Heating control method and device for vehicle battery

Abstract

The invention relates to a heating control method and apparatus for a vehicle battery. The method comprises the steps that the environment temperature and the battery output power of the vehicle are obtained; whether the environment temperature is smaller than a preset environment temperature threshold value or not is determined; when it is determined that the environment temperature is smaller than the preset environment temperature threshold value, whether battery heating setting is started or not is determined; and when it is determined that the battery heating setting is started, the vehicle battery is controlled to be heated so that the battery output power can be between the first reference power and the second reference power. The present invention maintains a battery output power within a range determined by a first reference power (i.e., a heating-on threshold) and a second reference power (i.e., a heating-off threshold) to reduce fluctuations in the battery output power, thereby improving a driving experience.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle batteries, and in particular to a heating control method and device for a vehicle battery. Background Art

[0002] As the power source of electric vehicles, it is crucial to ensure that the battery works efficiently. Among the many influencing factors, battery temperature has the greatest impact on the battery's charge and discharge performance. Usually, within a certain temperature range, the battery's discharge current will decrease as the temperature decreases, and the battery's output power will also decrease as the temperature drops. Therefore, in order to ensure the battery's efficient working state and avoid the battery being in a state of low performance for a long time, it is necessary to add a heating function to the battery. Good heating performance is conducive to extending battery life, improving vehicle safety levels, reducing vehicle energy consumption, and increasing driving range.

[0003] At present, the battery heating control method is usually: triggering the battery heating according to the battery temperature and the state of charge (SOC), that is, when the battery SOC is less than a preset SOC threshold (for example, 30%), when the battery temperature is less than a preset temperature threshold (for example, -5°C), the vehicle controls to turn on the battery heating function, and when the battery temperature is greater than another preset temperature threshold (for example, 15°C), the vehicle controls to turn off the battery heating function. The battery heating function is achieved by heating the positive temperature coefficient (PTC) element of the air conditioner.

[0004] However, the main problems with such a battery heating control method are: the battery heating function will not be turned on when the SOC is high and the temperature is low (for example, the SOC is 50% and the battery temperature is -20°C). Since the output power of batteries at different temperatures varies greatly, determining whether the battery is heated based on the battery temperature will cause the battery output power to fluctuate, resulting in a poor driving experience. When the vehicle is driving slowly, the power required for the vehicle to drive is very low, and heating the battery at this time will waste the battery's energy. On the contrary, when the vehicle is driving rapidly, the battery output power may not be able to meet the higher power required for the vehicle to drive.

[0005] In addition, vehicles have different driving modes, such as normal mode, economy mode, sports mode, etc. However, the conventional battery heating control method also maintains the same heating triggering conditions in different driving modes. Therefore, the same battery maximum discharge power map is generated in different driving modes, resulting in a vague driving experience.

[0006] The above description of the background technology is only for facilitating an in-depth understanding of the technical solution of the present invention (such as the technical means used, the technical problems solved and the technical effects produced), and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0007] The object of the present invention is to provide a heating control method and device for a vehicle battery, which can reduce the fluctuation of the battery output power and thus improve the driving experience.

[0008] According to an embodiment of the present invention, a heating control method for a vehicle battery is provided, and the method may include the following steps: obtaining the ambient temperature and battery output power of the vehicle through a receiver; determining through a controller whether the ambient temperature is less than a preset ambient temperature threshold; when it is determined that the ambient temperature is less than the preset ambient temperature threshold, determining through the controller whether a battery heating setting is turned on; and when it is determined that the battery heating setting is turned on, controlling the vehicle battery heating through the controller so that the battery output power is between a first reference power and a second reference power.

[0009] The method may further include the following steps: obtaining a reference temperature, a battery temperature and a battery SOC of the vehicle through a receiver; determining a maximum battery discharge power according to the reference temperature and the battery SOC through a controller; obtaining a driving mode of the vehicle and a preset power corresponding to the driving mode through a receiver; determining through a controller whether the maximum battery discharge power is greater than the preset power corresponding to the driving mode; when the maximum battery discharge power is greater than the preset power corresponding to the driving mode, calculating a first reference power and a second reference power through a controller, and controlling the vehicle battery heating through the controller so that the battery output power is between the first reference power and the second reference power.

[0010] Controlling the vehicle battery heating so that the battery output power is between the first reference power and the second reference power may include the following steps: determining by a controller whether the battery output power is less than the first reference power; when it is determined that the battery output power is less than the first reference power, heating the battery by the controller. In the process of heating the battery, determining by the controller whether the battery temperature is greater than or equal to a preset battery temperature threshold; when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold, stopping the battery heating by the controller; when it is determined that the battery temperature is less than the preset battery temperature threshold, determining by the controller whether the battery output power is greater than or equal to the second reference power, and when it is determined that the battery output power is greater than or equal to the second reference power, stopping the battery heating by the controller.

[0011] The first reference power and the second reference power can be calculated according to the following formulas: first reference power = (power of the motor + power of the air conditioner + power of the low-voltage electrical appliance) × first factor; second reference power = (power of the motor + power of the air conditioner + power of the low-voltage electrical appliance) × second factor; wherein the power of the motor is a preset power corresponding to the driving mode of the vehicle.

[0012] The driving modes of the vehicle may include a normal mode, an economic mode, and a sports mode. The first factor may be 1.1, and the second factor may be 1.2.

[0013] The method may further include the following steps: heating the battery by a controller when the maximum discharge power of the battery is less than a preset power corresponding to the driving mode; and using the maximum discharge power of the battery as a second reference power by the controller to control the heating of the vehicle battery so that the battery output power is within the second reference power.

[0014] Controlling vehicle battery heating so that the battery output power is within a second reference power may include the following steps: during the battery heating process, determining through a controller whether the battery temperature is greater than or equal to a preset battery temperature threshold; when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold, stopping the battery heating through the controller; when it is determined that the battery temperature is less than the preset battery temperature threshold, determining through the controller whether the battery output power is greater than or equal to the second reference power, and when it is determined that the battery output power is greater than or equal to the second reference power, stopping the battery heating through the controller.

[0015] The method may further include the following steps: when it is determined that the ambient temperature is greater than or equal to a preset ambient temperature threshold, the battery heating is not performed by the controller; and when it is determined that the ambient temperature is less than the preset ambient temperature threshold, when it is determined that the battery heating setting is turned off, the battery heating is not performed by the controller.

