Line detection method and device and electronic equipment

Abstract

The invention provides a line detection method and device and electronic equipment, and relates to the technical field of battery cell protection. The line detection method comprises the steps that at least two times of single-cell voltage data of a battery collected at a target time interval are acquired, detection data of each cell are obtained, the single-cell voltage data collected at a single time comprise the voltage of each cell of the battery, and the detection data comprise the voltages collected at two times of the cell; and for each battery cell, when it is determined that the voltage relative change trend of the battery cell and the adjacent battery cell accords with a first change trend according to the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, forbidding the battery cell, the first change trend is the relative change trend of the voltage of two adjacent cells under the condition that one cell is broken. According to the invention, the reliability of battery disconnection detection in a discontinuous scene in which the battery exists is effectively improved.

Description

Technical Field

[0001] The present application belongs to the technical field of battery cell protection, and specifically relates to a circuit detection method, device and electronic equipment. Background Art

[0002] Battery Management System (BMS) is a key technology in applications such as electric vehicles and energy storage systems. It is responsible for monitoring and managing battery energy storage units to ensure the safety of batteries during charging and discharging.

[0003] The current BMS can be connected to each cell in the battery through a voltage acquisition line to collect the voltage of each cell and obtain the single-cell voltage data of the battery. Then, the single-cell voltage data is used to determine whether the battery is abnormal, so that battery protection measures can be taken in time according to the judgment results. Among them, using single-cell voltage data for BMS disconnection detection to determine whether there is a circuit break in the battery is an important means of protecting the battery.

[0004] Due to bumpy transportation and use, some terminals on the battery of electric equipment may become loose and tight from time to time. For example, the voltage acquisition line of the BMS and the battery terminals may be intermittent due to bumps. This causes the voltage data of a single cell to change instantaneously when a single terminal is loose, which in turn triggers the battery disconnection protection due to the BMS disconnection detection. However, once the current battery disconnection protection is triggered, the battery will become unusable, so the battery must be returned to the factory for repair. During maintenance, the battery terminals may be tightened again, making it impossible for maintenance personnel to perform power-off analysis based on the normal battery cell voltage data. Obviously, the current BMS disconnection detection method has poor reliability when dealing with intermittent battery scenarios. Summary of the invention

[0005] The present application aims to provide a line detection method, device and electronic device, which at least solves the problem that the line break detection method in the related art has poor reliability when dealing with intermittent battery conditions. In order to solve the above technical problems, the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a line detection method, which is applied to a BMS, and the method includes:

[0007] Acquire single-cell voltage data of the battery collected at least twice at a target time interval to obtain detection data of each battery cell, wherein the single-cell voltage data collected once includes the voltage of each battery cell of the battery, and the detection data includes the voltages collected twice for the battery cell;

[0008] For each battery cell, if it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltages of the battery cell and the adjacent battery cells meets the first change trend, the battery cell is disabled, and the first change trend is the relative change trend of the voltages of two adjacent battery cells when one of the battery cells is broken.

[0009] Optionally, the method further includes: for the disabled battery cell, when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells does not conform to the first change trend, enabling the battery cell.

[0010] Optionally, determining, based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, that the relative change trend of the voltage of the battery cell and the adjacent battery cell does not conform to a first change trend includes:

[0011] According to the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, it is determined that the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the second change trend, and the second change trend is the relative change trend of the voltage of two adjacent battery cells when there is no disconnection.

[0012] Optionally, determining, based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, that a relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to a second change trend includes:

[0013] When it is determined that the voltages of the battery cell and the adjacent battery cells meet a recovery condition based on the detection data of the battery cell and the detection data of the adjacent battery cells, it is determined that the relative change trend of the voltages of the battery cell and the adjacent battery cells conforms to a second change trend, wherein the recovery condition includes: the absolute value of the voltage difference between the battery cell and the adjacent battery cell collected at a later time is less than a first difference threshold, and the absolute value of the voltage difference between the battery cell and the adjacent battery cell collected at a later time is less than the absolute value of the voltage difference between the battery cell and the adjacent battery cell collected at a previous time.

[0014] Optionally, the battery cell and the adjacent battery cell are the nth battery cell and the n+1th battery cell respectively; and determining, based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, that a relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to a first change trend includes:

[0015] When it is determined that the voltages of the battery cell and the adjacent battery cell meet a disconnection trigger condition according to the detection data of the battery cell and the detection data of the adjacent battery cell, it is determined that a relative change trend of the voltages of the battery cell and the adjacent battery cell meets a first change trend, wherein the disconnection trigger condition includes:

[0016] The voltage of the n+1th battery cell collected at the last time is greater than the sum of the voltage of the nth battery cell and the first voltage threshold,

[0017] and the target average value of the voltages of the n+1th battery cell and the nth battery cell is greater than or equal to a second voltage threshold,

[0018] and the absolute value of the difference between the target voltage and the target average value is less than or equal to a third voltage threshold, and the target voltage is 0.5 times the sum of the voltages of the n+1th battery cell and the nth battery cell collected the next time,

[0019] and the voltage of the n+1th battery cell collected at the last time is greater than or equal to the sum of the voltage of the n+1th battery cell collected at the last time and the target voltage parameter,

[0020] And the voltage of the nth battery cell collected at a previous time is greater than or equal to the sum of the voltage of the nth battery cell collected at a later time and a target voltage parameter.

[0021] Optionally, the method further comprises:

[0022] Creating a voltage data queue, wherein the voltage data queue includes x storage units, wherein x satisfies: x=p÷q, wherein p is the target duration, and q is the collection interval duration;

[0023] Collect the single-cell voltage data of the battery at intervals of the collection interval;

[0024] In the case where the voltage data queue has an idle storage unit, inserting the collected single-cell voltage data into the voltage data queue; in the case where the voltage data queue does not have an idle storage unit, deleting the single-cell voltage data inserted earliest in the voltage data queue, and inserting the collected single-cell voltage data into the voltage data queue;

[0025] The obtaining of single-cell voltage data of the battery collected at least twice with a target time interval includes: when the voltage data queue does not have an idle storage unit, obtaining the single-cell voltage data inserted earliest and the single-cell voltage data inserted last in the voltage data queue.

[0026] Optionally, disabling the battery cell includes: disabling a battery balancing circuit of the battery cell and the adjacent battery cell, prohibiting the battery cell and the adjacent battery cell from participating in calculating the state of charge SOC of the battery, prohibiting execution of an imbalance fault diagnosis of the battery, and prohibiting execution of an excessive voltage difference protection diagnosis of the battery.

[0027] Optionally, enabling the battery cell includes: starting the battery balancing circuit of the battery cell and the adjacent battery cell, and enabling the battery cell and the adjacent battery cell to participate in calculating the state of charge SOC of the battery, and when all the battery cells of the battery are started, resuming the imbalance fault diagnosis of the battery and the excessive voltage difference protection diagnosis.

[0028] Optionally, the method further comprises: when the battery is initialized, setting a disconnection mark parameter of each cell of the battery as a first parameter;

[0029] For each battery cell, when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cell that the voltage relative change trend of the battery cell and the adjacent battery cell meets the first change trend, disabling the battery cell includes:

[0030] For each battery cell, if the disconnection mark parameter of the battery cell is the first parameter, then when it is determined according to the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the first change trend, the battery cell is disabled and the disconnection mark parameter of the battery cell is updated to the second parameter;

[0031] The disabled battery cell includes: the battery cell whose disconnection mark parameter is the second parameter.

