A method for determining a temperature threshold of an electric cell, a calculation module and a device

Abstract

The application provides a method for determining a temperature threshold of an electric core, a calculation module and a device. The method comprises: during a full charging test of a sample electric core according to a preset charging current and voltage, collecting the electric core temperature of each sampling point corresponding to each first temperature sensor and second temperature sensor based on a corresponding charging sampling frequency; for any temperature sensor, determining a first function curve of the corresponding sampling point based on the electric core temperature of the corresponding sampling point at each sampling time; intercepting a temperature field sheet from the set of first function curves of the corresponding sampling point of each first temperature sensor, and determining the electric core temperature corresponding to the charging time of the first temperature field sheet in the first function curve of the corresponding sampling point of the second temperature sensor as the electric core temperature threshold of the target batch of electric cores when charging according to the preset charging current and voltage. By establishing the corresponding relationship between the electric core temperature of the preset temperature sampling position and the overall electric core temperature field, the accuracy of the determination of the electric core temperature threshold is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, a calculation module, and a device for determining a battery cell temperature threshold. Background Art

[0002] A battery pack is a modular system composed of multiple cells, commonly used in electric vehicles and energy storage systems. Because cells generate heat during charging and discharging, excessively high cell temperatures can lead to capacity degradation, shortened lifespan, and even thermal runaway. Therefore, monitoring cell temperature has a significant impact on the performance and safety of the battery pack.

[0003] Existing methods for measuring battery cell temperature typically place a negative temperature coefficient (NTC) thermistor between the battery cell pole and the explosion-proof valve. The temperature of the battery cell between the battery cell pole and the explosion-proof valve is sensed through temperature sensing to represent the overall temperature level of the battery cell. However, due to the limitations of the NTC placement, the temperature of the battery cell between the battery cell pole and the explosion-proof valve is often higher than the overall temperature of the battery cell and cannot represent the overall temperature level of the battery cell. As a result, the accuracy of the battery cell temperature threshold determined based on this is low, and the battery pack performance margin is large, which affects the overall performance of the battery pack. Summary of the Invention

[0004] In view of this, the embodiments of the present application at least provide a method, calculation module and device for determining the battery cell temperature threshold, which improves the accuracy of determining the battery cell temperature threshold by establishing a correspondence between the battery cell temperature at a preset temperature sampling position and the overall temperature field of the battery cell.

[0005] This application mainly includes the following aspects:

[0006] In a first aspect, an embodiment of the present application provides a method for determining a battery cell temperature threshold, which is applied to a calculation module of a device for determining a battery cell temperature threshold. The device for determining the battery cell temperature threshold further includes a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at the outer shell of a sample battery cell; the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; the plurality of first temperature sensors and the second temperature sensors are electrically connected to the calculation module respectively; the method includes:

[0007] During a full charge test of the sample battery cell according to a preset charging current and voltage, collecting the battery cell temperatures at corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor based on a charging sampling frequency corresponding to the full charge test; the sample battery cell is any battery cell in a target batch of battery cells;

[0008] For any one of the first temperature sensor and the second temperature sensor, determining a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature at the corresponding sampling point collected at each sampling moment; the first function curve is an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the charging time;

[0009] A temperature field sheet is intercepted from the set of first function curves corresponding to the sampling points of each of the first temperature sensors, and the battery cell temperature corresponding to the charging time of the first temperature field sheet in the first function curve corresponding to the sampling point of the second temperature sensor is determined as the battery cell temperature threshold of the target batch of battery cells when charged according to the preset charging current and voltage; the first temperature field sheet is a temperature field sheet whose ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

[0010] In a second aspect, an embodiment of the present application further provides a calculation module, which is applied to a device for determining a battery cell temperature threshold, wherein the device for determining a battery cell temperature threshold further includes a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at the outer shell of a sample battery cell; the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; the plurality of first temperature sensors and the second temperature sensors are electrically connected to the calculation module respectively; the calculation module includes:

[0011] a first sampling unit configured to collect the cell temperatures of corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor during a full charge test of the sample cell according to a preset charging current and voltage, based on a charging sampling frequency corresponding to the full charge test; the sample cell being any cell in a target batch of cells;

[0012] a first determining unit configured to determine, for any one of the first temperature sensor and the second temperature sensor, a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature at the corresponding sampling point collected at each sampling moment; the first function curve being an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the charging time;

[0013] The second determining unit is used to intercept a temperature field sheet from the set of first function curves corresponding to the sampling points of each of the first temperature sensors, and determine the battery cell temperature corresponding to the charging time of the first temperature field sheet in the first function curve corresponding to the sampling point of the second temperature sensor as the battery cell temperature threshold of the target batch of battery cells when charged according to the preset charging current and voltage; the first temperature field sheet is a temperature field sheet whose proportion of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold relative to all the first temperature sensors is equal to the preset proportion.

