Circuit, System and Method for Battery Heating

Abstract

The present application discloses a circuit, a system and a method for battery heating, which relate to the field of vehicles. The specific implementation solution is as follows: at least one driving resistor array, which includes at least two parallel branches, each parallel branch includes a resistor and a switch connected in series, or each of at least two parallel branches except one parallel branch only includes a resistor includes a resistor and a switch connected in series; among the two ends where at least two parallel branches are connected in parallel, one end is used to access a driving signal, and the other end is used to be connected to the gate of an insulated gate bipolar transistor in the electric drive system of the vehicle; and the detection end of the heating control module is used to be connected to a device for detecting the temperature of the power battery of the vehicle, and the control end is respectively connected to at least one driving resistor array to control the opening and closing of the switch. The present application can change the gate input resistance of the IGBT device in the electric drive system to change its loss and adjust the efficiency of battery heating.

Description

Technical Field

[0001] This application relates to the technical field of vehicles, and particularly to circuits, systems, and methods for heating vehicle batteries. Background Art

[0002] The working performance of a vehicle's power battery is greatly affected by its temperature, and the working temperature corresponding to its best performance is about 25°C. In a low-temperature environment, the charge and discharge performance of the power battery will be greatly limited. Especially when the battery temperature reaches below -20°C, its discharge performance is only about 10% of that at normal temperature, and it even does not have the ability to charge. Therefore, in order to maintain the necessary charge and discharge performance, when the battery temperature drops to a certain value, it is necessary to heat the power battery. When the charge and discharge performance of the power battery meets the requirements of the entire vehicle, the heating can be stopped.

[0003] Currently, the common heating technologies for electric vehicles are mainly reflected in the following two directions:

[0004] 1. Using a high-voltage PTC (Positive Temperature Coefficient) heater. The high-voltage PTC is currently the most mainstream heating element. It is made of a PTC ceramic heating element and an aluminum tube, with high heat conversion efficiency, but it will increase the cost of the entire vehicle, and the vehicle cannot fully utilize its own components to generate heat energy.

[0005] 2. Using a heat pump. A heat pump is a device that transfers the heat energy of a low-temperature heat source to a high-temperature heat source. By swapping the functions of the evaporator and the condenser and changing the direction of heat transfer, the coefficient of performance of the heat energy within a specific temperature range is high. This is currently the mainstream direction of electric vehicle thermal management applications. This includes a method of using the electric drive system in the vehicle to generate heat to heat the battery.

[0006] Currently, there are the following two ways to heat the battery using the electric drive system:

[0007] Method 1: Battery self-heating technology. The motor controller is used to control the motor's inductor to repeatedly perform "energy storage - energy release" operations, thereby generating high-frequency alternating current on the DC bus and generating heating power on the battery internal resistance to heat the battery.

[0008] Method 2: Heating using the motor stall mode. When the battery needs to be heated, the motor is controlled to enter the stall mode, and the heat generated by the motor and the motor controller in this mode is used to heat the battery.

[0009] The motor controller in the above two methods controls the switching of 6 IGBT devices by a PWM signal to convert DC into AC and then drive the motor to rotate and work. Refer to Figure 1 ,Figure 1 It is a topological circuit diagram of an electric drive system in a vehicle.

[0010] However, the above-mentioned first method cannot fully utilize the heat of heating elements such as motors and IGBTs to heat the battery, and the resource utilization rate of heating is still relatively low. In the above-mentioned second method, since it is a normal drive circuit during the heating process, the heat generation of the IGBT element is not high when heating the battery, and it cannot provide enough energy to heat the battery. SUMMARY OF THE INVENTION

[0011] The present application provides a circuit, a system and a method for battery heating to solve or alleviate one or more technical problems in the prior art.

[0012] According to one aspect of the present application, a circuit for battery heating is provided, including:

[0013] At least one driving resistor array, the driving resistor array includes at least two parallel branches, each of the parallel branches includes a resistor and a switch connected in series, or each of the at least two parallel branches except one parallel branch includes only a resistor includes a resistor and a switch connected in series; at one of the two ends of the parallel connection of the at least two parallel branches, one end is used to access a driving signal, and the other end is used to connect to the gate of an insulated gate bipolar transistor in the electric drive system of the vehicle; and

[0014] A heating control module, including a detection end and a control end, the detection end is used to connect to a device for detecting the temperature of the power battery of the vehicle, and the control end is respectively connected to the controlled ends of the switches in the at least one driving resistor array to control the opening and closing of the switches.

