Method, device, equipment and medium for locating abnormal self-discharge of battery pack

Abstract

The present application provides a method, device, equipment and medium for locating abnormal self-discharge of a battery pack. The method includes determining a battery cell to be tested in the battery pack; detecting whether the grouping of the battery cell to be tested is abnormal to obtain a grouping detection result; and detecting whether the self-discharge of the battery cell to be tested is abnormal to obtain a battery detection result; and performing fault location of abnormal self-discharge of the battery pack according to the grouping detection result and the battery detection result. This solution is aimed at the battery pack scenario, comprehensively considering the grouping of battery cells and the self-discharge detection of battery cells, and can accurately judge the cause of abnormal self-discharge of the battery pack in the battery integration scenario and accurately locate the position causing the abnormality of the battery pack, so as to facilitate technicians to solve the fault.

Description

Technical Field

[0001] This application relates to the field of energy storage, and particularly to a method, device, equipment and medium for locating abnormal self-discharge of a battery pack. Background Art

[0002] The rapid application of electrochemical energy storage will inevitably bring some defects in aspects such as battery production and manufacturing, system integration, and application. For example, the introduction of impurities inside the battery monomer, and the introduction of metal particles between monomer batteries during the battery system integration process. These defects will externally show a low voltage of the monomer battery, that is, fast self-discharge, which will further affect the charge and discharge capacity of the entire system, and may even cause safety risks in severe cases.

[0003] Current self-discharge abnormality detection means, such as accelerating the chemical reaction and electrochemical corrosion reaction of metal foreign objects during the manufacturing process of battery monomers, and using the voltage change rate to quickly screen out abnormal battery cells; or adopting the principle of accelerating side reactions inside the battery at high temperature, screening out self-discharge abnormal batteries by measuring the open-circuit voltage, AC internal resistance and self-discharge rate, and then performing re-screening and final screening at room temperature, etc.

[0004] However, the above means cannot be applied to battery integration scenarios, such as the abnormality detection of battery packs. Summary of the Invention

[0005] This application provides a method, device, equipment and medium for locating abnormal self-discharge of a battery pack to achieve abnormal location in the battery integration scenario.

[0006] On the one hand, this application provides a method for locating abnormal self-discharge of a battery pack, including:

[0007] Determine the battery monomer to be tested in the battery pack;

[0008] Detect whether the grouping of the battery monomer to be tested is abnormal to obtain a grouping detection result; and detect whether the self-discharge of the battery monomer to be tested is abnormal to obtain a battery detection result;

[0009] According to the grouping detection result and the battery detection result, perform self-discharge abnormal fault location of the battery pack.

[0010] In one embodiment, the determining the battery monomer to be tested in the battery pack includes:

[0011] Obtain the voltage across each battery monomer in the battery pack;

[0012] If the voltage across the battery monomer is lower than the average voltage of the monomers in the module or there is a user-specified monomer battery, then use this battery monomer as the battery monomer to be tested.

[0013] In one embodiment, detecting whether the grouping of the battery cell to be measured is abnormal to obtain a grouping detection result includes:

[0014] Measuring the insulation resistance value between the housings of adjacent battery cells other than the battery cell to be measured in the battery pack as a standard value;

[0015] For each battery cell to be measured, measuring the insulation resistance between the battery cell to be measured and the housing of the adjacent battery cell;

[0016] If the insulation resistance between the battery cell to be measured and the adjacent battery cell is less than the standard value, it is determined that the grouping detection result of the battery cell to be measured is abnormal grouping.

[0017] In one embodiment, detecting whether the self-discharge of the battery cell to be measured is abnormal to obtain a battery detection result includes:

[0018] For the test battery pack composed of battery cells other than the battery cell to be measured in the battery pack, calculating the self-discharge rate of the test battery pack in multiple time periods;

[0019] Based on the self-discharge rate of the test battery pack in the multiple time periods, fitting to obtain a standard self-discharge curve;

[0020] For each battery cell to be measured, calculating the self-discharge rate of the battery cell to be measured;

[0021] By comparing the relative position of the self-discharge rate of the battery cell to be measured with the standard self-discharge curve, obtaining the battery detection result of the battery cell to be measured.

[0022] In one embodiment, for the test battery pack composed of battery cells other than the battery cell to be measured in the battery pack, calculating the self-discharge rate of the test battery pack in multiple time periods includes:

[0023] For the test battery pack composed of battery cells other than the battery cell to be measured in the battery pack, obtaining the static voltage of the test battery pack at multiple moments;

[0024] According to the static voltage of the test battery pack at the multiple moments, subtracting adjacent moments to obtain the duration of the corresponding time period; subtracting the static voltages at the adjacent moments to obtain the change value of the static voltage within the corresponding time period;

[0025] For each time period, calculating the ratio of the change value of the static voltage in the time period to the duration of the time period to obtain the self-discharge rate of the test battery pack in the multiple time periods.

[0026] In one embodiment, before calculating the self-discharge rate of each battery cell to be measured, the following steps are further included:

[0027] For each battery cell to be measured, disconnect the component formed between the battery cell to be measured and other battery cells;

[0028] Discharge the battery cell to be measured to the cut-off voltage, charge it to a predetermined power after standing, and then leave it to stand.

[0029] In one embodiment, obtaining the battery detection result of the battery cell to be measured by comparing the relative position of the self-discharge rate of the battery cell to be measured with the standard self-discharge curve includes:

[0030] If the position of the self-discharge rate of the battery cell to be measured in the coordinate system is above the standard self-discharge curve in this coordinate system, it is determined that the battery detection result of the battery cell to be measured is abnormal self-discharge.

