A cell matching system for prolonging the life of a battery pack

Abstract

This invention relates to the field of battery cell pairing technology, and more particularly to a battery cell pairing system for extending battery pack life. The invention includes a cell feature extraction module, a cell feature analysis module, a cell feature recognition module, a cell feature determination module, and a cell pairing control module. The cell feature analysis module determines the performance tendency parameters of the cells to be paired, thus marking the cell groups. The cell feature recognition module determines the voltage response curves of several cells at a second discharge rate, determining the performance similarity coefficient and voltage drop parameters. The cell feature determination module marks characteristic cells to be paired. The cell pairing control module determines whether to proceed with cell pairing and identifies any cell anomaly risks. This invention enables preliminary analysis of cells based on static parameters and further dynamic performance determination of cells based on multi-rate voltage response curves, improving the efficiency and reliability of the battery cell pairing system.

Description

Technical Field

[0001] This invention relates to the field of battery cell assembly technology, and in particular to a battery cell assembly system for extending battery pack life. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage systems and other fields, battery packs need to meet the requirements of wide-rate discharge and complex operating conditions. In the early days, cell matching mainly relied on static parameters, and consistency matching was achieved by screening cells with similar values. Although the operation was simple and efficient, it had significant drawbacks. Static parameters could not reflect the voltage response differences of cells at different discharge rates, nor could they assess the degradation trend of cells in long-term cycling. New energy vehicle batteries need to meet the requirements of stable driving (low rate) and rapid acceleration (high rate) at the same time. However, a single rate test cannot capture the performance fluctuations of cells under different operating conditions. Therefore, improving the efficiency and reliability of cell matching systems is an urgent technical problem to be solved.

[0003] For example, Chinese Patent Publication No. CN119297362B discloses a cell grouping system that can extend the life of a battery pack, belonging to the field of control system technology. In particular, it relates to a cell grouping system that can extend the life of a battery pack. This invention provides the circuit hardware foundation for a cell grouping system that can extend the life of a battery pack. The invention includes a local host processor, a node host and touch screen connection communication part, a host RS485 communication part, a node data upload part, a node host power supply part, a battery charging current acquisition part, a battery voltage acquisition part, a battery charging and discharging circuit part, an ADC acquisition and filtering circuit part, a slave master processor part, a slave RS485 communication part, a slave power supply part, a slave cell temperature control circuit part, and a battery discharge current ADC conversion circuit part.

[0004] The following problems still exist in the existing technology: Existing technologies do not consider the reliance on static parameters and ignore the differences in dynamic performance, making it difficult to meet the high requirements of new energy scenarios for battery pack life and safety. Existing technologies cannot perform preliminary analysis of battery cells based on static parameters, nor can they perform further dynamic performance judgment of battery cells based on multi-rate voltage response curves, which affects the efficiency and reliability of battery cell matching systems. Summary of the Invention

[0005] Therefore, the present invention provides a cell matching system for extending battery pack life, which overcomes the problems of existing technology that cannot perform preliminary analysis of cells based on static parameters, and cannot further determine the dynamic performance of cells based on multi-rate voltage response curves, thus affecting the efficiency and reliability of the cell matching system.

[0006] To achieve the above objectives, the present invention provides a cell matching system for extending battery pack life, comprising: The cell feature extraction module is used to obtain the capacity parameters, internal resistance parameters, and voltage parameters of the cells to be matched. A cell feature analysis module, which is connected to the cell feature extraction module, is used to determine the performance tendency parameters of the cells to be matched based on the capacity parameters and internal resistance parameters of the cells to be matched, and to mark the cell groups to be matched based on the performance tendency parameters of each cell to be matched. A cell feature identification module, which is connected to the cell feature extraction module and the cell feature analysis module respectively, is used to determine a number of cell voltage response curves based on the voltage parameters of each cell in the cell group to be matched at a preset second discharge rate at a certain time, and to determine the performance similarity coefficient and the second voltage drop parameter based on the cell voltage response curves. A cell feature determination module is connected to the cell feature extraction module and the cell feature recognition module respectively, and is used to obtain the cell voltage response curves of each cell in the cell group to be matched at a preset first discharge rate and a third discharge rate, and mark the characteristic cells to be matched based on the comparison of each voltage drop parameter. The cell pairing control module is connected to the cell feature extraction module and the cell feature determination module, respectively. It is used to determine whether to pair cells based on the performance similarity coefficient of the cells to be paired, and to determine whether there is a risk of cell abnormality based on the cells to be paired.

