Abstract: A charge/discharge circuit includes a power supply module, a switch module, an energy storage module, and a charge-discharge switching module connected in parallel. A first terminal of the energy storage module is connected to the switch module, and a second terminal of the energy storage module is connected to the charge-discharge switching module. The switch module and the charge-discharge switching module are configured to perform an action in response to a charge/discharge enable signal to produce an alternating current in the charge/discharge circuit. A waveform of the alternating current includes at least one of a triangular waveform, a quasi-triangular waveform, a sinusoidal waveform, or a quasi-sinusoidal waveform.

Abstract: This application provides a permanent-magnet synchronous machine control method and device, and a permanent-magnet synchronous machine control system. The method includes: obtaining a d-axis current id and a q-axis current iq in a permanent-magnet synchronous machine control loop at a current moment; obtaining a fifth-order harmonic current id5th and a seventh-order harmonic current id7th in the d-axis current id in the permanent-magnet synchronous machine control loop at the current moment, and a fifth-order harmonic current iq5th and a seventh-order harmonic current iq7th in the q-axis current iq in the permanent-magnet synchronous machine loop at the current moment; determining a d-axis current idk+1 at a next moment in each switch state; determining a q-axis current iqk+1 at the next moment in each switch state based on the first current idk, the second current iqk, and the second voltage in each switch state; and determining a control policy of the permanent-magnet synchronous machine.

Abstract: Provided are a battery heating device and a control method and circuit therefor, and a power device. The battery heating device includes: a heating module including a first bridge arm, a second bridge arm, and an energy storage element; and a control module configured to control the first bridge arm and the second bridge arm, to form a circuit for discharging from a first battery cell to the energy storage element and a circuit for charging from the energy storage element and the first battery cell to a second battery cell, and/or to form a circuit for discharging from the second battery cell to the energy storage element and a circuit for charging from the energy storage element and the second battery cell to the first battery cell, for heating of the first battery cell and the second battery cell.

Abstract: An energy storage system includes a first energy storage branch and a second energy storage branch connected in parallel. The first energy storage branch includes a first battery cluster. The second energy storage branch includes a second battery cluster and a DC/DC converter connected to the second battery cluster in series, with an output end of the DC/DC converter being connected to the second battery cluster. The DC/DC converter is configured to adjust an output current of the second energy storage branch to balance an output current of the first energy storage branch and the output current of the second energy storage branch.

Abstract: A battery charging control method applicable to a vehicle electrical system that includes a current control unit including a semiconductor device. Two ends of the current control unit are connected to a battery and a charging power supply, respectively. The method includes controlling, when a temperature of the battery is below a preset temperature, the current control unit to be in a first state in which the semiconductor device is reversely connected in a circuit, sending a first charging request including a first charging current required to heat the battery to the preset temperature, controlling, when the temperature of the battery reaches the preset temperature, the current control unit to be in a second state in which the semiconductor device is disconnected from the circuit or forwardly connected in the circuit, and sending a second charging request including a second charging current at which the battery is charged.

Abstract: This application provides an electric motor control method and device, a system, and an electric vehicle. The method includes: obtaining an input power and an output power of an electric motor; calculating a loss power based on the input power and the output power; determining a target d-axis current of the electric motor, where the target d-axis current is calculated by a calculation module based on the loss power, the calculation module includes a tracking differentiator, and the calculation module operates in a controller; and determining a duty ratio based on the target d-axis current and a preset q-axis current, and inputting the duty ratio into an inverter so that the inverter drives, based on the duty ratio, the electric motor to operate.

Abstract: The embodiments of the present disclosure provide a control method, a device, a power system, and an electric vehicle. The method is applied to a motor controller of the power system. The power system further includes a power battery, a motor, and an inverter. The method includes: sending a first control signal to the inverter when a cell temperature of the power battery satisfies a preset heating condition for the power battery; where the first control signal is configured to control the inverter to convert an electricity provided by the power battery into an alternating current with a frequency changing randomly, and the alternating current with the frequency changing randomly is configured to supply power to the motor.