[0016] The battery output power may be a maximum value of the battery output power within a reference time period.

[0017] The method may further include the following steps: after stopping heating the battery, determining by a controller whether the battery output power is less than a second reference power; when the battery output power is less than the second reference power, calculating by the controller the difference in average battery output power in adjacent preset time periods; and increasing or decreasing the battery insulation heating power based on the difference by the controller.

[0018] The method may further include the following steps: when the difference between the average battery output power in a preset time period and the average battery output power in a next preset time period is greater than zero, the battery insulation and heating power is increased by the difference through the controller; and when the difference between the average battery output power in a preset time period and the average battery output power in the next preset time period is less than or equal to zero, the battery insulation and heating power is reduced by the difference through the controller.

[0019] The method may further include the following steps: during the process of heating the battery, determining whether the battery temperature is greater than or equal to a preset battery temperature threshold, and stopping the battery heating when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold.

[0020] According to another embodiment of the present invention, a heating control device for a vehicle battery is provided, and the device may include a receiver and a controller. The receiver may be configured to: obtain the ambient temperature of the vehicle and the battery output power. The controller may be configured to: determine whether the ambient temperature is less than a preset ambient temperature threshold; when it is determined that the ambient temperature is less than the preset ambient temperature threshold, determine whether the battery heating setting is turned on; when it is determined that the battery heating setting is turned on, control the vehicle battery heating so that the battery output power is between a first reference power and a second reference power.

[0021] The receiver may be further configured to: obtain a reference temperature, a battery temperature of the vehicle, and a battery SOC; obtain a driving mode of the vehicle and a preset power corresponding to the driving mode. The controller may be further configured to: determine a maximum battery discharge power according to the reference temperature and the battery SOC; determine whether the maximum battery discharge power is greater than the preset power corresponding to the driving mode; when the maximum battery discharge power is greater than the preset power corresponding to the driving mode, calculate a first reference power and a second reference power, and control the vehicle battery heating so that the battery output power is between the first reference power and the second reference power.

[0022] When controlling the vehicle battery heating so that the battery output power is between a first reference power and a second reference power, the controller can be configured to: determine whether the battery output power is less than the first reference power; when it is determined that the battery output power is less than the first reference power, heat the battery; during the battery heating process, determine whether the battery temperature is greater than or equal to a preset battery temperature threshold; when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold, stop the battery heating; when it is determined that the battery temperature is less than the preset battery temperature threshold, determine whether the battery output power is greater than or equal to the second reference power; when it is determined that the battery output power is greater than or equal to the second reference power, stop the battery heating.

[0023] The controller can be configured to calculate the first reference power and the second reference power according to the following formula: first reference power = (power of the motor + power of the air conditioner + power of the low-voltage electrical appliance) × first factor; second reference power = (power of the motor + power of the air conditioner + power of the low-voltage electrical appliance) × second factor; wherein the power of the motor is a preset power corresponding to the driving mode of the vehicle.

[0024] The driving modes of the vehicle may include a normal mode, an economic mode, and a sports mode. The first factor may be 1.1, and the second factor may be 1.2.

[0025] The controller can be configured to heat the battery when the maximum discharge power of the battery is less than a preset power corresponding to the driving mode, and use the maximum discharge power of the battery as a second reference power to control the heating of the vehicle battery so that the battery output power is within the second reference power.

[0026] When controlling the vehicle battery heating so that the battery output power is within a second reference power, the controller can be configured to: determine whether the battery temperature is greater than or equal to a preset battery temperature threshold, and when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold, stop the battery heating; when it is determined that the battery temperature is less than the preset battery temperature threshold, determine whether the battery output power is greater than or equal to the second reference power, and when it is determined that the battery output power is greater than or equal to the second reference power, stop the battery heating.

[0027] The controller may be configured to: not perform battery heating when it is determined that the ambient temperature is greater than or equal to a preset ambient temperature threshold; and not perform battery heating when it is determined that the battery heating setting is turned off and the ambient temperature is less than the preset ambient temperature threshold.

[0028] The battery output power may be a maximum value of the battery output power within a reference time period.

[0029] The controller can be further configured to: after stopping heating the battery, determine whether the battery output power is less than a second reference power; and when the battery output power is less than the second reference power, calculate the difference in average battery output power in adjacent preset time periods, and increase or decrease the battery insulation heating power based on the difference.

[0030] The controller can be configured as follows: when the difference between the average battery output power in a preset time period and the average battery output power in a next preset time period is greater than zero, the battery insulation and heating power is increased by the difference; when the difference between the average battery output power in a preset time period and the average battery output power in the next preset time period is less than or equal to zero, the battery insulation and heating power is reduced by the difference.

[0031] The controller may be further configured to: during the process of heating the battery, determine whether the battery temperature is greater than or equal to a preset battery temperature threshold, and stop the battery heating when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold.

[0032] The present invention adopts the above technical solution, which has the following beneficial effects:

[0033] The battery heating condition is determined according to the vehicle's external ambient temperature, battery temperature, battery SOC, battery maximum discharge power, and battery output power, so that the battery output power is maintained within the range determined by the first reference power (i.e., heating on threshold) and the second reference power (i.e., heating off threshold). Therefore, the fluctuation of the battery output power can be reduced and the driving experience can be improved;

[0034] The first reference power and the second reference power are set by using different output value targets according to the battery SOC, so as to adapt to the influence of the state change of the battery SOC on the battery performance; when the SOC of the vehicle is in a high state, the calculation result of the preset power is used as the output value target for heating, and when the SOC of the vehicle is in a low state, the battery maximum discharge power curve is used as the output value target for heating.

[0035] Different preset powers are set for the heating on threshold and heating off threshold for different driving modes (normal mode, economy mode or sports mode). In sports mode, the battery output power can be kept as consistent as possible with the battery output power at normal temperature. In normal mode, the All Electric Range (AER) value can be extended. In economy mode, the vehicle can travel farther in winter. Different battery output power curves can be obtained in different driving modes, so that the driver's driving experience in different driving modes can be distinguished, that is, the driver can clearly feel the different torque output in winter;

[0036] After stopping heating the battery, in order to slow down the decline in battery output power, enabling the "temperature maintenance" function can further reduce the fluctuation of battery output power, thereby avoiding repeated heating processes and avoiding vehicle torque fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The following will describe the exemplary embodiments of the present invention in more detail with reference to the accompanying drawings. For the sake of clarity, the same components in different drawings are shown with the same reference numerals. It should be noted that the drawings are only for illustration and are not necessarily drawn to scale. In these drawings:

[0038] Figures 1A to 1CIt is a curve diagram of battery output power, battery temperature and battery SOC when the battery is heated using a traditional battery heating control method under different vehicle driving power requirements.

