Battery cell sampling wire breakage diagnosis method, device, equipment, storage medium and product

Abstract

The invention discloses a battery cell sampling wire breakage diagnosis method, device and equipment, a storage medium and a product, and relates to the technical field of batteries. The method comprises the following steps: acquiring sampling cell voltages of a plurality of cells at continuous N sampling moments under the condition of detecting the sudden change of current of a battery module; determining a voltage average value corresponding to each sampling moment in the N sampling moments based on the sampling cell voltages of the plurality of cells at the N sampling moments; based on the voltage average value corresponding to each sampling moment in the N sampling moments, calculating a voltage deviation value between the sampling cell voltage of the plurality of cells and the corresponding voltage average value at each sampling moment in the N sampling moments; and on the basis of the voltage deviation values of all the battery cells in the multiple battery cells at the N sampling moments, when it is detected that a target battery cell meeting a preset condition exists in the multiple battery cells, determining that the target battery cell is a battery cell with a broken sampling line. According to the embodiment of the invention, the disconnection diagnosis of the sampling wire of the battery cell can be simply and efficiently realized.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, device, equipment, storage medium, and product for diagnosing a broken battery cell sampling line. Background Art

[0002] With the rapid development of the new energy vehicle and energy storage markets, demand for batteries will continue to rise. A battery module is a unit composed of multiple battery cells connected in series, parallel, or series-parallel. A battery pack is composed of multiple battery modules connected in series. The main function of a battery module is to provide stable voltage and current output.

[0003] To ensure battery safety, the Battery Management System (BMS) monitors battery cells, including voltage monitoring, temperature monitoring, and current monitoring, to ensure that the battery operates within a safe range and prevent overcharging, over-discharging, and overheating. For example, the BMS needs to monitor the voltage of each cell based on the sampling line on the cell, make overcharge judgments based on the highest cell voltage, and make over-discharge judgments based on the lowest cell voltage. During BMS operation, if the cell sampling line is disconnected, the cell voltage will be inaccurately collected, and there is a risk of overcharging or over-discharging the cell voltage. In addition, inaccurate cell voltage collection will also affect the estimation of the battery's available capacity.

[0004] Therefore, during the battery management process, it is necessary to accurately and efficiently diagnose whether the battery cell sampling line is broken. Summary of the Invention

[0005] The embodiments of the present application provide a method, apparatus, device, storage medium, and product for diagnosing a cell sampling line break, which can simply and efficiently realize accurate diagnosis of a cell sampling line break.

[0006] In a first aspect, an embodiment of the present application provides a method for diagnosing a broken cell sampling line, the method comprising:

[0007] When a sudden change in the current of the battery module is detected, obtaining the sampled cell voltages of the multiple cells at N consecutive sampling moments, where the battery module includes multiple cells and N is a positive integer greater than 1;

[0008] Determine, based on the sampled cell voltages of the plurality of cells at N sampling moments, an average voltage value corresponding to each of the N sampling moments;

[0009] Calculate, based on the voltage average corresponding to each of the N sampling moments, a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average at each of the N sampling moments;

[0010] Based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, when it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells, it is determined that the target battery cell is a battery cell with a broken sampling line, wherein the preset condition is associated with the voltage deviation value.

[0011] In some possible implementations, based on voltage deviation values of each battery cell in the plurality of battery cells at N sampling moments, when a target battery cell that meets a preset condition is detected among the plurality of battery cells, determining that the target battery cell is a battery cell with a broken sampling line includes:

[0012] Determine, based on a voltage deviation value of each battery cell in the plurality of battery cells at N sampling moments, a change trend of the voltage deviation value of each battery cell at the N sampling moments;

[0013] Based on the change trend, when it is detected that a target cell that meets a preset condition exists among the multiple cells, it is determined that the target cell is a cell with a broken sampling line.

[0014] In some possible implementations, based on the comparison result and the change trend, when a target cell that meets a preset condition is detected among the multiple cells, determining that the target cell is a cell with a broken sampling line includes:

[0015] Based on the change trend, detect whether there is a target battery cell among the multiple battery cells that meets the following requirements: the change in the voltage deviation at N sampling moments exceeds a preset change range;

[0016] When it is detected that a change in the voltage deviation value of a target cell at N sampling moments among the multiple cells exceeds a preset change range, it is determined that the target cell is a cell with a broken sampling line.

[0017] In some possible implementations, after obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the cell sampling line disconnection diagnosis method further includes:

[0018] Determine, based on the sampled cell voltages of the plurality of cells at N sampling moments, a fluctuation value of the sampled cell voltage of each cell in the plurality of cells at the N sampling moments;

[0019] Based on voltage deviation values of each battery cell in a plurality of battery cells at N sampling moments, if a target battery cell that meets a preset condition exists among the plurality of battery cells, determining that the target battery cell is a battery cell with a broken sampling line includes:

[0020] Based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at N sampling moments, detecting whether there is a target battery cell in the multiple battery cells that meets the preset conditions;

[0021] When it is detected that a target cell exists among the multiple cells, the target cell is determined to be a cell with a broken sampling line, wherein the preset condition is associated with the voltage deviation value and the fluctuation value.

[0022] In some possible implementations, the preset condition includes a first preset sub-condition associated with the voltage deviation value, and a second preset sub-condition associated with the fluctuation value;

[0023] Based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at N sampling moments, detecting whether there is a target battery cell in the multiple battery cells that meets the preset conditions, including:

[0024] Based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at N sampling moments, detecting whether there is a target battery cell in the multiple battery cells that meets the first preset sub-condition and the second preset sub-condition;

[0025] The second preset sub-condition is that the fluctuation value of the sampled cell voltage at N sampling moments is less than a preset fluctuation threshold.

[0026] In some possible implementations, before obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the cell sampling line disconnection diagnosis method further includes:

[0027] Collect the battery current of the battery module according to the preset current sampling interval;

[0028] When the change amplitude of the first battery current compared to the second battery current is greater than the preset current amplitude, the current mutation of the battery module is determined, the first battery current is the most recently collected battery current, and the second battery current is the reference battery current.

[0029] In some possible implementations, collecting the battery current of the battery module according to a preset current sampling interval includes:

[0030] When the battery module starts charging, starts discharging, or increases the charging and discharging power, the battery current of the battery module is collected according to the preset current sampling interval.

