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: In a battery heating system an inverter includes a first-phase bridge arm, a second-phase bridge arm and a third-phase bridge arm connected in parallel, each of a upper bridge arm and a lower bridge arm is provided with a switch module, the switch module is connected in parallel with a buffer module; and a motor controller in the inverter is provided for providing driving signals to the switch module of a target upper bridge arm and the switch module of a target lower bridge arm to control the switch module of the upper bridge arm of any bridge arm among the three phases of bridge arms and the switch module of the lower bridge arm of at least one bridge arm among the bridge arms except the bridge arm where the switch module of the target upper bridge arm is located to be periodically turned on and off.

Abstract: The disclosure provides a thermal runaway detection circuit and method, and relates to batteries. The thermal runaway detection circuit includes: a sensing module including a sensing cable; a detection module connected to the sensing cable and including at least one set of voltage dividing resistors; a processing module connected to the detection module, wherein the processing module is configured to obtain thermal runaway detection data, and determine whether thermal runaway occurs in the battery pack based on the thermal runaway detection data, wherein the thermal runaway detection data includes battery pack data and sampled data collected from sampling points, and the sampling points are disposed between the two connected voltage dividing resistor sets. The technical solutions in the present disclosure can improve safety of the battery pack.

Abstract: The embodiments of the present application provide a current modulation module, a parameter determination module, a battery heating system, as well as a control method and a control device thereof, and relate to the field of battery. The control method includes determining a state of charge (SOC), of the battery, modulating a first current flowing into windings of a motor into an alternating current when the SOC is greater than a first SOC threshold, so as to use heat generated by the alternating current in a first target module to heat the battery, and modulating a second current flowing into the windings of the motor into a direct current when the SOC is less than or equal to the first SOC threshold, so as to use heat generated by the direct current in a second target module to heat the battery.

Abstract: The application provides a control system and method for a battery pack heating system. The control system includes: a battery management system configured to acquire a state parameter of a battery pack, and send heating request information to a vehicle controller when determining the state parameter of the battery pack meets a preset heating condition; a motor controller configured to send, to the vehicle controller, feedback information indicating that a motor of the battery pack heating system is in a non-operating state, when determining the motor is in the non-operating state, and control, in response to a first control signal, a target upper bridge arm switch module and a target lower bridge arm switch module to be periodically turned on or off; and the vehicle controller configured to send the first control signal to the motor controller in response to the heating request information and the feedback information.

Abstract: A measurement device includes: a host computer and a current source, wherein the host computer is configured to: control, when ambient temperature of a current detection device is at a preset temperature within an operation temperature range of a shunt of the current detection device, the current source to output a current with a preset current value to the current detection device; receive a calibrated current value sent by the current detection device; calculate a measurement error of the current detection device according to the preset current value and the calibrated current value; and instruct, when the measurement error is less than a preset current error, the current detection device to use the predetermined current calibration coefficient as a current calibration coefficient.

Abstract: The present disclosure provides a battery management system and a communication method. The method includes: determining, by a main BMU, from a plurality of managed units a fault unit that communicates abnormally with the main BMU, and transmitting, by the main BMU, to a backup BMU a fault frequency at which the fault unit communicates abnormally with the main BMU; selecting, by the backup BMU, from the managed units a managed unit that communicates normally with the backup BMU and the fault unit as a target unit; transmitting, by the backup BMU, frequency-conversion information to the fault unit through the target unit based on the fault frequency; converting, by the fault unit, its frequency to a frequency; transmitting the frequency to the main BMU if the backup BMU communicates normally with the fault unit using the frequency; and communicating, by the main BMU, with the fault unit using the frequency.

Abstract: The embodiments of the present application provide a low-voltage power transmission system, a DCDC converter and a control method, a device and a medium, relating to the field of battery power. The control method includes: acquiring a charging signal; acquiring a vehicle start signal; acquiring an enabling signal; when each of the charging signal, the vehicle activating start signal, and the enabling signal is at a low level, and no communication message sent by a battery management system (BMS) is received, determining that a vehicle is in a power-off state and enters a sleep mode; when a duration of the sleep mode reaches a preset duration, performing self-awakening, and outputting, to the BMS, an awakening signal for awakening the BMS and making the BMS enter a working mode.

Abstract: This application discloses a power supply guarantee system and method. The power supply guarantee system is applied to a battery management system. The power supply guarantee system includes: a main control module, configured to send a received wake-up time to a timing device; a high voltage power module, configured to power the timing device according to electrical energy in a high voltage battery pack; the timing device, configured to set a wake-up clock according to the wake-up time, start timing when the BMS enters sleep, and send a discharge instruction to the high voltage battery pack when the timing reaches the wake-up time; and a power conversion module, configured to convert high voltage electrical energy into low voltage electrical energy, and use the low voltage electrical energy to power the BMS, where the high voltage electrical energy is output by the high voltage battery pack according to the discharge instruction.

Abstract: The present disclosure provides a heating control method and a heating control device. The heating control method includes: acquiring an average current value in a heating circuit of a power battery pack; calculating a current output value required for nth cycle according to an average current value of the nth cycle, an average current value of (n?1)th cycle, an average current value of (n?2)th cycle, a preset current value, n is equal to or greater than 3; outputting a PWM signal to a switch device of the heating circuit according to a pre-calibrated PWM control parameter corresponding to the current output value so that a difference between an actual current value in the heating circuit and the preset current value is less than a preset threshold.