[0014] In a third aspect, the embodiments of the present application further provide a device for determining a temperature threshold of an electric core, the device comprising:

[0015] a plurality of first temperature sensors, a second temperature sensor, and a calculation module as described above; the plurality of first temperature sensors are located at the shell position of the sample electric core; the second temperature sensor is located at the preset temperature sampling position of the sample electric core; the plurality of first temperature sensors and the second temperature sensor are electrically connected to the calculation module respectively.

[0016] In a fourth aspect, the embodiments of the present application further provide an electronic device, comprising: a processor, a memory, and a bus, the memory stores machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, when the machine readable instructions are executed by the processor, the steps of the method for determining the temperature threshold of the electric core are executed.

[0017] In a fifth aspect, the embodiments of the present application further provide a computer readable storage medium, the computer readable storage medium stores a computer program, when the computer program is executed by a processor, the steps of the method for determining the temperature threshold of the electric core are executed.

[0018] The embodiments of the present application provide a method, a calculation module, and a device for determining a battery cell temperature threshold, wherein the method is applied to a calculation module of a device for determining a battery cell temperature threshold, and the device for determining a battery cell temperature threshold further comprises a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at the outer shell of a sample battery cell; the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; the plurality of first temperature sensors and the second temperature sensors are electrically connected to the calculation module respectively; the method comprises: in the process of performing a full charge test on the sample battery cell according to a preset charging current and voltage, based on the charging sampling frequency corresponding to the full charge test, collecting the battery cell temperatures of the corresponding sampling points collected by each first temperature sensor and the second temperature sensor; the sample battery cell is any battery cell in a target batch of battery cells; for any first The temperature sensor and the second temperature sensor determine a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the cell temperature at the corresponding sampling point collected at each sampling moment. The first function curve is an exponential function curve of the cell temperature at the corresponding sampling point relative to the charging time. A temperature field slice is intercepted from the set of first function curves corresponding to the sampling points of each first temperature sensor, and the cell temperature corresponding to the charging time of the first temperature field slice in the first function curve corresponding to the sampling point of the second temperature sensor is determined as the cell temperature threshold of the target batch of cells when charged at a preset charging current and voltage. The first temperature field slice is the temperature field slice where the ratio of the first temperature sensor with a cell temperature greater than the preset temperature threshold relative to all first temperature sensors is equal to the preset ratio. In this way, by establishing a corresponding relationship between the cell temperature at the preset temperature sampling position and the overall temperature field of the cell, the accuracy of determining the cell temperature threshold is improved.

[0019] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic structural diagram of a device for determining a battery cell temperature threshold value provided by an embodiment of the present application is shown;

[0022] Figure 2 A flow chart showing a method for determining a battery cell temperature threshold provided in an embodiment of the present application is shown;

[0023] Figure 3 A flow chart showing another method for determining a battery cell temperature threshold provided in an embodiment of the present application is shown;

[0024] Figure 4 One of the functional module diagrams of a computing module provided in an embodiment of the present application is shown;

[0025] Figure 5 The second functional module diagram of a computing module provided in an embodiment of the present application is shown;

[0026] Figure 6 A schematic structural diagram of an electronic device provided in an embodiment of the present application is shown.

[0027] Description of main component symbols:

[0028] In the figure: 100 - a device for determining a battery cell temperature threshold; 101 - a first temperature sensor; 102 - a second temperature sensor; 103 - a calculation module; 1031 - a first sampling unit; 1032 - a first determination unit; 1033 - a second determination unit; 1034 - a first matrix generation unit; 1035 - a second sampling unit; 1036 - a third determination unit; 1037 - a fourth determination unit; 1038 - a second matrix generation unit; 600 - an electronic device; 610 - a processor; 620 - a memory; 630 - a bus. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions 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 only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0030] The following will be combined Figure 1 The implementation of the embodiment of the present application is described in detail; the embodiment of the present application provides a method for determining a battery cell temperature threshold, which is applied to a calculation module of a device for determining a battery cell temperature threshold.

[0031] See also Figure 1 , Figure 1 The schematic diagram of the structure of a device for determining a battery cell temperature threshold provided in an embodiment of the present application. The method for determining a battery cell temperature threshold provided in an embodiment of the present application can be applied to Figure 1 The calculation module 103 in the device for determining the battery cell temperature threshold shown in the figure, the device 100 for determining the battery cell temperature threshold may include: multiple first temperature sensors 101, second temperature sensors 102 and a calculation module 103; the multiple first temperature sensors 101 are located at the outer shell position of the sample battery cell; the second temperature sensor 102 is located at the preset temperature sampling position of the sample battery cell; the multiple first temperature sensors 101 and the second temperature sensors 102 are electrically connected to the calculation module 103 respectively.

