Analysis method and device for outlier battery cell and big data platform

Abstract

The application provides an analysis method and device for out-of-group battery cells and a big data platform. The analysis method calculates the standard deviation of the charging voltage, the standard deviation of the discharging voltage and the standard deviation of the voltage difference of all battery cells according to the charging voltage, the discharging voltage and the voltage difference of each battery cell, determines the comparison interval corresponding to the charging voltage, the discharging voltage and the voltage difference based on the standard deviation, determines the risk level of each battery cell by comparison with the comparison interval, and determines the out-of-group battery cell that needs to be compensated according to the risk level of the voltage difference, the charging voltage and the discharging voltage of each battery cell. The application can realize online analysis and determination of the out-of-group battery cell, does not need manual processing, and can improve the timeliness, accuracy and reliability of the out-of-group battery cell analysis, and has good practicability.

Description

Technical Field

[0001] This invention relates to the field of battery cell consistency analysis technology, and particularly to a method for analyzing outlier cells. The invention also relates to an apparatus for implementing the above-mentioned analysis method for outlier cells, and a big data platform capable of performing the above-mentioned analysis method. Background Technology

[0002] Battery packs in new energy vehicles or energy storage systems are generally composed of multiple cells. Due to differences in internal resistance between different cells, the amount of electricity charged by different cells in the same amount of time will vary during battery charging, and this difference will increase with the length of time the battery is used. The overall capacity of the battery pack is determined by the amount of electricity charged, i.e., the cell with the lowest capacity. If there is a cell with a low capacity, the overall capacity of the battery pack will decrease by a factor of several (related to the number of cells connected in series). In this case, it is necessary to charge the low-capacity, i.e., the isolated cell.

[0003] Currently, the screening and analysis of outlier cells, i.e., cells with lower capacity, typically involves manual intervention by staff after a differential voltage alarm occurs in the battery pack. This manual process is not only time-consuming and labor-intensive, resulting in delayed analysis and processing of outlier cells, but also suffers from low accuracy and reliability, presenting significant shortcomings. Summary of the Invention

[0004] In view of this, the present invention aims to propose an analysis method for outlier cells, so as to improve the timeliness, accuracy and reliability of the analysis of outlier cells that require recharging.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for analyzing outlier battery cells, the method comprising:

[0007] The acquisition unit acquires the charging voltage U of each cell in a battery cluster after the charging is completed in one charge-discharge cycle. 充i The discharge voltage U after the discharge ends 放i And the voltage difference U between the charging voltage and the discharging voltage of each of the battery cells. 压差i ;

[0008] The processing unit determines the charging voltage U of each of the battery cells. 充i Discharge voltage U 放i and pressure difference U 压差i Calculate the average value of the charging voltage of all the battery cells respectively. The average discharge voltage of all the cells. and the average value of the voltage difference of all the cells.

[0009] The processing unit calculates based on the obtained average value. average value and average Calculate the standard deviation σ of the charging voltage of all the aforementioned cells respectively. 充 The standard deviation σ of the discharge voltage of all the cells 放 And the standard deviation U of all the aforementioned cell voltage differences 压差 ;

[0010] The processing unit calculates the standard deviation σ based on the obtained standard deviation. 充 Standard deviation σ 放 , and standard deviation U 压差 The charging voltage U of the battery cell is determined respectively. 充i The corresponding charging voltage comparison range, and the discharge voltage U of the battery cell. 放i The corresponding discharge voltage comparison range, and the voltage difference U with the battery cell. 压差i The corresponding differential pressure comparison range;

[0011] The processing unit processes the charging voltage U of each of the battery cells. 充i By comparing the charging voltage with the specified charging voltage range, the charging voltage risk level of each cell is determined, and the discharge voltage U of each cell is calculated. 放i By comparing the discharge voltage with the specified discharge voltage range, the discharge voltage risk level of each cell is determined, and the voltage difference U between the cells is calculated. 压差i The differential pressure risk level of each cell is determined by comparing it with the differential pressure comparison range.

[0012] The processing unit identifies cells whose differential pressure risk level, charging voltage risk level, and discharging voltage risk level all meet preset requirements as outlier cells that need to be recharged.

[0013] Furthermore, the charging voltage U of each of the aforementioned battery cells 充i The voltage after each of the aforementioned cells has finished charging and has been left to stand for a first preset time;

[0014] The discharge voltage U of each of the aforementioned cells 放i The voltage after each of the aforementioned cells has finished discharging and has been left to stand for a second preset time.

[0015] Furthermore, the range of the charging voltage comparison interval is as follows: The range of the discharge voltage comparison interval is: The range of the pressure difference comparison interval is:

[0016] Where m is a multiple, and m > 0.

[0017] Furthermore, the charging voltage U of the battery cell 充i exist Between, or in At that time, the charging voltage risk level of the battery cell was classified as low risk, and the charging voltage U of the battery cell was... 充i exist Between, or in During this period, the charging voltage risk level of the battery cell is medium risk, and the charging voltage U of the battery cell is... 充i Less than or greater than At that time, the charging voltage risk level of the battery cell was classified as severe risk.

[0018] The discharge voltage U of the battery cell 放i exist Between, or in During this period, the discharge voltage risk level of the battery cell is classified as mild risk. Between, or in During this period, the discharge voltage risk level of the battery cell is medium risk, and the discharge voltage U of the battery cell is... 放i Less than or greater than At that time, the discharge voltage risk level of the battery cell was classified as severe risk.