Abstract: A method and an apparatus for controlling a permanent magnet motor, a power system and an electric vehicle. A power frequency of the permanent magnet motor is set by obtaining system parameters such as a resonance bandwidth of the permanent magnet motor and a natural frequency of a stator of the permanent magnet motor, and the permanent magnet motor is supplied power by using alternating current at the power frequency when a power battery meets a self-heating condition. Noises generated by the motor is reduced during a self-heating process of the power battery.

Abstract: The present application discloses a system and method for providing a constant power source. The system includes: a main control module configured to receive a wake-up time and send the wake-up time to a timer device; a timer power supply module configured to supply power to the timer device according to electric energy in a high-voltage battery pack; a high-voltage power supply module configured to supply power to a power conversion module according to the electric energy in the high-voltage battery pack; the timer device configured to set a wake-up clock according to the wake-up time, start timing when a battery management system (BMS) enters into sleep, and send a discharge instruction to the high-voltage battery pack when the timing reaches the wake-up time; the power conversion module configured to convert high-voltage electric energy output from the high-voltage battery pack into low-voltage electric energy and supply power to the BMS.

Abstract: The present disclosure provides a control device, an energy conversion system, an energy conversion method and a storage medium. The control device includes: a detection unit configured to detect a first voltage between a positive electrode of the energy storage device and a first end of an energy conversion device, a second voltage between a negative electrode of the energy storage device and a second end of the energy conversion device, and a third voltage between the positive electrode and the negative electrode of the energy storage device; a processing unit configured to calculate a resistance value corresponding to the energy conversion device according to the first voltage, the second voltage, and the third voltage; when the value of resistance is greater than a resistance threshold value, controlling the energy storage device to supply power to the electrical equipment through the energy conversion device.

Abstract: The present disclosure discloses a current sampling method and a current sampling circuit. The method comprises: obtaining a detected temperature of each semiconductor switch device of a plurality of parallel semiconductor switch devices; determining that the plurality of parallel semiconductor switch devices are in a current equalization state based on the detected temperature of each semiconductor switch device; obtaining an equalized current flowing through a target semiconductor switch device in the current equalization state, the target semiconductor switch device being any one of the plurality of parallel semiconductor switch devices; determining a total current of a main circuit connected to the plurality of parallel semiconductor switch devices according to the equalized current.

Abstract: A method and an apparatus for controlling a permanent magnet motor, a power system and an electric vehicle. A power frequency of the permanent magnet motor is set by obtaining system parameters such as a resonance bandwidth of the permanent magnet motor and a natural frequency of a stator of the permanent magnet motor, and the permanent magnet motor is supplied power by using alternating current at the power frequency when a power battery meets a self-heating condition. Noises generated by the motor is reduced during a self-heating process of the power battery.

Abstract: The present application provides an insulation detection circuit, a method and a battery management system. The circuit includes: a first voltage dividing module, where, one end of the first voltage dividing module is connected to a positive electrode of a power battery to be detected, and the other end of the first voltage dividing module is connected to a first isolation module and a second voltage dividing module respectively; the second voltage dividing module, connected to a negative electrode of the power battery to be detected; the first isolation module, connected to one end of a sampling module; the sampling module, where, the other end of the sampling module is connected to one end of a signal generating module; the signal generating module, where, the other end of the signal generating module is connected to power ground; and the processing module.

Abstract: The application provides a method for controlling a power converter, in which a theoretical output voltage of a first converter is acquired according to a voltage of a source side, a theoretical input voltage of a second converter is acquired according to a voltage of a destination side, and an actual output voltage of the first converter in a first power supply cycle is set according to the theoretical output voltage of the first converter and the theoretical input voltage of the second converter.

Abstract: The battery management system comprises: a battery management unit, configured to receive status information of a battery module and status information of a battery pack, and transmit a control instruction to cell measurement circuits; the cell measurement circuits, configured to collect the status information of the battery module, transmit the status information of the battery module to the battery management unit, receive and execute the control instruction transmitted from the battery management unit; sensing units, configured to collect the status information of the battery pack, and transmit the status information of the battery pack to the battery management unit; wherein a wireless communication unit is disposed in the battery management unit, and a wireless communication unit is disposed in at least a portion of the cell measurement circuits and/or at least a portion of the sensing units.

Abstract: Provided is a method and device for obtaining internal side and external side insulation resistances of a relay. The method includes: controlling an insulation resistance obtaining circuit to output an AC signal; when both a main relay and a pre-charge relay are switched off, obtaining a first phase shift of the AC signal between two sampling points according to first collected electrical signals; obtaining an internal side insulation resistance of the main relay according to the first collected electrical signals and the first phase shift; controlling the pre-charge relay to be switched on; when the main relay is switched off and the pre-charge relay is switched on, obtaining a second phase shift of the AC signal between the two sampling points according to second collected electrical signals; and obtaining an external side insulation resistance of the main relay according to the second collected electrical signals and the second phase shift.

Abstract: This application provides a method and an apparatus for controlling a grid-tie inverter. The method includes: acquiring an output voltage of the grid-tie inverter and an output current value of the grid-tie inverter at a current moment; calculating N output current values of the grid-tie inverter at a next moment that is in one-to-one correspondence to N switch states of the grid-tie inverter based on the output current value at the current moment, and N is a natural number greater than or equal to 2; acquiring a first reference current based on the output voltage; acquiring a second reference current based on the output current and the first reference current; determining a first switch state; and controlling the grid-tie inverter to perform power transmission in the first switch state at the next moment.