Outlier cell analysis method and device and big data platform

Abstract

The invention provides an outlier cell analysis method and device and a big data platform. According to the analysis method, the standard deviation of the charging voltage, the standard deviation of the discharging voltage and the standard deviation of the voltage difference of all the battery cells are calculated according to the obtained charging voltage, the obtained discharging voltage and the obtained voltage difference between the charging voltage and the discharging voltage of each battery cell, and comparison intervals corresponding to the charging voltage, the discharging voltage and the voltage difference of the battery cells are determined based on the standard deviation; and determining the risk level of each battery cell by comparing with the comparison interval, and determining an outlier battery cell needing to be charged according to the voltage difference of each battery cell, the risk level of the charging voltage and the risk level of the discharging voltage. According to the invention, online analysis and determination of the outlier cell can be realized, manual processing is not needed, timeliness, accuracy and reliability of outlier cell analysis can be improved, and the outlier cell analysis method has good practicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery cell consistency analysis, in particular to an analysis method of outlier battery cells, and the present application also relates to a device for implementing the analysis method of outlier battery cells and a big data platform capable of executing the analysis method. BACKGROUND

[0002] A battery pack in a new energy vehicle or an energy storage system is generally composed of multiple battery cells. Due to the difference in internal resistance between different battery cells, the amount of electricity charged into different battery cells will be different in the same time during battery charging, and this difference will become larger and larger as the use time increases. The capacity of the entire battery pack is determined by the charging amount, i.e., the capacity of the lowest battery cell. If there is a battery cell with lower capacity, the capacity of the entire battery pack will be reduced by a multiple (related to the number of battery cells in series), and at this time, the battery cell with lower capacity, i.e., the outlier battery cell, needs to be recharged.

[0003] Currently, the screening and analysis of outlier battery cells, i.e., battery cells with lower capacity, are usually performed by workers manually locating the outlier battery cells and calculating the recharging capacity according to relevant data after the battery pack appears a pressure difference alarm. The existing manual processing method not only consumes time and labor, but also causes the analysis and processing of outlier battery cells to be not timely, and in particular, the accuracy and reliability of the analysis and processing of outlier battery cells are low, which has great disadvantages. SUMMARY

[0004] Therefore, the present application aims to provide an analysis method of outlier battery cells to improve the timeliness, accuracy and reliability of the analysis of outlier battery cells that need to be recharged.

[0005] To achieve the above object, the technical scheme of the present application is as follows:

[0006] An analysis method of outlier battery cells, the analysis method comprising:

[0007] an acquisition unit acquiring the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i between the charging voltage and the discharging voltage of each battery cell in a cluster of battery cells after the charging and discharging of each battery cell are completed in one charging and discharging cycle, respectively;

[0008] a processing unit calculating the average value of the charging voltage U 充i , the average value of the discharging voltage U 放i and the average value of the voltage difference U 压差i of all the battery cells according to the charging voltage, the discharging voltage and the voltage difference of each battery cell, respectively; and the average value of the charging voltage of all the battery 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] wherein m is a multiple and m>0.

[0017] Further, the charging voltage U of the battery cell is 充i between U or between U , the charging voltage risk level of the battery cell is a mild risk, the charging voltage U of the battery cell is 充i between U or between U , the charging voltage risk level of the battery cell is a moderate risk, the charging voltage U of the battery cell is 充i less than U or greater than U , the charging voltage risk level of the battery cell is a severe risk;

[0018] The discharging voltage U of the battery cell is 放i between U or between U , the discharging voltage risk level of the battery cell is a mild risk, the discharging voltage U of the battery cell is between U or between U , the discharging voltage risk level of the battery cell is a moderate risk, the discharging voltage U of the battery cell is 放i less than U or greater than U , the discharging voltage risk level of the battery cell is a severe risk;

[0019] The pressure difference U of the battery cell is 压差i between U or between U , the pressure difference risk level of the battery cell is a mild risk, the pressure difference U of the battery cell is 压差i between U or between U , the pressure difference risk level of the battery cell is a moderate risk, the pressure difference U of the battery cell is 压差i less than U or greater than U , the pressure difference risk level of the battery cell is a severe risk;

[0020] wherein 0

[0021] Further, the processing unit determines the battery cell whose pressure difference risk level, charging voltage risk level and discharging voltage risk level are all severe risks as the off-grid battery cell that needs to be recharged.