[0019] The voltage difference U of the battery cell 压差i exist Between, or in At this time, the voltage drop risk level of the battery cell is mild, and the voltage drop U of the battery cell is... 压差i exist Between, or in At this time, the voltage drop risk level of the battery cell is medium risk, and the voltage drop U of the battery cell is... 压差i Less than or greater than At that time, the voltage difference risk level of the battery cell was classified as severe risk.

[0020] Where 0 < m1 < m2 < m3.

[0021] Furthermore, the processing unit identifies cells whose differential pressure risk level, charging voltage risk level, and discharging voltage risk level are all of severe risk as outlier cells that require recharging.

[0022] Furthermore, after identifying the outlier cells that require recharging, the analysis method further includes:

[0023] The acquisition unit acquires the time T1 at which the outlier cell begins charging and the time V it is charged to during a charge-discharge cycle. avg and voltage V max The times T2 and T3;

[0024] The processing unit performs ampere-hour integration on the charging current of the outlier cells during the time period T1 to T2 to obtain the energy C. avg The charging current of the outlier cells during the time period T1 to T3 is integrated in ampere-hours to obtain the charge C. max ;

[0025] The processing unit determines the amount of electricity C. avg and the amount of electricity C max Determine the charge-replenishing capacity of the outlier battery cell;

[0026] Wherein, the voltage V avg The average voltage after all charging is completed, V max The highest voltage after the battery cell has finished charging;

[0027] The charge-replenishing capacity of the out-of-group battery cell is specified in the charge C. avg and the amount of electricity C max between.

[0028] Furthermore, the replenishment capacity of the out-of-systems cell is the amount of electricity C. avg Or, the replenishment capacity of the out-of-systems cell is the amount of electricity C. max Or, the replenishment capacity of the out-of-systems cell is the amount of electricity C. avg and the amount of electricity C max The average value.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The outlier cell analysis method described in this invention is based on the acquisition unit obtaining the charging and discharging voltages during the cell's charging and discharging process. The processing unit calculates the standard deviation of the cell's charging, discharging, and voltage difference to determine a comparison range for assessing the risk level of the cell's charging and discharging voltages and voltage difference. After determining the risk level of the cell's charging and discharging voltages and voltage difference by comparing them with the comparison range, the outlier cells requiring recharging are identified based on their risk level. This method enables online analysis and identification of outlier cells without manual processing. Compared to manual processing, it not only improves the timeliness of analyzing and processing outlier cells requiring recharging but also enhances the accuracy and reliability of the analysis and processing by utilizing automatic data processing, thus demonstrating excellent practicality.

[0031] The present invention also proposes an analysis device for outlier cells, the analysis device comprising an acquisition unit and a processing unit, wherein the acquisition unit comprises a first acquisition module, the processing unit comprises a first calculation module, a second calculation module, a first determination module, a second determination module and a third determination module;

[0032] The acquisition module is used to acquire the charging voltage U of each cell in a battery cluster after charging is completed in one charge-discharge cycle. 充i The discharge voltage U after the discharge ends 放i And the voltage difference U between the charging voltage and the discharging voltage of each of the battery cells. 压差i ;

[0033] The first calculation module is used to calculate based on the charging voltage U of each of the battery cells. 充i Discharge voltage U 放i and pressure difference U 压差i Calculate the average value of the charging voltage of all the battery cells respectively. The average discharge voltage of all the cells. and the average value of the voltage difference of all the cells.

[0034] The second calculation module is used to calculate based on the obtained average value. average value and average Calculate the standard deviation σ of the charging voltage of all the aforementioned cells respectively. 充 The standard deviation σ of the discharge voltage of all the cells 放 And the standard deviation σ of all the cell voltage differences. 压差 ;

[0035] The first determining module is used to determine the standard deviation σ based on the obtained standard deviation σ. 充 Standard deviation σ 放 , and standard deviation σ 压差 The charging voltage U of the battery cell is determined respectively. 充i The corresponding charging voltage comparison range, and the discharge voltage u of the battery cell. 放i The corresponding discharge voltage comparison range, and the voltage difference U with the battery cell. 压差i The corresponding differential pressure comparison range;

[0036] The second determining module is used to determine the charging voltage U of each of the battery cells. 充i By comparing the charging voltage with the specified charging voltage range, the charging voltage risk level of each cell is determined, and the discharge voltage U of each cell is calculated. 放i By comparing the discharge voltage with the specified discharge voltage range, the discharge voltage risk level of each cell is determined, and the voltage difference U between the cells is calculated.压差i The differential pressure risk level of each cell is determined by comparing it with the differential pressure comparison range.

[0037] The third determining module is used to determine the battery cells that meet the preset requirements for the differential pressure risk level, the charging voltage risk level, and the discharging voltage risk level as outlier battery cells that need to be recharged.