[0031] On the other hand, the present application provides a positioning device for abnormal self-discharge of a battery pack, including:

[0032] A determination device, configured to determine the battery cell to be measured in the battery pack;

[0033] A detection device, configured to detect whether the grouping of the battery cell to be measured is abnormal to obtain a grouping detection result; and detect whether the self-discharge of the battery cell to be measured is abnormal to obtain a battery detection result;

[0034] A positioning device, configured to perform positioning of the abnormal self-discharge fault of the battery pack according to the grouping detection result and the battery detection result.

[0035] In one embodiment, the determination device is specifically configured to obtain the voltage across each battery cell in the battery pack;

[0036] The determination device is further specifically configured to, if the voltage across the battery cell is lower than the average voltage of the cells in the module or there is a single battery specified by the user, use this battery cell as the battery cell to be measured.

[0037] In one embodiment, the detection device is specifically configured to measure the insulation resistance value between the cases of adjacent battery cells other than the battery cell to be measured in the battery pack as a standard value;

[0038] The detection device is further specifically configured to, for each battery cell to be measured, measure the insulation resistance between the case of the battery cell to be measured and the case of the adjacent battery cell;

[0039] The detection device is specifically further configured to determine that the grouping detection result of the battery cell to be tested is abnormal in grouping if the insulation resistance between the battery cell to be tested and the adjacent battery cell is less than the standard value.

[0040] In one embodiment, the detection device is specifically further configured to calculate the self-discharge rate of the test battery pack formed by the battery cells other than the battery cell to be tested in the battery pack for multiple time periods.

[0041] The detection device is specifically further configured to obtain a standard self-discharge curve by fitting based on the self-discharge rate of the test battery pack in the multiple time periods.

[0042] The detection device is specifically further configured to calculate the self-discharge rate of each battery cell to be tested.

[0043] The detection device is specifically further configured to obtain the battery detection result of the battery cell to be tested by comparing the relative position of the self-discharge rate of the battery cell to be tested with the standard self-discharge curve.

[0044] In one embodiment, the detection device is specifically further configured to obtain the static voltage of the test battery pack formed by the battery cells other than the battery cell to be tested in the battery pack at multiple moments.

[0045] The detection device is specifically further configured to obtain the duration of the corresponding time period by taking the difference between adjacent moments according to the static voltage of the test battery pack at the multiple moments; take the difference between the static voltages at the adjacent moments to obtain the change value of the static voltage within the corresponding time period.

[0046] The detection device is specifically further configured to calculate the ratio of the change value of the static voltage in each time period to the duration of the time period for each time period to obtain the self-discharge rate of the test battery pack in the multiple time periods.

[0047] In one embodiment, the detection device is specifically further configured to disconnect the components between each battery cell to be tested and other battery cells.

[0048] The detection device is specifically further configured to discharge the battery cell to be tested to the cut-off voltage, charge it to a predetermined power after standing, and then set it aside.

[0049] In one embodiment, the detection device is specifically further configured to determine that the battery detection result of the battery cell to be tested is abnormal in self-discharge if the position of the self-discharge rate of the battery cell to be tested in the coordinate system is above the standard self-discharge curve in the coordinate system.

[0050] In another aspect, the present application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0051] The memory stores computer-executable instructions;

[0052] The processor executes the computer-executable instructions stored in the memory to implement the method as described above.

[0053] In another aspect, the present application provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the method as described above.

[0054] In the method, device, equipment and medium for locating abnormal self-discharge of the battery pack provided by the present application, by the voltage of each battery cell in the battery pack, the battery cell with a voltage lower than the rated voltage is determined as the battery cell to be tested; by detecting whether the grouping state between the battery cells connected to both sides of the battery cell to be tested is abnormal, and by detecting whether the self-discharge of the battery cell to be tested is abnormal, the abnormal self-discharge fault of the battery pack is located. This solution is for the battery pack scenario, comprehensively considering the grouping of battery cells and the self-discharge detection of battery cells, and can accurately judge the cause of abnormal self-discharge of the battery pack in the battery integration scenario, and accurately locate the position causing the abnormality of the battery pack, so as to facilitate technicians to solve the fault. Description of the Drawings

[0055] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0056] Figure 1 A topology diagram of a battery pack for example;

[0057] Figure 2 A flowchart showing the method for locating abnormal self-discharge of the battery pack provided in Embodiment 1 of the present application;

[0058] Figure 3 A standard self-discharge curve of a battery cell;

[0059] Figure 4 A comparison diagram of the self-discharge rate of the battery cell to be tested and the standard self-discharge curve of the battery cell;

[0060] Figure 5 A schematic structural diagram of the device for locating abnormal self-discharge of the battery pack provided in Embodiment 2 of the present application;

[0061] Figure 6 A schematic structural diagram of an electronic device provided in an embodiment of the present application;

[0062] Figure 7 A block diagram of a central control unit shown according to an exemplary embodiment.

[0063] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0064] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0065] It should be noted that the brief description of the terms in the present application is only for the convenience of understanding the implementation manners described next, rather than intending to limit the implementation manners of the present application. Unless otherwise specified, these terms should be understood in their ordinary and general meanings.

[0066] Currently, there are various ways of integrating batteries. For example Figure 1 For example, the topology diagram of a battery pack Figure 1 The battery pack in is composed of a plurality of battery cells connected in series and in parallel. The present application finds that any abnormal battery cell in the battery pack will cause abnormal self-discharge of the battery pack, and at the same time, abnormal grouping of the battery cells will also cause abnormal self-discharge of the battery pack. Therefore, it is crucial to accurately determine whether the cause of the abnormal self-discharge of the battery pack lies in the battery cells or the grouping between the battery cells, which requires accurately locating the position causing the abnormality of the battery pack, so as to facilitate technicians to solve the abnormal self-discharge of the battery pack.