[0039] Figure 2 is a flowchart of a heating control method of a vehicle battery according to an embodiment of the present invention.

[0040] Figure 3 It is a curve diagram of the first reference power, the second reference power and the battery output power, the battery temperature, the battery SOC and the power required for vehicle driving in the sport mode, the normal mode and the economy mode using the heating control method of the vehicle battery according to the embodiment of the present invention.

[0041] Figure 4 1 is a schematic diagram showing heating of a battery according to different target powers for heating in a heating control method of a vehicle battery according to an embodiment of the present invention.

[0042] Figure 5 is a graph of battery output power, battery SOC, battery temperature, and battery heating power in the case of using a heating control method of a vehicle battery according to an embodiment of the present invention.

[0043] Figure 6 is a flowchart of a heating control method of a vehicle battery when the battery is reheated according to an embodiment of the present invention.

[0044] Figure 7 is a block diagram of a heating control device of a vehicle battery according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The implementation scheme of the present invention is described in detail below. This implementation scheme is implemented on the premise of the technical scheme of the present invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the implementation scheme described below.

[0046] Figures 1A to 1C This is a graph of battery output power, battery temperature, and battery state of charge (SOC) when the battery is heated using a traditional battery heating control method under different vehicle driving power requirements. Figures 1A to 1CDuring the driving of the vehicle, the battery SOC tends to decrease. In the traditional battery heating control method, when the battery temperature is less than a preset temperature threshold (for example, -5°C), the vehicle controls the battery heating function to be turned on. Therefore, the battery temperature can be kept stable within a certain range, and the battery output power depends on the battery SOC and battery temperature. When the battery SOC decreases and the battery temperature remains stable, the battery output power fluctuates. In particular, in this case, the battery output power is generally in a declining state, resulting in a poor driving experience.

[0047] Figure 1A The curve of the power required for the vehicle to travel and the curve of the battery output power when the vehicle is traveling slowly are shown. Figure 1A As shown, the curve of battery output power is above the curve of power required for vehicle driving. When the vehicle is driving slowly, the power required for vehicle driving is low, but the battery output power in the battery heating state is much higher than the power required for vehicle driving, which may cause excessive heating of the battery and waste of energy. Figure 1C The graph shows the power required for the vehicle to travel when the vehicle is traveling rapidly and the battery output power. Figure 1C In the area ③ shown, the curve of the battery output power is below the curve of the power required for vehicle driving. When the vehicle is driving rapidly, the power required for vehicle driving is high, but the battery output power in the heated state is much lower than the power required for vehicle driving, resulting in insufficient heating of the battery and the battery output power cannot meet the driving needs of the vehicle. Figure 1B The graph shows the power required by the vehicle and the battery output power when the vehicle is traveling in an intermediate state between slow driving and fast driving. Figure 1B In the area ① shown, the curve of the battery output power is above the curve of the power required for vehicle driving. In this case, the battery heats up too quickly, causing the battery output power to be too high, resulting in energy waste. Figure 1B In the area ② shown, the curve of the power required for vehicle driving is above the curve of the battery output power. In this case, the heating temperature is too low, which makes the battery output power too low, resulting in the battery output power being unable to meet the vehicle's driving needs.

[0048] Figure 2 : is a flow chart of a heating control method of a vehicle battery according to an embodiment of the present invention. Figure 2As shown, the vehicle battery heating control method according to the embodiment of the present invention may include: obtaining the ambient temperature of the vehicle and the battery output power (S11). In a specific embodiment, the ambient temperature of the vehicle may be obtained from a dual automatic temperature control (DATC) system, and the battery output power may be obtained from a vehicle-mounted battery management system (BMS).

[0049] The vehicle battery heating control method according to the embodiment of the present invention determines whether the ambient temperature is less than a preset ambient temperature threshold (S12). Those skilled in the art can set the preset ambient temperature threshold according to the temperature characteristics of winter.

[0050] When it is determined that the ambient temperature is greater than or equal to the preset ambient temperature threshold (“No” in S12 ), the battery heating is not performed ( S24 ).

[0051] When it is determined that the ambient temperature is less than the preset ambient temperature threshold ("Yes" of S12), it is determined whether the battery heating setting is turned on (S13). When it is determined that the battery heating setting is turned off ("No" of S13), the battery heating is not performed (S24). Specifically, the option of the battery heating setting can be provided by the vehicle's audio, video, navigation and telematics (Audio Video Navigation Telematics, AVNT) system. The user can select the option of the battery heating setting by pressing a button or touching the option displayed on the display. For example, when the user does not select the option of the battery heating setting, the battery heating setting is turned off. When the user selects the option of the battery heating setting, the battery heating setting is turned on.

[0052] In order to solve the problems caused by the conventional vehicle battery heating control method, the vehicle battery heating control method according to the embodiment of the present invention maintains the battery output power within a specific range to reduce the fluctuation of the battery output power and improve the driving experience. The specific range can be determined by the first reference power and the second reference power, the first reference power is used as the heating on threshold, and the second reference power is used as the heating off threshold. Therefore, when it is determined that the battery heating is set to on ("Yes" of S13), the vehicle battery heating control method according to the embodiment of the present invention also includes the following steps: determining whether the battery output power is less than the first reference power (S19). When the battery output power is less than the first reference power ("Yes" of S19), the battery is heated (S20). As the battery is heated, the battery output power rises. If the battery output power is greater than or equal to the second reference power greater than the first reference power ("Yes" of S21), the battery heating is stopped (S23).

[0053] In a specific embodiment, the battery output power may be the maximum value of the battery output power within a reference time period. Figures 1A to 1C Taking the battery output power curve in FIG. 1 as an example, the maximum value of the battery output power curve in the reference time period can be used as the battery output power. The reference time period can be 10s or 30s, but is not limited thereto.