[0038] Furthermore, the acquisition unit also includes a second acquisition module, and the processing unit also includes a third calculation module and a fourth determination module;

[0039] The second acquisition unit module is used to, after determining the outlier cells that need to be recharged, acquire, within one charge-discharge cycle, the time T1 at which the outlier cells begin charging, and the charging voltage V. avg and voltage V max The times T2 and T3;

[0040] The third calculation module is used to perform ampere-hour integration on the charging current of the outlier cells during the time period T1 to T2 to obtain the energy C. avg The charging current of the outlier cells during the time period T1 to T3 is integrated in ampere-hours to obtain the charge C. max ;

[0041] The fourth determining module is used to determine the amount of electricity C. avg and the amount of electricity C max Determine the charge-replenishing capacity of the outlier battery cell;

[0042] Wherein, the voltage V avg The average voltage after all charging is completed, V max The highest voltage after the battery cell has finished charging;

[0043] The charge-replenishing capacity of the out-of-group battery cell is specified in the charge C. avg and the amount of electricity C max between.

[0044] In addition, the present invention also proposes a big data platform, which is connected to the battery pack of a new energy vehicle or energy storage system. The big data platform is equipped with a memory and an actuator. The memory stores a computer program. When the computer program is executed by the actuator, it can realize the analysis method of outlier cells as described above.

[0045] The analytical apparatus and big data platform described above in this invention have the same beneficial effects as the aforementioned analytical methods, and will not be repeated here. Attached Figure Description

[0046] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0047] Figure 1 This is a flowchart of the outlier cell analysis process in the analysis method described in this embodiment of the invention;

[0048] Figure 2 This is a schematic diagram illustrating the comparison range of charging voltage / discharging voltage / voltage difference as described in an embodiment of the present invention;

[0049] Figure 3 This is a flowchart of the capacity compensation analysis process in the analysis method described in the embodiments of the present invention;

[0050] Figure 4 This is a schematic diagram of the structure of the analysis device described in an embodiment of the present invention;

[0051] Explanation of reference numerals in the attached figures:

[0052] 100. Acquisition Unit; 200. Processing Unit;

[0053] 10. Acquisition Module; 20. First Calculation Module; 30. Second Calculation Module; 40. First Determination Module; 50. Second Determination Module; 60. Third Determination Module; 70. Second Acquisition Module; 80. Third Calculation Module; 90. Fourth Determination Module. Detailed Implementation

[0054] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0055] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0056] In the description of this invention, it should be noted that the use of terms such as "upper," "lower," "inner," and "outer," indicating orientation or positional relationship, is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the use of terms such as "first" and "second" is also for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] Furthermore, in the description of this invention, unless otherwise explicitly specified, the connecting structures between mating components can be conventional in the art. Moreover, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in light of the specific circumstances.

[0058] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] Example 1

[0060] This embodiment relates to an analysis method for outlier cells. This analysis method is used to screen the consistency of cells in a battery pack to identify outlier cells that need to be recharged. It can also determine the recharge capacity of outlier cells, thereby improving the efficiency of outlier cell analysis.

[0061] In terms of overall design, combined Figure 1 As shown, the analysis method of this embodiment first includes the following steps for identifying outlier cells.

[0062] Step s1: The acquisition unit 100 acquires the charging voltage U of each cell in a battery cluster after charging is completed in one charge-discharge cycle. 充i The discharge voltage U after the discharge ends 放i And the voltage difference U between the charging voltage and the discharging voltage of each cell. 压差i .

[0063] In step s1, the aforementioned cluster of batteries can be one or more selected battery modules in a battery pack, with a charging voltage U 充i Discharge voltage U 放i and pressure difference U 压差i The letter "i" in the name represents one of the battery cells.

[0064] The aforementioned acquisition unit 100 can be a cell data acquisition device in a vehicle or energy storage system equipped with the aforementioned battery pack, or it can be a data acquisition device in an external device (such as a big data platform) that is communicatively connected to the vehicle or energy storage system. Simultaneously, it can also acquire data about the charging voltage U after the cell charging is completed. 充i And the discharge voltage U after the discharge ends 放i The acquisition unit 100 can obtain the charging voltage U after the charging is completed through the Battery Management System (BMS). 充iand the discharge voltage U after the discharge ends 放i Then, based on the charging voltage U 充i -Discharge voltage U_amplifier i This allows us to obtain the voltage difference U between the charging voltage and the discharging voltage. 压差i .

[0065] Furthermore, as a preferred embodiment, in step s1, the charging voltage U of each battery cell is obtained. 充i For example, after each cell has finished charging, it can be left to stand for a first preset time before charging voltage U is applied. 充i Similarly, the discharge voltage U of each cell is obtained. 放i Alternatively, after each cell has finished discharging, it can be left to stand for a second preset time before the discharge voltage U is applied. 放i The acquisition of.

[0066] In practice, the first and second preset durations can both be, for example, 0.5 hours or other time values. Furthermore, it is understood that by allowing the battery cell to stand for a period of time after charging and discharging are complete, the charging voltage U of the battery cell can be adjusted. 充i and discharge voltage U 放i The acquisition of this allows the acquisition of the charging voltage U. 充i With discharge voltage U 放i More accurate, which helps to improve the effectiveness of the analysis method in this embodiment.

[0067] Step s2: Processing unit 200 calculates the charging voltage U of each battery cell. 充i Discharge voltage U 放i and pressure difference U 压差i Calculate the average charging voltage of all battery cells respectively. Average discharge voltage of all cells and the average value of the voltage difference of all cells

[0068] In step s2, the charging voltage U of each cell is obtained. 充i Discharge voltage U 放i and pressure difference U 压差i Then, the average charging voltage of all cells Specifically Average discharge voltage of all cells Specifically Average voltage difference of all cells Specifically

[0069] Where n represents the total number of battery cells.