[0067] The technical solution of the present application and the technical solution of the present application will be described in detail below with specific embodiments. These several specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. In the description of the present application, unless otherwise clearly specified and limited, each term should be understood in a broad sense in the art. The embodiments of the present application will be described below with reference to the drawings.

[0068] Embodiment 1

[0069] Figure 2 It is a schematic flow chart of a method for locating abnormal self-discharge of a battery pack provided in Embodiment 1 of the present application. As Figure 2 shown, the method includes:

[0070] Step 101: Determine the battery cell to be tested in the battery pack;

[0071] Step 102: Detect whether the grouping of the battery cell to be tested is abnormal to obtain a grouping detection result; and detect whether the self-discharge of the battery cell to be tested is abnormal to obtain a battery detection result;

[0072] Step 103: Locate the abnormal self-discharge fault of the battery pack according to the grouping detection result and the battery detection result.

[0073] Combined with a scenario example: A battery pack is generally composed of multiple battery cells integrated. Abnormalities in the battery cells themselves or the grouping between battery cells will cause abnormal self-discharge of the battery pack. For the situation of abnormal self-discharge in the battery pack, a suspected abnormal battery cell or abnormal range can be determined first to narrow the scope of investigation. Mark the suspected abnormal battery cell or abnormal range as the battery cell to be tested or the abnormal range to be tested. Subsequently, detect whether the grouping between the battery cell to be tested and the battery cells on both sides is abnormal, and detect whether the self-discharge of the battery cell to be tested is abnormal. Determine the cause and location of the abnormal self-discharge of the battery pack through the above two detection methods.

[0074] In one example, the determination of the battery cell to be tested in the battery pack includes:

[0075] Obtain the voltage across each battery cell in the battery pack;

[0076] If the voltage across the battery cell is lower than the average voltage of the cells in the module or there is a user-specified single cell, then use this battery cell as the battery cell to be tested.

[0077] Optionally, each battery cell constituting the battery pack has a static voltage. When it is found that the self-discharge of the battery pack is abnormal, the actual working voltage of each battery cell constituting the battery pack can be measured using a multimeter. If the measured actual working voltage of the battery cell is significantly lower than the average voltage of the cells in the module or there is a user-specified single cell, then the battery cell can be marked as a suspected abnormal battery cell for subsequent targeted measurement. Sometimes there is more than one abnormal battery cell. Therefore, if the working voltages of multiple battery cells are measured to be abnormal or suspected, then mark the multiple battery cells as abnormal battery cells or an abnormal range.

[0078] In one example, the detection of whether the grouping of the battery cell to be tested is abnormal to obtain a grouping detection result includes:

[0079] Measure the insulation resistance value between the cases of adjacent battery cells in the battery pack except the battery cell to be tested as the standard value;

[0080] For each of the battery cells to be tested, measure the insulation resistance between the battery cell to be tested and the housing of the adjacent battery cell;

[0081] If the insulation resistance between the battery cell to be tested and the adjacent battery cell is less than the standard value, it is determined that the grouping test result of the battery cell to be tested is abnormal in grouping.

[0082] Specifically, if the measured static voltage of the battery cell is less than the average voltage of the cells in the module or there is a battery cell specified by the user, it is marked as a suspected abnormal cell. The battery cell specified by the user refers to the battery cell that may be abnormal judged by the user based on actual experience, and the rest are normal battery cells. The voltage abnormality of the marked suspected abnormal cell may be due to the cell core problem of the battery cell itself, or it may be due to the problem in the grouping between the battery cell and the battery cells on both sides, resulting in the working voltage of the battery cell being less than the average voltage of the cells in the module, thereby causing abnormal self-discharge of the entire battery pack.

[0083] In order to more accurately determine the problem of abnormal self-discharge of the battery pack, it is necessary to not only detect whether the grouping between the marked suspected abnormal cell and the battery cells on both sides is abnormal, but also detect whether the self-discharge of the marked suspected abnormal cell itself is abnormal. Specifically, first use a multimeter to measure the insulation resistance value of the grouping between the housings of normal battery cells, and use the measured resistance value as the standard value of the insulation resistance of the grouping between the battery cell housings of the battery pack. Then, measure the insulation resistance value of the grouping between the marked suspected abnormal cell and the housings of the battery cells on both sides of it. If the measured insulation resistance value between the marked suspected abnormal cell and the housings of the battery cells on both sides of it is less than the measured standard value of the insulation resistance, it can be determined that the grouping between the marked suspected abnormal cell and the housings of the battery cells on both sides is abnormal, otherwise, it is considered that the grouping is normal.

[0084] In one example, detecting whether the self-discharge of the battery cell to be tested is abnormal and obtaining a battery detection result includes:

[0085] For the test battery pack composed of the battery cells in the battery pack except the battery cell to be tested, calculate the self-discharge rate of the test battery pack in multiple time periods;

[0086] Based on the self-discharge rates of the test battery pack in the multiple time periods, fit to obtain a standard self-discharge curve;

[0087] For each of the battery cells to be tested, calculate the self-discharge rate of the battery cell to be tested;

[0088] By comparing the self-discharge rate of the battery cell to be measured with the relative position of the standard self-discharge curve, the battery detection result of the battery cell to be measured is obtained.