[0015] In an embodiment, it further includes an optocoupler isolation module connected between the control end of the heating control module and the controlled ends of the switches in the at least one driving resistor array, and the optocoupler isolation module is used to isolate and amplify the control signal output by the heating control module.

[0016] In an embodiment, the driving resistor array includes three parallel branches, wherein the first parallel branch includes a first resistor and a first switch connected in series, the second parallel branch includes a second resistor and a second switch connected in series, and the third parallel branch includes a third resistor.

[0017] In an embodiment, the number of the driving resistor arrays is six, and the six driving resistor arrays are respectively connected to six insulated gate bipolar transistors in the electric drive system.

[0018] In an embodiment, the structures of the six driving resistor arrays are the same.

[0019] According to another aspect of the present application, there is provided a battery heating system, comprising:

[0020] a motor;

[0021] an electric drive system, which includes a plurality of insulated gate bipolar transistors; and

[0022] a battery heating circuit according to any embodiment of the present application, at least one drive resistor array in the circuit is respectively connected to the gates of at least one of the insulated gate bipolar transistors in the electric drive system;

[0023] wherein, the battery heating circuit is configured to receive a drive signal and drive the electric drive system according to the drive signal, so that the electric drive system converts the direct current input to the electric drive system into alternating current and outputs the alternating current to the motor to drive the motor to rotate.

[0024] According to another aspect of the present application, there is provided a method for battery heating, which is executed by a heating control module, and the method includes:

[0025] Obtaining the temperature of the power battery of the vehicle;

[0026] According to the obtained temperature, outputting a control signal to the controlled terminals of the switches of at least one drive resistor array to control the opening and closing of the switches, the drive resistor array includes at least two parallel branches, each of the parallel branches includes a resistor and a switch connected in series, or each of the at least two parallel branches except one parallel branch includes only a resistor includes a resistor and a switch connected in series; at both ends of the parallel connection of the at least two parallel branches, one end is used to access the drive signal, and the other end is used to be connected to the gate of the insulated gate bipolar transistor in the electric drive system of the vehicle.

[0027] In one embodiment, the drive resistor array includes three parallel branches, wherein, the first parallel branch includes a first resistor and a first switch connected in series, the second parallel branch includes a second resistor and a second switch connected in series, and the third parallel branch includes a third resistor. The outputting a control signal to the controlled terminals of the switches of at least one drive battery array according to the obtained temperature includes:

[0028] If the obtained temperature is less than the first temperature threshold, outputting a first control signal to the drive resistor array to disconnect the first switch and the second switch;

[0029] If the obtained temperature is greater than the first temperature threshold but less than the second temperature threshold, outputting a second control signal to the drive resistor array to disconnect one of the first switch and the second switch; and

[0030] If the acquired temperature is greater than the second temperature threshold, output a third control signal to the driving resistor array to close the first switch and the second switch.

[0031] In one implementation, the outputting a control signal to the control terminals of the switches of at least one driving battery array according to the acquired temperature includes:

[0032] If the acquired temperature is less than the first temperature threshold, output a first control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the first parallel resistance;

[0033] If the acquired temperature is greater than the first temperature threshold but less than the second temperature threshold, output a second control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the second parallel resistance;

[0034] If the acquired temperature is greater than the second temperature threshold, output a third control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the third parallel resistance;

[0035] Wherein, the first parallel resistance is greater than the second parallel resistance, and the second parallel resistance is greater than the third parallel resistance.

[0036] According to the embodiments of the present application, the circuit for battery heating can change the circuit structure of the electric drive system. The battery heating system changes the loss situation of the electric drive system according to the temperature change of the power battery of the vehicle, so that when using the motor to heat the power battery in a low-temperature state, the electric drive system can also be in a high-loss mode to generate heat for heating the power battery and improve the heating efficiency.