[0022] Further, after determining the out-of-group battery cell that needs to be compensated, the analysis method further comprises:

[0023] The acquisition unit acquires the time T1 when the out-of-group battery cell starts charging, and the times T2 and T3 when the out-of-group battery cell is charged to the voltages V avg and V max respectively in one charging and discharging cycle.

[0024] The processing unit integrates the charging current of the out-of-group battery cell in the time period from T1 to T2 to obtain the electric quantity C avg , and integrates the charging current of the out-of-group battery cell in the time period from T1 to T3 to obtain the electric quantity C max .

[0025] The processing unit determines the compensation capacity of the out-of-group battery cell according to the electric quantity C avg and the electric quantity C max .

[0026] Wherein, the voltage V avg is the average voltage after all charging ends, and the voltage V max is the highest voltage after the battery cell finishes charging.

[0027] The compensation capacity of the out-of-group battery cell is between the electric quantity C avg and the electric quantity C max .

[0028] Further, the compensation capacity of the out-of-group battery cell is the electric quantity C avg , or the compensation capacity of the out-of-group battery cell is the electric quantity C max , or the compensation capacity of the out-of-group battery cell is the average of the electric quantity C avg and the electric quantity C max .

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

[0030] The analysis method of the out-of-group battery cell provided by the present application determines the comparison interval for determining the risk level of the charging and discharging voltage and the pressure difference of the battery cell through the calculation of the standard deviation of the charging and discharging voltage and the pressure difference of the battery cell by the processing unit based on the acquisition of the charging and discharging voltage of the battery cell by the acquisition unit, and determines the out-of-group battery cell that needs to be compensated according to the risk level of the battery cell after determining the risk level of the charging and discharging voltage and the pressure difference of the battery cell through comparison with the comparison interval. Thus, the analysis and determination of the out-of-group battery cell can be realized online without manual processing. Not only can the timeliness of the analysis and processing of the out-of-group battery cell that needs to be compensated be improved compared with manual processing, but also the accuracy and reliability of the analysis and processing of the out-of-group battery cell that needs to be compensated can be improved through automatic operation processing based on data, which has good 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 charging voltage of all the battery cells respectively. The average discharge voltage of all the aforementioned 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 determining a pressure difference risk level of each of the battery cells by comparing the pressure difference with the pressure difference comparison interval;

[0037] The third determination module is configured to determine the battery cell as an outlier battery cell requiring power compensation when the pressure difference risk level, the charging voltage risk level and the discharging voltage risk level all meet preset requirements.

[0038] Further, the acquisition unit further comprises a second acquisition module, and the processing unit further comprises a third calculation module and a fourth determination module.

[0039] The second acquisition module is configured to acquire time T1 when the outlier battery cell starts charging, and time T2 and T3 when the outlier battery cell is charged to voltage V avg and voltage V max respectively in one charging and discharging cycle after determining the outlier battery cell requiring power compensation.

[0040] The third calculation module is configured to integrate the charging current of the outlier battery cell in the period from T1 to T2 to obtain electric quantity C avg , and integrate the charging current of the outlier battery cell in the period from T1 to T3 to obtain electric quantity C max .

[0041] The fourth determination module is configured to determine the power compensation capacity of the outlier battery cell according to the electric quantity C avg and the electric quantity C max .

[0042] The voltage V avg is an average voltage after all charging ends, and the voltage V max is the highest voltage after the charging of the battery cell ends.

[0043] The power compensation capacity of the outlier battery cell is between the electric quantity C avg and the electric quantity C max .

[0044] In addition, the present application also proposes a big data platform, wherein the big data platform is connected with a battery pack of a new energy vehicle or an energy storage system, and the big data platform is provided with a memory and an executor, the memory stores a computer program, and the computer program is executed by the executor to realize the analysis method of the outlier battery cell.

[0045] The above analysis device and big data platform of the present application have the same beneficial effects as the above analysis method, and will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0046] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The illustrations, together with their description, serve to explain the application without limiting the application thereto.