[0070] Furthermore, the aforementioned processing unit 200 can also be a cell data acquisition device in a vehicle or energy storage system equipped with the aforementioned battery pack, or a related control device with data processing capabilities in an external device (such as a big data platform) that is communicatively connected to the vehicle or energy storage system. Moreover, in this embodiment, the processing unit 200 is not only connected to the acquisition unit 100 to transmit data, but can also perform corresponding data calculations, comparisons, and judgments based on the data acquired by the acquisition unit 100. Of course, the processing unit 200 in this embodiment can also transmit data with corresponding input / output units and other devices to output analysis results.

[0071] Step s3: Processing unit 200 calculates the average value obtained. average value and average Calculate the standard deviation σ of the charging voltage of all battery cells respectively. 充 The standard deviation σ of the discharge voltage of all cells 放 And the standard deviation σ of the voltage difference of all cells. 压差 .

[0072] In step s3, the average charging voltage of all cells is obtained. Average discharge voltage of all cells and the average value of the voltage difference of all cells Afterwards, the standard deviation σ of the charging voltage of all battery cells 充 Specifically The standard deviation σ of the discharge voltage of all cells 放 Specifically and the standard deviation σ of the voltage difference of all cells 压差 Specifically

[0073] Step s4: Processing unit 200 calculates the standard deviation σ based on the obtained standard deviation σ. 充 Standard deviation σ 放 , and standard deviation σ 压差 Determine the charging voltage U of the battery cell respectively. 充i The corresponding charging voltage comparison range, and the cell's discharge voltage U 放i The corresponding discharge voltage comparison range, and the voltage difference U with the battery cell. 压差i The corresponding pressure difference comparison range.

[0074] In step s4, based on the standard deviation σ of all obtained cell charging voltages... 充 The standard deviation σ of the discharge voltage of all cells 放 And the standard deviation σ of the voltage difference of all cells. 压差 As a preferred embodiment, the range of the above-mentioned charging voltage comparison interval can be, for example, as follows: The range of the above discharge voltage comparison interval can be, for example, as follows: The range of the aforementioned differential pressure comparison interval can be, for example, as follows: Where m is a multiple, and m > 0.

[0075] At this point, generally, when the charging voltage U of a certain battery cell... 充i When the charging voltage exceeds the aforementioned comparison range, the charging voltage of the battery cell can be considered risky. Similarly, when the discharge voltage U of a battery cell exceeds the range mentioned above, the charging voltage of the battery cell can be considered risky. 放i When the discharge voltage exceeds the aforementioned comparison range, the discharge voltage of the cell can be considered risky. When the voltage difference U of a certain cell... 压差i If the voltage difference exceeds the above-mentioned differential pressure comparison range, the voltage difference of the battery cell can be considered to be at risk.

[0076] The charging voltage, discharging voltage, and voltage difference of the battery cell mentioned above are risky. That is, there are problems with the voltage after the battery cell is fully charged, the voltage after the battery cell is fully discharged, and the voltage difference between the end of the charging and discharging processes. This causes differences between the battery cell and other battery cells, making the battery cell an outlier.

[0077] In this embodiment, based on the examples of the charging voltage comparison range, discharging voltage comparison range, and voltage difference comparison range above, further, in specific implementation, to better assess the risk of each battery cell, [the following is combined with...]. Figure 2 As shown, the multiple m in each of the aforementioned comparison intervals can also be made to take different multiple values, thereby making the charging voltage comparison interval, the discharging voltage comparison interval, and the differential pressure comparison interval all have multiple different ranges.

[0078] Specifically, for the aforementioned charging voltage comparison range, the multiples m within the range can be, for example, m1, m2, and m3, where 0 < m1 < m2 < m3, and the ranges of the charging voltage comparison range are also respectively... and

[0079] Similarly, for the above discharge voltage comparison interval, the multiples m in the range can also be m1, m2, and m3, and the ranges of the discharge voltage comparison interval are as follows: For the above pressure difference comparison interval, the multiples m in the range can also be m1, m2, and m3, and the ranges of the pressure difference comparison interval can be as follows:

[0080] Furthermore, since the above charging voltage comparison range, discharging voltage comparison range, and differential voltage comparison range all adopt... Figure 2 To illustrate, so in Figure 2In this context, +m1σ represents the above. or or +m2σ represents the above. or or +m3σ represents the above. or or Of course, -m1σ represents the above. or or -m2σ represents the above. or or -m3σ represents the above. or or

[0081] Step s5: Processing unit 200 converts the charging voltage U of each battery cell... 充i By comparing the charging voltage with the range of charging voltages, the risk level of each cell's charging voltage is determined, and the discharge voltage U of each cell is calculated. 放i By comparing the discharge voltage with the range of discharge voltage comparisons, the discharge voltage risk level of each cell is determined, and the voltage difference U between each cell is calculated. 压差i By comparing with the differential pressure comparison range, the differential pressure risk level of each cell can be determined.

[0082] In step s5, taking the charging voltage comparison range, discharging voltage comparison range, and differential voltage comparison range given in step s4 as examples, and each comparison range also includes the range when the multiple m takes m1, m2, and m3 respectively, the charging voltage U of each cell can be calculated. 充i Discharge voltage U 放i and pressure difference U 压差i The charging voltage U of each cell is determined by comparing it with the corresponding comparison interval. 充i Discharge voltage U 放i and pressure difference U 压差i The risk level.

