Power battery consistency testing method and device

Abstract

The embodiment of the present application discloses a consistency test method and device for a power battery, which belongs to the field of battery technology. The method comprises: in response to a first acquisition instruction, acquiring the voltage of each single cell in a plurality of single cells in a target charge state, obtaining a plurality of first voltages corresponding one-to-one to the plurality of single cells, and the target charge state indicates that the power of the power battery is the target power. In response to a second acquisition instruction, acquiring the voltage of each single cell in a plurality of single cells in a target charge state, obtaining a plurality of second voltages corresponding one-to-one to the plurality of single cells, and the duration between the triggering time of the second acquisition instruction and the triggering time of the first acquisition instruction exceeds the reference duration. Based on the plurality of first voltages and the plurality of second voltages, the consistency between the plurality of single cells is tested. The embodiment of the present application accurately describes the consistency of the power battery by testing the consistency between the plurality of single cells over a period of time.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of battery technology, and in particular to a consistency testing method and device for a power battery. Background Art

[0002] Typically, the power batteries used in electric vehicles are composed of a large number of single cells connected in series and parallel. During the manufacturing process of the single cells, factors such as raw materials, manufacturing environment, manufacturing equipment, and manufacturing methods may change, which may lead to inconsistencies in performance such as capacity, voltage, and internal resistance between the single cells. In other words, there may be performance differences between the multiple single cells in the power battery. The amount of electricity ultimately output by the power battery is determined by the single cell with the worst performance among the multiple single cells. If there is a consistency problem between the multiple single cells of the power battery, the overall performance of the power battery will be affected. Moreover, if the consistency problem is not handled in a timely manner, it will directly reduce the life of the power battery. Based on this, a method is needed to test the consistency between multiple single cells of a power battery.

[0003] In related technologies, a vehicle's BMS (Battery Management System) monitors the voltages of all power battery cells and determines the difference between the maximum and minimum voltages within those cells. If this difference exceeds a preset maximum voltage difference, it is determined that there is a consistency issue among the power battery cells. However, this method cannot accurately describe the consistency of the power battery. Summary of the Invention

[0004] The present invention provides a method and apparatus for testing the consistency of a power battery, which can accurately describe the consistency of the power battery. The technical solution is as follows:

[0005] In one aspect, a consistency test method for a power battery is provided, wherein the power battery includes a plurality of single cells, and the method includes:

[0006] In response to a first acquisition instruction, acquiring a voltage of each of the plurality of single cells at a target charge state to obtain a plurality of first voltages corresponding one-to-one to the plurality of single cells, wherein the target charge state indicates that the power battery has a target power;

[0007] In response to a second acquisition instruction, acquiring a voltage of each of the plurality of single cells at the target state of charge to obtain a plurality of second voltages corresponding one-to-one to the plurality of single cells, wherein a duration between a triggering time of the second acquisition instruction and a triggering time of the first acquisition instruction exceeds a reference duration;

[0008] Based on the plurality of first voltages and the plurality of second voltages, consistency among the plurality of battery cells is tested.

[0009] Optionally, the testing the consistency between the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages includes:

[0010] determining a voltage consistency value for each of the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages, the voltage consistency value indicating a degree of consistency between the corresponding battery cell and the other battery cells;

[0011] For any single cell among the plurality of single cells, if the voltage consistency value of the single cell exceeds a reference consistency value, it is determined that there is a consistency problem among the plurality of single cells.

[0012] Optionally, the method further includes:

[0013] If the voltage consistency level value of each of the plurality of battery cells is lower than the reference level value, it is determined that there is no consistency problem between the plurality of battery cells.

[0014] Optionally, determining the voltage consistency value of each single cell in the plurality of single cells based on the plurality of first voltages and the plurality of second voltages includes:

[0015] determining a first voltage average based on the plurality of first voltages;

[0016] determining a second voltage average based on the plurality of second voltages;

[0017] For any single cell among the plurality of single cells, a voltage consistency value of the single cell is determined based on the first voltage and the second voltage of the single cell, and the first voltage average and the second voltage average.

[0018] Optionally, determining the voltage consistency value of any single cell based on the first voltage and the second voltage of any single cell, and the first voltage average and the second voltage average, includes:

[0019] Taking the first voltage of any single battery and the first voltage average as a quotient to obtain a first quotient value;

[0020] Taking the second voltage of any single battery and the second voltage average as a quotient to obtain a second quotient value;

[0021] A difference between the first quotient value and the second quotient value is determined as a voltage consistency value of the any one single battery.

[0022] Optionally, the target charge state includes a target charging state, and the target charging state indicates that the power battery is charged to the target power;

[0023] The determining a first voltage average based on the plurality of first voltages includes:

[0024] determining a maximum first voltage among the plurality of first voltages;

[0025] The first voltages other than the maximum first voltage are added together, and the added value is divided by an effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

[0026] Optionally, the target charge state includes a target discharge state, and the target discharge state indicates that the power battery is discharged to the target power;

[0027] The determining a first voltage average based on the plurality of first voltages includes:

[0028] determining a minimum first voltage among the plurality of first voltages;

[0029] The first voltages other than the minimum first voltage are added together, and the added value is divided by the effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

[0030] Optionally, before obtaining the voltage of each single cell in the plurality of single cells at the target state of charge, the method further includes:

[0031] controlling the power battery to be in the target state of charge;

[0032] After the duration of time that the power battery is in the target state of charge reaches a target duration, an operation of obtaining the voltage of each of the plurality of single cells in the target state of charge is performed.