[0037] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become easily understood through the following description. Description of the Drawings

[0038] In the drawings, unless otherwise specified, the same reference numerals throughout the several drawings denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0039] Figure 1 is the topological circuit diagram of the electric drive system in the vehicle;

[0040] Figure 2 is the structural schematic diagram of the circuit for battery heating provided by the embodiments of the present application;

[0041] Figure 3 is the turn-on transient waveform of the IGBT switching device according to an embodiment of the present application;

[0042] Figure 4 is a schematic diagram of the driving resistance and the loss of the switching device provided by an embodiment of the present application;

[0043] Figure 5 The present application provides a method for battery heating;

[0044] Figure 6 is an application schematic diagram according to an embodiment of the present application. Detailed implementation manners

[0045] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and descriptions are considered to be exemplary in nature rather than restrictive.

[0046] See Figure 1 , Figure 1Topological circuit diagram of an electric drive system in a vehicle. The electric drive system 100 generally includes six insulated gate bipolar transistors (IGBTs), namely, a first insulated gate bipolar transistor D1, a second insulated gate bipolar transistor D2, a third insulated gate bipolar transistor D3, a fourth insulated gate bipolar transistor D4, a fifth insulated gate bipolar transistor D5, and a sixth insulated gate bipolar transistor D6. The source of the first insulated gate bipolar transistor D1 is connected to the positive pole of the DC output terminal of the electric drive system, its drain is connected to the source of the second insulated gate bipolar transistor D2, and the drain of the second insulated gate bipolar transistor D2 is connected to the negative pole of the DC output terminal of the electric drive system. The source of the third insulated gate bipolar transistor D3 is connected to the positive pole of the DC output terminal of the electric drive system, its drain is connected to the source of the fourth insulated gate bipolar transistor D4, and the drain of the fourth insulated gate bipolar transistor D4 is connected to the negative pole of the DC output terminal of the electric drive system. The source of the fifth insulated gate bipolar transistor D5 is connected to the positive pole of the DC output terminal of the electric drive system, its drain is connected to the source of the sixth insulated gate bipolar transistor D6, and the drain of the sixth insulated gate bipolar transistor D6 is connected to the negative pole of the DC output terminal of the electric drive system. The connection between the drain of the first insulated gate bipolar transistor D1 and the source of the second insulated gate bipolar transistor D2, the connection between the drain of the third insulated gate bipolar transistor D3 and the source of the fourth insulated gate bipolar transistor D4, and the connection between the drain of the fifth insulated gate bipolar transistor D5 and the source of the sixth insulated gate bipolar transistor D6 are respectively connected to the three-phase power input terminal of the motor. A DC power supply is connected between the positive pole and the negative pole of the DC output terminal. The gates of the six insulated gate bipolar transistors are all connected to PWM drive signals. The PWM signal controls the opening and closing of the 6 IGBT devices, converts the DC input to the 6 IGBT devices into AC, and outputs the AC to the motor to supply power to the motor, thereby driving the motor to rotate. When the electric drive system normally drives the motor to work, generally in order to pursue a higher power conversion system, the lower the switching loss of the IGBT, the better. However, when using the heat generated by the motor to heat the power battery of the vehicle, the switching loss of the electric drive system is too low, resulting in low heating efficiency and failing to fully utilize the loss of the electric drive system to heat the power battery of the vehicle.

[0047] Therefore, a resistor R can be connected before connecting the PWM drive signal to the gates of the six insulated gate bipolar transistors G , which can improve the heating efficiency.

[0048] Exemplarily, the present application proposes a circuit for battery heating to represent the resistor R G , as Figure 2 shown. Figure 2 is a schematic structural diagram of the circuit for battery heating provided by an embodiment of the present application. The circuit R for battery heatingG It includes: at least one driving resistance array 310 and a heating control module 320. For example, it may include six driving resistance arrays, and each driving resistance array is correspondingly connected to the gate of each insulated gate bipolar transistor IGBT in the electric drive system. Again, for example, the structures of each driving resistance array may be the same.

[0049] The driving resistance array 310 may include at least two parallel branches. Each parallel branch in the array includes a resistor and a switch connected in series, or one of the parallel branches in the array only includes a resistor, and each of the other parallel branches includes a resistor and a switch connected in series. Among the two ends where all the parallel branches in the array are connected in parallel, one end is used to access the driving signal, and the other end is used to be connected to the gate of the insulated gate bipolar transistor in the vehicle's electric drive system. Thus, the driving resistance array changes the magnitude of the current of the PWM driving signal output to the gate of the insulated gate bipolar transistor in the electric drive system by changing the magnitude of the parallel resistors.