[0032] In a second aspect, an embodiment of the present application provides a circuit detection device, which is applied to a BMS, and the device includes:

[0033] An acquisition module is used to acquire single-cell voltage data of a battery collected at least twice at a target time interval to obtain detection data of each cell, wherein the single-cell voltage data collected once includes the voltage of each cell of the battery, and the detection data includes the voltages collected twice for the cell;

[0034] a determination module, for each battery cell, disabling the battery cell when it is determined, based on the detection data of the battery cell and the detection data of the adjacent battery cell, that the relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to a first change trend, wherein the first change trend is the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected

[0035] In a third aspect, an embodiment of the present application provides an electronic device, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the first aspect are implemented.

[0036] In a fourth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented.

[0037] In a fifth aspect, an embodiment of the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the method described in the first aspect.

[0038] In a sixth aspect, an embodiment of the present application provides a computer program product, which is stored in a storage medium and is executed by at least one processor to implement the method described in the first aspect.

[0039] In the embodiment of the present application, the detection data of each battery cell is obtained by acquiring the single-cell voltage data of the battery collected at least twice at a target time interval, and the detection data of a single battery cell includes the voltage collected twice for the battery cell. Among them, for each battery cell, the technical solution of the present application can be based on the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, so as to determine whether the voltage change trend of the battery cell and the adjacent battery cell within the total time of the at least two acquisitions conforms to the first change trend, so as to disable the battery cell when the relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to the first change trend. Among them, the first change trend is the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected. Compared with the solution of using instantaneous data to trigger the overall disconnection protection of the battery in the related art, the technical solution of the present application can use the overall data within a period of time to determine whether to disable the disconnected battery cell in the battery, so as to perform disconnection protection for a single battery cell, effectively improving the reliability of battery disconnection detection in the intermittent battery scene. Moreover, compared with related technologies, the line break protection for a single battery cell does not need to disable the entire battery, thereby effectively improving the utilization rate of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below.

[0041] Figure 1 is a flow chart of a line detection method provided by an embodiment of the present application;

[0042] Figure 2is a flow chart of another line detection method provided by an embodiment of the present application;

[0043] Figure 3 It is a schematic diagram of the operation of a voltage data queue provided in an embodiment of the present application;

[0044] Figure 4 This is a schematic diagram of voltage change of a battery cell provided in an embodiment of the present application when the battery cell is disconnected;

[0045] Figure 5 is a flow chart of another line detection method provided in an embodiment of the present application;

[0046] Figure 6 This is a schematic diagram of voltage changes of a battery cell under normal conditions provided in an embodiment of the present application;

[0047] Figure 7 is a flow chart of another line detection method provided in an embodiment of the present application;

[0048] Figure 8 This is a block diagram of another line detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0051] Battery Management System (BMS) is a key technology in applications such as electric vehicles and energy storage systems. It is responsible for monitoring and managing battery energy storage units to ensure the safety of batteries during charging and discharging.

[0052] The current BMS can be connected to each cell in the battery through a voltage collection line to collect the voltage of each cell and obtain the single-cell voltage data of the battery.

[0053] Single-cell voltage data is one of the important data sources for BMS to manage batteries. When the voltage acquisition line is broken, the BMS will collect incorrect single-cell voltage data, which will affect the subsequent BMS's judgment on the health and safety of the battery. When a normal battery has a voltage acquisition line break, the voltage of the two adjacent cells at the battery break will show a phenomenon of one cell voltage rising and one cell voltage falling, causing the BMS to trigger undervoltage, overvoltage, excessive voltage difference, disconnection and other battery protection, which will cause the battery to be unable to be used normally. In this way, when repairing the battery, maintenance personnel need to disassemble the battery pack to measure the actual voltage of the battery cell, and then diagnose the disconnection problem of the voltage acquisition line.

[0054] However, for electric equipment such as electric vehicles and electric three-way vehicles, some terminals on the battery may become loose or tight due to bumpy transportation and use. For example, the voltage acquisition line of the BMS and the battery terminals may be intermittent due to bumps. This may cause the voltage data of a single cell to change instantaneously when a single terminal becomes loose, which in turn triggers the battery disconnection protection due to the BMS disconnection detection.

[0055] However, once the current battery disconnection protection is triggered, the battery will become unusable and must be returned to the factory for repair. During maintenance, the battery terminals may be plugged in again, making it impossible for maintenance personnel to perform power-off analysis based on the normal battery cell voltage data. Obviously, the current BMS disconnection detection method has poor reliability when dealing with intermittent battery scenarios, and because the battery has a certain probability of mistakenly entering the disconnection guarantee state, the battery also has a low utilization rate.

[0056] Please refer to Figure 1 , which shows a flow chart of a line detection method provided in an embodiment of the present application. The line detection method can be applied to BMS, which is used to collect the voltage of each battery cell in the battery. Optionally, the line detection method can be executed by a processing device in the BMS. Alternatively, in the case where the line detection method is applied to a vehicle, the line detection method can be executed by the vehicle controller of the vehicle, and the vehicle controller can obtain the single-cell voltage data of the battery through the BMS to execute the method provided in an embodiment of the present application. It should be noted that the following description takes the line detection method executed by the BMS as an example. Figure 1 As shown, the line detection method includes:

[0057] Step 101, obtain single-cell voltage data of the battery collected at least twice at a target time interval to obtain detection data of each cell. The single-cell voltage data collected once includes the voltage of each cell of the battery. The detection data includes the voltage collected twice for the cell.

[0058] Optionally, the BMS can collect the voltage data of a single battery cell once every target time interval to obtain the voltage data of a single battery cell collected at least twice adjacently to obtain the detection data of each battery cell. The detection data of a single battery cell includes the voltage collected twice by the BMS for the battery cell.

[0059] For example, assume that the BMS is used to obtain single-cell voltage data of a battery collected twice at a target time interval to perform subsequent processing. And assume that the target time length can be 10s. The BMS can collect single-cell voltage data of a battery once every 10s, and after each collection of single-cell voltage data of a battery, obtain the single-cell voltage data of the battery collected last time and the single-cell voltage data collected this time to obtain the detection data of each battery cell. The detection data of a single battery cell includes the voltage collected by the BMS twice adjacent to the battery cell.

[0060] In an optional implementation, the BMS is used to obtain single-cell voltage data of the battery collected twice at a target time interval to perform subsequent processing. Based on this, optionally, Figure 2 As shown, the line detection method includes:

[0061] Step 201: Create a voltage data queue. The voltage data queue includes x storage units.

[0062] In the embodiment of the present application, the number x of storage units in the voltage data queue (gVoltQueue) (i.e., the length of the voltage data queue V_QUEUE_SIZE) satisfies: x=p÷q. p is the target duration, and q is the acquisition interval duration. Each storage unit is used to store the voltage data of a single battery collected once.

[0063] The voltage data queue has a front data index (frontIndex) and a rear data index (rearIndex). The front data index is used to indicate the front data in the voltage data queue, that is, the earliest inserted data. The rear data index is used to indicate the rear data in the voltage data queue, that is, the last inserted data. Based on this, Figure 3 As shown, in case A where no data is inserted into the voltage data queue, the head data index and the tail data index both indicate the first storage unit in the voltage data queue.

[0064] For example, if the BMS is used to collect the single-cell voltage data of the battery once every 1 second, and the voltage data queue is used to store the single-cell voltage data for 10 seconds, the voltage data queue may have 10 storage units.

[0065] Step 202: collect voltage data of a single cell of the battery at each collection interval.