[0007] Furthermore, the cell characteristic analysis module is used to determine the performance tendency parameters of the cells to be matched, wherein, The cell feature analysis module obtains the capacity parameters and internal resistance parameters of the cells to be matched, and determines the ratio of the capacity parameters to the internal resistance parameters as the performance tendency parameters of the cells to be matched.

[0008] Furthermore, the cell feature analysis module is used to mark the cell groups to be matched, wherein, The cell feature analysis module marks the cells to be matched as the same cell group based on the judgment result that the performance tendency parameters of the cells to be matched meet the conditions of the cell group to be matched. The condition for the cell group to be matched is that the performance tendency parameter does not exceed a preset performance tendency parameter threshold, which is determined based on the average performance tendency parameter of several cells to be matched.

[0009] Furthermore, the second discharge rate exceeds the first discharge rate but does not exceed the third discharge rate.

[0010] Furthermore, the cell feature recognition module is used to determine several cell voltage response curves, wherein, The cell feature recognition module obtains the voltage parameters of the cells to be matched in the cell group at several moments under a preset second discharge rate. The cell voltage response curve is constructed by establishing a rectangular coordinate system with time as the horizontal axis and voltage parameters as the vertical axis.

[0011] Furthermore, the cell feature recognition module is used to determine the performance similarity coefficient of each cell in the cell group to be matched, wherein, The cell feature recognition module acquires the cell voltage response curve of each cell in the cell group to be matched at a preset second discharge rate. The average overlap of the cell voltage response curves of any cell to be paired with the other cells to be paired is determined as the performance similarity coefficient of the cell to be paired.

[0012] Furthermore, the cell feature recognition module is used to determine the second voltage drop parameter of each cell in the cell group to be matched, wherein, The cell feature recognition module obtains the slope at several data points on the cell voltage response curve, determines the data points that do not exceed the preset slope threshold as feature data points, and determines the horizontal coordinate value corresponding to the feature data points as voltage drop parameters. The second voltage drop parameter is determined based on the cell voltage response curve of the cells to be matched at a preset second discharge rate.

[0013] Furthermore, the cell feature determination module is used to mark characteristic cells to be matched, wherein, The cell feature determination module marks the cells to be matched as characteristic cells based on the comparison of voltage drop parameters of each cell in the cell group to be matched and the determination result that the comparison meets the conditions of the characteristic cell group. The characteristic cell group condition is that the second voltage drop parameter of the cell to be paired exceeds the third voltage drop parameter, but does not exceed the first voltage drop parameter.

[0014] Furthermore, the cell grouping control module is used to determine whether cell grouping should be performed, wherein, The cell grouping control module determines whether to perform cell grouping based on the judgment result that the performance similarity coefficient of the characteristic cells to be grouped meets the cell grouping conditions. The cell pairing condition is that the variance of the performance similarity coefficient of the characteristic cells to be paired does not exceed a preset variance threshold.

