V2x-based electric vehicle combined working condition battery temperature control method and system

Abstract

The application discloses a V2X-based electric vehicle combined working condition battery temperature control method and system, and relates to the technical field of intelligent transportation and new energy vehicles. The method comprises the following steps: obtaining the current temperature and state of charge of the vehicle battery, and obtaining the road information within a first preset distance in front of the vehicle through V2X communication; based on the road information, identifying whether there is a combined working condition composed of a downhill section and a tunnel section in front of the vehicle; when the combined working condition is identified, predicting the expected temperature change of the battery of the vehicle within the duration of the combined working condition based on the current temperature, state of charge and road information of the vehicle battery; when the vehicle travels to a preset pre-scheduling trigger distance from the starting position of the combined working condition, performing a thermal management pre-scheduling operation on the battery based on the expected temperature change and a dynamically determined preset working temperature interval. The application changes the thermal management from passive lag response to active foresight defense, improving the thermal safety and energy efficiency of the battery under complex road conditions.

Description

Technical Field

[0001] This invention relates to the fields of intelligent transportation and new energy vehicle technology, and in particular to a method and system for controlling battery temperature under combined operating conditions of electric vehicles based on V2X. Background Technology

[0002] In electric vehicle thermal management, complex road conditions such as long downhill slopes in mountainous areas and tunnels significantly increase the thermal load on batteries. When a vehicle is continuously descending a slope, the energy recovery braking system keeps the battery in a high-power charging state for an extended period, leading to a rapid increase in heat. Meanwhile, poor airflow in tunnels severely weakens the battery's heat dissipation capacity. In actual roads, long downhill slopes and tunnels often alternate continuously in space, causing the peak of battery heat generation and the deterioration of heat dissipation conditions to highly overlap in time, forming a compound thermal shock that can easily trigger battery overheating.

[0003] Currently, electric vehicle battery thermal management systems generally rely on local sensors and preset rules for feedback control, lacking the ability to predict information such as road gradients and tunnel distribution. This delayed control often triggers cooling only after the battery has significantly heated up due to high-intensity braking energy recovery, resulting in prolonged high-temperature exposure and adversely affecting battery life and safety. Furthermore, existing strategies often treat long downhill slopes and tunnels as independent operating scenarios, employing fixed start-stop thresholds. When a vehicle sequentially experiences these two conditions, the heat accumulated in the earlier stage cannot dissipate due to the drastically deteriorating cooling environment in the later stage, easily leading to temperature spikes during control switching. In addition, fixed temperature thresholds cannot dynamically adjust cooling intensity based on the severity of road conditions ahead. For example, they cannot suppress the temperature rise trend in advance when approaching a tunnel or other heat-constrained environment, while in open road sections with good cooling conditions, excessive cooling can increase overall vehicle energy consumption. Summary of the Invention

[0004] To address the shortcomings of existing technologies, such as the lack of proactive perception of road conditions ahead, inability to identify combined risks arising from downhill slopes and tunnel connections, and the inability of fixed temperature thresholds to dynamically adapt to changing operating conditions, this invention proposes a V2X-based battery temperature control method and system for electric vehicles operating in combined conditions. This method uses V2X communication to proactively perceive road information, accurately identify combined operating conditions, and predict the expected battery temperature rise. Before entering a combined operating condition, it performs pre-scheduling based on the expected temperature rise and the dynamic operating temperature range, thereby achieving a leap from delayed response to proactive prediction in battery thermal management, improving thermal safety and energy efficiency under complex road conditions.

[0005] The present invention achieves the above objectives through the following technical solutions: A V2X-based battery temperature control method for electric vehicle combination operating conditions includes: The vehicle battery's current temperature and state of charge are obtained, and road information within a first preset distance ahead of the vehicle is obtained via V2X communication. Based on road information, identify whether there is a combination of road conditions consisting of downhill sections and tunnel sections ahead of the vehicle; When a combined operating condition is identified, the expected temperature change of the vehicle's battery during the duration of the combined operating condition is predicted based on the vehicle's current battery temperature, state of charge, and road information. When the vehicle travels to the starting position of the combined operating condition and reaches the preset pre-scheduling trigger distance, the battery performs a thermal management pre-scheduling operation based on the expected temperature change and the preset operating temperature range; the preset operating temperature range is dynamically determined based on road information and includes the upper temperature limit and the lower temperature limit of the preset operating temperature range.

[0006] As a preferred embodiment of the present invention, the method of obtaining road information within a first preset distance in front of the vehicle through V2X communication includes the slope distribution curve and slope length information of long downhill road sections, the tunnel length and ventilation information of tunnel sections, and the radius of curvature and traffic flow density information of the road.

[0007] As a preferred embodiment of the present invention, the step of identifying whether there is a combined road condition consisting of a downhill section and a tunnel section ahead of the vehicle includes: Determine whether the distance between the toe of the downhill section and the entrance of the tunnel section is less than a second preset distance threshold; When the distance is less than the second preset distance threshold, the long downhill section and the tunnel section are determined to form a combined working condition, and the starting position of the downhill section is defined as the starting position of the combined working condition.

[0008] As a preferred embodiment of the present invention, the prediction of the expected temperature change of the battery during the duration of combined operating conditions of the vehicle includes: Obtain the initial time when the vehicle enters the combined operating condition and the expected termination time when it exits the combined operating condition; calculate the cumulative net heat generation of the vehicle under the combined operating condition using the following formula: ; in, To accumulate net heat production; This refers to the initial moment when the vehicle enters the combined operating condition. The termination time of exiting the combined operating condition; For the battery Net heat output at any given moment; Based on the cumulative net heat generation, battery mass, and battery specific heat capacity, the temperature change of the battery under combined operating conditions is calculated using the following formula: ; in, This refers to the change in temperature. To accumulate net heat production; For the quality of the battery; This refers to the specific heat capacity of the battery. Based on the temperature change and the current battery temperature, the expected maximum temperature of the battery is predicted.

[0009] As a preferred embodiment of the present invention, the calculation of the net heat power output includes: Based on downhill road parameters, the braking regeneration heat power of the vehicle on the downhill road is obtained, and the basic heat dissipation power of the battery is obtained based on the current vehicle speed. Based on the tunnel length and the wind speed inside the tunnel, the heat dissipation reduction factor for vehicles in the tunnel section is calculated using the following formula: ; in, This is the heat dissipation reduction factor; The preset maximum heat dissipation attenuation ratio; This refers to the tunnel length; Preset reference tunnel length; is the base of the natural logarithm; Wind speed inside the tunnel; Preset reference wind speed; Based on the regenerative braking heat generation power, the basic heat dissipation power, and the heat dissipation reduction factor, the battery's performance is calculated. The net heat output at any given time is calculated using the following formula:

[0010] ; in, Net heat output; To recover the heat generated during braking; This is the heat dissipation reduction factor; Based on the heat dissipation power.