[0050] The heating control module 320 includes a detection end and a control end. The detection end is used to be connected to a device or system for detecting the temperature of the vehicle's power battery. There may be multiple control ends, which are respectively connected to the controlled ends of the switches in the driving resistance array one by one to control the opening and closing of each switch.

[0051] The resistor and the switch connected in series in the parallel branch may be just a resistor and a switch connected in series, or may be composed of multiple resistors and a switch connected in series, or may be composed of multiple resistors combined in series and parallel to form a resistor with a required resistance value and a switch connected in series.

[0052] The above-mentioned device or system for detecting the temperature of the vehicle's power battery may be the vehicle's thermal management system, and this heat pipe system is connected to the detection end of the heating control module. The thermal management system provides the heating requirement to the heating control module, and the heating control module judges the driving loss mode that needs to be entered according to the requirement, and thus issues corresponding control signals to the driving resistance array according to this driving loss mode to control the opening and closing of the switches in the array. Among them, the more resistors incorporated into the electric drive system, the smaller the total resistance value, the larger the driving current, the faster the switching speed of the IGBT switching device in the electric drive system, and the lower the generated loss. And the fewer resistors incorporated into the electric drive system, the larger the total resistance value, the larger the driving current, the slower the switching speed of the IGBT switching device in the electric drive system, and the higher the generated loss.

[0053] As Figure 3 shown, it shows the turn-on transient waveform of the IGBT switching device in the embodiment of the present application.

[0054] I gRepresents the drive current, outputs to the gate of the IGBT, i.e., charges the input capacitance of the IGBT.

[0055] V ge Represents the drive voltage. After this drive voltage is greater than V ge-th , the IGBT gradually turns on, and the waveform change is affected by I g , and V ge affects the switching speed of the IGBT.

[0056] V ce Represents the voltage drop between the source and the drain.

[0057] Among them, the switching loss is reflected in the product of V ce and V ge during the turn-on process, that is, the integral of the instantaneous dissipation power. Therefore, generally, the slower the switching process, the greater the loss.

[0058] As Figure 4 shown, it exemplifies the relationship between the magnitude of the drive resistance of the gate of the IGBT switching device and the loss of this switch.

[0059] In some embodiments, the circuit can amplify the control signal. As Figure 2 shown, the circuit for battery heating may further include an opto-isolation module 330 connected between the control terminal of the heating control module and the controlled terminals of each switch in at least one drive resistance array. The opto-isolation module 330 is used to isolate and amplify the control signal output by the heating control module.

[0060] In some embodiments, as Figure 2 shown, the drive resistance array 310 may include three parallel branches. The first parallel branch includes a first resistor R1 and a first switch K1 connected in series. The second parallel branch includes a second resistor R2 and a second switch K2 connected in series. The third parallel branch includes a third resistor R3.

[0061] The heating control module R G may be provided with two control terminals, which are respectively connected to the controlled terminals of the first switch K1 and the second switch K2 to control the opening and closing of the first switch K1 and the second switch K2.

[0062] Exemplarily, if the temperature of the power battery of the vehicle is very low, the first switch K1 and the second switch K2 can be disconnected, so that the electric drive system 100 enters the high-loss mode, and the loss generated by the electric drive system 100 can heat the power battery.

[0063] Combined with Figure 1 and Figure 2 , the present application provides a battery heating system, including: a motor 200, an electric drive system 100, and a circuit R for battery heatingG The battery heating circuit includes a driving resistor array 310 and a heating control module 320. The driving resistor array 310 may include at least two parallel branches. Each parallel branch in the array includes a resistor and a switch connected in series, or one of the parallel branches in the array only includes a resistor, and each of the other parallel branches includes a resistor and a switch connected in series. Among the two ends where all the parallel branches in the array are connected in parallel, one end is used to access the driving signal, and the other end is used to connect to the gate of the insulated gate bipolar transistor in the electric drive system of the vehicle. Exemplarily, in the battery heating circuit, there are six driving resistor arrays, and there are six IGBTs in the electric drive system. Then, the six driving resistor arrays and the six IGBTs are connected one by one, with one driving resistor array connected to one IGBT.

[0064] The driving signal is input to the gate of the IGBT in the electric drive system through the driving resistor array to drive the IGBT to conduct or turn off. Then, the direct current input to the electric drive system is converted into alternating current as the IGBT conducts and turns off, and this alternating current is output to the motor. For the connection relationship between the electric drive system and the motor, reference can be made to Figure 1 and the foregoing description of the electric drive system.