[0089] After measuring the insulation resistance value of the group formed between the suspected abnormal cell marked and the battery cells on its both sides, if the measured resistance value is not less than the standard value of the insulation resistance, it is considered that there is no problem with the grouping between the suspected abnormal cell marked and the battery cells on its both sides, and it is necessary to further determine whether the self-discharge of the suspected abnormal cell marked is abnormal. If the measured resistance value is less than the standard value of the insulation resistance, it can be judged that there is a problem with the grouping between the suspected abnormal cell marked and the battery cells on its both sides, but it cannot be excluded that the suspected abnormal cell marked has no problem. Therefore, it is also necessary to further detect whether the self-discharge of the suspected abnormal cell marked itself is normal.

[0090] Optionally, disconnect the component group formed between the suspected abnormal cell marked and the battery cells on its both sides, so that a normally working battery pack is formed among other normal battery cells. Measure and calculate the self-discharge rate of the normally working battery pack at multiple moments, and fit it into a self-discharge curve. Take the self-discharge rate curve as the standard self-discharge curve of the battery cell. Then measure the self-discharge rate of each suspected abnormal battery cell marked, and compare the relative position of the standard self-discharge curve of the battery cell with the self-discharge rate of the suspected abnormal battery cell marked to obtain the detection result of the self-discharge rate of the suspected abnormal cell marked.

[0091] The standard self-discharge curve of the battery cell is a self-discharge curve fitted by calculating the self-discharge rate of a normally working battery pack at different moments. The fitting of the self-discharge curve can also be achieved by calculating the self-discharge rate of a normally working single battery cell. In actual measurement, even for normally working battery cells, there will be differences in the parameters between the battery cells. For example, different battery cell capacities may cause errors in the self-discharge curves fitted for different battery cells. Therefore, when fitting the standard self-discharge curve, the self-discharge rate of a normally working battery pack can be calculated to offset the errors caused by the differences in parameters between the battery cells.

[0092] In one example, calculating the self-discharge rate of the test battery pack composed of the battery cells in the battery pack except the battery cell to be measured within multiple time periods includes:

[0093] For the test battery pack composed of the battery cells in the battery pack except the battery cell to be measured, obtain the static voltage of the test battery pack at multiple moments;

[0094] According to the static voltages of the test battery pack at the multiple moments, find the difference between adjacent moments to obtain the duration of the corresponding time period; find the difference between the static voltages at the adjacent moments to obtain the change value of the static voltage within the corresponding time period.

[0095] For each time period, calculate the ratio of the change value of the static voltage in the time period to the duration of the time period to obtain the self-discharge rate of the test battery pack within the multiple time periods.

[0096] Specifically, to obtain the self-discharge rate of a normally operating battery pack within multiple time periods and fit it into a self-discharge curve, the normally operating battery pack needs to be placed for a period of time at a certain temperature and the static voltages at different moments are recorded. The temperature for placement can be selected as 20°C or above, and the placement time can be selected as 3 - 14 days. During this placement period, record the static voltages of the normally operating battery pack at different moments, obtain the self-discharge rate of the battery pack at different moments, and fit it into a self-discharge rate curve.

[0097] For example, in obtaining the self-discharge rate of the battery pack at different moments, different measurement moments can be recorded as: T1, T2, T3…Tx - 1, Tx, and the static voltages of the battery pack corresponding to the moments are: V1, V2, V3…Vx - 1, Vx. Then the calculation formula for the self-discharge rate K corresponding to the battery pack at the Tx moment is: K = (Vx - Vx - 1) / (Tx - Tx - 1). Using the formula for calculating the self-discharge rate K, the corresponding self-discharge rates at each moment can be obtained, and after fitting, the self-discharge curve of the battery pack is obtained and used as the self-discharge curve standard for a single battery cell, as Figure 3 shown, Figure 3 is the self-discharge curve standard for a single battery cell.

[0098] In one example, before calculating and obtaining the self-discharge rate of each of the battery monomers to be tested, it further includes:

[0099] For each of the battery monomers to be tested, disconnect the components between the battery monomer to be tested and other battery monomers;

[0100] Discharge the battery monomer to be tested to the cut-off voltage, charge it to a predetermined power after standing, and then place it.

[0101] After obtaining the self-discharge curve of the above battery cells standard, it is necessary to continue measuring the self-discharge rate of each marked and suspected abnormal battery cell. Specifically, for each battery cell to be measured, it is necessary to disconnect it from the battery cells on both sides in a group, discharge the marked battery cells to the cut-off voltage specified by the manufacturer at a small rate (optionally 0-1C), and then let it stand for a period of time, which can be 5 min - 2 h. After standing for a period of time, charge it at a small rate of 0-0.5C. If the battery cell is a lithium iron phosphate battery, the battery charge can be charged to 0-10% SOC. If the battery cell is a ternary battery, the battery charge is charged to 0-100% SOC, and then left to stand after charging is completed.

[0102] In one example, obtaining the battery detection result of the battery cell to be tested by comparing the relative position of the self-discharge rate of the battery cell to be tested with the standard self-discharge curve includes:

[0103] If the position of the self-discharge rate of the battery cell to be tested in the coordinate system is above the standard self-discharge curve in this coordinate system, it is determined that the battery detection result of the battery cell to be tested is self-discharge abnormal.

[0104] Specifically, during the process of the battery cell to be measured being left to stand, measure the corresponding static voltage at any two moments, calculate the self-discharge rate of the battery cell, and compare the measured self-discharge rate of the battery cell with the self-discharge curve of the standard battery cell. As Figure 4 shown, Figure 4 is a comparison chart of the self-discharge rate of the battery cell to be tested and the self-discharge curve of the standard battery cell. As shown in the figure, the positional relationship between the measured self-discharge rate of the battery cell and the self-discharge curve of the standard battery cell is approximately divided into three types, namely: above the curve (such as the position of point A); below the curve (such as the position of point C); exactly on the curve (such as the position of point B). If the measured self-discharge rate of the battery cell is at the position of point B or point C, it can be judged that the self-discharge of the measured battery cell is normal. However, if the measured self-discharge rate of the battery cell is at the position of point A, it indicates that the self-discharge of the measured battery cell is abnormal.