[0054] The first reference power and the second reference power can be determined based on the target power required by the current load of the battery. The target power here refers to the power value required for a specific operating condition of the vehicle, which can be obtained by vehicle calibration testing in order to obtain the best power and energy-saving effect. When the electric vehicle is in operation, the load of the battery is mainly the motor, or it can also be other electronic equipment in the car (for example, air conditioners and low-voltage electrical appliances). The battery output power needs to meet the normal operation requirements of the above-mentioned loads in the vehicle. Therefore, the first reference power and the second reference power are set with reference to the target power required by the current load of the battery, which not only meets the normal power requirements of the load, but also sets the start and end time of heating properly, reducing energy consumption.

[0055] In a specific implementation, the first reference power and the second reference power may be determined according to the following formula:

[0056] The first reference power = (motor power + air conditioner power + low voltage electrical appliance power) × the first factor

[0057] Second reference power = (motor power + air conditioner power + low voltage electrical appliance power) × second factor

[0058] Among them, the power of the motor can be pre-set to different power values ​​according to the driving mode of the vehicle. The power of the air conditioner can be the power value of the positive temperature coefficient (PTC) element of the air conditioner. The power of the low-voltage electrical appliance can include the power values ​​of the headlights, blowers, fans, etc. The second factor is greater than the first factor. The first factor and the second factor can be determined based on multiple tests in the vehicle development stage. In a specific example, the first factor can be 1.1 and the second factor can be 1.2. In addition, depending on the vehicle, the values ​​of the calibrated first factor and second factor may be different. The driving mode of the vehicle may include a sports mode, a normal mode, and an economic mode (ECO). The heating control method of the vehicle battery according to an embodiment of the present invention may also include: obtaining the driving mode of the vehicle and the preset power corresponding to the driving mode (S16). In a specific embodiment, the driving mode of the vehicle can be obtained by obtaining the state of the selection switch of the driving mode.

[0059] Different driving modes have different specific characteristics. The sports mode focuses on power. In the sports mode, the dynamic performance of the vehicle can be given priority, while the energy consumption of battery heating is ignored. Therefore, the preset power corresponding to the sports mode is higher. The normal mode is a mode that combines power and economy. The normal mode needs to have good power and relatively good economy. Therefore, the preset power corresponding to the normal mode is relatively neither high nor low. The economic mode mainly highlights economy and can improve the energy utilization rate of the vehicle. In the economic mode, it is preferred to consider reducing the energy used for battery heating and extending the vehicle's all-electric driving range (All Electric Range, AER). Therefore, the preset power corresponding to the economic mode is lower. The preset power corresponding to the vehicle's driving mode can be determined based on multiple tests during the vehicle development stage. In a specific implementation scheme, the preset power of the sports mode can be set to 120kw, the preset power of the normal mode can be set to 100kw, and the preset power of the economic mode can be set to 60kw.

[0060] Figure 3 1 is a graph of the first reference power, the second reference power and the battery output power, the battery temperature, the battery SOC and the power required for vehicle running in the sport mode, the normal mode and the economy mode using the battery heating control method according to the embodiment of the present invention.

[0061] like Figure 3 As shown, during the running of the vehicle, the battery SOC tends to decrease. In the case of using the vehicle battery heating control method according to the embodiment of the present invention, after the vehicle control turns on the battery heating function, the battery temperature tends to increase.

[0062] Since the preset power in the sports mode is greater than the preset power in the normal mode, and the preset power in the normal mode is greater than the preset power in the economic mode, therefore, after calculation of the above-mentioned first reference power and second reference power formulas, the first reference power in the sports mode is greater than the first reference power in the normal mode, the first reference power in the normal mode is greater than the first reference power in the economic mode, the second reference power in the sports mode is greater than the second reference power in the normal mode, and the second reference power in the normal mode is greater than the second reference power in the economic mode. Figure 3 In the figure, multiple straight lines indicate from top to bottom the second reference power in sports mode, the first reference power in sports mode, the second reference power in normal mode, the first reference power in normal mode, the second reference power in economy mode, and the first reference power in economy mode.

[0063] Since the battery heating is performed when the battery output power is less than the first reference power, the battery heating stops when the battery output power is greater than or equal to the second reference power, and the battery output power is the maximum value of the battery output power curve within a predetermined time period, therefore, during the battery heating process, the battery output power curve in the sports mode is substantially located between the straight line indicating the first reference power in the sports mode and the straight line indicating the second reference power in the sports mode, and the maximum value of the battery output power curve in the sports mode does not exceed the straight line indicating the second reference power in the sports mode. Similarly, the battery output power curves in the normal mode and the economy mode are substantially located between the straight line indicating the first reference power in the corresponding mode and the straight line indicating the second reference power in the corresponding mode, and the maximum value of the battery output power curves in the normal mode and the economy mode does not exceed the straight line indicating the second reference power in the corresponding mode. The heating control method of the vehicle battery according to the embodiment of the present invention can reduce the fluctuation of the battery output power and improve the driving experience.

[0064] In sports mode, the battery output power curve is above the power curve required for vehicle driving. The vehicle can have a high battery output power, keeping the battery output power as consistent as possible with the battery output power at normal temperature.

[0065] In normal mode, the battery output power curve is above the power curve required for vehicle travel, but the distance between the battery output power curve and the power curve required for vehicle travel is not far. The battery output power is greater than the power required for vehicle travel to meet the vehicle's travel needs, and the difference between the battery output power and the power required for vehicle travel is not too large to avoid wasting battery energy. According to an embodiment of the present invention, on the premise of meeting the user's basic driving needs, the battery can be controlled to start heating at the best time, which can avoid the battery heating function from being turned on in advance. In addition, it also avoids the battery heating function from not being turned on when the vehicle's power does not meet the user's basic driving needs (i.e., the battery heating function is delayed). While improving the vehicle's power performance, it also reduces the extra consumption of battery energy.

[0066] In economy mode, the battery output power curve is below the power curve required for vehicle driving. The vehicle can reduce the battery energy used for battery heating and extend the vehicle's AER.

[0067] According to the embodiment of the present invention, different reference powers are set for different driving modes (normal mode, economic mode or sports mode), and different battery output power curves can be obtained. Therefore, the driving experience of the driver in different driving modes can be differentiated, that is, the driver can clearly feel different torque outputs in different driving modes.