[0011] As a preferred embodiment of the present invention, the step of obtaining the regenerative braking heat generation power of the vehicle on the downhill section based on downhill road parameters includes: Based on the current absolute slope angle, current vehicle speed, and vehicle mass, calculate the downhill driving power provided by gravity along the slope direction. The calculation formula is as follows: ; in, This is the downhill drive power; For the overall vehicle weight; It is the acceleration due to gravity; Current vehicle speed; This is the absolute angle value of the slope; Based on the downhill driving power and the driving resistance power required to maintain the current vehicle speed, the regenerative braking power is determined using the following formula: ; in, Recoverable braking power; Power is the driving resistance. Based on the recyclable braking power, the motor's power generation efficiency, the battery's internal charging resistance, and the battery's current voltage, the braking heat recovery power is calculated using the following formula: ; in, To recover the heat generated during braking; The power generation efficiency of the motor; This is the current battery voltage. The internal resistance of the battery during charging; To recover electrical power for braking; The method of obtaining the battery's basic heat dissipation power based on the current vehicle speed includes: Obtain the current battery temperature, ambient temperature, and current vehicle speed; Based on the current vehicle speed, the equivalent convective heat transfer coefficient of the battery casing surface is calculated using the following formula: ; in, This is the equivalent convective heat transfer coefficient; The coefficient of heat transfer is the natural convection heat transfer coefficient. This is the wind speed enhancement coefficient; Based on the equivalent convective heat transfer coefficient, the current battery temperature, and the ambient temperature, the basic heat dissipation power is calculated using the following formula: ; in, Basic heat dissipation power; The equivalent area for convective heat transfer between the battery and the air; This refers to the current temperature of the battery. The ambient temperature.

[0012] As a preferred embodiment of the present invention, the preset operating temperature range is dynamically determined based on road information, including: Based on the slope value of the long downhill section, determine the upper limit of the basic temperature threshold corresponding to the slope value; Based on the tunnel length, the length correction amount for the upper limit of the base temperature threshold is calculated using the following formula: ; in, This is the length correction amount; It is a negative constant; Preset reference tunnel length; Based on the upper limit of the basic temperature threshold and the length correction amount, the upper limit of the corrected preset operating temperature range is determined by the following formula: ; in, The upper limit of the preset operating temperature range; The upper limit of the base temperature threshold; The lower limit of the preset operating temperature range is the preset minimum operating temperature.

[0013] As a preferred embodiment of the present invention, the step of performing thermal management pre-scheduling operations on the battery includes: Based on the end point of the downhill section and the start point of the tunnel section in the combined working condition, the combined working condition is divided into an entrance section, a middle section, and an exit section. The entrance section covers the area from the current vehicle position to the start point of the combined working condition. The middle section covers the area from the start point of the combined working condition to the end point of the tunnel section. The exit section covers the area extending forward from the end point of the tunnel section by a second preset length. The system acquires the current temperature of the vehicle battery, the heat generated by regenerative braking, the direction signal of the vehicle's power battery bus current, and the upper limit of the preset operating temperature range. It then calculates the target temperature for the inlet section using the following formula: ; in, The target temperature for the inlet section; The upper limit of the preset operating temperature range; This is to allow for a safety margin in the inlet section temperature. When the distance between the vehicle and the starting point of the combined operating condition is greater than or equal to the preset pre-scheduling trigger distance, the battery thermal management system is controlled to adjust the battery temperature to the target temperature of the inlet section. When the absolute value of the difference between the current temperature of the vehicle battery and the target temperature of the inlet section is less than the preset convergence threshold, the pre-temperature adjustment is determined to be completed. When the vehicle enters the middle section, based on the current temperature of the vehicle battery, the heat generated by regenerative braking and the heat dissipation reduction coefficient, the battery temperature of the next cycle is predicted according to the control cycle. Based on the comparison between the battery temperature of the next cycle and the upper limit of the preset operating temperature range and the lower limit of the preset operating temperature range, the cooling power of the battery thermal management system is adaptively controlled. When the vehicle enters the exit section, the battery thermal management system is controlled to cool to the target temperature of the exit section. The calculation formula is as follows: ; in, The target temperature for the outlet section; This is the preset temperature buffer amount for the outlet section.

[0014] As a preferred embodiment of the present invention, the adaptive control of the cooling power of the battery thermal management system based on the comparison result between the battery temperature of the next cycle and the upper limit of the preset operating temperature range and the lower limit of the preset operating temperature range includes: When the current direction signal of the power battery bus is charging and the regenerative braking power is greater than the preset regenerative power threshold, it is determined to be an energy recovery working condition. The battery temperature for the next cycle is compared with the upper limit and lower limit of the preset operating temperature range; the formula for calculating the battery temperature for the next cycle is: ; in, The battery temperature for the next cycle; To control cycle duration; If the battery temperature in the next cycle exceeds the upper limit of the preset operating temperature range, the cooling power of the battery thermal management system will be increased. The formula for calculating the increase in cooling power is as follows: ; in, This represents the increase in cooling power. This is the preset proportional control coefficient; The upper limit of the preset operating temperature range; If the battery temperature in the next cycle is lower than the lower limit of the preset operating temperature range, and the condition is determined to be energy recovery mode, then the cooling power of the battery thermal management system will be reduced. The reduction in cooling power will be: ; in, This represents the reduction in cooling power. The preset power relaxation factor; The lower limit of the preset operating temperature range; if the cooling power is reduced to zero and still cannot meet the heating requirement, the heating function will be activated. If the battery temperature in the next cycle is lower than the lower limit of the preset operating temperature range and is not determined to be an energy recovery condition, the current cooling power will remain unchanged. If the battery temperature in the next cycle is greater than or equal to the lower limit of the preset operating temperature range, but less than or equal to the upper limit of the preset operating temperature range, then the current cooling power will remain unchanged.

[0015] A V2X-based battery temperature control system for electric vehicle combinations includes: The information acquisition module is used to acquire the current temperature and state of charge of the vehicle battery, and to acquire road information within a first preset distance in front of the vehicle through V2X communication; The combined working condition recognition module is used to identify, based on road information, whether there is a combined working condition in front of the vehicle consisting of a downhill section and a tunnel section; The battery temperature prediction module is used to predict the expected temperature change of the vehicle's battery during the duration of the combined operating conditions based on the current temperature of the vehicle's battery, state of charge, and road information when a combined operating condition is identified. The thermal management pre-scheduling module is used to perform thermal management pre-scheduling operations on the battery based on the expected temperature change and the preset operating temperature range when the vehicle travels to the starting position of the combined operating conditions and reaches the preset pre-scheduling trigger distance. The preset operating temperature range is dynamically determined based on road information and includes the upper temperature limit and the lower temperature limit of the preset operating temperature range.