[0033] Optionally, the power battery is installed on a vehicle, and the first acquisition instruction and the second acquisition instruction are triggered when the vehicle is in a target vehicle state, and the target vehicle state indicates an operating state of the vehicle.

[0034] In another aspect, a consistency test device for a power battery is provided, wherein the power battery includes a plurality of single cells, and the device includes:

[0035] a first acquisition module, configured to acquire, in response to a first acquisition instruction, a voltage of each of the plurality of single cells in a target state of charge, to obtain a plurality of first voltages corresponding one-to-one to the plurality of single cells, wherein the target state of charge indicates that the power battery has a target power level;

[0036] a second acquisition module, configured to acquire, in response to a second acquisition instruction, a voltage of each of the plurality of single cells at the target state of charge, to obtain a plurality of second voltages corresponding one-to-one to the plurality of single cells, wherein a duration between a triggering time of the second acquisition instruction and a triggering time of the first acquisition instruction exceeds a reference duration;

[0037] The testing module is configured to test the consistency between the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages.

[0038] Optionally, the test module includes:

[0039] a first determining submodule, configured to determine a voltage consistency value of each battery cell in the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages, the voltage consistency value indicating a degree of consistency between the corresponding battery cell and the other battery cells;

[0040] The second determining submodule is configured to determine, for any single cell among the multiple single cells, that a consistency problem exists among the multiple single cells if the voltage consistency value of the single cell exceeds a reference consistency value.

[0041] Optionally, the test module further includes:

[0042] The third testing submodule is configured to determine that there is no consistency problem between the plurality of single cells if the voltage consistency value of each single cell in the plurality of single cells is lower than the reference consistency value.

[0043] Optionally, the first determining submodule includes:

[0044] a first determining unit, configured to determine a first voltage average based on the plurality of first voltages;

[0045] a second determining unit, configured to determine a second voltage average based on the plurality of second voltages;

[0046] The third determining unit is configured to determine, for any single cell among the plurality of single cells, a voltage consistency value of the single cell based on the first voltage and the second voltage of the single cell and the first voltage average and the second voltage average of the single cell.

[0047] Optionally, the third determining unit is configured to:

[0048] Taking the first voltage of any single battery and the first voltage average as a quotient to obtain a first quotient value;

[0049] Taking the second voltage of any single battery and the second voltage average as a quotient to obtain a second quotient value;

[0050] A difference between the first quotient value and the second quotient value is determined as a voltage consistency value of the any one single battery.

[0051] Optionally, the target charge state includes a target charging state, and the target charging state indicates that the power battery is charged to the target power;

[0052] The first determining unit is configured to:

[0053] determining a maximum first voltage among the plurality of first voltages;

[0054] The first voltages other than the maximum first voltage are added together, and the added value is divided by an effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

[0055] Optionally, the target charge state includes a target discharge state, and the target discharge state indicates that the power battery is discharged to the target power;

[0056] The first determining unit is configured to:

[0057] determining a minimum first voltage among the plurality of first voltages;

[0058] The first voltages other than the minimum first voltage are added together, and the added value is divided by the effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

[0059] Optionally, the device further comprises:

[0060] a control module, configured to control the power battery to be in the target state of charge;

[0061] The execution module is configured to execute an operation of obtaining the voltage of each single cell of the plurality of single cells in the target state of charge after the duration for which the power battery is in the target state of charge reaches a target duration.

[0062] Optionally, the power battery is installed on a vehicle, and the first acquisition instruction and the second acquisition instruction are triggered when the vehicle is in a target vehicle state, and the target vehicle state indicates an operating state of the vehicle.

[0063] On the other hand, a computer device is provided, which includes a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to implement the steps of the above-mentioned power battery consistency testing method.

[0064] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored in the storage medium. When the computer program is executed by a processor, the steps of the above-mentioned method for consistency testing of a power battery are implemented.

[0065] On the other hand, a computer program product comprising instructions is provided. When the instructions are executed on a computer, the computer is caused to execute the steps of the above-mentioned method for consistency testing of a power battery.

[0066] The technical solutions provided in the embodiments of the present application can at least bring the following beneficial effects:

[0067] In an embodiment of the present application, multiple first voltages and multiple second voltages are obtained by acquiring the voltage of each of multiple single cells at a target state of charge at different times. Based on the multiple first voltages and multiple second voltages, the consistency between the multiple single cells during this time period is tested. Compared to methods that test the consistency between multiple single cells at a specific moment and then describe the consistency of a power battery, the embodiment of the present application improves the accuracy of determining the consistency of a power battery by testing the consistency between multiple single cells over a period of time. This allows users to promptly address power batteries with consistency issues, thereby improving the reliability of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0069] Figure 1 This is a flow chart of a consistency testing method for a power battery provided in an embodiment of the present application;

[0070] Figure 2 This is a schematic diagram showing the corresponding relationship between the voltage and lighting of a single battery provided in an embodiment of the present application;

[0071] Figure 3 This is a flow chart of a consistency testing method for a power battery provided in an embodiment of the present application;

[0072] Figure 4 This is a schematic diagram of voltage consistency values ​​of multiple single cells provided in an embodiment of the present application;

[0073] Figure 5 Schematic diagram of the structure of a power battery consistency test device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0074] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0075] Before explaining in detail the consistency testing method for a power battery provided in an embodiment of the present application, the application scenario provided in an embodiment of the present application is first introduced.

