Battery System Cell Consistency Evaluation Method, Control Device, and Storage Medium

Abstract

An embodiment of the present application provides a method for evaluating the consistency of battery system monomers, including the following steps: obtaining the working parameters of each stage during the first charge and discharge process of the battery system; after the first charge and discharge, obtaining the working parameters of each stage during at least one charge and discharge process of the battery system; determining the weight corresponding to each working parameter of each stage, and the sum of all the weights for each charge and discharge process is 100%; according to all the working parameters of all stages during each charge and discharge process, all the working parameters of all stages during the first charge and discharge process, and the corresponding weights, an evaluation index for evaluating the consistency of battery system monomers corresponding to each charge and discharge process is obtained. By obtaining the working parameters and related weights of each stage of the battery system charge and discharge, the embodiment of the present application solves the problems of deviation in evaluating the consistency of battery system monomers by only relying on the test results of single cells in the past and the long time-consuming complex calculation in the past.

Description

Technical Field

[0001] This application relates to the field of new energy power batteries, and particularly to a method for evaluating the consistency of battery system monomers, a control device, and a storage medium. Background Art

[0002] Electric vehicles rely on battery systems to provide power for driving. The consistency of monomers in the battery system directly determines the available energy of the battery system, as well as the driving range and safety of electric vehicles. Therefore, it is extremely important to evaluate the consistency of battery monomers in the battery system. Accurately evaluating the consistency state of monomers in the battery system can timely replace aging battery cells, improve the lifespan of the battery system, and avoid safety problems in electric vehicles. Summary of the Invention

[0003] In view of this, embodiments of this application are expected to provide a method for evaluating the consistency of battery system monomers, a control device, and a storage medium to more accurately evaluate the consistency of monomers in the battery system.

[0004] Embodiments of this application provide a method for evaluating the consistency of battery system monomers, including:

[0005] Obtaining the working parameters of each stage in the first charge-discharge process of the battery system;

[0006] After the first charge-discharge, obtaining the working parameters of each stage in at least one charge-discharge process of the battery system;

[0007] Determining the weight corresponding to each working parameter of each stage, and the sum of all the weights in each charge-discharge process is 100%;

[0008] According to all the working parameters of all stages in each charge-discharge process, all the working parameters of all stages in the first charge-discharge process, and the corresponding weights, obtaining an evaluation index corresponding to each charge-discharge process for evaluating the consistency of battery system monomers;

[0009] Wherein, in each charge-discharge process, the number of stages is multiple, at least one of the stages is a charging stage, and at least one stage is a discharging stage.

[0010] In some embodiments, according to all working parameters of all stages in each charge-discharge process, all working parameters of all stages in the first charge-discharge process, and the corresponding weights, an evaluation index for evaluating the consistency of battery system monomers corresponding to each charge-discharge process is obtained, including: according to each working parameter of each stage in each charge-discharge process, each working parameter of each stage in the first charge-discharge process, and the corresponding weights, a sub-evaluation index corresponding to each working parameter of each stage in each charge-discharge process is obtained, and the evaluation index corresponding to each charge-discharge process is the sum of all sub-evaluation indexes of each charge-discharge process.

[0011] In some embodiments, each working parameter of each stage in each discharge process is a first working parameter, and the corresponding working parameter of the corresponding stage in the first charge-discharge process is a second working parameter. The ratio of the absolute value of the difference between the first working parameter and the second working parameter to the second working parameter is the evaluation component of the first working parameter, and the sub-evaluation index corresponding to the first working parameter is the product of the evaluation component of the first working parameter and the corresponding weight.

[0012] In some embodiments, the number of charging stages is multiple, and the charging rates corresponding to the charging stages decrease sequentially in the order of the charging stages.

[0013] In some embodiments, there are multiple working parameters corresponding to each stage. One of the working parameters is the voltage of the battery system, one of the working parameters is the capacity of the battery system, and one of the working parameters is the energy of the battery system.

