A method and system for controlling operating temperature of a lithium battery pack

Abstract

The present invention discloses a method and system for controlling the operating temperature of a lithium battery pack, and relates to the technical field of lithium battery pack temperature control. First, a lithium battery pack test module is constructed, and multiple temperature control data collection tests are carried out to obtain data on temperature, power and cooling device driving mode under different conditions; by processing and analyzing these data, input or output power characteristic data are extracted, and abnormal temperature distribution characteristic data are determined to evaluate the high temperature abnormality of the lithium battery pack; based on the analysis results, the cooling device driving mode change sequence is corrected, and the power reduction ratio of the BMS module is determined; the real-time input or output power change sequence of the lithium battery pack is identified by using a power characteristic matching library, and the cooling device is driven and the BMS module is controlled based on the matching results. Through the above technical scheme, the present invention realizes precise control of the temperature of the lithium battery pack and avoids the harm of high temperature to the lithium battery pack.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery pack temperature control, and in particular to a method and system for controlling the operating temperature of a lithium battery pack. Background Art

[0002] With the popularity of electric vehicles, energy storage systems and portable electronic devices, the performance and safety of lithium batteries as their core power source have received increasing attention. The operating temperature of lithium batteries is one of the key factors affecting their performance, life and safety. Especially in high temperature environments, the internal chemical reactions of lithium batteries will accelerate, which may cause safety problems such as overheating and even thermal runaway, seriously threatening the safe operation of the equipment and the safety of users' lives and property. Therefore, how to effectively control the operating temperature of lithium battery packs to avoid excessive temperatures and ensure that lithium batteries can work stably and safely under different environmental conditions has become a technical problem that needs to be solved in the industry.

[0003] Most of the existing lithium battery temperature control methods use passive heat dissipation measures. These methods have disadvantages such as low control accuracy and slow response speed, which are difficult to meet the needs of lithium battery temperature control in complex and changing use environments, especially the heat dissipation needs in high temperature environments. In particular, higher requirements are placed on the real-time and accuracy of lithium battery temperature control. Summary of the invention

[0004] The purpose of the present invention is to provide a control method and system that can effectively monitor the temperature of a lithium battery and control the temperature more accurately.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for controlling the operating temperature of a lithium battery pack, comprising:

[0007] Construct a lithium battery pack test module based on the battery pack structure, peripheral assembly structure and cooling device structure layout of the lithium battery pack, and construct several temperature control data collection tests for the lithium battery pack test module;

[0008] Based on the temperature control data collection test, the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence are determined, and based on the equivalent time correspondence method, the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence are internally factored;

[0009] Based on the characteristic performance of the input or output power change sequence on the timeline, the input or output power corresponding to the continuous time nodes in the input or output power change sequence is combined and intercepted, and the input or output power characteristic data is generated;

[0010] The step of analyzing the temperature distribution change sequence corresponding to the input or output power characteristic data to determine the abnormal temperature distribution characteristic data, and determining the abnormal degree of high temperature of the lithium battery pack based on the abnormal temperature distribution characteristic data;

[0011] Based on the abnormal degree of high temperature of the lithium battery pack, determine the correction factor of the cooling device drive mode change sequence and the power reduction ratio of the BMS module, and after correcting the cooling device drive mode change sequence, obtain the corrected cooling device drive mode change sequence;

[0012] The generated input or output power characteristic data are integrated to obtain a power characteristic matching library, and the power characteristic matching library is used to identify the real-time input or output power change sequence of the lithium battery pack, find the matching input or output power characteristic data, and drive the cooling device based on its corresponding corrected cooling device drive mode change sequence, and based on the corresponding power reduction ratio, drive the BMS module to control the real-time input or output power of the lithium battery pack.

[0013] In some embodiments disclosed in the present invention, the method of constructing a temperature distribution change sequence, an input or output power change sequence, and a cooling device driving mode change sequence includes:

[0014] Establishing a time reference line, and setting a number of time nodes on the time reference line based on a preset time interval;

[0015] Corresponding to each time node on the time reference line, there is associated a temperature distribution factor, input or output power, or cooling device driving strength, wherein the temperature distribution factor includes temperature values ​​of nodes at different positions of the lithium battery pack.

[0016] In some embodiments disclosed in the present invention, a method for combining and intercepting input or output powers corresponding to consecutive time nodes in an input or output power change sequence includes:

[0017] Based on the temperature distribution factors corresponding to different time nodes on the time reference line, several temperature value change curves corresponding to nodes at different positions are constructed;

[0018] Aligning several temperature value change curves, setting position weights for different position nodes, and determining the starting time node that needs attention based on the first trend characteristics of the different temperature value change curves, and determining the ending time node that needs attention based on the second trend characteristics of the different temperature value change curves;

[0019] The input or output power corresponding to the start time node and the end time node of interest is combined and intercepted.

