A Battery Temperature Control Method and System Based on New Energy Vehicles

Abstract

The present invention relates to the technical field of battery temperature control, and specifically discloses a battery temperature control method and system based on new energy vehicles. The method includes the following steps: S1: Determine different working conditions based on preset power nodes and duration nodes; construct a three-dimensional space model of the battery, determine reference point acquisition points, and determine the isotherms of the temperature of the battery when operating under different working conditions; S2: Determine projection points, connect the projection points on the surface of the three-dimensional space model to obtain projection lines; group the projection lines and determine representative lines, sort the representative lines to obtain a first sorting; determine the target sorting position in the first sorting, and determine the target line among the representative lines; S3: Determine a target range according to the representative line, and control the average temperature within the target range to be within the temperature range. The present invention can avoid the problem of local overheating / cooling during the operation of the battery and improve the safety of new energy vehicles.

Description

Technical Field

[0001] The present invention relates to the technical field of battery temperature control, and in particular to a battery temperature control method and system based on new energy vehicles. Background Art

[0002] With the continuous advancement of science and technology and the increasing awareness of environmental protection, the new energy vehicle industry has ushered in unprecedented development opportunities. As one of the core components of new energy vehicles, the performance of batteries directly affects the safety of new energy vehicles.

[0003] Batteries generate heat due to charging and discharging during operation, and the performance, life and safety of the battery are closely related to its operating temperature. Excessively high temperatures will accelerate battery performance degradation and increase the risk of thermal runaway; excessively low temperatures will reduce the battery's available capacity and discharge capacity, affecting the vehicle's endurance and charging efficiency.

[0004] Conventional battery temperature control methods, such as liquid cooling control, intelligently adjust the temperature through the coolant flow rate control system (pump speed and valve) according to the battery temperature changes. When the battery temperature is too high, the coolant flow rate is increased; when the temperature is close to the normal range, the pump speed is reduced to save energy, thereby ensuring that the battery temperature is within an appropriate range. However, in actual use, the temperature of different parts of the battery may also be different. In this case, increasing the coolant flow rate may cause the battery temperature at a certain position to be too low, or reducing the coolant flow rate may cause the battery temperature at a certain position to be too high. Summary of the invention

[0005] The purpose of the present invention is to provide a battery temperature control method and system based on new energy vehicles to solve the following technical problems:

[0006] The temperature of different parts of the battery may be different. In this case, increasing the coolant flow rate may cause the battery temperature at a certain position to be too low, or reducing the coolant flow rate may cause the battery temperature at a certain position to be too high.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A battery temperature control method based on a new energy vehicle comprises the following steps:

[0009] S1: Set a number of power nodes and duration nodes in the preset output power interval and battery single working time interval, and determine N different working conditions. Different working conditions correspond to different power nodes and / or duration nodes. The target number , n1 and n2 represent the total number of power nodes and duration nodes respectively;

[0010] Construct a three-dimensional space model of the battery, set a number of acquisition points at a preset distance interval in the three-dimensional space model. After the battery operates under the a-th working condition, obtain the temperature at the acquisition points, and draw the isotherm of the temperature;

[0011] S2: Determine the projection point of any point on the isotherm on the reference plane. The reference plane is the plane in the three-dimensional space model that is closest to the point on the isotherm. Connect the projection points on the surface of the three-dimensional space model to obtain the projection line;

[0012] Group the projection lines. The similarity degree between any two projection lines in the group is greater than the preset similarity degree threshold P. Execute the preset screening step to determine the representative line in the group, and sort the representative lines in descending order according to the judgment quantity. The judgment quantity represents the total number of projection lines in the group corresponding to the representative line;

[0013] Determine the target sorting position m in the first sorting. The target sorting position m satisfies the constraint: and , represents the total length of the first m representative lines in the first sorting, Lys represents the preset total length threshold, and use the representative lines at the first m sorting positions in the first sorting as the target lines;

[0014] S3: Take the point A on the target line as the center of the circle, and make a circle with a radius of the preset value R as the target circle. The target circle is within the target plane, and the target plane is the plane in the three-dimensional space model where the point A is located. Merge the target circles to obtain the target range;

[0015] Install a cooling pipe along the target line on the battery surface, obtain the average temperature within the target range in real time, and control the flow rate of the coolant in the cooling pipe based on the PID control algorithm to ensure that the average temperature within the target range is within the preset temperature range.