[0047] Figure 1 Flow chart of the analysis process of the out-of-group battery cells in the analysis method according to the embodiment of the application;

[0048] Figure 2 Schematic diagram of the charging voltage / discharge voltage / voltage difference comparison interval according to the embodiment of the application;

[0049] Figure 3 Flow chart of the analysis process of the compensation capacity in the analysis method according to the embodiment of the application;

[0050] Figure 4 Schematic diagram of the analysis device according to the embodiment of the application;

[0051] Legend of reference signs:

[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 DESCRIPTION

[0054] It should be noted that the embodiments and features in the embodiments of the application can be combined with each other without conflict.

[0055] In the following description, specific details are set forth in order to provide a thorough understanding of the embodiments of the application. However, persons skilled in the art will understand that the application can be practiced without these specific details. In other instances, well-known structures have not been shown or described in detail in order not to obscure the application.

[0056] In the description of the application, it should be noted that if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer" and the like appear, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, if the terms "first", "second" and the like appear, they are also used for the purpose of description only and cannot be understood as indicating or implying relative importance.

[0057] Furthermore, in the description of the present application, unless otherwise explicitly defined, the components are connected by means of conventional connection structure in the art. Moreover, the terms "mount", "connect", "connection", and "connector" should be interpreted broadly. For example, it can be fixed connection, detachable connection, or integral connection; it can be mechanical connection, electrical connection; it can be direct connection, or indirect connection through an intermediate medium; it can be internal connection of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood in combination with specific circumstances.

[0058] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0059] Embodiment One

[0060] The present embodiment relates to an analysis method for analyzing outlier battery cells, which is used to screen the consistency of battery cells in a battery pack to determine the outlier battery cells that need to be compensated, and also to determine the compensation capacity of the outlier battery cells, thereby improving the efficiency of outlier battery cell analysis.

[0061] Overall design, in combination with Figure 1 shown in the present embodiment, the analysis method first includes the following steps of determining outlier battery cells.

[0062] Step s1, the acquisition unit 100 acquires the charging voltage U 充i , the discharging voltage U 放i , and the voltage difference U 压差i between the charging voltage and the discharging voltage of each battery cell in a cluster of batteries after charging and discharging in a charging and discharging cycle.

[0063] In step s1, the cluster of batteries can be one or more battery modules selected from the battery pack. The letter "i" in the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i represents a certain battery cell.

[0064] The above acquisition unit 100 can be a battery cell data acquisition device in a vehicle or energy storage system provided with the above battery pack, or it can also be a data acquisition device in an external device (such as a big data platform) in communication connection with the vehicle or energy storage system. At the same time, the acquisition unit 100 can obtain the charging voltage U 充i after charging and the discharging voltage U 放i after discharging through the battery management system (Battery Management System, BMS), and the charging voltage U 充iand the discharge voltage U 放i After that, based on the charging voltage U 充i - the discharge voltage U i , the voltage difference U 压差i between the charging voltage and the discharge voltage can also be obtained.

[0065] In addition, as a preferred implementation form, in step s1, when obtaining the charging voltage U 充i of each battery cell, for example, after the charging of each battery cell is completed, a first preset time length is allowed to elapse, and then the charging voltage U 充i is obtained. Similarly, when obtaining the discharge voltage U 放i of each battery cell, after the discharging of each battery cell is completed, a second preset time length is allowed to elapse, and then the discharge voltage U 放i is obtained.

[0066] In a specific implementation, the first preset time length and the second preset time length can be, for example, 0.5h or other time values. It can be understood that, by allowing a time length to elapse after the completion of charging and discharging, and then obtaining the charging voltage U 充i and the discharge voltage U 放i of the battery cell, the obtained charging voltage U 充i and the discharge voltage U 放i are more accurate, which helps to improve the effectiveness of the analysis method of the embodiment.

