Direct current charging device, power assembly and electric vehicle

Abstract

The application provides a direct-current charging device, a power assembly and an electric vehicle. The direct-current charging device is used for charging a power battery of the electric vehicle. The direct-current charging device comprises a direct-current charging interface, a switching module and a direct-current voltage conversion module. The direct-current charging interface is used for connecting positive and negative poles of a power supply device and positive and negative poles of the power battery to form a charging loop. The switching module is used for turning on or turning off the charging loop. The direct-current voltage conversion module is used for outputting a preset direct-current voltage to the positive and negative poles of the power supply device. The direct-current charging device, the power assembly and the electric vehicle provided by the application can restore the charging without requiring the user to re-scan the card / code again after the power battery of the electric vehicle is disconnected from the charging loop of the charging pile, thereby reducing the user operation and improving the user experience.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and more particularly to a DC charging device, a powertrain, and an electric vehicle. Background Technology

[0002] With the development of new energy vehicle technology, many car manufacturers have gradually launched electric vehicles. Electric vehicles have become the choice of many users due to their energy saving, environmental protection and relatively mature technology.

[0003] After an electric vehicle (EV) connects to a charging station, the user typically needs to swipe a card / scan a code. The charging station then charges the EV through a charging circuit between the EV's battery and the station. For user safety, the EV can only charge in non-operating mode. When the EV's battery is charging, the charging circuit between the battery and the charging station is disconnected, and the charging station will usually stop charging. Once the charging circuit is reconnected, the user usually needs to swipe their card / scan the code again to resume charging. Summary of the Invention

[0004] This application provides a DC charging device, a powertrain, and an electric vehicle. After the electric vehicle's power battery is disconnected from the charging circuit of the charging pile, it can be reconnected without the user having to swipe a card / scan a code again to resume charging, reducing user operations and thus improving the user experience.

[0005] In a first aspect, embodiments of this application provide a DC charging device. The DC charging device is used to charge the power battery of an electric vehicle, and includes a DC charging interface, a switching module, and a DC voltage conversion module. The DC charging interface is used to connect the positive and negative terminals of the power supply device and the positive and negative terminals of the power battery to form a charging circuit. The switching module is used to turn the charging circuit on or off. The DC voltage conversion module is used to output a preset DC voltage to the positive and negative terminals of the power supply device.

[0006] In this embodiment, the DC charging device includes a DC voltage conversion module that has the function of outputting a preset DC voltage to the positive and negative terminals of the power supply device. When the DC voltage conversion module needs to output a preset DC voltage to the positive and negative terminals of the power supply device, it can perform its function and output the preset DC voltage to the positive and negative terminals of the power supply device. Therefore, when the power supply device is connected to the electric vehicle and charges the electric vehicle's power battery, if the charging circuit between the electric vehicle's power battery and the power supply device is disconnected, the DC voltage conversion module outputs a preset DC voltage to the power supply device. Since the charging circuit is disconnected, the DC voltage conversion module outputs a preset DC voltage to the power supply device. After the charging circuit is reconnected, the user does not need to swipe the card / scan the code again to resume charging, reducing user operations and thus improving the user experience.

[0007] In one implementation of the first aspect, the switching module is used to disconnect the charging circuit in response to the DC voltage conversion module outputting a preset DC voltage.

[0008] In this implementation, since the DC voltage conversion module first outputs a preset DC voltage, the switching module responds to the preset DC voltage output by the DC voltage conversion module by disconnecting the charging circuit. Therefore, there is no possibility that the charging circuit will be disconnected while the DC voltage conversion module fails to output the preset DC voltage. Thus, this implementation can prevent the power supply device from immediately alarming due to detecting a disconnected charging circuit but not receiving the preset DC voltage, reducing the likelihood of power supply device alarms.

[0009] In one implementation of the first aspect, the DC voltage conversion module is used to stop outputting a preset DC voltage in response to the switching module turning on the charging circuit.

[0010] In this implementation, since the switching module first turns on the charging circuit, the DC voltage conversion module responds by turning on the charging circuit and stops outputting the preset DC voltage. There is no possibility that the DC voltage conversion module will stop outputting the preset DC voltage while the charging circuit is disconnected. Therefore, this implementation can prevent the power supply device from immediately alarming due to detecting a disconnected charging circuit but not receiving the preset DC voltage, reducing the likelihood of an alarm from the power supply device.

[0011] In one implementation of the first aspect, the switch module is used to: disconnect the charging circuit in response to the temperature of the power battery being lower than a preset temperature; and connect the charging circuit in response to the temperature of the power battery being greater than or equal to the preset temperature.

[0012] In this implementation, the switching module can coordinate with the electric vehicle's battery heating function to selectively disconnect or connect the charging circuit. When the battery temperature is low and requires heating, the switching module disconnects the charging circuit when the battery temperature is below a preset temperature, preventing low charging power or even failure to charge due to low temperatures. As the battery temperature gradually rises, the switching module connects the charging circuit when the battery temperature is above or equal to the preset temperature, allowing charging to proceed when the battery is ready for charging, resulting in normal charging power and improved charging efficiency.

[0013] In one implementation of the first aspect, the DC voltage conversion module is used to: output a preset DC voltage in response to the temperature of the power battery being lower than a preset temperature; and stop outputting the preset DC voltage in response to the temperature of the power battery being greater than or equal to the preset temperature.

[0014] In this implementation, the DC-DC voltage conversion module can work in conjunction with the heating function of the electric vehicle's power battery to selectively output or stop outputting a preset DC voltage. When the power battery temperature is low and heating is required, the charging circuit is disconnected during heating. In response to the power battery temperature being lower than the preset temperature, the DC-DC voltage conversion module outputs the preset DC voltage, preventing alarms caused by the disconnected charging circuit. As the power battery temperature gradually rises, in response to the power battery temperature being greater than or equal to the preset temperature, the DC-DC voltage conversion module stops outputting the preset DC voltage. This prevents the power battery voltage from continuously decreasing due to the continuous output of the preset DC voltage, thus protecting the power battery.

[0015] In one implementation of the first aspect, the DC charging device includes a control circuit, which is used to: in response to the DC charging interface being connected to the positive and negative terminals of the power supply device, control the DC voltage conversion module to output or stop outputting a preset DC voltage and control the switch module to turn on or off the charging circuit based on a comparison between the temperature of the power battery and a preset temperature; and in response to the DC charging interface not being connected to the positive and negative terminals of the power supply device, control the DC voltage conversion module to stop outputting the preset DC voltage.

[0016] In this implementation, in response to the DC charging interface being connected to the positive and negative terminals of the power supply device, the switching module controls the DC voltage conversion module to output or stop outputting the preset DC voltage based on a comparison between the power battery temperature and a preset temperature. This controls the switching module to turn the charging circuit on or off, preventing low charging power or even charging failure when the power battery temperature is too low. It also prevents the power supply device from detecting a charging circuit disconnection and triggering an alarm for abnormal charging. Conversely, in response to the DC charging interface not being connected to the positive and negative terminals of the power supply device, the DC voltage conversion module stops outputting the preset DC voltage to the positive and negative terminals of the power supply device. This prevents the DC voltage conversion module from continuously outputting the preset DC voltage converted from the power battery to the positive and negative terminals of the power supply device, thus protecting the power battery.

[0017] In one implementation of the first aspect, the electric vehicle includes a motor controller and a motor. The motor controller is used to connect or disconnect the discharge circuit between the power battery and the motor. The control circuit is used to: control the motor controller to connect the discharge circuit in response to the power battery temperature being lower than a preset temperature; and control the motor controller to disconnect the discharge circuit in response to the power battery temperature being greater than or equal to the preset temperature.

