Battery pack heating method, device and equipment based on low-temperature driving and storage medium

Abstract

The invention discloses a battery pack heating method, device and equipment based on low-temperature driving and a storage medium, relates to the technical field of battery pack heat management, and discloses the battery pack heating method based on low-temperature driving. Obtaining the target temperature of the battery pack, the state of charge of the battery pack and a preset state of charge switching threshold; determining a target heating control logic according to the state of charge of the battery pack and the preset state of charge switching threshold; and heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating based on low-temperature driving. The effects of reducing the heating power consumption of the battery pack and improving the low-temperature road cruising ability of the pure electric vehicle are achieved, and meanwhile normal power output of the battery pack in the low-temperature and low-charge state is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery pack thermal management, in particular to a battery pack heating method and device based on low-temperature driving, equipment and storage medium. BACKGROUND

[0002] When a pure electric vehicle is used in a low-temperature or extremely cold environment, the working temperature of the battery pack will significantly affect the power output capability and the power release capability of the battery pack. Because the electrochemical properties of a large number of battery cells inside the battery pack will change under low-temperature conditions, the effective discharge capability of the battery cells will decrease, thereby causing the power performance and the endurance level of the vehicle to decrease. Therefore, the vehicle often relies on state parameters such as power information and battery cell temperature information provided by a battery pack management system, and a vehicle controller decides whether the battery pack needs to be heated according to these information. At the same time, a battery pack heater is responsible for heating the coolant to transfer heat to the inside of the battery pack to maintain the battery pack in a suitable working temperature range, thereby ensuring the normal driving performance of the vehicle in a cold environment.

[0003] Under the above technical background, in the traditional technology, when the vehicle is in a low-temperature condition and powered on, the vehicle controller will determine whether the minimum temperature of the battery pack is lower than a low-temperature setting value, and if it is lower than the threshold value, the battery pack heating will be started immediately. The heating process will continue until the minimum temperature of the battery pack rises to a temperature setting value, and then the heating process will stop. In this process, in order to ensure that the battery pack can provide normal power output to the motor in a low-temperature environment, the temperature setting value is usually set to be high, thereby causing the battery pack heater to run for a long time and continuously consume a large amount of energy. When the total discharge capacity of the battery pack is unchanged, the amount of power used by the battery pack to drive the vehicle motor to drive the vehicle is reduced, thereby affecting the low-temperature endurance capability of the vehicle.

[0004] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as prior art. SUMMARY

[0005] The main purpose of the present application is to provide a battery pack heating method and device based on low-temperature driving, equipment and storage medium, which aims to solve the technical problem of how to reduce the excessive consumption of power during the battery pack heating process in a low-temperature driving environment, thereby avoiding the decrease of the endurance capability of the vehicle.

[0006] To achieve the above-mentioned purpose, the present application provides a battery pack heating method based on low-temperature driving, which comprises the following steps: When it is detected that the vehicle is in a low-temperature driving state, the target temperature of the battery pack, the state of charge of the battery pack and a preset state of charge switching threshold value are obtained; determining a target heating control logic according to the state of charge of the battery pack and the preset state of charge switching threshold value; The battery pack is heated according to the target temperature and the target heating control logic, and the battery pack heating based on the low-temperature driving is completed.

[0007] In an embodiment, the step of determining the target heating control logic according to the battery pack state of charge and the preset state of charge switching threshold comprises: When the battery pack state of charge is greater than the preset state of charge switching threshold, the target heating control logic is determined as a first heating control logic; When the battery pack state of charge is less than or equal to the preset state of charge switching threshold, the target heating control logic is determined as a second heating control logic.

[0008] In an embodiment, the step of heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating based on the low-temperature driving comprises: When the target heating control logic is the first heating control logic, a first temperature setting value and a second temperature setting value are determined according to the first heating control logic, wherein the first temperature setting value is less than the second temperature setting value; When the target temperature is less than the first temperature setting value, the battery pack heating is started and a first heating temperature of the battery pack is determined; When the first heating temperature is greater than or equal to the second temperature setting value, the battery pack heating is stopped, and the battery pack heating based on the low-temperature driving is completed.

[0009] In an embodiment, the step of determining the first temperature setting value and the second temperature setting value according to the first heating control logic when the target heating control logic is the first heating control logic comprises: When the target heating control logic is the first heating control logic, the cell self-heating temperature characteristics, the energy consumption decay curve and the typical driving section of the battery pack are obtained; The battery pack heating duration under low temperature and the vehicle range are determined according to the first heating control logic and the energy consumption decay curve; The target temperature interval that can be maintained by self-heating is determined according to the cell self-heating temperature characteristics; The first temperature setting value and the second temperature setting value are determined according to the target temperature interval, the battery pack heating duration and the vehicle range.

[0010] In an embodiment, the step of heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating based on the low-temperature driving comprises: When the target heating control logic is the second heating control logic, a third temperature setpoint and a fourth temperature setpoint are determined according to the second heating control logic, wherein the third temperature setpoint is greater than or equal to the second temperature setpoint and the third temperature setpoint is less than the fourth temperature setpoint. When the target temperature is lower than the third temperature setting value, the battery pack heating is activated and the second heating temperature of the battery pack is determined. When the second heating temperature is greater than or equal to the fourth temperature setting value, the battery pack heating is turned off, thus completing the battery pack heating based on low-temperature driving.

[0011] In one embodiment, the step of determining a third temperature setpoint and a fourth temperature setpoint based on the second heating control logic when the target heating control logic is the second heating control logic includes: When the target heating control logic is the second heating control logic, the allowable discharge power curve, the target power demand of the vehicle in the low battery state, the thermal equilibrium temperature and the heat loss rate are obtained. Based on the allowable discharge power curve, determine the battery pack temperature required to meet the target power demand, and obtain the third temperature setpoint. Determine the target constraints required to meet the target power demand based on the thermal equilibrium temperature. A fourth temperature setpoint is determined based on the target constraints and the heat loss rate.