[0014] In some embodiments, constant current discharge is adopted.

[0015] In some embodiments, the number of charging stages is multiple. One of the charging stages is the first charging stage, one of the charging stages is the second charging stage, and one of the charging stages is the third charging stage. The charging current of the third charging stage is less than the charging current of the second charging stage, and the charging current of the second charging stage is less than the charging current of the first charging stage. The calculation formula for the evaluation index corresponding to each charge-discharge process for evaluating the consistency of battery system monomers is:

[0016]

[0017] In the formula:

[0018] U1 is the charging voltage of the first charging stage corresponding to each charge-discharge of the battery system;

[0019] U2 is the charging voltage of the second charging stage corresponding to each charge-discharge of the battery system;

[0020] U3 is the charging voltage of the third charging stage corresponding to each charge and discharge of the battery system;

[0021] U4 is the discharging voltage corresponding to each charge and discharge of the battery system;

[0022] U01 is the charging voltage of the first charging stage corresponding to the first charge and discharge of the battery system;

[0023] U02 is the charging voltage of the second charging stage corresponding to the first charge and discharge of the battery system;

[0024] U03 is the charging voltage of the third charging stage corresponding to the first charge and discharge of the battery system;

[0025] U04 is the discharging voltage corresponding to the first charge and discharge of the battery system;

[0026] Q1 is the charging capacity of the first charging stage corresponding to each charge and discharge of the battery system;

[0027] Q2 is the charging capacity of the second charging stage corresponding to each charge and discharge of the battery system;

[0028] Q3 is the charging capacity of the third charging stage corresponding to each charge and discharge of the battery system;

[0029] Q4 is the discharging capacity corresponding to each charge and discharge of the battery system;

[0030] Q01 is the charging capacity of the first charging stage corresponding to the first charge and discharge of the battery system;

[0031] Q02 is the charging capacity of the second charging stage corresponding to the first charge and discharge of the battery system;

[0032] Q03 is the charging capacity of the third charging stage corresponding to the first charge and discharge of the battery system;

[0033] Q04 is the discharging capacity corresponding to the first charge and discharge of the battery system;

[0034] E1 is the charging energy of the first charging stage corresponding to each charge and discharge of the battery system;

[0035] E2 is the charging energy of the second charging stage corresponding to each charge and discharge of the battery system;

[0036] E3 is the charging energy of the third charging stage corresponding to each charge and discharge of the battery system;

[0037] E4 is the discharging energy corresponding to each charge and discharge of the battery system;

[0038] E01 is the charging energy of the first charging stage corresponding to the first charge and discharge of the battery system;

[0039] E02 is the charging energy of the second charging stage corresponding to the first charge and discharge of the battery system;

[0040] E03 is the charging energy of the third charging stage corresponding to the first charge and discharge of the battery system;

[0041] E04 is the discharge energy corresponding to the first charge and discharge of the battery system.

[0042] In some embodiments, the evaluation method further includes: determining the health state of the battery system according to the difference between the value 1 and the evaluation index.

[0043] An embodiment of the present application further provides a control device, including a memory and a processor. The memory stores executable instructions that can run on the processor, and when the processor executes the program, it implements the steps in any of the above methods.

[0044] An embodiment of the present application further provides a computer storage medium, storing executable instructions, and the executable instructions are used to be executed by the processor to implement the steps in any of the above methods.

[0045] The battery system cell consistency evaluation method provided by the embodiments of the present application obtains the working parameters and related weights of each stage of charge and discharge of the battery system, and conducts a cell consistency evaluation on the overall battery system, solving the problem of deviation in evaluating the cell consistency of the battery system only relying on the test results of individual cells in the past, and avoiding the problems of long time consumption and large resource consumption in complex calculations in the past. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic flowchart of a battery system cell consistency evaluation method provided by an embodiment of the present application.

[0047] Figure 2 It is a schematic flowchart of a battery system cell consistency evaluation method provided by another embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. The detailed description in the specific embodiments should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation of the present application.