[0031] Based on the same inventive concept, in a second aspect, an embodiment of the present application provides a cell sampling line breakage diagnosis device, the cell sampling line breakage diagnosis device comprising:

[0032] A first acquisition module is configured to acquire, when a sudden change in the current of the battery module is detected, sampled cell voltages of the plurality of cells at N consecutive sampling moments, where the battery module includes a plurality of cells, and N is a positive integer greater than 1;

[0033] A first determining module is configured to determine a voltage average value corresponding to each of the N sampling moments based on the sampled cell voltages of the plurality of cells at the N sampling moments;

[0034] A first calculation module is used to calculate a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average value at each of the N sampling moments based on the voltage average value corresponding to each of the N sampling moments;

[0035] The second determination module is used to determine that the target battery cell is a battery cell with a broken sampling line when it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, wherein the preset condition is associated with the voltage deviation value.

[0036] In a third aspect, an embodiment of the present application provides a cell sampling line disconnection diagnosis device, the cell sampling line disconnection diagnosis device comprising:

[0037] a processor and a memory storing computer program instructions;

[0038] When the processor executes the computer program instructions, the cell sampling line disconnection diagnosis method provided in any one of the above embodiments of the present application is implemented.

[0039] In a fourth aspect, an embodiment of the present application provides a computer storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, a method for diagnosing a cell sampling line breakage as provided in any one of the above embodiments of the present application is implemented.

[0040] In a fifth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the cell sampling line break diagnosis method provided in any one of the above embodiments of the present application.

[0041] From the above description, it can be seen that the embodiment of the present application is a method, device, equipment, storage medium and product for diagnosing a cell sampling line break. When a sudden change in the current of the battery module is detected, the sampled cell voltages of multiple cells at N consecutive sampling moments are obtained, and the voltage average value at different sampling moments is calculated based on the sampled cell voltages of the multiple cells. Then, the voltage deviation value between the sampled cell voltage of each cell at different sampling moments and the corresponding voltage average value is calculated based on the voltage average value. Finally, the cell sampling line break diagnosis is performed based on the voltage deviation values of the multiple cells at different sampling moments, so that the target cell of the sampling line break can be determined.

[0042] Compared with the related art, the embodiments of the present application provide a method, device, equipment, storage medium and product for diagnosing cell sampling line breakage, which can use the cell polarization effect to simply and efficiently implement cell sampling line breakage diagnosis by calculating the voltage deviation values of multiple cells at different sampling moments. This solution does not rely on the AFE chip model and the hardware sampling circuit topology, is suitable for various AFE chip sampling circuits, has strong applicability, and does not require the use of cell balancing for line break diagnosis, avoiding the increase in sampling error due to turning on balancing, and does not require the modification of the sampling circuit design to increase the cost of the single board. Overall, the embodiments of the present application provide a method, device, equipment, storage medium and product for diagnosing cell sampling line breakage, which can simply, efficiently and accurately implement cell sampling line breakage diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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 of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 This is a flow chart of a method for diagnosing a disconnection of a cell sampling line provided in one embodiment of the present application;

[0045] Figure 2 This is a structural diagram of an equivalent circuit model of a battery cell provided in one embodiment of the present application;

[0046] Figure 3 1 is a schematic diagram of a curve showing the change in cell voltage during startup charging provided by an embodiment of the present application;

[0047] Figure 4 1 is a schematic diagram of a curve showing the change in cell voltage during start-up discharge provided by an embodiment of the present application;

[0048] Figure 5 1 is a schematic diagram showing a trend of a voltage deviation value of a battery cell voltage changing over time provided by an embodiment of the present application;

[0049] Figure 6 This is a structural diagram of a battery sampling line disconnection diagnosis device provided in one embodiment of the present application;

[0050] Figure 7 It is a structural schematic diagram of a battery cell sampling line breakage diagnosis device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0051] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0052] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0053] It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned. They should be regarded as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0054] As mentioned in the background technology section, to ensure battery safety, the BMS currently monitors cell voltages using sampling lines on the cells. Overcharge is determined based on the highest cell voltage, and over-discharge is determined based on the lowest cell voltage. However, if the cell sampling line is disconnected, cell voltage data may be inaccurate, posing a risk to battery safety and management.

[0055] Specifically, a 48V battery module is typically made up of 16 battery cells connected in series, with each cell rated at approximately 3.2V. A 220V battery pack typically consists of four battery modules connected in series, with a total of 68 cells connected in series. For cell voltage acquisition, the industry's mainstream approach is to use an AFE (Analog Front-End Chip). The most widely used chips are ADI's ADBMS683x series, NXP's MC3377x series, and TI's BQ769x series. Each chip supports 13-18 cell voltage sampling, with a sampling accuracy of less than 5mV.

[0056] The AFE chips mentioned above all support disconnection diagnosis. However, the diagnostic solutions used by ADI, NXP, and TI vary and are deeply tied to the sampling circuit topology, making them complex and challenging to develop. For example, ADI's diagnostic solution connects a discharge circuit in parallel with each cell's sampling circuit. The discharge circuits of the odd and even channels are alternately closed, and the voltages before and after closing are measured and compared. If the voltage difference exceeds a threshold, the cell is considered disconnected. The development difficulty of this solution lies in determining the voltage difference threshold. Setting the threshold too low can easily lead to false alarms, while setting it too high can easily lead to missed detections. Furthermore, the probability of false alarms increases when the voltage drops below 2.5V. NXP and TI also face similar issues when diagnosing disconnected sampling lines. Furthermore, if the AFE chip model is changed, the disconnection detection solution needs to be redeveloped.

[0057] In addition, some solutions use balancing to perform cell sampling line diagnosis. However, during balancing, the cells may discharge a small current, which can affect normal voltage sampling and reduce sampling accuracy. Furthermore, some diagnostic methods require determining the number of sampling anomalies and the proximity of cell numbers. If all adjacent cell sampling lines are broken, the specific broken cell cannot be diagnosed, which also has many drawbacks.

[0058] In view of the above, the industry is still in urgent need of a battery cell sampling line break diagnosis solution that is independent of the AFE chip model and hardware sampling circuit topology, and is simpler, more efficient, and more applicable, so as to efficiently and accurately diagnose whether the battery cell sampling line is broken.