[0012] In one embodiment, after the step of heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating based on low-temperature driving, the method further includes: When heating is turned on, determine the initial heating state of the battery pack positive temperature coefficient heater; At the end of the heating process, determine the heating termination status of the battery pack positive temperature coefficient heater; The heating time of the battery pack positive temperature coefficient heater is determined based on the initial heating state and the end heating state. The preset state of charge switching threshold is updated based on the heating time to obtain the updated preset state of charge switching threshold.

[0013] In addition, to achieve the above objectives, this application also proposes a battery pack heating device based on low-temperature driving. The battery pack heating device based on low-temperature driving includes: a data acquisition module, used to acquire the target temperature of the battery pack, the state of charge of the battery pack, and a preset state of charge switching threshold when the vehicle is detected to be in a low-temperature driving state. The logic determination module is used to determine the target heating control logic based on the battery pack state of charge and the preset state of charge switching threshold. The battery pack heating module is used to heat the battery pack according to the target temperature and the target heating control logic, thereby completing the battery pack heating based on low-temperature driving.

[0014] In addition, to achieve the above objectives, this application also proposes a battery pack heating device based on low-temperature driving, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the battery pack heating method based on low-temperature driving as described above.

[0015] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the battery pack heating method based on low-temperature driving described above.

[0016] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the battery pack heating method based on low-temperature driving described above.

[0017] One or more technical solutions proposed in this application have at least the following technical effects: By employing a technique that acquires the target battery pack temperature, state of charge (SCC), and preset SCC switching threshold when the vehicle is detected to be in a low-temperature driving state, accurate dual-parameter sensing of both battery temperature and remaining charge status is achieved. Through a technical means of determining the target heating control logic based on the SCC and preset SCC switching threshold, differentiated heating logic based on the remaining battery charge is realized. This technique adapts the heating action to the actual needs of different charge conditions by heating the battery pack according to the target temperature and target heating control logic. Existing technologies, however, rely solely on the single parameter of the battery pack's lowest temperature to trigger and stop heating, without considering the SCC. This results in continued heating at a higher temperature threshold even under high charge conditions, leading to excessively long battery pack heater operating times. Heating consumes a significant amount of power, which in turn reduces the amount of power available from the battery pack for the vehicle's motor drive, thus decreasing the low-temperature range of pure electric vehicles. Furthermore, it fails to guarantee the power output stability of the battery pack under low charge conditions. The aforementioned series of technical measures first address the problems of high heating power consumption and insufficient low-temperature range caused by the single-parameter heating control in existing technologies. Compared to existing technologies, this approach utilizes the synergistic effect of dual-parameter sensing and graded heating logic. Under high charge conditions, it can match an appropriate heating logic to reduce heating time and lower heating power consumption, reserving more power for vehicle drive. This improves the low-temperature driving range of pure electric vehicles. Under low charge conditions, it can switch to the corresponding heating logic to ensure the power output stability of the battery pack and avoid malfunctions such as battery pack power limitation or the instrument panel indicator light illuminating. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of a battery pack heating method for low-temperature driving based on an embodiment of this application. Figure 2 This is a schematic flowchart of Embodiment 2 of the battery pack heating method for low-temperature driving in this application; Figure 3 This is a schematic diagram of the heating test process provided in Embodiment 2 of the battery pack heating method for low-temperature driving in this application; Figure 4 A simplified flowchart illustrating the battery pack heating method for low-temperature driving provided in Embodiment 2 of this application; Figure 5 This is a schematic diagram of the module structure of the battery pack heating device for low-temperature driving according to an embodiment of this application; Figure 6 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the battery pack heating method based on low-temperature driving in the embodiments of this application.

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0023] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0024] The main solution of this application embodiment is: when the vehicle is detected to be in a low-temperature driving state, the target temperature of the battery pack, the state of charge of the battery pack, and the preset state of charge switching threshold are obtained; the target heating control logic is determined according to the state of charge of the battery pack and the preset state of charge switching threshold; the battery pack is heated according to the target temperature and the target heating control logic to complete the battery pack heating based on low-temperature driving.

[0025] In this embodiment, for ease of description, the following description will focus on identifying the battery pack heating device based on low-temperature driving.

[0026] To address the issue of how existing technologies reduce excessive energy consumption during battery pack heating in low-temperature driving environments, thereby preventing a decrease in vehicle range, this application provides a solution. By acquiring the target battery pack temperature, battery pack state of charge (SCC), and a preset SCC switching threshold when the vehicle is detected to be in a low-temperature driving state, this application achieves precise dual-parameter sensing of both battery temperature and remaining charge status. Furthermore, by determining the target heating control logic based on the battery pack SCC and the preset SCC switching threshold, this application enables differentiated grading of the heating logic based on the remaining battery charge. By heating the battery pack according to the target temperature and target heating control logic, the heating action adapts to the actual needs of different charge conditions. In contrast, existing technologies rely solely on the single parameter of the battery pack's lowest temperature to trigger and stop heating, without considering the battery pack SCC, leading to high charge states. The previous technology continued to heat at a relatively high temperature threshold, resulting in excessively long working time and high power consumption of the battery pack heater. This, in turn, diverted the power from the battery pack used for vehicle motor drive, reducing the low-temperature range of pure electric vehicles. Furthermore, it failed to specifically guarantee the power output stability of the battery pack under low charge conditions. The aforementioned series of technical measures first solved the problems of high power consumption and insufficient low-temperature range caused by the single-parameter heating control in existing technologies. Compared with existing technologies, this technology, through the synergistic effect of dual-parameter sensing and graded heating logic, can match and adapt the heating logic under high charge conditions to reduce heating time and power consumption, reserving more power for vehicle drive. This improves the low-temperature driving range of pure electric vehicles. Under low charge conditions, it can switch to the corresponding heating logic to ensure the power output stability of the battery pack and avoid faults such as battery pack power limitation or instrument panel warning lights.