[0049] The following further describes the present application in detail with reference to the accompanying drawings and specific embodiments. The terms "first / second" involved in the embodiments of the present application are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second" can be interchanged with a specific order or sequence when permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In the description of the embodiments of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0050] In the related art, the evaluation of the consistency between the individual battery cells in a battery system is achieved by calculating the mean, variance, and coefficient of variation among the voltages of the individual battery cells. However, since only the individual battery cells that make up the battery system are tested, there are factors that the individual battery cells in different states have a greater impact on the consistency result, and there are also problems of complex calculation, long time consumption, and large resource consumption.

[0051] The embodiments of the present application provide a method for evaluating the consistency of individual battery cells in a battery system, including:

[0052] S1: Obtain the working parameters of each stage during the first charge and discharge process of the battery system.

[0053] S2: After the first charge and discharge, obtain the working parameters of each stage during at least one charge and discharge process of the battery system.

[0054] S3: Determine the weight corresponding to each working parameter of each stage, and the sum of all weights for each charge and discharge process is 100%.

[0055] S4: According to all the working parameters of all stages during each charge and discharge process, all the working parameters of all stages during the first charge and discharge process, and the corresponding weights, obtain the evaluation index for evaluating the consistency of individual battery cells in the battery system corresponding to each charge and discharge process.

[0056] It should be noted that during each charge and discharge process, the number of stages is multiple, at least one stage is a charging stage, and at least one stage is a discharging stage.

[0057] It should be noted that the individual battery cells in the battery system refer to the individual battery cells that make up the battery system.

[0058] The method for evaluating the consistency of individual battery cells in the embodiments of the present application evaluates the consistency of individual battery cells of the entire battery system by obtaining the working parameters and related weights of each stage of the charge and discharge of the battery system, solves the problem of deviation in evaluating the consistency of individual battery cells in the battery system only relying on the test results of individual battery cells in the past, and avoids the problems of complex calculation, long time consumption, and large resource consumption in the past.

[0059] Exemplarily, according to all working parameters of all stages in each charge-discharge process, all working parameters of all stages in the first charge-discharge process, and corresponding weights, an evaluation index for evaluating the consistency of each battery system cell is obtained, including: according to each working parameter of each stage in each charge-discharge process, each working parameter of each stage in the first charge-discharge process, and corresponding weights, a sub-evaluation index corresponding to each working parameter of each stage in each charge-discharge process is obtained, and the evaluation index corresponding to each charge-discharge process is the sum of all sub-evaluation indexes of each charge-discharge process.

[0060] In this embodiment, by comprehensively considering the working parameters and corresponding weights under various working conditions in the battery system, accurate sub-evaluation indexes are obtained, and then according to each sub-evaluation index, an evaluation index during the working process of the battery system is obtained, improving the accuracy of the evaluation.

[0061] Exemplarily, each working parameter of each stage in each discharge process is a first working parameter, the corresponding working parameter of the corresponding stage in the first charge-discharge process is a second working parameter, the ratio of the absolute value of the difference between the first working parameter and the second working parameter to the second working parameter is the evaluation component of the first working parameter, and the sub-evaluation index corresponding to the first working parameter is the product of the evaluation component of the first working parameter and the corresponding weight.

[0062] In this embodiment, through the calculation among the first working parameter, the second working parameter, and the corresponding weight, not only the differences between the first charge-discharge of the battery system and each subsequent charge-discharge are comprehensively considered, but also the weights are set by weighing the influence of each working parameter on the evaluation result, further improving the accuracy of the evaluation result.

[0063] It should be noted that the charging process can be constant-current charging or variable-current multi-stage charging, that is, the charging process is divided into multiple stages according to the number of times of variable current. There is only one charging stage in constant-current charging, and in variable-current multi-stage charging, the current is the same in a single stage.

[0064] Exemplarily, the number of charging stages is multiple, and the charging rates corresponding to the charging stages decrease in sequence according to the order of the charging stages.