[0059] To solve the problems of the prior art, the embodiments of the present application provide a method, device, equipment, storage medium, and product for diagnosing a disconnection of a cell sampling line. It should be noted that the embodiments provided herein are not intended to limit the scope of the present application.

[0060] The following first introduces the method for diagnosing a broken cell sampling line provided in an embodiment of the present application.

[0061] Figure 1 A flow chart of a method for diagnosing a cell sampling line breakage provided in one embodiment of the present application is shown.

[0062] like Figure 1 As shown, the battery cell sampling line disconnection diagnosis method includes the following steps:

[0063] S110, when a sudden change in the current of the battery module is detected, obtaining sampled cell voltages of the plurality of cells at N consecutive sampling moments, where the battery module includes the plurality of cells, and N is a positive integer greater than 1;

[0064] S120, based on the sampled cell voltages of the plurality of cells at N sampling moments, determining a voltage average value corresponding to each of the N sampling moments;

[0065] S130, calculating, based on the voltage average value corresponding to each of the N sampling moments, a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average value at each of the N sampling moments;

[0066] S140, based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, in a case where it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells, determining that the target battery cell is a battery cell with a broken sampling line, wherein the preset condition is associated with the voltage deviation value.

[0067] From the above description, it can be seen that the embodiment of the present application is a method for diagnosing a cell sampling line break, which obtains the sampled cell voltages of multiple cells at N consecutive sampling moments when a sudden change in the current of the battery module is detected, and calculates the voltage average value at different sampling moments based on the sampled cell voltages of the multiple cells, and then calculates the voltage deviation value between the sampled cell voltage of each cell at different sampling moments and the corresponding voltage average value based on the voltage average value. Finally, the cell sampling line break diagnosis is performed based on the voltage deviation values of the multiple cells at different sampling moments, so that the target cell of the sampling line break can be determined.

[0068] Compared with the related art, the embodiment of the present application provides a method for diagnosing a cell sampling line break, which calculates the voltage deviation values of multiple cells at different sampling moments, thereby being able to use the cell polarization effect to simply and efficiently implement the cell sampling line break diagnosis. This solution does not rely on the AFE chip model and the hardware sampling circuit topology, is suitable for various AFE chip sampling circuits, has strong applicability, and does not require the use of cell balancing for line break diagnosis, thus avoiding the increase in sampling error due to turning on balancing, and also does not require the modification of the sampling circuit design to increase the cost of the single board. Overall, the embodiment of the present application provides a method for diagnosing a cell sampling line break, which can simply and efficiently implement the cell sampling line break diagnosis.

[0069] In order to facilitate understanding of the core concept of the present application, before describing in detail the specific implementation of the above steps 110 to 140, the implementation principle of the embodiment of the present application is first explained.

[0070] (1) Battery cell OCV

[0071] The cell's OCV (Open Circuit Voltage) refers to the voltage at the cell's terminals after the cell has been allowed to rest for an hour. This rest period is typically one hour, with no charging or discharging required to ensure accurate measurement results.

[0072] (2) Cell polarization effect

[0073] Cell polarization refers to a phenomenon in which the electrode surface deviates from its equilibrium state during the charge and discharge process. During charging, lithium ions are deintercalated from the positive electrode material and migrate toward the negative electrode. Due to factors such as the speed of lithium ion migration and the electrode reaction rate, charge accumulates on the electrode surface, resulting in polarization. For example, a large number of lithium ions accumulate on the negative electrode surface, waiting to be intercalated into the electrode material. This causes the electrode potential to deviate from its equilibrium potential. The opposite polarization phenomenon also occurs during discharge.

[0074] After careful research, the inventor of this application found that Figure 2 , Figure 2 Schematic diagram of the equivalent circuit model of a cell provided in one embodiment of the present application. Figure 2 As shown, the equivalent circuit model of the cell is established considering the polarization effect of the cell, U ocv Represents the static OCV of the battery cell, R0 represents the ohmic internal resistance of the battery cell, R1 represents the polarization internal resistance of the battery cell, C1 represents the polarization capacitance of the battery cell, i represents the current, and U represents the terminal voltage of the battery cell;

[0075] When the cell is at rest, the cell terminal voltage U is calculated as shown in the following formula (1):

[0076] U=U ocv (1)

[0077] When the cell is charging, the cell terminal voltage U is calculated as shown in the following formula (2):

[0078] U=U ocv +R0*i+U C1 (2)

[0079] When the cell is discharged, the cell terminal voltage U is calculated as shown in the following formula (3):

[0080] U=U ocv -R0*iU C1 (3)

[0081] See next Figure 3 , Figure 3 1 is a schematic diagram of a curve showing the change in cell voltage when starting charging according to an embodiment of the present application. Figure 3 As shown in the figure, when the battery starts charging, due to the action of the ohmic resistor R0, the battery voltage shows a first stage of instantaneous rise (time 14-16), and then a second stage of slow rise (time 16-20). The latter stage is caused by the charging and energy storage of the polarized capacitor C1. When the polarized capacitor C1 is fully charged, the battery voltage reaches a dynamic balance.

[0082] See Figure 4 , Figure 4 1 is a schematic diagram of a curve showing the change in cell voltage during start-up discharge provided by an embodiment of the present application. Figure 4 As shown, similarly, when the battery cell starts to discharge, due to the action of the ohmic resistor R0 and the polarized capacitor C1, the voltage shows a first stage of instantaneous drop (time 14-16), and then a second stage of slow drop (time 16-20). When the polarized capacitor C1 is fully charged, the battery cell voltage reaches dynamic equilibrium.

[0083] From the above research and analysis, it can be seen that when the charging and discharging current of the battery cell changes, the battery cell will experience a cell polarization effect, the voltage drop of the ohmic resistor R0 will change, and the polarized capacitor C1 will charge and store energy. The battery cell voltage will reach a dynamic balance after the changes in the above two stages occur.

[0084] In view of the above research and analysis, the embodiments of the present application make full use of the above-mentioned cell polarization effect when diagnosing the disconnection of the cell sampling line to accurately determine whether the cell sampling line is disconnected.

[0085] The above is the main implementation principle of the embodiment of the present application. Next, the specific implementation method of the above steps 110 to 140 will be described in detail.