[0015] Furthermore, the cell grouping control module is used to determine whether there is a risk of cell abnormality, wherein, The cell grouping control module determines that there is a cell abnormality risk based on the judgment result that the number of characteristic cells to be grouped in the cell group meets the abnormal risk conditions. The abnormal risk condition is that the number of characteristic cells to be matched in the cell group does not exceed a preset quantity threshold.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention sets up a cell feature extraction module, a cell feature analysis module, a cell feature recognition module, a cell feature determination module, and a cell grouping control module. The cell feature extraction module obtains the capacity parameters, internal resistance parameters, and voltage parameters of the cells to be grouped. The cell feature analysis module determines the performance tendency parameters of the cells to be grouped based on the capacity and internal resistance parameters. Based on the performance tendency parameters of each cell to be grouped, cell groups are marked. The cell feature recognition module determines several cell voltage response curves based on the voltage parameters of each cell in the cell group at several moments under a preset second discharge rate. Based on the cell voltage... The response curve determines the performance similarity coefficient and the second voltage drop parameter. The cell characteristic judgment module obtains the cell voltage response curves of each cell in the cell group to be matched at the preset first discharge rate and third discharge rate. Based on the comparison of each voltage drop parameter, characteristic cells to be matched are marked. The cell matching control module determines whether to match cells based on the performance similarity coefficient of the characteristic cells to be matched, and determines whether there is a risk of cell abnormality based on the characteristic cells to be matched. Thus, it realizes the preliminary analysis of cells based on static parameters and the further dynamic performance judgment of cells based on multi-rate voltage response curves, thereby improving the efficiency and reliability of the cell matching system.

[0017] In particular, this invention uses a cell characteristic analysis module to label cell groups to be matched based on performance tendency parameters of each cell. It can be understood that the performance tendency parameters integrate the correlation characteristics of capacity and internal resistance, avoiding the limitations of grouping solely by capacity or internal resistance. Cells with smaller differences in performance tendency parameters exhibit more uniform voltage and energy distribution during charging and discharging, preventing some cells from prematurely aging due to excessive load, such as cells with high internal resistance overheating under high current, thus extending the overall lifespan of the battery pack. The performance tendency parameter threshold is dynamically determined based on the average value of the cells in the matched group, adaptable to different batches and models of batteries. The differences in cell characteristics avoid over- or under-screening issues caused by fixed thresholds, improving the practicality of cell pairing. Capacity parameters reflect the cell's ability to store charge, directly determining the battery pack's range. Internal resistance parameters reflect the cell's internal characteristics that impede current flow; higher internal resistance leads to greater energy loss during charging and discharging and more severe voltage fluctuations. Performance tendency parameters are a comprehensive quantification of the cell's energy output efficiency, reflecting the cell's overall performance more effectively than capacity or internal resistance alone. Thus, preliminary analysis of cells based on static parameters is achieved, improving the efficiency and reliability of cell pairing systems.

[0018] In particular, this invention uses a cell feature determination module to mark characteristic cells to be matched based on the comparison of various voltage drop parameters. It can be understood that, through a two-layer logic of intermediate rate benchmark analysis and high / low rate verification, it solves the problems of incomplete coverage by a single rate and low matching degree between dynamic characteristics and full operating conditions in traditional dynamic analysis. The performance similarity coefficient is calculated based on the overlap of intermediate rate voltage curves, quantifying subtle differences in cells during dynamic discharge. These differences cannot be identified through static parameters such as capacity and internal resistance. Voltage drop parameters are directly related to the voltage stability of the cell at the end of discharge. By screening cells with similar drop times, it can avoid battery... This approach avoids the waste of overall capacity caused by a cell prematurely triggering its cutoff voltage during battery pack discharge. It also reduces cell damage due to over-discharge, extending the battery pack's cycle life. By combining voltage drop parameter verification at three different rates, it ensures consistent cell performance across light, medium, and heavy load scenarios. Core dynamic characteristics are analyzed using intermediate rate curves, followed by targeted verification at high and low rates, rather than performing full analysis across all rates. This approach reduces testing complexity and time costs while maintaining matching accuracy. Furthermore, it enables further dynamic performance assessment of cells based on multi-rate voltage response curves, improving the efficiency and reliability of the cell matching system.