[0032] The plurality of first temperature sensors 101 are used to collect the cell temperatures at sampling points corresponding to the outer shell positions of the sample cells.

[0033] In the embodiment of the present application, the plurality of first temperature sensors 101 are NTC thermistors, such as Figure 1 As shown, m×n NTCs are arranged according to the dimensions X and Z of the cell housing, so that m / n=X / Z.

[0034] The second temperature sensor 102 is used to collect the cell temperature of the sample battery at a sampling point at a preset temperature sampling position.

[0035] In the embodiment of the present application, the second temperature sensor 102 is a thermistor NTC, such as Figure 1 As shown, depending on the installation position of the battery cell in the battery pack, the preset temperature sampling position can be installed on both sides of the positive electrode column or the negative electrode column of the battery cell.

[0036] A method for determining a battery cell temperature threshold provided in an embodiment of the present application is described in detail below. The method for determining a battery cell temperature threshold can be applied to the calculation module of the above-mentioned device for determining a battery cell temperature threshold.

[0037] See also Figure 2 , Figure 2 This is a flow chart of a method for determining a battery cell temperature threshold provided in an embodiment of the present application. Figure 2 As shown, the method for determining the battery cell temperature threshold provided in the embodiment of the present application includes the following steps:

[0038] S201, during a full charge test of the sample battery cell according to a preset charging current and voltage, collecting the battery cell temperatures of corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor based on a charging sampling frequency corresponding to the full charge test; the sample battery cell is any battery cell in a target batch of battery cells.

[0039] In this embodiment, a cell is selected from a target batch of cells as a sample cell for a full-charge test. During the full-charge test of the sample cell at a preset charging current and voltage, the cell temperatures at corresponding sampling points, as detected by each first temperature sensor and second temperature sensor, are collected based on the corresponding charging sampling frequency. Specifically, a charging matrix A[i,m,n] is established, where i represents the temperature matrix at time i. During a full-charge test, the temperature of the NTC at time i, with row m and column n, is stored in the charging matrix A[i,m,n].

[0040] S202: For any one of the first temperature sensor and the second temperature sensor, determine a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature of the corresponding sampling point collected at each sampling moment; the first function curve is an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the charging time.

[0041] In this embodiment, for any sampling point corresponding to the first or second temperature sensor, exponential fitting is performed on all points [:, m, n] at the corresponding sampling point using the charging matrix A. Specifically, with charging time i as the horizontal axis and A[:, m, n] as the vertical axis, the fitting yields an exponential function curve for that sampling point over time, i.e., the first function curve. This step is repeated for m×n sampling points on the battery cell to obtain the first function curve for the sampling point corresponding to the first or second temperature sensor.

[0042] S203, intercepting a temperature field sheet from the set of first function curves corresponding to the sampling points of each of the first temperature sensors, and determining the battery cell temperature corresponding to the charging time of the first temperature field sheet in the first function curve corresponding to the sampling point of the second temperature sensor as the battery cell temperature threshold of the target batch of battery cells when charged according to the preset charging current and voltage; the first temperature field sheet is a temperature field sheet whose ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

[0043] In the embodiments of the present application, after obtaining the first function curve of all sampling points, the temperature field pieces are intercepted from the set of first function curves of the sampling points corresponding to each first temperature sensor through different charging times, and when the number of points whose temperature is greater than the preset temperature threshold accounts for 10% of all first temperature sensor corresponding sampling points, the temperature of the second temperature sensor corresponding sampling point is the representative temperature of the battery cell at the current i charging moment, which is also the highest performance release degree of the battery cell. The temperature is determined as the battery cell temperature threshold of the target batch battery cell when charging according to the preset charging current and voltage. In order to actually measure the battery cell temperature, if the measured battery cell temperature is greater than the battery cell temperature threshold, it is determined that the overall temperature of the battery cell is too high, and the battery cell needs to be cooled; if the measured battery cell temperature is less than or equal to the battery cell temperature threshold, it is determined that the overall temperature of the battery cell is normal, and the battery cell does not need to be cooled.

[0044] Further, the charging sampling frequency corresponding to the full charging test is determined according to the following steps:

[0045] Step a1, obtaining the full charging time of the sample battery cell according to the preset charging current and voltage for full charging test.

[0046] In this step, the full charging time T is obtained by performing a full charging test on the sample battery cell according to the preset charging current and voltage.

[0047] Step a2, determining the charging sampling frequency corresponding to the full charging test based on the full charging time and the preset interpolation density.

[0048] In this step, the preset interpolation density Q is taken, and the charging sampling frequency corresponding to the full charging test is T / Q.