[0105] In this embodiment, by measuring the voltage across the battery cell, first determine the suspected abnormal battery cell or range and mark it, then measure the insulation resistance between the marked battery cell and the battery cell housings on both sides, and further measure the self-discharge rate of the marked battery cell to determine whether the self-discharge abnormality of the battery pack is due to the grouping between the battery cells or the problem of the battery cell itself. Through the above method, the reason for the self-discharge abnormality of the battery pack can be accurately judged, and the abnormal position can be accurately located, so as to facilitate the technical personnel to solve the self-discharge abnormality of the battery pack.

[0106] Example 2

[0107] Figure 5 The following is a schematic structural diagram of the positioning device for abnormal self-discharge of the battery pack provided in the second embodiment of the present application. As Figure 5 shown, the device includes:

[0108] A determination device 21, configured to determine a battery cell to be tested in the battery pack;

[0109] A detection device 22, configured to detect whether the grouping of the battery cell to be tested is abnormal to obtain a grouping detection result; and detect whether the self-discharge of the battery cell to be tested is abnormal to obtain a battery detection result;

[0110] A positioning device 23, configured to perform positioning of the abnormal self-discharge fault of the battery pack according to the grouping detection result and the battery detection result.

[0111] Combined with a scenario example: A battery pack is generally composed of multiple battery cells integrated. Abnormalities in the battery cells themselves or the grouping between the battery cells will cause abnormal self-discharge of the battery pack. For the situation of abnormal self-discharge of the battery pack, the determination device 21 can first determine a suspected abnormal battery cell or abnormal range to narrow the scope of investigation. Mark the suspected abnormal battery cell or abnormal range as the battery cell to be tested or the abnormal range to be tested. Subsequently, the detection device 22 detects whether the grouping between the battery cell to be tested and the battery cells on both sides is abnormal, and detects whether the self-discharge of the battery cell to be tested is abnormal. The positioning device 23 determines the cause and location of the abnormal self-discharge of the battery pack through the above two detection means.

[0112] The determination device 21 is specifically configured to obtain the voltage across each battery cell in the battery pack;

[0113] The determination device 21 is further specifically configured to use the battery cell as the battery cell to be tested if the voltage across the battery cell is lower than the average voltage of the cells in the module or there is a user-specified single battery cell.

[0114] Optionally, each battery cell that makes up the battery pack has its own static voltage. When it is found that the self-discharge of the battery pack is abnormal, the actual working voltage of each battery cell that makes up the battery pack can be measured using a multimeter. If the measured actual working voltage of the battery cell is significantly lower than the average voltage of the cells in the module or there is a user-specified single battery cell, the determination device 21 can mark the battery cell as a suspected abnormal battery cell for subsequent targeted measurement. Sometimes there is more than one abnormal battery cell. If the measured working voltages of multiple battery cells are abnormal or suspected, mark the multiple battery cells as abnormal battery cells or an abnormal range.

[0115] The detection device 22 is specifically configured to measure the insulation resistance value between the housings of adjacent battery monomers in the battery pack except for the battery monomer to be tested, as a standard value;

[0116] The detection device 22 is further specifically configured to measure the insulation resistance between each battery monomer to be tested and the housing of an adjacent battery monomer;

[0117] The detection device 22 is further specifically configured to determine that the grouping detection result of the battery monomer to be tested is abnormal if the insulation resistance between the battery monomer to be tested and the adjacent battery monomer is less than the standard value.

[0118] Specifically, if the static voltage of the battery monomer measured by the detection device 22 is lower than the average voltage of the monomers in the module or there is a user-specified monomer battery, it is marked as a suspected abnormal monomer. The user-specified monomer battery refers to the battery cells that the user judges may be abnormal based on actual experience. The rest are normal battery monomers. The voltage abnormality of the marked suspected abnormal monomer may be due to the problem of the battery core of the battery monomer itself, or it may be due to the problem of the grouping between the battery monomer and the battery monomers on both sides, resulting in the working voltage of the battery monomer being less than the average voltage of the monomers in the module, and never causing the self-discharge abnormality of the entire battery pack.

[0119] In order to more accurately determine the problem of self-discharge abnormality in the battery pack, the detection device 22 not only needs to detect whether the grouping between the marked suspected abnormal monomer and the battery monomers on both sides is abnormal, but also needs to detect whether the self-discharge of the marked suspected abnormal monomer itself is abnormal. Specifically, the insulation resistance value of the grouping between the housings of the normal battery monomers can be measured with a multimeter first, and the measured resistance value is used as the standard value of the insulation resistance of the grouping between the battery monomers of the battery pack. Then, the insulation resistance value of the grouping between the marked suspected abnormal monomer and the housings of the battery monomers on both sides is measured. If the measured insulation resistance value between the marked suspected abnormal monomer and the housings of the battery monomers on both sides is less than the measured insulation resistance standard value, it can be determined that the grouping between the marked suspected abnormal monomer and the housings of the battery monomers on both sides is abnormal; otherwise, it is considered that the grouping is normal.