[0016] As a further solution of the present invention: In the step S2, when the total length of all the representative curves in the first sorting is less than the total length threshold, execute the following steps:

[0017] Step 1: Let the similarity degree threshold , and re-group the projection lines, and determine the total length of all the representative curves in the first sorting again, represents the preset similarity degree threshold adjustment value;

[0018] When the total length of all the representative curves in the new first sorting is less than the total length threshold, repeat the above steps;

[0019] Step 2: When the similarity threshold P≥Pmax, if the total length of all representative curves in the corresponding first sorting is still less than the total length threshold, repeat steps S1-S2 to obtain projection lines again, and group the projection lines again, and repeat step 1, where Pmax represents the preset maximum similarity value, until the total length of all representative curves in the first sorting is greater than or equal to the total length threshold.

[0020] As a further solution of the present invention: in the step S3, when the flow rate of the coolant reaches the maximum flow rate, the average temperature within the target range is still rising, and an early warning message is sent for prompting.

[0021] As a further solution of the present invention: in step S2, the process of determining the similarity of the projection lines specifically includes:

[0022] A coordinate system is established with the preset position as the origin, the functional relationship of the projection line is determined, and the similarity of the projection line is determined based on the Fréchet distance.

[0023] As a further solution of the present invention: in the step S2, in the process of obtaining the first sorting, when two or more judgment numbers are the same, the representative lines corresponding to the group with a larger total length of projection lines are ranked higher.

[0024] As a further solution of the present invention: in the step S2, when the distances between the point c on the contour line C and two or more planes in the three-dimensional space model are the same and are the minimum, the following steps are performed:

[0025] The plane with the same minimum distance from the three-dimensional space model to point c is taken as the undetermined plane, the proportion of the projection point corresponding to the contour line C in the undetermined plane is determined, and the undetermined plane corresponding to the maximum proportion is taken as the reference plane of point c.

[0026] As a further solution of the present invention: in the step S3, when the point A is on the intersection line B of two planes in the three-dimensional space model, a line segment with a length of R and a midpoint A is determined on the intersection line B, and it is used as the target circle corresponding to point A.

[0027] As a further solution of the present invention: in the step S2, the process of determining the representative line specifically includes:

[0028] The projection line in the group is taken as the pending line, the pending line X is taken as the reference line, the total similarity PZ between the reference line and the pending line is determined, and the pending line corresponding to the maximum total similarity is taken as the representative line.

[0029] A battery temperature control system based on new energy vehicles, comprising:

[0030] Acquisition module: Set a number of power nodes and duration nodes at preset output power intervals and battery single - working - duration intervals with preset output power intervals and battery single - working - duration intervals respectively, determine N different working conditions, where the power nodes and / or duration nodes corresponding to different working conditions are different, and the target quantity , where n1 and n2 respectively represent the total numbers of the power nodes and duration nodes described above;

[0031] Construct a three - dimensional space model of the battery, set a number of acquisition points at a preset distance interval in the three - dimensional space model. After the battery operates in the a - th working condition, obtain the temperatures at the acquisition points and draw the isothermal lines of the temperature;

[0032] Analysis module: Determine the projection points of any point on the isothermal line on the reference plane, where the reference plane is the plane in the three - dimensional space model that is closest to the point on the isothermal line. Connect the projection points on the surface of the three - dimensional space model to obtain projection lines;

[0033] Group the projection lines. The similarity degree between any two projection lines in the group is greater than a preset similarity degree threshold P. Execute a preset screening step to determine the representative line in the group, and sort the representative lines in descending order according to the judgment quantity, where the judgment quantity represents the total number of projection lines in the group corresponding to the representative line;