[0086] In S110, the battery module includes multiple battery cells, which are connected in series, parallel, or a combination of series and parallel to form a battery module. Through a reasonable series and parallel design, the voltage and capacity requirements of different electrical devices can be met. The series connection can increase the battery module voltage, while the parallel connection can effectively increase the battery module capacity.

[0087] It should be added that when battery modules are grouped, cells with good voltage and capacity consistency from the same production batch can be used to group them, so that the characteristics of the cells are consistent and the voltage response at the charge and discharge ends is also consistent.

[0088] In order to facilitate the BMS to monitor the safety of battery cells in a timely manner, each cell in the battery module is usually provided with a cell sampling line. The sampling line can be set at the lug or end of the cell, or the sampling line can be connected through a flexible circuit board, which can be used to connect the sampling point of the cell and the BMS. In this application, the location and method of setting the cell sampling line need to be selected according to the specific application scenario and battery structure, and are not strictly limited here.

[0089] In specific implementations, the battery module current can be detected using methods such as Hall effect current sensors, mutual inductance current sensors, and digital current detection, with no strict restrictions here. By timely detecting current changes during battery module charging and discharging operations, the onset of the cell polarization effect can be determined.

[0090] In this step, when a sudden change in the current of the battery module is detected, the sampling lines of the respective battery cells are used to obtain the sampled battery cell voltages of the plurality of battery cells at N consecutive sampling moments.

[0091] For example, in a battery module comprising 16 cells connected in series, the AFE chip is used to measure the voltages of the 16 cells at N consecutive sampling times. During continuous sampling, the time interval between two adjacent sampling times is, for example, 10 ms, and the value of N is, for example, 5.

[0092] In S120 , in a specific implementation, based on the sampled cell voltages of the plurality of cells at N sampling moments, an average voltage value corresponding to each of the N sampling moments is determined.

[0093] For example, the sampled cell voltages of the plurality of cells collected at the first sampling moment are V11, V21 . . . Vn1, and the voltage average value Vave1 corresponding to the plurality of cells at the first sampling moment can be calculated through V11, V21 . . . Vn1.

[0094] The sampled cell voltages of the multiple cells collected at the second sampling moment are V12, V22...Vn2. The voltage average value Vave2 corresponding to the multiple cells at the second sampling moment can be calculated through V12, V22...Vn2.

[0095] By analogy, the voltage average values Vave1, Vave2, ..., VaveN corresponding to each of the N sampling moments can be calculated.

[0096] In S130 , in a specific implementation, based on the voltage average value corresponding to each of the N sampling moments, a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average value at each of the N sampling moments is calculated.

[0097] For example, the sampled cell voltages of the plurality of cells collected at the first sampling moment are V11, V21 . . . Vn1, and the voltage average value Vave1 corresponding to the plurality of cells at the first sampling moment can be calculated through V11, V21 . . . Vn1.

[0098] Next, based on the voltage average value Vave1 corresponding to the first sampling moment, voltage deviation values Vdiff11 , Vdiff21 . . . Vdiffn1 between the sampled cell voltages V11 , V21 . . . Vn1 of the plurality of cells at the first sampling moment and Vave1 are calculated.

[0099] The sampled cell voltages of the multiple cells collected at the second sampling moment are V12, V22...Vn2. The voltage average value Vave2 corresponding to the multiple cells at the second sampling moment can be calculated through V12, V22...Vn2.

[0100] Next, based on the corresponding voltage average value Vave2 at the second sampling moment, voltage deviation values Vdiff12, Vdiff22, ..., Vdiffn2 between the sampled cell voltages V12, V22, ..., Vn2 of the plurality of cells at the second sampling moment and Vave1 are calculated.

[0101] By analogy, the voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average value at each of the N sampling moments can be finally calculated.

[0102] In S140, during specific implementation, based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, when it is detected that there is a target battery cell that meets the preset conditions among the multiple battery cells, it is determined that the target battery cell is a battery cell with a broken sampling line, wherein the preset conditions are associated with the voltage deviation value.

[0103] In this embodiment, the cell polarization effect is used to diagnose the cell sampling line break based on the voltage deviation value of each cell in the multiple cells at N sampling moments. For example, the cell can be judged based on the size and change of the voltage deviation value of the cell at N sampling moments to determine whether the cell is in accordance with the following conditions: Figure 3 or Figure 4 The cell polarization effect is shown as the cell voltage change.

[0104] As an optional embodiment, S140, based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, when it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells, determines that the target battery cell is a battery cell with a broken sampling line, including:

[0105] Determine, based on a voltage deviation value of each battery cell in the plurality of battery cells at N sampling moments, a change trend of the voltage deviation value of each battery cell at the N sampling moments;

[0106] Based on the change trend, when it is detected that a target cell that meets a preset condition exists among the multiple cells, it is determined that the target cell is a cell with a broken sampling line.

[0107] In this embodiment, in order to fully ensure accurate cell sampling line disconnection diagnosis based on the voltage deviation value, whether there is a cell with a broken sampling line is detected according to the change trend of the voltage deviation value of each cell at N sampling moments.

[0108] Specifically, the voltage deviation values calculated for most cells with normal sampling lines are smaller than the average value, and the trend of voltage deviation value changes is relatively stable.

[0109] For a cell with a broken sampling line, the sampled cell voltage collected at N sampling moments is usually a fixed value. Depending on the fixed value and the battery's charge and discharge direction, the cell's voltage deviation may show a clear trend of gradually increasing, gradually decreasing, increasing first and then decreasing, or decreasing first and then increasing.

[0110] For example, if the voltage of a cell with a broken sampling line is 0V and the battery module starts charging, the sampling cell voltages of the remaining normal cells will increase over time, causing the calculated voltage average to gradually increase over time, thereby causing the voltage deviation between the broken cell and the corresponding voltage average to gradually expand.

[0111] For another example, if the fixed value is within the voltage variation range of a battery cell with a normal sampling line under polarization effect, with a fixed value of 3V, and the voltage variation range of a battery cell with a normal sampling line under polarization effect during charging is 2.5V to 3.5V, then the voltage deviation value of the broken battery cell will show an obvious trend of first decreasing and then increasing.