[0018] In this implementation, the control circuit controls the motor controller to open the discharge circuit in response to the power battery temperature being lower than a preset temperature, thereby heating the power battery and improving its charging efficiency. As the power battery temperature rises, the control circuit controls the motor controller to close the discharge circuit in response to the power battery temperature being greater than or equal to the preset temperature, in order to prevent the power battery from overheating.

[0019] In one implementation of the first aspect, the DC charging interface includes two battery connection terminals and two power connection terminals. The two battery connection terminals are used to connect to the positive and negative terminals of the power battery, respectively, and the two power connection terminals are used to connect to the positive and negative terminals of the power supply device, respectively. The DC voltage conversion module receives power from the power battery through the two battery connection terminals and outputs a preset DC voltage through the two power connection terminals.

[0020] In this implementation, the two battery connection terminals and the two power connection terminals are terminals on the DC charging interface. The DC voltage conversion module receives power from the power battery through the two battery connection terminals and outputs a preset DC voltage to the power supply device through the two power connection terminals, which can avoid alarms from the power supply device caused by abnormal charging. In addition, the DC voltage conversion module is connected to the two battery connection terminals and the two power connection terminals of the DC charging interface, which is compatible with the terminals on the DC charging interface and facilitates integration.

[0021] In one implementation of the first aspect, the DC-DC voltage conversion module includes a diode, a resistor, a capacitor, and a controllable switch. The anode of the diode is connected to a battery terminal, and the cathode of the diode is connected to a power supply terminal via the resistor and the controllable switch. The battery terminal is used to connect to the positive terminal of the power battery, and the power supply terminal is used to connect to the positive terminal of the power supply device. One end of the capacitor is connected between the resistor and the switch, and the other end of the capacitor is connected to another battery terminal and another power supply terminal. The other battery terminal is used to connect to the negative terminal of the power battery, and the other power supply terminal is used to connect to the negative terminal of the power supply device.

[0022] In this implementation, the voltage conversion module includes diodes, resistors, capacitors, and switches. When the switch is closed, the voltage conversion module outputs a preset DC voltage to the power supply. When the switch is open, the voltage conversion module stops outputting the preset DC voltage to the power supply. The function of the voltage conversion module can be achieved through simple operation. Furthermore, this voltage conversion module includes fewer components, which facilitates integration and reduces costs, offering certain advantages.

[0023] In one implementation of the first aspect, the switch module includes two additional controllable switches. One controllable switch is used to connect or disconnect a power connection terminal and a battery connection terminal. The other controllable switch is used to connect or disconnect another power connection terminal and another battery connection terminal.

[0024] Secondly, embodiments of this application provide a powertrain. The powertrain includes a motor, a motor controller, and a DC charging device as described in the first aspect. The motor controller is used to connect or disconnect the discharge circuit between the power battery and the motor.

[0025] In this embodiment, the motor controller is used to connect or disconnect the discharge circuit between the power battery and the motor. When the temperature of the power battery is lower than a preset temperature, the motor controller controls the discharge circuit to be connected to heat the power battery, which helps improve the charging efficiency of the power battery. As the temperature of the power battery rises, when the temperature of the power battery is greater than or equal to the preset temperature, the motor controller controls the discharge circuit to be disconnected to prevent the power battery from overheating.

[0026] In one implementation of the second aspect, the motor controller is used to turn on the discharge circuit in response to the switching module disconnecting the charging circuit.

[0027] In this implementation, the charging circuit is disconnected, indicating that it is not suitable to charge the power battery at this time. In response to the switching module disconnecting the charging circuit, the motor controller turns on the discharge circuit to heat the power battery, avoiding charging the power battery when its temperature is too low, which would result in low charging power or even no charging at all.

[0028] In one implementation of the second aspect, the motor controller is used to disconnect the discharge circuit in response to the discharge circuit's conduction duration being greater than or equal to a preset duration.

[0029] In this implementation, the temperature of the power battery continuously rises as the discharge circuit is activated. When the conduction time of the discharge circuit is greater than or equal to a preset time, the power battery is ready to be charged. In response to the discharge circuit's conduction time being greater than or equal to the preset time, the motor controller disconnects the discharge circuit to stop heating the power battery and prevent excessively high battery temperatures from affecting its lifespan.

[0030] In one implementation of the second aspect, the motor controller includes a control circuit and an inverter circuit. The inverter circuit includes three bridge arm circuits, with each bridge arm's two ends used to connect to the positive and negative terminals of the power battery, respectively. The midpoints of the three bridge arm circuits are used to connect to one phase winding of the motor. The control circuit controls the upper bridge arm switch of one bridge arm to conduct and controls the lower bridge arm switch of another bridge arm to conduct, thus enabling the motor controller to conduct the discharge circuit. Alternatively, the control circuit can control the upper and lower bridge arm switches of multiple bridge arms to remain open, thus enabling the motor controller to disconnect the discharge circuit.

[0031] In this implementation, the control circuit controls the upper bridge arm switch of one bridge arm and the lower bridge arm switch of another bridge arm to conduct, and the motor controller conducts the discharge circuit to heat the power battery, which helps to improve the charging efficiency of the power battery. Alternatively, the control circuit can keep the upper and lower bridge arm switches of multiple bridge arms disconnected, and the motor controller can disconnect the discharge circuit to stop heating the power battery, thus preventing the power battery from overheating and affecting its lifespan.

[0032] For any possible technical effects not mentioned in the second aspect, please refer to the description of the technical effects that any possible design could achieve in the first aspect above, which will not be repeated here.

[0033] Thirdly, embodiments of this application provide an electric vehicle, which includes a power battery, a vehicle controller, a motor controller, a motor, and a DC charging device as described in the first aspect. The power battery includes a battery management unit for detecting the temperature of the power battery. The vehicle controller controls at least one of the DC charging device or the motor controller based on a comparison between the temperature of the power battery and a preset temperature.

[0034] For any possible technical effect involved in the third aspect, please refer to the description of any possible design technical effect in the first aspect above, which will not be repeated here. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of an electric vehicle provided in an embodiment of this application.

[0036] Figure 2 This is a schematic diagram of a DC charging device provided in an embodiment of this application.

[0037] Figure 3 Another schematic diagram of the DC charging device provided in the embodiments of this application.

[0038] Figure 4 Another schematic diagram of the DC charging device provided in the embodiments of this application.

[0039] Figure 5 This is a schematic diagram of a current loop provided in an embodiment of this application.

[0040] Figure 6 Another schematic diagram of the DC charging device provided in the embodiments of this application.

[0041] Figure 7 This is a schematic diagram of another current loop provided in an embodiment of this application.

[0042] Figure 8 This is a schematic diagram of a powertrain provided in an embodiment of this application.

[0043] Figure 9 This is a schematic diagram of a discharge circuit provided in an embodiment of this application.

[0044] Figure 10 This is a schematic diagram of a charging circuit provided in an embodiment of this application.

[0045] Figure 11 This is a schematic diagram of a battery low-temperature heating method provided in an embodiment of this application. Detailed Implementation

[0046] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0047] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone.

[0048] References to “some embodiments” and the like in this specification mean that one or more embodiments of this application include a particular feature, structure, or characteristic described in connection with that embodiment. Therefore, phrases such as “some embodiments” appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean “one or more, but not all, embodiments”, unless otherwise specifically emphasized. The terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise specifically emphasized.

[0049] The term "equal to" in this application is not equal in the strict sense, but rather within the allowable range of error.

[0050] With the development of new energy vehicle technology, many car manufacturers have gradually launched electric vehicles. Electric vehicles have become the choice of many users due to their energy saving, environmental protection and relatively mature technology.