[0034] Determine the target sorting position m in the first sorting, where the target sorting position m satisfies the constraint: And , , where represents the total length of the first m representative lines in the first sorting, Lys represents a preset total length threshold, and take the representative lines at the first m sorting positions in the first sorting as the target lines;

[0035] Control module: Take point A on the target line as the center and make a circle with a radius of a preset value R as the target circle. The target circle is within the target plane, and the target plane is the plane in the three - dimensional space model where point A is located. Merge the target circles to obtain the target range;

[0036] Install cooling pipes along the target line on the battery surface, obtain the average temperature within the target range in real - time, and control the flow rate of the coolant in the cooling pipes based on the PID control algorithm to ensure that the average temperature within the target range is within a preset temperature range.

[0037] Advantages of the present invention: In this solution, within a preset output power range and working duration range, several power nodes and duration nodes are selected at certain intervals to construct multiple different working conditions. These working conditions cover various working conditions that the battery may encounter during actual use. Therefore, during the simulation stage, the temperature distribution characteristics of the battery can be comprehensively observed through multiple sets of data, ensuring that it is not limited to the results of a single working condition. By constructing a three-dimensional model of the battery and setting acquisition points therein to obtain temperature information, temperature isotherms can be obtained, which can better understand the spatial distribution of temperatures in different regions and provide basic data and references for subsequent analysis, enabling the control strategy to be formulated based on more sufficient and realistic working condition data and improving the adaptability of the solution to the actual use scenario; afterwards, the projections of any point on the isotherm on the reference plane are connected to obtain a projection line; it should be noted that the reference plane is closest to the internal high-temperature region in space, and the corresponding projection line represents the shortest heat transfer path from the internal hot spot to the external surface. Laying cooling pipes on the outside guided by this projection line can effectively improve the pertinence and efficiency of the cooling measures, allowing the cooling medium to act on the outside of the region that most needs cooling, so as to quickly remove the excessive internal heat along the shortest heat transfer path; then, representative lines are selected through grouping and similarity determination, and sorted and the target line is determined according to the length characteristics of these representative lines, so as to select representative lines from numerous possible temperature characteristic curves, enabling the control strategy to be designed not by dealing with all complex curves in a comprehensive manner, but by focusing on the most representative and influential curves. This process of screening and extracting representatives helps to determine a more reasonable layout direction and area of the cooling pipes, thereby achieving higher precision and efficiency during the implementation of the control strategy; finally, a circle with a certain radius is drawn with a specific point on the target line as the center, and the target range is obtained through combination, so as to precisely control the temperature of specific key areas on the battery surface. The cooling pipes are installed near the target line, and the flow rate of the coolant is dynamically adjusted through the PID control algorithm to ensure that the average temperature within this target range is maintained within the preset ideal temperature range. The advantage of this local precise control method of using a point to drive the surface is that, with the accurate target area and representative characteristic lines provided by the previous two steps, differential cooling deployment can be achieved, making the cooling measures more targeted. When the target area is approximately isothermal and reasonably demarcated, the PID control's adjustment of the fluid flow rate will be more sensitive and efficient, thereby reducing the possibility of local deviation. The present invention can maintain the temperature field as evenly as possible within a reasonable range during the actual operation of the battery, effectively reducing the probability of local overheating or overcooling of the battery during operation and improving the safety and performance of the battery. Description of the Drawings

[0038] The present invention will be further described below with reference to the drawings.

[0039] Figure 1 It is a schematic flow chart of a battery temperature control method for a new energy vehicle according to the present invention. Specific embodiments

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0041] Please refer to Figure 1 As shown, the present invention is a battery temperature control method for a new energy vehicle, including the following steps:

[0042] S1: Set a number of power nodes and duration nodes at preset output power intervals and battery single - working - duration intervals respectively with preset output power intervals and battery single - working - duration intervals, determine N different working conditions, where different working conditions correspond to different power nodes and / or duration nodes, and the target quantity , where n1 and n2 respectively represent the total numbers of the power nodes and duration nodes described above.