[0076] Power batteries used in electric vehicles typically require multiple cells connected in series and parallel to achieve high voltage and capacity. Due to differences in manufacturing processes, the voltages of multiple cells may vary, which means that there may be consistency issues between the cells. When these cells have consistency issues, the overall performance of the power battery will be affected, accelerating the loss of the battery life. Therefore, during the use of power batteries, it is necessary to test the consistency of multiple cells to improve the reliability of the power battery.

[0077] Based on this, an embodiment of the present application provides a consistency testing method for a power battery, which tests the consistency between multiple single cells during this period by obtaining the voltage of each single cell in multiple single cells at a target charge state at different times.

[0078] Next, the consistency testing method of the power battery provided in the embodiment of the present application is explained in detail.

[0079] Figure 1 This is a flow chart of a method for testing the consistency of a power battery provided by an embodiment of the present application. This method is applied to a controller. Figure 1 , the method includes the following steps.

[0080] Step 101: In response to a first acquisition instruction, the voltage of each single cell in a plurality of single cells at a target charge state is acquired to obtain a plurality of first voltages corresponding one-to-one to the plurality of single cells, wherein the target charge state indicates that the power of the power battery is the target power.

[0081] The power battery is installed in a vehicle, which may also be equipped with a battery management system (BMS). The BMS collects the voltages of the battery's multiple cells in real time and sends the collected voltages to a controller. The controller then tests the battery's consistency based on subsequent steps.

[0082] Generally, when the power level of a single battery is within the range of 20%-95%, the voltage of the single battery is relatively stable. Figure 2 It is a schematic diagram of the correspondence between the voltage and the power of a single cell provided in an embodiment of the present application. The correspondence can be exemplified as a curve graph. The horizontal axis in the curve graph represents the power (SOC) of the single cell, and the vertical axis represents the voltage of the single cell, and the unit of voltage is volt (V). It can be seen from the curve graph that when the power of the single cell is in the range of 20%-95%, the voltage of the single cell remains stable and basically unchanged. When the power of the single cell is greater than 95% or less than 20%, the voltage of the single cell changes significantly. Therefore, the power of the single cell will affect the voltage of the single cell. If the voltage of the single cell obtained by the controller in step 101 is affected by its own power, this will result in a large difference in the voltage changes of the single cell obtained twice, which will ultimately affect the consistency evaluation results of the power battery.

[0083] Based on this, to avoid the impact of individual battery voltage variations on the determination of power battery consistency, embodiments of the present application can obtain the voltage of each of the multiple battery cells at a target state of charge. In other words, the voltage of the multiple battery cells is obtained when the power battery's capacity is the target capacity. This allows the power battery voltage to remain within a relatively stable range. For example, the target capacity can be 20%-95%.

[0084] For example, a user can trigger a first acquisition instruction through a preset operation. The controller determines the current state of charge of the power battery, that is, the current power level of the power battery. When the current power level of the power battery is determined to be at the target level, a voltage acquisition request is sent to the BMS. Upon receiving the voltage acquisition request, the BMS transmits the voltages of multiple single cells at the target state of charge to the controller. The controller then obtains multiple first voltages corresponding to the multiple single cells.

[0085] In addition, if the current power level of the power battery is lower than the target power level, the controller can control the power battery to charge to the target power level, and then obtain the voltage of multiple single cells at the target power level based on the BMS system.

[0086] Based on this, in some embodiments, the target state of charge in step 101 may include a target charging state, which indicates that the power battery is charged to a target power level.

[0087] For example, a user can trigger a first acquisition instruction through a preset operation, and the controller determines the current power level of the power battery. If the current power level is determined to be lower than the target power level, the controller controls the power battery to charge to the target power level (target charge state). Then, when the power battery is in the target charge state, a voltage acquisition request is sent to the BMS system. When the BMS system receives the voltage acquisition request, it sends the voltages of multiple single cells in the target charge state to the controller. The controller can then obtain multiple first voltages corresponding to the multiple single cells.

[0088] For example, if the target power level is 50% and the current power level of the power battery is 20%, the controller controls the power battery to be charged to 50%. When it is determined that the power battery is charged to the target power level, that is, when the power battery is in the target charging state, the controller obtains the voltages of multiple single cells in the target charging state to obtain multiple first voltages.

[0089] In addition, if the current power level of the power battery exceeds the target power level, the controller can control the power battery to discharge to the target power level, and then obtain the voltage of multiple single cells at the target power level based on the BMS system.

[0090] Based on this, in some embodiments, the target state of charge in step 101 may include a target state of discharge, where the target state of discharge indicates that the power battery is discharged to a target power level.

