Abstract: This application provides a direct current contactor which includes a housing, and a first fixed contact and a second fixed contact that are fastened into the housing; a first moving contact and a second moving contact that are located in the housing; a drive mechanism, including: an insulation rod connected to the first moving contact and the second moving contact, and a drive component that drives the insulation rod to drive the first moving contact and the second moving contact to synchronously move toward the first fixed contact and the second fixed contact; and a pressing component configured to push the moving contact firmly against the fixed contact. Only two pairs of contacts are used to implement connection/disconnection of two electrode lines, so that a total contactor resistance is reduced by half compared with that in the conventional technology.

Abstract: A powertrain includes a motor, a reducer, an oil pan, and a cooling system. The cooling system includes at least one heat exchanger and at least two oil pumps. The at least two oil pumps are configured to deliver, to the heat exchanger, cooling oil sucked from the oil pan. The heat exchanger is configured to cool the cooling oil sucked by the at least two oil pumps. An oil outlet port of the heat exchanger is connected to an oil passage in the motor and an oil passage in the reducer, so that a part of the cooling oil cools the motor through the oil passage in the motor, and another part of the cooling oil cools the reducer through the oil passage in the reducer. The embodiments can improve a cooling effect of the cooling system for the powertrain.

Abstract: A photovoltaic converter and a photovoltaic generation system. The photovoltaic converter is configured to electrically connect to a first photovoltaic module and a second photovoltaic module, where the first photovoltaic module includes a first positive electrode output end and a first negative electrode output end, and the second photovoltaic module includes a second positive electrode output end and a second negative electrode output end. The photovoltaic converter includes a current transformer and a power conversion circuit. The current transformer includes a magnetic structure, a first positive primary side winding, a second positive primary side winding, a negative primary side winding, and a first secondary side winding. The three primary side windings all pass through the magnetic structure and are spaced from each other. The first secondary side winding is wound around the magnetic structure. This reduces an occupied board area.

Abstract: A power converter includes a first conversion circuit and a control apparatus connected to the first conversion circuit. The control apparatus detects an output voltage of the first conversion circuit to obtain a voltage value of a first voltage, and generates a slope compensation signal based on the voltage value of the first voltage. The control apparatus obtains an error signal based on an error between the voltage value of the first voltage and a voltage value of a reference voltage, and compares the slope compensation signal with the error signal to obtain a comparison signal. The control apparatus then generates a drive signal of the first conversion circuit based on the comparison signal.

Abstract: A common mode choke includes a toroidal magnetic core and N windings wound on the toroidal magnetic core. The N windings are rotationally symmetric in a central direction of the toroidal magnetic core. Each of the N windings includes two lead ends which are respectively located at outermost layers of two sides of each winding. Each of the N windings includes a first group of windings and a second group of windings. A starting point of each of the N windings is located between the first group of windings and the second group of windings. A quantity of winding sections in the first group of windings is different from a quantity of winding sections in the second group of windings. Each winding section in both the first group of windings and the second group of windings includes a plurality of winding layers. Each winding layer includes a plurality of coils.

Abstract: A battery management system includes a sampling control unit, a DC/DC conversion unit, and an energy storage unit. When the battery pack needs to be heated, based on battery parameters of the battery pack and a voltage and a current limit value of the DC/DC conversion unit, the sampling control unit may control, in each of at least one consecutive first cycle, the battery pack to discharge to the energy storage unit by using the DC/DC conversion unit; control, in each of at least one consecutive second cycle, the energy storage unit to charge the battery pack by using the DC/DC conversion unit; and control, in the at least one consecutive first cycle and the at least one consecutive second cycle, an average charge/discharge current value of the battery pack to be less than or equal to a charge/discharge current limit value.

Abstract: An energy storage and charging station. Heat of an energy storage system and heat of a charging system are managed in a centralized manner so that the energy storage system and the charging system can exchange heat by using a heat exchange assembly. A cooling medium in a cooling medium loop separately flows through the charging system and the energy storage system, and the charging system and the energy storage system each exchange heat with the cooling medium loop. Heat generated when the charging system works is transferred, through the cooling medium loop, to the energy storage system for use, to reduce energy consumption required to heat the energy storage system to maintain a temperature, and improve energy use efficiency.