[0019] In particular, this invention uses a cell grouping control module to determine whether to perform cell grouping based on the performance similarity coefficient of the characteristic cells to be grouped. Furthermore, it determines whether there is a risk of cell anomalies based on the characteristic cells to be grouped. It is understood that by using variance screening of the performance similarity coefficient, the electrochemical characteristics of the grouped cells are ensured to be highly consistent, reducing uneven losses during charging and discharging, such as rapid capacity decay caused by overcharging and over-discharging of individual cells, thus extending the cycle life of the battery pack. Combined with the similarity of the voltage response curves, it more comprehensively reflects dynamic performance, resulting in higher grouping accuracy and better adaptability to complex operating conditions. Cell groups with consistent performance have more uniform voltage and current distribution during charging and discharging, avoiding risks such as fires and explosions caused by localized overheating or overvoltage of cells. The anomaly risk determination mechanism can identify substandard cell groups in advance, eliminating them at the source and reducing risks during later use. This reduces the probability of failure, minimizes subjective human judgment errors, and improves battery pack efficiency. Based on voltage response curves at the second discharge rate, the system allows the paired battery packs to better adapt to dynamically changing discharge demands in actual use, such as electric vehicle acceleration and peak discharge of energy storage devices, resulting in superior performance stability. The cells to be paired are those that have undergone multiple rounds of screening and meet specific performance standards. Their quantity directly reflects the overall quality of the cell group. A small quantity indicates that most cells have not passed the initial screening, potentially leading to batch quality fluctuations or individual defects. Early identification of abnormal risks can prevent unqualified cell groups from flowing into downstream processes, reducing return and repair costs, and minimizing losses to terminal equipment due to battery failures. Furthermore, it enables further dynamic performance judgment of cells based on multi-rate voltage response curves, improving the efficiency and reliability of the cell pairing system. Attached Figure Description

[0020] Figure 1 This is a functional block diagram of a cell matching system for extending battery pack life according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the logic of marking cell groups to be matched in the cell feature analysis module according to an embodiment of the present invention. Figure 3 This is a logic flowchart of the cell feature determination module marking features of cells to be matched in an embodiment of the present invention; Figure 4 This is a flowchart illustrating the logic of the cell grouping control module in an embodiment of the present invention for determining whether to perform cell grouping. Detailed Implementation

[0021] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0022] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0023] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0024] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Please see Figure 1 The diagram shown is a functional block diagram of a cell grouping system for extending battery pack life according to an embodiment of the present invention. The cell grouping system for extending battery pack life according to the present invention includes: The cell feature extraction module is used to obtain the capacity parameters, internal resistance parameters, and voltage parameters of the cells to be matched. Specifically, the embodiments of the present invention do not limit the specific structure of the cell feature extraction module. Preferably, it can be a capacity tester, an internal resistance tester, or a voltage acquisition device to obtain the capacity parameters, internal resistance parameters, and voltage parameters of the cells to be matched. This will not be elaborated further.

[0026] A cell feature analysis module, which is connected to the cell feature extraction module, is used to determine the performance tendency parameters of the cells to be matched based on the capacity parameters and internal resistance parameters of the cells to be matched, and to mark the cell groups to be matched based on the performance tendency parameters of each cell to be matched. Specifically, the embodiments of the present invention do not limit the specific structure of the cell feature analysis module. Preferably, it can be a microprocessor used to determine performance tendency parameters and mark the cell groups to be matched, which will not be elaborated further.

[0027] A cell feature identification module, which is connected to the cell feature extraction module and the cell feature analysis module respectively, is used to determine a number of cell voltage response curves based on the voltage parameters of each cell in the cell group to be matched at a preset second discharge rate at a certain time, and to determine the performance similarity coefficient and the second voltage drop parameter based on the cell voltage response curves. Specifically, the embodiments of the present invention do not limit the specific structure of the cell feature identification module. Preferably, it can be a microprocessor used to determine several cell voltage response curves, determine the performance similarity coefficient and the second voltage drop parameter, which will not be elaborated further.