[0067] In step s2, the processing unit 200 calculates, according to the charging voltage U 充i , the discharge voltage U 放i , and the voltage difference U 压差i of each battery cell, the average value of the charging voltage of all battery cells the average value of the discharge voltage of all battery cells and the average value of the voltage difference of all battery cells

[0068] In step s2, after the charging voltage U 充i , the discharge voltage U 放i , and the voltage difference U 压差i of each battery cell are obtained, the average value of the charging voltage of all battery cells is specifically the average value of the discharge voltage of all battery cells is specifically the average value of the voltage difference of all battery cells is specifically

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

[0070] In addition, the processing unit 200 described above can also be an electric cell data acquisition device provided in a vehicle or an energy storage system provided with the battery pack described above, or a related control device with data operation processing function in an external device (such as a big data platform) in communication connection with the vehicle or the energy storage system. Moreover, the processing unit 200 of the present embodiment not only is connected with the acquisition unit 100 to transmit data, but also can perform corresponding data calculation, comparison and determination based on the data acquired by the acquisition unit 100. Of course, the processing unit 200 of the present embodiment can also perform data transmission with a corresponding input / output unit and the like to realize output of the analysis result.

[0071] In step s3, the processing unit 200 calculates the average value of the charging voltages of all the electric cells the average value of the discharging voltages of all the electric cells and the average value of the voltage differences of all the electric cells respectively. 充 放 压差 .

[0072] In step s3, the average value of the charging voltages of all the electric cells the average value of the discharging voltages of all the electric cells and the average value of the voltage differences of all the electric cells are obtained. 充 Specifically, the standard deviation σ of the charging voltages of all the electric cells 放 Specifically, the standard deviation σ of the discharging voltages of all the electric cells 压差 Specifically, the standard deviation σ of the voltage differences of all the electric cells

[0073] In step s4, the processing unit 200 determines, based on the obtained standard deviation σ 充 , the standard deviation σ 放 , and the standard deviation σ 压差 , the charging voltage comparison interval corresponding to the charging voltage U 充i of the electric cell, the discharging voltage comparison interval corresponding to the discharging voltage U 放i of the electric cell, and the voltage difference comparison interval corresponding to the voltage difference U 压差i of the electric cell.

[0074] In step s4, based on the obtained standard deviation σ 充 of the charging voltages of all the electric cells, the standard deviation σ 放 of the discharging voltages of all the electric cells, and the standard deviation σ 压差 of the voltage differences of all the electric cells, as a preferred implementation form, the range of the charging voltage comparison interval can be, for example: ​​​​The range of the above discharge voltage comparison interval may be, for example: The range of the above pressure difference comparison interval may be, for example: Wherein, m is a multiple, and m>0.

[0075] At this time, generally, when the charging voltage U 充i When the above charging voltage comparison interval is exceeded, it can be considered that the charging voltage of the battery cell is at risk. Similarly, when the discharge voltage U 放i When the above discharge voltage comparison interval is exceeded, it can be considered that the discharge voltage of the battery cell is at risk. When the pressure difference U 压差i When the above pressure difference comparison interval is exceeded, it can be considered that the pressure difference of the battery cell is at risk.

[0076] And the above charging voltage, discharge voltage and pressure difference of the battery cell at risk, that is, the voltage after the battery cell charging ends, the voltage after the battery cell discharging ends, and the voltage pressure difference after the battery cell charging and discharging ends, there is a problem, and it is different from other battery cells, so that the battery cell becomes an outlier.

[0077] In this embodiment, based on the above examples of charging voltage comparison interval, discharge voltage comparison interval and pressure difference comparison interval, further, in specific implementation, in order to better judge the risk of each battery cell, combined with Figure 2 As shown in the above, the multiple m in the range of each of the above comparison intervals may also take different multiple values, and further, the charging voltage comparison interval, the discharge voltage comparison interval and the pressure difference comparison interval all have multiple different ranges.

[0078] Specifically, for the above charging voltage comparison interval, the multiple m in its range may be m1, m2 and m3, respectively, wherein 0 and

[0079] Similarly, for the above discharge voltage comparison interval, the multiple m in its range may also be m1, m2 and m3, respectively, and the range of the discharge voltage comparison interval may be: For the above pressure difference comparison interval, the multiple m in its range may also be m1, m2 and m3, respectively, and the range of the pressure difference comparison interval may be:

[0080] Moreover, since the above charging voltage comparison interval, discharge voltage comparison interval and pressure difference comparison interval are all Figure 2 are shown, so in Figure 2In the embodiment, +m1σ means the above or or +m2σ means the above or or +m3σ means the above or or Of course, -m1σ means the above or or -m2σ means the above or or -m3σ means the above or or

[0081] In step s5, the processing unit 200 compares the charging voltage U 充i of each battery cell with the charging voltage comparison interval, determines the charging voltage risk level of each battery cell, compares the discharging voltage U 放i of each battery cell with the discharging voltage comparison interval, determines the discharging voltage risk level of each battery cell, compares the voltage difference U 压差i of each battery cell with the voltage difference comparison interval, and determines the voltage difference risk level of each battery cell.