[0120] The detection device 22 is further specifically configured to calculate the self-discharge rate of the test battery pack composed of battery monomers in the battery pack except for the battery monomer to be tested for multiple time periods;

[0121] The detection device 22 is further specifically configured to fit a standard self-discharge curve based on the self-discharge rate of the test battery pack for the multiple time periods;

[0122] The detection device 22 is further configured to calculate the self-discharge rate of each battery cell to be tested;

[0123] The detection device 22 is further specifically used to obtain the battery detection result of the battery cell to be tested by comparing the relative position of the self-discharge rate of the battery cell to be tested with the standard self-discharge curve.

[0124] After the detection device 22 measures the insulation resistance value of the group between the marked suspected abnormal cell and the battery cells on both sides thereof, if the measured resistance value is not less than the standard value of the insulation resistance, it is considered that there is no problem with the grouping between the marked suspected abnormal cell and the battery cells on both sides thereof, and it is necessary to further determine whether the self-discharge of the marked suspected abnormal cell is abnormal. If the measured resistance value is less than the standard value of the insulation resistance, it can be determined that there is a problem with the grouping between the marked suspected abnormal cell and the battery cells on both sides thereof, but it cannot be ruled out that there is no problem with the marked suspected abnormal cell, so it is also necessary to further detect whether the self-discharge of the marked suspected abnormal cell itself is normal.

[0125] Optionally, the assembly between the marked suspected abnormal cell and the battery cells on both sides thereof is disconnected, so that other normal battery cells form a normally functioning battery pack, and the detection device 22 measures and calculates the self-discharge rate of the normally functioning battery pack at multiple times, and fits it into a self-discharge curve, and uses the self-discharge rate curve as the standard self-discharge curve of the battery cell. The detection device 22 then measures the self-discharge rate of each marked suspected abnormal battery cell, and compares the relative position of the standard self-discharge curve of the battery cell with the self-discharge rate of the marked suspected abnormal battery cell, to obtain the detection result of the self-discharge rate of the marked suspected abnormal cell.

[0126] The standard self-discharge curve of the battery cell is fitted by calculating the self-discharge rate of a normally operating battery pack at different times. The fitting of the self-discharge curve can also be achieved by calculating the self-discharge rate of a normally operating single battery. In actual measurements, even for normally operating battery cells, there will be differences in parameters between the battery cells. For example, the difference in battery cell capacity may cause errors in the self-discharge curves fitted for different battery cells. Therefore, the self-discharge curve fitted to the standard can be calculated by calculating the self-discharge rate of a normally operating battery pack to offset the errors caused by the differences in parameters between battery cells.

[0127] The detection device 22 is further configured to obtain the static voltage of the test battery group at multiple moments for the test battery group composed of battery cells other than the battery cell to be tested in the battery group;

[0128] The detection device 22 is specifically further configured to obtain the duration of a corresponding time period by taking the difference between adjacent moments according to the static voltages of the test battery pack at the multiple moments; take the difference between the static voltages at the adjacent moments to obtain the change value of the static voltage within the corresponding time period;

[0129] The detection device 22 is specifically further configured to calculate, for each time period, the ratio of the change value of the static voltage in the time period to the duration of the time period to obtain the self-discharge rate of the test battery pack within the multiple time periods.

[0130] Specifically, for the detection device 22 to obtain the self-discharge rate of a normally operating battery pack within multiple time periods and fit it into a self-discharge curve, the normally operating battery pack needs to be placed for a period of time at a certain temperature, and the static voltages at different moments are recorded. The temperature for placement can be selected as 20 °C or above, and the placement time can be selected as 3 - 14 days. During this period of placement, the static voltages of the normally operating battery pack at different moments are recorded, the self-discharge rate of the battery pack at different moments is obtained, and it is fitted into a self-discharge rate curve.

[0131] For example, in the detection device 22 to obtain the self-discharge rate of the battery pack at different moments, different measurement moments can be recorded as: T1, T2, T3…Tx - 1, Tx, and the static voltages of the battery pack corresponding to the moments are: V1, V2, V3…Vx - 1, Vx. Then the calculation formula for the self-discharge rate K of the battery pack at the Tx moment is: K = (Vx - Vx - 1) / (Tx - Tx - 1). Using the formula for calculating the self-discharge rate K, the corresponding self-discharge rates at each moment can be obtained, and they are fitted to obtain the self-discharge curve of the battery pack, which is used as the self-discharge curve standard for a single battery cell, as Figure 3 shown, Figure 3 is the self-discharge curve standard for a single battery cell.

[0132] The detection device 22 is specifically further configured to disconnect the components formed between the battery cell to be tested and other battery cells for each battery cell to be tested;

[0133] The detection device 22 is specifically further configured to discharge the battery cell to be tested to the cut-off voltage, charge it to a predetermined power after standing, and then place it.

[0134] After obtaining the self-discharge curve of the above battery cells standard, the detection device 22 needs to continue to measure the self-discharge rate of each marked and suspected abnormal battery cell. Specifically, for each battery cell to be measured, it needs to be disconnected from the battery cells on both sides in groups, and the marked battery cells are discharged to the cut-off voltage specified by the manufacturer at a small rate (optionally 0-1C), and then left standing for a period of time, which can be 5 min - 2 h. After standing for a period of time, it is charged at a small rate of 0-0.5C. If the battery cell is a lithium iron phosphate battery, the battery charge can be charged to 0-10% SOC. If the battery cell is a ternary battery, the battery charge is charged to 0-100% SOC, and then left standing after charging is completed.

[0135] The detection device 22 is specifically further configured to determine that the battery detection result of the to-be-tested battery cell is self-discharge abnormal if the position of the self-discharge rate of the to-be-tested battery cell in the coordinate system is above the standard self-discharge curve in the coordinate system.

