includes a receive end and a transmit end. The receive end includes a receive coil, a receive end compensation circuit, a rectifier, and a controller. The controller adjusts a phase difference between a first bridge arm and a second bridge arm of the rectifier, and adjusts a phase-shift angle between a bridge arm voltage of the rectifier and a fundamental component of an input current of the rectifier, so that zero-voltage switching is implemented for controllable switching transistors of the rectifier. An inductance compensation module may weaken a capacitive part of the equivalent impedance, and reduce reactive power of the wireless charging system.

Abstract: This application discloses a phase alignment circuit and a method of a receive end, and a receive end. The receive end is located on an electric vehicle. The phase alignment circuit includes a phase measurement circuit and a controller. The controller is configured to: use, as an actual phase shift angle, a result obtained by subtracting a phase difference from a preset phase shift angle, and control a phase of a bridge arm voltage of a rectifier to lag behind the phase of the input current fundamental component by the actual phase shift angle. The controller outputs a drive signal for a controllable switching transistor of the rectifier by using the actual phase shift angle. Because a lagging phase caused due to filtering is compensated for, precision of synchronization between the bridge arm voltage and the input current can be increased.