[0066] In the embodiment of the present application, the BMS can collect the voltage data of a single battery cell at each collection interval, and determine whether the voltage data queue has an idle storage unit to store the collected voltage data of a single battery cell. Optionally, the collection interval can be 1 second, 0.5 seconds, 1.5 seconds, etc.

[0067] The tail data index can be shifted back one position each time a single cell voltage data is stored, that is, each time a storage unit is occupied, to indicate the next storage unit. For example, please continue to refer to Figure 3 , in case B when data is inserted into the voltage data queue for the first time, the head data index is not. The tail data index is moved back one position to indicate the second storage unit in the voltage data queue. And, in case C when there is only the last storage unit left in the voltage data queue without data inserted, the tail data index indicates the last storage unit. If data is inserted into the last storage unit, the tail data index moves to the first position of the voltage data queue to indicate the first element in the voltage data queue. At this time, the tail data index and the head data index meet, indicating the same element in the voltage data queue.

[0068] Based on this, the BMS can determine whether the voltage data queue has free storage units by determining whether the data index at the end of the queue is consistent with the data index at the head of the queue. Of course, the BMS can also determine whether the voltage data queue has free storage units in other ways. For example, the BMS can determine whether the element length of the data inserted in the voltage data queue is equal to the queue length, so that when the element length is equal to the queue length, it is determined that the voltage data queue does not have free storage units; when the element length is less than the queue length, it is determined that the voltage data queue has free storage units.

[0069] Step 203: When the voltage data queue has an idle storage unit, insert the collected single-cell voltage data into the voltage data queue.

[0070] In the embodiment of the present application, when the voltage data queue has an idle storage unit, the collected single-section voltage data can be directly inserted into the voltage data queue, and the tail data index can be shifted back by one position accordingly.

[0071] Step 204 : When the voltage data queue does not have an idle storage unit, delete the earliest inserted single-cell voltage data in the voltage data queue, and insert the collected single-cell voltage data into the voltage data queue.

[0072] In the embodiment of the present application, when the voltage data queue does not have an idle storage unit, it indicates that the voltage data queue is full. The BMS can delete the earliest inserted single-cell voltage data in the voltage data queue, that is, the BMS can discard the single-cell voltage data indicated by the head data index, and move the head data index back one position. Then, the BMS inserts the collected single-cell voltage data into the voltage data queue, and moves the tail data index back one position accordingly. For a specific example, please continue to refer to Figure 3 , when the voltage data queue is full, the 10 storage units of the voltage data queue are written with 1 to 10 in sequence, and the tail data index and the head data index both point to the first element of the voltage data queue. In case D of writing data 11 to the voltage data queue, the first element of the voltage data queue is deleted, data 11 is written to the first storage unit of the voltage data queue, and the head data index is shifted back by one position to indicate the second element data 2.

[0073] Based on this, the process of step 101 of acquiring the single-cell voltage data of the battery collected at least twice with a target time interval may include: when the voltage data queue does not have an idle storage unit, acquiring the earliest inserted single-cell voltage data in the voltage data queue and the last inserted single-cell voltage data, so as to obtain the single-cell voltage data of the battery collected twice with a target time interval.

[0074] Optionally, when the voltage data queue does not have an idle storage unit, the BMS can read the single-cell voltage data indicated by the head data index and the tail data index to obtain the earliest inserted single-cell voltage data and the last inserted single-cell voltage data in the voltage data queue. Figure 3 In the case D shown, the BMS can read the first element and the second element in the voltage data queue to obtain the single-cell voltage data of the battery collected twice at the target time interval.

[0075] Step 102: for each battery cell, if it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells meets the first change trend, the battery cell is disabled. The first change trend is the relative change trend of the voltage of two adjacent battery cells when one of the battery cells is disconnected.

[0076] In the embodiment of the present application, after obtaining single-cell voltage data collected at least twice with a target time interval, the BMS can perform disconnection detection on each battery cell in turn to determine whether to disable the battery cell. The disconnection detection for each battery cell includes: judging whether the relative change trend of the voltage of the battery cell and the adjacent battery cell within the total time of the at least two collections conforms to the first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cell.

[0077] In the case where the relative change trend of the voltage of the battery cell and the adjacent battery cell within the total acquisition time of at least two times conforms to the first change trend, it indicates that the battery cell is continuously in a disconnected state within the total acquisition time of at least two times. The BMS can disable the battery cell so that the battery can operate normally using other battery cells. Correspondingly, optionally, in the case where the relative change trend of the voltage of the battery cell and the adjacent battery cell within the total acquisition time of at least two times does not conform to the first change trend, it indicates that the battery cell is not continuously in a disconnected state within the total acquisition time of at least two times, and there is no disconnection fault in the battery cell. The BMS can continue to enable the battery cell to operate normally.

[0078] Among them, the adjacent cell of a single cell may refer to one of the two cells directly connected in series with the cell. Optionally, the adjacent cell of the cell may be a downstream cell of the two cells directly connected in series with the cell, and the downstream cell receives the output signal of the cell. That is, the adjacent cell may be a cell for receiving the output signal of the cell of the two cells directly connected in series with the cell. For example, it is assumed that cells A, B and C in the battery are connected in series in sequence. The adjacent cell of battery B may refer to cell C.

[0079] In the embodiment of the present application, the first change trend is the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected. Optionally, the electronic device can pre-simulate the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected, so as to judge whether the battery is disconnected. Among them, resistors of different resistance values ​​can be connected in series on different voltage collection lines on the battery pack (i.e., battery) to simulate different degrees of disconnection. Furthermore, the single-cell voltage data of the battery under different degrees of disconnection is collected by the BMS, and the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected is obtained.

[0080] For example, Figure 4 As shown, it shows a schematic diagram of voltage changes of a battery cell and its adjacent battery cells when a voltage collection line of a battery cell is broken. Figure 4 For a battery with 13 cells, when the voltage collection line of the 6th cell is broken, if the battery is discharged normally, the voltage change curve of the 6th cell B6 and the voltage change curve of the 7th cell B7 are shown. Figure 4The horizontal axis of the voltage change curve is time, in seconds (s); the vertical axis is voltage, in millivolts (mV). Figure 4 It can be seen that the output voltage of the 6th cell B6 dropped by 40mV within 20 seconds after the voltage collection line of the 6th cell was disconnected, and dropped by 67mV between 20 seconds and 30 seconds. Correspondingly, the output voltage of the 7th cell B7 rose by 55mV within 20 seconds after the voltage collection line of the 6th cell was disconnected, and rose by 38mV between 20 seconds and 30 seconds. 30 seconds after the voltage collection line of the 6th cell was disconnected, the voltage difference between the 6th cell B6 and the 7th cell B7 reached 200mV.

[0081] It is not difficult to see that the voltage of the 6th battery cell B6 decreases 10 seconds after the voltage collection line of the 6th battery cell is broken, and the voltage of the 7th battery cell B7 increases 10 seconds after the voltage collection line of the 6th battery cell is broken. The voltage difference between the 6th battery cell B6 and the 7th battery cell B7 gradually increases 10 seconds after the voltage collection line of the 6th battery cell is broken, and the voltage change curve of the 6th battery cell B6 and the voltage change curve of the 7th battery cell B7 have certain symmetry characteristics.