[0027] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device capable of performing the above functions, such as a battery pack heating device for low-temperature driving. The following description uses a battery pack heating device for low-temperature driving as an example to illustrate this embodiment and the subsequent embodiments.

[0028] Based on this, this application provides a battery pack heating method for low-temperature driving, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the battery pack heating method for low-temperature driving according to this application.

[0029] In this embodiment, the battery pack heating method based on low-temperature driving includes steps S10~S30: Step S10: When the vehicle is detected to be in a low-temperature driving state, the target temperature of the battery pack, the state of charge of the battery pack, and the preset state of charge switching threshold are obtained. It should be noted that low-temperature driving conditions refer to the driving conditions of pure electric vehicles in low-temperature or extremely cold environments. Under these conditions, the discharge capacity and power output of the battery pack are easily affected by low temperatures, and the battery pack needs to be heated to ensure its performance.

[0030] Additionally, the target temperature is the lowest temperature of the battery pack, i.e., the lowest temperature of the cells inside the battery pack. This temperature is collected by the battery pack management system and sent to the Controller Area Network (CAN), and is the core temperature basis for determining whether the battery pack needs to be heated.

[0031] Furthermore, the State of Charge (SOC) of the battery pack is the remaining power status of the battery pack. This data is monitored by the Battery Management System (BMS) and sent to the CAN network to reflect the current remaining power status of the battery pack.

[0032] In addition, the preset state of charge switching threshold is a pre-calibrated battery pack SOC threshold, which is the core power threshold that distinguishes the heating control logic of different battery packs. When the battery pack SOC is higher or lower than this threshold, different heating start-stop rules will be triggered.

[0033] Understandably, when the vehicle is detected to be in a low-temperature driving state, the vehicle control unit (VCU) will continuously receive the minimum battery pack temperature signal, which is the target temperature signal, sent by the battery pack management system from the CAN network, as well as the battery pack state of charge signal, and retrieve the pre-calibrated preset state of charge switching threshold to provide data support for determining the heating control logic.

[0034] Step S20: Determine the target heating control logic based on the battery pack state of charge and the preset state of charge switching threshold; It should be noted that the target heating control logic is a battery pack heating start-stop rule determined based on the battery pack state of charge and the preset state of charge switching threshold. It includes control rules corresponding to two sets of temperature thresholds. The two sets of temperature thresholds are the first temperature setpoint and the second temperature setpoint, and the third temperature setpoint and the fourth temperature setpoint, respectively. They satisfy the relationship that the first temperature setpoint is less than the second temperature setpoint and less than or equal to the third temperature setpoint and less than the fourth temperature setpoint.

[0035] Understandably, the obtained state of charge of the battery pack is compared with a preset state of charge switching threshold. If the state of charge of the battery pack is greater than the preset state of charge switching threshold, the corresponding target heating control logic is determined to be a heating start-stop rule based on the first temperature setting value and the second temperature setting value. If the state of charge of the battery pack is equal to or less than the preset state of charge switching threshold, the corresponding target heating control logic is determined to be a heating start-stop rule based on the third temperature setting value and the fourth temperature setting value.

[0036] In one feasible implementation, step S20 may include steps S21-S22: Step S21: When the state of charge of the battery pack is greater than the preset state of charge switching threshold, the target heating control logic is determined to be the first heating control logic. It should be noted that the first heating control logic is a heating start-stop rule corresponding to the battery pack's state of charge being greater than the preset state of charge switching threshold. The corresponding temperature threshold is the first temperature setting value and the second temperature setting value, and the first temperature setting value is less than the second temperature setting value. The core of this logic is that after the battery pack heating is turned on, the heating is turned off when the temperature rises to the second temperature setting value.

[0037] Understandably, the obtained state of charge of the battery pack is compared with a preset state of charge switching threshold. When it is determined that the state of charge of the battery pack is greater than the preset state of charge switching threshold, the target heating control logic at this time is directly determined as the first heating control logic, providing a rule basis for subsequent heating operations to be performed according to this logic.

[0038] Step S22: When the state of charge of the battery pack is less than or equal to the preset state of charge switching threshold, the target heating control logic is determined to be the second heating control logic.

[0039] It should be noted that the second heating control logic is a heating start / stop rule corresponding to the battery pack's state of charge being less than or equal to a preset state of charge switching threshold. The corresponding temperature thresholds are the third temperature setting value and the fourth temperature setting value, and the third temperature setting value is less than the fourth temperature setting value. At the same time, it satisfies the overall size relationship that the first temperature setting value is less than the second temperature setting value and less than or equal to the third temperature setting value and less than the fourth temperature setting value. The core of this logic is to determine whether to start heating based on the comparison result between the battery pack's lowest temperature and the fourth temperature setting value.

[0040] Understandably, the obtained state of charge of the battery pack is compared with a preset state of charge switching threshold. When the state of charge of the battery pack is determined to be less than or equal to the preset state of charge switching threshold, the target heating control logic at this time is determined to be the second heating control logic, providing a rule basis for subsequent heating operations to be performed according to this logic.

[0041] Step S30: Heat the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating based on low-temperature driving.

[0042] It should be noted that battery pack heating is achieved by activating the battery pack heater, also known as the Positive Temperature Coefficient (PTC). The PTC activates the internal heating elements to heat the coolant, which then circulates to the battery pack to exchange heat, thus raising the battery pack temperature. For heat pump models, this is achieved by the vehicle controller sending a CAN signal to the AC unit to enable the battery heating PTC and request the water pump to start. For non-heat pump models, this is achieved by the vehicle controller driving and closing the battery pack heating relay and driving the battery pack water pump to operate.

[0043] Understandably, the heating operation is performed based on the acquired target temperature and the determined target heating control logic. If the battery pack state of charge is greater than the preset state of charge switching threshold and heating has been turned on, the battery pack heating is turned off when the target temperature rises to the second temperature setting value until the battery pack state of charge drops to the preset state of charge switching threshold. If the battery pack state of charge is equal to or less than the preset state of charge switching threshold, the heating does not need to be turned on if the target temperature has risen to the fourth temperature setting value, and the heating is turned on again if the target temperature is less than the fourth temperature setting value, thus completing the battery pack heating based on low-temperature driving.