[0016] The beneficial effects of this invention are as follows: By acquiring road information ahead of the vehicle in advance through V2X communication, it breaks through the lagging response mode of traditional thermal management that relies solely on local sensor feedback, shifting the triggering time for thermal management decisions from post-event response to pre-event prediction, thus gaining crucial pre-aiming time for proactive cooling intervention; Based on the prior information about the road ahead, it innovatively identifies combined operating conditions consisting of downhill sections and tunnel sections, unifying the two isolated scenarios in existing technologies into a continuous risk whole, filling the gap in thermal management blind spots at the operating condition transition points, and laying a clear boundary for subsequent accurate prediction and proactive control; After identifying the combined operating condition, it integrates the vehicle's current battery status and road information ahead to predict the expected temperature change of the battery during the duration of the combined operating condition, realizing a leap from passive adjustment based on current temperature to proactive extrapolation based on future operating conditions, providing a quantitative decision-making basis for thermal management pre-scheduling; When the vehicle approaches the starting point of the combined operating condition and reaches the preset pre-scheduling trigger distance, the pre-scheduling operation is performed based on the expected temperature change and the dynamically determined preset operating temperature range. The preceding capabilities formed by perception, identification and prediction are uniformly transformed into real-time control actions, which actively intervene before the risk of battery temperature rise runaway is formed. This fundamentally resolves the contradiction between temperature rise runaway and overcooling under combined operating conditions, and takes into account the dual goals of thermal safety and energy efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart of the battery temperature control method for electric vehicle combination operating conditions based on V2X proposed in this invention; Figure 2This is a schematic diagram of the modular structure of the V2X-based battery temperature control system for electric vehicles under combined operating conditions proposed in this invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, this is an embodiment of the present invention, which provides a method for controlling battery temperature under V2X-based electric vehicle combined operating conditions, including: S1, obtain the current temperature and state of charge of the vehicle battery, and obtain road information within a first preset distance in front of the vehicle through V2X communication.

[0020] Among them, road information within a first preset distance in front of the vehicle is obtained through V2X communication, including the slope distribution curve and slope length information of long downhill road sections, the tunnel length and ventilation information of tunnel sections, as well as the curvature radius and traffic flow density information of the road.

[0021] Specifically, the current temperature and state of charge (SOC) of the vehicle battery are acquired in real time by the vehicle's local battery management system and transmitted to the vehicle controller or thermal management controller via the onboard CAN bus at fixed intervals. The current battery temperature can be the highest value collected by all temperature sensors within the battery pack, or the temperature of the most unfavorable cell selected according to thermal management control requirements; the SOC is estimated in real time by the battery management system using an ampere-hour integration algorithm combined with an open-circuit voltage correction algorithm. In one specific embodiment, the fixed interval is set to 100ms.

[0022] The vehicle controller receives road information from roadside units, other vehicles, or cloud platforms via the onboard V2X communication unit. In one specific embodiment, a direct communication connection is established using an LTE-V2X PC5 interface, and the onboard V2X communication unit periodically listens to the message sets broadcast by the roadside units. The first preset distance is set to 2000 meters ahead of the vehicle's current position, and can be dynamically adjusted according to vehicle speed. When the vehicle speed exceeds 80 km / h, it can be extended to 3000 meters to ensure sufficient pre-aiming time.

[0023] The slope distribution curve and slope length information for long downhill sections are extracted from high-precision map data or dedicated road attribute messages broadcast by roadside units. The slope distribution curve is represented as a discrete sequence, with each sequence point containing the longitudinal distance and slope value relative to the starting point. The slope value is expressed as a percentage, with positive values ​​indicating uphill and negative values ​​indicating downhill. The slope length information is the total length of the downhill section.

[0024] The tunnel length is extracted directly from the high-precision map broadcast by the roadside unit, or calculated based on the tunnel start and end mileage carried in the road attribute messages broadcast by the roadside unit. Ventilation information includes the ambient wind speed and fan operating status inside the tunnel. The ambient wind speed can be collected by meteorological sensors inside the tunnel and broadcast by the roadside unit, or the wind speed at the tunnel entrance can be referenced. This information is used to quantify the degree to which the tunnel section reduces battery heat dissipation.

[0025] The road curvature radius information is obtained through the path curvature attribute of a high-precision map, or approximated by the rate of change of heading angle, and is used to estimate the vehicle's speed limit at curves, thereby more accurately predicting the duration and intensity of regenerative braking power.

[0026] Traffic flow density information is obtained from traffic flow messages sent by roadside units or real-time traffic services pushed by cloud platforms, typically represented by vehicle density or the average travel speed of the current road segment. Traffic flow density directly affects the actual feasible speed of vehicles on downhill and tunnel sections, which in turn affects regenerative braking power and natural heat dissipation conditions, and therefore needs to be included in temperature rise prediction.

[0027] When the vehicle-mounted V2X communication unit fails to receive valid road information for three consecutive cycles, it is determined that the V2X communication is interrupted and automatically switches to offline mode. The vehicle uses a pre-stored high-precision map to obtain information on road slope distribution, slope length, tunnel length and radius of curvature. Traffic flow density and tunnel ventilation information are estimated using historical statistical data, and the confidence level of the estimation result is marked as a preset value, such as 0.7. Subsequent thermal management pre-scheduling operations will appropriately increase the temperature safety margin.

[0028] The acquired road information is parsed and stored in the vehicle controller's memory in the form of structured data objects. Each waypoint contains fields such as distance from the starting point, gradient, radius of curvature, tunnel marker, wind speed, and current traffic density.

[0029] By acquiring road information ahead through V2X, road geometry and environmental characteristics can be perceived in advance, providing an accurate basis for proactive thermal management pre-scheduling and solving the shortcomings of traditional methods that rely solely on onboard sensors and cannot predict the working conditions ahead.

[0030] S2, based on road information, identifies whether there is a combination of road conditions in front of the vehicle consisting of a downhill section and a tunnel section.

[0031] Among these, identifying whether there is a combined road condition ahead of the vehicle consisting of a downhill section and a tunnel section includes: Determine whether the distance between the toe of the downhill section and the entrance of the tunnel section is less than a second preset distance threshold.

[0032] When the distance is less than the second preset distance threshold, the long downhill section and the tunnel section are determined to form a combined working condition, and the starting position of the downhill section is defined as the starting position of the combined working condition.