[0082] Since 10 seconds after the voltage collection line of the 6th battery cell was disconnected, the voltage of the 6th battery cell B6 and the 7th battery cell B7 changed significantly. Therefore, it shows that the battery cell voltage data with an interval of at least 10 seconds can reflect whether the battery cell is disconnected. Therefore, the target time length can be 10 seconds, and the BMS can use the single-cell voltage data before and after 10 seconds to determine whether there is a disconnected battery cell in the battery. Of course, the target time length can also be greater than 10 seconds. For example, the target time length can be 11 seconds or 12 seconds, etc.

[0083] Based on this, in some embodiments, the BMS can store the first voltage change curves of two adjacent battery cells when one of the battery cells is disconnected. The BMS can draw the voltage change curve of each battery cell after acquiring the single-cell voltage data of the battery collected at least twice at a target time interval and obtaining the detection data of each battery cell. For each battery cell, the BMS calculates the curve similarity between the voltage change curve of the battery cell and the voltage change curve of the adjacent battery cell of the battery cell and the first voltage change curve to obtain a similarity value.

[0084] When the similarity value is greater than the similarity threshold, indicating that the voltage change curve of the battery cell and its adjacent battery cell is highly similar to the first voltage change curve, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cell conforms to the first change trend, and the battery cell is disabled. Correspondingly, optionally, when the similarity value is less than the similarity threshold, indicating that the voltage change curve of the battery cell and its adjacent battery cell is less similar to the first voltage change curve, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cell does not conform to the first change trend, and the battery cell is enabled.

[0085] It should be noted that the richer the single-cell voltage data acquired by the BMS, the richer the voltage data of the single battery cell, and thus the more accurate the voltage change curve of the single battery cell drawn. Furthermore, based on the drawn voltage change curve, the more accurate the judgment result of whether the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the first change trend is, the higher the accuracy of the battery cell disconnection detection and the higher the reliability.

[0086] For example, the BMS can obtain the single-cell voltage data of the battery collected 10 times at target time intervals, and draw the voltage change curve of each cell. For each cell, the BMS calculates the curve similarity between the voltage change curve of the cell and the voltage change curve of the adjacent cell of the cell and the first voltage change curve to obtain a similarity value. Then, based on the relationship between the similarity data and the similarity threshold, determine whether the relative change trend of the voltage of the cell and the adjacent cell conforms to the first change trend, so as to determine whether to disable the cell or continue to enable the cell.

[0087] In other embodiments, the battery cell and the adjacent battery cell are the nth battery cell and the n+1th battery cell, respectively. The process in which the BMS determines that the relative change trend of the voltage of the battery cell and the adjacent battery cell within the target time length conforms to the first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell may include: determining that the relative change trend of the voltage of the battery cell and the adjacent battery cell within the target time length conforms to the first change trend when it is determined that the voltage of the battery cell and the adjacent battery cell meets the disconnection trigger condition based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell. Among them, the disconnection trigger condition includes:

[0088] The voltage of the n+1th battery cell collected the next time is greater than the sum of the voltage of the nth battery cell and the first voltage threshold, and the target average voltage of the n+1th battery cell and the nth battery cell is greater than or equal to the second voltage threshold, and the absolute value of the difference between the target voltage and the target average voltage is less than or equal to the third voltage threshold, and the voltage of the n+1th battery cell collected the next time is greater than or equal to the sum of the voltage of the n+1th battery cell collected the previous time and the target voltage parameter, and the voltage of the nth battery cell collected the previous time is greater than or equal to the sum of the voltage of the nth battery cell collected the next time and the target voltage parameter. The target voltage is 0.5 times the sum of the voltage of the n+1th battery cell and the nth battery cell collected the next time.

[0089] That is, the disconnection trigger conditions include: V(n+1)≧V(n)+VoltDifDisconnect, and Vavg≧VoltAVGDisconnect, and abs((V(n+1)+V(n)) / 2-Vavg)≦ABS_Volt_DifAVG, and V(n+1)≧(V(n+1)_last10s+Volt_10s_Change, and V(n)_last10s≧V(n)+Volt_10s_Change. That is, when the BMS determines that the four conditions included in the disconnection trigger conditions are met based on the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, it determines that the relative change trend of the voltage of the battery cell and the adjacent battery cell within the target time length meets the first change trend, and disables the battery cell.

[0090] Wherein, V(n+1) represents the voltage of the n+1th battery cell collected at the last time. V(n) represents the voltage of the nth battery cell. VoltDifDisconnect represents the first voltage threshold. Vavg represents the target average value of the voltages of the n+1th battery cell and the nth battery cell. VoltAVGDisconnect represents the second voltage threshold. abs() represents the absolute value of the difference. abs((V(n+1)+V(n)) / 2-Vavg) represents the absolute value of the difference between the target voltage and the target average value. ABS_Volt_DifAVG represents the third voltage threshold. V(n+1)_last10s represents the voltage of the n+1th battery cell collected at the last time. Volt_10s_Change represents the target voltage parameter. V(n)_last10s represents the voltage of the nth battery cell collected at the last time.

[0091] In the embodiment of the present application, the detection data of each battery cell is obtained by acquiring the single-cell voltage data of the battery collected at least twice at a target time interval, and the detection data of a single battery cell includes the voltage collected twice for the battery cell. Among them, for each battery cell, the technical solution of the present application can be based on the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, so as to determine whether the voltage change trend of the battery cell and the adjacent battery cell within the total time of the at least two acquisitions conforms to the first change trend, so as to disable the battery cell when the relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to the first change trend. Among them, the first change trend is the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected. Compared with the solution of using instantaneous data to trigger the overall disconnection protection of the battery in the related art, the technical solution of the present application can use the overall data within a period of time to determine whether to disable the disconnected battery cell in the battery, so as to perform disconnection protection for a single battery cell, effectively improving the reliability of battery disconnection detection in the intermittent battery scene. Moreover, compared with related technologies, the line break protection for a single battery cell does not need to disable the entire battery, thereby effectively improving the utilization rate of the battery.

[0092] Please refer to Figure 5 , which shows a flow chart of a line detection method provided in an embodiment of the present application. The line detection method can be applied to BMS, which is used to collect the voltage of each battery cell in the battery. Optionally, the line detection method can be executed by a processing device in the BMS. Alternatively, in the case where the line detection method is applied to a vehicle, the line detection method can be executed by the vehicle controller of the vehicle, and the vehicle controller can obtain the single-cell voltage data of the battery through the BMS to execute the method provided in an embodiment of the present application. It should be noted that the following description takes the line detection method executed by the BMS as an example. Figure 5 As shown, the line detection method includes:

[0093] Step 501, obtain single-cell voltage data of the battery collected at least twice at a target time interval, and obtain detection data of each cell. The single-cell voltage data collected once includes the voltage of each cell of the battery. The detection data includes the voltage collected twice for the cell.

[0094] The explanation and implementation of this step can refer to the aforementioned step 101, and this embodiment of the present application will not be elaborated on this.

[0095] It should be noted that in some embodiments, after obtaining single-cell voltage data collected at least twice at a target time interval, the BMS can sequentially determine whether multiple cells included in the battery are disabled cells. For non-disabled cells, the BMS executes step 502 for the cells; for disabled cells, the BMS executes step 503 for the cells.

[0096] Optionally, the line detection method further includes: when the battery is initialized, setting the disconnection mark parameter of each battery cell of the battery to a first parameter. The first parameter indicates that the battery cell is in an enabled state, that is, the battery is not disabled. After acquiring single-cell voltage data collected at least twice with a target time interval, the BMS can sequentially determine whether the disconnection mark parameter of each battery cell of the battery is the first parameter, so as to determine that the battery cell is a non-disabled battery cell when the disconnection mark parameter is the first parameter; and determine that the battery cell is a disabled battery cell when the disconnection mark parameter is the second parameter. By way of example, the first parameter can be 0; the second parameter can be 1.