[0020] In some embodiments disclosed in the present invention, based on the first trend characteristics of the different temperature value change curves, the method for determining the starting time node that needs attention includes:

[0021] Scan different temperature change curves. If the temperature change curve is just higher than the preset value, scan the trend characteristics of the temperature change curve.

[0022] When scanning the trend characteristics of each temperature value change curve, the product of the accumulated value of the temperature value and the corresponding weight coefficient is continuously counted and recorded as the single position temperature parameter of interest;

[0023] The sum of all single position temperature attention parameters is calculated to obtain the comprehensive position temperature attention parameter. If the comprehensive position temperature attention parameter is greater than or equal to the preset value, the corresponding time node is identified as the starting time node that needs attention;

[0024] Based on the second trend characteristics of the different temperature value change curves, the method for determining the end time node that needs attention includes:

[0025] Scan different temperature value change curves. If the temperature value change curve is greater than or equal to the preset value, and the up and down fluctuations remain within the preset range, and the holding time is greater than or equal to the preset time length, the time node corresponding to the holding time exactly equal to the preset time length is identified as the end time node.

[0026] In some embodiments disclosed in the present invention, a method for determining the abnormal degree of high temperature of a lithium battery pack based on abnormal temperature distribution characteristic data includes:

[0027] Calculate the average temperature change curve of the temperature change curves corresponding to nodes at different positions, and overlap and compare each temperature change curve with the average temperature change curve;

[0028] During the overlap comparison process, several time nodes are randomly selected, and the temperature difference values ​​of the temperature value change curve and the average temperature value change curve corresponding to the time nodes are calculated, and all temperature difference values ​​are summed to obtain a comprehensive temperature difference value;

[0029] During the overlap comparison process, the time node at which the temperature value change curve and the average temperature value change curve enter a downward trend is determined, and from the time node of the downward trend, the temperature value decrease of each of the temperature value change curve and the average temperature value change curve within a preset time interval is determined, and the temperature value decrease difference is calculated;

[0030] Based on the comprehensive temperature difference value and the temperature drop difference value, the abnormal degree of high temperature of the lithium battery pack is determined.

[0031] In some embodiments disclosed in the present invention, the method for determining the abnormal degree of high temperature of the lithium battery pack according to the comprehensive temperature difference value and the temperature drop difference value includes:

[0032] A temperature difference value array a[a1, a2, a3, ..., an] is set for the comprehensive temperature difference value, wherein a1 is the first preset temperature difference value, a2 is the second preset temperature difference value, a3 is the third preset temperature difference value, an is the nth preset temperature difference value, and a1<a2<a3<...<an, and an initial temperature abnormality degree array q[q1, q2, q3, ..., qn] is also set, wherein q1 is the first preset initial temperature abnormality degree, q2 is the second preset initial temperature abnormality degree array, q3 is the third preset initial temperature abnormality degree, qn is the nth preset initial temperature abnormality degree, and q1<q2<q3<...<qn;

[0033] Obtain the corresponding comprehensive temperature difference value a0 of each location node;

[0034] If a0<a1, the first preset initial temperature abnormality degree q1 is identified as the initial temperature abnormality degree of the location node;

[0035] If a1≤a0<a2, the second preset initial temperature abnormality degree q2 is identified as the initial temperature abnormality degree of the location node;

[0036] If a2≤a0<a3, the third preset initial temperature abnormality degree q3 is identified as the initial temperature abnormality degree of the location node;

[0037] …;

[0038] If an-1≤a0<an, the nth preset initial temperature anomaly degree qn is determined as the initial temperature anomaly degree of the position node;

[0039] A temperature value decrease difference value array [h1, h2, h3, ..., hn] is set for the temperature value decrease difference value, wherein h1 is the first preset temperature value decrease difference value, h2 is the second preset temperature value decrease difference value, h3 is the third preset temperature value decrease difference value, hn is the nth preset temperature value decrease difference value, and h1<h2<h3<…<hn is set, and an abnormality adjustment coefficient array k[k1, k2, k3, ..., kn] is set, wherein k1 is the first abnormality adjustment coefficient, k2 is the second abnormality adjustment coefficient, k3 is the third abnormality adjustment coefficient, kn is the nth abnormality adjustment coefficient, and 1>k1>k2>k3>...>kn>0;

[0040] Get the temperature drop difference h0 of the location node;

[0041] If h0

[0042] If h1≤h0<h2, the high temperature anomaly degree corresponding to the location node is q*k2;

[0043] If h2≤h0<h3, the high temperature anomaly degree corresponding to the location node is q*k3; ...;

[0045] If hn-1≤h0<hn, the degree of high temperature anomaly corresponding to the location node is q*kn.

[0046] In some embodiments disclosed in the present invention, based on the abnormal degree of high temperature of the lithium battery pack, the method for determining the correction factor and the power reduction ratio of the cooling device driving mode change sequence includes:

[0047] Analyze the preset abnormality degree interval to which the high temperature abnormality degree belongs, and determine the corresponding correction factor and power reduction ratio based on the preset abnormality degree interval;

[0048] Based on the determined correction factor, the driving intensity of the cooling device at the corresponding time node in the cooling device driving mode change sequence and the preset time period before the time node is corrected, and based on the power reduction ratio, the power reduction ratio is set at the time node where the high temperature abnormality occurs.