[0033] Specifically, the top of the slope is the starting point of the downhill section, that is, the inflection point where the slope changes from flat or uphill to continuous downhill; the bottom of the slope is the ending point of the downhill section, that is, the inflection point where the slope changes from continuous downhill to flat or uphill; the tunnel entrance is the starting mileage of the tunnel section; and the tunnel exit is the ending mileage of the tunnel section.

[0034] The specific identification process is as follows: The system iterates through the waypoint sequence, identifying valid downhill sections based on consecutively negative slope values ​​and absolute slope values ​​exceeding a preset minimum slope threshold. To avoid misclassifying short-lived undulations, a long downhill identification condition is also set: when the slope length of a section is greater than or equal to a preset minimum slope length, and the average slope is greater than or equal to a preset average slope threshold, the section is determined to be a valid long downhill section with significant heat accumulation risk. The last waypoint location of this section is recorded as the slope toe position. Simultaneously, based on the tunnel marker field of the waypoints, the first waypoint marked "yes" for a tunnel is identified and recorded as the tunnel entrance position. The distance between the slope toe position of the downhill section and the tunnel entrance position is calculated.

[0035] Determine whether the distance between the toe of the downhill section and the entrance of the tunnel section is less than a second preset distance threshold. If the distance is less than the second preset distance threshold, determine that the downhill section and the tunnel section form a combined working condition, define the top of the downhill section as the starting point of the combined working condition, and define the exit of the tunnel section as the ending point of the combined working condition.

[0036] When multiple downhill sections and tunnels intersect, the structured waypoint data is arranged in ascending order of mileage. Priority is given to pairing the slope foot closest to the current vehicle with the first tunnel entrance to form an independent combination of conditions. The remaining unpaired downhill sections and tunnel sections are then judged in turn.

[0037] In one specific embodiment, the preset minimum slope threshold is set to 1%; the preset minimum slope length is set to 500 meters; and the preset average slope threshold is set to 3%. The base value of the second preset distance threshold is set to 500 meters and can be dynamically adjusted based on the current battery temperature, ambient temperature, and information confidence level. When the current battery temperature is greater than or equal to the upper limit of the preset operating temperature range, the second preset distance threshold can be increased to 800 meters to more conservatively identify the risk of superimposed temperature rise; when the current battery temperature is less than or equal to the lower limit of the preset operating temperature range, the second preset distance threshold can be reduced to 300 meters to reduce unnecessary pre-scheduled energy consumption; when the ambient temperature is greater than 35°C, an additional 100 meters is added to the above; when the ambient temperature is less than or equal to 0°C, an additional 100 meters is reduced to the above; if in V2X offline mode and the information confidence level is less than 0.7, the second preset distance threshold directly adopts the conservative value of 800 meters.

[0038] If the vehicle enters the tunnel within the second preset distance threshold after the downhill section ends, the accumulated braking heat from the downhill section will not be fully dissipated before the heat dissipation conditions inside the tunnel deteriorate sharply, and the battery temperature will rise cumulatively. This constitutes the core high-risk combination of working conditions that this invention specifically addresses.

[0039] If the mileage at the tunnel entrance is less than the mileage at the toe of the slope, meaning the tunnel covers part of the downhill section, it is directly classified as a combined working condition. The starting point of the combined working condition is the toe of the slope, and the ending point is the tunnel exit. If there is a flat road of less than or equal to 50 meters in length or a small uphill slope of less than or equal to 1% in the middle of a long downhill section, it is still considered as a continuous long downhill section, and the toe of the slope is taken as the final downhill end point. If there are multiple consecutive tunnels after the toe of the slope, and the distance between adjacent tunnels is less than 50 meters, it is considered as a whole tunnel section. The entrance of the first tunnel is taken as the tunnel entrance position, and the exit of the last tunnel is taken as the end point of the combined working condition.

[0040] S3, when a combined operating condition is identified, predicts the expected temperature change of the vehicle's battery during the duration of the combined operating condition based on the vehicle's current battery temperature, state of charge, and road information.

[0041] Predicting the expected temperature change of the battery during the duration of combined operating conditions, including: Obtain the initial time when the vehicle enters the combined operating condition and the expected termination time when it exits the combined operating condition.

[0042] In one specific embodiment, the initial time The estimated time when the vehicle will reach the starting position of the combined operating condition and the estimated time when it will terminate. This is the estimated time to reach the endpoint of the combined driving condition. The estimated travel time is estimated in segments based on the current vehicle speed and the speed limit information of the upcoming waypoint sequence: the entire combined driving condition is divided into several micro-segments according to waypoints. The travel time for each segment is calculated using the speed limit of that segment and the feasible speed corrected for the current traffic flow density. The feasible speed is the minimum value among the speed limit of that segment, the speed corrected for traffic flow density, and the speed limit for the curve radius. These values ​​are then summed to obtain the total estimated duration. If the current vehicle speed is 80 km / h and the total length of the combined driving condition is 3 km, the estimated duration is 135 seconds; if the traffic flow density is high and the feasible speed drops to 50 km / h, the estimated duration is adjusted to 216 seconds.

[0043] The formula for calculating the cumulative net heat generation of a vehicle under combined operating conditions is as follows: ; in, To accumulate net heat production; This refers to the initial moment when the vehicle enters the combined operating condition. The termination time of exiting the combined operating condition; For the battery Net heat output at any given moment.

[0044] Among them, the battery is The calculation of net heat production power at any given time includes: Based on downhill road parameters, the braking regeneration heat power of the vehicle on the downhill road is obtained, and the basic heat dissipation power of the battery is obtained based on the current vehicle speed.

[0045] Among them, based on the parameters of the downhill section, the braking regeneration heat power of the vehicle on the downhill section is obtained, including: Based on the current absolute slope angle, current vehicle speed, and vehicle mass, calculate the downhill driving power provided by gravity along the slope direction. The calculation formula is as follows: ; in, This is the downhill drive power; For the overall vehicle weight; It is the acceleration due to gravity; Current vehicle speed; This represents the absolute angle value of the slope.

[0046] Specifically, the absolute slope angle value is converted into an angle value by taking the absolute value of the slope percentage of the corresponding waypoint in the obtained slope distribution curve; the vehicle mass is the sum of the vehicle's curb weight and payload, which can be obtained from the vehicle's CAN bus or by using calibration values.

[0047] In one specific embodiment, when the slope percentage is -6%, This ensures that the downhill drive power remains constant at a positive value.

[0048] Based on the downhill driving power and the driving resistance power required to maintain the current vehicle speed, the regenerative braking power is determined using the following formula: ; in, Recoverable braking power; This represents the power generated by the driving resistance.