[0065] Since the charging rate is equal to the charging current divided by the battery capacity, in the battery system test, as the charging stage of the battery system increases, the charging current decreases in sequence.

[0066] In this embodiment, compared with constant-current charging, the method of adopting multi-stage charging with a higher charging rate in the earlier stage than in the later stage is convenient for the battery system to obtain a larger amount of electricity.

[0067] Exemplarily, there are multiple operating parameters corresponding to each stage. One of the operating parameters is the voltage of the battery system, one of the operating parameters is the capacity of the battery system, and one of the operating parameters is the energy of the battery system.

[0068] It should be noted that according to the charge and discharge process of the battery system, in the charging stage, the voltage of the battery system is the charging voltage of the battery system, the capacity of the battery system is the charging capacity of the battery system, and the energy of the battery system is the charging energy of the battery system. In the discharging stage, the voltage of the battery system is the discharging voltage of the battery system, the capacity of the battery system is the discharging capacity of the battery system, and the energy of the battery system is the discharging energy of the battery system. In this embodiment, multiple parameters such as the charging voltage, charging capacity, charging energy, discharging voltage, discharging capacity, and discharging energy are obtained. Since the more indicators are obtained, the better the working condition of the battery system can be comprehensively reflected, the accuracy of the evaluation of the cell consistency of the battery system can be further improved.

[0069] In some embodiments, only the parameters of the charging voltage, charging capacity, discharging voltage, and discharging capacity may be obtained, but the weights corresponding to the above parameters need to be changed accordingly to ensure that the sum of all weights in each charge and discharge process is 100%.

[0070] It should be noted that the sum of all weights is 100%, but the value of each specific weight is not limited. The numerical range of the weights needs to be adjusted in combination with the type of single cells in the battery system in practice and the importance in the charge and discharge process.

[0071] Exemplarily, the battery system discharges at a constant current.

[0072] It should be noted that there is only one discharging stage for constant current discharge.

[0073] In this embodiment, the battery system adopts a constant current discharge mode, which is convenient for monitoring and obtaining various parameters such as the discharging voltage and discharging capacity during the discharging process.

[0074] The current for the constant current discharge of the battery system is not limited. In some embodiments, the battery system discharges at 1C (the battery charge and discharge capacity ratio), that is, the discharging capacity of the battery system is discharged in 1 hour. In other embodiments, the battery system discharges at 0.5C.

[0075] Exemplarily, the number of charging stages is multiple. One of the charging stages is the first charging stage, one of the charging stages is the second charging stage, one of the charging stages is the third charging stage. The charging current in the third charging stage is less than the charging current in the second charging stage, and the charging current in the second charging stage is less than the charging current in the first charging stage. The calculation formula for the evaluation index used to evaluate the cell consistency of the battery system corresponding to each charge and discharge process is:

[0076]

[0077] Wherein:

[0078] U1 is the charging voltage of the first charging stage corresponding to each charge and discharge of the battery system;

[0079] U2 is the charging voltage of the second charging stage corresponding to each charge and discharge of the battery system;

[0080] U3 is the charging voltage of the third charging stage corresponding to each charge and discharge of the battery system;

[0081] U4 is the discharging voltage corresponding to each charge and discharge of the battery system;

[0082] U01 is the charging voltage of the first charging stage corresponding to the first charge and discharge of the battery system;

[0083] U02 is the charging voltage of the second charging stage corresponding to the first charge and discharge of the battery system;

[0084] U03 is the charging voltage of the third charging stage corresponding to the first charge and discharge of the battery system;

[0085] U04 is the discharging voltage corresponding to the first charge and discharge of the battery system;

[0086] Q1 is the charging capacity of the first charging stage corresponding to each charge and discharge of the battery system;

[0087] Q2 is the charging capacity of the second charging stage corresponding to each charge and discharge of the battery system;