[0065] The heating control module includes a detection end and a control end. The detection end is used to connect to a device or system for detecting the temperature of the power battery of the vehicle. There may be multiple control ends, which are respectively connected to the controlled ends of the switches in the driving resistor array one by one to control the opening and closing of each switch. The heating control module can adjust the total resistance value of the driving resistor array according to the change of the power battery of the vehicle, that is, adjust the magnitude of the driving current when the driving signal is input to the gate, so as to adjust the loss of the IGBT to heat the power battery.

[0066] See Figure 5 This application provides a method for heating a battery, which is executed by the heating control module. The method may include the following steps:

[0067] Step S100: Obtain the temperature of the power battery of the vehicle. The thermal management system of the vehicle can detect the temperature of the power battery and the surrounding environment of the battery. If the temperature is too low, the corresponding temperature can be sent to the heating control module. Of course, the thermal management system can send the temperature to the heating control module in real time, and the heating control module can generate corresponding control instructions or control signals for each switch according to the obtained temperature.

[0068] Step S200: According to the acquired temperature, output a control signal to the controlled terminals of the switches of at least one driving resistor array to control the opening and closing of the switches. The driving resistor array includes at least two parallel branches. Each parallel branch includes a resistor and a switch connected in series, or each of at least two parallel branches except one parallel branch that only includes a resistor includes a resistor and a switch connected in series. At both ends of the parallel connection of the above at least two parallel branches, one end is used to access the driving signal, and the other end is used to connect to the gate of the insulated gate bipolar transistor in the electric drive system of the vehicle.

[0069] In one embodiment, the driving resistor array may include three parallel branches. Among them, the first parallel branch includes a first resistor and a first switch connected in series. The second parallel branch includes a second resistor and a second switch connected in series. The third parallel branch includes a third resistor. As Figure 6 shown, the process of outputting a control signal to the controlled terminals of the switches of at least one driving battery array according to the acquired temperature may include at least one of the following situations:

[0070] If the acquired temperature T is less than the first temperature threshold T1, output a first control signal to the driving resistor array to open the first switch and the second switch. At this time, the total resistance value of the driving resistor array is the largest, and the IGBT is in a high-loss mode. When the electric drive system heats the battery by driving the motor, the generated heat is the highest, and the battery heating efficiency is the highest.

[0071] If the acquired temperature T is greater than the first temperature threshold T1 but less than the second temperature threshold T2, output a second control signal to the driving resistor array to open one of the first switch and the second switch. At this time, the total resistance value of the driving resistor is in the middle range, and the IGBT is in a medium-loss mode. When the electric drive system heats the battery by driving the motor, the generated heat is in the middle range, and the battery heating efficiency is relatively high.

[0072] If the acquired temperature T is greater than the second temperature threshold T2, output a third control signal to the driving resistor array to close the first switch and the second switch. At this time, the total resistance value of the driving resistor is in the low-resistance range, and the IGBT is in a low-loss mode. When the electric drive system heats the battery by driving the motor, the generated heat is the lowest, and the battery heating efficiency is the lowest.

[0073] Of course, multiple temperature thresholds and more parallel branches can also be set to generate no less than the above three loss modes.

[0074] In one embodiment, the process of outputting a control signal to the controlled terminals of the switches of at least one driving battery array according to the acquired temperature may include at least one of the following situations:

[0075] If the acquired temperature is less than the first temperature threshold, output a first control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the first parallel resistance. Each switch of the driving resistor array can be selected to be closed or open according to the first control signal, and the total parallel resistance of the driving resistor array is made to be the first parallel resistance.

[0076] If the acquired temperature is greater than the first temperature threshold but less than the second temperature threshold, output a second control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the second parallel resistance. As above, the principle thereof will not be described again.

[0077] If the acquired temperature is greater than the second temperature threshold, output a third control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the third parallel resistance. As above, the principle thereof will not be described again.

[0078] Wherein, the first parallel resistance is greater than the second parallel resistance, and the second parallel resistance is greater than the third parallel resistance.

[0079] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps recited in this application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions disclosed in this application can be achieved, and no limitation is made herein.