[0044] In one feasible implementation, step S30 may include steps A31 to A33: Step A31: When the target heating control logic is the first heating control logic, determine the first temperature setpoint and the second temperature setpoint according to the first heating control logic, wherein the first temperature setpoint is less than the second temperature setpoint. It should be noted that the first temperature setpoint is the starting temperature threshold used in the first heating control logic to determine whether to turn on the battery pack heating, and it is a pre-calibrated minimum temperature critical value of the battery pack.

[0045] Furthermore, the second temperature setting value is the termination temperature threshold used in the first heating control logic to determine whether to turn off the battery pack heating, and satisfies the relationship that the first temperature setting value is less than the second temperature setting value, while the second temperature setting value is less than or equal to the third temperature setting value.

[0046] In one feasible implementation, step A31 may include the following steps: When the target heating control logic is the first heating control logic, the cell self-heating temperature characteristics, energy consumption decay curve, and typical driving sections of the battery pack are obtained. The battery pack heating time and vehicle range at low temperatures are determined based on the first heating control logic and the energy consumption decay curve. Based on the self-heating temperature characteristics of the battery cell, the target temperature range that can be maintained by self-heating is determined; The first temperature setting value and the second temperature setting value are determined based on the target temperature range, the battery pack heating time, and the vehicle range.

[0047] It should be noted that the self-heating temperature characteristic of the battery cell refers to the temperature change characteristics of the battery cells inside the battery pack during the discharge process due to the heat generated by internal resistance. In this embodiment, this heat can keep the battery pack temperature basically within a certain range, without the need to turn on the battery pack heater for heating. It is an important reference for determining the battery pack heating temperature threshold.

[0048] Additionally, the energy consumption decay curve is a curve showing the decay law of battery pack capacity under low-temperature conditions as the battery pack heating time and the vehicle driving time change. This curve can reflect the distribution relationship between the power consumption of the battery pack for heating and the power consumption for driving the vehicle. Its data can be obtained by collecting relevant vehicle data through CANape software, i.e., CANape calibration software.

[0049] Furthermore, typical driving sections are road conditions that pure electric vehicles often encounter in low-temperature environments, including different types of road sections such as congested urban roads and smooth suburban roads. The driving power requirements and battery pack discharge status vary in different road sections, which will affect the battery pack heating requirements and the overall vehicle range performance.

[0050] In addition, the battery pack heating time is the working time of the battery pack heater. In the prior art, this time is relatively long due to the high temperature setting value, which will result in more power consumption of the battery pack for heating. In this embodiment, the time needs to be accurately determined in combination with the energy consumption decay curve to reduce heating power consumption.

[0051] Furthermore, the vehicle range is the total distance that the battery pack's charge can support for the vehicle's driving under low-temperature conditions, and its value is negatively correlated with the power consumption of the battery pack heating.

[0052] In addition, the target temperature range is the lowest temperature range of the battery pack that can be maintained by the self-heating of the cells. In this embodiment, when the battery pack temperature is within this range, the self-heating of the cells can ensure the battery pack's discharge capacity and power output, without the need for the battery pack heater to work continuously.

[0053] Understandably, after determining that the target heating control logic is the first heating control logic, the self-heating temperature characteristics of the battery pack cells, the energy consumption decay curve, and typical driving sections are first obtained. Then, combined with the control requirements of the first heating control logic and the energy consumption decay curve, the power consumption of the battery pack heating corresponding to different heating durations at low temperatures is analyzed, thereby determining the appropriate battery pack heating duration and the corresponding vehicle range. Next, based on the self-heating temperature characteristics of the cells, the target temperature range that the cell self-heating can maintain is determined. Finally, by combining the range of the target temperature range, the determined battery pack heating duration, and the vehicle range, the first temperature setpoint and the second temperature setpoint are calibrated, thus completing the accurate determination of the temperature threshold under the first heating control logic.

[0054] Step A32: When the target temperature is lower than the first temperature setting value, turn on the battery pack heating and determine the first heating temperature of the battery pack; It should be noted that the target temperature is the lowest temperature of the battery pack, that is, the lowest temperature of the cells inside the battery pack. This temperature is collected by the battery pack management system and sent to the CAN network, and is the core basis for determining the start and stop of heating.

[0055] Additionally, battery pack heating is achieved by activating the battery pack heater. For heat pump models, this is accomplished by the vehicle controller sending a CAN signal to the AC to enable the battery heating PTC and request the water pump to start. For non-heat pump models, this is accomplished by the VCU driving and controlling the closure of the battery pack heating relay and driving the battery pack water pump to work. The principle is that the heater activates the internal heating components to heat the coolant, and the coolant circulates to the inside of the battery pack to complete heat exchange and raise the temperature of the battery pack.

[0056] Furthermore, the first heating temperature is the lowest cell temperature that changes in real time after the battery pack is heated.

[0057] Understandably, the target temperature is compared with the first temperature setting value. When the target temperature is determined to be lower than the first temperature setting value, the vehicle controller triggers the battery pack heating function. At the same time, it continuously receives the real-time minimum temperature of the battery pack uploaded by the battery pack management system and determines it as the first heating temperature, providing real-time temperature data for the subsequent determination of turning off the heating.

[0058] Step A33: When the first heating temperature is greater than or equal to the second temperature setting value, turn off the battery pack heating to complete the battery pack heating based on low-temperature driving.

[0059] Understandably, the first heating temperature is continuously monitored and compared with the second temperature setpoint. When the first heating temperature is determined to be greater than or equal to the second temperature setpoint, the vehicle controller executes the battery pack heating shutdown operation to complete the battery pack heating under this condition based on low-temperature driving.