[0097] Step 502: For the battery cells that are not disabled, if it is determined based on the detection data of the battery cell and the detection data of the battery cells' adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells meets the first change trend, the battery cell is disabled.

[0098] In some embodiments of the present application, for each battery cell, if the disconnection mark parameter of the battery cell is the first parameter, then when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells within the target time length meets the first change trend, the battery cell is disabled and the disconnection mark parameter of the battery cell is updated to the second parameter. The explanation and implementation of this step can refer to the aforementioned step 102, and the embodiments of the present application will not be repeated here.

[0099] Step 503: for the disabled battery cell, when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells within the target time does not conform to the first change trend, the battery cell is enabled.

[0100] In some embodiments of the present application, for each battery cell, if the disconnection mark parameter of the battery cell is the second parameter, then when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells within the target time length does not conform to the first change trend, the battery cell is enabled and the disconnection mark parameter of the battery cell is updated to the first parameter.

[0101] In some embodiments, as described above, the BMS may store the first voltage change curves of two adjacent battery cells when one of the battery cells is disconnected. The BMS may draw the voltage change curve of each battery cell after acquiring the single-cell voltage data of the battery collected at least twice at a target time interval and obtaining the detection data of each battery cell. For each disabled battery cell, the BMS calculates the curve similarity between the voltage change curve of the battery cell and the voltage change curve of the adjacent battery cell of the battery cell and the first voltage change curve to obtain a similarity value.

[0102] When the similarity value is less than the similarity threshold, indicating that the voltage change curves of the battery cell and its adjacent battery cell are less similar to the first voltage change curve, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cell does not conform to the first change trend, and the battery cell is enabled.

[0103] In other embodiments, the process in which the BMS determines, based on the detection data of the battery cell and the detection data of the adjacent battery cell, that the relative change trend of the voltage of the battery cell and the adjacent battery cell within the target time does not conform to the first change trend may include:

[0104] According to the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, it is determined that the relative change trend of the voltage of the battery cell and the adjacent battery cells within the target time length conforms to the second change trend. The second change trend is the relative change trend of the voltage of two adjacent battery cells when neither of them is disconnected.

[0105] Optionally, the electronic device can simulate in advance the relative change trend of the voltage of two adjacent cells when there is no disconnection, so as to judge whether the battery is activated. The single cell voltage data of the battery when it is not disconnected is collected by the BMS to obtain the relative change trend of the voltage of two adjacent cells when there is no disconnection.

[0106] For example, with Figure 4 In contrast, if Figure 6 As shown, it shows a schematic diagram of voltage changes of two adjacent battery cells when the voltage collection line of a battery is not broken.

[0107] Figure 6 For a battery with 13 cells, when the voltage collection line of the 6th cell and the voltage collection line of the 7th cell are not broken, if the battery is discharged normally, then the voltage change curve of the 6th cell B6 and the voltage change curve of the 7th cell B7 are shown. Figure 6 The horizontal axis of the voltage change curve is time, in seconds; the vertical axis is voltage, in millivolts. Figure 6 It can be seen that the output voltage of the 6th battery cell B6 increased by 371mV within 2 seconds after the voltage collection line of the 6th battery cell was closed from disconnection, and increased by 371mV within 10 seconds after closing. Correspondingly, the output voltage of the 7th battery cell B7 decreased by 373mV within 2 seconds after the voltage collection line of the 6th battery cell was closed from disconnection, and decreased by 374mV within 10 seconds after closing. The voltage difference between the 6th battery cell B6 and the 7th battery cell B7 was 6mV 2 seconds after the voltage collection line of the 6th battery cell was closed, and was 5mV 10 seconds after closing.

[0108] It is not difficult to see that the voltage difference between the 6th cell B6 and the 7th cell B7 decreases 10 seconds after the voltage collection line of the 6th cell is closed from disconnection. The voltage difference between the 6th cell B6 and the 7th cell B7 10 seconds after the voltage collection line of the 6th cell is closed is greater than the voltage difference between the 6th cell B6 and the 7th cell B7 in the first 10 seconds after the voltage collection line of the 6th cell is closed.

[0109] Based on this, in some embodiments, the BMS can store the second voltage change curve of two adjacent battery cells when neither cell is disconnected. The BMS can draw the voltage change curve of each disabled battery cell after acquiring the single-cell voltage data of the battery collected at least twice at a target time interval and obtaining the detection data of each battery cell. For each disabled battery cell, the BMS calculates the curve similarity between the voltage change curve of the battery cell and the voltage change curve of the adjacent battery cell of the battery cell and the second voltage change curve to obtain a similarity value.

[0110] When the similarity value is greater than the similarity threshold, indicating that the voltage change curve of the battery cell and its adjacent battery cell is highly similar to the second voltage change curve, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cell conforms to the second change trend, and the battery cell is enabled.

[0111] It should be noted that the richer the single-cell voltage data obtained by the BMS, the richer the voltage data of the single battery cell, and thus the more accurate the voltage change curve of the single battery cell drawn. Furthermore, based on the drawn voltage change curve, the more accurate the judgment result of whether the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the second change trend is, the higher the accuracy of the battery cell disconnection detection and the higher the reliability.

[0112] For example, the BMS can obtain single-cell voltage data of the battery collected 10 times at target time intervals, and draw a voltage change curve for each cell. For each disabled cell, the BMS calculates the curve similarity between the voltage change curve of the cell and the voltage change curve of the adjacent cell of the cell and the second voltage change curve to obtain a similarity value. Furthermore, based on the relationship between the similarity data and the similarity threshold, determine whether the relative voltage change trend of the cell and the adjacent cell conforms to the second change trend to determine whether to enable the cell.

[0113] In other embodiments, the process in which the BMS determines that the relative change trend of the voltage of the battery cell and the adjacent battery cell within the target time length conforms to the second change trend based on the detection data of the battery cell and the detection data of the adjacent battery cell may also include:

[0114] When it is determined that the voltages of the battery cell and its adjacent battery cell meet the recovery condition based on the detection data of the battery cell and the detection data of its adjacent battery cell, it is determined that the relative change trend of the voltages of the battery cell and its adjacent battery cell within the target duration conforms to the second change trend.

[0115] Among them, the recovery condition includes: the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected in the latter time is less than the first difference threshold, and the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected in the latter time is less than the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected in the previous time.

[0116] That is to say, the battery cell and its adjacent battery cell are the nth battery cell and the (n + 1)th battery cell respectively. The recovery condition includes: abs((V(n + 1)-V(n)) < ABS_Volt_Dif_Rls, and abs((V(n + 1)-V(n)) < abs((V(n + 1)_last10s-V(n)_last10s)). Among them, abs((V(n + 1)-V(n)) represents the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected in the latter time. ABS_Volt_Dif_Rls represents the first difference threshold. abs((V(n + 1)_last10s-V(n)_last10s)) represents the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected in the previous time.

[0117] In the embodiments of the present application, after a certain battery cell of the battery is disabled, it is also possible to restart the battery cell when the battery cell resumes without disconnection by setting rules (for example, meeting the recovery condition). This solution further improves the reliability and accuracy of battery disconnection detection in the intermittent scenarios where the battery exists.