[0080] The above specific embodiments do not constitute a limitation on the protection scope of this application. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A battery heating circuit, characterized in that, Comprising: At least one driving resistor array, the driving resistor array includes at least two parallel branches, each of the parallel branches includes a resistor and a switch connected in series, or each of the at least two parallel branches except one parallel branch that only includes a resistor includes a resistor and a switch connected in series; at one of the two ends of the parallel connection of the at least two parallel branches, one end is used to access a driving signal, and the other end is used to connect to the gate of an insulated gate bipolar transistor in the electric drive system of the vehicle; And A heating control module, including a detection end and a control end, the detection end is used to connect to a device for detecting the temperature of the power battery of the vehicle, and the control end is respectively connected to the controlled ends of the switches in the at least one driving resistor array to control the opening and closing of the switches; The driving signal is a PWM signal for controlling the opening and closing of the insulated gate bipolar transistor.

2. The circuit according to claim 1, wherein It further includes an optocoupler isolation module connected between the control end of the heating control module and the controlled ends of the switches in the at least one driving resistor array, and the optocoupler isolation module is used to isolate and amplify the control signal output by the heating control module.

3. The circuit according to claim 1, characterized in that, The driving resistor array includes three parallel branches, wherein the first parallel branch includes a first resistor and a first switch connected in series, the second parallel branch includes a second resistor and a second switch connected in series, and the third parallel branch includes a third resistor.

4. The circuit according to claim 1, characterized in that, The number of the driving resistor arrays is six, and these six driving resistor arrays are respectively connected to six insulated gate bipolar transistors in the electric drive system.

5. The circuit according to claim 4, wherein The structures of the six driving resistor arrays are the same.

6. A battery heating system, characterized in that, Comprising: A motor; An electric drive system, which includes a plurality of insulated gate bipolar transistors; And The battery heating circuit according to any one of claims 1 to 5, at least one driving resistor array in the circuit is respectively connected to the gate of at least one of the insulated gate bipolar transistors in the electric drive system; Wherein, the battery heating circuit is used to receive a driving signal and drive the electric drive system according to the driving signal, so that the electric drive system converts the direct current input to the electric drive system into alternating current and outputs the alternating current to the motor to drive the motor to rotate.

7. A method for heating a battery, characterized in that, Executed by the heating control module, the method includes: Obtaining the temperature of the power battery of the vehicle; According to the obtained temperature, outputting a control signal to the controlled ends of the switches in at least one driving resistor array to control the opening and closing of the switches, the driving resistor array includes at least two parallel branches, each of the parallel branches includes a resistor and a switch connected in series, or each of the at least two parallel branches except one parallel branch that only includes a resistor includes a resistor and a switch connected in series; at one of the two ends of the parallel connection of the at least two parallel branches, one end is used to access a driving signal, and the other end is used to connect to the gate of an insulated gate bipolar transistor in the electric drive system of the vehicle; the driving signal is a PWM signal for controlling the opening and closing of the insulated gate bipolar transistor.

8. The method according to claim 7, characterized in that, The driving resistor array includes three parallel branches. Among them, the first parallel branch includes a first resistor and a first switch connected in series, the second parallel branch includes a second resistor and a second switch connected in series, and the third parallel branch includes a third resistor. The output of the control signal to the controlled terminals of the switches of at least one driving battery array according to the acquired temperature includes: If the acquired temperature is less than the first temperature threshold, output a first control signal to the driving resistor array to disconnect the first switch and the second switch; If the acquired temperature is greater than the first temperature threshold but less than the second temperature threshold, output a second control signal to the driving resistor array to disconnect one of the first switch and the second switch; and If the acquired temperature is greater than the second temperature threshold, output a third control signal to the driving resistor array to close the first switch and the second switch.

9. The method according to claim 7, characterized in that, The output of the control signal to the controlled terminals of the switches of at least one driving battery array according to the acquired temperature includes: If the acquired temperature is less than the first temperature threshold, output a first control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the first parallel resistance; If the acquired temperature is greater than the first temperature threshold but less than the second temperature threshold, output a second control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the second parallel resistance; If the acquired temperature is greater than the second temperature threshold, output a third control signal to the driving resistor array, and the total parallel resistance of the driving resistor array is the third parallel resistance; Wherein, the first parallel resistance is greater than the second parallel resistance, and the second parallel resistance is greater than the third parallel resistance.

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