[0088] Q3 is the charging capacity of the third charging stage corresponding to each charge and discharge of the battery system;

[0089] Q4 is the discharging capacity corresponding to each charge and discharge of the battery system;

[0090] Q01 is the charging capacity of the first charging stage corresponding to the first charge and discharge of the battery system;

[0091] Q02 is the charging capacity of the second charging stage corresponding to the first charge and discharge of the battery system;

[0092] Q03 is the charging capacity of the third charging stage corresponding to the first charge and discharge of the battery system;

[0093] Q04 is the discharging capacity corresponding to the first charge and discharge of the battery system;

[0094] E1 is the charging energy of the first charging stage corresponding to each charge and discharge of the battery system;

[0095] E2 is the charging energy of the second charging stage corresponding to each charge and discharge of the battery system;

[0096] E3 is the charging energy of the third charging stage corresponding to each charge and discharge of the battery system;

[0097] E4 is the discharge energy corresponding to each charge and discharge of the battery system;

[0098] E01 is the charging energy of the first charging stage corresponding to the first charge and discharge of the battery system;

[0099] E02 is the charging energy of the second charging stage corresponding to the first charge and discharge of the battery system;

[0100] E03 is the charging energy of the third charging stage corresponding to the first charge and discharge of the battery system;

[0101] E04 is the discharge energy corresponding to the first charge and discharge of the battery system.

[0102] Exemplarily, the evaluation method further includes: determining the health state of the battery system according to the difference between the value 1 and the evaluation index.

[0103] In this embodiment, the SOH (State of Health, the health state of the battery, 100% for a newly manufactured battery and 0% for a completely scrapped battery) of the battery system is determined by the evaluation index for evaluating the consistency of battery system monomers, which can represent the ratio of the performance parameters of the battery system to the nominal parameters after being used for a period of time, and reflect the current aging situation of the battery system.

[0104] The second aspect of the embodiments of the present application provides a control device, including a memory and a processor. The memory stores executable instructions that can run on the processor, and when the processor executes the program, it implements the steps in any one of the above methods.

[0105] The third aspect of the embodiments of the present application provides a storage medium storing executable instructions for being executed by a processor to implement the steps in any one of the above methods.

[0106] The following describes a specific embodiment of the present application. Please refer to Figure 2 .

[0107] S1.1. Obtain the working parameters of each stage in the first charge and discharge process of the battery system. The charging adopts three-stage charging, and the charging rate corresponding to the charging stage decreases sequentially in the order of the charging stages. Among them, the current in the first charging stage is I1, the current in the second charging stage is I2, and the current in the third charging stage is I3, and I3 < I2 < I1. The battery system discharges at a constant current of 1C, and the specific values of each parameter are shown in Table 1.

[0108] Stage Battery voltage / V (Volts) Capacity / Ah (Ampere-hours) Energy / Wh (Watt-hours) I1 Charging U01 Q01 E01 I2 Charging (<I1) U02 Q02 E02 I3 Charging (<I2) U03 Q03 E03 I4 Discharging U04 Q04 E04

[0109] Table 1

[0110] S1.2. After the first charge and discharge, obtain the operating parameters of the battery system at each stage during at least one charge and discharge process. The charging adopts three-stage charging, and the charging rate corresponding to each charging stage decreases sequentially according to the order of the charging stages. The battery system discharges at a constant current of 1C. For the specific values of each parameter, see Table 2.

[0111] Stage Battery voltage / V (Volts) Capacity / Ah (Ampere-hours) Energy / Wh (Watt-hours) I1 Charging U1 Q1 E1 I2 Charging (<I1) U2 Q2 E2 I3 Charging (<I2) U3 Q3 E3 I4 Discharging U4 Q4 E4

[0112] Table 2

[0113] S1.3. Determine the weight corresponding to each operating parameter at each stage. The sum of all weights for each charge and discharge process is 100%. For the specific values of each weight, see Table 3.