[0068] However, when the SOC of the vehicle is in a low state, using the calculation result of the preset power as the target power for heating will cause overheating of the battery, resulting in energy waste. Therefore, according to an embodiment of the present invention, when the SOC of the vehicle is in a low state, the maximum discharge power curve of the battery at the reference temperature is used as the target power for heating.

[0069] The maximum discharge power of the battery is the power determined according to the battery temperature and the battery SOC. In another specific embodiment, based on the battery test data and the maximum and minimum voltage limit values, the maximum discharge power at different SOCs can be obtained. By performing battery tests at different temperatures, the relationship between the maximum discharge power of the battery and the temperature and SOC can be established to obtain a maximum discharge power map. Based on the maximum discharge power map, the on-board BMS can obtain the maximum discharge power of the battery by interpolation.

[0070] The reference temperature refers to the temperature at which the battery can discharge at the maximum discharge power under all SOC states. The reference temperature can be set to 25°C to 40°C. Accordingly, the battery maximum discharge power curve at the reference temperature represents the curve of the battery maximum discharge power changing with SOC at the reference temperature.

[0071] According to the vehicle battery heating control method of the embodiment of the present invention, before determining whether the maximum discharge power of the battery is greater than the preset power corresponding to the driving mode (S17), while obtaining the ambient temperature of the vehicle, the battery output power (S11), and obtaining the driving mode of the vehicle and the preset power corresponding to the driving mode (S16), the reference temperature can be pre-set and obtained, and the battery SOC can be obtained (S14). In a specific example, with 25°C as the reference temperature, the battery temperature and the battery SOC can be obtained from the BMS. Subsequently, the maximum discharge power of the battery is determined according to the reference temperature and the battery SOC (S15).

[0072] Re-reference Figure 2 , the vehicle battery heating control method according to the embodiment of the present invention further includes: acquiring the maximum discharge power of the battery, and determining whether the maximum discharge power of the battery is greater than the preset power corresponding to the driving mode (S17). When the maximum discharge power of the battery is greater than the preset power corresponding to the driving mode ("Yes" of S17), it indicates that the SOC of the vehicle is in a high state, and therefore, the first reference power and the second reference power are calculated according to the preset power corresponding to the driving mode (S18), and the heating of the vehicle battery is controlled so that the battery output power is between the first reference power and the second reference power.

[0073] When the maximum discharge power of the battery is less than the preset power corresponding to the driving mode ("No" in S17), it indicates that the SOC of the vehicle is in a low state. The preset power corresponding to the driving mode is a pre-set power for the motor. The main load of the battery in an electric vehicle is the motor. If the maximum discharge power of the battery at a reference temperature (for example, room temperature) cannot meet the power required for the motor drive, it can be determined that the SOC is in a low state. When the SOC of an electric vehicle is in a low state, the battery output power is low. At this time, the battery output power is continuously lower than the power required by the load. In this case, the battery heating (S25) can be directly turned on to avoid damage to the battery caused by low temperature.

[0074] In addition, the maximum discharge power of the battery is used as the second reference power (i.e., the heating off threshold) (S26), and the vehicle battery heating is controlled so that the battery output power is within the second reference power, thereby avoiding excessive heating of the battery and energy waste. Specifically, it is determined whether the battery output power is greater than or equal to the second reference power (S21), and when it is determined that the battery output power is greater than or equal to the second reference power ("Yes" in S21), the battery heating is stopped (S23).

[0075] Figure 4is a schematic diagram showing the heating of the battery according to different heating target powers in the heating control method of the vehicle battery according to an embodiment of the present invention. Taking the vehicle in the sport mode and the reference temperature as 25° C. as an example, Figure 4 In the interval ①, that is, when the SOC gradually consumes from 100% to about 20%, the curve of the maximum discharge power of the battery at 25°C changing with the SOC is located above the straight line indicating the predetermined power (i.e., 120kw) corresponding to the sports mode. This straight line is used as the reference curve, and the battery heating control method uses the calculation result of the preset power as the target power for heating. Figure 4 In interval ②, that is, when the SOC gradually consumes from about 20% to 0%, the curve of the battery's maximum discharge power at 25°C changing with SOC is below the straight line indicating the predetermined power corresponding to the sport mode. This curve is used as a reference curve, and the battery heating control method uses the battery's maximum discharge power curve as the target power for heating.

[0076] Figure 5 : is a graph of battery output power, battery SOC, battery temperature, and battery heating power in the case of using a heating control method for a vehicle battery according to an embodiment of the present invention. Figure 5 As shown, in Figure 5 In the interval ①, the battery heating function is not turned on. As the battery SOC decreases, the battery output power also decreases. Figure 5 In the interval ②, the battery heating power increases from zero to a constant value, that is, the battery heating function is turned on and the battery SOC is high. According to the embodiment of the present invention, the battery temperature continues to rise and the battery output power remains stable. As an example, see Figure 3 The battery output power curve in remains stable within the interval determined by the first reference power and the second reference power. Figure 5 In the interval ③, the battery heating function is turned on, and the battery SOC is low. According to the embodiment of the present invention, the battery temperature continues to rise, but the battery output power also decreases due to the decrease in the battery SOC.

[0077] Re-reference Figure 2 , the heating control method of the vehicle battery according to the embodiment of the present invention provides a battery overheat protection function. The battery temperature is obtained (S27). Specifically, the battery temperature can be obtained from the BMS. More specifically, it is determined whether the battery temperature is less than a preset battery temperature threshold (S22). Those skilled in the art can set a preset battery temperature threshold according to the type, parameters, and performance of the battery. When it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold ("No" of S22), the battery heating is stopped (S23).

[0078] When it is determined that the battery temperature is lower than the preset battery temperature threshold ("Yes" in S22), determine whether the battery output power is greater than or equal to the second reference power (S21). When the battery output power is greater than or equal to the second reference power ("Yes" in S21), stop heating the battery (S23).

