Method, device, storage medium and electronic device for determining available capacity of battery cluster

Abstract

The present application relates to a method, device, storage medium and electronic device for determining the available capacity of a battery cluster. The method comprises: determining the rated available capacity in the battery cluster; adjusting the rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the temperature correction coefficient is calculated by a first two-dimensional table, and the charge consistency coefficient is calculated by querying the terminal voltage difference of each single cell in the sample battery cluster and the reference cell of the sample battery cluster to obtain the state of charge difference from a second two-dimensional table; determining the adjusted capacity as the real-time available capacity of the battery cluster. The present application solves the technical problem that the real-time available capacity of a battery cluster is difficult to determine.

Description

Technical Field

[0001] The present application relates to the field of battery clusters, and in particular to a method, device, storage medium and electronic device for determining the available capacity of a battery cluster. Background Art

[0002] In the prior art, for a battery cluster composed of multiple battery cells, the internal structure of the battery cells is complex, the electrochemical reaction process and reaction stages are complex and difficult to determine, and the actual application conditions of the battery cluster are harsh and changeable, making it difficult to determine the real-time available capacity of the battery cluster, and further making it difficult to determine the actual state of charge. Summary of the invention

[0003] The present application provides a method, device, storage medium and electronic device for determining the available capacity of a battery cluster, so as to solve the technical problem that it is difficult to determine the real-time available capacity of a battery cluster.

[0004] In a first aspect, the present application provides a method for determining the available capacity of a battery cluster, comprising: determining the rated available capacity in the battery cluster; adjusting the rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the temperature correction coefficient is calculated by a first two-dimensional table, the first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the charge consistency coefficient is calculated by querying a second two-dimensional table for the state of charge difference obtained by the terminal voltage difference between each single cell in the sample battery cluster and a reference cell of the sample battery cluster, the second two-dimensional table records the correspondence between the terminal voltage and the state of charge of each single cell in the sample battery cluster at different temperatures, and the life attenuation coefficient is calculated based on the life attenuation data of the sample battery cluster; and determining the adjusted capacity as the real-time available capacity of the battery cluster.

[0005] In a second aspect, the present application provides a device for determining the available capacity of a battery cluster, comprising: a first determination module, used to determine the rated available capacity in the above-mentioned battery cluster; an adjustment module, used to adjust the above-mentioned rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the above-mentioned temperature correction coefficient is calculated by a first two-dimensional table, the above-mentioned first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the above-mentioned charge consistency coefficient is calculated by querying the state of charge difference obtained by querying the second two-dimensional table based on the terminal voltage difference between each single cell in the above-mentioned sample battery cluster and the reference cell of the above-mentioned sample battery cluster, the above-mentioned second two-dimensional table records the correspondence between the terminal voltage and the state of charge of each single cell in the above-mentioned sample battery cluster at different temperatures, and the above-mentioned life attenuation coefficient is calculated based on the life attenuation data of the above-mentioned sample battery cluster; the second determination module is used to determine the above-mentioned adjusted capacity as the real-time available capacity of the above-mentioned battery cluster.

[0006] As an optional example, the adjustment module includes: an adjustment unit, used to multiply the rated available capacity by at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient in sequence to obtain an adjusted capacity.

[0007] As an optional example, the above-mentioned device also includes: a first processing module, which is used to obtain the cell capacity of each single cell in the above-mentioned sample battery cluster under different temperatures and different current rates before adjusting at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient of the above-mentioned rated available capacity to obtain the adjusted capacity; determine the average cell capacity of each single cell as the cell capacity of the benchmark cell; determine the cell capacity of each single cell in the above-mentioned sample battery cluster at different temperatures and different current rates and the cell capacity of the benchmark cell as the above-mentioned first two-dimensional table.

[0008] As an optional example, the adjustment module includes: a first calculation unit, configured to determine the temperature correction coefficient by the following formula:

[0009] (1)

[0010] in, To query the first two-dimensional table to obtain the table capacity of the reference cell of the battery cluster at the current temperature and current current rate of the battery cluster, The calibration capacity is obtained by linearly interpolating the table capacity of the reference cell of the battery cluster at different current rates at the current temperature. The sum of the two is the actual capacity of the battery cluster at the current temperature. initis the rated capacity of the above battery cluster, is the temperature correction coefficient mentioned above.