[0051] After an electric vehicle (EV) connects to a charging station, the user typically needs to swipe a card / scan a code. The charging station then charges the EV through a charging circuit between the EV's battery and the station. For user safety, the EV can only charge in non-operating mode. When the EV's battery is charging, the charging circuit between the battery and the charging station is disconnected, and the charging station will usually stop charging. Once the charging circuit is reconnected, the user usually needs to swipe their card / scan the code again to resume charging.

[0052] Based on this, this application provides a DC charging device, a powertrain, and an electric vehicle. The DC charging device outputs a preset DC voltage to the power supply device as needed. After the charging circuit between the electric vehicle's power battery and the charging pile is disconnected, it is reconnected, eliminating the need for the user to swipe their card / scan their code again, thus improving the user experience. The following detailed descriptions of the DC charging device, powertrain, and electric vehicle are provided in conjunction with specific embodiments.

[0053] Figure 1 This is a schematic diagram of an electric vehicle provided as an embodiment of this application. (For example...) Figure 1 As shown, the electric vehicle includes a power battery 10 and a powertrain 20. The powertrain 20 is used to drive the electric vehicle or to heat the power battery 10. The powertrain 20 includes a motor controller 21, a motor 22, and a DC charging device 30. The motor controller 21 is used to control the operation or shutdown of the motor 22.

[0054] Figure 2 This is a schematic diagram of a DC charging device provided in an embodiment of this application. The DC charging device 30 is used to charge the power battery 10 of an electric vehicle. The DC charging device 30 includes a DC charging interface 31, a switching module 32, and a DC voltage conversion module 33.

[0055] In this embodiment, the DC charging interface 31 is used to connect the positive and negative terminals of the power supply device and the positive and negative terminals of the power battery 10 to form a charging circuit.

[0056] The power supply device in this embodiment is a charging pile or other device capable of providing charging energy. The power supply device forms a charging circuit with the power battery 10 via a DC charging interface 31. The power supply device is connected to the electric vehicle, and charges the electric vehicle's power battery 10 via the DC charging interface 31.

[0057] In this embodiment, the connection or disconnection of the charging circuit is controlled by a switch module 32. The switch module 32 includes a controllable switch. When the controllable switch is closed, the charging circuit is connected. When the controllable switch is closed, the charging circuit is disconnected.

[0058] In this embodiment, the DC voltage conversion module 33 is used to output a preset DC voltage to the positive and negative terminals of the power supply device.

[0059] In one embodiment, the DC voltage conversion module 33 is used to convert the voltage of the power battery 10 into a preset DC voltage and output the preset DC voltage to the positive and negative terminals of the power supply device. In another embodiment, the DC voltage conversion module 33 is used to convert the voltage of the electric vehicle's battery into a preset DC voltage and output the preset DC voltage to the positive and negative terminals of the power supply device.

[0060] As mentioned above, when the electric vehicle's power battery is charging, the charging circuit between the electric vehicle's power battery and the charging pile is disconnected, and the charging pile will usually stop charging. Furthermore, in some scenarios, the charging pile may also trigger an alarm indicating a charging abnormality due to the disconnection of the charging circuit. Therefore, the DC voltage conversion module 33 in this embodiment can supply a preset DC voltage to the positive and negative terminals of the power supply device to deceive the power supply device into believing that it is connected to the electric vehicle's charging circuit, thus preventing the power supply device from triggering an alarm.

[0061] In this embodiment, the preset DC voltage is related to the minimum allowable voltage at which the charging circuit formed by the power supply device and the power battery 10 is disconnected but the power supply device does not alarm. For example, if the minimum allowable voltage of the power supply device is 380V, then the preset DC voltage is greater than or equal to 380V; if the minimum allowable voltage of the power supply device is 220V, then the preset DC voltage is greater than or equal to 220V. The DC voltage conversion module 33 simply outputs the preset DC voltage to the power supply device.

[0062] In this embodiment, the power supply device is connected to the electric vehicle. After the user swipes their card / scans a code, the electric vehicle's switch module 32 closes, and the power supply device charges the power battery 10 through the DC charging interface 31. However, during the charging process, the switch module 32 needs to disconnect the charging circuit in some scenarios. Once the charging circuit is disconnected, the power supply device will detect an abnormal charging situation and trigger an alarm. To prevent the power supply device from triggering an alarm when the charging circuit is disconnected, the DC voltage conversion module 33 outputs a voltage to the power supply device to deceive it into believing that the electric vehicle is still connected to it. Since the power supply device believes that it is continuously connected to the electric vehicle, charging can resume without the user swiping their card / scanning a code again once the charging circuit is reconnected.

[0063] In this embodiment, the DC charging device 30 includes a DC voltage conversion module 33 that has the function of outputting a preset DC voltage to the positive and negative terminals of the power supply device. When the DC voltage conversion module 33 needs to output a preset DC voltage to the positive and negative terminals of the power supply device, it can perform its function to output the preset DC voltage to the positive and negative terminals of the power supply device. Therefore, when the power supply device is connected to the electric vehicle and charges the electric vehicle's power battery 10, if the charging circuit of the electric vehicle's power battery 10 is disconnected from the power supply device, the DC voltage conversion module 33 outputs a preset DC voltage to the power supply device. Since the charging circuit is disconnected, the DC voltage conversion module 33 outputs a preset DC voltage to the power supply device. After the charging circuit is reconnected, the user does not need to swipe the card / scan the code again to resume charging, reducing user operations and thus improving the user experience.

[0064] The above embodiments illustrate the functions of the switching module 32 and the DC-DC voltage conversion module 33. The operating logic of the switching module 33 and the DC-DC voltage conversion module 33 will be described in detail below.

[0065] In one embodiment, the switch module 32 is used to disconnect the charging circuit in response to the DC voltage conversion module 33 outputting a preset DC voltage.

[0066] In this embodiment, during the charging process of the power supply device to the power battery 10, in some scenarios, the DC voltage conversion module 33 needs to output a preset DC voltage to the power supply device. In this embodiment, since the DC voltage conversion module 33 outputs the preset DC voltage first, the switching module 32 disconnects the charging circuit in response to the DC voltage conversion module 33 outputting the preset DC voltage to the power supply device. This eliminates the possibility of the charging circuit being disconnected while the DC voltage conversion module 33 fails to output the preset DC voltage, preventing the power supply device from immediately alarming due to detecting the charging circuit being disconnected but not receiving the preset DC voltage, thus reducing the likelihood of the power supply device alarming.

[0067] It is worth mentioning that during the charging process of the power supply device to the power battery 10, if the switch module 32 disconnects the charging circuit first, and the DC voltage conversion module 33 outputs a preset DC voltage to the power supply device in response to the disconnection of the charging circuit, it is possible that the DC voltage conversion module 33 will not output the preset DC voltage in time after the charging circuit is disconnected, causing the power supply device to alarm. However, in this embodiment, since the switch module 32 disconnects the charging circuit in response to the DC voltage conversion module 33 outputting the preset DC voltage, it can prevent the power supply device from detecting that the charging interface is disconnected but not receiving the preset DC voltage and causing an immediate alarm.

[0068] In one embodiment, the DC voltage conversion module 33 is used to stop outputting a preset DC voltage in response to the switching module 32 turning on the charging circuit.

