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: This application provides a wireless charger and a control method. The wireless charger includes a class-E power amplifier and a tunable impedance circuit that is connected to an output end of the class-E power amplifier. The class-E power amplifier includes a switching transistor and a tunable capacitance circuit that is parallelly connected to the switching transistor. The wireless charger further includes a control unit, configured to obtain a constraint condition of the class-E power amplifier; determine N1 target equivalent load impedances of the class-E power amplifier based on the constraint condition; and adjust a capacitance value of the tunable capacitance circuit in the class-E power amplifier, and adjust an impedance value of the tunable impedance circuit, to enable an equivalent load impedance of the class-E power amplifier to match one of the N1 target equivalent load impedances.

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: 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: 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: 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.

Abstract: A wireless charging control method for an electric vehicle or a wireless charging transmitter includes an inner-loop control circuit, a boost circuit, an inverter circuit, and a transmitting coil, where the inner-loop control circuit is coupled to both the boost circuit and the inverter circuit, and an input end and an output end of the inverter circuit are respectively coupled to the boost circuit and the transmitting coil, and the inner-loop control circuit is configured to obtain a first current reference signal and a sampled current signal of the transmitting coil, compare the first current reference signal with the sampled current signal to obtain an absolute value of a difference between the first current reference signal and the sampled current signal, and adjust a phase shift angle of the inverter circuit or a duty cycle of the boost circuit when the absolute value is greater than a preset deviation.

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.

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 provides a wireless charger and a control method. The wireless charger includes a class-E power amplifier and a tunable impedance circuit that is connected to an output end of the class-E power amplifier. The class-E power amplifier includes a switching transistor and a tunable capacitance circuit that is parallelly connected to the switching transistor. The wireless charger further includes a control unit, configured to obtain a constraint condition of the class-E power amplifier; determine N1 target equivalent load impedances of the class-E power amplifier based on the constraint condition; and adjust a capacitance value of the tunable capacitance circuit in the class-E power amplifier, and adjust an impedance value of the tunable impedance circuit, to enable an equivalent load impedance of the class-E power amplifier to match one of the N1 target equivalent load impedances.

Abstract: A service control method and a service control apparatus, where the method includes obtaining, a current electricity grid electricity price and a quantity of to-be-executed services, determining an electricity price threshold according to the quantity of the to-be-executed services, decreasing, by the service control apparatus, a quantity of services that are about to be executed by a first quantity when the current electricity grid electricity price is greater than the electricity price threshold, and executing a service according to a reduced quantity of services that are about to be executed, or increasing, by the service control apparatus, a quantity of services that are about to be executed by a second quantity, and executing a service according to an increased quantity of services that are about to be executed when the current electricity grid electricity price is less than the electricity price threshold.

Abstract: A service control method and a service control apparatus, where the method includes obtaining, a current electricity grid electricity price and a quantity of to-be-executed services, determining an electricity price threshold according to the quantity of the to-be-executed services, decreasing, by the service control apparatus, a quantity of services that are about to be executed by a first quantity when the current electricity grid electricity price is greater than the electricity price threshold, and executing a service according to a reduced quantity of services that are about to be executed, or increasing, by the service control apparatus, a quantity of services that are about to be executed by a second quantity, and executing a service according to an increased quantity of services that are about to be executed when the current electricity grid electricity price is less than the electricity price threshold.

Abstract: A method for detecting a battery state of health includes a current and a voltage are measured twice in a period of time; corresponding model algorithms are selected according to the measured current values; corresponding battery open circuit voltage values and battery state of charge values at a start time and an end time of the period are obtained based on the model algorithms; a battery capacity difference that indicates a present battery retention capacity and a battery capacity difference that indicates a future battery retention capacity are calculated; and a battery state of health value is calculated when impact of a measured battery temperature value is considered.

Abstract: A service control method and a service control apparatus, where the method includes obtaining, a current electricity grid electricity price and a quantity of to-be-executed services, determining an electricity price threshold according to the quantity of the to-be-executed services, decreasing, by the service control apparatus, a quantity of services that are about to be executed by a first quantity when the current electricity grid electricity price is greater than the electricity price threshold, and executing a service according to a reduced quantity of services that are about to be executed, or increasing, by the service control apparatus, a quantity of services that are about to be executed by a second quantity, and executing a service according to an increased quantity of services that are about to be executed when the current electricity grid electricity price is less than the electricity price threshold.

Abstract: A method for detecting a battery state of health includes a current and a voltage are measured twice in a period of time; corresponding model algorithms are selected according to the measured current values; corresponding battery open circuit voltage values and battery state of charge values at a start time and an end time of the period are obtained based on the model algorithms; a battery capacity difference that indicates a present battery retention capacity and a battery capacity difference that indicates a future battery retention capacity are calculated; and a battery state of health value is calculated when impact of a measured battery temperature value is considered.