[0114] Impact factor Numerical range A 10％ B 3％ C 1％ D 10％ E 15％ F 3％ G 5％ H 15％ I 15％ J 3％ K 5％ L 15％

[0115] Table 3

[0116] S1.4. According to the formula: Calculate the evaluation index of the cell consistency of the battery system.

[0117] S1.5. Evaluate the consistency index of the battery system according to Table 4.

[0118] It should be noted that the larger the value of the evaluation index W, the worse the consistency of the cells in the battery system.

[0119]

[0120]

[0121] Table 4 S1.6. Determine the health state of the battery system according to the difference between the value 1 and the evaluation index. For details, see Table 5.

[0122] Number of cycles W value SOH 1 0％ 100％ 2 1％ 99％ … … … 1500 25％ 75％

[0123] Table 5

[0124] The number of cycles of the charge and discharge test of the battery system is not limited and should be determined according to the specific model of the battery system. In some embodiments, the number of charge and discharge cycles is 1500 times.

[0125] The SOH value of the battery system is not limited and should be determined according to the requirements of the manufacturer in practice. In some embodiments, the lower limit value of the SOH of the battery system is 75%, that is, when the lower limit value of the SOH of the battery system is 75%, the charge and discharge test is terminated.

[0126] As described above, it is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application are all included within the protection scope of the present application.

Claims

1. A method for evaluating the consistency of battery system monomers, characterized in that, including: Obtaining the operating parameters of each stage during the first charge-discharge process of the battery system; After the first charge-discharge, obtaining the operating parameters of each stage during at least one charge-discharge process of the battery system; Determining the weight corresponding to each operating parameter of each stage, and the sum of all the weights for each charge-discharge process is 100%; Based on all the operating parameters of all stages during each charge-discharge process, all the operating parameters of all stages during the first charge-discharge process, and the corresponding weights, obtaining an evaluation index corresponding to each charge-discharge process for evaluating the consistency of battery system cells; Wherein, during each charge-discharge process, the number of stages is multiple, at least one of the stages is a charging stage, and at least one stage is a discharging stage; The number of the charging stages is multiple, one of the charging stages is the first charging stage, one of the charging stages is the second charging stage, one of the charging stages is the third charging stage, the charging current of the third charging stage is less than the charging current of the second charging stage, the charging current of the second charging stage is less than the charging current of the first charging stage, and the calculation formula for the evaluation index corresponding to each charge-discharge process for evaluating the consistency of battery system cells is: In the formula: U1 is the charging voltage of the first charging stage corresponding to each charge-discharge of the battery system; U2 is the charging voltage of the second charging stage corresponding to each charge-discharge of the battery system; U3 is the charging voltage of the third charging stage corresponding to each charge-discharge of the battery system; U4 is the discharging voltage corresponding to each charge-discharge of the battery system; U01 is the charging voltage of the first charging stage corresponding to the first charge-discharge of the battery system; U02 is the charging voltage of the second charging stage corresponding to the first charge-discharge of the battery system; U03 is the charging voltage of the third charging stage corresponding to the first charge-discharge of the battery system; U04 is the discharging voltage corresponding to the first charge-discharge of the battery system; Q1 is the charging capacity of the first charging stage corresponding to each charge-discharge of the battery system; Q2 is the charging capacity of the second charging stage corresponding to each charge-discharge of the battery system; Q3 is the charging capacity of the third charging stage corresponding to each charge-discharge of the battery system; Q4 is the discharging capacity corresponding to each charge-discharge of the battery system; Q01 is the charging capacity of the first charging stage corresponding to the first charge-discharge of the battery system; Q02 is the charging capacity of the second charging stage corresponding to the first charge-discharge of the battery system; Q03 is the charging capacity of the third charging stage corresponding to the first charge-discharge of the battery system; Q04 is the discharging capacity corresponding to the first charge-discharge of the battery system; E1 is the charging energy of the first charging stage corresponding to each charge-discharge of the battery system; E2 is the charging energy of the second charging stage corresponding to each charge-discharge of the battery system; E3 is the charging energy of the third charging stage corresponding to each charge-discharge of the battery system; E4 is the discharging energy corresponding to each charge-discharge of the battery system; E01 is the charging energy of the first charging stage corresponding to the first charge-discharge of the battery system; E02 is the charging energy of the second charging stage corresponding to the first charge-discharge of the battery system; E03 is the charging energy of the third charging stage corresponding to the first charge and discharge of the battery system; E04 is the discharge energy corresponding to the first charge and discharge of the battery system; W is an evaluation index for evaluating the consistency of battery system cells; A is the weight corresponding to the charging voltage of the first charging stage for each charge and discharge of the battery system; B is the weight corresponding to the charging voltage of the second charging stage for each charge and discharge of the battery system; C is the weight corresponding to the charging voltage of the third charging stage for each charge and discharge of the battery system; D is the weight corresponding to the discharge voltage for each charge and discharge of the battery system; E is the weight corresponding to the charging capacity of the first charging stage for each charge and discharge of the battery system; F is the weight corresponding to the charging capacity of the second charging stage for each charge and discharge of the battery system; G is the weight corresponding to the charging capacity of the third charging stage for each charge and discharge of the battery system; H is the weight corresponding to the discharge capacity for each charge and discharge of the battery system; I is the weight corresponding to the charging energy of the first charging stage for each charge and discharge of the battery system; J is the weight corresponding to the charging energy of the second charging stage for each charge and discharge of the battery system; K is the weight corresponding to the charging energy of the third charging stage for each charge and discharge of the battery system; L is the weight corresponding to the discharge energy for each charge and discharge of the battery system.