[0049] Further, S202 specifically includes:

[0050] Step b1, obtaining a standard exponential function expression, and converting the standard exponential function expression into a linear function expression to establish a parameter correspondence relationship between a first target parameter in the standard exponential function expression and a second target parameter in the linear function expression.

[0051] In this step, let Y mn = ae bx be a standard exponential function expression, where a and b are first target parameters. In order to simplify the calculation, the natural logarithm of both sides of the equation is taken:

[0052] ln Y mn = bx+ln a; at this time, variable substitution is performed, let y = ln Y mn ; b = c1; ln a = c2; the standard exponential function expression is converted into a linear function expression:

[0053] y=c1x+c2; where c1 and c2 are the second target parameters.

[0054] Step b2: Substitute the set of battery cell temperatures of corresponding sampling points collected at each sampling moment into the linear function expression to perform linear regression fitting to determine the second target parameter.

[0055] In this step, the set of time and temperature data of any sampling point (i, A[i, m, n]) is substituted into the above linear function expression for linear regression fitting, and the basis functions φ0=1; φ1=x are taken; and the values ​​of parameters c1 and c2 are obtained by solving.

[0056] Step b3: Determine the first target parameter according to the second target parameter and the parameter correspondence.

[0057] In this step, according to the correspondence between the second target parameter and the first target parameter:

[0058] b=c1; Solve to obtain the values ​​of parameters a and b.

[0059] Step b4: determining the residual value of the standard exponential function expression based on the first target parameter and the least squares method.

[0060] In this step, during the fitting process, the residuals (the difference between the actual value and the fitted value) are calculated. If there is a systematic offset in the residuals, it can be used as a constant term c;

[0061] Specifically, suppose there is a set of data points (x i , Y {mn,i} ), the parameters a, b and c can be fitted by the least squares method;

[0062] Specifically, the initial fitting parameters a, b; ln(Y mn,i -c)=bx i +ln a;

[0063] Calculate residuals;

[0064] Optimize c to minimize the residual:

[0065]

[0066] Step b5: determining a first function curve corresponding to the sampling points of the first temperature sensor or the second temperature sensor according to the standard exponential function expression, the first target parameter, and the residual value.

[0067] In this step, the first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor is determined according to the values ​​of the solved parameters a, b and c: mn =ae bx +c.

[0068] Furthermore, the method further comprises:

[0069] The sample cells are fully charged according to different charging currents and voltages to determine the cell temperature thresholds of the target batch of cells when charged according to the corresponding charging currents and voltages, and the cell temperature thresholds and the corresponding charging currents and voltages are stored in a cell temperature threshold matrix.

[0070] In an embodiment of the present application, full charge tests are repeatedly performed on sample cells according to different charging currents and voltages, and the cell temperature thresholds and the corresponding charging currents and voltages determined according to the above steps are stored in a cell temperature threshold matrix, so that when the cell temperature is actually measured, the overall cell temperature level can be judged based on the cell temperature at the sampling point corresponding to this matrix and the preset temperature sampling position.

[0071] In one possible implementation, see Figure 3 , Figure 3 This is a flow chart of another method for determining a battery cell temperature threshold provided by an embodiment of the present application. Figure 3 As shown, the method further includes:

[0072] S301, during a full-discharge test of the sample battery cell according to a preset discharge current and voltage, collecting the battery cell temperatures of corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor based on a discharge sampling frequency corresponding to the full-discharge test; the sample battery cell is any battery cell in a target batch of battery cells.

[0073] S302: For any one of the first temperature sensor and the second temperature sensor, determine a second function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature of the corresponding sampling point collected at each sampling moment; the second function curve is an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the discharge time.

[0074] S303, intercepting a temperature field sheet from the set of second function curves corresponding to the sampling points of each of the first temperature sensors, and determining the battery cell temperature corresponding to the discharge time of the second temperature field sheet in the second function curve corresponding to the sampling point of the second temperature sensor as the battery cell temperature threshold of the target batch of battery cells when discharged according to the preset discharge current and voltage; the second temperature field sheet is a temperature field sheet whose ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

[0075] Among them, S301 to S303 are methods for determining the cell temperature threshold during the full discharge test of the sample cell according to the preset discharge current and voltage. The description thereof can refer to the description of S201 to S203, and can achieve the same technical effect, so it will not be repeated here.

[0076] Furthermore, the discharge sampling frequency corresponding to the full discharge test is determined according to the following steps:

[0077] Step c1, obtaining the full discharge time of the sample battery cell when performing a full discharge test according to the preset discharge current and voltage.

[0078] Step c2: determining a discharge sampling frequency corresponding to the full-discharge test based on the full-discharge time and a preset interpolation density.

[0079] Specifically, the description of step c1 to step c2 can refer to the description of step a1 to step a2, and can achieve the same technical effect, which is not repeated here.