[0079] After stopping heating the battery, the battery output power may start to decrease again and become less than the second reference power. If the battery output power continues to decrease below the first reference power, the battery needs to be heated again, and thus the battery may enter a repeated heating process. Figure 3 As shown, repeated heating causes the battery output power to vary between the first reference power and the second reference power, which may cause the torque fluctuation of the vehicle. Therefore, according to a further embodiment of the present invention, in the subsequent battery heating process, the power used for battery insulation and heating in the battery output power can be controlled, so that the downward trend of the battery output power after reaching the second reference power can be slowed down, so that the battery output power remains stable and the torque fluctuation of the vehicle is avoided.

[0080] Figure 6 1 is a flow chart of a heating control method of a vehicle battery when the battery is reheated according to an embodiment of the present invention. Figure 6 As shown, after stopping heating the battery, determine whether the battery output power is less than the second reference power (S31). When the battery output power is greater than or equal to the second reference power ("No" of S31), the battery heating is still stopped (S36). In the case where the battery output power is less than the second reference power ("Yes" of S31), determine whether the battery temperature is less than the preset battery temperature threshold (S32). When it is determined that the battery temperature is less than the preset battery temperature threshold ("Yes" of S32), calculate the difference in the average battery output power in adjacent preset time periods, and increase or decrease the battery insulation and heating power based on the above difference. The battery temperature threshold in step S32 may be different from the battery temperature threshold in S22.

[0081] When the difference between the average battery output power in a preset time period and the average battery output power in the next preset time period is greater than zero ("Yes" in S33), the heating control method for the vehicle battery according to the embodiment of the present invention increases the battery insulation and heating power by the difference (S34). When the difference between the average battery output power in a preset time period and the average battery output power in the next preset time period is less than or equal to zero ("No" in S33), the heating control method for the vehicle battery according to the embodiment of the present invention reduces the battery insulation and heating power by the difference (S35). Since the battery output power is the power that meets the normal operation requirements of various loads in the vehicle, the battery output power can be kept stable by adjusting the power used for battery insulation and heating in the battery output power. Therefore, the initial battery heating stabilizes the battery output power between the first reference power and the second reference power, and the subsequent control of the battery insulation and heating power can further reduce the fluctuation of the battery output power, thereby avoiding the repeated heating process and avoiding the torque fluctuation of the vehicle.

[0082] In a specific example, the battery insulation and heating power may be the power provided in the battery output power to PTC heating, heating film heating, resistance wire heating, liquid heating or pulse heating.

[0083] When it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold (“No” in S32 ), the battery heating is stopped for the purpose of battery overheat protection ( S36 ).

[0084] In a specific implementation, the vehicle battery heating control method may be implemented according to a vehicle control unit (VCU).

[0085] According to another embodiment of the present invention, a heating control device for a vehicle battery is provided. Figure 7 is a block diagram of a heating control device for a vehicle battery according to an embodiment of the present invention. Figure 7 As shown, the heating control device for the vehicle battery may include a receiver and a controller. The receiver may be configured to: obtain the ambient temperature of the vehicle and the battery output power. The receiver may be further configured to: obtain the reference temperature, the battery temperature of the vehicle, and the battery SOC; obtain the driving mode of the vehicle and the preset power corresponding to the driving mode. In a specific embodiment, the receiver may obtain the ambient temperature of the vehicle from the DATC system, and may obtain the battery output power, battery temperature, and battery SOC from the BMS. The receiver may obtain the driving mode of the vehicle by obtaining the state of the driving mode selection switch.

[0086] The controller can be configured to: determine whether the ambient temperature is less than a preset ambient temperature threshold; when it is determined that the ambient temperature is less than the preset ambient temperature threshold, determine whether the battery heating setting is turned on; when it is determined that the battery heating setting is turned on, control the vehicle battery heating so that the battery output power is between a first reference power and a second reference power.

[0087] On the contrary, when it is determined that the ambient temperature is greater than or equal to the preset ambient temperature threshold, the controller does not heat the battery; when it is determined that the ambient temperature is less than the preset ambient temperature threshold, when it is determined that the battery heating setting is turned off, the controller does not heat the battery.

[0088] According to an embodiment of the present invention, the battery output power may be a maximum value of the battery output power within a reference time period.

[0089] The controller can be further configured to: determine the maximum discharge power of the battery based on the reference temperature and the battery SOC; determine whether the maximum discharge power of the battery is greater than a preset power corresponding to the driving mode; when the maximum discharge power of the battery is greater than the preset power corresponding to the driving mode, calculate a first reference power and a second reference power, and control the vehicle battery heating so that the battery output power is between the first reference power and the second reference power.

[0090] Specifically, the controller may be configured to: when controlling the heating of the vehicle battery so that the battery output power is between the first reference power and the second reference power, determine whether the battery output power is less than the first reference power, and when it is determined that the battery output power is less than the first reference power, heat the battery, and during the battery heating process, determine whether the battery temperature is greater than or equal to a preset battery temperature threshold, and when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold, stop the battery heating. When it is determined that the battery temperature is less than the preset battery temperature threshold, determine whether the battery output power is greater than or equal to the second reference power, and when it is determined that the battery output power is greater than or equal to the second reference power, stop the battery heating.

[0091] The controller can calculate the first reference power and the second reference power according to the following formula:

[0092] The first reference power = (motor power + air conditioner power + low voltage electrical appliance power) × the first factor

[0093] Second reference power = (motor power + air conditioner power + low voltage electrical appliance power) × second factor

[0094] The power of the motor may be a preset power corresponding to the driving mode of the vehicle. The current driving mode of the vehicle may include a normal mode, an economic mode, and a sports mode. The first factor may be 1.1, and the second factor may be 1.2.

[0095] The controller can be further configured to heat the battery when the maximum discharge power of the battery is less than a preset power corresponding to the driving mode, use the maximum discharge power of the battery as a second reference power, and control the vehicle battery heating so that the battery output power is within the second reference power.

[0096] Specifically, the controller can be configured as follows: when controlling the vehicle battery heating so that the battery output power is at a second reference power, determining whether the battery temperature is greater than or equal to a preset battery temperature threshold, and when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold, stopping the battery heating; when it is determined that the battery temperature is less than the preset battery temperature threshold, determining whether the battery output power is greater than or equal to the second reference power, and when it is determined that the battery output power is greater than or equal to the second reference power, stopping the battery heating.