[0091] For example, a user can trigger a first acquisition instruction through a preset operation, and the controller determines the current power battery charge. When it is determined that the current power battery charge exceeds the target power charge, the controller controls the power battery to discharge to the target power charge (target discharge state). Then, when the power battery is in the target discharge state, a voltage acquisition request is sent to the BMS system. When the BMS system receives the voltage acquisition request, it sends the voltages of multiple single cells in the target discharge state to the controller. The controller can then obtain multiple first voltages corresponding to the multiple single cells.

[0092] For example, if the target power level is 50% and the current power level of the power battery is 90%, the controller controls the power battery to discharge to 50%. When it is determined that the power battery has discharged to the target power level, that is, when the power battery is in the target discharge state, the controller obtains the voltages of multiple single cells in the target discharge state to obtain multiple first voltages.

[0093] Furthermore, the temperature of the power battery can also affect its voltage. When charging or discharging to the target charge, the battery's temperature may rise. Directly acquiring the voltages of multiple individual cells at this time may affect the temperature, thus impacting the consistency assessment of the power battery. Therefore, to avoid this, after charging or discharging, allow the power battery to rest for a period of time to allow the temperature to return to normal. Then, acquire the voltages of the individual cells after the temperature has returned to normal.

[0094] Based on this, in an embodiment of the present application, after the power battery has been in the target state of charge for a target duration, the voltage of each of the multiple single cells in the target state of charge can be obtained to obtain multiple first voltages. The target duration can be pre-set, and the target duration can be 30 minutes, for example.

[0095] In addition, the power battery is installed on the vehicle, and the embodiment of the present application can also test the consistency of the power battery when the vehicle is in different operating states based on the operating state of the vehicle.

[0096] Based on this, the first acquisition instruction in the embodiment of the present application can be triggered when the vehicle is in a target vehicle state, and the target vehicle state indicates the operating state of the vehicle.

[0097] For example, the target vehicle state is a stopped state. When the vehicle is stopped, a user triggers a first acquisition instruction through a preset operation, and the controller responds to the first acquisition instruction to acquire the voltage of each of the plurality of battery cells at the target state of charge to obtain a plurality of first voltages.

[0098] For example, the power battery includes 106 cells. The target state of charge is to discharge the power battery to 70% of the target charge. The target duration is 30 minutes. The controller can control the power battery to discharge to 70%, and after the power battery is at the target charge of 70% for 30 minutes, obtain the first voltage V of the 106 cells. 01 -V 0106 The first voltages of the 106 single cells are shown in Table 1 below. Table 1 lists the first voltages of some single cells by way of example.

[0099] Table 1

[0100]

[0101] Step 102: In response to a second acquisition instruction, the voltage of each single cell in the plurality of single cells at a target charge state is acquired to obtain a plurality of second voltages corresponding one-to-one to the plurality of single cells, and the duration between the triggering time of the second acquisition instruction and the triggering time of the first acquisition instruction exceeds a reference duration.

[0102] The reference time is the time difference between two acquisitions of the voltage of a single cell. The reference time may be, for example, one month or one year, etc., which is not limited in the embodiment of the present application.

[0103] Since the embodiment of the present application is to test the consistency between single cells over a period of time, the triggering time of the second acquisition instruction in step 102 is different from the triggering time of the first acquisition instruction in step 101. Otherwise, the operation of step 102 is identical to that of step 101. The implementation process of step 102 can refer to the relevant content of step 101 above and will not be repeated here.

[0104] It should be noted that the target charge state in step 102 is the same as the target charge state in step 101. For example, when the target charge state in step 101 is the target charging state, the charge state in step 102 is also the target charging state. When the target charge state in step 101 is the target discharging state, the charge state in step 102 is also the target discharging state.

[0105] In addition, if the first acquisition instruction in step 101 is triggered when the vehicle is in the target vehicle state, then the second acquisition instruction in step 102 is also triggered when the vehicle is in the target vehicle state, and the target vehicle state in step 102 is consistent with the target vehicle state in step 101. For example, if the first acquisition instruction in step 101 is triggered when the vehicle is in a stopped state, then the second acquisition instruction in step 102 is also triggered when the vehicle is in a stopped state.

[0106] For example, in step 101, the controller controls the power battery to discharge to 70%, and after the power battery is in the state of 70% of the target power for 30 minutes, the first voltage V of 106 single cells is obtained. 01 -V 0106 In the case of , the controller obtains the second voltage V of 106 single cells under the same conditions 11 -V 1106 The second voltages of the 106 single cells are shown in Table 2 below. Table 2 lists the second voltages of some single cells by way of example.

[0107] Table 2

[0108]

[0109] Step 103 : Testing the consistency between the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages.

[0110] In some embodiments, the implementation process of step 103 can be divided into the following steps. Step 1: Based on multiple first voltages and multiple second voltages, determine the voltage consistency value of each single cell in the multiple single cells, and the voltage consistency value indicates the degree of consistency between the corresponding single cell and other single cells. Step 2: For any single cell in the multiple single cells, if the voltage consistency value of any single cell exceeds the reference consistency value, it is determined that there is a consistency problem between the multiple single cells. Step 3: If the voltage consistency value of each single cell in the multiple single cells is lower than the reference consistency value, it is determined that there is no consistency problem between the multiple single cells.