[0049] Specifically, during downhill driving, a portion of the downhill driving power is used to overcome driving resistance, while the remainder can be recovered through motor braking. Driving resistance power includes rolling resistance power, air resistance power, and transmission resistance power, which is obtained by looking up a table of coasting resistance curves calibrated from vehicle bench tests. The curves have vehicle speed as the independent variable and driving resistance power as the dependent variable. In one specific embodiment, driving resistance power is obtained by looking up a table of vehicle coasting resistance curves.

[0050] When the downhill driving power is less than or equal to the driving resistance power, the downhill driving force is insufficient to overcome the driving resistance, and the vehicle needs to consume electrical energy to maintain its speed. At this time, the regenerative braking power is 0, and no braking heat is generated.

[0051] Based on the recyclable braking power, the motor's power generation efficiency, the battery's internal charging resistance, and the battery's current voltage, the braking heat recovery power is calculated using the following formula: ; in, To recover the heat generated during braking; The power generation efficiency of the motor; This is the current battery voltage. This refers to the internal resistance of the battery during charging.

[0052] Specifically, the current battery voltage is provided in real time by the battery management system via the vehicle's CAN bus; the battery's charging internal resistance is obtained by the battery management system by looking up a table based on the current state of charge and battery temperature.

[0053] In one specific embodiment, the power generation efficiency of the motor is set to 0.85; when the state of charge is 60% and the battery temperature is 25°C, the charging internal resistance of a certain ternary lithium battery is approximately 0.8 mΩ.

[0054] The basic heat dissipation power of the battery, obtained based on the current vehicle speed, includes: Get the current battery temperature, ambient temperature, and current vehicle speed.

[0055] Specifically, the current battery temperature is read from the vehicle's CAN bus, the ambient temperature is read from the vehicle's external temperature sensor, and the current vehicle speed is obtained from the vehicle speed sensor.

[0056] Based on the current vehicle speed, the equivalent convective heat transfer coefficient of the battery casing surface is calculated using the following formula: ; in, This is the equivalent convective heat transfer coefficient; The coefficient of heat transfer is the natural convection heat transfer coefficient. This is the wind speed enhancement coefficient.

[0057] In one specific embodiment, the units for both the natural convection heat transfer coefficient and the equivalent convection heat transfer coefficient are... The natural convection heat transfer coefficient is set to 5. Wind speed enhancement coefficient Used to characterize the enhanced forced convection effect caused by vehicle speed, with units of . Set to 2 The unit of current vehicle speed is .

[0058] Based on the equivalent convective heat transfer coefficient, the current battery temperature, and the ambient temperature, the basic heat dissipation power is calculated using the following formula: ; in, Basic heat dissipation power; The equivalent area for convective heat transfer between the battery and the air; This refers to the current temperature of the battery. The ambient temperature.

[0059] Specifically, the equivalent area is determined by the battery pack geometry and its arrangement. When the current battery temperature is lower than the ambient temperature, the basic heat dissipation power is negative, indicating that the environment is transferring heat to the battery. However, in high-temperature scenarios, the current battery temperature is usually significantly higher than the ambient temperature, and the basic heat dissipation power is positive, indicating that the battery is dissipating heat to the environment.

[0060] In one specific embodiment, the equivalent area is set to 1.8 m².

[0061] Based on the tunnel length and the wind speed inside the tunnel, the heat dissipation reduction factor for vehicles in the tunnel section is calculated using the following formula: ; in, This is the heat dissipation reduction factor; The preset maximum heat dissipation attenuation ratio; This refers to the tunnel length; Preset reference tunnel length; is the base of the natural logarithm; Wind speed inside the tunnel; This is the preset reference wind speed.

[0062] Specifically, the heat dissipation reduction factor represents the remaining proportion of heat dissipation capacity in a tunnel environment. The smaller the heat dissipation reduction factor value, the more severe the reduction in heat dissipation. After a vehicle enters a tunnel, the battery's heat dissipation effect decreases due to restricted airflow and higher temperatures inside the tunnel. This effect is quantified by the heat dissipation reduction factor.

[0063] In one specific embodiment, the preset maximum heat dissipation attenuation ratio is set to 0.60, which means that under the most unfavorable conditions such as long tunnels and low ventilation, the heat dissipation capacity will be reduced by up to 60%; the preset reference wind speed is set to 5.0 m / s; and the preset reference tunnel length is set to 500 meters.

[0064] If the vehicle has not yet entered the tunnel, the heat dissipation reduction factor is forcibly assigned to 1, indicating no heat dissipation reduction and heat dissipation calculation based on normal environment; after entering the tunnel, the heat dissipation reduction factor is calculated in real time according to the above formula.

[0065] Based on the regenerative braking heat generation power, the basic heat dissipation power, and the heat dissipation reduction factor, the battery's performance is calculated. The net heat output at any given time is calculated using the following formula: ; in, Net heat output; To recover the heat generated during braking; This is the heat dissipation reduction factor; Based on the heat dissipation power.

[0066] Specifically, when the heat generated by braking recovery is relatively large, and When the temperature is relatively low, such as during heavy braking downhill or in long tunnels with low ventilation, the net thermal power generated is a large positive value, and the battery heats up rapidly. This is the core thermal risk of the combined operating conditions.

[0067] Based on the cumulative net heat generation, battery mass, and battery specific heat capacity, the temperature change of the battery under combined operating conditions is calculated using the following formula: ; in, This refers to the change in temperature. To accumulate net heat production; For the quality of the battery; This refers to the specific heat capacity of the battery.

[0068] Based on the temperature change and the current battery temperature, the expected maximum temperature of the battery is predicted.

[0069] Specifically, if there are multiple slope or wind speed changes within the prediction period, the maximum value of the predicted temperature for each period is taken as the expected maximum temperature of the battery.

[0070] In one specific embodiment, the expected maximum temperature is the sum of the temperature change and the current battery temperature.

[0071] S4: When the vehicle travels to the starting point of the combined operating condition and reaches the preset pre-scheduling trigger distance, a thermal management pre-scheduling operation is performed on the battery based on the expected temperature change and the preset operating temperature range. The preset operating temperature range is dynamically determined based on road information and includes the upper temperature limit and the lower temperature limit of the preset operating temperature range.

[0072] Traditional batteries typically operate within a fixed temperature range. However, in conditions involving long downhill slopes and tunnels, fixed thresholds cannot balance the risk of heat dissipation deterioration with the requirements for recycling efficiency.

[0073] The preset operating temperature range is dynamically determined based on road information, including: Based on the slope value of the long downhill section, determine the upper limit of the basic temperature threshold corresponding to the slope value.