[0082] In step s5, still taking the ranges of the charging voltage comparison interval, the discharging voltage comparison interval and the voltage difference comparison interval given in step s4 as examples, and each comparison interval also contains the ranges when the multiple m takes m1, m2 and m3 respectively, the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i of each battery cell can be compared with the corresponding comparison interval respectively, so as to determine the risk level of the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i of each battery cell.

[0083] In the comparison of the charging voltage U 充i , the discharging voltage U 放i or the voltage difference U 压差i , the number of each battery cell can represent itself, so as to realize the comparison and judgment of all battery cells, as shown in Figure 3

[0084] In the specific implementation, the embodiment can make the charging voltage U 充i of each battery cell in ​ 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 充i , the discharging voltage U 放i and the voltage difference U 压差i of each battery cell in the preceding step s5, the determination of the risk level thereof, the determination of whether it is an outlier battery cell can be made by the risk level of the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i .

[0090] It is worth noting that in determining the outlier battery cell based on the risk level, the voltage difference can generally be used as the main judgment index, and the charging voltage and the discharging voltage can be used as auxiliary judgment indexes.

[0091] At this time, in specific implementation, as a preferred implementation form, for example, in the present embodiment, generally, the processing unit 200 can determine the battery cell whose voltage difference risk level, charging voltage risk level and discharging voltage risk level are all severe risks as the outlier battery cell that needs to be supplemented with power.

[0092] In addition to determining the battery cell whose voltage difference risk level, charging voltage risk level and discharging voltage risk level are all severe risks as the outlier battery cell that needs to be supplemented with power. When the voltage difference risk level is severe, generally, if the charging voltage risk level of the battery cell is low and the discharging voltage risk level is high, or the charging voltage risk level is high and the discharging voltage risk level is low, it may be that the battery cell itself has a problem and needs to be replaced.

[0093] In the present embodiment, after determining the outlier battery cell that needs to be supplemented with power through the above steps s1 to s6, the analysis method of the present embodiment further includes the following step of determining the power supplementing capacity of the outlier battery cell, as shown in step s7. Figure 4

[0094] In step s7, the acquisition unit 100 acquires the time T1 when the charging of the outlier battery cell starts, and the times T2 and T3 when the charging to the voltage V avg and the voltage V max respectively is completed in one charging and discharging cycle.

[0095] In step s7, the charging and discharging cycle at this time can be the same cycle as the charging and discharging cycle in the preceding step s1, or it can be a subsequent charging and discharging cycle.

[0096] In addition, the voltage V avg is specifically the average voltage after all charging is completed, and the voltage V max is the highest voltage after the charging of the battery cell is completed, and the time T1 when the charging of the battery cell starts, and the times T2 and T3 when the charging to the voltage V avg and the voltage V max ​The time T2 and T3 can also be based on the detection of the battery management system, and can be achieved by setting a corresponding timing module.

[0097] Step s8, the processing unit 200 integrates the charging current of the out-of-group battery cell in the T1-T2 period to obtain the electric quantity C avg The charging current of the out-of-group battery cell in the T1-T3 period is integrated to obtain the electric quantity C max .

[0098] In step s8, the charging current of the out-of-group battery cell in the T1-T2 period and the T1-T3 period is integrated, that is, the electric quantity C avg and C max .

[0099] Step s9, the processing unit 200 determines the power supply capacity of the out-of-group battery cell according to the electric quantity C avg and the electric quantity C max .

[0100] In step s9, the power supply capacity of the out-of-group battery cell is determined according to the electric quantity C avg and the electric quantity C max . At this time, the power supply capacity of the out-of-group battery cell is between the electric quantity C avg and the electric quantity C max , that is, a certain electric quantity value between the electric quantity C avg and the electric quantity C max is determined as the power supply capacity of the out-of-group battery cell.