[0097] The controller may be further configured to: after stopping heating the battery, determine whether the battery output power is less than the second reference power; when the battery output power is less than the second reference power, calculate the difference between the average battery output powers in adjacent preset time periods, and increase or decrease the battery insulation and heating power based on the difference. Specifically, when the difference between the average battery output power in a preset time period and the average battery output power in the next preset time period is greater than zero, the controller increases the battery insulation and heating power by the difference; when the difference between the average battery output power in a preset time period and the average battery output power in the next preset time period is less than or equal to zero, the controller decreases the battery insulation and heating power by the difference.

[0098] In addition, the controller may be further configured to: during the process of heating the battery, determine whether the battery temperature is greater than or equal to a preset battery temperature threshold, and stop the battery heating when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold.

[0099] According to an embodiment of the present invention, in order to improve the economy and performance of new energy vehicles (NEV) in low temperature climates, a heating control method and device for a vehicle battery are provided. The heating control method and device for a vehicle battery determine the battery heating condition according to the vehicle external ambient temperature, battery temperature, battery SOC, battery maximum discharge power, and battery output power, so that the battery output power is maintained within a range determined by a first reference power (i.e., a heating on threshold) and a second reference power (i.e., a heating off threshold) to reduce fluctuations in the battery output power, thereby improving the driving experience.

[0100] The first reference power and the second reference power are set using different output value targets according to the battery SOC, so as to adapt to the influence of the state change of the battery SOC on the battery performance. When the SOC of the vehicle is high, the calculation result of the preset power is used as the output value target of the heating, and when the SOC of the vehicle is low, the battery maximum discharge power curve is used as the output value target of the heating.

[0101] Different preset powers used as the heating on threshold and the heating off threshold are set for different driving modes (normal mode, economy mode or sport mode).

[0102] In fact, the battery heating structure has not changed. The battery heating is controlled by a new logic so that the battery can be heated to different states. In sports mode, the battery output power can be kept as consistent as possible with the battery output power at normal temperature. In normal mode, the AER value at -7°C can be extended. In economy mode, the vehicle can travel farther in winter. Different battery output power curves can be obtained in different driving modes, so that the driver's driving experience in different driving modes can be distinguished, that is, the driver can also clearly feel the different torque output in winter.

[0103] After stopping heating the battery, in order to slow down the drop in battery output power, the "temperature maintenance" function is enabled to further reduce the fluctuation of battery output power, thereby avoiding repeated heating processes and avoiding vehicle torque fluctuations.

[0104] The various embodiments of the invention are not an exhaustive list of all possible combinations, but are intended to describe representative aspects of the invention, and what is described in various embodiments may be applied independently or in combinations of two or more.

[0105] The description presented in the above exemplary embodiments is only used to illustrate the technical solution of the present invention, and is not intended to be exhaustive, nor is it intended to limit the present invention to the precise form described. Obviously, it is possible for a person of ordinary skill in the art to make many changes and variations based on the above teachings. The exemplary embodiments are selected and described to explain the specific principles of the present invention and its practical application, so that other technicians in the field can easily understand, implement and use the various exemplary embodiments of the present invention and its various selected forms and modified forms. The scope of protection of the present invention is intended to be limited by the attached claims and their equivalent forms.

Claims

1. A heating control method for a vehicle battery, The following steps are involved: Obtain the vehicle's ambient temperature and battery output power through the receiver; Determine, by the controller, whether the ambient temperature is less than a preset ambient temperature threshold; When it is determined that the ambient temperature is less than a preset ambient temperature threshold, determining, by the controller, whether a battery heating setting is turned on; as well as When it is determined that the battery heating setting is turned on, the vehicle battery heating is controlled by the controller so that the battery output power is between the first reference power and the second reference power.

2. The vehicle battery heating control method according to claim 1, further comprising: The following steps are involved: Acquire reference temperature, battery temperature and battery SOC of the vehicle through a receiver; The controller determines the maximum discharge power of the battery according to the reference temperature and the battery SOC; Acquire a driving mode of the vehicle and a preset power corresponding to the driving mode through a receiver; determining, by a controller, whether the maximum discharge power of the battery is greater than a preset power corresponding to the driving mode; When the maximum discharge power of the battery is greater than the preset power corresponding to the driving mode, the controller calculates the first reference power and the second reference power; as well as The vehicle battery is heated by controlling the controller so that the battery output power is between a first reference power and a second reference power.

3. The vehicle battery heating control method according to claim 2, in, Controlling vehicle battery heating so that the battery output power is between a first reference power and a second reference power comprises the following steps: Determining, by a controller, whether the battery output power is less than a first reference power; When it is determined that the battery output power is less than the first reference power, heating the battery through the controller; During the process of heating the battery, determining, by the controller, whether the battery temperature is greater than or equal to a preset battery temperature threshold; When it is determined that the battery temperature is greater than or equal to a preset battery temperature threshold, the battery heating is stopped by the controller; When it is determined that the battery temperature is less than a preset battery temperature threshold, determining, by a controller, whether the battery output power is greater than or equal to a second reference power; and When it is determined that the battery output power is greater than or equal to the second reference power, the battery heating is stopped by the controller.

4. The vehicle battery heating control method according to claim 3, in, The first reference power and the second reference power are calculated according to the following formula: The first reference power = (motor power + air conditioner power + low voltage electrical appliance power) × the first factor; The second reference power = (motor power + air conditioner power + low voltage electrical appliance power) × the second factor; The power of the motor is a preset power corresponding to the driving mode of the vehicle.

5. The vehicle battery heating control method according to claim 4, in, The driving modes of the vehicle include normal mode, economic mode and sports mode; The first factor is 1.1 and the second factor is 1.

2.

6. The vehicle battery heating control method according to claim 2, further comprising: The following steps are involved: When the maximum discharge power of the battery is less than the preset power corresponding to the driving mode, the battery is heated by the controller; as well as The controller uses the maximum discharge power of the battery as the second reference power, and controls the vehicle battery heating to make the battery output power within the second reference power.

7. The vehicle battery heating control method according to claim 6, in, Controlling vehicle battery heating so that the battery output power is within a second reference power includes the following steps: During the process of heating the battery, determining, by the controller, whether the battery temperature is greater than or equal to a preset battery temperature threshold; When it is determined that the battery temperature is greater than or equal to a preset battery temperature threshold, the battery heating is stopped by the controller; When it is determined that the battery temperature is less than a preset battery temperature threshold, determining, by a controller, whether the battery output power is greater than or equal to a second reference power; When it is determined that the battery output power is greater than or equal to the second reference power, the battery heating is stopped by the controller.