[0060] In one feasible implementation, step S30 may include steps B31 to B33: Step B31: When the target heating control logic is the second heating control logic, a third temperature setting value and a fourth temperature setting value are determined according to the second heating control logic, wherein the third temperature setting value is greater than or equal to the second temperature setting value, and the third temperature setting value is less than the fourth temperature setting value. It should be noted that the second heating control logic is the battery pack heating start-stop rule corresponding to the battery pack's state of charge being less than or equal to the preset state of charge switching threshold. The core function of this logic is to ensure the battery pack's discharge capacity and power output in the low-charge state, and to avoid fault phenomena such as battery pack power limitation or the instrument panel's blackout indicator light.

[0061] Additionally, the third temperature setting value is the starting temperature threshold used in the second heating control logic to determine whether to activate battery pack heating. It is a pre-calibrated minimum temperature threshold of the battery pack, and this temperature value is greater than or equal to the second temperature setting value.

[0062] Furthermore, the fourth temperature setting value is the termination temperature threshold used in the second heating control logic to determine whether to turn off the battery pack heating, and it satisfies the relationship that the third temperature setting value is less than the fourth temperature setting value. The calibration of this threshold value needs to take into account the balance between the stability of the battery pack power output and the heating power consumption.

[0063] Understandably, after determining that the target heating control logic is the second heating control logic, the third and fourth temperature setpoints corresponding to this logic will be retrieved from the pre-calibrated parameter system to clarify the critical start and stop temperature standards for battery pack heating under low power conditions, providing a core temperature determination basis for subsequent accurate execution of heating operations.

[0064] Step B32: When the target temperature is less than the third temperature setting value, turn on the battery pack heating and determine the second heating temperature of the battery pack; It should be noted that the target temperature is the lowest temperature of the battery pack, that is, the lowest temperature of the cells inside the battery pack. This temperature is collected by the battery pack management system (BMS) and sent to the CAN network. It is the core data for determining the start and stop of heating under the second heating control logic.

[0065] Furthermore, the second heating temperature is the lowest cell temperature that changes in real time after the battery pack starts heating under the second heating control logic. This temperature is continuously collected by the BMS and uploaded to the CAN network for real-time determination of subsequent heating shutdown operations.

[0066] Understandably, the target temperature is compared with the third temperature setting. When the target temperature is determined to be lower than the third temperature setting, the VCU triggers the battery pack heating function. At the same time, it continuously receives the real-time minimum temperature of the battery pack uploaded by the BMS and determines it as the second heating temperature, providing dynamic temperature data support for the subsequent determination to turn off the heating.

[0067] Step B33: When the second heating temperature is greater than or equal to the fourth temperature setting value, turn off the battery pack heating to complete the battery pack heating based on low-temperature driving.

[0068] Understandably, the second heating temperature is continuously monitored and compared with the fourth temperature setting value. When it is determined that the second heating temperature is greater than or equal to the fourth temperature setting value, the VCU executes the battery pack heating shutdown operation to complete the battery pack heating based on low-temperature driving under low-battery conditions.

[0069] In one feasible implementation, step B31 may include the following steps: When the target heating control logic is the second heating control logic, the allowable discharge power curve, the target power demand of the vehicle in the low battery state, the thermal equilibrium temperature and the heat loss rate are obtained. Based on the allowable discharge power curve, determine the battery pack temperature required to meet the target power demand, and obtain the third temperature setpoint. Determine the target constraints required to meet the target power demand based on the thermal equilibrium temperature. A fourth temperature setpoint is determined based on the target constraints and the heat loss rate.

[0070] It should be noted that the allowable discharge power curve is a curve showing the variation of the maximum discharge power that the battery pack can output at different temperatures. This curve is generated and stored by the BMS in combination with cell performance data. It can intuitively reflect the impact of battery pack temperature on its discharge capacity and is the core reference for determining the temperature setpoint.

[0071] Additionally, the low battery state is when the battery pack's state of charge is less than or equal to a preset state of charge switching threshold. In this state, the battery pack's discharge capacity is easily limited, and precise heating is required to ensure its power output to meet the vehicle's driving needs.

[0072] Furthermore, the target power requirement is the minimum discharge power required to maintain normal operation when the vehicle is in a low-battery and low-temperature driving condition. This power needs to be determined in combination with the actual operating conditions such as the vehicle's motor drive and the power consumption of on-board equipment. It is the core power indicator for determining whether the battery pack temperature meets the standard.

[0073] In addition, the thermal equilibrium temperature is the lowest temperature of the battery cell when the heat generated by the self-heating of the battery cell and the heat dissipated from the battery pack to the outside reach equilibrium in a low-temperature environment. In this embodiment, this temperature can ensure that the battery pack can continuously output the target power without the need for additional continuous heating.

[0074] Furthermore, the heat loss rate is the proportion of heat lost by the battery pack per unit time in a low-temperature driving environment to its total heat. This data is related to the ambient temperature and the insulation performance of the battery pack, and is a key parameter for determining the heating termination temperature.

[0075] In addition, the target constraints are determined based on the thermal equilibrium temperature. They are used to ensure that the battery pack can continuously output the target power requirement when the battery is at a low charge level. The core of these constraints is to keep the battery pack temperature within a range where it can discharge stably.

[0076] Understandably, after determining that the target heating control logic is the second heating control logic, the following steps are taken: first, obtain the allowable discharge power curve of the battery pack, the target power demand under low battery conditions, the battery pack thermal equilibrium temperature, and the heat loss rate under low temperature conditions; then, query the minimum battery pack temperature corresponding to meeting the target power demand through the allowable discharge power curve, and determine this temperature as the third temperature setpoint; next, clarify the target constraint conditions to ensure the stable output of the target power demand of the battery pack based on the thermal equilibrium temperature; finally, combine the target constraint conditions and the heat loss rate to calculate the temperature threshold that can offset heat loss and maintain stable discharge of the battery pack, and determine it as the fourth temperature setpoint, thus completing the accurate calibration of the temperature threshold under the second heating control logic.