Abstract: This application provides a permanent-magnet synchronous machine control method and device, and a permanent-magnet synchronous machine control system. The method includes: obtaining a d-axis current id and a q-axis current iq in a permanent-magnet synchronous machine control loop at a current moment; obtaining a fifth-order harmonic current id5th and a seventh-order harmonic current id7th in the d-axis current id in the permanent-magnet synchronous machine control loop at the current moment, and a fifth-order harmonic current iq5th and a seventh-order harmonic current iq7th in the q-axis current iq in the permanent-magnet synchronous machine loop at the current moment; determining a d-axis current idk+1 at a next moment in each switch state; determining a q-axis current iqk+1 at the next moment in each switch state based on the first current idk, the second current iqk, and the second voltage in each switch state; and determining a control policy of the permanent-magnet synchronous machine.

Abstract: This application provides a method and device for updating calibration data of an electric motor, an electronic device, and a storage medium. The method includes: obtaining an initial calibration datum of the electric motor; determining whether a deviation between the initial calibration datum and a theoretical calculation datum exceeds a first threshold; recalibrating the electric motor based on the preset calibration parameter when the deviation between the initial calibration datum and the theoretical calculation datum exceeds the first threshold, and obtaining an updated calibration datum; determining whether a deviation between the updated calibration datum and the initial calibration datum exceeds a second threshold; and updating the initial calibration datum based on the updated calibration datum when the deviation between the updated calibration datum and the initial calibration datum does not exceed the second threshold, thereby updating and rectifying the initial calibration datum.

Abstract: This application provides an electric motor control method and device, a system, and an electric vehicle. The method includes: obtaining an input power and an output power of an electric motor; calculating a loss power based on the input power and the output power; determining a target d-axis current of the electric motor, where the target d-axis current is calculated by a calculation module based on the loss power, the calculation module includes a tracking differentiator, and the calculation module operates in a controller; and determining a duty ratio based on the target d-axis current and a preset q-axis current, and inputting the duty ratio into an inverter so that the inverter drives, based on the duty ratio, the electric motor to operate.

Abstract: Embodiments of this application provide a torque obtaining method and device, a motor controller, and a readable storage medium. The torque obtaining method includes: obtaining a rotation speed of a motor; obtaining a current of the motor; obtaining a flux linkage of the motor; determining an electromagnetic torque of the motor based on the current and the flux linkage; and inputting the rotation speed and the electromagnetic torque into a preset status observer, and obtaining an observed value of an actual output torque of the motor, where the observed value is output by the status observer. The obtaining method is intended to obtain the actual output torque effectively, simply, and accurately.

Abstract: The present application provide a control method of a power battery heating system. The method includes: controlling all upper bridge arms of a first bridge arm group and all lower bridge arms of a second bridge arm group to be turned on, and all lower bridge arms of the first bridge arm group and all upper bridge arms of the second bridge arm group to be turned off, so as to form a first loop; controlling all the lower bridge arms of the first bridge arm group and all the upper bridge arms of the second bridge arm group to be turned on, and all the upper bridge arms of the first bridge arm group and all the lower bridge arms of the second bridge arm group to be turned off, so as to form a second loop. The method is used to heat the power battery.

Abstract: The present application provides a control method, an apparatus, a power system, and an electric vehicle, relating to the field of electric vehicles. The method includes: obtaining a battery cell temperature of a power battery, and sending a first control signal to an inverter when the battery cell temperature meets a preset power battery heating condition, where the first control signal is configured to control the inverter to convert a current provided by the power battery into an alternating current with a randomly changing frequency, and the alternating current with a randomly changing frequency is configured to supply power to a permanent magnet motor. New frequency components may be introduced to evenly distribute originally concentrated radial electromagnetic forces to an entire stator, thereby reducing vibration noises during the heating process of the power battery.

Abstract: The present application provides a control method, an apparatus, a power system, and an electric vehicle, relating to the field of electric vehicles. The method includes: obtaining a battery cell temperature of a power battery, and sending a first control signal to an inverter when the battery cell temperature meets a preset power battery heating condition, where the first control signal is configured to control the inverter to convert a current provided by the power battery into an alternating current with a randomly changing frequency, and the alternating current with a randomly changing frequency is configured to supply power to a permanent magnet motor. New frequency components may be introduced to evenly distribute originally concentrated radial electromagnetic forces to an entire stator, thereby reducing vibration noises during the heating process of the power battery.