[0069] In this embodiment, when the DC voltage conversion module 33 outputs a preset DC voltage to the power supply device and the switching module 32 disconnects the charging circuit, the switching module 32 may, as needed, turn on the charging circuit. In this embodiment, since the switching module 32 turns on the charging circuit first, in response to the turn-on of the charging circuit, the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device. There is no possibility that the DC voltage conversion module 33 will stop outputting the preset DC voltage while the charging circuit is disconnected. This prevents the power supply device from immediately alarming due to detecting a disconnected charging circuit but not receiving the preset DC voltage, reducing the likelihood of an alarm from the power supply device.

[0070] It is worth mentioning that, when the DC voltage conversion module 33 outputs a preset DC voltage to the power supply device and the switching module 32 disconnects the charging circuit, if the DC voltage conversion module 33 stops outputting the preset DC voltage first, and the switching module 32 turns on the charging circuit in response to the cessation of the preset DC voltage output, it is possible that after the preset DC voltage output stops, the switching module 32 fails to turn on the charging circuit in time within a short period of time. At this time, the charging circuit is disconnected, the DC voltage conversion module 33 stops outputting voltage, and the power supply device will alarm for charging abnormality. However, in this embodiment, since the DC voltage conversion module 33 stops outputting the preset DC voltage in response to the switching module 32 turning on the charging circuit, it can prevent the power supply device from detecting that the charging interface is disconnected but not receiving the preset DC voltage and causing an immediate alarm.

[0071] The operation of the switch module 32 and DC voltage conversion module 33 provided in the embodiments of this application will be further explained below.

[0072] In this embodiment, the switch module 32 disconnects or connects the charging circuit based on the comparison result between the temperature of the power battery 10 and the preset temperature.

[0073] In one embodiment, the temperature of the power battery 10 is the cell temperature of the power battery 10. In another embodiment, the temperature of the power battery 10 is the surface temperature of the power battery 10.

[0074] In this embodiment, the switch module 32 disconnects the charging circuit in response to the temperature of the power battery 10 being lower than a preset temperature. The switch module 32 then connects the charging circuit in response to the temperature of the power battery 10 being greater than or equal to the preset temperature.

[0075] In one embodiment, the preset temperature is a preset power battery temperature. For example, the preset power battery temperature is -5 degrees Celsius. If the temperature of the power battery 10 is less than -5 degrees Celsius, it indicates that the power battery 10 is too cold, which can lead to severe capacity degradation, low charging power, or even failure to charge. In response to the power battery 10's temperature being less than -5 degrees Celsius, the switch module 32 disconnects the charging circuit to prevent the power battery 10 from charging at low temperatures, which would result in low charging power or even failure to charge. When the switch module 32 disconnects the charging circuit, the DC voltage conversion module 33 outputs a preset DC voltage to the positive and negative terminals of the power supply device. The power supply device considers itself still connected to the electric vehicle. After the charging circuit is reconnected, charging can resume without the user needing to reconnect by swiping a card / scanning a code, reducing user operations. Furthermore, since the DC voltage conversion module 33 in this embodiment outputs a preset DC voltage to the positive and negative terminals of the power supply device when the charging circuit is disconnected, it can prevent the power supply device from alarming for charging abnormalities when the charging circuit is disconnected, improving the user experience.

[0076] When the temperature of the power battery 10 is greater than or equal to -5 degrees Celsius, the capacity decay of the power battery 10 is relatively reduced, making the power battery 10 suitable for charging. In response to the temperature of the power battery 10 being greater than or equal to 5 degrees Celsius, the switching module 32 activates the charging circuit, allowing the power supply device to charge the power battery 10 and complete the charging process. Because the switching module 32 activates the charging circuit in response to the temperature of the power battery 10 being greater than or equal to a preset temperature, charging the power battery 10 when it is suitable for charging improves charging efficiency.

[0077] In this embodiment, the DC voltage conversion module 33 outputs a preset DC voltage or stops outputting the preset DC voltage based on the comparison result between the temperature of the power battery 10 and the preset temperature.

[0078] In one embodiment, the DC-DC voltage conversion module 33 outputs a preset DC voltage in response to the temperature of the power battery 10 being lower than a preset temperature. The DC-DC voltage conversion module 33 stops outputting the preset DC voltage in response to the temperature of the power battery 10 being greater than or equal to the preset temperature.

[0079] For example, the preset temperature of the power battery is -5 degrees Celsius. When the temperature of the power battery 10 is below -5 degrees Celsius, the charging power of the power battery 10 is low or even unable to charge, requiring heating. In response to the temperature of the power battery 10 being below 5 degrees Celsius, the DC voltage conversion module 33 outputs a preset DC voltage to the positive and negative terminals of the power supply device. In this embodiment, the motor controller 21 controls the drive motor 22 to operate to heat the power battery 10. By driving the motor 22 to heat the power battery 10, the switch module 32 controls the charging circuit to disconnect, preventing the AC power generated by the motor controller 21 driving the motor 22 from entering the power supply device and causing damage. Simultaneously, because the DC voltage conversion module 33 outputs a preset DC voltage to the positive and negative terminals of the power supply device, even if the charging circuit is disconnected, the power supply device still considers itself connected to the electric vehicle. Once the charging circuit is reconnected, charging can be resumed without the user needing to swipe the card / scan the code again, improving the user experience.

[0080] When the temperature of the power battery 10 is greater than or equal to -5 degrees Celsius, the power battery 10 is suitable for charging. In response to the power battery 10's temperature being greater than or equal to a preset temperature, the DC-DC voltage conversion module 33 stops outputting the preset DC voltage, preventing a continuous drop in the power battery 10's voltage due to continuous output of the preset DC voltage, thus protecting the power battery 10. For the power battery 10 with a temperature greater than or equal to -5 degrees Celsius, the charging efficiency of the power supply device can be improved.

[0081] In one embodiment, the switching module 32 turns on the charging circuit in response to the charging circuit being disconnected for a duration greater than or equal to a preset duration.

[0082] In one embodiment, in response to the charging circuit being disconnected for a duration greater than or equal to a preset duration, the DC voltage conversion module 33 stops outputting a preset DC voltage to the positive and negative terminals of the power supply device.

[0083] It should be noted that, in response to the temperature of the power battery 10 being lower than the preset temperature, the DC voltage conversion module 33 outputs a preset DC voltage to the positive and negative terminals of the power supply device, and the switch module 32 disconnects the charging circuit. In this state, the motor controller 21 can drive the motor 22 to heat the power battery 10. Therefore, the duration of the charging circuit being disconnected is the duration of heating the power battery 10.

[0084] For example, the preset duration is 10 minutes, and the duration of the charging circuit disconnection is greater than or equal to 10 minutes, that is, the duration of heating the power battery 10 is greater than or equal to 10 minutes. During the preset duration, the power battery 10 is heated, and its temperature rises. When the temperature of the power battery 10 rises to the preset temperature, the charging power of the power battery 10 is normal, and the power battery 10 is suitable for charging. Therefore, in this embodiment, in response to the charging circuit being disconnected for a duration greater than or equal to 10 minutes, the switch module 32 turns on the charging circuit, and the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device. Since the switch module 32 turns on the charging circuit, and the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device, the power supply device can normally charge the power battery 10, completing the charging of the power battery 10.

[0085] In this embodiment, in response to the charging circuit being disconnected for a duration greater than or equal to a preset duration, the switching module 32 turns on the charging circuit. When the power battery 10 is suitable for charging, the power supply device charges the power battery 10, thereby improving charging efficiency. Furthermore, in response to the charging circuit being disconnected for a duration greater than the preset duration, the DC voltage conversion module 33 stops outputting a preset DC voltage to the positive and negative terminals of the power supply device. Since the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device, it is equivalent to the DC voltage conversion module 33 stopping its operation. The DC voltage conversion module 33 does not consume the power output by the power supply device, further improving charging efficiency.