[0049] In some embodiments disclosed in the present invention, a method for identifying a real-time input or output power change sequence of a lithium battery pack using a power signature matching library includes:

[0050] Converting a real-time input or output power change sequence into a real-time input or output power change curve;

[0051] Scan each input or output power characteristic data in the power characteristic matching library, and randomly select input or output power values ​​of several time nodes for each input or output power characteristic data to form a power comparison data group, and associate the power comparison data group with the corresponding input or output power characteristic data;

[0052] The input or output power value in each power comparison data group is mapped to the real-time input or output power change curve. If the longitudinal difference value between each mapping point and the real-time input or output power change curve is less than or equal to a preset value, the input or output power characteristic data corresponding to the power comparison data group is marked as a match.

[0053] In some embodiments disclosed in the present invention, there is also disclosed a control system for operating temperature of a lithium battery pack, comprising:

[0054] ​The first module is used to construct a lithium battery pack test module for the battery pack structure, peripheral assembly structure and cooling device structure layout of the lithium battery pack, and to construct several temperature control data collection tests for the lithium battery pack test module;

[0055] The second module is used to determine the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence based on the temperature control data collection test, and to associate the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence with internal factors based on the equivalent time correspondence method;

[0056] The third module is used to combine and intercept the input or output power corresponding to the continuous time nodes in the input or output power change sequence based on the characteristic performance of the input or output power change sequence on the timeline, and generate input or output power characteristic data;

[0057] The fourth module is used to analyze the temperature distribution change sequence corresponding to the input or output power characteristic data, determine the abnormal temperature distribution characteristic data, and determine the high temperature abnormality degree of the lithium battery pack based on the abnormal temperature distribution characteristic data;

[0058] The fifth module is used to determine the correction factor of the cooling device drive mode change sequence and the power reduction ratio of the BMS module based on the abnormal degree of high temperature of the lithium battery pack, and after correcting the cooling device drive mode change sequence, obtain the corrected cooling device drive mode change sequence, integrate the generated input or output power characteristic data to obtain a power characteristic matching library, and use the power characteristic matching library to identify the real-time input or output power change sequence of the lithium battery pack, find the matching input or output power characteristic data, and drive the cooling device based on its corresponding corrected cooling device drive mode change sequence, and drive the BMS module to control the real-time input or output power of the lithium battery pack based on the corresponding power reduction ratio.

[0059] The present invention discloses a method and system for controlling the operating temperature of a lithium battery pack, and relates to the technical field of lithium battery pack temperature control. First, a lithium battery pack test module is constructed, and multiple temperature control data collection tests are carried out to obtain data on temperature, power and cooling device driving mode under different conditions; by processing and analyzing these data, input or output power characteristic data are extracted, and abnormal temperature distribution characteristic data are determined to evaluate the high temperature abnormality of the lithium battery pack; based on the analysis results, the cooling device driving mode change sequence is corrected, and the power reduction ratio of the BMS module is determined; the real-time input or output power change sequence of the lithium battery pack is identified by using a power characteristic matching library, and the cooling device is driven and the BMS module is controlled based on the matching results. Through the above technical scheme, the present invention realizes precise control of the temperature of the lithium battery pack and avoids the harm of high temperature to the lithium battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A method step diagram of a method for controlling the operating temperature of a lithium battery pack disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0062] The purpose of the present invention is to provide a control method and system that can effectively monitor the temperature of a lithium battery and control the temperature more accurately.

[0063] In order to achieve the above object, the present invention adopts the following technical solutions:

[0064] See also Figure 1 , a method for controlling the operating temperature of a lithium battery pack, comprising:

[0065] Step S100, constructing a lithium battery pack test module for the battery pack structure, peripheral assembly structure and cooling device structure layout of the lithium battery pack, and constructing several temperature control data collection tests for the lithium battery pack test module.

[0066] Constructing a lithium battery pack test module and conducting temperature control data collection tests are the basis of this technical solution. By simulating the battery pack structure, peripheral assembly structure, and cooling device structure layout in the actual use environment, it can be ensured that the collected data has practical application value. By conducting temperature control data collection tests multiple times, data on temperature, power, and cooling device driving mode under different conditions can be obtained, providing a sufficient basis for subsequent data analysis and strategy formulation.

[0067] Step S200, based on the temperature control data collection test, determine the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence, and based on the equivalent time correspondence method, internal factor association is performed on the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence.

[0068] Based on the results of the temperature control data acquisition test, the temperature distribution change sequence, input or output power change sequence, and cooling device drive mode change sequence can be determined. These three sequences represent the changes in temperature, power, and cooling device drive mode of the lithium battery pack during operation. By correlating the internal factors of these three sequences in the equivalent time correspondence method, the mutual influence between them can be analyzed, providing a basis for the subsequent temperature control strategy formulation.