[0112] Based on this, by comparing the changing trends of the voltage deviation values in multiple battery cells, if it is determined that the voltage deviation value shows an obvious changing trend, it can be determined as the target battery cell with a broken sampling line.

[0113] As an optional embodiment, more specifically, based on the change trend, when a target cell that meets a preset condition is detected among multiple cells, determining that the target cell is a cell with a broken sampling line includes:

[0114] Based on the change trend, detect whether there is a target battery cell among the multiple battery cells that meets the following requirements: the change in the voltage deviation at N sampling moments exceeds a preset change range;

[0115] When it is detected that a change in the voltage deviation value of a target cell at N sampling moments among the multiple cells exceeds a preset change range, it is determined that the target cell is a cell with a broken sampling line.

[0116] It should be noted that the change in the voltage deviation of the above-mentioned battery cell at N sampling moments can be determined by the difference between the maximum and minimum values of the voltage deviation, or by calculating the root mean square (RMS), standard deviation, or variance of the voltage deviation of the battery cell, and no strict restrictions are imposed here.

[0117] The above-mentioned preset variation range is determined in advance based on actual simulation experience or testing, etc., to ensure the accuracy and reliability of judging whether the cell sampling line is broken based on the preset variation range.

[0118] In this embodiment, by judging whether the variation of the voltage deviation of the battery cell at N sampling moments exceeds a preset variation range, it is evaluated whether the variation trend of the voltage deviation value is stable or has significant fluctuations.

[0119] If the voltage deviation value of a target cell among multiple cells is detected to have changed beyond a preset range at N sampling moments, the target cell can be determined to have a broken sampling line. This approach, by leveraging the cell polarization effect and making a judgment based on the changing trend of the actual cell voltage deviation value, ultimately enables simple and efficient cell sampling line break diagnosis.

[0120] As an optional embodiment, after obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the cell sampling line disconnection diagnosis method further includes:

[0121] Determine, based on the sampled cell voltages of the plurality of cells at N sampling moments, a fluctuation value of the sampled cell voltage of each cell in the plurality of cells at the N sampling moments;

[0122] Based on voltage deviation values of each battery cell in a plurality of battery cells at N sampling moments, if a target battery cell that meets a preset condition exists among the plurality of battery cells, determining that the target battery cell is a battery cell with a broken sampling line includes:

[0123] Based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at N sampling moments, detecting whether there is a target battery cell in the multiple battery cells that meets the preset conditions;

[0124] When it is detected that a target cell exists among the multiple cells, the target cell is determined to be a cell with a broken sampling line, wherein the preset condition is associated with the voltage deviation value and the fluctuation value.

[0125] The fluctuation value of the sampled cell voltage of the above-mentioned battery cell at N sampling moments can be determined by the difference between the maximum and minimum values of the sampled cell voltage, or can be determined by calculating the root mean square value, standard deviation, or variance of the sampled cell voltage of the battery cell, etc., and is not strictly limited here. In this embodiment, considering the extremely small probability that the sampling lines of most of the multiple battery cells in the battery module may be broken. In order to ensure the reliability of the battery cell sampling line break diagnosis in this situation, the battery cell sampling line break diagnosis reliability is improved by introducing the fluctuation value of the sampled cell voltage of each battery cell at N sampling moments.

[0126] As an optional embodiment, more specifically, the preset condition includes a first preset sub-condition associated with the voltage deviation value, and a second preset sub-condition associated with the fluctuation value;

[0127] The above-mentioned detection of whether there is a target cell that meets the preset conditions in the multiple cells based on the voltage deviation value of each cell in the multiple cells at N sampling moments and the fluctuation value of the sampled cell voltage of each cell in the multiple cells at N sampling moments includes:

[0128] Based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at N sampling moments, detecting whether there is a target battery cell in the multiple battery cells that meets the first preset sub-condition and the second preset sub-condition;

[0129] The second preset sub-condition is that the fluctuation value of the sampled cell voltage at N sampling moments is less than a preset fluctuation threshold.

[0130] In this embodiment, the reliability of the cell sampling line disconnection diagnosis is improved by adding a judgment that the fluctuation value of the sampled cell voltage at N sampling moments is less than a preset fluctuation threshold.

[0131] Specifically, for cells with normal sampling lines, the cell voltage obtained by sampling will rise or fall over time; while for cells with broken sampling lines, the cell voltage obtained by sampling is often a relatively fixed value.

[0132] Therefore, if the target cell satisfies the first preset sub-condition related to the voltage deviation value, and at the same time satisfies the fluctuation value of the sampled cell voltage at N sampling moments is less than the preset fluctuation threshold, it can be fully ensured that the cell is the cell with a broken sampling line.

[0133] It should be understood that the first preset sub-condition here can refer to the relevant description of the voltage deviation value in the aforementioned embodiment, and will not be elaborated here.

[0134] As an optional embodiment, before obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the cell sampling line disconnection diagnosis method may further include:

[0135] Collect the battery current of the battery module according to the preset current sampling interval;

[0136] When the change amplitude of the first battery current compared to the second battery current is greater than the preset current amplitude, the current mutation of the battery module is determined, the first battery current is the most recently collected battery current, and the second battery current is the reference battery current.

[0137] The preset current sampling interval can be set based on actual detection requirements. For example, it can be 5ms. Furthermore, considering the short duration of the cell polarization effect, the current sampling interval can be set smaller to ensure that sufficient cell voltage sampling can be performed later to utilize the cell polarization effect for sampling line disconnection diagnosis.

[0138] The above-mentioned preset current amplitude is, for example, 10A, which can be flexibly set and selected according to the specific battery charging and discharging application scenario and battery module structure.

[0139] The second battery current may be a preset fixed battery current value, or the second battery current may be a battery current acquired at a previous acquisition moment compared to the first battery current, which is not strictly limited herein.

[0140] In this embodiment, the battery current of the battery module is collected according to a preset current sampling interval. When collecting the current of the battery module, Hall effect current sensor detection, mutual inductance current sensor detection, digital current detection and other methods can be used, and are not strictly limited here.

[0141] After obtaining the most recently acquired first battery current, it is compared with the second battery current to calculate the magnitude of the change in the first battery current relative to the second battery current. If the magnitude of the change is greater than a preset current magnitude, a sudden change in the battery module current is determined, indicating that the battery module may be in a state of startup charging or startup discharging.