[0028] A cell feature determination module is connected to the cell feature extraction module and the cell feature recognition module respectively, and is used to obtain the cell voltage response curves of each cell in the cell group to be matched at a preset first discharge rate and a third discharge rate, and mark the characteristic cells to be matched based on the comparison of each voltage drop parameter. Specifically, the embodiments of the present invention do not limit the specific structure of the cell feature determination module. Preferably, it can be a microprocessor used to determine the cell voltage response curve and mark the features of the cells to be matched. This will not be elaborated further.

[0029] The cell pairing control module is connected to the cell feature extraction module and the cell feature determination module, respectively. It is used to determine whether to pair cells based on the performance similarity coefficient of the cells to be paired, and to determine whether there is a risk of cell abnormality based on the cells to be paired.

[0030] Specifically, the embodiments of the present invention do not limit the specific structure of the cell matching and control module. Preferably, it can be a microprocessor used to determine whether to perform cell matching and whether there is a risk of cell abnormality. This will not be elaborated further.

[0031] Specifically, the cell characteristic analysis module is used to determine the performance tendency parameters of the cells to be matched, wherein, The cell feature analysis module obtains the capacity parameters and internal resistance parameters of the cells to be matched, and determines the ratio of the capacity parameters to the internal resistance parameters as the performance tendency parameters of the cells to be matched.

[0032] Please see Figure 2 The diagram shown is a logic flowchart of the cell feature analysis module marking cell groups to be matched according to an embodiment of the present invention. The cell feature analysis module is used to mark cell groups to be matched. The cell feature analysis module marks the cells to be matched as the same cell group based on the judgment result that the performance tendency parameters of the cells to be matched meet the conditions of the cell group to be matched. If the performance tendency parameters of the cells to be matched do not meet the conditions of the cells to be matched, the cell feature analysis module will not mark the cells to be matched as the same cells to be matched. The condition for the cell group to be matched is that the performance tendency parameter does not exceed a preset performance tendency parameter threshold, which is determined based on the average performance tendency parameter of several cells to be matched.

[0033] Specifically, the preset performance tendency parameter threshold can be the product of the average performance tendency parameter of the cells to be matched and the performance tendency coefficient. The performance tendency coefficient can be in the range of [1.1, 1.2]. Here, a value of 1.15 is given.

[0034] Specifically, in this embodiment of the invention, a cell feature analysis module marks the cell groups to be matched based on the performance tendency parameters of each cell. It can be understood that the performance tendency parameters integrate the correlation characteristics of capacity and internal resistance, avoiding the limitations of grouping solely by capacity or internal resistance. Cells with smaller differences in performance tendency parameters exhibit more uniform voltage distribution and energy allocation during charging and discharging, preventing some cells from prematurely aging due to excessive load, such as cells with high internal resistance overheating under high current, thus extending the overall lifespan of the battery pack. The performance tendency parameter threshold is dynamically determined based on the average value of the cells in the matched groups, adaptable to different batches and different... The differences in characteristics between different battery cell models avoid over- or under-screening issues caused by fixed thresholds, improving the practicality of battery pack matching. Capacity parameters reflect the cell's ability to store charge, directly determining the battery pack's range. Internal resistance parameters reflect the cell's internal characteristics that impede current flow; higher internal resistance leads to greater energy loss during charging and discharging and more severe voltage fluctuations. Performance tendency parameters provide a comprehensive quantification of the cell's energy output efficiency, reflecting the cell's overall performance more effectively than capacity or internal resistance alone. This allows for preliminary analysis of cells based on static parameters, improving the efficiency and reliability of the battery cell matching system.

[0035] Specifically, the second discharge rate exceeds the first discharge rate but does not exceed the third discharge rate.

[0036] Specifically, the preset first discharge rate can be 0.2C to 0.5C, the preset second discharge rate can be 1C to 2C, and the preset third discharge rate can be 3C to 5C. Preferably, the first discharge rate can be 0.3C, the second discharge rate can be 1.5C, and the third discharge rate can be 4C.