[0111] The reference level value may be preset, and the reference level value may be empirically estimated based on the voltage consistency level value of each single battery, so as to determine whether there is a consistency problem between multiple single batteries.

[0112] In other words, based on the multiple first voltages and the multiple second voltages, a voltage consistency value is determined for each battery cell. If the voltage consistency value of a battery cell exceeds a reference value, it is determined that a consistency issue exists among the multiple batteries. If the voltage consistency value of each battery cell is lower than the reference value, it is determined that no consistency issue exists among the multiple batteries.

[0113] For example, the implementation process of step 1 can be divided into the following steps: Step 1: Determine an average of the first voltages based on the multiple first voltages. Step 2: Determine an average of the second voltages based on the multiple second voltages. Step 3: For any single cell in the multiple single cells, determine the voltage consistency value of the single cell based on the first and second voltages of the single cell, as well as the average of the first and second voltages.

[0114] Based on the description of step 101, the target state of charge may include a target charging state and a target discharging state. The following describes methods for determining a first voltage average based on multiple first voltages obtained from the target charging state and for determining a first voltage average based on multiple first voltages obtained from the target discharging state.

[0115] In a scenario where multiple first voltages are obtained based on a target state of charge, step 1 may be implemented by determining a maximum first voltage among the multiple first voltages, adding the first voltages other than the maximum first voltage, and dividing the sum by a valid number to obtain an average first voltage, where the valid number is the total number of the multiple first voltages minus one.

[0116] The first voltage mean reflects the central tendency of the multiple first voltages. During the charging process, the voltage increases, and the voltage of a single cell may be higher than the voltages of the other cells, i.e., extreme data occurs. If extreme data occurs among the multiple first voltages, the central tendency reflected by the first voltage mean calculated based on the multiple first voltages will be weakened. Therefore, to avoid the adverse effects of extreme data on the first voltage mean, in step 1, the largest first voltage among the multiple first voltages can be removed, and then the first voltage mean can be determined based on the remaining first voltages and the total number of the remaining first voltages.

[0117] For example, the power battery includes n single cells, and the n first voltages corresponding to the n single cells are V 01 、V 02 、V 03 ,…,V 0n The maximum first voltage among the n first voltages is V 0max Therefore, the first voltage mean value obtained based on step 1 can be expressed as: Among them, V 0ave represents the first voltage mean value.

[0118] In a scenario where multiple first voltages are obtained based on a target discharge state, step 1 may be implemented by determining a minimum first voltage among the multiple first voltages, adding the first voltages other than the minimum first voltage, and dividing the sum by a valid number to obtain an average first voltage, where the valid number is the total number of the multiple first voltages minus one.

[0119] During discharge, the voltage decreases, and the voltage of a single cell may be lower than that of the remaining cells, resulting in extreme data. If extreme data is present among the multiple first voltages, the central tendency reflected by the first voltage average calculated based on the multiple first voltages will be weakened. Therefore, to avoid the adverse effects of extreme data on the first voltage average, in step 1, the smallest first voltage among the multiple first voltages can be removed, and the first voltage average can then be determined based on the remaining first voltages and the total number of the remaining first voltages.

[0120] For example, the power battery includes n single cells, and the n first voltages corresponding to the n single cells are V 01 、V 02 、V 03 ,…,V 0n The minimum first voltage among the n first voltages is V 0min Therefore, the first voltage mean value obtained based on step 1 can be expressed as: Among them, V 0ave represents the first voltage mean value.

[0121] For example, for the 106 first voltages in Table 1, the minimum second voltage among the 106 first voltages is V 018 : 3.228V. Therefore, in the scenario where multiple first voltages are obtained based on the target discharge state, the average of the first voltages is

[0122] Optionally, the embodiment of the present application may also determine the first voltage mean directly based on the multiple first voltages and the total number of the multiple first voltages without considering the influence of extreme data on the first voltage mean.

[0123] For example, the power battery includes n single cells, and the n first voltages corresponding to the n single cells are V 01 、V 02 、V 03 ,…,V 0n The first voltage mean value can be expressed as: Among them, V 0ave represents the first voltage mean value.

[0124] After the first voltage average is determined based on step 1, step 2 may be performed: determining a second voltage average based on a plurality of second voltages.

[0125] Accordingly, the following describes methods for determining the second voltage average based on a plurality of second voltages obtained from the target charging state and for determining the second voltage average based on a plurality of second voltages obtained from the target discharging state.

[0126] In a scenario where multiple second voltages are obtained based on a target state of charge, step 2 may be implemented by determining a maximum second voltage among the multiple second voltages, adding the second voltages other than the maximum second voltage, and dividing the sum by a valid number to obtain an average second voltage, where the valid number is the total number of the multiple second voltages minus one.

[0127] For example, the power battery includes n single cells, and the n second voltages corresponding to the n single cells are V 11 、V 12 、V 13 ,…,V 1n The maximum second voltage among the n second voltages is V 1max Therefore, the second voltage mean value obtained based on step 2 can be expressed as: Among them, V 1ave represents the second voltage mean value.

[0128] In a scenario where multiple second voltages are obtained based on a target state of charge, step 2 may be implemented by determining a minimum second voltage among the multiple second voltages, adding the second voltages other than the minimum second voltage, and dividing the sum by a valid number to obtain an average second voltage, where the valid number is the total number of the multiple second voltages minus one.