[0142] In this case, normal cells will experience cell polarization. Therefore, when a sudden change in battery module current is detected, the battery voltage sampling phase for multiple subsequent cells begins.

[0143] In this way, through this embodiment, the rationality of current mutation detection can be fully guaranteed, thereby providing a good starting opportunity for subsequent cell sampling line break detection based on cell polarization effect, and ensuring the reliability and feasibility of the solution.

[0144] It should be understood that if the magnitude of the change in the first battery current compared to the second battery current is not greater than the preset current magnitude, the system can continue to wait for an updated first battery current and then compare the updated first battery current with the second battery current to detect whether a sudden current change has occurred. This cycle continues until a sudden current change is detected.

[0145] As an optional embodiment, collecting the battery current of the battery module according to a preset current sampling interval includes:

[0146] When the battery module starts charging, starts discharging, or increases the charging and discharging power, the battery current of the battery module is collected according to the preset current sampling interval.

[0147] In this embodiment, taking into account the actual scenarios where the cell polarization effect occurs, targeted current detection is performed when the battery module starts charging, starts discharging, or increases the charge and discharge power. Since the polarization phenomenon is most obvious in these situations, it can more accurately reflect the polarization characteristics of the cell. This helps to more accurately capture the cell voltage changes under polarization phenomena in the future, thus providing a basis for effective diagnosis of cell sampling line breakage in the battery module.

[0148] To facilitate understanding of the cell sampling line disconnection diagnosis method provided in the above embodiment, the above method is described below using a specific scenario embodiment. This scenario embodiment provides a cell sampling line disconnection diagnosis method based on polarization effect and voltage characteristic data, as follows:

[0149] Data sampling steps:

[0150] Step 1: Collect sampled cell voltages V1, V2, ..., Vn of multiple cells, calculate the average voltage value Vave corresponding to the sampling moment, and then calculate the voltage deviation value Vdiff between each sampled cell voltage and the average voltage value corresponding to the current sampling moment.

[0151] It should be added that when battery modules are grouped, cells with good voltage and capacity consistency from the same production batch are used to group them, so that the characteristics of the cells are consistent and the voltage response at the charge and discharge ends is also consistent.

[0152] Step 2: Store the sampled voltage deviation value Vdiff, wait for 10ms, return to step 1, and continue collecting cell voltage data.

[0153] Step 3: collect the sampled cell voltages of multiple cells every 10ms, calculate the voltage deviation value once, and finally store the relevant cell voltage and deviation value data obtained by the most recent sampling calculation.

[0154] Battery sampling line diagnostic steps:

[0155] Step 1: Determine whether the battery current of the battery module has a sudden change (starting charging, starting discharging, or increasing the charge / discharge power), and whether the current change amplitude exceeds 10A. If so, proceed to step 2; if not, wait 5ms before executing this step again.

[0156] Step 2: Wait for 50ms to collect and calculate 5 groups of voltage deviation values Vdiff of multiple cells at 10ms intervals.

[0157] Step 3: judge the voltage deviation value of each battery cell. If the voltage deviation values of the last five groups of a certain battery cell show a significant change trend, and the sampled battery cell voltage of the last five samplings of the battery cell does not change (the fluctuation value is within 5mV), it can be considered that the battery cell voltage sampling line is broken.

[0158] See below Figure 5 , Figure 5 3 is a schematic diagram showing a trend of a voltage deviation value of a battery cell voltage changing over time according to an embodiment of the present application. Figure 5 The figure shows the voltage deviation data of 16 cells in the battery module. Starting from 10ms charging, the cell voltage data is collected every 10ms and the corresponding voltage deviation value is calculated.

[0159] from Figure 5 In the data, we can observe that from 10ms to 50ms, the voltage deviation of cell 16 continues to increase, showing a significant upward trend. Meanwhile, the voltage deviations of the other cells change very little, remaining stable. Therefore, based on the changing trends of the voltage deviations of each cell at five consecutive sampling times, it can be determined that the sampling line for cell 16 is broken.

[0160] In this scenario, a method for diagnosing cell sampling line disconnection is provided. By calculating the voltage deviation values of multiple cells at different sampling times, the cell polarization effect can be utilized to simply and efficiently implement cell sampling line disconnection diagnosis. This solution is independent of the AFE chip model and hardware sampling circuit topology, and is suitable for various AFE chip sampling circuits. It has strong applicability and does not require the use of cell balancing for disconnection diagnosis, avoiding the increase in sampling error caused by enabling balancing. It also does not require modifying the sampling circuit design, which would increase the cost of the single board.

[0161] This solution is suitable for situations where battery cell polarization occurs during charge start-up, discharge start-up, and discharge stop, as well as situations where the battery operating current fluctuates. For example, in scenarios where the motor drive of a new energy electric vehicle accelerates or decelerates, the battery pack discharge current fluctuates significantly. This solution can fully utilize the cell polarization effect to achieve efficient and accurate cell sampling line disconnection diagnosis.

[0162] Based on the battery sampling line breakage diagnosis method provided in the above embodiment, for the same inventive concept, the present application also provides a battery sampling line breakage diagnosis device corresponding to the above battery sampling line breakage diagnosis method. Figure 6 A detailed introduction to the battery cell sampling line break diagnostic device is given.

[0163] Figure 6 A schematic structural diagram of a cell sampling line breakage diagnosis device provided in one embodiment of the present application is shown. Figure 6The battery cell sampling line breakage diagnosis device 600 shown includes:

[0164] A first acquisition module 610 is configured to acquire, when a sudden change in the current of the battery module is detected, sampled cell voltages of multiple cells at N consecutive sampling moments, where the battery module includes multiple cells and N is a positive integer greater than 1;

[0165] A first determining module 620 is configured to determine a voltage average corresponding to each of the N sampling moments based on the sampled cell voltages of the plurality of cells at the N sampling moments;

[0166] A first calculation module 630 is configured to calculate, based on the voltage average value corresponding to each of the N sampling moments, a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average value at each of the N sampling moments;

[0167] The second determination module 640 is used to determine that the target battery cell is a battery cell with a broken sampling line when it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, wherein the preset condition is associated with the voltage deviation value.