[0037] Specifically, the cell feature recognition module is used to determine several cell voltage response curves, wherein, The cell feature recognition module obtains the voltage parameters of the cells to be matched in the cell group at several moments under a preset second discharge rate. The cell voltage response curve is constructed by establishing a rectangular coordinate system with time as the horizontal axis and voltage parameters as the vertical axis.

[0038] Specifically, the cell feature recognition module is used to determine the performance similarity coefficient of each cell in the cell group to be matched, wherein, The cell feature recognition module acquires the cell voltage response curve of each cell in the cell group to be matched at a preset second discharge rate. The average overlap of the cell voltage response curves of any cell to be paired with the other cells to be paired is determined as the performance similarity coefficient of the cell to be paired.

[0039] Specifically, the cell feature recognition module is used to determine the second voltage drop parameter of each cell in the cell group to be matched, wherein, The cell feature recognition module obtains the slope at several data points on the cell voltage response curve, determines the data points that do not exceed the preset slope threshold as feature data points, and determines the horizontal coordinate value corresponding to the feature data points as voltage drop parameters. The second voltage drop parameter is determined based on the cell voltage response curve of the cells to be matched at a preset second discharge rate.

[0040] Specifically, the preset slope threshold is the product of the slope reference value and the slope value factor. The slope reference value is the average slope in historical data, and the slope value factor can be in the range of [1.1, 1.3], preferably 1.2.

[0041] Please see Figure 3 The diagram shown is a logic flowchart of the cell feature determination module marking characteristic cells to be matched in an embodiment of the present invention. The cell feature determination module is used to mark characteristic cells to be matched in an embodiment of the present invention. The cell feature determination module marks the cells to be matched as characteristic cells based on the comparison of voltage drop parameters of each cell in the cell group to be matched and the determination result that the comparison meets the conditions of the characteristic cell group. If the comparison of the voltage drop parameters of each cell in the cell group to be matched does not meet the characteristics of the cell group, then the cell to be matched will not be marked. The characteristic cell group condition is that the second voltage drop parameter of the cell to be paired exceeds the third voltage drop parameter, but does not exceed the first voltage drop parameter.

[0042] Specifically, this invention uses a cell feature determination module to mark characteristic cells to be matched based on the comparison of various voltage drop parameters. It can be understood that, through a two-layer logic of intermediate rate benchmark analysis and high / low rate verification, it solves the problems of incomplete coverage by a single rate and low matching degree between dynamic characteristics and full operating conditions in traditional dynamic analysis. The performance similarity coefficient is calculated based on the overlap of intermediate rate voltage curves, quantifying subtle differences in cells during dynamic discharge. These differences cannot be identified by static parameters such as capacity and internal resistance. Voltage drop parameters are directly related to the voltage stability of the cell at the end of discharge. By screening cells with similar drop times, it can avoid… This method avoids the waste of overall capacity caused by a single cell prematurely triggering its cutoff voltage during battery pack discharge, while also reducing cell damage due to over-discharge and extending battery pack cycle life. By combining voltage drop parameter verification at three different rates, it ensures consistent cell performance across light, medium, and heavy load scenarios. Core dynamic characteristics are analyzed using intermediate rate curves, followed by targeted verification at high and low rates, rather than performing full analysis across all rates. This approach reduces testing complexity and time costs while maintaining matching accuracy. Furthermore, it enables further dynamic performance assessment of cells based on multi-rate voltage response curves, improving the efficiency and reliability of the cell matching system.

[0043] Please see Figure 4 The diagram shown is a flowchart illustrating the logic of the cell grouping control module in an embodiment of the present invention for determining whether to perform cell grouping. The cell grouping control module is used to determine whether to perform cell grouping. The cell grouping control module determines whether to perform cell grouping based on the judgment result that the performance similarity coefficient of the characteristic cells to be grouped meets the cell grouping conditions. If the performance similarity coefficient of the characteristic cells to be matched does not meet the cell matching conditions, cell matching will not be performed. The cell pairing condition is that the variance of the performance similarity coefficient of the characteristic cells to be paired does not exceed a preset variance threshold.