[0077] This embodiment provides a battery pack heating method based on low-temperature driving. By intelligently determining the start and stop rules of battery pack heating according to the state of charge of the battery pack and a preset state of charge switching threshold under low-temperature driving conditions of pure electric vehicles, this method solves the technical problem in the prior art where the high power consumption of battery pack heating leads to a reduction in low-temperature driving range. This method achieves the beneficial effects of improving the low-temperature driving range of pure electric vehicles, reducing the power consumption of the battery pack for driving heating, and thereby enhancing users' desire to purchase pure electric vehicles and their market competitiveness.

[0078] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in the first embodiment described above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 2 After step S30, the battery pack heating method based on low-temperature driving further includes steps S40 to S70: Step S40: When heating is turned on, determine the initial heating state of the battery pack positive temperature coefficient heater; It should be noted that the positive temperature coefficient heater of the battery pack is a core component used to provide heating for the battery pack. Its heating power increases with its own temperature. It can achieve heat exchange with the battery pack by heating the coolant and is a key component to ensure the temperature of the battery pack under low temperature conditions.

[0079] Additionally, the initial heating state refers to the state when the battery pack positive temperature coefficient heater is turned on. It includes the specific time point when the heater is turned on, as well as key information such as the operating power and initial temperature of the coolant at the time of turn-on. This serves as the starting reference data for calculating the heating duration.

[0080] Step S50: At the end of heating, determine the heating end status of the battery pack positive temperature coefficient heater; It should be noted that the heating end state is the state when the battery pack positive temperature coefficient heater stops heating. It includes key information such as the moment the heater is turned off, the operating power at the time of shutdown, and the final temperature of the coolant. It is the termination benchmark data for calculating the heating time, and the accuracy of its recording will directly affect the accuracy of the heating time calculation.

[0081] It is understandable that the heating end status of the battery pack positive temperature coefficient heater is recorded at the same time as the battery pack heating function ends, so as to provide a basis for subsequent calculation of heating time.

[0082] Step S60: Determine the heating time of the battery pack positive temperature coefficient heater based on the initial heating state and the end heating state; It should be noted that the heating time is the duration of continuous operation of the battery pack's positive temperature coefficient heater from the moment it is turned on to the moment it is turned off. Its value is calculated from the moment it is turned on in the initial heating state and the moment it is turned off in the final heating state, which can intuitively reflect the power consumption of a single heating cycle.

[0083] It is understandable that the heating time of the battery pack positive temperature coefficient heater can be obtained by calculating the time difference between the start-up time in the initial heating state and the stop-up time in the final heating state.

[0084] Step S70: Update the preset state of charge switching threshold according to the heating time to obtain the updated preset state of charge switching threshold.

[0085] It should be noted that the updated preset state of charge switching threshold is a new critical value obtained by adjusting the original preset state of charge switching threshold in combination with the actual heating time. This allows the threshold to better match the actual driving heating conditions of the vehicle and improve the adaptability of the heating control.

[0086] Understandably, the original preset state of charge switching threshold is adjusted based on the calculated heating time and the energy consumption decay curve to obtain the updated preset state of charge switching threshold.

[0087] Reference Figure 3 , Figure 3 This is a schematic diagram of the heating test process for the first embodiment of the battery pack heating method for low-temperature driving in this application.

[0088] like Figure 3 As shown, starting with a pure electric vehicle, the process begins with device connection and data collection. Next, relevant settings are calibrated, including setting 1 (third temperature setting), setting 2 (fourth temperature setting), setting 3 (first temperature setting), setting 4 (second temperature setting), and setting 5 (preset state of charge switching threshold). After calibration, the vehicle undergoes low-temperature driving conditions, during which the battery pack's minimum temperature, state of charge (SOC), and PTC (Power Toll Collection) activation status are observed. The minimum battery pack temperature is determined by the corresponding SOC setting, and the SOC affects the PTC status; therefore, the PTC activation time is calculated. Finally, the test concludes. The flowchart illustrates how intelligent control technology reduces the PTC heating time, thereby reducing the power consumption for vehicle heating and improving the low-temperature driving range of pure electric vehicles. This embodiment provides a battery pack heating method based on low-temperature driving. By accurately recording the initial and final heating states of the positive temperature coefficient heater of the battery pack under low-temperature driving conditions of a pure electric vehicle, and calculating the heating time accordingly, the method updates the preset state of charge switching threshold. This solves the problem of energy waste caused by insufficient precision in battery pack heating control in the prior art, and achieves the beneficial effects of improving battery pack heating efficiency, reducing unnecessary power consumption, and thus improving the battery pack's low-temperature driving range.

[0089] For example, to help understand the implementation process of the battery pack heating method based on low-temperature driving obtained by combining this embodiment with the above embodiment one, please refer to... Figure 4 , Figure 4 A simplified flowchart of a battery pack heating method for low-temperature driving is provided, specifically: Starting with the battery pack's minimum temperature and State of Charge (SOC), data is transmitted via the vehicle's CAN network. Upon startup, the Vehicle Control Unit (VCU) reads and determines if the battery pack SOC is greater than a preset value of 5, i.e., the preset state of charge switching threshold. If so, the VCU reads and determines if the battery pack's minimum temperature is less than a preset value of 3, i.e., the first temperature setting. If it is, the battery pack heating is activated. Subsequently, the VCU reads and determines if the battery pack's minimum temperature is greater than or equal to a preset value of 4, i.e., the second temperature setting. If it is, the battery pack heating is deactivated. If the battery pack's SOC is not greater than the preset value of 5, the VCU reads and determines if the battery pack's minimum temperature is less than a preset value of 1, i.e., the third temperature setting. If it is, the battery pack heating is activated. Subsequently, the VCU reads and determines if the battery pack's minimum temperature is greater than or equal to a preset value of 2, i.e., the fourth temperature setting. If it is, the battery pack heating is deactivated. The entire process intelligently controls the activation and deactivation of the battery pack heating by judging the battery pack's SOC and temperature, thereby reducing the battery pack's PTC heating operating time and the power consumption for battery pack heating during driving, thus improving the low-temperature driving range of pure electric vehicles.