[0168] The present application provides a device for diagnosing a cell sampling line break. By configuring corresponding functional modules, the device obtains the sampled cell voltages of multiple cells at N consecutive sampling moments when a sudden change in the current of a battery module is detected. The device then calculates the average voltage at different sampling moments based on the sampled cell voltages of the multiple cells. The device then calculates the voltage deviation between the sampled cell voltages of each cell at different sampling moments and the corresponding average voltage based on the average voltage. Finally, the device performs a cell sampling line break diagnosis based on the voltage deviations of the multiple cells at different sampling moments, thereby identifying the target cell with a broken sampling line.

[0169] Compared with the related art, the embodiment of the present application provides a cell sampling line break diagnosis device, which calculates the voltage deviation values of multiple cells at different sampling moments, thereby being able to use the cell polarization effect to simply and efficiently implement cell sampling line break diagnosis. This solution does not rely on the AFE chip model and the hardware sampling circuit topology, is suitable for various AFE chip sampling circuits, has strong applicability, and does not require the use of cell balancing for line break diagnosis, thus avoiding the increase in sampling error due to turning on balancing, and also does not require the modification of the sampling circuit design to increase the cost of the single board. Overall, the cell sampling line break diagnosis method provided in the embodiment of the present application can simply and efficiently implement cell sampling line break diagnosis.

[0170] As an optional embodiment, the second determining module 640, based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments, determines that the target battery cell is a battery cell with a broken sampling line when a target battery cell that meets a preset condition is detected among the multiple battery cells. Specifically, the following steps may be performed:

[0171] The first determination submodule may be configured to determine a change trend of a voltage deviation value of each battery cell at N sampling moments based on the voltage deviation value of each battery cell in the plurality of battery cells at N sampling moments;

[0172] The second determining submodule may be configured to determine, based on a change trend, that the target cell is a cell with a broken sampling line when a target cell meeting a preset condition is detected among the multiple cells.

[0173] As an optional embodiment, the second determining submodule, based on the change trend, determines that the target cell is a cell with a broken sampling line when a target cell that meets a preset condition is detected among multiple cells. Specifically, the following may be included:

[0174] The first detection unit may be configured to detect, based on a change trend, whether a target battery cell among the plurality of battery cells satisfies: a change in a voltage deviation at N sampling moments exceeds a preset change range;

[0175] The first determining unit may be configured to determine that the target cell is a cell with a broken sampling line when it is detected that a change in the voltage deviation value of a target cell at N sampling moments among the multiple cells exceeds a preset change range.

[0176] As an optional embodiment, after obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the cell sampling line disconnection diagnosis device may further include:

[0177] A third determining module may be configured to determine a fluctuation value of a sampled cell voltage of each of the plurality of cells at N sampling moments based on the sampled cell voltages of the plurality of cells at N sampling moments;

[0178] The second determining module 640, based on the voltage deviation values of each battery cell in the multiple battery cells at N sampling moments, determines that the target battery cell is a battery cell with a broken sampling line when there is a target battery cell that meets the preset conditions among the multiple battery cells, and may include:

[0179] The first detection submodule can be used to detect whether there is a target battery cell that meets the preset conditions among the multiple battery cells based on the voltage deviation value of each battery cell in the multiple battery cells at N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at N sampling moments;

[0180] The third determination submodule may be configured to determine that the target cell is a cell with a broken sampling line when a target cell is detected among multiple cells, wherein the preset condition is associated with the voltage deviation value and the fluctuation value.

[0181] As an optional embodiment, the preset condition includes a first preset sub-condition associated with the voltage deviation value, and a second preset sub-condition associated with the fluctuation value;

[0182] The first detection submodule detects whether there is a target cell that meets preset conditions in the multiple cells based on the voltage deviation value of each cell in the multiple cells at N sampling moments and the fluctuation value of the sampled cell voltage of each cell in the multiple cells at N sampling moments, which may include:

[0183] The second detection unit may be configured to detect whether a target battery cell among the multiple battery cells satisfies the first preset sub-condition and the second preset sub-condition based on a voltage deviation value of each battery cell among the multiple battery cells at N sampling moments and a fluctuation value of a sampled battery cell voltage of each battery cell among the multiple battery cells at N sampling moments;

[0184] The second preset sub-condition is that the fluctuation value of the sampled cell voltage at N sampling moments is less than a preset fluctuation threshold.

[0185] As an optional embodiment, before obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the cell sampling line breakage diagnosis device may further include:

[0186] The first acquisition module can be used to collect the battery current of the battery module according to a preset current sampling interval;

[0187] The fourth determination module can be used to determine the current mutation of the battery module when the change amplitude of the first battery current compared to the second battery current is greater than the preset current amplitude, the first battery current is the most recently collected battery current, and the second battery current is the reference battery current.

[0188] As an optional embodiment, the first acquisition module may acquire the battery current of the battery module according to a preset current sampling interval, which may specifically include:

[0189] When the battery module starts charging, starts discharging, or increases the charging and discharging power, the battery current of the battery module is collected according to the preset current sampling interval.

[0190] Based on the battery sampling line breakage diagnosis method provided in the above embodiment, for the same inventive concept, the present application also provides a battery sampling line breakage diagnosis device corresponding to the above battery sampling line breakage diagnosis method. Figure 7 A detailed introduction to the battery sampling line break diagnostic equipment.

[0191] See below Figure 7 , Figure 7 It is a structural schematic diagram of a battery cell sampling line breakage diagnosis device provided in one embodiment of the present application.

[0192] The cell sampling line breakage diagnosis device may include a processor 701 and a memory 702 storing computer program instructions.

[0193] Specifically, the processor 701 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0194] The memory 702 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 702 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 702 may include removable or non-removable (or fixed) media. Where appropriate, the memory 702 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 702 is a non-volatile solid-state memory.

[0195] The memory may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical or other physical / tangible memory storage devices. Thus, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0196] The processor 701 reads and executes computer program instructions stored in the memory 702 to implement any one of the cell sampling line break diagnosis methods in the above embodiments.

[0197] In one example, the data cell sampling line disconnection diagnosis device may further include a communication interface 703 and a bus 710. Figure 7 As shown, the processor 701, the memory 702, and the communication interface 703 are connected via a bus 710 and communicate with each other.