[0011] As an optional example, the above-mentioned device also includes: a second processing module, which is used to obtain the terminal voltage of each single cell in different charge states of the above-mentioned sample battery cluster at different temperatures before adjusting at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient of the above-mentioned rated available capacity to obtain the adjusted capacity; determine the average of the terminal voltages of each single cell in different charge states as the terminal voltage of the reference cell in different charge states of the above-mentioned sample battery cluster; determine the terminal voltage of each single cell in the above-mentioned sample battery cluster at different temperatures and different charge states and the terminal voltage of the reference cell at different temperatures and different charge states as the above-mentioned second two-dimensional table.

[0012] As an optional example, the adjustment module includes: a second calculation unit, configured to determine the charging consistency coefficient by the following formula:

[0013] (2)

[0014] Among them, SOC max and SOC min are the maximum and minimum values ​​of the difference between the state of charge of the single cells in the battery cluster and the state of charge of the reference cell, is the charge consistency coefficient mentioned above.

[0015] As an optional example, the first two-dimensional table and the second two-dimensional table include a charging two-dimensional table in a charging state and a discharging two-dimensional table in a discharging state.

[0016] In a third aspect, the present application provides an electronic device comprising: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor connected to the at least one bus; and at least one memory connected to the at least one bus, wherein the memory stores a computer program, and the processor is configured to implement any one of the above-mentioned methods for determining the available capacity of a battery cluster when executing the computer program.

[0017] In a fourth aspect, the present application further provides a computer storage medium storing computer executable instructions, wherein the computer executable instructions are used to execute any of the above methods for determining the available capacity of a battery cluster in the present application.

[0018] The above technical solution provided by the embodiment of the present application has the following advantages over the prior art: the solution provided by the embodiment of the present application, by determining the rated available capacity in the above battery cluster; adjusting the above rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the above temperature correction coefficient is calculated by a first two-dimensional table, the above first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the above charge consistency coefficient is calculated by querying the state of charge difference obtained by querying the second two-dimensional table based on the terminal voltage difference between each single cell in the above sample battery cluster and the reference cell of the above sample battery cluster, the above second two-dimensional table records the corresponding relationship between the terminal voltage and the state of charge of each single cell in the above sample battery cluster at different temperatures, and the above life attenuation coefficient is calculated based on the life attenuation data of the above sample battery cluster; the above adjusted capacity is determined as the real-time available capacity of the above battery cluster, thereby improving the accuracy of determining the real-time available capacity of the battery cluster, and then determining the actual state of charge according to the real-time available capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0022] Figure 1 A flowchart of a method for determining the available capacity of a battery cluster provided in an embodiment of the present application;

[0023] Figure 2 A flow chart of another method for determining the available capacity of a battery cluster provided in an embodiment of the present application;

[0024] Figure 3 A flowchart of another method for determining the available capacity of a battery cluster provided in an embodiment of the present application;

[0025] Figure 4A model structure diagram of a method for determining the available capacity of a battery cluster provided in an embodiment of the present application;

[0026] Figure 5 A schematic diagram of the structure of a device for determining the available capacity of a battery cluster provided in an embodiment of the present application;

[0027] Figure 6 A schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0030] In order to solve the technical problem in the prior art that the real-time available capacity of a battery cluster is difficult to determine, the present application provides a method for determining the available capacity of a battery cluster, which can achieve the effect of improving the accuracy of determining the real-time available capacity of the battery cluster.

[0031] Figure 1 The present invention provides a flowchart of a method for determining the available capacity of a battery cluster according to an embodiment of the present invention. Figure 1 As shown, the method for determining the available capacity of the battery cluster includes:

[0032] S102, determining the rated available capacity of the battery cluster;

[0033] S104, adjusting the rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the temperature correction coefficient is calculated by a first two-dimensional table, the first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the charge consistency coefficient is calculated by querying a second two-dimensional table for a state of charge difference between the terminal voltage difference of each single cell in the sample battery cluster and a reference cell of the sample battery cluster, the second two-dimensional table records a corresponding relationship between the terminal voltage and the state of charge of each single cell in the sample battery cluster at different temperatures, and the life attenuation coefficient is calculated based on the life attenuation data of the sample battery cluster;

[0034] S106: Determine the adjusted capacity as the real-time available capacity of the battery cluster.