[0086] In this embodiment, the switch module 32 disconnects or connects the charging circuit depending on whether the electric vehicle is running. The DC voltage conversion module 33 outputs a preset DC voltage or stops outputting a preset DC voltage depending on whether the electric vehicle is running.

[0087] In one embodiment, the switch module 32 is configured to disconnect the charging circuit in response to the operation of the electric vehicle. In response to the cessation of operation of the electric vehicle, the switch module 32 is configured to connect the charging circuit.

[0088] In one embodiment, in response to the operation of the electric vehicle, the DC voltage conversion module 33 outputs a preset DC voltage to the positive and negative terminals of the power supply device. In response to the cessation of operation of the electric vehicle, the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device.

[0089] In this embodiment, the operation of the electric vehicle can be understood as starting the electric vehicle but without significant movement. For example, the electric vehicle is connected to a power supply device, the switch module 32 is closed, and the power supply device charges the power battery 10 through the DC charging interface 31. During the charging process, if the electric vehicle needs to be operated, the user typically needs to click "stop charging" before it can be started; otherwise, a charging abnormality alarm will sound. However, because the DC voltage conversion module 33 of this embodiment outputs a preset DC voltage to the positive and negative terminals of the power supply device, even if the electric vehicle is running after the switch module 32 disconnects the charging circuit, the power supply device will not alarm. This is mainly because the DC voltage conversion module 33 outputs a preset DC voltage to the positive and negative terminals of the power supply device, causing the power supply device to believe that the electric vehicle is still in a normal connection state. It is precisely because of the existence of the DC voltage conversion module 33 that it can function when its output voltage is needed, preventing the power supply device from alarming for charging abnormality after the charging circuit is disconnected, and eliminating the need for the user to click "stop charging" and then reconnect by swiping a card / scanning a code, thus improving the user experience.

[0090] When the electric vehicle stops operating, the switch module 32 reconnects the charging circuit, and the DC charging module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device. Since the switch module 32 connects the charging circuit and the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device, the power supply device can then normally charge the power battery 10, completing the charging process. Furthermore, because the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device, it is equivalent to the DC voltage conversion module 33 stopping its operation. Therefore, the DC voltage conversion module 33 does not consume the power output of the power supply device, further improving charging efficiency.

[0091] Figure 3 This is another schematic diagram of a DC charging device provided in an embodiment of this application. In one embodiment, the DC charging device 30 includes a control circuit 34, which is used to control the DC voltage conversion module 33 to output or stop outputting a preset DC voltage and control the switch module 32 to turn on or off the charging circuit in response to the positive and negative terminals of the power supply device connected to the DC charging interface 31, based on a comparison between the temperature of the power battery and a preset temperature.

[0092] In response to the fact that the DC charging interface 31 is not connected to the positive or negative terminal of the power supply device, the control circuit 34 controls the DC voltage conversion module 33 to stop outputting the preset DC voltage.

[0093] In this embodiment, the DC charging interface 31 is connected to the positive and negative terminals of the power supply device, indicating that the power supply device is prepared to charge the power battery 10 through the DC charging interface 31. However, the temperature of the power battery 10 is too low, and considering that the charging power is low or even impossible at low temperatures, it is not suitable to charge the power battery 10 when the temperature is too low. Therefore, the control circuit 34 can control the DC voltage conversion module 33 to output or stop outputting the preset DC voltage and control the switch module 32 to turn on or off the charging circuit based on the comparison between the temperature of the power battery 10 and the preset temperature.

[0094] Specifically, in response to the temperature of the power battery 10 being lower than a preset temperature, the control circuit 34 controls the DC voltage conversion module 33 to output a preset DC voltage and controls the switch module 32 to disconnect the charging circuit. In this case, the motor controller 21 drives the motor 22 to run to heat the power battery 10. As the temperature of the power battery 10 gradually rises, in response to the temperature of the power battery 10 being greater than or equal to the preset temperature, the power battery 10 is suitable for charging. The control circuit 34 controls the DC voltage conversion module 33 to stop outputting the preset DC voltage and controls the switch module 32 to turn on the charging circuit. Charging the power battery 10 when its temperature is suitable can improve charging efficiency.

[0095] If the DC charging interface 31 is not connected to the positive and negative terminals of the power supply device, it indicates that the power supply device is not charging the power battery 10. The power supply device will not trigger an alarm for charging abnormality, and the DC voltage conversion module 33 has no need to output the preset DC voltage to the positive and negative terminals of the power supply device. Therefore, the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device. If the DC charging interface 31 is not connected to the positive and negative terminals of the power supply device, but the DC voltage conversion module 33 still outputs the preset DC voltage to the positive and negative terminals of the power supply device, this will further cause the voltage of the power battery 10 to drop, reducing the driving range of the power battery 10.

[0096] In this embodiment, in response to the DC charging interface 31 being connected to the positive and negative terminals of the power supply device, the switch module 32 controls the DC voltage conversion module 33 to output or stop outputting the preset DC voltage based on the comparison result between the temperature of the power battery 10 and the preset temperature, and controls the switch module 32 to turn the charging circuit on or off. This prevents the power battery 10 from being charged when its temperature is too low, which would result in low charging power or even no charging. Simultaneously, it also prevents the power supply device from detecting a charging circuit disconnection and triggering an alarm for abnormal charging. In response to the DC charging interface 31 not being connected to the positive and negative terminals of the power supply device, the DC voltage conversion module 33 stops outputting the preset DC voltage to the positive and negative terminals of the power supply device. This prevents the DC voltage conversion module 33 from continuously outputting the preset DC voltage converted from the power battery 10 to the positive and negative terminals of the power supply device, which would cause the voltage of the power battery 10 to continuously decrease, thus protecting the power battery 10.

[0097] In one embodiment, the electric vehicle includes a motor controller 21 and a motor 22, wherein the motor controller 21 is used to connect or disconnect the discharge circuit between the power battery 10 and the motor 22.

[0098] Control circuit 34 is used to control motor controller 21 to conduct the discharge circuit in response to the temperature of power battery 10 being lower than the preset temperature.

[0099] Control circuit 34 is used to control motor controller 21 to disconnect the discharge circuit in response to the temperature of power battery 10 being greater than or equal to a preset temperature.

[0100] In this embodiment, the temperature of the power battery 10 is lower than a preset temperature, making it unsuitable for charging. The control circuit 34 controls the motor controller 21 to conduct the discharge circuit. During the charging and discharging process of the power battery 10, the current generates heat on the internal resistance of the power battery 10, thereby heating the power battery 10.

[0101] As the power battery 10 continues to heat up, its temperature gradually increases. When the temperature of the power battery 10 is greater than or equal to a preset temperature, the power battery 10 is ready for charging. The control circuit 34 controls the motor controller 21 to disconnect the discharge circuit to prevent the power battery 10 from overheating. When the power battery 10 is ready for charging, the switching module 32 connects the positive and negative terminals of the power supply device and the power battery to form a charging circuit to charge the power battery 10, thereby improving charging efficiency.

[0102] In this embodiment, the control circuit 34 controls the motor controller 21 to conduct the discharge circuit in response to the temperature of the power battery 10 being lower than a preset temperature, thereby heating the power battery 10 and improving its charging efficiency. As the temperature of the power battery 10 increases, the control circuit 34 controls the motor controller 21 to disconnect the discharge circuit in response to the temperature of the power battery 10 being greater than or equal to the preset temperature, thus preventing the power battery 10 from overheating.

[0103] In one embodiment, the DC charging interface 31 includes two battery connection terminals and two power connection terminals. The two battery connection terminals are used to connect to the positive and negative terminals of the power battery 10, respectively, and the two power connection terminals are used to connect to the positive and negative terminals of the power supply device, respectively.