[0080] Furthermore, S302 specifically includes:

[0081] Step d1, obtaining a standard exponential function expression, converting the standard exponential function expression into a linear function expression, and establishing a parameter correspondence between a first target parameter in the standard exponential function expression and a second target parameter in the linear function expression.

[0082] Step d2: Substitute the set of battery cell temperatures of corresponding sampling points collected at each sampling moment into the linear function expression to perform linear regression fitting to determine the second target parameter.

[0083] Step d3: Determine the first target parameter according to the second target parameter and the parameter correspondence.

[0084] Step d4: determining the residual value of the standard exponential function expression based on the first target parameter and the least squares method.

[0085] Step d5: determining a second function curve corresponding to the sampling points of the first temperature sensor or the second temperature sensor according to the standard exponential function expression, the first target parameter, and the residual value.

[0086] Specifically, the description of steps d1 to d5 can refer to the description of steps b1 to b5, and can achieve the same technical effects, so they will not be described in detail.

[0087] Furthermore, the method further comprises:

[0088] The sample cells are fully discharged according to different discharge currents and voltages to determine the cell temperature thresholds of the target batch of cells when discharged according to the corresponding discharge currents and voltages, and the cell temperature thresholds and the corresponding discharge currents and voltages are stored in a cell temperature threshold matrix.

[0089] In an embodiment of the present application, full discharge tests are repeatedly performed on sample cells according to different discharge currents and voltages, and the cell temperature thresholds and the corresponding discharge currents and voltages determined according to the above steps are stored in a cell temperature threshold matrix, so that when the cell temperature is actually measured, the overall cell temperature level can be judged based on this matrix and the cell temperature of the sampling point corresponding to the preset temperature sampling position.

[0090] The embodiment of the present application provides a method for determining a battery cell temperature threshold, which is applied to a calculation module of a device for determining a battery cell temperature threshold, wherein the device for determining a battery cell temperature threshold further comprises a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at the outer shell of a sample battery cell; the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; the plurality of first temperature sensors and the second temperature sensors are electrically connected to the calculation module respectively; the method comprises: in a process of performing a full charge test on the sample battery cell according to a preset charging current and voltage, based on a charging sampling frequency corresponding to the full charge test, collecting the battery cell temperatures of corresponding sampling points collected by each first temperature sensor and the second temperature sensor; the sample battery cell is any battery cell in a target batch of battery cells; for any first temperature sensor Based on the cell temperatures at the corresponding sampling points collected at each sampling moment, a first function curve corresponding to the first or second temperature sensor is determined. The first function curve is an exponential function curve of the cell temperature at the corresponding sampling point relative to the charging time. A temperature field slice is intercepted from the set of first function curves corresponding to the sampling points of each first temperature sensor, and the cell temperature corresponding to the charging time of the first temperature field slice in the first function curve corresponding to the sampling point of the second temperature sensor is determined as the cell temperature threshold of the target batch of cells when charged at a preset charging current and voltage. The first temperature field slice is the temperature field slice where the ratio of the first temperature sensor with a cell temperature at the corresponding sampling point greater than the preset temperature threshold relative to all first temperature sensors is equal to the preset ratio. In this way, by establishing a corresponding relationship between the cell temperature at the preset temperature sampling position and the overall temperature field of the cell, the accuracy of determining the cell temperature threshold is improved.

[0091] Based on the same application concept, the embodiments of the present application also provide a device for determining the battery cell temperature threshold corresponding to the method for determining the battery cell temperature threshold provided in the above embodiments. Since the principle of solving the problem by the device in the embodiments of the present application is similar to the method for determining the battery cell temperature threshold in the above embodiments of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0092] Referring to Figure 4 , Figure 4 As shown in a functional module diagram of a computing module provided by an embodiment of the present application, the computing module 103 comprises: Figure 4

[0093] A first sampling unit 1031 is configured to, in a process of performing full charging tests on the sample battery cells according to preset charging currents and voltages, collect battery cell temperatures of corresponding sampling points collected by each of the first temperature sensors and the second temperature sensors based on a charging sampling frequency corresponding to the full charging tests; the sample battery cells are any battery cell in a target batch of battery cells.

[0094] A first determining unit 1032 is configured to, for any of the first temperature sensors and the second temperature sensors, determine a first function curve of a corresponding sampling point of the first temperature sensor or the second temperature sensor based on battery cell temperatures of the corresponding sampling point collected at each sampling time; the first function curve is an exponential function curve of the battery cell temperatures of the corresponding sampling point with respect to charging time.