[0035] In this embodiment, the above-mentioned method for determining the available capacity of a battery cluster can be applied in the process of determining the available capacity of a battery cluster. A battery cluster is a combination of batteries obtained by connecting multiple battery (battery cell) monomers in series or in parallel or in series and parallel. For example, three batteries are connected in series to form a battery cluster. A battery monomer is a battery. The battery cluster includes a rated available capacity, which can be a measured or estimated capacity, or the initial available capacity of the battery cluster after production.

[0036] The real-time available capacity of the battery cluster will fluctuate with the use of the battery cluster, ambient temperature, etc. In order to measure the accurate real-time available capacity, this embodiment proposes to use at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient to adjust the rated available capacity, so as to obtain the adjusted rated available capacity. The adjusted rated available capacity is regarded as the real-time available capacity of the battery cluster.

[0037] In this embodiment, when at least one of the temperature correction coefficient, the charge consistency coefficient, and the life attenuation coefficient is used to adjust the rated available capacity, if one of the coefficients is used to adjust the rated available capacity, the rated available capacity is directly multiplied by the coefficient; if multiple coefficients are used to adjust the rated available capacity, the rated available capacity is multiplied by each coefficient in turn, and the result is used as the real-time available capacity. In the following example, the temperature correction coefficient, the charge consistency coefficient, and the life attenuation coefficient are used to adjust the rated available capacity together, which does not constitute a unique limitation of this embodiment.

[0038] The temperature correction coefficient is calculated by a first two-dimensional table, which records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates.

[0039] The charge consistency coefficient is calculated by querying a second two-dimensional table to obtain the charge state difference based on the terminal voltage difference between each single cell in the sample battery cluster and the reference cell of the sample battery cluster. The second two-dimensional table records the corresponding relationship between the terminal voltage and the charge state of each single cell in the sample battery cluster at different temperatures.

[0040] The above life attenuation coefficient is calculated based on the life attenuation data of the above sample battery cluster. The life attenuation of the sample battery cluster as it is used can be viewed through historical data. The life attenuation directly affects the real-time available capacity. The life attenuation coefficient is calculated based on the life attenuation data.

[0041] The above-mentioned sample battery cluster is a battery cluster for testing used in the process of determining the first two-dimensional table and the second two-dimensional table. For example, battery cells from the same batch can be regarded as battery cells with similar properties, and some of the battery cells are combined into a battery cluster. The battery cluster is used as a sample battery cluster to construct the first two-dimensional table and the second two-dimensional table. The constructed two-dimensional table can be used to determine the temperature correction coefficient and charge consistency coefficient of other battery clusters formed by combining battery cells from the same batch.

[0042] The solution provided by the embodiment of the present application determines the rated available capacity in the above-mentioned battery cluster; adjusts the above-mentioned rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the above-mentioned temperature correction coefficient is calculated by a first two-dimensional table, the above-mentioned first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the above-mentioned charge consistency coefficient is calculated by querying the state of charge difference obtained by querying the second two-dimensional table based on the terminal voltage difference between each single cell in the above-mentioned sample battery cluster and the reference cell of the above-mentioned sample battery cluster, the above-mentioned second two-dimensional table records the corresponding relationship between the terminal voltage and the state of charge of each single cell in the above-mentioned sample battery cluster at different temperatures, and the above-mentioned life attenuation coefficient is calculated according to the life attenuation data of the above-mentioned sample battery cluster; the above-mentioned adjusted capacity is determined as the real-time available capacity of the above-mentioned battery cluster, thereby improving the determination accuracy of the real-time available capacity of the battery cluster, and then determining the actual state of charge according to the real-time available capacity.

[0043] In this embodiment, the first two-dimensional table and the second two-dimensional table can be determined in advance through a sample battery cluster, and then, when the real-time available capacity of the battery cluster is calculated, the temperature correction coefficient and the charge consistency coefficient are determined through the first two-dimensional table and the second two-dimensional table, and then the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient are used to adjust the battery cluster to obtain the real-time available capacity of the battery cluster.