[0129] For example, the power battery includes n single cells, and the n second voltages corresponding to the n single cells are V 11 、V 12 、V 13 ,…,V 1n The minimum second voltage among the n second voltages is V 1min Therefore, the second voltage mean value obtained based on step 1 can be expressed as: Among them, V 1ave represents the second voltage mean value.

[0130] For example, for the 106 second voltages in Table 2, the minimum second voltage among the 106 second voltages is V 199 : 3.239V. Therefore, in the scenario where multiple second voltages are obtained based on the target discharge state, the average second voltage is

[0131] Optionally, the embodiment of the present application may also determine the second voltage mean directly based on the multiple second voltages and the total number of the multiple second voltages without considering the influence of extreme data on the second voltage mean.

[0132] For example, the power battery includes n single cells, and the n second voltages corresponding to the n single cells are V 11 、V 12 、V 13 ,…,V 1n The second voltage mean can be expressed as: Among them, V 1ave represents the second voltage mean value.

[0133] After obtaining the first voltage average value based on step 1 and obtaining the second voltage average value based on step 2, the voltage consistency value of any single battery cell can be determined based on step 3.

[0134] For example, the implementation process of step 3 may be: taking the first voltage of any single cell and the average of the first voltage as the quotient to obtain a first quotient value, taking the second voltage of any single cell and the average of the second voltage as the quotient to obtain a second quotient value, and determining the difference between the first quotient value and the second quotient value as the voltage consistency value of any single cell.

[0135] For example, for the xth single cell, the first voltage of the xth single cell is V 0x , the first voltage average is V 0vae , the second voltage is V 1x , the second voltage average is V 1vae , then the voltage consistency value of the x-th single cell can be expressed as: Among them, S x Indicates the voltage consistency value of the x-th single cell.

[0136] Furthermore, because the voltage differences between multiple battery cells are minimal, the voltage consistency value determined using the above formula is very small. Therefore, to clearly reflect the voltage consistency value of each battery cell, the voltage consistency value obtained above can be magnified by a certain factor, so that the consistency between multiple battery cells can be determined based on the voltage consistency value of each battery cell. The certain factor can be, for example, 1000 times, and this is not limited in this embodiment of the present application.

[0137] The above step 3 is performed on each single cell to obtain the voltage consistency value of each single cell.

[0138] After obtaining the voltage consistency value of each battery cell, if the voltage consistency value of any battery cell among the plurality of batteries exceeds a reference value, it is determined that a consistency problem exists among the plurality of batteries. Alternatively, if the voltage consistency value of each battery cell among the plurality of batteries is lower than the reference value, it is determined that no consistency problem exists among the plurality of batteries.

[0139] The following will Figure 3 Taking the example of FIG. 1 as an example, the consistency testing method of the power battery provided in the embodiment of the present application is further explained.

[0140] Figure 3 This is a flow chart of a method for testing the consistency of a power battery provided by an embodiment of the present application. Figure 3 As shown, first, when the vehicle is in the target vehicle state, in response to a first acquisition instruction, the power battery is controlled to be in the target charge state. After the power battery has been in the target charge state for a target duration, the voltage of each of the multiple single cells in the target charge state is acquired, obtaining a plurality of first voltages corresponding one-to-one to the multiple single cells. Then, in response to a second acquisition instruction, the voltage of each of the multiple single cells in the target charge state is acquired, obtaining a plurality of second voltages corresponding one-to-one to the multiple single cells. It should be noted that the duration between the triggering time of the second acquisition instruction and the triggering event of the first acquisition instruction exceeds the reference duration.

[0141] After obtaining multiple first voltages and multiple second voltages, an average first voltage is determined based on the multiple first voltages. An average second voltage is determined based on the multiple second voltages. For each of the multiple battery cells, a voltage consistency value is determined for each battery cell based on the first and second voltages, as well as the average first and second voltages, to thereby obtain a voltage consistency value for each battery cell. The consistency between the multiple battery cells is then tested based on the voltage consistency value for each battery cell.

[0142] For example, after obtaining the 106 first voltages in Table 1, the 106 second voltages in Table 2, and the first voltage average value V 0ave =3.299V, and the second voltage average value V 1ave =3.345V, according to The voltage consistency value of each single cell in the 106 single cells is obtained. Figure 4 This is a schematic diagram of the voltage consistency values ​​of these 106 single cells.

[0143] The reference level value can be set to 10. Figure 4 As shown, the voltage consistency values ​​of the 106 cells, except for the 45th and 99th cells, remain essentially within a stable range. Furthermore, the voltage consistency values ​​of the remaining cells are all less than 10, with only the 45th and 99th cells exceeding 10. Therefore, it can be determined that there is a consistency issue among the 106 cells, and that the 45th and 99th cells are abnormal.

[0144] In an embodiment of the present application, multiple first voltages and multiple second voltages are obtained by acquiring the voltage of each of multiple single cells at a target state of charge at different times. Based on the multiple first voltages and multiple second voltages, the consistency between the multiple single cells during this time period is tested. Compared to methods that test the consistency between multiple single cells at a specific moment and then describe the consistency of a power battery, the embodiment of the present application improves the accuracy of determining the consistency of a power battery by testing the consistency between multiple single cells over a period of time. This allows users to promptly address power batteries with consistency issues, thereby improving the reliability of the power battery.