[0069] In some embodiments disclosed in the present invention, the method of constructing a temperature distribution change sequence, an input or output power change sequence, and a cooling device driving mode change sequence includes:

[0070] Step S201: establish a time reference line, and set a number of time nodes on the time reference line based on a preset time interval.

[0071] Step S202, corresponding to each time node on the time reference line, is associated with a temperature distribution factor, input or output power or cooling device driving strength, wherein the temperature distribution factor includes temperature values ​​of nodes at different positions of the lithium battery pack.

[0072] Step S300, based on the characteristic performance of the input or output power variation sequence on the timeline, the input or output power corresponding to the continuous time nodes in the input or output power variation sequence is combined and intercepted, and input or output power characteristic data is generated.

[0073] The input or output power change sequence has certain characteristic performance on the timeline. By identifying and analyzing these characteristics, the input or output power corresponding to the continuous time nodes can be combined and intercepted to generate input or output power characteristic data. These data represent the power characteristics of the lithium battery pack under different working conditions and are an important basis for subsequent temperature control.

[0074] In some embodiments disclosed in the present invention, a method for combining and intercepting input or output powers corresponding to consecutive time nodes in an input or output power change sequence includes:

[0075] Step S301, constructing a number of temperature value change curves corresponding to nodes at different positions based on the temperature distribution factors corresponding to different time nodes on the time reference line;

[0076] Step S302, aligning a plurality of temperature value change curves, setting position weights for different position nodes, and determining a start time node that needs attention based on a first trend feature of the different temperature value change curves, and determining an end time node that needs attention based on a second trend feature of the different temperature value change curves;

[0077] Step S303: Combine and intercept the input or output power corresponding to the start time node and the end time node that need to be concerned.

[0078] In some embodiments disclosed in the present invention, based on the first trend characteristics of the different temperature value change curves, the method for determining the starting time node that needs attention includes:

[0079] Step 3021, scanning different temperature value change curves, if the temperature value change curve is just higher than the preset value, then scanning the trend characteristics of the temperature value change curve.

[0080] The purpose of this step is to preliminarily screen out temperature change curves that may have specific trend characteristics. By comparing the temperature change curves with the preset values, those curves that have just exceeded the preset values ​​can be identified. These curves represent certain specific thermal behaviors or events, so they need to be further scanned for trend characteristics.

[0081] Step S3022, when scanning the trend characteristics of each temperature value change curve, continuously count the product of the accumulated value of the temperature value and the corresponding weight coefficient, and record it as the single position temperature parameter of interest.

[0082] This step conducts a detailed trend characteristic analysis of the selected temperature value change curve. By continuously counting the product of the accumulated temperature value and the corresponding weight coefficient, the temperature focus parameter of a single location can be calculated. This parameter reflects the intensity or importance of the thermal behavior of the temperature value change curve at a specific location. The selection of the weight coefficient can be based on the importance of different temperature values ​​in practical applications.

[0083] Step S3023, summing up all single position temperature attention parameters to obtain a comprehensive position temperature attention parameter. If the comprehensive position temperature attention parameter is greater than or equal to a preset value, the corresponding time node is identified as the starting time node that needs attention.

[0084] In this step, all single position temperature attention parameters are summed to obtain the comprehensive position temperature attention parameter. This parameter comprehensively reflects the intensity or importance of the thermal behavior of the entire temperature value change curve. When the comprehensive position temperature attention parameter is greater than or equal to the preset value, it means that the thermal behavior of the temperature value change curve has reached a level that requires attention, so the corresponding time node is identified as the starting time node that requires attention.

[0085] Based on the second trend characteristics of the different temperature value change curves, the method for determining the end time node that needs attention includes:

[0086] Step S3024, scanning different temperature value change curves, if the temperature value change curve is greater than or equal to the preset value, and the up and down fluctuations remain within the preset range, and the holding time is greater than or equal to the preset time length, then the time node corresponding to the holding time exactly equal to the preset time length is identified as the end time node.

[0087] The purpose of this step is to determine the end time node of the temperature value change curve. First, scan the different temperature value change curves to find those curves that are greater than or equal to the preset value and whose up and down fluctuations remain within the preset range. These curves may represent the end stage of a certain thermal behavior or event. Then, check whether the time these curves maintain this state is greater than or equal to the preset time length. If so, the time node corresponding to the time that is exactly equal to the preset time length is identified as the end time node. This end time node represents the end of the specific trend characteristics of the temperature value change curve.

[0088] Step S400, analyzing the temperature distribution change sequence corresponding to the input or output power characteristic data, determining abnormal temperature distribution characteristic data, and determining the abnormal degree of high temperature of the lithium battery pack based on the abnormal temperature distribution characteristic data.

[0089] By analyzing the temperature distribution change sequence corresponding to the input or output power characteristic data, the abnormal temperature distribution characteristic data can be determined. These data represent the temperature distribution of the lithium battery pack under abnormal high temperature conditions. By evaluating the abnormal high temperature degree of the lithium battery pack based on the abnormal temperature distribution characteristic data, it can be determined whether the battery pack is within a safe operating temperature range and provide a basis for the subsequent control strategy formulation.