[0044] In one example, determining the first two-dimensional table may be as follows: Figure 2 Before adjusting at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient of the rated available capacity to obtain the adjusted capacity, the method includes:

[0045] S202, obtaining the cell capacity of each single cell of the sample battery cluster at different temperatures and different current rates;

[0046] S204 determines the average value of the cell capacity of each single cell as the cell capacity of the reference cell;

[0047] S206 , determining the cell capacity of each single cell in the sample battery cluster at different temperatures and different current rates and the cell capacity of the reference cell as the first two-dimensional table.

[0048] In the embodiment of constructing the first two-dimensional table provided in this embodiment, the first two-dimensional table records the cell capacity of each battery cell of the sample battery cluster under different temperatures and different current rates. The data of different temperatures can constitute different first two-dimensional tables. In addition, the first two-dimensional table can also be divided into a charging two-dimensional table and a discharging two-dimensional table, that is, at a certain temperature, when charging, the cell capacity of each battery cell monomer at different charging rates, and at a certain temperature, when discharging, the cell capacity of each battery cell monomer at different charging rates. The data obtained is the cell capacity of each battery cell at different rates at this temperature when charging and discharging. When actually calculating the real-time available capacity of the battery cluster, the corresponding first two-dimensional table is selected according to the actual temperature and charging and discharging scenario. The average value of the cell capacity of multiple battery cells in the battery cluster at a certain temperature, a certain current rate, and a charging or discharging scenario is the cell capacity of the reference cell at this temperature, the current rate, and the charging or discharging scenario. By testing and recording data on the sample battery cluster, the cell capacity of each battery cell of the sample battery cluster at different temperatures, charging and discharging scenarios, and different current rates is obtained. Based on the cell capacity, the cell capacity of the reference cell can be calculated to obtain a first two-dimensional table.

[0049] In an example, after the first two-dimensional table is determined, the temperature correction coefficient may be determined according to the first two-dimensional table. Specifically, the temperature correction coefficient may be determined according to formula (1).

[0050] (1)

[0051] in, To query the first two-dimensional table to obtain the table capacity of the reference cell of the battery cluster at the current temperature and current current rate of the battery cluster, The calibration capacity is obtained by linearly interpolating the table capacity of the reference cell of the battery cluster at different current rates at the current temperature. The sum of the two is the actual capacity of the battery cluster at the current temperature. init is the rated capacity of the above battery cluster, is the temperature correction coefficient mentioned above.

[0052] That is, for the battery cluster whose real-time available capacity is to be measured, the current temperature and whether it is a charging or discharging scenario are determined, and the corresponding first two-dimensional table is selected. Then, in the first two-dimensional table, the cell capacity of each battery cell in the battery cluster is obtained, and the cell capacity of the reference cell is calculated. The cell capacity of the reference cell is substituted into formula (1), and the result is used as the temperature correction coefficient.

[0053] In one example, determining the second two-dimensional table may be as follows: Figure 3 As shown, before adjusting at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient of the rated available capacity to obtain the adjusted capacity, the method includes:

[0054] S302, obtaining the terminal voltage of each single cell of the sample battery cluster at different temperatures and different states of charge;

[0055] S304, determining the average of the terminal voltages of each single cell at different states of charge as the terminal voltages of the reference cells at different states of charge of the sample battery cluster;

[0056] S306 , determining the terminal voltage of each single cell in the sample battery cluster at different temperatures and different states of charge and the terminal voltage of the reference cell at different temperatures and different states of charge as the second two-dimensional table.

[0057] In the embodiment of constructing the second two-dimensional table provided in this embodiment, the second two-dimensional table records the terminal voltage of each battery cell in the sample battery cluster at different temperatures and at different states of charge. The data of different temperatures can constitute different second two-dimensional tables. In addition, the second two-dimensional table can also be divided into a charging two-dimensional table and a discharging two-dimensional table, that is, at a certain temperature, when charging, the terminal voltage of each battery cell at different states of charge, and at a certain temperature, when discharging, the terminal voltage of each battery cell at different states of charge. The data obtained is the terminal voltage of each battery cell at different states of charge at this temperature during charging and discharging. When actually calculating the real-time available capacity of the battery cluster, the corresponding second two-dimensional table is selected according to the actual temperature and charging and discharging scenario. The average value of the terminal voltages of multiple battery cells in the battery cluster at a certain temperature, a certain state of charge, and a charging or discharging scenario is the terminal voltage of the reference cell at this temperature, this state of charge, and the charging or discharging scenario. By testing and recording data on the sample battery cluster, the terminal voltage of each battery cell of the sample battery cluster under the above different temperatures, different charge states, and charging and discharging scenarios is obtained, and based on the terminal voltage, the terminal voltage of the reference battery cell can be calculated to obtain a second two-dimensional table.