[0145] Figure 5 This is a schematic diagram of the structure of a power battery consistency test device provided by an embodiment of the present application. The device can be implemented by software, hardware, or a combination of both. Figure 5 The device includes: a first acquisition module 501, a second acquisition module 502 and a testing module 503.

[0146] The first acquisition module 501 is configured to obtain, in response to a first acquisition instruction, the voltage of each single cell in a plurality of single cells at a target charge state, and obtain a plurality of first voltages corresponding one-to-one to the plurality of single cells, wherein the target charge state indicates that the power level of the power battery is the target power level.

[0147] The second acquisition module 502 is used to respond to the second acquisition instruction, obtain the voltage of each single cell in the multiple single cells under the target charge state, and obtain multiple second voltages corresponding to the multiple single cells one by one. The duration between the triggering time of the second acquisition instruction and the triggering time of the first acquisition instruction exceeds the reference duration.

[0148] The testing module 503 is configured to test the consistency between the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages.

[0149] Optionally, the testing module 503 includes:

[0150] a first determining submodule, configured to determine a voltage consistency value of each single cell among the plurality of single cells based on the plurality of first voltages and the plurality of second voltages, the voltage consistency value indicating a degree of consistency between the corresponding single cell and the other single cells;

[0151] The second determining submodule is configured to determine that a consistency problem exists among the plurality of single cells if the voltage consistency value of any single cell among the plurality of single cells exceeds a reference consistency value.

[0152] Optionally, the testing module 503 further includes:

[0153] The third testing submodule is configured to determine that there is no consistency problem among the plurality of single cells if the voltage consistency value of each single cell in the plurality of single cells is lower than the reference consistency value.

[0154] Optionally, the first determining submodule includes:

[0155] A first determining unit, configured to determine a first voltage average based on the plurality of first voltages;

[0156] a second determining unit, configured to determine a second voltage average based on the plurality of second voltages;

[0157] The third determining unit is configured to determine, for any single cell among the plurality of single cells, a voltage consistency value of the single cell based on the first voltage and the second voltage, and the first voltage average and the second voltage average of the single cell.

[0158] Optionally, the third determining unit is configured to:

[0159] Taking the first voltage of any single battery and the first voltage average as a quotient to obtain a first quotient value;

[0160] Taking the second voltage of any single cell and the second voltage average as a quotient to obtain a second quotient value;

[0161] The difference between the first quotient value and the second quotient value is determined as the voltage consistency degree value of any single battery.

[0162] Optionally, the target state of charge includes a target charging state, the target charging state indicating that the power battery is charged to a target power level;

[0163] The first determining unit is configured to:

[0164] determining a maximum first voltage among a plurality of first voltages;

[0165] The first voltages except the maximum first voltage among the multiple first voltages are added together, and the added value is divided by the effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

[0166] Optionally, the target state of charge includes a target state of discharge, and the target state of discharge indicates discharging the power battery to a target power level;

[0167] The first determining unit is configured to:

[0168] determining a minimum first voltage among a plurality of first voltages;

[0169] The first voltages except the minimum first voltage are added together, and the added value is divided by the effective number to obtain the first voltage average, where the effective number is the total number of the first voltages minus one.

[0170] Optionally, the device further comprises:

[0171] A control module, used to control the power battery to be in a target state of charge;

[0172] The execution module is used to execute an operation of obtaining the voltage of each single cell in the plurality of single cells in the target charge state after the duration of time the power battery is in the target charge state reaches a target duration.

[0173] Optionally, the power battery is installed on the vehicle, and the first acquisition instruction and the second acquisition instruction are triggered when the vehicle is in a target vehicle state, and the target vehicle state indicates an operating state of the vehicle.

[0174] In an embodiment of the present application, multiple first voltages and multiple second voltages are obtained by acquiring the voltage of each of multiple single cells at a target state of charge at different times. Based on the multiple first voltages and multiple second voltages, the consistency between the multiple single cells during this time period is tested. Compared to methods that test the consistency between multiple single cells at a specific moment and then describe the consistency of a power battery, the embodiment of the present application improves the accuracy of determining the consistency of a power battery by testing the consistency between multiple single cells over a period of time. This allows users to promptly address power batteries with consistency issues, thereby improving the reliability of the power battery.

[0175] It should be noted that the power battery consistency test device provided in the above embodiment only uses the division of the above functional modules as an example to illustrate the consistency of the power battery. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the power battery consistency test device provided in the above embodiment and the power battery consistency test method embodiment are based on the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0176] In some embodiments, a computer-readable storage medium is further provided, which stores a computer program. When executed by a processor, the computer program implements the steps of the power battery consistency testing method in the above-mentioned embodiment. For example, the computer-readable storage medium may be a ROM, RAM, CD-ROM, magnetic tape, floppy disk, or optical data storage device.

[0177] It is worth noting that the computer-readable storage medium mentioned in the embodiments of the present application may be a non-volatile storage medium, in other words, a non-transitory storage medium.

[0178] It should be understood that all or part of the steps for implementing the above embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the steps may be implemented in the form of a computer program product. The computer program product may include one or more computer instructions. The computer instructions may be stored in the computer-readable storage medium.