[0044] Specifically, the cell grouping control module is used to determine whether there is a risk of cell abnormality. The cell grouping control module determines that there is a cell abnormality risk based on the judgment result that the number of characteristic cells to be grouped in the cell group meets the abnormal risk conditions. If the number of characteristic cells in the cell group to be matched does not meet the abnormal risk conditions, then the existence of abnormal cell risk is not determined. The abnormal risk condition is that the number of characteristic cells to be matched in the cell group does not exceed a preset quantity threshold.

[0045] Specifically, the preset quantity threshold is the product of the quantity reference value and the quantity value factor. The quantity reference value is the average value of the quantity in historical data, and the quantity value factor can be in the range of [1.2, 1.4], preferably 1.3.

[0046] Specifically, in this embodiment of the invention, the cell grouping control module determines whether to perform cell grouping based on the performance similarity coefficient of the characteristic cells to be grouped. Furthermore, it determines whether there is a risk of cell anomalies based on the characteristic cells to be grouped. It is understood that by using variance screening of the performance similarity coefficient, the electrochemical characteristics of the grouped cells are ensured to be highly consistent, reducing uneven losses during charging and discharging, such as rapid capacity decay caused by overcharging and over-discharging of individual cells, thus extending the cycle life of the battery pack. Combined with the similarity of the voltage response curves, dynamic performance is more comprehensively reflected, resulting in higher grouping accuracy and better suitability for complex operating conditions. Cell groups with consistent performance have more uniform voltage and current distribution during charging and discharging, avoiding risks such as fires and explosions caused by localized overheating or overvoltage of cells. The anomaly risk determination mechanism can identify substandard cell groups in advance, eliminating them at the source and reducing the risk of later problems. By reducing the probability of failure during use and minimizing subjective judgment errors, the battery pack grouping efficiency is improved. Based on the voltage response curve screening at the second discharge rate, the grouped battery packs are better able to adapt to the dynamically changing discharge demands in actual use, such as electric vehicle acceleration and peak discharge of energy storage devices, resulting in better performance stability. The cells to be grouped are cells that have undergone multiple rounds of screening and meet specific performance standards. Their quantity directly reflects the overall quality of the group of cells to be grouped. If the quantity is small, it indicates that most cells have not passed the initial screening, and there may be batch quality fluctuations or individual defects. Early identification of abnormal risks can prevent unqualified cell groups from flowing into downstream links, reduce return and repair costs, and reduce the loss of terminal equipment due to battery failure. In this way, it is possible to further dynamically determine the performance of cells based on the voltage response curve at multiple rates, thereby improving the efficiency and reliability of the cell grouping system.

[0047] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cell pairing system for extending battery pack life, characterized in that, include: The cell feature extraction module is used to obtain the capacity parameters, internal resistance parameters, and voltage parameters of the cells to be matched. A cell feature analysis module, which is connected to the cell feature extraction module, is used to determine the performance tendency parameters of the cells to be matched based on the capacity parameters and internal resistance parameters of the cells to be matched, and to mark the cell groups to be matched based on the performance tendency parameters of each cell to be matched. A cell feature identification module, which is connected to the cell feature extraction module and the cell feature analysis module respectively, is used to determine a number of cell voltage response curves based on the voltage parameters of each cell in the cell group to be matched at a preset second discharge rate at a certain time, and to determine the performance similarity coefficient and the second voltage drop parameter based on the cell voltage response curves. A cell feature determination module is connected to the cell feature extraction module and the cell feature recognition module respectively, and is used to obtain the cell voltage response curves of each cell in the cell group to be matched at a preset first discharge rate and a third discharge rate, and mark the characteristic cells to be matched based on the comparison of each voltage drop parameter. The cell pairing control module is connected to the cell feature extraction module and the cell feature determination module, respectively. It is used to determine whether to pair cells based on the performance similarity coefficient of the cells to be paired, and to determine whether there is a risk of cell abnormality based on the cells to be paired.