[0058] In an example, after the second two-dimensional table is determined, the charging consistency coefficient may be determined according to the second two-dimensional table. The charging consistency coefficient determined according to the second two-dimensional table may be determined by formula (2).

[0059] (2)

[0060] Among them, SOC max and SOC min are the maximum and minimum values ​​of the difference between the state of charge of the single cells in the battery cluster and the state of charge of the reference cell, is the charge consistency coefficient mentioned above.

[0061] That is, for the battery cluster whose real-time available capacity is to be measured, the current temperature and whether it is a charging or discharging scenario are determined, and the corresponding second two-dimensional table is selected. Then, in the second two-dimensional table, the state of charge of each battery cell in the battery cluster at the same terminal voltage is obtained, and the difference between the maximum and minimum state of charge is calculated. The difference is substituted into formula (2), and the result is obtained as the charge consistency coefficient.

[0062] When the temperature correction coefficient, charge consistency coefficient and life attenuation coefficient are known, the three coefficients are multiplied with the rated capacity in sequence to obtain the real-time available capacity of the battery cluster.

[0063] In this embodiment, the first two-dimensional table and the second two-dimensional table may be predetermined. For example, Table 1 is the cell capacity of different charge and discharge rates at 10 degrees Celsius, i.e., the first two-dimensional table at 10 degrees Celsius.

[0064] Table 1 Charge and discharge capacity at different rates at 110℃

[0065]

[0066] The second two-dimensional table measured is shown in Table 2 and Table 3. Table 2 is the terminal voltage (Open circuit voltage, OVC)-state of charge (State of Charge, SOC) table for the 10℃ discharge scenario, and Table 3 is the OCV-SOC table for the 10℃ charging scenario. The average values ​​in Tables 1 to 3 are the data of the benchmark battery cells. Based on Tables 2 and 3, Table 4 can be obtained. Table 4 is the OCV-SOC table at 10℃, which is calculated by adding the average values ​​of Tables 2 and 3 and then dividing by 2.

[0067] Table 210℃ discharge OCV-SOC table

[0068]

[0069] Table 3 10℃ Charging OCV-SOC Table

[0070]

[0071] Table 4 10℃ OCV-SOC table

[0072]

[0073] The rated capacity of the battery cell of the sample battery cluster is 33 Ah, and when fully charged, the state of charge SOH is 100%.

[0074] If you want to calculate the real-time available capacity of a battery cluster, for example, take 5 battery cells connected in series to form a battery cluster. The rated capacity of the 5 cells is 33Ah, and the charge and discharge rate is 1.5C. The initial SOC = 50%, then use the first two-dimensional table and the second two-dimensional table to determine the coefficient, and then use the coefficient to adjust the rated capacity to obtain the real-time available capacity. This can be determined using formula (3).

[0075] OH (3)

[0076] in, is the real-time available capacity, is the rated capacity, is the temperature correction coefficient, is the single-cell SOC consistency correction coefficient.

[0077] Determine the temperature correction coefficient according to the first two-dimensional table. The temperature correction coefficient at 10°C According to the linear lookup table of the actual temperature of the battery cell and the capacity rate table, the table capacity can be obtained to be 29.388Ah. Since the charging rate is 1.5C, and the first two-dimensional table only has data under 1C and 2C, the linear difference part is calibrated to 1.577Ah through linear interpolation, and the actual capacity is 30.965Ah, so the temperature correction coefficient at 10℃ is Value is . The temperature correction coefficient is then calculated.