[0118] In some embodiments of the present application, the process of the BMS disabling the battery cell may include: disabling the battery equalization circuits of the battery cell and its adjacent battery cell, and prohibiting the battery cell and its adjacent battery cell from participating in the calculation of the state of charge (SOC) of the battery, and prohibiting the execution of the imbalance fault diagnosis of the battery, and prohibiting the execution of the overvoltage difference protection diagnosis of the battery.

[0119] Optionally, when the line detection method is applied to a vehicle, the unified diagnostic service (UDS) of the vehicle has a DTC status bit. Each bit in the DTC status bit represents a fault diagnosis condition of the vehicle. Among them, bit6 of the DTC status bit is an imbalance fault diagnosis flag bit, and the value of bit6 indicates whether the imbalance fault diagnosis is completed. If the value of bit6 is 0, it means that the imbalance fault diagnosis is completed. If the value of bit6 is 1, it means that the imbalance fault diagnosis is not completed. Bit10 of the DTC status bit is an excessive pressure difference protection diagnosis flag bit, and the value of bit10 indicates whether the excessive pressure difference protection diagnosis is completed. If the value of bit10 is 0, it means that the excessive pressure difference protection diagnosis is completed. If the value of bit10 is 1, it means that the excessive pressure difference protection diagnosis is not completed. Based on this, the process of BMS disabling the battery cell may include: BMS disabling the battery balancing circuit of the battery cell and the adjacent battery cell, and prohibiting the battery cell and the adjacent battery cell from participating in the calculation of the battery SOC, and prohibiting the execution of battery imbalance fault diagnosis, and updating bit6 of the DTC status bit to 0, and prohibiting the execution of the battery voltage difference protection diagnosis, and updating bit10 of the DTC status bit to 0.

[0120] In this way, by disabling the battery balancing circuit of the battery cell and the adjacent battery cell, the abnormal voltage of the battery cell after the line is disconnected can be collected to avoid affecting the battery balancing function of the BMS. Similarly, by disabling the participation of the battery cell and the adjacent battery cell in calculating the battery's state of charge, the abnormal voltage of the battery cell after the line is disconnected can be collected to avoid affecting the calculation of the battery's SOC. Similarly, by prohibiting the execution of the battery imbalance fault diagnosis and prohibiting the execution of the battery's excessive voltage difference protection diagnosis, the diagnostic errors of the battery imbalance fault diagnosis caused by the abnormal voltage of the battery cell after the line is disconnected and the diagnostic errors of the excessive voltage difference protection diagnosis can be avoided.

[0121] Correspondingly, optionally, the process of enabling the BMS battery cell may include: starting the battery balancing circuit of the battery cell and the adjacent battery cells, and enabling the battery cell and the adjacent battery cells to participate in calculating the SOC of the battery, and when all the battery cells are started, resuming the battery imbalance fault diagnosis and excessive voltage difference protection diagnosis.

[0122] In order to facilitate understanding of the technical solution of the present application, the line detection method provided by the embodiment of the present application is further described by the following example. For example, the adjacent cell is the downstream cell of the cell. That is, if the cell is the nth cell, the adjacent cell is the n+1th cell. Figure 7 As shown, the line detection method includes:

[0123] Create a two-dimensional circular array queue (i.e., voltage data queue, gVoltQueue). The voltage data queue is used to store the single-cell voltage data of the battery within 10 seconds. The voltage data queue has a front data index (frontIndex), which indicates the single-cell voltage data 10 seconds ago. The rear data index (rearIndex) is used to indicate the storage unit to store the latest collected single-cell voltage data. The front data index and the rear data index are both 0.

[0124] The BMS collects the voltage data of a single battery cell every 1 second.

[0125] Whether the voltage data queue is full is detected based on whether the tail data index and the head data index indicate the same element. If the tail data index and the head data index indicate the same element, it is detected that the voltage data queue is full, and the earliest inserted (i.e., oldest) single-section voltage data in the voltage data queue can be discarded, and the head data index is moved back by one position, and the single-section voltage data is inserted into the storage unit indicated by the tail data index in the voltage data queue, and the tail data index is moved back by one position, and the queue data valid flag (gVQueueDataValid) is set to 1. It can also be understood that the tail data index is moved back by one position every 1 second. Among them, if the tail data index does not indicate the last bit in the voltage data queue, moving the tail data index back by one position means: adding 1 to the tail data index; if the tail data index indicates the last bit in the voltage data queue, moving the tail data index back by one position means: moving the tail data index to the first position in the voltage data queue, that is, setting the tail data index to 0.

[0126] If the tail data index and the head data index do not indicate the same element, the voltage data queue is not full, and the queue data valid flag can be kept at 0, and the single-section voltage data is inserted into the storage unit indicated by the tail data index in the voltage data queue, and the tail data index is moved one position. Among them, similar to the tail data index, if the head data index does not indicate the last position in the voltage data queue, moving the head data index one position means: adding 1 to the head data index. If the head data index indicates the last position in the voltage data queue, moving the head data index one position means: moving the head data index to the first position in the voltage data queue, that is, setting the head data index to 1.

[0127] Determine whether the queue data valid flag is 1.

[0128] When the queue data valid flag is 1, obtain the single cell voltage data indicated by the head data index in the voltage data queue and the latest inserted single cell voltage data to trigger and restore the disconnection detection. Set n=1, 0<n≤m, and n is a positive integer, and m is the total number of cells included in the battery.

[0129] The triggering and recovery of open - circuit detection for the nth battery cell specifically include: judging whether the open - circuit flag parameter of the nth battery cell is 0.

[0130] When the open - circuit flag parameter of the nth battery cell is 0, based on the voltage V(n + 1)_last10s of the nth battery cell in the single - cell voltage data indicated by the head - of - queue data index, the voltage V(n)_last10s of the nth battery cell, the voltage V(n + 1) of the nth battery cell in the single - cell voltage data newly inserted into the voltage data queue, and the voltage V(n) of the nth battery cell, judge whether the open - circuit triggering condition is satisfied. The open - circuit triggering condition includes: V(n + 1)≧V(n)+VoltDifDisconnect, and Vavg≧VoltAVGDisconnect, and abs((V(n + 1)+V(n)) / 2 - Vavg)≦ABS_Volt_DifAVG, and V(n + 1)≧(V(n + 1)_last10s+Volt_10s_Change, and V(n)_last10s≧V(n)+Volt_10s_Change. If the open - circuit triggering condition is satisfied, set the open - circuit flag parameter of the nth battery cell to 1, execute n + 1 (i.e., n++), and judge whether n is equal to m, so as to trigger and recover the open - circuit detection for the (n + 1)th battery cell when n is less than m. If the open - circuit triggering condition is not satisfied, also execute n + 1 (i.e., n++), and judge whether n is equal to m, so as to trigger and recover the open - circuit detection for the (n + 1)th battery cell when n is less than m.

[0131] When the open - circuit flag parameter of the nth battery cell is not 1, that is, the open - circuit flag parameter of the nth battery cell is 0, based on the voltage V(n + 1)_last10s of the nth battery cell in the single - cell voltage data indicated by the head - of - queue data index, the voltage V(n)_last10s of the nth battery cell, the voltage V(n + 1) of the nth battery cell in the single - cell voltage data newly inserted into the voltage data queue, and the voltage V(n) of the nth battery cell, judge whether the recovery condition is satisfied. The recovery condition includes: abs((V(n + 1)-V(n))<ABS_Volt_Dif_Rls, and abs((V(n + 1)-V(n))<abs((V(n + 1)_last10s - V(n)_last10s)). If the recovery condition is satisfied, set the open - circuit flag parameter of the nth battery cell to 0, execute n + 1 (i.e., n++), and judge whether n is equal to m, so as to trigger and recover the open - circuit detection for the (n + 1)th battery cell when n is less than m. If the recovery condition is not satisfied, also execute n + 1 (i.e., n++), and judge whether n is equal to m, so as to trigger and recover the open - circuit detection for the (n + 1)th battery cell when n is less than m.