2. The cell matching system for extending battery pack life according to claim 1, characterized in that, The cell characteristic analysis module is used to determine the performance tendency parameters of the cells to be matched, wherein... The cell feature analysis module obtains the capacity parameters and internal resistance parameters of the cells to be matched, and determines the ratio of the capacity parameters to the internal resistance parameters as the performance tendency parameters of the cells to be matched.

3. The cell matching system for extending battery pack life according to claim 2, characterized in that, The cell feature analysis module is used to mark the cell groups to be matched, wherein... The cell feature analysis module marks the cells to be matched as the same cell group based on the judgment result that the performance tendency parameters of the cells to be matched meet the conditions of the cell group to be matched. The condition for the cell group to be matched is that the performance tendency parameter does not exceed a preset performance tendency parameter threshold, which is determined based on the average performance tendency parameter of several cells to be matched.

4. The cell matching system for extending battery pack life according to claim 3, characterized in that, The second discharge rate exceeds the first discharge rate but does not exceed the third discharge rate.

5. The cell matching system for extending battery pack life according to claim 4, characterized in that, The cell feature recognition module is used to determine the voltage response curves of several cells, wherein... The cell feature recognition module obtains the voltage parameters of the cells to be matched in the cell group at several moments under a preset second discharge rate. The cell voltage response curve is constructed by establishing a rectangular coordinate system with time as the horizontal axis and voltage parameters as the vertical axis.

6. The cell grouping system for extending battery pack life according to claim 5, characterized in that, The cell feature recognition module is used to determine the performance similarity coefficient of each cell in the cell group to be matched, wherein... The cell feature recognition module acquires the cell voltage response curve of each cell in the cell group to be matched at a preset second discharge rate. The average overlap of the cell voltage response curves of any cell to be paired with the other cells to be paired is determined as the performance similarity coefficient of the cell to be paired.

7. The cell matching system for extending battery pack life according to claim 6, characterized in that, The cell feature recognition module is used to determine the second voltage drop parameter of each cell in the cell group to be matched, wherein... The cell feature recognition module obtains the slope at several data points on the cell voltage response curve, determines the data points that do not exceed the preset slope threshold as feature data points, and determines the horizontal coordinate value corresponding to the feature data points as voltage drop parameters. The second voltage drop parameter is determined based on the cell voltage response curve of the cells to be matched at a preset second discharge rate.

8. The cell pairing system for extending battery pack life according to claim 7, characterized in that, The cell feature determination module is used to mark cells with specific features to be matched, wherein... The cell feature determination module marks the cells to be matched as characteristic cells based on the comparison of voltage drop parameters of each cell in the cell group to be matched and the determination result that the comparison meets the conditions of the characteristic cell group. The characteristic cell group condition is that the second voltage drop parameter of the cell to be paired exceeds the third voltage drop parameter, but does not exceed the first voltage drop parameter.

9. The cell matching system for extending battery pack life according to claim 8, characterized in that, The cell pairing control module is used to determine whether cell pairing should be performed. The cell grouping control module determines whether to perform cell grouping based on the judgment result that the performance similarity coefficient of the characteristic cells to be grouped meets the cell grouping conditions. The cell pairing condition is that the variance of the performance similarity coefficient of the characteristic cells to be paired does not exceed a preset variance threshold.

10. The cell pairing system for extending battery pack life according to claim 9, characterized in that, The cell grouping control module is used to determine whether there is a risk of cell abnormality. The cell grouping control module determines that there is a cell abnormality risk based on the judgment result that the number of characteristic cells to be grouped in the cell group meets the abnormal risk conditions. The abnormal risk condition is that the number of characteristic cells to be matched in the cell group does not exceed a preset quantity threshold.

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