[0083] Among them, in the charging voltage U 充i Discharge voltage U 放i Or pressure difference U 压差i When making comparisons, it is still necessary to combine Figure 2 As shown, for example, each cell can be represented by its own number to enable comparison and judgment of all cells.

[0084] In specific implementation, this embodiment may, for example, make the charging voltage U of the battery cell... 充i exist Between, or in At that time, the charging voltage risk level of the battery cell was classified as mild risk, and the charging voltage U of the battery cell was... 充i exist Between, or in During this period, the risk level of the battery cell's charging voltage was classified as medium risk, and the battery cell's charging voltage U... 充i Less than or greater than At that time, the charging voltage risk level of the battery cell is classified as severe risk.

[0085] Similarly, the discharge voltage U of the battery cell 放i exist Between, or in During this period, the discharge voltage risk level of the battery cell was classified as mild, while the discharge voltage of the battery cell... Between, or in During this period, the discharge voltage risk level of the battery cell is moderate, and the discharge voltage U of the battery cell is... 放i Less than or greater than At that time, the discharge voltage risk level of the battery cell was classified as severe risk.

[0086] The voltage difference U of the battery cell 压差i exist Between, or in During this period, the cell's voltage drop risk level is classified as mild, and the cell's voltage drop U... 压差i exist Between, or in At this point, the cell's voltage drop risk level is medium risk, and the cell's voltage drop U... 压差i Less than or greater than At that time, the voltage difference risk level of the battery cell was classified as severe risk.

[0087] The terms "mild risk," "medium risk," and "severe risk" all refer to the degree of deviation between the voltage or voltage difference of a certain battery cell and that of other battery cells. Of course, from mild risk to medium risk to severe risk, the degree of deviation increases, and the greater the degree of deviation, the more likely the battery cell is an outlier that needs to be recharged.

[0088] Step s6: The processing unit 200 identifies the cells whose differential pressure risk level, charging voltage risk level, and discharge voltage risk level all meet the preset requirements as outlier cells that need to be recharged.

[0089] In step s6, based on the charging voltage U of each cell in step s5 above... 充i Discharge voltage U 放i and pressure difference U 压差i The risk level can be determined by the charging voltage U of each battery cell. 充i Discharge voltage U 放i and pressure difference U 压差i The risk level of the cell determines whether it is an outlier cell.

[0090] It is worth noting that when determining outlier cells based on risk level, voltage difference can usually be used as the main indicator, supplemented by charging voltage and discharging voltage.

[0091] In this specific implementation, as a preferred embodiment, such as in this example, the processing unit 200 can generally identify cells with severe risk levels in terms of differential voltage risk, charging voltage risk, and discharge voltage risk as outlier cells that need to be recharged.

[0092] In addition to identifying cells with severe risk levels in differential voltage, charging voltage, and discharging voltage as outlier cells requiring recharging, when the differential voltage risk level is severe, generally, if the cell's charging voltage risk level is low while its discharging voltage risk level is high, or vice versa, then the cell itself may be faulty and needs to be replaced.

[0093] In this embodiment, after identifying the outlier cells requiring recharging through steps s1 to s6, the process continues... Figure 3 As shown in the figure, the analysis method of this embodiment further includes the following steps for determining the charging capacity of outlier cells.

[0094] Step s7: In one charge / discharge cycle, the acquisition unit 100 acquires the time T1 at which the outlier cell begins charging, and the time to which it is charged to voltage V. avg and voltage V max The times T2 and T3.

[0095] In step s7, the charge / discharge cycle at this time can be the same cycle as the charge / discharge cycle in step s1, or it can be a subsequent charge / discharge cycle.

[0096] In addition, the aforementioned voltage V avg Specifically, it refers to the average voltage after all charging is completed, as stated in the above V. max This represents the highest voltage after the cell charging is complete, and the values ​​at the start time T1 and the charging voltage V are also considered. avg and voltage V maxThe timing times T2 and T3 can also be achieved by setting the corresponding timing module based on the detection of the battery management system.

[0097] Step s8: Processing unit 200 performs ampere-hour integration on the charging current of the outlier cells during the time period T1 to T2 to obtain the charge C. avg The charging current of the outlier cells during the time period from T1 to T3 is integrated in ampere-hours to obtain the energy C. max .

[0098] In step s8, the charging current of the outlier cells during the time periods T1 to T2 and T1 to T3 is integrated in ampere-hours, that is, the charge C during these two time periods is obtained based on ∫Idt. avg With C max .

[0099] Step s9, Processing unit 200 according to power C avg and power C max Determine the charging capacity of the outlier cells.

[0100] In step s9, based on the electrical charge C obtained in step s8... avg With C max This allows us to determine the charging capacity of the outlier cell, and at this point, the charging capacity of the outlier cell is specifically determined by its charge C. avg and power C max Between, that is, at the power C avg and power C max A certain charge value is determined between the values ​​to determine the replenishment capacity of the outlier cell.

[0101] In practical implementation, preferably, the replenishment capacity of the out-of-systems battery cells can be, for example, the charge C. avg Alternatively, the charge-repairing capacity of an out-of-group battery cell can be the charge C. max Alternatively, the charging capacity of an isolated battery cell can also be expressed as the charge C. avg and power C max The average value.