[0090] Step S500, based on the abnormal degree of high temperature of the lithium battery pack, determine the correction factor of the cooling device drive mode change sequence and the power reduction ratio of the BMS module, and after correcting the cooling device drive mode change sequence, obtain the corrected cooling device drive mode change sequence.

[0091] Based on the abnormal degree of high temperature of the lithium battery pack, the correction factor of the change sequence of the cooling device driving mode and the power reduction ratio of the BMS module can be determined. By correcting the cooling device driving mode, the cooling effect can be optimized and the temperature of the lithium battery pack can be reduced. At the same time, by reducing the power of the BMS module, the output power of the lithium battery pack can be reduced, thereby reducing the heat generation and further controlling the temperature of the lithium battery pack. The formulation of these two control strategies is based on the accurate assessment of the abnormal degree of high temperature of the lithium battery pack.

[0092] In some embodiments disclosed in the present invention, a method for determining the abnormal degree of high temperature of a lithium battery pack based on abnormal temperature distribution characteristic data includes:

[0093] Step S501, calculating the average temperature value change curve of the temperature value change curves corresponding to nodes at different positions, and performing an overlap comparison between each temperature value change curve and the average temperature value change curve.

[0094] Step S502, during the overlap comparison process, several time nodes are randomly selected, and the temperature difference values ​​between the temperature value change curve corresponding to the time nodes and the average temperature value change curve are calculated, and all temperature difference values ​​are summed to obtain a comprehensive temperature difference value.

[0095] Step S503, during the overlap comparison process, determine the time node when the temperature value change curve and the average temperature value change curve enter a downward trend, and from the time node of the downward trend, determine the temperature value decrease of the temperature value change curve and the average temperature value change curve within a preset time interval, and calculate the temperature value decrease difference.

[0096] Step S504, determining the abnormal degree of high temperature of the lithium battery pack based on the comprehensive temperature difference value and the temperature drop difference value.

[0097] In some embodiments disclosed in the present invention, the method for determining the abnormal degree of high temperature of the lithium battery pack according to the comprehensive temperature difference value and the temperature drop difference value includes:

[0098] Step S5041, a temperature difference value array a[a1, a2, a3, ..., an] is set for the comprehensive temperature difference value, wherein a1 is the first preset temperature difference value, a2 is the second preset temperature difference value, a3 is the third preset temperature difference value, an is the nth preset temperature difference value, and a1<a2<a3<...<an, and an initial temperature anomaly degree array q[q1, q2, q3, ..., qn] is also set, wherein q1 is the first preset initial temperature anomaly degree, q2 is the second preset initial temperature anomaly degree array, q3 is the third preset initial temperature anomaly degree, qn is the nth preset initial temperature anomaly degree, and q1<q2<q3<...<qn.

[0099] Step S5042, obtaining the corresponding comprehensive temperature difference value a0 of each location node.

[0100] If a0<a1, the first preset initial temperature abnormality degree q1 is identified as the initial temperature abnormality degree of the location node.

[0101] If a1≤a0<a2, the second preset initial temperature abnormality degree q2 is identified as the initial temperature abnormality degree of the location node.

[0102] If a2≤a0<a3, the third preset initial temperature abnormality degree q3 is identified as the initial temperature abnormality degree of the location node.

[0103] ….

[0104] If an-1≤a0<an, the nth preset initial temperature abnormality degree qn is determined as the initial temperature abnormality degree of the location node.

[0105] Step S5042, a temperature value decrease difference value array [h1, h2, h3, ..., hn] is set for the temperature value decrease difference value, wherein h1 is the first preset temperature value decrease difference value, h2 is the second preset temperature value decrease difference value, h3 is the third preset temperature value decrease difference value, hn is the nth preset temperature value decrease difference value, and h1<h2<h3<…<hn, and an abnormality degree adjustment coefficient array k[k1, k2, k3, ..., kn] is set, wherein k1 is the first abnormality degree adjustment coefficient, k2 is the second abnormality degree adjustment coefficient, k3 is the third abnormality degree adjustment coefficient, kn is the nth abnormality degree adjustment coefficient, and 1>k1>k2>k3>...>kn>0.

[0106] Step S5043, obtaining the temperature drop difference value h0 of the location node.

[0107] If h0

[0108] If h1≤h0<h2, the high temperature anomaly degree corresponding to the location node is q*k2.

[0109] If h2≤h0<h3, the high temperature anomaly degree corresponding to the location node is q*k3. ....

[0110] If hn-1≤h0<hn, the degree of high temperature anomaly corresponding to the location node is q*kn.

[0111] In some embodiments disclosed in the present invention, based on the abnormal degree of high temperature of the lithium battery pack, the method for determining the correction factor and the power reduction ratio of the cooling device driving mode change sequence includes:

[0112] Step S501 , analyzing the preset abnormality level interval to which the high temperature abnormality level belongs, and determining the corresponding correction factor and power reduction ratio based on the preset abnormality level interval.