[0104] The DC voltage conversion module 33 receives power from the power battery 10 through two battery connection terminals, and outputs a preset DC voltage through two power connection terminals.

[0105] In this embodiment, the two battery connection terminals and the two power connection terminals are terminals on the DC charging interface 31. The DC voltage conversion module 33 receives power from the power battery 10 through the two battery connection terminals and outputs a preset DC voltage to the power supply device through the two power connection terminals, which can avoid alarms from the power supply device caused by abnormal charging. In addition, the DC voltage conversion module 33 is connected to the two battery connection terminals and the two power connection terminals of the DC charging interface 31, which is compatible with the terminals on the DC charging interface 31 and facilitates integration.

[0106] Figure 4 Another schematic diagram of a DC charging device provided in an embodiment of this application is shown below. Figure 4 The circuit topology diagram of DC voltage conversion module 33 is shown.

[0107] In one embodiment, the DC voltage conversion module 33 includes a diode, a resistor, a capacitor, and a controllable switch.

[0108] The diode's anode is connected to a battery terminal, and its cathode is connected to a power supply terminal via a resistor and a controllable switch. The battery terminal is used to connect to the positive terminal of the power battery 10, and the power supply terminal is used to connect to the positive terminal of the power supply device.

[0109] One end of the capacitor is connected between the resistor and the switch, and the other end of the capacitor is connected to another battery terminal and another power supply terminal. The other battery terminal is used to connect to the negative terminal of the power battery 10, and the other power supply terminal is used to connect to the negative terminal of the power supply device.

[0110] refer to Figure 4The voltage conversion module 33 includes a diode D, a resistor R, a capacitor C1, and a switch K7. The diode D, resistor R, and switch K7 are connected in series between the positive terminal of the battery connection and the positive terminal of the power supply connection. One end of capacitor C1 is connected between resistor R and switch K7, and the other end of capacitor C1 is connected between the negative terminal of the battery connection and the negative terminal of the power supply connection.

[0111] When the voltage conversion module 33 needs to output a preset DC voltage to the positive and negative terminals of the power supply device, the switch K7 closes, and the battery flows as follows: Figure 5 The direction of the middle arrow. Current flows out from the positive terminal of the power battery 10, through diode D, resistor R, and switch K7 into the positive terminal of the power supply device, and current flows out from the negative terminal of the power supply device into the negative terminal of the power battery 10, forming a DC voltage output circuit.

[0112] When the voltage conversion module 33 does not need to output a preset DC voltage to the positive and negative terminals of the power supply device, the switch K7 is opened, and the voltage conversion module 33 cannot output a preset DC voltage to the power supply device.

[0113] It should be noted that capacitor C1 and resistor R together form a filter circuit to filter out the AC current superimposed on the DC output of the power battery 10. For example, assuming the power battery 10 outputs 380V DC, and a 50V AC current is superimposed on this DC, the AC current can be filtered out by setting the capacitance of capacitor C1 and the value of resistor R, thereby outputting 380V DC to the power supply device.

[0114] In this embodiment, the voltage conversion module 33 includes a diode D, a resistor R, a capacitor C1, and a switch K7. When switch K7 is closed, the voltage conversion module 33 outputs a preset DC voltage to the power supply device. When switch K7 is open, the voltage conversion module 33 stops outputting the preset DC voltage to the power supply device. The function of the voltage conversion module 33 can be achieved through simple operation. Furthermore, this voltage conversion module 33 includes fewer components, which facilitates integration and reduces costs, offering certain advantages.

[0115] In one embodiment, the switch module 32 includes two additional controllable switches.

[0116] One of the controllable switches is used to connect or disconnect the connection between a power supply terminal and a battery terminal.

[0117] Another controllable switch is used to connect or disconnect the connection between another power supply terminal and another battery terminal.

[0118] In this embodiment, the controllable switch can be a power switch, a relay, etc. The power switch can be one or more of various types of switching transistors, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) and an insulated-gate bipolar transistor (IGBT). The relay can be one or more of various types of relays, such as a signal relay and a temperature relay. These will not be listed one by one in this embodiment.

[0119] In this embodiment, taking an IGBT as an example, the IGBT includes a gate G, a collector C, and an emitter E. The gate G of the IGBT is used to control the IGBT's on / off state. When the IGBT is on, current can flow between the collector C and the emitter E. When the IGBT is off, no current can flow between the collector C and the emitter E.

[0120] Figure 6 Another schematic diagram of a DC charging device provided in an embodiment of this application. (See also...) Figure 6 The switching module 32 includes switching transistors V5 and V6. The collector C of switching transistor V5 is connected to the positive terminal of the battery connection, and the emitter E of switching transistor V5 is connected to the positive terminal of the power supply connection. The collector C of switching transistor V6 is connected to the negative terminal of the battery connection, and the emitter E of switching transistor V6 is connected to the negative terminal of the power supply connection. The gate G of switching transistors V5 and V6 is connected to a control device (not shown in the figure) to control the voltage between the gate G and the emitter E. When the voltage between the gate G and the emitter E is greater than the turn-on voltage, the IGBT is turned on, and the power supply device charges the power battery 10 through the DC charging interface 31.

[0121] When the power supply device charges the power battery 10 through the DC charging interface 31, the battery flow is as follows: Figure 7 The direction of the middle arrow. Current flows out from the positive terminal of the power battery 10, passes through the switching transistor V5 and flows into the positive terminal of the power supply device. Current flows out from the negative terminal of the power supply device, passes through the switching transistor V6 and flows into the negative terminal of the power battery 10, forming a charging circuit.

[0122] In one embodiment, the powertrain 20 includes a motor 22, a motor controller 21, and a DC charging device 30 as described in any of the above embodiments. The motor controller 21 is used to connect or disconnect the discharge circuit between the power battery 10 and the motor 22.

[0123] In this embodiment, the motor controller 21 is used to connect or disconnect the discharge circuit between the power battery 10 and the motor 22. For example, if the temperature of the power battery 10 is lower than a preset temperature, and considering that the charging power is too low or even impossible to charge when the temperature of the power battery 10 is too low, the power battery 10 is not suitable for charging. The motor controller 21 controls the connection of the discharge circuit between the power battery 10 and the motor 22. During the charging and discharging process of the power battery 10, the current generates heat on the internal resistance of the power battery 10, thereby heating the power battery 10.

[0124] As the power battery 10 continues to heat up, its temperature gradually increases. When the temperature of the power battery 10 is greater than or equal to a preset temperature, it is ready for charging. The motor controller 21 controls the disconnection of the discharge circuit between the power battery 10 and the motor 22 to prevent the power battery 10 from overheating. Furthermore, when the power battery 10 is ready for charging, the switch module 32 connects the positive and negative terminals of the power supply device and the power battery to form a charging circuit, thereby charging the power battery 10 and improving charging efficiency.

[0125] In this embodiment, the motor controller 21 is used to connect or disconnect the discharge circuit between the power battery 10 and the motor 22. In response to the power battery 10's temperature being lower than a preset temperature, the motor controller 21 controls the discharge circuit to be connected to heat the power battery 10, which helps improve the charging efficiency of the power battery 10. As the temperature of the power battery 10 increases, in response to the power battery 10's temperature being greater than or equal to the preset temperature, the motor controller 21 controls the discharge circuit to be disconnected to prevent the power battery 10 from overheating.

[0126] In one embodiment, the motor controller 21 is configured to turn on the discharge circuit in response to the switching module 32 disconnecting the charging circuit.