[0090] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the battery pack heating method based on low-temperature driving. Any simple modifications based on this technical concept are within the protection scope of this application.

[0091] This application also provides a battery pack heating device for low-temperature driving, please refer to... Figure 5 The battery pack heating device based on low-temperature driving includes: The data acquisition module 10 is used to acquire the target temperature of the battery pack, the state of charge of the battery pack, and the preset state of charge switching threshold when the vehicle is detected to be in a low-temperature driving state. Logic determination module 20 is used to determine target heating control logic based on the battery pack state of charge and the preset state of charge switching threshold; The battery pack heating module 30 is used to heat the battery pack according to the target temperature and the target heating control logic, thereby completing the battery pack heating based on low-temperature driving.

[0092] The battery pack heating device for low-temperature driving provided in this application, employing the battery pack heating method for low-temperature driving in the above embodiments, can solve the technical problem of how to reduce excessive power consumption during battery pack heating in low-temperature driving environments, thereby avoiding a decrease in vehicle range. Compared with the prior art, the beneficial effects of the battery pack heating device for low-temperature driving provided in this application are the same as those of the battery pack heating method for low-temperature driving provided in the above embodiments, and other technical features in the battery pack heating device for low-temperature driving are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0093] In one embodiment, the logic determination module 20 is further configured to determine the target heating control logic as the first heating control logic when the state of charge of the battery pack is greater than the preset state of charge switching threshold. When the state of charge of the battery pack is less than or equal to the preset state of charge switching threshold, the target heating control logic is determined to be the second heating control logic.

[0094] In one embodiment, the battery pack heating module 30 is further configured to determine a first temperature setting value and a second temperature setting value according to the first heating control logic when the target heating control logic is the first heating control logic, wherein the first temperature setting value is less than the second temperature setting value. When the target temperature is lower than the first temperature setting value, the battery pack heating is activated and the first heating temperature of the battery pack is determined. When the first heating temperature is greater than or equal to the second temperature setting value, the battery pack heating is turned off, thus completing the battery pack heating based on low-temperature driving.

[0095] In one embodiment, the battery pack heating module 30 is further configured to acquire the cell self-heating temperature characteristics, energy consumption attenuation curve, and typical driving section of the battery pack when the target heating control logic is the first heating control logic. The battery pack heating time and vehicle range at low temperatures are determined based on the first heating control logic and the energy consumption decay curve. Based on the self-heating temperature characteristics of the battery cell, the target temperature range that can be maintained by self-heating is determined; The first temperature setting value and the second temperature setting value are determined based on the target temperature range, the battery pack heating time, and the vehicle range.

[0096] In one embodiment, the battery pack heating module 30 is further configured to determine a third temperature setting value and a fourth temperature setting value according to the second heating control logic when the target heating control logic is the second heating control logic, wherein the third temperature setting value is greater than or equal to the second temperature setting value and the third temperature setting value is less than the fourth temperature setting value; When the target temperature is lower than the third temperature setting value, the battery pack heating is activated and the second heating temperature of the battery pack is determined. When the second heating temperature is greater than or equal to the fourth temperature setting value, the battery pack heating is turned off, thus completing the battery pack heating based on low-temperature driving.

[0097] In one embodiment, the battery pack heating module 30 is further configured to acquire the allowable discharge power curve, the target power demand of the vehicle in a low battery state, the thermal equilibrium temperature, and the heat loss rate when the target heating control logic is the second heating control logic. Based on the allowable discharge power curve, determine the battery pack temperature required to meet the target power demand, and obtain the third temperature setpoint. Determine the target constraints required to meet the target power demand based on the thermal equilibrium temperature. A fourth temperature setpoint is determined based on the target constraints and the heat loss rate.

[0098] In one embodiment, the battery pack heating module 30 is further configured to determine the initial heating state of the battery pack positive temperature coefficient heater when heating is turned on; At the end of the heating process, determine the heating termination status of the battery pack positive temperature coefficient heater; The heating time of the battery pack positive temperature coefficient heater is determined based on the initial heating state and the end heating state. The preset state of charge switching threshold is updated based on the heating time to obtain the updated preset state of charge switching threshold.

[0099] This application provides a battery pack heating device for low-temperature vehicles. The battery pack heating device for low-temperature vehicles includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the battery pack heating method for low-temperature vehicles in the above embodiment 1.

[0100] The following is for reference. Figure 6 This document illustrates a structural schematic diagram of a battery pack heating device suitable for implementing embodiments of this application based on low-temperature driving. The battery pack heating device for low-temperature driving in this application embodiment may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), and in-vehicle terminals (e.g., in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers. Figure 6 The battery pack heating device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of this application.

[0101] likeFigure 6 As shown, the battery pack heating device for cryogenic vehicles may include a processing unit 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in ROM (Read Only Memory) 1002 or a program loaded from storage device 1003 into RAM (Random Access Memory) 1004. RAM 1004 also stores various programs and data required for the operation of the battery pack heating device for cryogenic vehicles. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. Input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the battery pack heating device for cryogenic vehicles to communicate wirelessly or wiredly with other devices to exchange data. Although a battery pack heating device for cryogenic vehicles with various systems is shown in the figure, it should be understood that it is not required to implement or possess all the systems shown. More or fewer systems can be implemented alternatively.

[0102] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0103] The battery pack heating device for low-temperature driving provided in this application, employing the battery pack heating method for low-temperature driving in the above embodiments, can solve the technical problem of how to reduce excessive power consumption during battery pack heating in low-temperature driving environments, thereby avoiding a decrease in vehicle range. Compared with the prior art, the beneficial effects of the battery pack heating device for low-temperature driving provided in this application are the same as those of the battery pack heating method for low-temperature driving provided in the above embodiments, and other technical features in this battery pack heating device for low-temperature driving are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0104] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0105] 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.

[0106] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the battery pack heating method based on low-temperature driving in the above embodiments.