[0113] ​Step S502, based on the determined correction factor, correct the cooling device driving intensity at the corresponding time node in the cooling device driving mode change sequence and in the preset time period before the time node, and set the power reduction ratio at the time node where the high temperature abnormality occurs based on the power reduction ratio.

[0114] Step S600, integrates the generated input or output power characteristic data to obtain a power characteristic matching library, and uses the power characteristic matching library to identify the real-time input or output power change sequence of the lithium battery pack, finds the matching input or output power characteristic data, and drives the cooling device based on its corresponding corrected cooling device drive mode change sequence, and drives the BMS module to control the real-time input or output power of the lithium battery pack based on the corresponding power reduction ratio.

[0115] The generated input or output power characteristic data are integrated to obtain a power characteristic matching library. This library contains the power characteristic data of the lithium battery pack under different working conditions. By using the power characteristic matching library to identify the real-time input or output power change sequence of the lithium battery pack, matching input or output power characteristic data can be found. Based on the corrected cooling device drive mode change sequence and power reduction ratio corresponding to these matching data, the cooling device can be driven and the BMS module can be controlled, thereby achieving precise control of the real-time input or output power of the lithium battery pack. The implementation of this step is based on a deep understanding and application of the power characteristics and temperature control strategies of the lithium battery pack.

[0116] In some embodiments disclosed in the present invention, a method for identifying a real-time input or output power change sequence of a lithium battery pack using a power signature matching library includes:

[0117] Step S601: converting a real-time input or output power change sequence into a real-time input or output power change curve.

[0118] Step S602, scan each input or output power characteristic data in the power characteristic matching library, and randomly select the input or output power values ​​of several time nodes for each input or output power characteristic data to form a power comparison data group, and associate the power comparison data group with the corresponding input or output power characteristic data.

[0119] In step S603, the input or output power value in each power comparison data group is mapped to the real-time input or output power change curve. If the longitudinal difference value between each mapping point and the real-time input or output power change curve is less than or equal to a preset value, the input or output power characteristic data corresponding to the power comparison data group is marked as a match.

[0120] In some embodiments disclosed in the present invention, there is also disclosed a control system for operating temperature of a lithium battery pack, comprising:

[0121] The first module is used to construct a lithium battery pack test module for the battery pack structure, peripheral assembly structure and cooling device structure layout of the lithium battery pack, and to construct several temperature control data collection tests for the lithium battery pack test module.

[0122] The second module is used to determine the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence based on the temperature control data collection test, and to associate the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence with internal factors based on the equivalent time correspondence method;

[0123] The third module is used to combine and intercept the input or output power corresponding to the continuous time nodes in the input or output power change sequence based on the characteristic performance of the input or output power change sequence on the timeline, and generate input or output power characteristic data.

[0124] The fourth module is used to analyze the temperature distribution change sequence corresponding to the input or output power characteristic data, determine the abnormal temperature distribution characteristic data, and determine the high temperature abnormality degree of the lithium battery pack based on the abnormal temperature distribution characteristic data.

[0125] The fifth module is used to determine the correction factor of the cooling device drive mode change sequence and the power reduction ratio of the BMS module based on the abnormal degree of high temperature of the lithium battery pack, and after correcting the cooling device drive mode change sequence, obtain the corrected cooling device drive mode change sequence, integrate the generated input or output power characteristic data to obtain a power characteristic matching library, and use the power characteristic matching library to identify the real-time input or output power change sequence of the lithium battery pack, find the matching input or output power characteristic data, and drive the cooling device based on its corresponding corrected cooling device drive mode change sequence, and drive the BMS module to control the real-time input or output power of the lithium battery pack based on the corresponding power reduction ratio.

[0126] The present invention discloses a method and system for controlling the operating temperature of a lithium battery pack, and relates to the technical field of lithium battery pack temperature control. First, a lithium battery pack test module is constructed, and multiple temperature control data collection tests are carried out to obtain data on temperature, power and cooling device driving mode under different conditions; by processing and analyzing these data, input or output power characteristic data are extracted, and abnormal temperature distribution characteristic data are determined to evaluate the high temperature abnormality of the lithium battery pack; based on the analysis results, the cooling device driving mode change sequence is corrected, and the power reduction ratio of the BMS module is determined; the real-time input or output power change sequence of the lithium battery pack is identified by using a power characteristic matching library, and the cooling device is driven and the BMS module is controlled based on the matching results. Through the above technical scheme, the present invention realizes precise control of the temperature of the lithium battery pack and avoids the harm of high temperature to the lithium battery pack.