[0132] When the queue data valid flag is not 1, that is, the queue data valid flag is 0, and when n=m, if the disconnection flag parameters of the m cells of the battery change from 0 to 1, the disconnection fault flag bit is set to 1, and for the cell with the disconnection fault flag parameter of 1, the battery balancing circuit of the cell and the adjacent cell is disabled, and the cell and the adjacent cell are prohibited from participating in the calculation of the battery SOC, and the battery imbalance fault diagnosis is prohibited, and the bit6 of the DTC status bit is updated to 0, and the battery voltage difference excessive protection diagnosis is prohibited, and the bit10 of the DTC status bit is updated to 0.

[0133] If the disconnection flag parameter of the m cells of the battery changes from 1 to 0, the disconnection fault flag is set to 0. For the chip whose disconnection fault flag parameter is 0, the battery balancing circuit of the start-up cell and the adjacent cell is executed, and the cell and the adjacent cell are enabled to participate in calculating the SOC of the battery. When all the cells of the battery are started, the battery imbalance fault diagnosis and excessive voltage difference protection diagnosis are restored.

[0134] In the embodiment of the present application, the detection data of each battery cell is obtained by acquiring the single-cell voltage data of the battery collected at least twice at a target time interval, and the detection data of a single battery cell includes the voltage collected twice for the battery cell. Among them, for each battery cell, the technical solution of the present application can be based on the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, so as to determine whether the voltage change trend of the battery cell and the adjacent battery cell within the total time of the at least two acquisitions conforms to the first change trend, so as to disable the battery cell when the relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to the first change trend. Among them, the first change trend is the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected. Compared with the solution of using instantaneous data to trigger the overall disconnection protection of the battery in the related art, the technical solution of the present application can use the overall data within a period of time to determine whether to disable the disconnected battery cell in the battery, so as to perform disconnection protection for a single battery cell, effectively improving the reliability of battery disconnection detection in the intermittent battery scene. Moreover, compared with related technologies, the line break protection for a single battery cell does not need to disable the entire battery, thereby effectively improving the utilization rate of the battery.

[0135] Please refer to Figure 8 , which shows a block diagram of a line detection device provided in an embodiment of the present application. The line detection device can be applied to BMS. Figure 8 As shown, the line detection device 800 includes: an acquisition module 801 and a determination module 802

[0136] The acquisition module 801 is used to acquire single-cell voltage data of the battery collected at least twice at a target time interval to obtain detection data of each cell, where the single-cell voltage data collected once includes the voltage of each cell of the battery, and the detection data includes the voltages collected twice for the cell;

[0137] The determination module 802 is used to disable the battery cell for each battery cell when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells meets the first change trend, wherein the first change trend is the relative change trend of the voltage of two adjacent battery cells when one of the battery cells is broken.

[0138] Optionally, the determination module 802 is further used to enable a disabled battery cell when it is determined, based on detection data of the battery cell and detection data of adjacent battery cells, that a relative voltage change trend between the battery cell and the adjacent battery cells does not conform to a first change trend.

[0139] Optionally, the determination module 802 is also used to determine, based on the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, whether the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the second change trend, and the second change trend is the relative change trend of the voltage of two adjacent battery cells when there is no disconnection.

[0140] Optionally, the determination module 802 is further configured to determine that a relative change trend of the voltage of the battery cell and the adjacent battery cell meets a second change trend when it is determined that the voltage of the battery cell and the adjacent battery cell meet a recovery condition based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell.

[0141] Among them, the recovery conditions include: the absolute value of the voltage difference between the battery cell collected last time and the adjacent battery cell is less than the first difference threshold, and the absolute value of the voltage difference between the battery cell collected last time and the adjacent battery cell is less than the absolute value of the voltage difference between the battery cell collected last time and the adjacent battery cell.

[0142] Optionally, the battery cell and the adjacent battery cell are the nth battery cell and the n+1th battery cell respectively; the determination module 802 is further used to determine that the relative change trend of the voltage of the battery cell and the adjacent battery cell meets the first change trend when it is determined that the voltage of the battery cell and the adjacent battery cell meets the disconnection trigger condition according to the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, wherein the disconnection trigger condition includes:

[0143] The voltage of the n+1th battery cell collected last time is greater than the sum of the voltage of the nth battery cell and the first voltage threshold, and the target average value of the voltages of the n+1th battery cell and the nth battery cell is greater than or equal to the second voltage threshold, and the absolute value of the difference between the target voltage and the target average value is less than or equal to the third voltage threshold, the target voltage is 0.5 times the sum of the voltages of the n+1th battery cell and the nth battery cell collected last time, and the voltage of the n+1th battery cell collected last time is greater than or equal to the sum of the voltage of the n+1th battery cell collected last time and the target voltage parameter, and the voltage of the nth battery cell collected last time is greater than or equal to the sum of the voltage of the nth battery cell collected last time and the target voltage parameter.

[0144] Optionally, the line detection device 800 further includes:

[0145] A creation module is used to create a voltage data queue, where the voltage data queue includes x storage units, where x satisfies: x = p ÷ q, where p is the target duration and q is the collection interval duration;

[0146] A collection module is used to collect the voltage data of a single battery cell at each collection interval;

[0147] A writing module, used for inserting the collected single-section voltage data into the voltage data queue when the voltage data queue has an idle storage unit, and for deleting the earliest inserted single-section voltage data in the voltage data queue and inserting the collected single-section voltage data into the voltage data queue when the voltage data queue does not have an idle storage unit;

[0148] The acquisition module 801 is further configured to acquire the earliest inserted single-cell voltage data and the latest inserted single-cell voltage data in the voltage data queue when the voltage data queue has no idle storage unit.

[0149] Optionally, the determination module 802 is further used to disable the battery balancing circuit of the battery cell and the adjacent battery cell, and prohibit the battery cell and the adjacent battery cell from participating in the calculation of the SOC of the battery, and prohibit the execution of the battery imbalance fault diagnosis, and prohibit the execution of the battery excessive voltage difference protection diagnosis.

[0150] Optionally, the determination module 802 is further used to start the battery balancing circuit of the battery cell and the adjacent battery cell, and enable the battery cell and the adjacent battery cell to participate in calculating the SOC of the battery, and when all the battery cells of the battery are started, resume executing the battery imbalance fault diagnosis and excessive voltage difference protection diagnosis.

[0151] Optionally, the line detection device 800 further includes: a setting module, configured to set the disconnection mark parameter of each cell of the battery as the first parameter when the battery is initialized;

[0152] The determination module 802 is further configured to, for each battery cell, if the disconnection mark parameter of the battery cell is the first parameter, then, when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the voltage relative change trend of the battery cell and the adjacent battery cells meets the first change trend, disable the battery cell and update the disconnection mark parameter of the battery cell to the second parameter;

[0153] The determination module 802 is further used for determining the battery cell whose disconnection mark parameter is the second parameter.