[0043] Construct a three - dimensional space model of the battery, set a number of acquisition points at a preset distance interval in the three - dimensional space model. After the battery operates under the a - th working condition, obtain the temperatures at the acquisition points and draw the isotherms of the temperatures.

[0044] S2: Determine the projection point of any point on the isotherm on the reference plane, where the reference plane is the plane in the three - dimensional space model that is closest to the point on the isotherm. Connect the projection points on the surface of the three - dimensional space model to obtain a projection line.

[0045] Group the projection lines. The similarity degree between any two projection lines in the group is greater than a preset similarity degree threshold P. Execute a preset screening step to determine the representative line in the group, and sort the representative lines in descending order according to the size of the judgment quantity, where the judgment quantity represents the total number of projection lines in the group corresponding to the representative line.

[0046] Determine the target sorting position m in the first sorting, where the target sorting position m satisfies the constraint: and , represents the total length of the first m representative lines in the first sorting, Lys represents a preset total length threshold, and use the representative lines at the first m sorting positions in the first sorting as the target lines.

[0047] S3: Taking point A on the target line as the center, draw a circle with a radius of the preset value R as the target circle. The target circle is within the target plane, and the target plane is the plane where point A is located in the three-dimensional space model. Merge the target circles to obtain the target range;

[0048] Install a cooling pipe along the target line on the battery surface, and obtain the average temperature within the target range in real time. Control the flow rate of the coolant in the cooling pipe based on the PID control algorithm to ensure that the average temperature within the target range is within the preset temperature range.

[0049] It should be noted that by selecting a number of power nodes and duration nodes at certain intervals within a preset output power range and working duration range, multiple different working conditions are constructed. These working conditions cover various working conditions that the battery may encounter during actual use, so that the temperature distribution characteristics of the battery can be comprehensively observed through multiple sets of data during the simulation stage, ensuring that it is not limited to the results of a single working condition. By constructing a three-dimensional model of the battery and setting acquisition points therein to obtain temperature information, temperature isotherms can be obtained, which can better understand the spatial distribution of temperatures in different regions, provide basic data and references for subsequent analysis, and enable the control strategy to be formulated based on more sufficient and realistic working condition data, improving the adaptability of the solution to the actual use scenario; thereafter, the projections of any point on the isotherm on the reference plane are connected to obtain a projection line; it should be noted that the reference plane is the closest to the internal high-temperature region in space, and the corresponding projection line represents the shortest heat transfer path from the internal hot spot to the external surface. Laying cooling pipes on the outside guided by this projection line can effectively improve the pertinence and efficiency of the cooling measures, allowing the cooling medium to act outside the region that most needs cooling, so as to quickly remove the excessive internal heat along the shortest heat transfer path; then, representative lines are selected through grouping and similarity determination, and sorted and the target line is determined according to the length characteristics of these representative lines, so as to select representative lines from among many possible temperature characteristic curves, such that instead of dealing with all complex curves in a comprehensive manner, the control strategy design focuses on the most representative and influential curves. This process of screening and extracting representatives helps to determine a more reasonable layout direction and area for the cooling pipes, thereby achieving higher precision and efficiency during the execution of the control strategy; finally, a circle with a certain radius is drawn with a specific point on the target line as the center, and the target range is obtained through combination, so as to perform precise cooling control on a specific key area on the battery surface. The cooling pipes are installed near the target line, and the flow rate of the coolant is dynamically adjusted through the PID control algorithm to ensure that the average temperature within this target range is maintained within a preset ideal temperature range. The advantage of this local precise control method that uses points to drive the surface is that, with the help of the accurate target area and representative characteristic lines provided by the previous two steps, differential cooling deployment can be achieved, making the cooling measures more targeted. When the target area is approximately isothermal and reasonably demarcated, the PID control's adjustment of the fluid flow rate will be more sensitive and efficient, thereby reducing the possibility of local deviation.