[0078] For the charge consistency coefficient, when the initial SOC=50%, the average OCV voltage of the five monomers (benchmark capacity, as shown in Table 4) and the average actual available charge and discharge capacity (as shown in Table 1) are calculated as the characteristic parameters of the benchmark monomer. The five monomers and the benchmark monomer are used as inputs to identify the OCV difference between the five monomers and the benchmark monomer using the difference model. Then, the SOC difference between each monomer and the benchmark monomer is determined by looking up the temperature-based OCV-SOC two-dimensional table, and the real-time estimated SOC value of each monomer is obtained as shown in Table 5 below. and They are 49.2% and 46.5% respectively, and the SOC consistency correction coefficient of the monomer is obtained. .

[0079] Table 5 10℃ Estimated SOC values ​​of each monomer

[0080]

[0081] Life reduction coefficient OH can set empirical values ​​based on historical data.

[0082] Finally, the real-time available capacity of the battery cluster is obtained for

[0083] OH=33Ah*93.8%*97.3%*100%=30.128Ah. The temperature correction factor can be expressed as a percentage.

[0084] That is to say, based on the known battery cluster benchmark capacity, the temperature consistency coefficient, the cell SOC consistency coefficient and the SOH coefficient are introduced. Taking 5 cells of 33Ah LTO battery cells connected in series into a battery cluster, with an initial SOC of 50%, and a 1.5C rate charging condition at 10°C as an example, the actual available capacity of the battery cluster is 30.128Ah after real-time dynamic correction, which is closer to the actual predicted available capacity of the battery cluster.

[0085] After obtaining the real-time available capacity of the battery cluster, the real-time SOC of the battery cluster can be calculated, for example, by using formula (4).

[0086] (4)

[0087] Where I is the battery cluster current, which is negative during charging and positive during discharging. is the real-time available capacity calculated above.

[0088] In this embodiment, for the battery cluster difference model, the model structure is as follows: Figure 4 Taking one cell in the battery cluster as the benchmark, considering the internal resistance and OCV differences between other cells and the benchmark cell, the figure shows , They are the internal resistance difference and terminal voltage OCV difference between the monomer numbered i and the reference monomer, and I is the current.

[0089] The discretized state equation of the model is:

[0090] (5)

[0091] If written in standard form, it is

[0092] Among them , , .

[0093] When using the battery cluster difference model to calculate the OCV difference between cells, since the inconsistency of the battery cluster cells is manifested as a gradual change characteristic, the corresponding difference model is low-frequency modeling. Therefore, the data of a time interval can be used to identify the OCV difference within that period of time. The length of the time interval is called the window length, and the identification result is used as the OCV difference between the battery cluster cell and the reference cell at any time within the window length. For operating conditions with a longer duration, a moving window is used to identify the OCV difference in real time. Since the magnitude of the OCV difference is small, it is easily disturbed and produces large errors. A low-pass filter can be used to eliminate high-frequency noise components. In order to overcome the coefficient matrix And the output matrix At the same time, there is a biased estimation problem caused by measurement errors. The total least squares method is used within each window length to achieve unbiased estimation of the parameters.

[0094] Figure 5 This is a schematic diagram of the structure of a device for determining the available capacity of a battery cluster provided in an embodiment of the present application. Figure 5 As shown, the available capacity determination device of the battery cluster comprises:

[0095] A first determining module 502, configured to determine a rated available capacity of the battery cluster;

[0096] The adjustment module 504 is used to adjust the rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the temperature correction coefficient is calculated by a first two-dimensional table, the first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the charge consistency coefficient is calculated by querying the state of charge difference obtained by the terminal voltage difference of each single cell in the sample battery cluster and the reference cell of the sample battery cluster in the second two-dimensional table, the second two-dimensional table records the corresponding relationship between the terminal voltage and the state of charge of each single cell in the sample battery cluster at different temperatures, and the life attenuation coefficient is calculated according to the life attenuation data of the sample battery cluster;

[0097] The second determining module 506 is configured to determine the adjusted capacity as the real-time available capacity of the battery cluster.

[0098] In this embodiment, the above-mentioned device for determining the available capacity of the battery cluster can be used in the process of determining the available capacity of the battery cluster. A battery cluster is a combination of batteries obtained by connecting multiple battery (battery cell) monomers in series or in parallel or in series and parallel. For example, three batteries are connected in series to form a battery cluster. A battery monomer is a battery. The battery cluster includes a rated available capacity, which can be a measured or estimated capacity, or the initial available capacity of the battery cluster after production.