[0074] In one specific embodiment, the upper limit of the base temperature threshold corresponds one-to-one with the average slope of a long downhill section and is pre-stored in the calibration table of the thermal management controller. The greater the slope, the greater the regenerative braking power, the more intense the heat generation from the battery's internal resistance, and the lower the upper limit of the base temperature, leaving room for subsequent temperature rise. A 3% slope corresponds to an upper limit of the base temperature threshold set at 42℃, and a 6% slope corresponds to an upper limit of the base temperature threshold set at 38℃.

[0075] Based on the tunnel length, the length correction amount for the upper limit of the base temperature threshold is calculated using the following formula: ; in, This is the length correction amount; It is a negative constant; This is a preset reference tunnel length.

[0076] Specifically, the negative constant is in the same unit as the length correction. In one specific embodiment, the negative constant is set to -5°C.

[0077] Based on the upper limit of the basic temperature threshold and the length correction amount, the upper limit of the corrected preset operating temperature range is determined by the following formula: ; in, The upper limit of the preset operating temperature range; The upper limit of the base temperature threshold.

[0078] The lower limit of the preset operating temperature range is the preset minimum operating temperature.

[0079] Specifically, the lower limit of the preset operating temperature range is set as the preset minimum operating temperature to avoid excessive cooling that could affect battery activity. In one specific embodiment, the preset minimum operating temperature is set to 15°C.

[0080] Perform pre-scheduling operations for battery thermal management, including: Based on the end point of the downhill section and the start point of the tunnel section in the combined working condition, the combined working condition is divided into an entrance section, a middle section, and an exit section. The entrance section covers the area from the current vehicle position to the start point of the combined working condition; the middle section covers the area from the start point of the combined working condition to the end point of the tunnel section; and the exit section covers the area extending forward from the end point of the tunnel section by a second preset length.

[0081] Specifically, the present invention achieves pre-control in terms of timing through spatial decoupling: the entrance section is a defense preparation zone, the goal of which is to reduce the battery temperature to a safe baseline before entering the downhill section; the middle section is the core combat zone, where there is both downhill heat generation and tunnel heat dissipation deterioration, requiring high-frequency adaptive regulation; the exit section is a recovery buffer zone to prevent the cooling system from overcooling due to inertial operation after exiting the tunnel.

[0082] In one specific embodiment, the second preset length is set to 500 meters.

[0083] The system acquires the current temperature of the vehicle battery, the heat generated by regenerative braking, the direction signal of the vehicle's power battery bus current, and the upper limit of the preset operating temperature range. It then calculates the target temperature for the inlet section using the following formula: ; in, The target temperature for the inlet section; The upper limit of the preset operating temperature range; This is to pre-set a safety margin for the inlet section temperature.

[0084] Specifically, the preset inlet section temperature safety margin is set at 2℃.

[0085] When the distance between the vehicle and the starting point of the combined operating condition is greater than or equal to the preset pre-scheduling trigger distance, the battery thermal management system is controlled to adjust the battery temperature to the target temperature of the inlet segment. When the absolute value of the difference between the current temperature of the vehicle battery and the target temperature of the inlet segment is less than the preset convergence threshold, the pre-temperature adjustment is determined to be completed.

[0086] Specifically, after pre-temperature adjustment, it switches to low-power maintenance mode and waits to enter the mid-stage.

[0087] In one specific embodiment, the preset pre-scheduling trigger distance is set to 800 meters; the preset convergence threshold is set to 1°C.

[0088] When the vehicle enters the middle section, based on the current temperature of the vehicle battery, the heat generated by braking regeneration and the heat dissipation reduction coefficient, the battery temperature of the next cycle is predicted according to the control cycle. Based on the comparison between the battery temperature of the next cycle and the upper limit of the preset operating temperature range and the lower limit of the preset operating temperature range, the cooling power of the battery thermal management system is adaptively controlled.

[0089] Specifically, the formula for calculating the battery temperature in the next cycle is: ; in, The battery temperature for the next cycle; To control the cycle duration.

[0090] Based on the comparison between the battery temperature of the next cycle and the upper and lower limits of the preset operating temperature range, the cooling power of the battery thermal management system is adaptively controlled, including: When the current direction signal of the power battery bus is charging and the regenerative braking power is greater than the preset regenerative braking power threshold, it is determined to be an energy recovery working condition.

[0091] The formula for calculating the regenerative braking power is: ; in, To recover electrical power for braking.

[0092] In one specific embodiment, the preset recoverable power threshold is set to 5kW.

[0093] The battery temperature for the next cycle is compared with the upper limit and lower limit of the preset operating temperature range.

[0094] If the battery temperature in the next cycle exceeds the upper limit of the preset operating temperature range, the cooling power of the battery thermal management system will be increased. The formula for calculating the increase in cooling power is as follows: ; in, This represents the increase in cooling power. This is the preset proportional control coefficient; The upper limit of the preset operating temperature range.

[0095] Specifically, if the battery temperature in the next cycle exceeds the upper limit of the preset operating temperature range, it is determined that the limit is about to be exceeded, and the cooling power is increased. In one specific embodiment, the preset proportional control coefficient is set to 2 kW / ℃.

[0096] If the battery temperature in the next cycle is lower than the lower limit of the preset operating temperature range, and the condition is determined to be energy recovery mode, then the cooling power of the battery thermal management system will be reduced. The reduction in cooling power will be: ; in, This represents the reduction in cooling power. The preset power relaxation factor; The lower limit of the preset operating temperature range is set; if the cooling power is reduced to zero and still does not meet the heating requirements, the heating function will be activated.

[0097] Specifically, the energy recovery condition indicates excessive cooling at the end of a long downhill section or in extremely cold environments, requiring a reduction in cooling power. In one specific embodiment, the preset power relaxation factor is set to 0.2 kW / ℃.

[0098] If the battery temperature in the next cycle is lower than the lower limit of the preset operating temperature range and is not determined to be in an energy recovery condition, the current cooling power will be maintained to avoid unnecessary energy consumption adjustments.

[0099] If the battery temperature in the next cycle is greater than or equal to the lower limit of the preset operating temperature range, but less than or equal to the upper limit of the preset operating temperature range, then the current cooling power will remain unchanged.

[0100] When the vehicle enters the exit section, the battery thermal management system is controlled to cool to the target temperature of the exit section. The calculation formula is as follows: ; in, The target temperature for the outlet section; This is the preset temperature buffer amount for the outlet section.

[0101] Specifically, as the vehicle exits the tunnel and enters the exit section, environmental heat dissipation conditions return to normal, but the battery itself still has a high heat capacity. The battery thermal management system is controlled to cool the vehicle to the target temperature at the exit section. Since the airflow naturally enhances heat dissipation after exiting the tunnel, a larger buffer capacity can prevent the cooling system from overworking and causing overcooling shock, thus achieving a soft landing for the thermal management system.