[0198] The communication interface 703 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0199] Bus 710 includes hardware, software or both, and the components of the battery sampling line disconnection diagnostic equipment are coupled to each other. For example, and not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industry standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industry standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 710 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0200] The cell sampling line breakage diagnosis device executes the cell sampling line breakage diagnosis method in the embodiment of the present application, thereby realizing the cell sampling line breakage diagnosis method described in the embodiment of the present application.

[0201] In addition, in conjunction with the cell sampling line disconnection diagnosis method in the above-mentioned embodiment, the present application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any of the cell sampling line disconnection diagnosis methods in the above-mentioned embodiment is implemented.

[0202] Based on the cell sampling line break diagnosis method in the above-mentioned embodiment, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by the processor of an electronic device, the electronic device executes the cell sampling line break diagnosis method provided in any one of the above-mentioned embodiments of the present application.

[0203] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0204] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0205] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0206] Aspects of the present disclosure have been described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit. It is also understood that each box in the block diagram and / or flowchart and the combination of the boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0207] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the scope of protection of the present application.

Claims

1. A method for diagnosing a broken cell sampling line, characterized in that: The method comprises: When a sudden change in the current of the battery module is detected, obtaining sampled cell voltages of a plurality of cells at N consecutive sampling moments, where the battery module includes the plurality of cells, and N is a positive integer greater than 1; Determining, based on the sampled cell voltages of the multiple cells at the N sampling moments, a voltage average corresponding to each of the N sampling moments; Calculating, based on the voltage average corresponding to each of the N sampling moments, a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average at each of the N sampling moments; Based on the voltage deviation value of each battery cell in the multiple battery cells at the N sampling moments, when it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells, it is determined that the target battery cell is a battery cell with a broken sampling line, wherein the preset condition is associated with the voltage deviation value.

2. The method according to claim 1, characterized in that The method of determining, based on the voltage deviation values of each battery cell in the plurality of battery cells at the N sampling moments, that the target battery cell that meets a preset condition exists among the plurality of battery cells, that the target battery cell is a battery cell with a broken sampling line includes: Determining, based on the voltage deviation value of each battery cell in the plurality of battery cells at the N sampling moments, a change trend of the voltage deviation value of each battery cell at the N sampling moments; Based on the change trend, when it is detected that the target battery cell that meets the preset condition exists among the multiple battery cells, it is determined that the target battery cell is a battery cell with a broken sampling line.

3. The method according to claim 2, characterized in that The step of determining, based on the change trend, that the target cell that meets the preset condition exists among the plurality of cells, that the target cell is a cell with a broken sampling line includes: Based on the change trend, detecting whether the target battery cell among the multiple battery cells satisfies: a change in the voltage deviation at the N sampling moments exceeds a preset change range; When it is detected that a change in the voltage deviation of the target cell at the N sampling moments among the multiple cells exceeds the preset change range, the target cell is determined to be a cell with a broken sampling line.

4. The method according to claim 1, wherein After obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the method further includes: Determine, based on the sampled cell voltages of the multiple cells at the N sampling moments, a fluctuation value of the sampled cell voltage of each cell in the multiple cells at the N sampling moments; The method of determining, based on the voltage deviation values of each of the multiple battery cells at the N sampling moments, that the target battery cell is a battery cell with a broken sampling line when there is a target battery cell that meets a preset condition among the multiple battery cells, includes: Based on the voltage deviation value of each battery cell in the multiple battery cells at the N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at the N sampling moments, detecting whether there is the target battery cell in the multiple battery cells that meets the preset condition; When it is detected that the target cell exists in the plurality of cells, the target cell is determined to be a cell with a broken sampling line, wherein the preset condition is associated with the voltage deviation value and the fluctuation value.

5. The method according to claim 4, characterized in that The preset condition includes a first preset sub-condition associated with the voltage deviation value, and a second preset sub-condition associated with the fluctuation value; The detecting whether there is the target battery cell that meets the preset condition in the multiple battery cells based on the voltage deviation value of each battery cell in the multiple battery cells at the N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at the N sampling moments includes: Based on the voltage deviation value of each battery cell in the multiple battery cells at the N sampling moments and the fluctuation value of the sampled battery cell voltage of each battery cell in the multiple battery cells at the N sampling moments, detecting whether the target battery cell in the multiple battery cells satisfies the first preset sub-condition and the second preset sub-condition; The second preset sub-condition is that the fluctuation value of the sampled cell voltage at the N sampling moments is less than a preset fluctuation threshold.

6. The method according to claim 1, characterized in that Before obtaining the sampled cell voltages of the plurality of cells at N consecutive sampling moments, the method further includes: Collecting the battery current of the battery module according to a preset current sampling interval; When the change amplitude of the first battery current compared to the second battery current is greater than the preset current amplitude, the current mutation of the battery module is determined, the first battery current is the most recently collected battery current, and the second battery current is the reference battery current.

7. The method according to claim 6, characterized in that The collecting the battery current of the battery module according to the preset current sampling interval includes: When the battery module starts charging, starts discharging, or increases the charging and discharging power, the battery current of the battery module is collected according to the preset current sampling interval.

8. A battery sampling line disconnection diagnosis device, characterized in that: The device comprises: A first acquisition module is configured to acquire, when a sudden change in current of a battery module is detected, sampled cell voltages of a plurality of cells at N consecutive sampling moments, where the battery module includes the plurality of cells, and N is a positive integer greater than 1; A first determining module is configured to determine a voltage average value corresponding to each of the N sampling moments based on the sampled cell voltages of the multiple cells at the N sampling moments; A first calculation module is configured to calculate, based on the voltage average value corresponding to each of the N sampling moments, a voltage deviation value between the sampled cell voltages of the plurality of cells and the corresponding voltage average value at each of the N sampling moments; A second determination module is configured to determine, based on the voltage deviation values of each of the multiple battery cells at the N sampling moments, that the target battery cell is a battery cell with a broken sampling line when it is detected that there is a target battery cell that meets a preset condition among the multiple battery cells, wherein the preset condition is associated with the voltage deviation value.

9. A battery sampling line disconnection diagnosis device, characterized in that: The device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the method for diagnosing a cell sampling line breakage according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the method for diagnosing a broken cell sampling line according to any one of claims 1 to 7 is implemented.

11. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for diagnosing a broken cell sampling line according to any one of claims 1 to 7.

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