Abstract: A converter for avoiding a short-circuit fault of the converter while inhibiting a surge impact includes: a power factor correction (PFC) circuit, a surge protection circuit, and a switch circuit. The PFC circuit is configured to: convert a first component of a first alternating current received by an alternating current terminal of the PFC circuit into a first direct current, and output the first direct current through a direct current terminal of the PFC circuit; and convert a second direct current received by the direct current terminal of the PFC circuit into a second alternating current, and output the second alternating current through the alternating current terminal of the PFC circuit.

Abstract: This application provides a wireless power transmission system. The system includes a transmitter and a receiver, where the transmitter includes a DC/AC inverter circuit, a first resonant inductor, a first capacitor, and a first compensation inductor that are connected in series; and the receiver includes an AC/DC rectifier circuit, a second resonant inductor, a second capacitor, and a second compensation inductor that are connected in series; and power at the transmitter is transmitted to the receiver through electromagnetic induction between the first resonant inductor and the second resonant inductor, and the AC/DC rectifier circuit is configured to provide the rectified power to a load of the receiver. This solution is applicable to a wireless power supply scenario or a wireless charging scenario.

Abstract: Embodiments of this application provide a power system. An output terminal of a power supply or a DC-to-DC unit is cascaded. In addition, according to the power system provided in embodiments of this application, a quantity of cables from the power supply or the DC-to-DC unit to the DC-to-AC unit may be further reduced by cascading an output terminal of the power supply or the DC-to-DC unit and cascading an input of the DC-to-AC unit.

Abstract: A charging and discharging apparatus and a vehicle, to reduce complexity of a structural layout of the vehicle and improve integration of the vehicle. The charging and discharging apparatus includes: an AC/DC conversion circuit configured to convert an input first alternating current into a first direct current; a DC/DC conversion circuit configured to rectify the first direct current to output a second direct current used to charge a power battery and a third direct current used to charge a low-voltage battery; a DC/AC conversion circuit configured to convert a fourth direct current output by the power battery into a second alternating current used to supply power to a power-consuming device; and a controller configured to control output voltages and/or output currents of the AC/DC conversion circuit, the DC/DC conversion circuit, and the DC/AC conversion circuit.

Abstract: A power supply system and a grid connection control method. The power supply system includes a power supply, an inverter, a transformer, a power station collection module, and an inverter collection control circuit. The inverter collection control circuit is configured to obtain an amplitude value and a frequency of an output voltage of the inverter, obtain an inverter power adjustment signal based on the amplitude value and the frequency of the output voltage, and control, based on the power station power adjustment signal and the inverter power adjustment signal, the inverter to output a target output power. Additionally, an output power of the inverter may be adjusted by using the power station collection module and the inverter collection control circuit. A structure is simple, and a control method is simple. This improves control precision and adjustment efficiency, reduces control time, and reduces control costs.

Abstract: This application discloses a wireless charging receiver and a wireless charging method. The method includes: receiving, by using a first oscillation circuit, pulse energy emitted by a transmitter, where the first oscillation circuit includes a first receiving coil configured to convert the pulse energy and output power; when a voltage value output by the first oscillation circuit reaches a first reference voltage value, sending a power transfer instruction to the transmitter, so that the transmitter emits energy according to the power transfer instruction, where the first reference voltage value is a working voltage threshold of a processor; and receiving, by using a second oscillation circuit, the energy emitted by the transmitter according to the power transfer instruction.

Abstract: A power supply apparatus includes a switching circuit including a switcher, a first input terminal, a second input terminal, and an output terminal, the first input terminal is configured to receive a first voltage provided by a first power supply, the second input terminal is configured to receive a second voltage provided by a second power supply, and the switcher is configured to control the output terminal to be connected to the first input terminal or control the output terminal to be connected to the second input terminal; and a converting circuit including an input terminal connected to the output terminal of the switching circuit, an output terminal connected to an electrical device, and the converting circuit is configured to receive the first or the second voltage, convert the received first second voltage into a third voltage, and output the third voltage through the output terminal of the converting circuit.