[0102] The outlier cell analysis method in this embodiment adopts the design described above. It is based on the acquisition unit obtaining the charging voltage and discharging voltage during the charging and discharging process of the cell. The processing unit calculates the standard deviation of the charging, discharging, and voltage difference of the cell to determine the comparison range for judging the risk level of the charging and discharging voltage and voltage difference of the cell. After determining the risk level of the charging and discharging voltage and voltage difference of the cell by comparing with the comparison range, the outlier cells that need to be recharged are determined according to the risk level of the cell. This enables online analysis and determination of outlier cells without manual processing. Compared with manual processing, it not only improves the timeliness of the analysis and processing of outlier cells that need to be recharged, but also improves the accuracy and reliability of the analysis and processing of outlier cells that need to be recharged by using automatic data calculation and processing, thus having good practicality.

[0103] Example 2

[0104] This embodiment relates to an analysis device for outlier battery cells. This analysis device is used to implement the analysis method in Embodiment 1, combined with... Figure 4 As shown, in terms of overall structure, the analysis device of this embodiment includes an acquisition unit 100 and a processing unit 200. The acquisition unit 100 includes a first acquisition module 10, and the processing unit 200 includes a first calculation module 20, a second calculation module 30, a first determination module 40, a second determination module 50, and a third determination module 60.

[0105] The first acquisition module 10 is used to acquire the charging voltage U of each cell in a battery cluster after charging is completed in one charge-discharge cycle. 充i The discharge voltage U after the discharge ends 放i And the voltage difference U between the charging voltage and the discharging voltage of each cell. 压差i The first calculation module 20 mentioned above is used to calculate the charging voltage U of each battery cell. 充i Discharge voltage U 放i and pressure difference U 压差i Calculate the average charging voltage of all battery cells respectively. Average discharge voltage of all cells and the average value of the voltage difference of all cells The second calculation module 30 described above is used to calculate based on the obtained average value. average value and average Calculate the standard deviation σ of the charging voltage of all battery cells respectively. 充 The standard deviation σ of the discharge voltage of all cells 放 And the standard deviation σ of the voltage difference of all cells. 压差 ;

[0106] Furthermore, the first determining module 40 described above is used to determine the standard deviation σ based on the obtained standard deviation σ. 充Standard deviation σ 放 , and standard deviation σ 压差 Determine the charging voltage U of the battery cell respectively. 充i The corresponding charging voltage comparison range, and the cell's discharge voltage U 放i The corresponding discharge voltage comparison range, and the voltage difference U with the battery cell. 压差i The corresponding voltage difference comparison range. The second determining module 50 mentioned above is used to determine the charging voltage U of each cell. 充i By comparing the charging voltage with the range of charging voltages, the risk level of each cell's charging voltage is determined, and the discharge voltage U of each cell is calculated. 放i By comparing the discharge voltage with the range of discharge voltage comparisons, the discharge voltage risk level of each cell is determined, and the voltage difference U between each cell is calculated. 压差i The differential pressure risk level of each cell is determined by comparing it with the differential pressure comparison range. The third determination module 60 is used to identify cells that meet the preset requirements for differential pressure risk level, charging voltage risk level and discharging voltage risk level as outlier cells that need to be recharged.

[0107] Furthermore, as before... Figure 4 As shown, in a preferred embodiment, the acquisition unit 100 of this embodiment further includes a second acquisition module 70, and the processing unit 200 further includes a third calculation module 80 and a fourth determination module 90.

[0108] The second acquisition module 70 is used, after determining the outlier cell that needs to be recharged, to acquire, within one charge-discharge cycle, the time T1 at which the outlier cell starts charging, and the charging voltage V. avg and voltage V max The time intervals T2 and T3 are used. The third calculation module 80 is used to perform ampere-hour integration on the charging current of the outlier cells during the time interval T1 to T2 to obtain the charge C. avg The charging current of the outlier cells during the time period from T1 to T3 is integrated in ampere-hours to obtain the energy C. max The fourth determining module 90 mentioned above is used to determine the amount of electricity C. avg and power C max Determine the charging capacity of the outlier cells.

[0109] Specifically, in conjunction with the relevant description in Embodiment 1, the analysis device of this embodiment can be installed in a vehicle or energy storage system, and can be integrated into the battery management system. In addition to being located in a vehicle or energy storage system, the analysis device of this embodiment can also be installed in other devices such as a big data platform that are connected to the vehicle or energy storage system, so as to perform the analysis and processing of cell consistency within the battery pack and the capacity of outlier cells.

[0110] Furthermore, as described in Embodiment 1, the modules described above in this embodiment can be circuit module units with corresponding data processing functions. In addition to the modules described above, in specific implementations, the analysis device in this embodiment will typically also include modules such as a storage module and other necessary modules. The storage module can store the control instructions involved in the analysis device of this embodiment, while other necessary modules typically include input / output modules, etc., which will not be described in detail here.

[0111] The specific working process of the analysis device in this embodiment, namely the screening of outlier cells in the battery pack and the determination of the capacitance of outlier cells, can be found in the relevant description in Embodiment 1.