[0127] In one embodiment, the motor controller 21 is configured to disconnect the discharge circuit in response to the discharge circuit being on for a duration greater than or equal to a preset duration.

[0128] In this embodiment, the switch module 32 disconnects the charging circuit, indicating that it is not suitable to charge the power battery 10 at this time. This could be because the temperature of the power battery 10 is too low, or it could be because the electric vehicle needs to be operated. If the charging circuit is disconnected due to the low temperature of the power battery 10, the motor controller 21 responds to the switch module 32 disconnecting the charging circuit and conducts the discharge circuit to heat the power battery 10. This can prevent the charging power from being too low or even unable to be charged when the temperature of the power battery 10 is too low.

[0129] In this embodiment, the discharge circuit is activated, and the motor controller 21 drives the motor 22 to continuously heat the power battery 10. As the discharge circuit is activated, the temperature of the power battery 10 continuously rises. When the activation duration of the discharge circuit is greater than or equal to a preset duration, the power battery 10 is ready for charging. In response to the activation duration of the discharge circuit being greater than or equal to the preset duration, the motor controller 21 disconnects the discharge circuit to stop heating the power battery 10, thus preventing the power battery 10 from overheating and affecting its lifespan.

[0130] In one embodiment, the motor controller 21 includes a control circuit and an inverter circuit. The inverter circuit includes three bridge arm circuits. The two ends of each bridge arm are used to connect to the positive and negative terminals of the power battery, respectively. The midpoints of the three bridge arm circuits are used to connect to one phase winding of the motor 22.

[0131] The control circuit controls the upper bridge arm switch of one bridge arm to turn on and controls the lower bridge arm switch of the other bridge arm to turn on, while the motor controller 21 turns on the discharge circuit.

[0132] The control circuit keeps the upper and lower bridge arm switches of multiple bridge arms open, and the motor controller 21 disconnects the discharge circuit.

[0133] The control circuit in this embodiment can be as described above. Figure 3 The control circuit 34 in the DC charging device 30 can also be the control circuit in the motor controller 21, without limitation.

[0134] In this embodiment, when the temperature of the power battery 10 is less than or equal to a preset temperature, continuous charging of the power battery 10 will result in severe capacity decay, low charging power, or even failure to charge. Therefore, the control circuit controls the switching transistor to turn on or off to heat the power battery 10.

[0135] In the embodiments of this application, the bridge arm circuit includes one or more of various types of switching transistors such as MOSFET and IGBT, and there is no specific limitation on this.

[0136] Figure 8 This is a schematic diagram of a powertrain provided in an embodiment of this application. (Reference) Figure 8 The motor controller 21 includes six switching transistors (Q1, Q2, Q3, Q4, Q5, and Q6), and the control terminals of these six transistors are all connected to the control circuit 210. The control circuit 210 controls the on / off state of these six switching transistors to keep the power battery 10 in a cyclic discharge and charge state to heat the power battery 10. The following text, in conjunction with... Figure 9 and Figure 10 Please provide a detailed explanation.

[0137] Figure 9 This is a schematic diagram of a discharge circuit provided in an embodiment of this application. Figure 10 This is a schematic diagram of a charging circuit provided in an embodiment of this application. Wherein, Figure 9 and Figure 10 The power battery 10 is equivalent to a battery pack and internal resistance.

[0138] Figure 9 In the middle, the control circuit 210 controls the switching transistors Q1, Q4, and Q6 to conduct, thereby forming a discharge circuit between the power battery 10, Q1, Q4, Q6, and the motor 30. Figure 10 In the middle, the control circuit 210 controls the switching transistors Q2, Q3, and Q5 to conduct, thereby forming a charging circuit between the power battery 10, Q2, Q3, Q5, and the motor 30.

[0139] refer to Figure 9 The battery pack outputs energy, and the current flows out from the positive terminal, through the internal resistance and the switching transistor Q1, into the motor from the U phase, and then flows out from the motor's V and W phases respectively. After flowing out from the motor's V phase, the current flows into the battery's negative terminal through the switching transistor Q4, and after flowing out from the motor's W phase, it flows into the battery's negative terminal through the switching transistor Q6, thus forming a battery discharge circuit. During this process, the motor stores energy. Moreover, during the battery discharge process, the current flowing through the battery's internal resistance generates heat, thereby heating the power battery 10.

[0140] refer to Figure 10 The motor releases energy, and current flows out from phases V and W. The current flowing from phase V passes through switch Q3 and into the battery, while the current flowing from phase W passes through switch Q5 and into the battery. After passing through the internal resistance and the battery pack, the current flows through switch Q2 into phase U of the motor, and then flows out from phases V and W respectively, thus forming a battery charging circuit. During this process, the battery stores energy. Furthermore, during battery charging, the current flowing through the battery's internal resistance generates heat, thereby heating the power battery 10.

[0141] In summary, during the charging and discharging process, current flows through the internal resistance of the power battery 10, and the current continuously generates heat on the internal resistance of the power battery 10. Therefore, the power battery 10 is constantly in a heated state.

[0142] It should be noted that, Figure 9 and Figure 10 The discharge and charging circuits shown are merely illustrative examples. In some possible implementations, the control circuit 210 controls different switching transistors to turn on or off to heat the power battery 10.

[0143] For example, control circuit 210 controls switches Q2, Q3, and Q6 to conduct, thereby forming a discharge circuit between power battery 10, Q2, Q3, Q6, and motor 30. Control circuit 210 controls switches Q1, Q4, and Q5 to conduct, thereby forming a charging circuit between battery 10, Q1, Q4, Q5, and motor 30.

[0144] In this embodiment, the control circuit controls the upper bridge arm switch of one bridge arm and the lower bridge arm switch of another bridge arm to conduct, and the motor controller conducts the discharge circuit to heat the power battery 10, which helps to improve the charging efficiency of the power battery 10. Alternatively, the control circuit controls the upper and lower bridge arm switches of multiple bridge arms to remain open, and the motor controller disconnects the discharge circuit to stop heating the power battery 10, preventing the power battery 10 from overheating and affecting its lifespan. When the motor controller 21 controls the conduction or disconnection of the discharge circuit, the control circuit can also control the disconnection of the charging circuit, thus heating the power battery 10 while preventing the AC power generated by the motor operation due to the control circuit controlling the switching of the switches from entering the power supply device and causing damage.

[0145] This application also provides an electric vehicle, which includes a power battery 10, a vehicle controller, a motor controller 21, a motor 22, and a DC charging device 30 in any of the above embodiments.

[0146] The power battery 10 includes a battery management unit, which is used to detect the temperature of the power battery 10.

[0147] The vehicle controller is used to control at least one of the DC charging device 30 or the motor controller 21 based on a comparison between the temperature of the power battery 10 and a preset temperature.

[0148] In this embodiment, in response to the temperature of the power battery 10 being lower than a preset temperature, the vehicle controller controls the motor controller 21 to open the discharge circuit between the power battery 10 and the motor 22 to heat the power battery 10. This prevents the power battery 10 from being charged when its temperature is too low, which would result in low charging power or even no charging at all. Simultaneously, because the vehicle controller controls the DC charging device 30 to output a preset DC voltage in response to the power battery 10's temperature being lower than the preset temperature, it also prevents the power supply device from alarming for charging abnormalities due to a disconnected charging circuit. Furthermore, this reduces user operations and improves the user experience.