Abstract: An electric drive system is connected to a power battery pack to drive a motor, the motor includes an exciting winding, and the electric drive system includes a bus, a three-level inverter circuit, an electric excitation circuit, and a controller. The bus includes a positive bus and a negative bus. The three-level inverter circuit includes a first bus capacitor and a second bus capacitor. The first bus capacitor is connected between the positive bus and a bus midpoint, and the second bus capacitor is connected between the negative bus and the bus midpoint. A first input terminal of the electric excitation circuit is connected in parallel to the first bus capacitor, a second input terminal of the electric excitation circuit is connected in parallel to the second bus capacitor, and an output terminal of the electric excitation circuit is connected to the exciting winding of the motor.

Abstract: A power conversion circuit includes a controller, a first-level DC/DC conversion circuit, a plurality of second-level DC/DC conversion circuits, a switching module, a first capacitor, a plurality of second capacitors, and a battery. When a voltage of the battery is less than a first voltage threshold and voltages of the first capacitor and the second capacitor are less than a third voltage threshold, the controller controls the switching module to be turned off or turned on, so that the plurality of second-level DC/DC conversion circuits are connected in series; or when the voltage of the battery is greater than a second voltage threshold and voltages at two ends of the first capacitor and the second capacitor are less than the third voltage threshold, the controller controls the switching module to be turned off or turned on, so that the plurality of second-level DC/DC conversion circuits are connected in parallel.

Abstract: A vehicle-mounted power supply apparatus and a vehicle. The vehicle-mounted power supply apparatus includes a power conversion circuit, an upper-layer PCB board, a lower-layer PCB board, a bottom cover, and a radiator. The upper-layer PCB board and the lower-layer PCB board are configured to bear a plurality of power switching transistors of the power conversion circuit, so that the power conversion circuit is distributed more flexibly. The lower-layer PCB board and a plurality of transformers are fastened to a bottom plate of the bottom cover, and cooled by heat dissipation through a lower-layer cooling channel in the bottom cover. The upper-layer PCB board and the radiator are sequentially stacked above the lower-layer PCB board and the plurality of transformers, and cooled by heat dissipation through an upper-layer cooling channel in the radiator.

Abstract: A semiconductor device includes a channel layer and a barrier layer that are sequentially stacked, a doped layer, and a gate structure. The channel layer and the barrier layer each are made of a group III nitride material. The barrier layer includes a gate region. The doped layer is located on a side of the barrier layer that is away from the channel layer. The doped layer is located in the gate region. A material of the doped layer is a group III-V compound including a receptor-type doped element.

Abstract: A power conversion device includes a power conversion device includes an auxiliary power supply, a first load, a power conversion circuit, and a controller. When an output voltage of the auxiliary power supply in operation is greater than or equal to a first voltage threshold, the controller controls the first load to be connected to the power conversion device, so that the output voltage of the auxiliary power supply decreases. When the output voltage of the auxiliary power supply is greater than or equal to a second voltage threshold after the first load is connected to the power conversion device, the controller controls the first load to be disconnected from the power conversion device, and controls the output voltage of the auxiliary power supply to be a first target output voltage. The first voltage threshold is less than the second voltage threshold.

Abstract: Embodiments of this application provide a centrifugal pump. The centrifugal pump includes a pump casing and a first drive mechanism, a second drive mechanism, a pump shaft, and an impeller that are disposed in the pump casing. The pump casing includes a first chamber and a second chamber that are connected. An axis of the pump shaft coincides with axes of the first chamber and the second chamber. An inner diameter of the second chamber is greater than that of the first chamber. The impeller is connected to an end of the pump shaft. The first drive mechanism and the second drive mechanism are connected to the pump shaft and located on a side, away from the impeller, of the pump shaft. The first drive mechanism is configured to drive the pump shaft to rotate.