[0179] That is, in some embodiments, a computer program product including instructions is further provided, which, when executed on a computer, enables the computer to execute the steps of the power battery consistency testing method described above.

[0180] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.) and signals involved in the embodiments of this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data need to comply with the relevant laws, regulations and standards of relevant countries and regions.

[0181] It should be understood that the "at least one" mentioned herein refers to one or more, and "a plurality of" refers to two or more. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0182] The above description is an embodiment provided for this application and is not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A consistency test method for a power battery, characterized in that: The power battery includes a plurality of single cells, and the method includes: In response to a first acquisition instruction, acquiring a voltage of each of the plurality of single cells at a target charge state to obtain a plurality of first voltages corresponding one-to-one to the plurality of single cells, wherein the target charge state indicates that the power battery has a target power; In response to a second acquisition instruction, acquiring a voltage of each of the plurality of single cells at the target state of charge to obtain a plurality of second voltages corresponding one-to-one to the plurality of single cells, wherein a duration between a triggering time of the second acquisition instruction and a triggering time of the first acquisition instruction exceeds a reference duration; Testing consistency among the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages includes: determining a voltage consistency value for each of the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages, the voltage consistency value indicating a degree of consistency between the corresponding battery cell and the other battery cells; For any single cell among the plurality of single cells, if the voltage consistency value of the single cell exceeds a reference consistency value, it is determined that there is a consistency problem among the plurality of single cells; The step of determining the voltage consistency value of each battery cell in the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages includes: determining a first voltage average based on the plurality of first voltages; determining a second voltage average based on the plurality of second voltages; For any single cell among the multiple single cells, a first quotient is obtained by taking the first voltage of the single cell and the average of the first voltages as a quotient; a second quotient is obtained by taking the second voltage of the single cell and the average of the second voltages as a quotient; and a difference between the first quotient and the second quotient is determined as the voltage consistency value of the single cell.

2. The method according to claim 1, wherein The method further comprises: If the voltage consistency level value of each of the plurality of battery cells is lower than the reference level value, it is determined that there is no consistency problem between the plurality of battery cells.

3. The method according to claim 1, wherein The target state of charge includes a target charging state, and the target charging state indicates that the power battery is charged to the target power; The determining a first voltage average based on the plurality of first voltages includes: determining a maximum first voltage among the plurality of first voltages; The first voltages other than the maximum first voltage are added together, and the added value is divided by an effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

4. The method according to claim 1, wherein The target charge state includes a target discharge state, and the target discharge state indicates that the power battery is discharged to the target power; The determining a first voltage average based on the plurality of first voltages includes: determining a minimum first voltage among the plurality of first voltages; The first voltages other than the minimum first voltage are added together, and the added value is divided by the effective number to obtain the first voltage average, where the effective number is the total number of the multiple first voltages minus one.

5. The method according to claim 1, wherein Before obtaining the voltage of each single cell in the plurality of single cells at the target state of charge, the method further includes: controlling the power battery to be in the target state of charge; After the duration of time that the power battery is in the target state of charge reaches a target duration, an operation of obtaining the voltage of each of the plurality of single cells in the target state of charge is performed.

6. The method according to claim 1, wherein The power battery is installed on a vehicle, and the first acquisition instruction and the second acquisition instruction are triggered when the vehicle is in a target vehicle state, where the target vehicle state indicates an operating state of the vehicle.

7. A consistency test device for a power battery, characterized in that: The power battery includes a plurality of single cells, and the device includes: a first acquisition module, configured to acquire, in response to a first acquisition instruction, a voltage of each of the plurality of single cells in a target state of charge, to obtain a plurality of first voltages corresponding one-to-one to the plurality of single cells, wherein the target state of charge indicates that the power battery has a target power level; a second acquisition module, configured to acquire, in response to a second acquisition instruction, a voltage of each of the plurality of single cells at the target state of charge, to obtain a plurality of second voltages corresponding one-to-one to the plurality of single cells, wherein a duration between a triggering time of the second acquisition instruction and a triggering time of the first acquisition instruction exceeds a reference duration; a testing module, configured to test consistency between the plurality of single cells based on the plurality of first voltages and the plurality of second voltages; Wherein, the test module includes: a first determining submodule, configured to determine a voltage consistency value of each battery cell in the plurality of battery cells based on the plurality of first voltages and the plurality of second voltages, the voltage consistency value indicating a degree of consistency between the corresponding battery cell and the other battery cells; a second determining submodule, configured to determine, for any single cell among the plurality of single cells, that a consistency problem exists between the plurality of single cells if the voltage consistency value of the single cell exceeds a reference consistency value; The first determining submodule includes: a first determining unit, configured to determine a first voltage average based on the plurality of first voltages; a second determining unit, configured to determine a second voltage average based on the plurality of second voltages; The third determination unit is used to, for any single cell among the multiple single cells, calculate the quotient of the first voltage of the any single cell and the average of the first voltage to obtain a first quotient value; calculate the quotient of the second voltage of the any single cell and the average of the second voltage to obtain a second quotient value; and determine the difference between the first quotient value and the second quotient value as the voltage consistency degree value of the any single cell.

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