[0102] In one specific embodiment, the preset outlet section temperature buffer is set to 5°C.

[0103] like Figure 2 As shown, another embodiment of the present invention provides a V2X-based battery temperature control system for electric vehicles under combined operating conditions. The system includes an information acquisition module, a combined operating condition identification module, a battery temperature prediction module, and a thermal management pre-scheduling module.

[0104] The information acquisition module is used to acquire the current temperature and state of charge of the vehicle battery, and to acquire road information within a first preset distance ahead of the vehicle through V2X communication.

[0105] The combined working condition recognition module is used to identify, based on road information, whether there is a combined working condition in front of the vehicle consisting of a downhill section and a tunnel section.

[0106] The battery temperature prediction module is used to predict the expected temperature change of the vehicle's battery during the duration of the combined operating conditions, based on the current temperature of the vehicle's battery, state of charge, and road information.

[0107] The thermal management pre-scheduling module is used to perform thermal management pre-scheduling operations on the battery when the vehicle travels to the starting position of the combined operating conditions and reaches the preset pre-scheduling trigger distance, based on the expected temperature change and the preset operating temperature range. The preset operating temperature range is dynamically determined based on road information and includes the upper temperature limit and the lower temperature limit of the preset operating temperature range.

[0108] In summary, this invention proposes a V2X-based battery temperature control method and system for electric vehicles operating under combined conditions. Addressing the control lag and blind spots caused by traditional thermal management relying solely on local sensor feedback, this invention first breaks down information silos by utilizing V2X communication to proactively perceive the geometric features and environmental conditions of long downhill slopes and tunnels ahead, accurately identifying combined operating conditions that are closely connected and prone to heat accumulation and thermal shock risks. Second, overcoming the limitations of conventional single-condition modeling, it constructs a refined net heat generation prediction model that integrates the downhill braking regeneration heat generation mechanism and the tunnel heat dissipation reduction effect, enabling accurate forward-looking prediction of the expected battery temperature rise throughout the combined operating conditions. Finally, it pioneers a spatiotemporally decoupled three-stage active pre-scheduling strategy. Constrained by a dynamic safety zone, it performs pre-cooling to reserve thermal safety margin at the entrance stage, adaptive closed-loop control based on the predicted temperature of the next cycle in the middle stage, and achieves a smooth soft landing of the thermal management system at the exit stage. This invention deeply couples prior road information with underlying thermal control, fundamentally resolving the contradiction between uncontrolled battery temperature rise and overcooling under combined operating conditions. While ensuring absolute battery safety, it maximizes the heat generation power of regenerative braking and reduces the additional energy consumption of the thermal management system.

[0109] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for battery temperature control under combined operating conditions of electric vehicles based on V2X, characterized in that, include: The vehicle battery's current temperature and state of charge are obtained, and road information within a first preset distance ahead of the vehicle is obtained via V2X communication. Based on road information, identify whether there is a combination of road conditions consisting of downhill sections and tunnel sections ahead of the vehicle; When a combined operating condition is identified, the expected temperature change of the vehicle's battery during the duration of the combined operating condition is predicted based on the vehicle's current battery temperature, state of charge, and road information. When the vehicle travels to the starting position of the combined operating condition and reaches the preset pre-scheduling trigger distance, the battery performs a thermal management pre-scheduling operation based on the expected temperature change and the preset operating temperature range; the preset operating temperature range is dynamically determined based on road information and includes the upper temperature limit and the lower temperature limit of the preset operating temperature range.

2. The method for battery temperature control under combined operating conditions of electric vehicles based on V2X according to claim 1, characterized in that, The method of obtaining road information within a first preset distance ahead of the vehicle through V2X communication includes the slope distribution curve and slope length information of long downhill road sections, the tunnel length and ventilation information of tunnel sections, as well as the curvature radius and traffic flow density information of the road.

3. The battery temperature control method for electric vehicle combination operating conditions based on V2X according to claim 1, characterized in that, The identification of whether there is a combination of road conditions consisting of a downhill section and a tunnel section ahead of the vehicle includes: Determine whether the distance between the toe of the downhill section and the entrance of the tunnel section is less than a second preset distance threshold; When the distance is less than the second preset distance threshold, the long downhill section and the tunnel section are determined to form a combined working condition, and the starting position of the downhill section is defined as the starting position of the combined working condition.

4. The battery temperature control method for V2X-based electric vehicle combined operating conditions according to claim 1, characterized in that, The prediction of the expected temperature change of the battery during the duration of combined operating conditions includes: Obtain the initial time when the vehicle enters the combined operating condition and the expected termination time when it exits the combined operating condition; calculate the cumulative net heat generation of the vehicle under the combined operating condition using the following formula: ； in, To accumulate net heat production; This refers to the initial moment when the vehicle enters the combined operating condition. The termination time of exiting the combined operating condition; For the battery Net heat output at any given moment; Based on the cumulative net heat generation, battery mass, and battery specific heat capacity, the temperature change of the battery under combined operating conditions is calculated using the following formula: ； in, This refers to the change in temperature. To accumulate net heat production; For the quality of the battery; This refers to the specific heat capacity of the battery. Based on the temperature change and the current battery temperature, the expected maximum temperature of the battery is predicted.

5. The battery temperature control method for V2X-based electric vehicle combined operating conditions according to claim 4, characterized in that, The calculation of the net heat power output includes: Based on downhill road parameters, the regenerative braking heat generation power of the vehicle on the downhill section is obtained, and the basic heat dissipation power of the battery is obtained based on the current vehicle speed; based on the tunnel length and ambient wind speed in the tunnel section parameters, the heat dissipation reduction factor of the vehicle in the tunnel section is calculated, and the calculation formula is as follows: ； in, This is the heat dissipation reduction factor; The preset maximum heat dissipation attenuation ratio; The length of the tunnel; Preset reference tunnel length; is the base of the natural logarithm; Wind speed inside the tunnel; The preset reference wind speed is used; based on the regenerative braking heat generation power, the basic heat dissipation power, and the heat dissipation reduction factor, the battery's performance is calculated. The net heat output at any given time is calculated using the following formula: ； in, Net heat output; To recover the heat generated by braking; This is the heat dissipation reduction factor; Based on the heat dissipation power.