[0149] As the temperature of the power battery 10 gradually rises, in response to the power battery 10's temperature exceeding or equaling a preset temperature, the vehicle controller controls the motor controller 21 to disconnect the discharge circuit between the power battery 10 and the motor 22, preventing the power battery 10 from overheating and affecting its lifespan. Simultaneously, because the vehicle controller controls the DC charging device 30 to stop outputting a preset DC voltage in response to the power battery 10's temperature exceeding or equaling the preset temperature, it also prevents the DC charging device 30 from continuously outputting the preset DC voltage converted from the power battery 10 to the positive and negative terminals of the power supply device, thus protecting the power battery 10 from a continuous decrease in voltage.

[0150] To better understand the solution in this application, such as Figure 11 The diagram shown is a schematic of a battery low-temperature heating method provided in an embodiment of this application, which includes steps 710 to 720.

[0151] 710, Electric vehicle connected to charging station detected.

[0152] 712. Is the temperature of the electric vehicle's power battery lower than the preset temperature?

[0153] If yes, proceed to step 714; otherwise, proceed to step 720.

[0154] 714, the DC-DC module is working, outputting a preset DC voltage; the charging circuit is disconnected, and the power battery is charged, discharged, and heated.

[0155] The DC-DC module is the DC voltage conversion module 33 in the above embodiment.

[0156] 716. Whether the power battery temperature is greater than or equal to the preset temperature, or whether the charging and discharging time of the power battery is greater than or equal to the preset time.

[0157] If yes, proceed to step 718; otherwise, return to step 712.

[0158] 718, DC-DC module and powertrain stop working, charging circuit is connected.

[0159] In step 718, the DC-DC module may continue to operate without restriction.

[0160] 720, entering normal fast charging mode.

[0161] In this embodiment, after detecting that the electric vehicle is connected to the charging pile, it first determines whether the temperature of the electric vehicle's power battery is lower than a preset temperature. If not, fast charging begins. If so, since the power battery temperature is lower than the preset temperature, it is not suitable to directly charge the power battery. Therefore, the DC-DC module can be activated to output a preset DC voltage to the charging pile, creating a deceptive connection between the charging pile and the electric vehicle. Simultaneously, the charging pile's charging of the battery is paused, the charging circuit is disconnected, and the motor controller controls the heating of the power battery. When the power battery temperature is greater than or equal to the preset temperature, or the battery charging and discharging time is greater than or equal to the preset time, the DC-DC module and powertrain operation are stopped, and the charging circuit is activated to enter normal fast charging mode.

[0162] It should be understood that the specific examples in the above embodiments are only for helping those skilled in the art to better understand the embodiments of this application, and are not intended to limit the scope of the embodiments of this application. It should also be understood that the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0163] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A DC charging device, characterized in that, The DC charging device is used to charge the power battery of an electric vehicle. The DC charging device includes a DC charging interface, a switching module, and a DC voltage conversion module, wherein: The DC charging interface is used to connect the positive and negative terminals of the power supply device and the positive and negative terminals of the power battery to form a charging circuit; The switching module is used to turn the charging circuit on or off. The DC voltage conversion module is used to output a preset DC voltage to the positive and negative terminals of the power supply device; wherein The switching module is specifically used for: In response to the DC voltage conversion module outputting the preset DC voltage, the charging circuit is disconnected; The DC voltage conversion module is specifically used for: In response to the switching module turning on the charging circuit, the output of the preset DC voltage is stopped.

2. The DC charging device according to claim 1, characterized in that, The switching module is used for: In response to the fact that the temperature of the power battery is lower than a preset temperature, the charging circuit is disconnected; In response to the temperature of the power battery being greater than or equal to the preset temperature, the charging circuit is turned on.

3. The DC charging device according to claim 1, characterized in that, The DC voltage conversion module is used for: In response to the fact that the temperature of the power battery is lower than the preset temperature, the preset DC voltage is output; In response to the temperature of the power battery being greater than or equal to the preset temperature, the output of the preset DC voltage is stopped.

4. The DC charging device according to claim 1, characterized in that, The DC charging device includes a control circuit, which is used for: In response to the DC charging interface being connected to the positive and negative terminals of the power supply device, based on the comparison result between the temperature of the power battery and the preset temperature, the DC voltage conversion module is controlled to output or stop outputting the preset DC voltage, and the switching module is controlled to turn on or off the charging circuit. In response to the DC charging interface not being connected to the positive and negative terminals of the power supply device, the DC voltage conversion module is controlled to stop outputting the preset DC voltage.

5. The DC charging device according to claim 4, characterized in that, The electric vehicle includes a motor controller and a motor. The motor controller is used to connect or disconnect the discharge circuit between the power battery and the motor. The control circuit is used for: In response to the fact that the temperature of the power battery is lower than the preset temperature, the motor controller is controlled to turn on the discharge circuit; In response to the temperature of the power battery being greater than or equal to the preset temperature, the motor controller is controlled to disconnect the discharge circuit.

6. The DC charging device according to any one of claims 1-5, characterized in that, The DC charging interface includes two battery connection terminals and two power connection terminals. The two battery connection terminals are used to connect to the positive and negative terminals of the power battery, respectively, and the two power connection terminals are used to connect to the positive and negative terminals of the power supply device, respectively. The DC voltage conversion module receives power from the power battery through the two battery connection terminals, and outputs the preset DC voltage through the two power connection terminals.

7. The DC charging device according to claim 6, characterized in that, The DC-DC voltage conversion module includes diodes, resistors, capacitors, and controllable switches, wherein: The anode of the diode is connected to a battery connection terminal, and the cathode of the diode is connected to a power connection terminal through the resistor and the controllable switch. The battery connection terminal is used to connect to the positive terminal of the power battery, and the power connection terminal is used to connect to the positive terminal of the power supply device. One end of the capacitor is connected between the resistor and the switch, and the other end of the capacitor is connected to another battery connection terminal and another power connection terminal. The other battery connection terminal is used to connect to the negative terminal of the power battery, and the other power connection terminal is used to connect to the negative terminal of the power supply device.

8. The DC charging device according to claim 6, characterized in that, The switch module includes two additional controllable switches, wherein: One of the controllable switches is used to turn on or off the connection between one of the power supply terminals and one of the battery terminals; Another controllable switch is used to connect or disconnect the connection between another power supply terminal and another battery terminal.

9. A powertrain, characterized in that, The powertrain includes a motor, a motor controller, and a DC charging device as described in any one of claims 1-8, wherein the motor controller is used to connect or disconnect the discharge circuit between the power battery and the motor.

10. The powertrain according to claim 9, characterized in that, The motor controller is used for: In response to the switching module disconnecting the charging circuit, the discharging circuit is turned on.

11. The powertrain according to claim 9 or 10, characterized in that, The motor controller is used for: In response to the discharge circuit being on for a duration greater than or equal to a preset duration, the discharge circuit is disconnected.

12. The powertrain according to any one of claims 9-11, characterized in that, The motor controller includes a control circuit and an inverter circuit. The inverter circuit includes three bridge arm circuits. The two ends of each bridge arm are respectively used to connect to the positive and negative terminals of the power battery. The midpoints of the three bridge arm circuits are respectively used to connect to one phase winding of the motor. The control circuit controls the upper bridge arm switch of one of the bridge arms to turn on and controls the lower bridge arm switch of the other bridge arm to turn on, and the motor controller turns on the discharge circuit. The control circuit keeps the upper and lower bridge arm switches of the plurality of bridge arms open, and the motor controller disconnects the discharge circuit.

13. An electric vehicle, characterized in that, The electric vehicle includes a power battery, a vehicle controller, a motor controller, a motor, and a DC charging device as described in any one of claims 1-8, wherein: The power battery includes a battery management unit, which is used to detect the temperature of the power battery. The vehicle controller is used to control at least one of the DC charging device or the motor controller based on a comparison between the temperature of the power battery and a preset temperature.

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