[0127] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for controlling the operating temperature of a lithium battery pack, characterized in that: include: Construct a lithium battery pack test module based on the battery pack structure, peripheral assembly structure and cooling device structure layout of the lithium battery pack, and construct several temperature control data collection tests for the lithium battery pack test module; Based on the temperature control data collection test, the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence are determined, and based on the equivalent time correspondence method, the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence are internally factored; Based on the characteristic performance of the input or output power change sequence on the timeline, the input or output power corresponding to the continuous time nodes in the input or output power change sequence is combined and intercepted, and the input or output power characteristic data is generated; Analyze the temperature distribution change sequence corresponding to the input or output power characteristic data to determine abnormal temperature distribution characteristic data, and determine the abnormal degree of high temperature of the lithium battery pack based on the abnormal temperature distribution characteristic data; Based on the abnormal degree of high temperature of the lithium battery pack, determine the correction factor of the cooling device drive mode change sequence and the power reduction ratio of the BMS module, and after correcting the cooling device drive mode change sequence, obtain the corrected cooling device drive mode change sequence; The generated input or output power characteristic data are integrated to obtain a power characteristic matching library, and the power characteristic matching library is used to identify the real-time input or output power change sequence of the lithium battery pack, find the matching input or output power characteristic data, and drive the cooling device based on its corresponding corrected cooling device drive mode change sequence, and based on the corresponding power reduction ratio, drive the BMS module to control the real-time input or output power of the lithium battery pack.

2. A method for controlling the operating temperature of a lithium battery pack according to claim 1, characterized in that: The method of constructing a temperature distribution change sequence, an input or output power change sequence, and a cooling device driving mode change sequence includes: Establishing a time reference line, and setting a number of time nodes on the time reference line based on a preset time interval; Corresponding to each time node on the time reference line, there is associated a temperature distribution factor, input or output power, or cooling device driving strength, wherein the temperature distribution factor includes temperature values ​​of nodes at different positions of the lithium battery pack.

3. A method for controlling the operating temperature of a lithium battery pack according to claim 2, characterized in that: The method for combining and intercepting the input or output power corresponding to the continuous time nodes in the input or output power change sequence includes: Based on the temperature distribution factors corresponding to different time nodes on the time reference line, several temperature value change curves corresponding to nodes at different positions are constructed; Aligning several temperature value change curves, setting position weights for different position nodes, and determining the starting time node that needs attention based on the first trend characteristics of the different temperature value change curves, and determining the ending time node that needs attention based on the second trend characteristics of the different temperature value change curves; The input or output power corresponding to the start time node and the end time node of interest is combined and intercepted.

4. A method for controlling the operating temperature of a lithium battery pack according to claim 3, characterized in that: Based on the first trend characteristics of the different temperature value change curves, the method for determining the starting time node that needs attention includes: Scan different temperature change curves. If the temperature change curve is just higher than the preset value, scan the trend characteristics of the temperature change curve. When scanning the trend characteristics of each temperature value change curve, the product of the accumulated value of the temperature value and the corresponding weight coefficient is continuously counted and recorded as the single position temperature parameter of interest; The sum of all single position temperature attention parameters is calculated to obtain the comprehensive position temperature attention parameter. If the comprehensive position temperature attention parameter is greater than or equal to the preset value, the corresponding time node is identified as the starting time node that needs attention; Based on the second trend characteristics of the different temperature value change curves, the method for determining the end time node that needs attention includes: Scan different temperature value change curves. If the temperature value change curve is greater than or equal to the preset value, and the up and down fluctuations remain within the preset range, and the holding time is greater than or equal to the preset time length, the time node corresponding to the holding time exactly equal to the preset time length is identified as the end time node.

5. The method for controlling the operating temperature of a lithium battery pack according to claim 3, characterized in that: Based on the abnormal temperature distribution characteristic data, the method for determining the abnormal degree of high temperature of the lithium battery pack includes: Calculate the average temperature change curve of the temperature change curves corresponding to nodes at different positions, and overlap and compare each temperature change curve with the average temperature change curve; During the overlap comparison process, several time nodes are randomly selected, and the temperature difference values ​​of the temperature value change curve and the average temperature value change curve corresponding to the time nodes are calculated, and all temperature difference values ​​are summed to obtain a comprehensive temperature difference value; During the overlap comparison process, the time node at which the temperature value change curve and the average temperature value change curve enter a downward trend is determined, and from the time node of the downward trend, the temperature value decrease of each of the temperature value change curve and the average temperature value change curve within a preset time interval is determined, and the temperature value decrease difference is calculated; Based on the comprehensive temperature difference value and the temperature drop difference value, the abnormal degree of high temperature of the lithium battery pack is determined.