[0095] A second determining unit 1033 is configured to intercept a temperature field piece from a set of first function curves of corresponding sampling points of each of the first temperature sensors, and determine, as a battery cell temperature threshold of the target batch of battery cells when charging according to preset charging currents and voltages, a corresponding battery cell temperature of the first temperature field piece in the first function curve of the corresponding sampling point of the second temperature sensor; the first temperature field piece is a temperature field piece in which a proportion of the first temperature sensor with respect to all the first temperature sensors is equal to a preset proportion, and the battery cell temperatures of the corresponding sampling points are greater than a preset temperature threshold.

[0096] Further, the first sampling unit 1031 is configured to determine the charging sampling frequency corresponding to the full charging tests according to the following steps:

[0097] Obtaining a full charging time of the sample battery cells performing full charging tests according to the preset charging currents and voltages;

[0098] Determining the charging sampling frequency corresponding to the full charging tests based on the full charging time and a preset interpolation density.

[0099] Further, when the first determining unit 1032 is configured to determine the first function curve of the corresponding sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperatures of the corresponding sampling point collected at each sampling time, the first determining unit 1032 is specifically configured to:

[0100] ​Obtaining a standard exponential function expression, converting the standard exponential function expression into a linear function expression, and establishing a parameter correspondence between a first target parameter in the standard exponential function expression and a second target parameter in the linear function expression;

[0101] Substituting the set of battery cell temperatures of corresponding sampling points collected at each sampling moment into the linear function expression to perform linear regression fitting to determine the second target parameter;

[0102] determining the first target parameter according to the second target parameter and the parameter correspondence;

[0103] Determining a residual value of the standard exponential function expression based on the first target parameter and the least squares method;

[0104] A first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor is determined according to the standard exponential function expression, the first target parameter, and the residual value.

[0105] Further, see Figure 5 , Figure 5 This is the second functional module diagram of a computing module provided in the embodiment of the present application. Figure 5 As shown, the calculation module 103 also includes:

[0106] The first matrix generating unit 1034 is configured to perform a full charge test on the sample battery cells according to different charging currents and voltages, determine a battery temperature threshold value of the target batch of battery cells when charged according to the corresponding charging current and voltage, and store the battery temperature threshold value and the corresponding charging current and voltage in a battery temperature threshold value matrix.

[0107] In one possible implementation, Figure 5 As shown, the calculation module 103 also includes:

[0108] The second sampling unit 1035 is used to collect the cell temperatures of the corresponding sampling points collected by the first temperature sensor and the second temperature sensor based on the discharge sampling frequency corresponding to the full discharge test during the full discharge test of the sample cell according to the preset discharge current and voltage; the sample cell is any cell in the target batch of cells.

[0109] The third determining unit 1036 is configured to determine, for any one of the first temperature sensor and the second temperature sensor, a second function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature of the corresponding sampling point collected at each sampling moment; the second function curve is an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the discharge time.

[0110] The fourth determination unit 1037 is used to intercept a temperature field sheet from the set of second function curves corresponding to the sampling points of each of the first temperature sensors, and determine the battery cell temperature corresponding to the discharge time of the second temperature field sheet in the second function curve corresponding to the sampling point of the second temperature sensor as the battery cell temperature threshold of the target batch of battery cells when discharged according to the preset discharge current and voltage; the second temperature field sheet is a temperature field sheet in which the ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

[0111] Furthermore, the second sampling unit 1035 is configured to determine a discharge sampling frequency corresponding to the full discharge test according to the following steps:

[0112] Obtaining the full discharge time of the sample battery cell when performing a full discharge test according to the preset discharge current and voltage;

[0113] Based on the full discharge time and a preset interpolation density, a discharge sampling frequency corresponding to the full discharge test is determined.

[0114] Furthermore, when the third determining unit 1036 is used to determine the second function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature of the corresponding sampling point collected at each sampling moment, the third determining unit 1036 is specifically used to:

[0115] Obtaining a standard exponential function expression, converting the standard exponential function expression into a linear function expression, and establishing a parameter correspondence between a first target parameter in the standard exponential function expression and a second target parameter in the linear function expression;

[0116] Substituting the set of battery cell temperatures of corresponding sampling points collected at each sampling moment into the linear function expression to perform linear regression fitting to determine the second target parameter;

[0117] determining the first target parameter according to the second target parameter and the parameter correspondence;

[0118] Determining a residual value of the standard exponential function expression based on the first target parameter and the least squares method;

[0119] A second function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor is determined according to the standard exponential function expression, the first target parameter, and the residual value.

[0120] Further, if Figure 5 As shown, the calculation module 103 also includes:

[0121] The second matrix generating unit 1038 is used to perform a full discharge test on the sample battery cells according to different discharge currents and voltages, determine the battery cell temperature threshold of the target batch of battery cells when discharged according to the corresponding discharge current and voltage, and store the battery cell temperature threshold and the corresponding discharge current and voltage in a battery cell temperature threshold matrix.