[0099] The real-time available capacity of the battery cluster will fluctuate with the use of the battery cluster, ambient temperature, etc. In order to measure the accurate real-time available capacity, this embodiment proposes to use at least one of the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient to adjust the rated available capacity, so as to obtain the adjusted rated available capacity. The adjusted rated available capacity is regarded as the real-time available capacity of the battery cluster.

[0100] In this embodiment, when at least one of the temperature correction coefficient, the charge consistency coefficient, and the life attenuation coefficient is used to adjust the rated available capacity, if one of the coefficients is used to adjust the rated available capacity, the rated available capacity is directly multiplied by the coefficient; if multiple coefficients are used to adjust the rated available capacity, the rated available capacity is multiplied by each coefficient in turn, and the result is used as the real-time available capacity. In the following example, the temperature correction coefficient, the charge consistency coefficient, and the life attenuation coefficient are used to adjust the rated available capacity together, which does not constitute a unique limitation of this embodiment.

[0101] The temperature correction coefficient is calculated by a first two-dimensional table, which records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates.

[0102] The charge consistency coefficient is calculated by querying a second two-dimensional table to obtain the charge state difference based on the terminal voltage difference between each single cell in the sample battery cluster and the reference cell of the sample battery cluster. The second two-dimensional table records the corresponding relationship between the terminal voltage and the charge state of each single cell in the sample battery cluster at different temperatures.

[0103] The above life attenuation coefficient is calculated based on the life attenuation data of the above sample battery cluster. The life attenuation of the sample battery cluster as it is used can be viewed through historical data. The life attenuation directly affects the real-time available capacity. The life attenuation coefficient is calculated based on the life attenuation data.

[0104] The above-mentioned sample battery cluster is a battery cluster for testing used in the process of determining the first two-dimensional table and the second two-dimensional table. For example, battery cells from the same batch can be regarded as battery cells with similar properties, and some of the battery cells are combined into a battery cluster. The battery cluster is used as a sample battery cluster to construct the first two-dimensional table and the second two-dimensional table. The constructed two-dimensional table can be used to determine the temperature correction coefficient and charge consistency coefficient of other battery clusters formed by combining battery cells from the same batch.

[0105] The solution provided by the embodiment of the present application determines the rated available capacity in the above-mentioned battery cluster; adjusts the above-mentioned rated available capacity using at least one of a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the above-mentioned temperature correction coefficient is calculated by a first two-dimensional table, the above-mentioned first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the above-mentioned charge consistency coefficient is calculated by querying the state of charge difference obtained by querying the second two-dimensional table based on the terminal voltage difference between each single cell in the above-mentioned sample battery cluster and the reference cell of the above-mentioned sample battery cluster, the above-mentioned second two-dimensional table records the corresponding relationship between the terminal voltage and the state of charge of each single cell in the above-mentioned sample battery cluster at different temperatures, and the above-mentioned life attenuation coefficient is calculated according to the life attenuation data of the above-mentioned sample battery cluster; the above-mentioned adjusted capacity is determined as the real-time available capacity of the above-mentioned battery cluster, thereby improving the determination accuracy of the real-time available capacity of the battery cluster, and then determining the actual state of charge according to the real-time available capacity.

[0106] For other examples of this embodiment, please refer to the above examples and will not be described in detail here.

[0107] like Figure 6As shown, an embodiment of the present application provides an electronic device, including a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114.

[0108] Memory 113, used for storing computer programs;

[0109] In one embodiment of the present application, the processor 111 is configured to implement the method for determining the available capacity of a battery cluster provided by any one of the aforementioned method embodiments when executing a program stored in the memory 113 .

[0110] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for determining the available capacity of a battery cluster provided in any one of the aforementioned method embodiments is implemented.