6. The battery temperature control method for V2X-based electric vehicle combined operating conditions according to claim 5, characterized in that, The method of obtaining the regenerative braking heat generation power of a vehicle on a downhill section based on downhill road parameters includes: Based on the current absolute slope angle, current vehicle speed, and vehicle mass, calculate the downhill driving power provided by gravity along the slope direction. The calculation formula is as follows: ； in, This is the downhill drive power; For the overall vehicle weight; It is the acceleration due to gravity; Current vehicle speed; This is the absolute angle value of the slope; Based on the downhill driving power and the driving resistance power required to maintain the current vehicle speed, the regenerative braking power is determined using the following formula: ； in, Recoverable braking power; Power is the driving resistance. Based on the recyclable braking power, the motor's power generation efficiency, the battery's internal charging resistance, and the battery's current voltage, the braking heat recovery power is calculated using the following formula: ; in, To recover the heat generated by braking; The power generation efficiency of the motor; This is the current battery voltage. The internal resistance of the battery during charging; To recover electrical power for braking; The process of obtaining the battery's basic heat dissipation power based on the current vehicle speed includes: obtaining the current battery temperature, ambient temperature, and current vehicle speed; and calculating the equivalent convective heat transfer coefficient of the battery casing surface based on the current vehicle speed, using the following formula: ； in, It is the equivalent convective heat transfer coefficient; The coefficient of heat transfer is the natural convection heat transfer coefficient. This is the wind speed enhancement coefficient; Based on the equivalent convective heat transfer coefficient, the current battery temperature, and the ambient temperature, the basic heat dissipation power is calculated using the following formula: ； in, Basic heat dissipation power; The equivalent area for convective heat transfer between the battery and the air; This refers to the current temperature of the battery. The ambient temperature.

7. The battery temperature control method for electric vehicle combination operating conditions based on V2X according to claim 1, characterized in that, The preset operating temperature range is dynamically determined based on road information, including: Based on the slope value of the long downhill section, determine the upper limit of the basic temperature threshold corresponding to the slope value; based on the tunnel length, calculate the length correction amount for the upper limit of the basic temperature threshold, using the following formula: ； in, This is the length correction amount; It is a negative constant; The preset reference tunnel length is used as a reference. Based on the upper limit of the basic temperature threshold and the length correction amount, the upper limit of the corrected preset operating temperature range is determined using the following formula: ； in, The upper limit of the preset operating temperature range; The upper limit of the base temperature threshold; The lower limit of the preset operating temperature range is the preset minimum operating temperature.

8. The battery temperature control method for V2X-based electric vehicle combined operating conditions according to claim 6, characterized in that, The pre-scheduling operation for thermal management of the battery includes: Based on the end point of the downhill section and the start point of the tunnel section in the combined working condition, the combined working condition is divided into an entrance section, a middle section, and an exit section. The entrance section covers the area from the current vehicle position to the start point of the combined working condition. The middle section covers the area from the start point of the combined working condition to the end point of the tunnel section. The exit section covers the area extending forward from the end point of the tunnel section by a second preset length. The system acquires the current temperature of the vehicle battery, the heat generated by regenerative braking, the direction signal of the vehicle's power battery bus current, and the upper limit of the preset operating temperature range. It then calculates the target temperature for the inlet section using the following formula: ； in, The target temperature for the inlet section; The upper limit of the preset operating temperature range; This is to allow for a safety margin in the inlet section temperature. When the distance between the vehicle and the starting point of the combined operating condition is greater than or equal to the preset pre-scheduling trigger distance, the battery thermal management system is controlled to adjust the battery temperature to the target temperature of the inlet section. When the absolute value of the difference between the current temperature of the vehicle battery and the target temperature of the inlet section is less than the preset convergence threshold, the pre-temperature adjustment is determined to be completed. When the vehicle enters the middle section, based on the current temperature of the vehicle battery, the heat generated by regenerative braking and the heat dissipation reduction coefficient, the battery temperature of the next cycle is predicted according to the control cycle. Based on the comparison between the battery temperature of the next cycle and the upper limit of the preset operating temperature range and the lower limit of the preset operating temperature range, the cooling power of the battery thermal management system is adaptively controlled. When the vehicle enters the exit section, the battery thermal management system is controlled to cool to the target temperature of the exit section. The calculation formula is as follows: ； in, The target temperature for the outlet section; This is the preset temperature buffer amount for the outlet section.

9. The method for battery temperature control under combined operating conditions of an electric vehicle based on V2X as described in claim 8, characterized in that, The adaptive control of the cooling power of the battery thermal management system based on the comparison results between the battery temperature of the next cycle and the upper and lower limits of the preset operating temperature range includes: When the power battery bus current direction signal indicates charging, and the regenerative braking power exceeds a preset regenerative braking power threshold, the system is determined to be in energy recovery mode. The battery temperature for the next cycle is compared with the upper and lower limits of the preset operating temperature range. The formula for calculating the battery temperature for the next cycle is as follows: ； in, The battery temperature for the next cycle; To control cycle duration, if the battery temperature in the next cycle exceeds the upper limit of the preset operating temperature range, the cooling power of the battery thermal management system will be increased. The formula for calculating the increase in cooling power is as follows: ； in, This represents the increase in cooling power. This is the preset proportional control coefficient; The upper limit of the preset operating temperature range is set. If the battery temperature in the next cycle is lower than the lower limit of the preset operating temperature range, and the condition is determined to be energy recovery mode, the cooling power of the battery thermal management system will be reduced. The reduction in cooling power is as follows: ； in, This represents the reduction in cooling power. The preset power relaxation factor; The lower limit of the preset operating temperature range; if the cooling power is reduced to zero and still cannot meet the heating requirement, the heating function will be activated. If the battery temperature in the next cycle is lower than the lower limit of the preset operating temperature range and is not determined to be an energy recovery condition, the current cooling power will remain unchanged. If the battery temperature in the next cycle is greater than or equal to the lower limit of the preset operating temperature range, but less than or equal to the upper limit of the preset operating temperature range, then the current cooling power will remain unchanged.

10. A V2X-based battery temperature control system for electric vehicle combination operating conditions, based on the V2X-based battery temperature control method for electric vehicle combination operating conditions according to any one of claims 1 to 9, characterized in that, include: The information acquisition module is used to acquire the current temperature and state of charge of the vehicle battery, and to acquire road information within a first preset distance in front of the vehicle through V2X communication; The combined working condition recognition module is used to identify, based on road information, whether there is a combined working condition in front of the vehicle consisting of a downhill section and a tunnel section; The battery temperature prediction module is used to predict the expected temperature change of the vehicle's battery during the duration of the combined operating conditions based on the current temperature of the vehicle's battery, state of charge, and road information when a combined operating condition is identified. The thermal management pre-scheduling module is used to perform thermal management pre-scheduling operations on the battery based on the expected temperature change and the preset operating temperature range when the vehicle travels to the starting position of the combined operating conditions and reaches the preset pre-scheduling trigger distance. The preset operating temperature range is dynamically determined based on road information and includes the upper temperature limit and the lower temperature limit of the preset operating temperature range.

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