[0122] The calculation module provided in the embodiment of the present application is applied to a device for determining a battery cell temperature threshold value, and the device for determining a battery cell temperature threshold value further comprises a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at the outer shell position of the sample battery cell; the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; the plurality of first temperature sensors and the second temperature sensors are electrically connected to the calculation module respectively; the calculation module comprises: a first sampling unit for collecting the battery cell temperatures at corresponding sampling points collected by each first temperature sensor and the second temperature sensor based on the charging sampling frequency corresponding to the full charge test during a full charge test of the sample battery cell according to a preset charging current and voltage; the sample battery cell is any battery cell in a target batch of battery cells; a first determination unit for collecting the battery cell temperatures at corresponding sampling points collected by each first temperature sensor and the second temperature sensor based on the charging sampling frequency corresponding to the full charge test; the sample battery cell is any battery cell in a target batch of battery cells; The second temperature sensor determines a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the cell temperature at the corresponding sampling point collected at each sampling moment; the first function curve is an exponential function curve of the cell temperature at the corresponding sampling point relative to the charging time; the second determination unit is configured to intercept a temperature field slice from the set of first function curves corresponding to the sampling points of each first temperature sensor, and determine the cell temperature corresponding to the charging time of the first temperature field slice in the first function curve corresponding to the sampling point of the second temperature sensor as the cell temperature threshold of the target batch of cells when charged at a preset charging current and voltage; the first temperature field slice is a temperature field slice where the ratio of the first temperature sensor whose cell temperature at the corresponding sampling point is greater than the preset temperature threshold relative to all first temperature sensors is equal to the preset ratio. In this way, by establishing a corresponding relationship between the cell temperature at the preset temperature sampling position and the overall temperature field of the cell, the accuracy of determining the cell temperature threshold is improved.

[0123] Based on the same application idea, please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 6 As shown, the electronic device 600 includes a processor 610 , a memory 620 and a bus 630 .

[0124] The memory 620 stores machine-readable instructions executable by the processor 610. When the electronic device 600 is running, the processor 610 communicates with the memory 620 through the bus 630. When the processor 610 is running, the machine-readable instructions execute the steps of the method for determining the battery cell temperature threshold provided in the above embodiment. The specific implementation method can be found in the method embodiment and will not be repeated here.

[0125] Based on the same application concept, an embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, the steps of the method for determining the battery cell temperature threshold provided in the above embodiment are executed. The specific implementation method can be found in the method embodiment and will not be repeated here.

[0126] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0127] In the embodiments provided in this application, it should be understood that the disclosed methods, modules and devices can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, the indirect coupling or communication connection of the device or unit can be electrical, mechanical or other forms.

[0128] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0129] In addition, each functional unit in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0130] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0131] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0132] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or make equivalent replacements for some of the technical features thereof. However, these modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application. They should all be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for determining a battery cell temperature threshold, characterized in that: A calculation module applied to a device for determining a battery cell temperature threshold, wherein the device further comprises a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at a housing of a sample battery cell; and the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; The plurality of first temperature sensors and the second temperature sensors are electrically connected to the computing module respectively; the method comprising: During a full charge test of the sample battery cell according to a preset charging current and voltage, collecting the battery cell temperatures at corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor based on a charging sampling frequency corresponding to the full charge test; the sample battery cell is any battery cell in a target batch of battery cells; For any one of the first temperature sensor and the second temperature sensor, determining a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature at the corresponding sampling point collected at each sampling moment; the first function curve is an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the charging time; A temperature field sheet is intercepted from the set of first function curves corresponding to the sampling points of each of the first temperature sensors, and the battery cell temperature corresponding to the charging time of the first temperature field sheet in the first function curve corresponding to the sampling point of the second temperature sensor is determined as the battery cell temperature threshold of the target batch of battery cells when charged according to the preset charging current and voltage; the first temperature field sheet is a temperature field sheet whose ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

2. The method for determining the battery cell temperature threshold according to claim 1, wherein: Determine the charging sampling frequency corresponding to the full charge test according to the following steps: Obtaining a full charge time of the sample battery cell when performing a full charge test according to the preset charging current and voltage; Based on the full charge time and a preset interpolation density, a charging sampling frequency corresponding to the full charge test is determined.

3. The method for determining the battery cell temperature threshold according to claim 1, wherein: The determining of a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature of the corresponding sampling point collected at each sampling moment includes: Obtaining a standard exponential function expression, converting the standard exponential function expression into a linear function expression, and establishing a parameter correspondence between a first target parameter in the standard exponential function expression and a second target parameter in the linear function expression; Substituting the set of battery cell temperatures of corresponding sampling points collected at each sampling moment into the linear function expression to perform linear regression fitting to determine the second target parameter; determining the first target parameter according to the second target parameter and the parameter correspondence; Determining a residual value of the standard exponential function expression based on the first target parameter and the least squares method; A first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor is determined according to the standard exponential function expression, the first target parameter, and the residual value.