[0112] The outlier cell analysis device of this embodiment adopts the above configuration and implements the analysis method in Embodiment 1. Based on the acquisition of charging and discharging voltages during the charging and discharging process of the cell, it calculates the standard deviation of the charging, discharging, and voltage difference of the cell to determine the comparison range for judging the risk level of the charging and discharging voltage and voltage difference of the cell. After determining the risk level of the charging and discharging voltage and voltage difference of the cell by comparing with the comparison range, it identifies the outlier cells that need to be recharged according to the risk level of the cell. This enables online analysis and determination of outlier cells without manual processing. Compared with manual processing, it not only improves the timeliness of the analysis and processing of outlier cells that need to be recharged, but also improves the accuracy and reliability of the analysis and processing of outlier cells that need to be recharged by using automatic data calculation and processing, thus having good practicality.

[0113] Example 3

[0114] This embodiment relates to a big data platform that connects to the battery pack of a new energy vehicle or energy storage system. Specifically, the battery management system and other control devices used to detect the battery pack, the entire vehicle, or the entire energy storage system are connected to the big data platform via the Internet of Things, enabling the transmission of various relevant parameter information of the battery pack during operation to the big data platform.

[0115] Meanwhile, the big data platform in this embodiment is equipped with a memory and an executor, and a computer program is stored in the memory. When the computer program is executed by the executor, it can implement the outlier cell analysis method in Embodiment 1.

[0116] In this embodiment, the memory is disposed on a permanent or non-permanent, removable or non-removable medium within the big data platform. It can be implemented using any method or technology to store information, i.e., computer programs. Examples of memory include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other memory technologies, CD-ROM, digital versatile optical disc (DVD), or other optical storage, magnetic tape, magnetic disk storage, or other magnetic storage devices, or any other non-transfer medium capable of storing information accessible by a computing device.

[0117] The big data platform in this embodiment, by executing the outlier cell analysis method in Embodiment 1, can timely, accurately, and reliably screen outlier cells in the battery packs of new energy vehicles or energy storage systems, and can also determine the charging capacity of outlier cells. This is beneficial for handling the cell consistency problem in battery packs and has good practicality.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for analyzing outlier battery cells, characterized in that, The analytical method includes: The acquisition unit (100) acquires the charging voltage of each cell in a battery cluster after charging is completed in one charge-discharge cycle. Discharge voltage after discharge ends And the voltage difference between the charging voltage and the discharging voltage of each of the aforementioned cells. ; The processing unit (200) determines the charging voltage of each of the battery cells. Discharge voltage and pressure difference Calculate the average charging voltage of all the battery cells respectively. The average value of the discharge voltage of all the aforementioned cells and the average value of the voltage difference of all the aforementioned cells. ; The processing unit (200) based on the obtained average value ,average value and average Calculate the standard deviation of the charging voltage of all the aforementioned cells respectively. The standard deviation of the discharge voltage of all the cells. and the standard deviation of all the aforementioned cell voltage differentials. ; The processing unit (200) calculates the standard deviation based on the obtained standard deviation. Standard deviation , and standard deviation The charging voltage of the battery cell is determined respectively. The corresponding charging voltage comparison range, and the discharge voltage of the battery cell. The corresponding discharge voltage comparison range, and the voltage difference with the battery cell. The corresponding differential pressure comparison range; The processing unit (200) calculates the charging voltage of each of the battery cells. By comparing the charging voltage with the specified range, the charging voltage risk level of each cell is determined, and the discharge voltage of each cell is... By comparing the discharge voltage with the specified discharge voltage range, the discharge voltage risk level of each cell is determined, and the voltage difference between each cell is calculated. The differential pressure risk level of each cell is determined by comparing it with the differential pressure comparison range. The processing unit (200) identifies the battery cells whose differential pressure risk level, charging voltage risk level and discharging voltage risk level all meet the preset requirements as outlier battery cells that need to be recharged. After identifying the outlier cells that require recharging, the analysis method further includes: The acquisition unit (100) acquires the time T1 at which the outlier cell begins charging and the time V at which it is charged to voltage V during one charge-discharge cycle. avg and voltage V max The times T2 and T3; The processing unit (200) performs ampere-hour integration on the charging current of the outlier cells during the time period T1 to T2 to obtain the energy C. avg The charging current of the outlier cells during the time period T1 to T3 is integrated in ampere-hours to obtain the charge C. max ; The processing unit (200) determines the amount of electricity C based on the amount of electricity C. avg and the amount of electricity C max Determine the charge-replenishing capacity of the outlier battery cell; Wherein, the voltage V avg The average voltage after all charging is completed, V max The highest voltage after the battery cell has finished charging; The charge-replenishing capacity of the out-of-group battery cell is specified in the charge C. avg and the amount of electricity C max between.

2. The method for analyzing outlier cells according to claim 1, characterized in that: Charging voltage of each of the aforementioned cells The voltage after each of the aforementioned cells has finished charging and has been left to stand for a first preset time; Discharge voltage of each of the aforementioned cells The voltage is the voltage after each of the battery cells has finished discharging and has been left to stand for a second preset time.

3. The method for analyzing outlier cells according to claim 1, characterized in that: The range of the charging voltage comparison interval is: ( - m )~( + m The range of the discharge voltage comparison interval is: ( - m )~( + m The range of the pressure difference comparison interval is: ( - m )~( + m ); Where m is a multiple, and m > 0.