6. A method for controlling the operating temperature of a lithium battery pack according to claim 5, characterized in that: The method for determining the abnormal degree of high temperature of the lithium battery pack according to the comprehensive temperature difference value and the temperature drop difference value includes: A temperature difference value array a[a1, a2, a3, ..., an] is set for the comprehensive temperature difference value, wherein a1 is the first preset temperature difference value, a2 is the second preset temperature difference value, a3 is the third preset temperature difference value, an is the nth preset temperature difference value, and a1<a2<a3<...<an, and an initial temperature abnormality degree array q[q1, q2, q3, ..., qn] is also set, wherein q1 is the first preset initial temperature abnormality degree, q2 is the second preset initial temperature abnormality degree array, q3 is the third preset initial temperature abnormality degree, qn is the nth preset initial temperature abnormality degree, and q1<q2<q3<...<qn; Obtain the corresponding comprehensive temperature difference value a0 of each location node; If a0<a1, the first preset initial temperature abnormality degree q1 is identified as the initial temperature abnormality degree of the location node; If a1≤a0<a2, the second preset initial temperature abnormality degree q2 is identified as the initial temperature abnormality degree of the location node; If a2≤a0<a3, the third preset initial temperature abnormality degree q3 is identified as the initial temperature abnormality degree of the location node; …； If an-1≤a0<an, the nth preset initial temperature anomaly degree qn is determined as the initial temperature anomaly degree of the position node; A temperature value decrease difference value array [h1, h2, h3, ..., hn] is set for the temperature value decrease difference value, wherein h1 is the first preset temperature value decrease difference value, h2 is the second preset temperature value decrease difference value, h3 is the third preset temperature value decrease difference value, hn is the nth preset temperature value decrease difference value, and h1<h2<h3<…<hn is set, and an abnormality adjustment coefficient array k[k1, k2, k3, ..., kn] is set, wherein k1 is the first abnormality adjustment coefficient, k2 is the second abnormality adjustment coefficient, k3 is the third abnormality adjustment coefficient, kn is the nth abnormality adjustment coefficient, and 1>k1>k2>k3>...>kn>0; Get the temperature drop difference h0 of the location node; If h0<h1, the high temperature anomaly degree corresponding to the location node is q*k1; If h1≤h0<h2, the high temperature anomaly degree corresponding to the location node is q*k2; If h2≤h0<h3, the high temperature anomaly degree corresponding to the location node is q*k3; ...； If hn-1≤h0<hn, the degree of high temperature anomaly corresponding to the location node is q*kn.

7. A method for controlling the operating temperature of a lithium battery pack according to claim 1, characterized in that: Based on the abnormal degree of high temperature of the lithium battery pack, the method for determining the correction factor and the power reduction ratio of the cooling device driving mode change sequence includes: Analyze the preset abnormality degree interval to which the high temperature abnormality degree belongs, and determine the corresponding correction factor and power reduction ratio based on the preset abnormality degree interval; Based on the determined correction factor, the driving intensity of the cooling device at the corresponding time node in the cooling device driving mode change sequence and the preset time period before the time node is corrected, and based on the power reduction ratio, the power reduction ratio is set at the time node where the high temperature abnormality occurs.

8. The method for controlling the operating temperature of a lithium battery pack according to claim 1, characterized in that: The method for identifying the real-time input or output power change sequence of a lithium battery pack using a power signature matching library includes: Converting a real-time input or output power change sequence into a real-time input or output power change curve; Scan each input or output power characteristic data in the power characteristic matching library, and randomly select input or output power values ​​of several time nodes for each input or output power characteristic data to form a power comparison data group, and associate the power comparison data group with the corresponding input or output power characteristic data; The input or output power value in each power comparison data group is mapped to the real-time input or output power change curve. If the longitudinal difference value between each mapping point and the real-time input or output power change curve is less than or equal to a preset value, the input or output power characteristic data corresponding to the power comparison data group is marked as a match.

9. A control system for the operating temperature of a lithium battery pack, characterized in that: include: The first module is used to construct a lithium battery pack test module for the battery pack structure, peripheral assembly structure and cooling device structure layout of the lithium battery pack, and to construct several temperature control data collection tests for the lithium battery pack test module; The second module is used to determine the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence based on the temperature control data collection test, and to associate the temperature distribution change sequence, the input or output power change sequence, and the cooling device driving mode change sequence with internal factors based on the equivalent time correspondence method; The third module is used to combine and intercept the input or output power corresponding to the continuous time nodes in the input or output power change sequence based on the characteristic performance of the input or output power change sequence on the timeline, and generate input or output power characteristic data; The fourth module is used to analyze the temperature distribution change sequence corresponding to the input or output power characteristic data, determine the abnormal temperature distribution characteristic data, and determine the high temperature abnormality degree of the lithium battery pack based on the abnormal temperature distribution characteristic data; The fifth module is used to determine the correction factor of the cooling device drive mode change sequence and the power reduction ratio of the BMS module based on the abnormal degree of high temperature of the lithium battery pack, and after correcting the cooling device drive mode change sequence, obtain the corrected cooling device drive mode change sequence, integrate the generated input or output power characteristic data to obtain a power characteristic matching library, and use the power characteristic matching library to identify the real-time input or output power change sequence of the lithium battery pack, find the matching input or output power characteristic data, and drive the cooling device based on its corresponding corrected cooling device drive mode change sequence, and drive the BMS module to control the real-time input or output power of the lithium battery pack based on the corresponding power reduction ratio.

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