4. The method for determining the battery cell temperature threshold according to claim 1, wherein: The method further comprises: The sample cells are fully charged according to different charging currents and voltages to determine the cell temperature thresholds of the target batch of cells when charged according to the corresponding charging currents and voltages, and the cell temperature thresholds and the corresponding charging currents and voltages are stored in a cell temperature threshold matrix.

5. The method for determining the battery cell temperature threshold according to claim 1, wherein: The method further comprises: During a full-discharge test of the sample battery cell according to a preset discharge current and voltage, collecting the battery cell temperatures at corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor based on a discharge sampling frequency corresponding to the full-discharge test; the sample battery cell is any battery cell in a target batch of battery cells; For any one of the first temperature sensor and the second temperature sensor, based on the battery cell temperature at the corresponding sampling point collected at each sampling moment, determining a second function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor; the second function curve is an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the discharge time; A temperature field sheet is intercepted from the set of second function curves corresponding to the sampling points of each of the first temperature sensors, and the battery cell temperature corresponding to the discharge time of the second temperature field sheet in the second function curve corresponding to the sampling point of the second temperature sensor is determined as the battery cell temperature threshold of the target batch of battery cells when discharged according to the preset discharge current and voltage; the second temperature field sheet is a temperature field sheet whose ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

6. A calculation module, characterized in that: The device for determining a cell temperature threshold is applied to a cell temperature threshold, the device further comprising a plurality of first temperature sensors and a second temperature sensor; the plurality of first temperature sensors are located at the outer shell of the sample cell; the second temperature sensor is located at a preset temperature sampling position of the sample cell; A plurality of the first temperature sensors and the second temperature sensors are electrically connected to the computing module respectively; The calculation module includes: a first sampling unit configured to collect the cell temperatures of corresponding sampling points collected by each of the first temperature sensor and the second temperature sensor during a full charge test of the sample cell according to a preset charging current and voltage, based on a charging sampling frequency corresponding to the full charge test; the sample cell being any cell in a target batch of cells; a first determining unit configured to determine, for any one of the first temperature sensor and the second temperature sensor, a first function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature at the corresponding sampling point collected at each sampling moment; the first function curve being an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the charging time; The second determining unit is used to intercept a temperature field sheet from the set of first function curves corresponding to the sampling points of each of the first temperature sensors, and determine the battery cell temperature corresponding to the charging time of the first temperature field sheet in the first function curve corresponding to the sampling point of the second temperature sensor as the battery cell temperature threshold of the target batch of battery cells when charged according to the preset charging current and voltage; the first temperature field sheet is a temperature field sheet whose proportion of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold relative to all the first temperature sensors is equal to the preset proportion.

7. The calculation module according to claim 6, characterized in that: The calculation module also includes: a second sampling unit configured to collect the cell temperatures of corresponding sampling points collected by the first temperature sensor and the second temperature sensor based on a discharge sampling frequency corresponding to the full-discharge test during a full-discharge test of the sample cell according to a preset discharge current and voltage; the sample cell being any cell in a target batch of cells; a third determining unit, configured to determine, for any one of the first temperature sensor and the second temperature sensor, a second function curve corresponding to the sampling point of the first temperature sensor or the second temperature sensor based on the battery cell temperature at the corresponding sampling point collected at each sampling moment; the second function curve being an exponential function curve of the battery cell temperature at the corresponding sampling point relative to the discharge time; The fourth determination unit is used to intercept a temperature field sheet from the set of second function curves corresponding to the sampling points of each of the first temperature sensors, and determine the battery cell temperature corresponding to the discharge time of the second temperature field sheet in the second function curve corresponding to the sampling point of the second temperature sensor as the battery cell temperature threshold of the target batch of battery cells when discharged according to the preset discharge current and voltage; the second temperature field sheet is a temperature field sheet in which the ratio of the first temperature sensor whose battery cell temperature at the corresponding sampling point is greater than the preset temperature threshold to all the first temperature sensors is equal to the preset ratio.

8. A device for determining a battery cell temperature threshold, characterized in that: The device for determining the battery cell temperature threshold comprises: A plurality of first temperature sensors, a second temperature sensor and a calculation module as described in any one of claims 6 to 7; the plurality of first temperature sensors are located at the outer shell position of the sample battery cell; the second temperature sensor is located at a preset temperature sampling position of the sample battery cell; the plurality of first temperature sensors and the second temperature sensors are electrically connected to the calculation module respectively.

9. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the memory communicate through the bus. When the processor is running, the machine-readable instructions execute the steps of the method for determining the battery cell temperature threshold as described in any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for determining the battery cell temperature threshold value according to any one of claims 1 to 5 are executed.

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