[0101] In specific implementation, preferably, the power supply capacity of the out-of-group battery cell can be the electric quantity C avg , or the power supply capacity of the out-of-group battery cell can be the electric quantity C max , or the power supply capacity of the out-of-group battery cell can also be the average value of the electric quantity C avg and the electric quantity C max .

[0102] The analysis method of the outlier battery cell of the embodiment adopts the design as above, which is based on the acquisition of the charging voltage and the discharging voltage of the battery cell in the charging and discharging process by the acquisition unit, the calculation of the standard deviation of the charging and discharging and the voltage difference of the battery cell by the processing unit, the determination of the comparison interval for determining the risk level of the charging and discharging voltage and the voltage difference of the battery cell, and the determination of the outlier battery cell that needs to be charged after the comparison with the comparison interval and the determination of the risk level of the battery cell. Thus, the online analysis and determination of the outlier battery cell can be realized without manual processing. Compared with manual processing, the timeliness of the analysis and processing of the outlier battery cell that needs to be charged can be improved, and the accuracy and reliability of the analysis and processing of the outlier battery cell that needs to be charged can be improved by automatic operation processing based on data, which has good practicality.

[0103] Embodiment Two

[0104] The embodiment relates to an analysis device of an outlier battery cell, which is used for implementing the analysis method in the embodiment one. Figure 4 As shown in the embodiment one, in the overall structure, the analysis device of the embodiment comprises an acquisition unit 100 and a processing unit 200, and the acquisition unit 100 comprises a first acquisition module 10, and the processing unit 200 comprises a first calculation module 20, a second calculation module 30, and a first determination module 40, a second determination module 50 and a third determination module 60.

[0105] The first acquisition module 10 is used for acquiring the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i between the charging voltage and the discharging voltage of each battery cell in a cluster after the charging and discharging of the battery cell are completed in one charging and discharging cycle. 充i 放i 压差i The first calculation module 20 is used for calculating the average value of the charging voltage of all battery cells , the average value of the discharging voltage of all battery cells and the average value of the voltage difference of all battery cells according to the charging voltage U 充i , the discharging voltage U 放i and the voltage difference U 压差i of each battery cell. The second calculation module 30 is used for calculating the standard deviation of the charging voltage of all battery cells 充 , the standard deviation of the discharging voltage of all battery cells 放 and the standard deviation of the voltage difference of all battery cells 压差 according to the average value , the average value and the average value .

[0106] In addition, the first determination module 40 is used for determining the outlier battery cell that needs to be charged according to the standard deviation 充, standard deviation σ 放 , and standard deviation σ 压差 , respectively, determine the charging voltage U 充i corresponding charging voltage comparison interval, the discharging voltage U 放i corresponding discharging voltage comparison interval, and the voltage difference U 压差i corresponding voltage difference comparison interval. The second determination module 50 is configured to compare the charging voltage U 充i of each battery cell with the charging voltage comparison interval, determine the charging voltage risk level of each battery cell, compare the discharging voltage U 放i of each battery cell with the discharging voltage comparison interval, determine the discharging voltage risk level of each battery cell, and compare the voltage difference U 压差i of each battery cell with the voltage difference comparison interval, determine the voltage difference risk level of each battery cell. The third determination module 60 is configured to determine the battery cell that meets the preset requirements in the voltage difference risk level, the charging voltage risk level and the discharging voltage risk level as the outlier battery cell that needs to be compensated.

[0107] In addition, further, as shown in Figure 4 , as a preferred implementation form, the acquisition unit 100 of the 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 configured to acquire the time T1 when the charging of the outlier battery cell starts, and the times T2 and T3 when the voltages V avg and V max are reached, respectively, in a charging and discharging cycle after the outlier battery cell that needs to be compensated is determined. The third calculation module 80 is configured to integrate the charging current of the outlier battery cell in the time period from T1 to T2 to obtain the electric quantity C avg , and integrate the charging current of the outlier battery cell in the time period from T1 to T3 to obtain the electric quantity C max . The fourth determination module 90 is configured to determine the compensation capacity of the outlier battery cell according to the electric quantities C avg and C max .