[0154] In the embodiment of the present application, the detection data of each battery cell is obtained by acquiring the single-cell voltage data of the battery collected at least twice at a target time interval, and the detection data of a single battery cell includes the voltage collected twice for the battery cell. Among them, for each battery cell, the technical solution of the present application can be based on the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, so as to determine whether the voltage change trend of the battery cell and the adjacent battery cell within the total time of the at least two acquisitions conforms to the first change trend, so as to disable the battery cell when the relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to the first change trend. Among them, the first change trend is the relative change trend of the voltage of two adjacent battery cells when one battery cell is disconnected. Compared with the solution of using instantaneous data to trigger the overall disconnection protection of the battery in the related art, the technical solution of the present application can use the overall data within a period of time to determine whether to disable the disconnected battery cell in the battery, so as to perform disconnection protection for a single battery cell, effectively improving the reliability of battery disconnection detection in the intermittent battery scene. Moreover, compared with related technologies, the line break protection for a single battery cell does not need to disable the entire battery, thereby effectively improving the utilization rate of the battery.

[0155] Optionally, the electronic device provided in the embodiment of the present application includes: a processor and a memory, the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the various steps of the above-mentioned line detection method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0156] The embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned line detection method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it is not repeated here. Among them, the processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory, a random access memory, a disk or an optical disk.

[0157] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned line detection method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0158] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0159] An embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement the various processes of the above-mentioned line detection method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0160] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0161] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A line detection method, characterized in that: Applied to a battery management system BMS, the method comprises: Acquire single-cell voltage data of the battery collected at least twice at a target time interval to obtain detection data of each battery cell, wherein the single-cell voltage data collected once includes the voltage of each battery cell of the battery, and the detection data includes the voltages collected twice for the battery cell; For each battery cell, if it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltages of the battery cell and the adjacent battery cells meets the first change trend, the battery cell is disabled, and the first change trend is the relative change trend of the voltages of two adjacent battery cells when one of the battery cells is broken.

2. The method according to claim 1, characterized in that The method further comprises: For the disabled battery cell, when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cell that the relative change trend of the voltage of the battery cell and the adjacent battery cell does not conform to the first change trend, the battery cell is enabled.

3. The method according to claim 2, characterized in that The determining, based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, that the relative change trend of the voltage of the battery cell and the adjacent battery cell does not conform to the first change trend includes: According to the detection data of the battery cell and the detection data of the adjacent battery cells of the battery cell, it is determined that the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the second change trend, and the second change trend is the relative change trend of the voltage of two adjacent battery cells when there is no disconnection.

4. The method according to claim 3, characterized in that Determining, based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, that a relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to a second change trend includes: When it is determined that the voltages of the battery cell and the adjacent battery cell meet a recovery condition based on the detection data of the battery cell and the detection data of the adjacent battery cell, it is determined that a relative change trend of the voltages of the battery cell and the adjacent battery cell meets a second change trend, Among them, the recovery condition includes: the absolute value of the voltage difference between the battery cell and the adjacent battery cell collected at a later time is less than the first difference threshold, and the absolute value of the voltage difference between the battery cell and the adjacent battery cell collected at a later time is less than the absolute value of the voltage difference between the battery cell and the adjacent battery cell collected at a previous time.

5. The method according to claim 1, characterized in that The battery cell and the adjacent battery cell are the nth battery cell and the n+1th battery cell respectively; determining, based on the detection data of the battery cell and the detection data of the adjacent battery cell of the battery cell, that the relative change trend of the voltage of the battery cell and the adjacent battery cell conforms to the first change trend, comprises: When it is determined that the voltages of the battery cell and the adjacent battery cell meet a disconnection trigger condition according to the detection data of the battery cell and the detection data of the adjacent battery cell, it is determined that a relative change trend of the voltages of the battery cell and the adjacent battery cell meets a first change trend, wherein the disconnection trigger condition includes: The voltage of the n+1th battery cell collected the next time is greater than the sum of the voltage of the nth battery cell and the first voltage threshold, and the target average value of the voltages of the n+1th battery cell and the nth battery cell is greater than or equal to a second voltage threshold, and the absolute value of the difference between the target voltage and the target average value is less than or equal to a third voltage threshold, and the target voltage is 0.5 times the sum of the voltages of the n+1th battery cell and the nth battery cell collected the next time, and the voltage of the n+1th battery cell collected at the last time is greater than or equal to the sum of the voltage of the n+1th battery cell collected at the last time and the target voltage parameter, And the voltage of the nth battery cell collected at a previous time is greater than or equal to the sum of the voltage of the nth battery cell collected at a later time and a target voltage parameter.

6. The method according to claim 1, characterized in that The method further comprises: Creating a voltage data queue, wherein the voltage data queue includes x storage units, wherein x satisfies: x=p÷q, wherein p is the target duration, and q is the collection interval duration; Collect the single-cell voltage data of the battery at intervals of the collection interval; In the case where the voltage data queue has an idle storage unit, inserting the collected single-cell voltage data into the voltage data queue; in the case where the voltage data queue does not have an idle storage unit, deleting the single-cell voltage data inserted earliest in the voltage data queue, and inserting the collected single-cell voltage data into the voltage data queue; The obtaining of single-cell voltage data of the battery collected at least twice with a target time interval includes: when the voltage data queue does not have an idle storage unit, obtaining the single-cell voltage data inserted earliest and the single-cell voltage data inserted last in the voltage data queue.

7. The method according to claim 2, characterized in that The disabling of the battery cell comprises: disabling the battery balancing circuit of the battery cell and the adjacent battery cell, prohibiting the battery cell and the adjacent battery cell from participating in calculating the state of charge SOC of the battery, prohibiting the execution of the imbalance fault diagnosis of the battery, and prohibiting the execution of the voltage difference excessive protection diagnosis of the battery; And / or, enabling the battery cell includes: starting the battery balancing circuit of the battery cell and the adjacent battery cell, and enabling the battery cell and the adjacent battery cell to participate in calculating the state of charge SOC of the battery, and when all the battery cells of the battery are started, resuming the imbalance fault diagnosis of the battery and the excessive voltage difference protection diagnosis.

8. The method according to claim 2, characterized in that: The method further comprises: when the battery is initialized, setting a disconnection mark parameter of each cell of the battery as a first parameter; For each battery cell, when it is determined based on the detection data of the battery cell and the detection data of the adjacent battery cell that the voltage relative change trend of the battery cell and the adjacent battery cell meets the first change trend, disabling the battery cell includes: For each battery cell, if the disconnection mark parameter of the battery cell is the first parameter, then when it is determined according to the detection data of the battery cell and the detection data of the adjacent battery cells that the relative change trend of the voltage of the battery cell and the adjacent battery cells conforms to the first change trend, the battery cell is disabled and the disconnection mark parameter of the battery cell is updated to the second parameter; The disabled battery cell includes: the battery cell whose disconnection mark parameter is the second parameter.

9. A line detection device, characterized in that: Applied to a battery management system BMS, the device comprises: An acquisition module is used to acquire single-cell voltage data of a battery collected at least twice at a target time interval to obtain detection data of each cell, wherein the single-cell voltage data collected once includes the voltage of each cell of the battery, and the detection data includes the voltages collected twice for the cell; A determination module is used to disable each battery cell when it is determined, based on the detection data of the battery cell and the detection data of the adjacent battery cells, that a relative change trend of the voltages of the battery cell and the adjacent battery cells conforms to a first change trend, wherein the first change trend is a relative change trend of the voltages of two adjacent battery cells when one of the battery cells is disconnected.

10. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, for implementing the method steps described in any one of claims 1 to 8 when executing a program stored in a memory.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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