[0050] In another preferred embodiment of the present invention, in step S2, when the total length of all representative curves in the first sorting is less than the total length threshold, the following steps are executed:

[0051] Step 1: Let the similarity threshold , and regroup the projection lines again, and determine the total length of all the representative curves in the first sorting again. represents a preset similarity degree threshold adjustment value;

[0052] When the total length of all the representative curves in the new first sorting is less than the total length threshold, repeat the above steps;

[0053] Step 2: When the similarity degree threshold P ≥ Pmax, if the total length of all the representative curves in the corresponding first sorting is still less than the total length threshold, repeat steps S1 - S2 to obtain projection lines again, and regroup the projection lines again, and repeat Step 1. Pmax represents a preset maximum similarity degree. This is done until the total length of all the representative curves in the first sorting is greater than or equal to the total length threshold.

[0054] It can be understood that by dynamically adjusting the similarity degree threshold P and repeating steps S1 - S2 when necessary, it is ensured that the finally selected set of representative curves (i.e., the representative curves in the first sorting) can meet the requirements of the preset total length threshold. When the total length of all the representative curves obtained under the original similarity degree threshold is still insufficient to meet the total length threshold, the similarity degree threshold P will be increased by a preset increment , so as to classify and group the projection lines more broadly or more strictly (specifically depending on the change in the classification result brought about by the increase in P), and then re - determine the total length of all the representative curves in the first sorting. Through this iterative method, different similarity degree grouping criteria are continuously tried, aiming to obtain more or more suitable representative curves (while ensuring the similarity between the curves, the sum of the lengths of the representative curves can reach the target standard). If, after gradually increasing P until reaching Pmax (the preset upper limit of the maximum similarity degree threshold), the total length threshold requirement is still not met, then it will go back to the previous link, repeat steps S1 - S2 to obtain new projection line data, regroup and select again until the total length threshold is reached. Through such adaptive adjustment and loop, the method can flexibly optimize the selection process of the representative curves under different conditions, ensuring that the final set of representative curves has sufficient reference value and robustness for the subsequent determination and execution of the cooling strategy.

[0055] In another preferred embodiment of the present invention, in step S3, when the flow rate of the coolant reaches the maximum flow rate and the average temperature within the target range is still rising, a warning message is sent for prompt.

[0056] In another preferred embodiment of the present invention, in step S2, the process of determining the similarity degree of the projection lines specifically includes:

[0057] Establish a coordinate system with a preset position as the origin, determine the functional relationship of the projection line described above, and determine the similarity degree of the projection line based on the Fréchet distance.

[0058] It should be noted that the Fréchet distance is a geometric index used to measure the similarity between two curves (or paths). Different from the general point-to-point distance measurement, the Fréchet distance not only considers the spatial distance relationship between points on the curves, but also considers the order and matching method of the two curves advancing along their respective parameter directions.

[0059] In another preferred embodiment of the present invention, in step S2, during the process of obtaining the first ranking, when the judgment quantities of two or more are the same, the group corresponding to the projection line with a greater total length has a more forward ranking for the representative line.

[0060] In another preferred embodiment of the present invention, in step S2, when the distance from a point c on the isoline C to two or more planes in the three-dimensional space model is the same and is the minimum value, the following steps are executed:

[0061] Use the plane in the three-dimensional space model with the same and minimum distance from point c as the plane to be determined, determine the proportion of the projection point corresponding to the isoline C in the plane to be determined, and use the plane to be determined corresponding to the maximum proportion as the reference plane of point c

[0062] In another preferred embodiment of the present invention, in step S3, when point A is on the intersection line B of two planes in the three-dimensional space model, then determine a line segment with a length of R and the midpoint being A on the intersection line B, and use it as the target circle corresponding to point A.

[0063] In another preferred embodiment of the present invention, in step S2, the process of determining the representative line specifically includes:

[0064] Use the projection lines in the group as the lines to be determined, use the line to be determined X as the reference line, determine the total similarity degree PZ between the reference line and the lines to be determined, and use the line to be determined corresponding to the maximum total similarity degree as the representative line.