[0111] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0112] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0113] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0114] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for determining the available capacity of a battery cluster, characterized in that: include: determining a rated available capacity in the battery cluster; The rated available capacity is adjusted using a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the temperature correction coefficient is calculated by a first two-dimensional table, the first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the charge consistency coefficient is calculated by querying a second two-dimensional table for a state of charge difference between the terminal voltage difference of each single cell in the sample battery cluster and a reference cell of the sample battery cluster, the second two-dimensional table records a corresponding relationship between the terminal voltage and the state of charge of each single cell in the sample battery cluster at different temperatures, and the life attenuation coefficient is calculated based on the life attenuation data of the sample battery cluster; Determining the adjusted capacity as the real-time available capacity of the battery cluster; Wherein, before adjusting the rated available capacity using the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient to obtain the adjusted capacity, the method further includes: Obtaining the cell capacity of each single cell of the sample battery cluster under different temperatures and different current rates; determining the average cell capacity of each single cell as the cell capacity of the reference cell; The terminal voltage of each single cell in the sample battery cluster at different temperatures and at different states of charge is obtained; the average of the terminal voltages of each single cell at different states of charge is determined as the terminal voltage of the reference cell at different states of charge of the sample battery cluster; the terminal voltage of each single cell in the sample battery cluster at different temperatures and different states of charge and the terminal voltage of the reference cell at different temperatures and different states of charge are determined as the second two-dimensional table.

2. The method according to claim 1, characterized in that The rated available capacity is adjusted using a temperature correction coefficient, a charge consistency coefficient, and a life attenuation coefficient to obtain an adjusted capacity including: The temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient are successively multiplied by the rated available capacity to obtain the adjusted capacity.

3. The method according to claim 1, characterized in that Before adjusting the rated available capacity using the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient to obtain the adjusted capacity, the method further includes: The cell capacity of each single cell in the sample battery cluster at different temperatures and different current rates and the cell capacity of the reference cell at different temperatures and different current rates are determined as the first two-dimensional table.

4. The method according to claim 1, characterized in that Determining the charging consistency coefficient according to the second two-dimensional table includes: The charge consistency coefficient is determined by the following formula: （2） Among them, SOC max and SOC min are the maximum and minimum values ​​of the difference between the state of charge of the single cells in the battery cluster and the state of charge of the reference cell, is the charging consistency coefficient.

5. The method according to claim 1, characterized in that The first two-dimensional table and the second two-dimensional table include a charging two-dimensional table in a charging state and a discharging two-dimensional table in a discharging state.

6. A device for determining the available capacity of a battery cluster, characterized in that: include: A first determination module, configured to determine a rated available capacity in the battery cluster; An adjustment module, used for adjusting the rated available capacity using a temperature correction coefficient, a charge consistency coefficient and a life attenuation coefficient to obtain an adjusted capacity, wherein the temperature correction coefficient is calculated by a first two-dimensional table, the first two-dimensional table records the cell capacity of each single cell in the sample battery cluster under different temperatures and different current rates, the charge consistency coefficient is calculated by querying a second two-dimensional table for a state of charge difference between the terminal voltage difference of each single cell in the sample battery cluster and a reference cell of the sample battery cluster, the second two-dimensional table records a correspondence between the terminal voltage and the state of charge of each single cell in the sample battery cluster at different temperatures, and the life attenuation coefficient is calculated based on the life attenuation data of the sample battery cluster; A second determining module, configured to determine the adjusted capacity as the real-time available capacity of the battery cluster; Before adjusting the rated available capacity using the temperature correction coefficient, the charge consistency coefficient and the life attenuation coefficient to obtain the adjusted capacity, the method further includes: Obtaining the cell capacity of each single cell of the sample battery cluster under different temperatures and different current rates; determining the average cell capacity of each single cell as the cell capacity of the reference cell; The terminal voltage of each single cell in the sample battery cluster at different temperatures and at different states of charge is obtained; the average of the terminal voltages of each single cell at different states of charge is determined as the terminal voltage of the reference cell at different states of charge of the sample battery cluster; the terminal voltage of each single cell in the sample battery cluster at different temperatures and different states of charge and the terminal voltage of the reference cell at different temperatures and different states of charge are determined as the second two-dimensional table.

7. An electronic device, characterized in that: include: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor coupled to the at least one bus; At least one memory connected to the at least one bus, wherein a computer program is stored in the memory, and when the processor executes the computer program, the method for determining the available capacity of a battery cluster as claimed in any one of claims 1 to 5 is implemented.

8. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the method for determining the available capacity of a battery cluster according to any one of claims 1 to 5 of the present application.

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