4. The method for analyzing outlier cells according to claim 3, characterized in that: The charging voltage of the battery cell exist( - m2 )~( - m1 Between, or in ( + m1 )~( + m2 When the charging voltage of the battery cell is at a certain level, the risk level is considered low. exist( - m3 )~( - m2 Between, or in ( + m2 )~( + m3 When the voltage of the battery cell is between [a certain value] and [a certain value], the risk level of the battery cell's charging voltage is medium risk. Less than ( - m3 ), or greater than ( + m3 When the charging voltage risk level of the battery cell is high, the risk level is classified as severe. The discharge voltage of the battery cell exist( - m2 )~( - m1 Between, or in ( + m1 )~( + m2 When the discharge voltage of the battery cell is between [a certain value] and [a certain value], the risk level of the discharge voltage of the battery cell is mild. ( - m3 )~( - m2 Between, or in ( + m2 )~( + m3 When the discharge voltage of the battery cell is between [a certain value] and [a certain value], the risk level of the discharge voltage of the battery cell is medium risk. Less than ( - m3 ), or greater than ( + m3 When the discharge voltage risk level of the battery cell is high, the risk level is classified as severe. The voltage difference of the battery cell exist( - m2 )~( - m1 Between, or in ( +m1 )~( +m2 When the voltage difference is between 0 and 1, the voltage drop risk level of the battery cell is classified as mild risk. exist( - m3 )~( - m2 Between, or in ( +m2 )~( +m3 When the voltage difference is between 0 and 1, the voltage drop risk level of the battery cell is medium risk. Less than ( -m3 ), or greater than ( + m3 When the voltage difference risk level of the battery cell is ), it is classified as severe risk. Where 0 < m1 < m2 < m3.

5. The method for analyzing outlier cells according to claim 4, characterized in that: The processing unit (200) identifies the battery cells whose differential pressure risk level, charging voltage risk level, and discharge voltage risk level are all of severe risk as outlier battery cells that need to be recharged.

6. The method for analyzing outlier cells according to claim 1, characterized in that: The charge-replenishing capacity of the out-of-group battery cell is the charge C. avg Or, the charging capacity of the out-of-systems cell is the charge C. max Or, the charging capacity of the out-of-systems cell is the charge C. avg and the amount of electricity C max The average value.

7. An analysis device for outlier battery cells, characterized in that: The analysis device includes an acquisition unit (100) and a processing unit (200), and the acquisition unit (100) includes a first acquisition module (10), and the processing unit (200) includes a first calculation module (20), a second calculation module (30), a first determination module (40), a second determination module (50) and a third determination module (60); The first acquisition module (10) is used to acquire the charging voltage of each cell in a cluster of batteries after charging is completed in one charge-discharge cycle. Discharge voltage after discharge ends And the voltage difference between the charging voltage and the discharging voltage of each of the aforementioned cells. ; The first calculation module (20) is used to calculate based on the charging voltage of each of the battery cells. Discharge voltage and pressure difference Calculate the average charging voltage of all the battery cells respectively. The average value of the discharge voltage of all the aforementioned cells and the average value of the voltage difference of all the aforementioned cells. ; The second calculation module (30) is used to calculate based on the obtained average value. ,average value and average Calculate the standard deviation of the charging voltage of all the aforementioned cells respectively. The standard deviation of the discharge voltage of all the cells. and the standard deviation of all the aforementioned cell voltage differentials. ; The first determining module (40) is used to determine the standard deviation based on the obtained standard deviation. Standard deviation , and standard deviation The charging voltage of the battery cell is determined respectively. The corresponding charging voltage comparison range, and the discharge voltage of the battery cell. The corresponding discharge voltage comparison range, and the voltage difference with the battery cell. The corresponding differential pressure comparison range; The second determining module (50) is used to determine the charging voltage of each of the battery cells. By comparing the charging voltage with the specified range, the charging voltage risk level of each cell is determined, and the discharge voltage of each cell is... By comparing the discharge voltage with the specified discharge voltage range, the discharge voltage risk level of each cell is determined, and the voltage difference between each cell is calculated. The differential pressure risk level of each cell is determined by comparing it with the differential pressure comparison range. The third determining module (60) is used to determine the battery cell that meets the preset requirements for the differential pressure risk level, the charging voltage risk level and the discharging voltage risk level as an outlier battery cell that needs to be recharged. The acquisition unit (100) further includes a second acquisition module (70), and the processing unit (200) further includes a third calculation module (80) and a fourth determination module (90). The second acquisition module (70) is used to, after determining the outlier cell that needs to be recharged, acquire, in one charge-discharge cycle, the time T1 at which the outlier cell starts charging, and the time to which it is charged to voltage V. avg and voltage V max The times T2 and T3; The third calculation module (80) is used to perform ampere-hour integration on the charging current of the outlier cells during the time period T1 to T2 to obtain the charge C. avg The charging current of the outlier cells during the time period T1 to T3 is integrated in ampere-hours to obtain the charge C. max ; The fourth determining module (90) is used to determine the amount of electricity C. avg and the amount of electricity C max Determine the charge-replenishing capacity of the outlier battery cell; Wherein, the voltage V avg The average voltage after all charging is completed, V max The highest voltage after the battery cell has finished charging; The charge-replenishing capacity of the out-of-group battery cell is specified in the charge C. avg and the amount of electricity C max between.

8. A big data platform, wherein the big data platform is connected to a battery pack of a new energy vehicle or energy storage system, characterized in that: The big data platform includes a memory and an actuator. The memory stores a computer program, and when the computer program is executed by the actuator, it can implement the analysis method for outlier cells as described in any one of claims 1 to 6.

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