[0065] A battery temperature control system based on a new energy vehicle, comprising:

[0066] Acquisition module: Set a number of power nodes and duration nodes at preset output power intervals and battery single working duration intervals respectively with preset output power intervals and battery single working duration intervals, determine N different working conditions, and different working conditions correspond to different power nodes and / or duration nodes, the target quantity , where n1 and n2 respectively represent the total numbers of the power nodes and duration nodes described above;

[0067] Construct a three-dimensional space model of the battery, set a number of acquisition points at a preset distance interval in the three-dimensional space model. After the battery operates under the a-th working condition, obtain the temperature at the acquisition points and draw the isotherm of the temperature.

[0068] Analysis module: Determine the projection point of any point on the isotherm on the reference plane. The reference plane is the plane in the three-dimensional space model that is closest to the point on the isotherm. Connect the projection points on the surface of the three-dimensional space model to obtain a projection line.

[0069] Group the projection lines. The similarity degree between any two projection lines in the group is greater than the preset similarity degree threshold P. Execute the preset screening step to determine the representative line in the group. Sort the representative lines in descending order according to the judgment quantity. The judgment quantity represents the total number of projection lines in the group corresponding to the representative line.

[0070] Determine the target sorting position m in the first sorting. The target sorting position m satisfies the constraint: And , represents the total length of the first m representative lines in the first sorting, Lys represents the preset total length threshold. Take the representative lines at the first m sorting positions in the first sorting as the target lines.

[0071] Control module: Take point A on the target line as the center and make a circle with a radius of the preset value R as the target circle. The target circle is within the target plane, and the target plane is the plane in the three-dimensional space model where point A is located. Merge the target circles to obtain the target range.

[0072] Install cooling pipes along the target line on the battery surface. Real-time obtain the average temperature within the target range. Control the flow rate of the coolant in the cooling pipes based on the PID control algorithm to ensure that the average temperature within the target range is within the preset temperature range.

[0073] The above has described a specific embodiment of the present invention in detail, but the content is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A battery temperature control method based on new energy vehicles, characterized in that: The following steps are involved: S1: Set a number of power nodes and duration nodes in the preset output power interval and battery single working time interval, and determine N different working conditions. Different working conditions correspond to different power nodes and / or duration nodes. The target number , n1 and n2 represent the total number of power nodes and duration nodes respectively; Constructing a three-dimensional space model of the battery, setting a plurality of collection points at preset distance intervals in the three-dimensional space model, obtaining the temperature at the collection points after the battery is operated in the ath working condition, and drawing temperature contour lines; S2: Determine the projection point of any point on the contour line on the reference surface, the reference surface being the surface in the three-dimensional space model that is closest to the point on the contour line, and connect the projection points on the surface of the three-dimensional space model to obtain a projection line; The projection lines are grouped, and the similarity between any two projection lines in the group is greater than a preset similarity threshold value P, a preset screening step is performed to determine a representative line in the group, and the representative lines are sorted in descending order according to the size of the judgment quantity to obtain a first sort, where the judgment quantity represents the total number of projection lines in the group corresponding to the representative line; Determine a target sorting position m in the first sorting, wherein the target sorting position m satisfies the constraint: and , represents the total length of the first m representative lines in the first sorting, Lys represents a preset total length threshold, and the representative lines at the first m sorting positions in the first sorting are taken as target lines; S3: With point A on the target line as the center, draw a circle with a radius of a preset value R, and use it as the target circle. The target circle is within the target surface, and the target surface is the plane where point A is located in the three-dimensional space model. The target circles are merged to obtain the target range; A cooling pipe is installed on the battery surface along the target line, the average temperature within the target range is obtained in real time, and the flow rate of the coolant in the cooling pipe is controlled based on the PID control algorithm to ensure that the average temperature within the target range is within a preset temperature range.

2. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In step S2, when the total length of all representative curves in the first sorting is less than the total length threshold, the following steps are performed: Step 1: Set the similarity threshold , and regroup the projection lines, and determine again the total length of all representative curves in the first sorting, Indicates the preset similarity threshold adjustment value; When the total length of all representative curves in the new first sorting is less than the total length threshold, repeat the above steps; Step 2: When the similarity threshold P≥Pmax, if the total length of all representative curves in the corresponding first sorting is still less than the total length threshold, repeat steps S1-S2 to obtain projection lines again, and group the projection lines again, and repeat step 1, where Pmax represents the preset maximum similarity value, until the total length of all representative curves in the first sorting is greater than or equal to the total length threshold.

3. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In the step S3, when the flow rate of the coolant reaches the maximum flow rate and the average temperature within the target range is still rising, an early warning message is sent for prompting.

4. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In step S2, the process of determining the similarity of the projection lines specifically includes: A coordinate system is established with the preset position as the origin, the functional relationship of the projection line is determined, and the similarity of the projection line is determined based on the Fréchet distance.

5. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In the step S2, in the process of obtaining the first sorting, when two or more judgment numbers are the same, the representative line corresponding to the group with a larger total length of projection lines is ranked higher.

6. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In step S2, when the distances between point c on the contour line C and two or more planes in the three-dimensional space model are the same and are minimum, the following steps are performed: The plane with the same minimum distance from the three-dimensional space model to point c is taken as the undetermined plane, the proportion of the projection point corresponding to the contour line C in the undetermined plane is determined, and the undetermined plane corresponding to the maximum proportion is taken as the reference plane of point c.

7. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In the step S3, when the point A is on the intersection line B of two planes in the three-dimensional space model, a line segment with a length of R and a midpoint of A is determined on the intersection line B, and the line segment is used as the target circle corresponding to the point A.

8. A battery temperature control method based on new energy vehicles according to claim 1, characterized in that: In the step S2, the process of determining the representative line specifically includes: The projection line in the group is taken as the pending line, the pending line X is taken as the reference line, the total similarity PZ between the reference line and the pending line is determined, and the pending line corresponding to the maximum total similarity is taken as the representative line.

9. A battery temperature control system based on new energy vehicles, characterized in that: include: Acquisition module: Set several power nodes and duration nodes in the preset output power interval and battery single working time interval, determine N different working conditions, and the power nodes and / or duration nodes corresponding to different working conditions are different. The target number , n1 and n2 represent the total number of power nodes and duration nodes respectively; Constructing a three-dimensional space model of the battery, setting a plurality of collection points at preset distance intervals in the three-dimensional space model, obtaining the temperature at the collection points after the battery is operated in the ath working condition, and drawing temperature contour lines; Analysis module: determining the projection point of any point on the contour line on the reference surface, the reference surface being the surface in the three-dimensional space model that is closest to the point on the contour line, connecting the projection points on the surface of the three-dimensional space model to obtain a projection line; The projection lines are grouped, and the similarity between any two projection lines in the group is greater than a preset similarity threshold value P, a preset screening step is performed to determine a representative line in the group, and the representative lines are sorted in descending order according to the size of the judgment quantity to obtain a first sort, where the judgment quantity represents the total number of projection lines in the group corresponding to the representative line; Determine a target sorting position m in the first sorting, wherein the target sorting position m satisfies the constraint: and , represents the total length of the first m representative lines in the first sorting, Lys represents a preset total length threshold, and the representative lines at the first m sorting positions in the first sorting are taken as target lines; Control module: With point A on the target line as the center, a circle with a radius of a preset value R is drawn as the target circle, the target circle is within the target surface, and the target surface is the plane where point A is located in the three-dimensional space model, and the target circles are merged to obtain the target range; A cooling pipe is installed on the battery surface along the target line, the average temperature within the target range is obtained in real time, and the flow rate of the coolant in the cooling pipe is controlled based on the PID control algorithm to ensure that the average temperature within the target range is within a preset temperature range.

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