[0107] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), Erasable Programmable Read Only Memory (EPROM), optical fiber, CD-ROM (CD-Read Only Memory), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0108] The aforementioned computer-readable storage medium may be included in the battery pack heating device for cryogenic vehicles; or it may exist independently and not assembled into the battery pack heating device for cryogenic vehicles.

[0109] The aforementioned computer-readable storage medium carries one or more programs that, when executed by a battery pack heating device for low-temperature driving, cause the battery pack heating device for low-temperature driving to: when detecting that the vehicle is in a low-temperature driving state, acquire the target temperature of the battery pack, the state of charge of the battery pack, and a preset state of charge switching threshold; determine target heating control logic based on the state of charge of the battery pack and the preset state of charge switching threshold; and perform battery pack heating based on the target temperature and the target heating control logic to complete the battery pack heating for low-temperature driving.

[0110] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including LAN (Local Area Network) or WAN (Wide Area Network)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0111] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0112] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0113] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described battery pack heating method based on low-temperature driving. This solves the technical problem of reducing excessive power consumption during battery pack heating in low-temperature driving environments, thereby preventing a decrease in vehicle range. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the battery pack heating method based on low-temperature driving provided in the above embodiments, and will not be repeated here.

[0114] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the battery pack heating method for low-temperature driving described above.

[0115] The computer program product provided in this application can solve the technical problem of reducing excessive power consumption during battery pack heating in low-temperature driving environments, thereby avoiding a decrease in vehicle range. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the battery pack heating method based on low-temperature driving provided in the above embodiments, and will not be repeated here.

[0116] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for heating a battery pack during low-temperature driving, characterized in that, The method includes: When the vehicle is detected to be in a low-temperature driving state, the target temperature of the battery pack, the state of charge of the battery pack, and the preset state of charge switching threshold are obtained. The target heating control logic is determined based on the battery pack state of charge and the preset state of charge switching threshold. The battery pack is heated according to the target temperature and the target heating control logic to complete the battery pack heating based on low-temperature driving.

2. The method as described in claim 1, characterized in that, The step of determining the target heating control logic based on the battery pack state of charge and the preset state of charge switching threshold includes: When the state of charge of the battery pack is greater than the preset state of charge switching threshold, the target heating control logic is determined to be the first heating control logic; When the state of charge of the battery pack is less than or equal to the preset state of charge switching threshold, the target heating control logic is determined to be the second heating control logic.

3. The method as described in claim 1, characterized in that, The step of heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating for low-temperature driving includes: When the target heating control logic is the first heating control logic, a first temperature setpoint and a second temperature setpoint are determined according to the first heating control logic, wherein the first temperature setpoint is less than the second temperature setpoint. When the target temperature is lower than the first temperature setting value, the battery pack heating is activated and the first heating temperature of the battery pack is determined. When the first heating temperature is greater than or equal to the second temperature setting value, the battery pack heating is turned off, thus completing the battery pack heating based on low-temperature driving.

4. The method as described in claim 3, characterized in that, When the target heating control logic is the first heating control logic, the step of determining the first temperature setpoint and the second temperature setpoint according to the first heating control logic includes: When the target heating control logic is the first heating control logic, the cell self-heating temperature characteristics, energy consumption decay curve and typical driving section of the battery pack are obtained; The battery pack heating time and vehicle range at low temperatures are determined based on the first heating control logic and the energy consumption decay curve. Based on the self-heating temperature characteristics of the battery cell, the target temperature range that can be maintained by self-heating is determined; The first temperature setting value and the second temperature setting value are determined based on the target temperature range, the battery pack heating time, and the vehicle range.

5. The method as described in claim 1, characterized in that, The step of heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating for low-temperature driving includes: When the target heating control logic is the second heating control logic, a third temperature setpoint and a fourth temperature setpoint are determined according to the second heating control logic, wherein the third temperature setpoint is greater than or equal to the second temperature setpoint and the third temperature setpoint is less than the fourth temperature setpoint. When the target temperature is lower than the third temperature setting value, the battery pack heating is activated and the second heating temperature of the battery pack is determined. When the second heating temperature is greater than or equal to the fourth temperature setting value, the battery pack heating is turned off, thus completing the battery pack heating based on low-temperature driving.

6. The method as described in claim 5, characterized in that, When the target heating control logic is the second heating control logic, the step of determining the third temperature setpoint and the fourth temperature setpoint according to the second heating control logic includes: When the target heating control logic is the second heating control logic, the allowable discharge power curve, the target power demand of the vehicle in the low battery state, the thermal equilibrium temperature and the heat loss rate are obtained. Based on the allowable discharge power curve, determine the battery pack temperature required to meet the target power demand, and obtain the third temperature setpoint. Determine the target constraints required to meet the target power demand based on the thermal equilibrium temperature. A fourth temperature setpoint is determined based on the target constraints and the heat loss rate.

7. The method as described in claim 1, characterized in that, After the step of heating the battery pack according to the target temperature and the target heating control logic to complete the battery pack heating based on low-temperature driving, the method further includes: When heating is turned on, determine the initial heating state of the battery pack positive temperature coefficient heater; At the end of the heating process, determine the heating termination status of the battery pack positive temperature coefficient heater; The heating time of the battery pack positive temperature coefficient heater is determined based on the initial heating state and the end heating state. The preset state of charge switching threshold is updated based on the heating time to obtain the updated preset state of charge switching threshold.

8. A battery pack heating device for low-temperature driving, characterized in that, The device includes: The data acquisition module is used to acquire the target temperature of the battery pack, the state of charge of the battery pack, and the preset state of charge switching threshold when the vehicle is detected to be in a low-temperature driving state. The logic determination module is used to determine the target heating control logic based on the battery pack state of charge and the preset state of charge switching threshold. The battery pack heating module is used to heat the battery pack according to the target temperature and the target heating control logic, thereby completing the battery pack heating based on low-temperature driving.

9. A battery pack heating device for low-temperature driving, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the battery pack heating method for low-temperature driving as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the battery pack heating method based on low-temperature driving as described in any one of claims 1 to 7.

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