2. The battery system cell consistency evaluation method according to claim 1, wherein Based on all working parameters of all stages during each charge and discharge process, all working parameters of all stages during the first charge and discharge process, and the corresponding weights, an evaluation index for evaluating the consistency of battery system cells corresponding to each charge and discharge process is obtained, including: based on each working parameter of each stage during each charge and discharge process, each working parameter of each stage during the first charge and discharge process, and the corresponding weights, a sub-evaluation index corresponding to each working parameter of each stage during each charge and discharge process is obtained, and the evaluation index corresponding to each charge and discharge process is the sum of all sub-evaluation indexes of each charge and discharge process.

3. The battery system cell consistency evaluation method according to claim 2, wherein Each working parameter of each stage during each discharge process is the first working parameter, and the corresponding working parameter of the corresponding stage during the first charge and discharge process is the second working parameter. The ratio of the absolute value of the difference between the first working parameter and the second working parameter to the second working parameter is the evaluation component of the first working parameter, and the sub-evaluation index corresponding to the first working parameter is the product of the evaluation component of the first working parameter and the corresponding weight.

4. The method for evaluating the consistency of battery system monomers according to any one of claims 1 to 3, characterized in that The number of charging stages is multiple, and the charging rate corresponding to the charging stages decreases sequentially in the order of the charging stages.

5. The method for evaluating the consistency of battery system monomers according to any one of claims 1 to 3, characterized in that The working parameters corresponding to each stage are multiple, one of the working parameters is the voltage of the battery system, one of the working parameters is the capacity of the battery system, and one of the working parameters is the energy of the battery system.

6. The battery system cell consistency evaluation method according to any one of claims 1 to 3, characterized in that Constant current discharge is adopted.

7. The method for evaluating the consistency of battery system monomers according to any one of claims 1 to 3, characterized in that, The evaluation method further includes: determining the health state of the battery system according to the difference between the value 1 and the evaluation index.

8. A control device, characterized in that, It includes a memory and a processor. The memory stores executable instructions that can run on the processor, and when the processor executes the program, it implements the steps in the method according to any one of claims 1 to 7.

9. A storage medium, characterized in that, Stores executable instructions, the executable instructions being for execution by a processor to implement the steps in the method according to any one of claims 1 to 7.

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