[0136] Specifically, during the process of leaving the battery cells to be measured standing, the static voltages are measured at any two moments, and the self-discharge rate of the battery cells is calculated. The positioning device 23 compares the measured self-discharge rate of the battery cells with the self-discharge curve of the standard battery cells. If the measured self-discharge rate of the battery cells is exactly at the point on the curve or at the position below the curve, it can be determined that the self-discharge of the measured battery cells is normal. However, if the measured self-discharge rate of the battery cells is at the position above the curve, it indicates that the self-discharge of the measured battery cells is abnormal.

[0137] In this embodiment, by measuring the voltages at both ends of the battery cells, the suspected abnormal battery cells or ranges are first determined and marked, and then the insulation resistance between the marked battery cells and the battery cell casings on both sides is measured, and the self-discharge rate of the marked battery cells is further measured to determine whether the self-discharge abnormality of the battery pack is due to the grouping between the battery cells or the problem of the battery cells themselves. Through the above method, the reason for the self-discharge abnormality of the battery pack can be accurately determined, and the abnormal position can be accurately located, so as to facilitate the technical personnel to solve the self-discharge abnormality of the battery pack.

[0138] Embodiment III

[0139] Figure 6 is a schematic structural diagram of an electronic device provided in an embodiment of the present application, as Figure 6 shown, the electronic device includes:

[0140] A processor 291, and the electronic device further includes a memory 292; it may also include a communication interface 293 and a bus 294. Among them, the processor 291, the memory 292, and the communication interface 293 can communicate with each other through the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can call the logical instructions in the memory 292 to execute the method of the foregoing embodiments.

[0141] In addition, when the logical instructions in the foregoing memory 292 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0142] The memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, that is, implements the methods in the foregoing method embodiments.

[0143] The memory 292 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 292 may include high-speed random access memory and may also include non-volatile memory.

[0144] The embodiments of the present application provide a non-transitory computer-readable storage medium, in which computer-execution instructions are stored, and when the computer-execution instructions are executed by a processor, they are used to implement the method as described in the foregoing embodiments.

[0145] Embodiment Four

[0146] Figure 7 It is a block diagram of a central control unit device shown according to an exemplary embodiment. The device can be a computer, a terminal, a messaging device, a tablet device, an operation console, etc. The device can be used to execute the grid connection control method described in the foregoing embodiments.

[0147] The device 800 may include one or more of the following components: a processing component 802, a memory 804, a power supply component 806, a multimedia component 808, an audio component 810, an input / output (I / O) interface 812, a sensor component 814, and a communication component 816.

[0148] The processing component 802 generally controls the overall operation of the device 800, such as operations associated with display, telephone calls, data communication, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to complete all or part of the steps of the above-described methods. In addition, the processing component 802 may include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0149] The memory 804 is configured to store various types of data to support the operation of the device 800. Examples of such data include instructions for any application or method operating on the device 800, contact data, phone book data, messages, pictures, videos, and the like. The memory 804 may be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0150] The power component 806 provides power to various components of the device 800. The power component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the device 800.

[0151] Optionally, the multimedia component 808 includes a screen that provides an output interface between the device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe actions but also detect the duration and pressure associated with the touch or swipe operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera may receive external multimedia data. Each of the front camera and the rear camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0152] Optionally, the audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC), which is configured to receive external audio signals when the device 800 is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals can be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, the audio component 810 further includes a speaker for outputting audio signals.

[0153] The I / O interface 812 provides an interface between the processing component 802 and a peripheral interface module, and the peripheral interface module can be a keyboard, a click wheel, buttons, etc. These buttons can include, but are not limited to: a home button, a volume button, a start button, and a lock button.

[0154] The sensor component 814 includes one or more sensors for providing status assessments of various aspects of the device 800. For example, the sensor component 814 can detect the on / off state of the device 800, the relative positioning of components, such as the display and keypad of the device 800. The sensor component 814 can also detect a change in the position of the device 800 or a component of the device 800, the presence or absence of user contact with the device 800, the orientation or acceleration / deceleration of the device 800, and the temperature change of the device 800. The sensor component 814 can include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor component 814 can also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor component 814 can further include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0155] The communication component 816 is configured to facilitate communication between the device 800 and other devices in a wired or wireless manner. The device 800 can access a wireless network based on a communication standard, such as WiFi, 2G, or 3G, or a combination thereof. In an exemplary embodiment, the communication component 816 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 further includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0156] In an exemplary embodiment, the apparatus 800 may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components for performing the above method.

[0157] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions, such as a memory 804 including instructions, is also provided. The above instructions may be executed by a processor 820 of the apparatus 800 to complete the above method. For example, the non-transitory computer-readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0158] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include common general knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and embodiments are only to be regarded as exemplary, and the true scope and spirit of the present application are pointed out by the following claims.

[0159] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A method for locating abnormal self-discharge of a battery pack, characterized in that, Including: Determine the battery cell to be tested in the battery pack; Detect whether the grouping of the battery cell to be tested is abnormal to obtain a grouping detection result; And detect whether the self-discharge of the battery cell to be tested is abnormal to obtain a battery detection result; Perform self-discharge abnormal fault location of the battery pack according to the grouping detection result and the battery detection result; The detecting whether the grouping of the battery cell to be tested is abnormal to obtain a grouping detection result includes: Measure the insulation resistance value between the cases of adjacent battery cells in the battery pack except the battery cell to be tested as a standard value; For each battery cell to be tested, measure the insulation resistance between the battery cell to be tested and the case of the adjacent battery cell; If the insulation resistance between the battery cell to be tested and the adjacent battery cell is less than the standard value, it is determined that the grouping detection result of the battery cell to be tested is abnormal grouping.