8. The vehicle battery heating control method according to claim 1, further comprising: The following steps are involved: When it is determined that the ambient temperature is greater than or equal to a preset ambient temperature threshold, the controller does not heat the battery; as well as In the case where it is determined that the ambient temperature is less than the preset ambient temperature threshold, when it is determined that the battery heating setting is turned off, the battery heating is not performed by the controller.

9. The vehicle battery heating control method according to claim 1, in, The battery output power is the maximum value of the battery output power within a reference time period.

10. The vehicle battery heating control method according to claim 1, in, The method further comprises the following steps: After stopping heating the battery, determining, by the controller, whether the battery output power is less than a second reference power; When the battery output power is less than the second reference power, the controller calculates the difference between the average battery output powers in adjacent preset time periods; and The controller increases or decreases the battery insulation heating power based on the difference.

11. The vehicle battery heating control method according to claim 10, further comprising: The following steps are involved: When the difference between the average battery output power in a preset time period and the average battery output power in a next preset time period is greater than zero, the battery heat preservation and heating power is increased by the difference through the controller; as well as When the difference between the average battery output power in a preset time period and the average battery output power in a next preset time period is less than or equal to zero, the battery heat preservation and heating power is reduced by the difference through the controller.

12. The vehicle battery heating control method according to claim 11, in, The method further comprises the following steps: during the process of heating the battery, determining by a controller whether the battery temperature is greater than or equal to a preset battery temperature threshold; and When it is determined that the battery temperature is greater than or equal to a preset battery temperature threshold, the battery heating is stopped by the controller.

13. A heating control device for a vehicle battery, the device include: The receiver is configured to: obtain the ambient temperature and battery output power of the vehicle; The controller is configured as: Determine whether the ambient temperature is less than a preset ambient temperature threshold; When it is determined that the ambient temperature is less than a preset ambient temperature threshold, determining whether a battery heating setting is turned on; When it is determined that the battery heating setting is turned on, the vehicle battery heating is controlled so that the battery output power is between the first reference power and the second reference power.

14. The heating control device for a vehicle battery according to claim 13, in, The receiver is further configured to: Obtain reference temperature, battery temperature and battery SOC of the vehicle; Acquire a driving mode of the vehicle and a preset power corresponding to the driving mode; The controller is further configured to: Determine the maximum discharge power of the battery according to the reference temperature and the battery SOC; determining whether the maximum discharge power of the battery is greater than a preset power corresponding to the driving mode; When the maximum discharge power of the battery is greater than the preset power corresponding to the driving mode, a first reference power and a second reference power are calculated, and the vehicle battery is heated so that the battery output power is between the first reference power and the second reference power.

15. The heating control device for a vehicle battery according to claim 14, in, When controlling the vehicle battery heating so that the battery output power is between the first reference power and the second reference power, the controller is configured as follows: determining whether the battery output power is less than a first reference power; When it is determined that the battery output power is less than the first reference power, heating the battery; During the process of heating the battery, determining whether the battery temperature is greater than or equal to a preset battery temperature threshold; When it is determined that the battery temperature is greater than or equal to a preset battery temperature threshold, stopping the battery heating; When it is determined that the battery temperature is less than a preset battery temperature threshold, determining whether the battery output power is greater than or equal to a second reference power; When it is determined that the battery output power is greater than or equal to the second reference power, the battery heating is stopped.

16. The heating control device for a vehicle battery according to claim 15, in, The controller is configured to calculate the first reference power and the second reference power according to the following formula: The first reference power = (motor power + air conditioner power + low voltage electrical appliance power) × the first factor; The second reference power = (motor power + air conditioner power + low voltage electrical appliance power) × the second factor; The power of the motor is a preset power corresponding to the driving mode of the vehicle.

17. The heating control device for a vehicle battery according to claim 16, in, The driving modes of the vehicle include normal mode, economic mode and sports mode; The first factor is 1.1 and the second factor is 1.

2.

18. The heating control device for a vehicle battery according to claim 14, in, The controller is configured as follows: When the maximum discharge power of the battery is less than the preset power corresponding to the driving mode, the battery is heated, and the maximum discharge power of the battery is used as the second reference power to control the vehicle battery heating so that the battery output power is within the second reference power.

19. The heating control device for a vehicle battery according to claim 18, in, When controlling the vehicle battery heating so that the battery output power is within the second reference power, the controller is configured as follows: determining whether the battery temperature is greater than or equal to a preset battery temperature threshold, and stopping the battery heating when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold; When it is determined that the battery temperature is less than a preset battery temperature threshold, it is determined whether the battery output power is greater than or equal to a second reference power. When it is determined that the battery output power is greater than or equal to the second reference power, the battery heating is stopped.

20. The heating control device for a vehicle battery according to claim 13, in, The controller is configured as follows: When it is determined that the ambient temperature is greater than or equal to a preset ambient temperature threshold, the battery is not heated; In the case where it is determined that the ambient temperature is less than the preset ambient temperature threshold, when it is determined that the battery heating setting is turned off, the battery heating is not performed.

21. The heating control device for a vehicle battery according to claim 13, in, The battery output power is the maximum value of the battery output power within a reference time period.

22. The heating control device for a vehicle battery according to claim 13, in, The controller is further configured to: After stopping heating the battery, determining whether the battery output power is less than a second reference power; as well as When the battery output power is less than the second reference power, the difference between the average battery output powers in adjacent preset time periods is calculated, and the battery heat preservation and heating power is increased or decreased based on the difference.

23. The heating control device for a vehicle battery according to claim 22, in, The controller is configured as follows: When the difference between the average battery output power in a preset time period and the average battery output power in a next preset time period is greater than zero, the battery heat preservation and heating power is increased by the difference; When the difference between the average battery output power in a preset time period and the average battery output power in a next preset time period is less than or equal to zero, the battery heat preservation and heating power is reduced by the difference.

24. The heating control device for a vehicle battery according to claim 23, in, The controller is further configured to: during the process of heating the battery, determine whether the battery temperature is greater than or equal to a preset battery temperature threshold, and stop the battery heating when it is determined that the battery temperature is greater than or equal to the preset battery temperature threshold.

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