[0109] Specifically, in combination with the related description in Embodiment One, the analysis device of the embodiment can be arranged in a vehicle or an energy storage system, and can be integrated in a battery management system. In addition to being arranged in a vehicle or an energy storage system, the analysis device of the embodiment can also be arranged in other devices such as a big data platform in communication connection with the vehicle or the energy storage system, to be used for analyzing and processing the consistency of battery cells in a battery pack and the compensation capacity of outlier battery cells.

[0110] In addition, still in combination with the description in Embodiment One, the above modules of the present embodiment can adopt circuit module units with corresponding data processing functions. In addition to the above modules, of course, during specific implementation, the analysis device of the present embodiment will also generally be provided with storage modules and other necessary modules. The storage modules can store control instructions related to the analysis device of the present embodiment, and the other necessary modules generally include input / output modules and the like, which will not be described in detail here.

[0111] The specific working process of the analysis device of the present embodiment, i.e., the screening of the outlier battery cells in the battery pack and the determination of the capacity of the outlier battery cells, can be referred to the related description in Embodiment One.

[0112] The analysis device of the outlier battery cells of the present embodiment is configured as above and determines the comparison interval for determining the risk level of the charging and discharging voltages and the pressure difference of the battery cells through the analysis method in Embodiment One based on the acquisition of the charging and discharging voltages and the pressure difference of the battery cells during the charging and discharging process of the battery cells, and determines the outlier battery cells that need to be charged according to the risk level of the battery cells after determining the risk level of the charging and discharging voltages and the pressure difference of the battery cells through comparison with the comparison interval. Thus, the online analysis and determination of the outlier battery cells can be realized without manual processing, which not only improves the timeliness of the analysis and processing of the outlier battery cells that need to be charged compared with manual processing, but also improves the accuracy and reliability of the analysis and processing of the outlier battery cells that need to be charged through automatic operation processing based on data, which has good practicality.

[0113] Embodiment Three

[0114] The present embodiment relates to a big data platform, which is connected to a battery pack of a new energy vehicle or an energy storage system, i.e., in the battery pack of the new energy vehicle or the energy storage system, a battery management system and other control devices for detecting the battery pack and even the whole vehicle or the whole energy storage system are connected to the big data platform through the Internet of Things, and can transmit each related parameter information in the operation of the battery pack to the big data platform.

[0115] Meanwhile, the big data platform of the present embodiment is provided with a storage and an executor, and a computer program is stored in the storage, which can realize the analysis method of the outlier battery cells in Embodiment One when executed by the executor.

[0116] The memory of the present embodiment is arranged in the permanent and non-permanent, movable and non-movable media of the big data platform, which can realize the storage of information, i.e. computer program by any method or technology. Moreover, the examples of the 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, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tape, magnetic tape, disk storage or other magnetic storage devices, or any other non-transmission medium capable of storing information accessible by a computing device.

[0117] The big data platform of the present embodiment can timely, accurately and reliably screen out the outlier battery cell in the battery pack of the new energy vehicle or the energy storage system by executing the analysis method of the outlier battery cell in embodiment one, and can determine the power supply capacity of the outlier battery cell, which is beneficial to the processing of the battery cell consistency problem and has good practicability.

[0118] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for analyzing outlier battery cells, characterized in that, The analytical method includes: 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 of the battery cells. 压差i ; The processing unit (200) 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 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. The processing unit (200) 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 σ of all the cell voltage differences mentioned above. 压差 ; The 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 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; The processing unit (200) 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. 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.

2. The method for analyzing outlier cells according to claim 1, characterized in that: The charging voltage U of each of the aforementioned 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; 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.

3. The method for analyzing outlier cells according to claim 1, characterized in that: The range of the charging voltage comparison interval is: The range of the discharge voltage comparison interval is: The range of the pressure difference comparison interval is: 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 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. 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. 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. 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 any one of claims 1 to 5, characterized in that, 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 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 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.

7. The method for analyzing outlier cells according to claim 6, characterized in that: The charge-replenishing capacity of the out-of-group battery cell is the charge 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.

8. 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 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 ; The first calculation module (20) is used to calculate 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 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. The second calculation module (30) 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 σx of the discharge voltage of all the cells and the standard deviation σ of the voltage difference of all the cells 压差 ; The first determining module (40) 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; The second determining module (50) 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. 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.

9. The analysis apparatus for outlier cells according to claim 8, characterized in that: 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, within 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.

10. 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 7.

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