2. The method according to claim 1, wherein The determining the battery cell to be tested in the battery pack includes: Obtain the voltage at both ends of each battery cell in the battery pack; If the voltage at both ends of the battery cell is lower than the average voltage of the cells in the module or there is a specified single battery by the user, then take this battery cell as the battery cell to be tested.

3. The method according to claim 1 or 2, characterized in that, The detecting whether the self-discharge of the battery cell to be tested is abnormal to obtain a battery detection result includes: For the test battery pack composed of battery cells in the battery pack except the battery cell to be tested, calculate the self-discharge rate of the test battery pack in multiple time periods; Based on the self-discharge rate of the test battery pack in the multiple time periods, fit to obtain a standard self-discharge curve; For each battery cell to be tested, calculate the self-discharge rate of the battery cell to be tested; Obtain the battery detection result of the battery cell to be tested by comparing the relative position of the self-discharge rate of the battery cell to be tested and the standard self-discharge curve.

4. The method according to claim 3, characterized in that The calculating the self-discharge rate of the test battery pack in multiple time periods for the test battery pack composed of battery cells in the battery pack except the battery cell to be tested includes: For the test battery pack composed of battery cells in the battery pack except the battery cell to be tested, obtain the static voltage of the test battery pack at multiple moments; According to the static voltage of the test battery pack at the multiple moments, obtain the duration of the corresponding time period by taking the difference between adjacent moments; take the difference between the static voltages at the adjacent moments to obtain the change value of the static voltage within the corresponding time period; For each time period, calculate the ratio of the change value of the static voltage in the time period to the duration of the time period to obtain the self-discharge rate of the test battery pack in the multiple time periods.

5. The method according to claim 3, wherein Before calculating the self-discharge rate of each battery cell to be tested, it further includes: For each battery cell to be tested, disconnect the components between the battery cell to be tested and other battery cells; Discharge the battery cell to be tested to the cut-off voltage, charge it to a predetermined power after standing, and set it aside.

6. The method according to claim 3, characterized in that, The obtaining the battery detection result of the battery cell to be tested by comparing the relative position of the self-discharge rate of the battery cell to be tested and the standard self-discharge curve includes: If the position of the self-discharge rate of the battery cell under test in the coordinate system is above the standard self-discharge curve in the coordinate system, it is determined that the battery detection result of the battery cell under test is abnormal self-discharge.

7. A positioning device for abnormal self-discharge of a battery pack, characterized in that, Including: A determination device for determining the battery cell under test in the battery pack; A detection device for detecting whether the grouping of the battery cell under test is abnormal to obtain a grouping detection result; And detecting whether the self-discharge of the battery cell under test is abnormal to obtain a battery detection result; A positioning device for performing self-discharge abnormal fault location of the battery pack according to the grouping detection result and the battery detection result; Specifically, the detection device is used to measure the insulation resistance value between the casings of adjacent battery cells in the battery pack except the battery cell under test as a standard value; Specifically, the detection device is further used to measure the insulation resistance between the battery cell under test and the casing of the adjacent battery cell for each battery cell under test; Specifically, the detection device is further used to determine that the grouping detection result of the battery cell under test is abnormal grouping if the insulation resistance between the battery cell under test and the adjacent battery cell is less than the standard value.

8. The device according to claim 7, wherein Specifically, the determination device is used to obtain the voltage across each battery cell in the battery pack; Specifically, the determination device is further used to use the battery cell as the battery cell under test if the voltage across the battery cell is lower than the average voltage of the cells in the module or there is a user-specified single battery cell.

9. The device according to claim 7 or 8, wherein Specifically, the detection device is further used to calculate the self-discharge rate of the test battery pack composed of battery cells in the battery pack except the battery cell under test for multiple time periods; Specifically, the detection device is further used to fit a standard self-discharge curve based on the self-discharge rate of the test battery pack for the multiple time periods; Specifically, the detection device is further used to calculate the self-discharge rate of each battery cell under test; Specifically, the detection device is further used to obtain the battery detection result of the battery cell under test by comparing the relative position of the self-discharge rate of the battery cell under test with the standard self-discharge curve.

10. The device according to claim 9, wherein Specifically, the detection device is further used to obtain the static voltage of the test battery pack at multiple moments for the test battery pack composed of battery cells in the battery pack except the battery cell under test; Specifically, the detection device is further used to obtain the duration of the corresponding time period by taking the difference between adjacent moments according to the static voltage of the test battery pack at the multiple moments; taking the difference between the static voltages at the adjacent moments to obtain the change value of the static voltage within the corresponding time period; Specifically, the detection device is further used to calculate the ratio of the change value of the static voltage in each time period to the duration of the time period for each time period to obtain the self-discharge rate of the test battery pack for the multiple time periods.

11. The device according to claim 9, wherein The detection device is specifically further configured to disconnect the component formed between the battery cell under test and other battery cells for each battery cell under test; The detection device is specifically further configured to discharge the battery cell under test to the cut-off voltage, charge it to a predetermined power after standing, and then leave it alone.

12. The device according to claim 9, wherein The detection device is specifically further configured to determine that the battery detection result of the battery cell under test is abnormal self-discharge if the position of the self-discharge rate of the battery cell under test in the coordinate system is above the standard self-discharge curve in the coordinate system.

13. An electronic device, characterized in that, including: a processor, and a memory communicatively connected to the processor; The memory stores computer execution instructions; The processor executes the computer execution instructions stored in the memory to implement the method according to any one of claims 1-6.

14. A computer-readable storage medium, characterized in that, Computer execution instructions are stored in the computer-readable storage medium, and when the computer execution instructions are executed by a processor, they are used to implement the method according to any one of claims 1-6.

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