Line detection method, device and electronic equipment

Abstract

This application provides a circuit detection method, apparatus, and electronic device, relating to the field of battery cell protection technology. The circuit detection method includes: acquiring single-cell voltage data of a battery collected at least twice at a target time interval to obtain detection data for each cell. The single-cell voltage data collected in a single instance includes the voltage of each cell in the battery, and the detection data includes the voltage collected twice for the cell. For each cell, if, based on the detection data of the cell and the detection data of its adjacent cells, it is determined that the relative voltage change trend of the cell and its adjacent cells conforms to a first change trend, the cell is disabled. The first change trend is the relative voltage change trend of two adjacent cells when one cell has a broken circuit. This application effectively improves the reliability of battery break detection in scenarios where the battery is intermittently connected.

Description

Technical Field

[0001] This application belongs to the field of battery cell protection technology, specifically relating to a circuit detection method, device, and electronic equipment. Background Technology

[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 battery use during charging and discharging.

[0003] Current Battery Management Systems (BMS) can connect to each cell in the battery via voltage acquisition lines to collect the voltage of each cell, obtaining individual cell voltage data. This individual cell voltage data can then be used to determine if there are any abnormalities in the battery, allowing for timely implementation of battery protection measures. Among these measures, using individual cell voltage data for BMS disconnection detection, to determine if there are any open circuits in the battery's wiring, is a crucial method for battery protection.

[0004] Electric devices may experience intermittent loosening and tightening of battery terminals due to transportation and use disturbances. For example, the voltage acquisition line of the BMS may be intermittently connected to the battery terminals due to vibrations. This can cause momentary changes in individual cell voltage data when a terminal becomes loose, triggering the battery disconnection protection mechanism via the BMS disconnection detection. However, current battery disconnection protection, once triggered, renders the battery unusable, requiring return for repair. During repair, the battery terminals may become firmly connected again, preventing repair personnel from performing power-off analysis based on normal cell voltage data. Clearly, current BMS disconnection detection methods are unreliable in handling intermittent battery connection scenarios. Summary of the Invention

[0005] This application aims to provide a line detection method, apparatus, and electronic device, at least solving the problem of poor reliability of related line detection methods when dealing with intermittent battery conditions. To solve the above-mentioned technical problem, this application achieves the following:

[0006] In a first aspect, embodiments of this application provide a line detection method applied to a BMS, the method comprising:

[0007] Acquire single-cell voltage data of the battery at least twice with a target time interval to obtain detection data for each cell. The single-cell voltage data acquired in a single acquisition includes the voltage of each cell of the battery, and the detection data includes the voltage acquired twice for the cell.

[0008] For each battery cell, if the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cells, the battery cell is disabled. The first change trend is the relative voltage change trend of two adjacent battery cells when one battery cell has a broken wire.

[0009] Optionally, the method further includes: for the disabled 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 voltage change trend of the battery cell and the adjacent battery cells does not conform to a first change trend, enabling the battery cell.

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

[0011] Based on the detection data of the battery cell and the detection data of the adjacent battery cells, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a second change trend, which is the relative voltage change trend of two adjacent battery cells when neither of them has a broken wire.

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

[0013] Based on the detection data of the battery cell and the detection data of the adjacent battery cells, if it is determined that the voltage of the battery cell and the adjacent battery cells meet the recovery conditions, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a second change trend. The recovery conditions include: the absolute value of the voltage difference between the battery cell and the adjacent battery cells in the later acquisition is less than a first difference threshold, and the absolute value of the voltage difference between the battery cell and the adjacent battery cells in the later acquisition is less than the absolute value of the voltage difference between the battery cell and the adjacent battery cells in the previous acquisition.

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

[0015] Based on the detection data of the battery cell and the detection data of the adjacent battery cells, if it is determined that the voltage of the battery cell and the adjacent battery cells meet the open circuit triggering condition, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend, wherein the open circuit triggering condition includes:

[0016] The voltage of the (n+1)th cell in the next data acquisition is greater than the sum of the voltage of the nth cell and the first voltage threshold.

[0017] Furthermore, the target average voltage of the (n+1)th cell and the nth cell is greater than or equal to the second voltage threshold.

[0018] Furthermore, 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, where the target voltage is 0.5 times the sum of the voltages of the (n+1)th cell and the nth cell in the last data acquisition.

[0019] Furthermore, the voltage of the (n+1)th cell in the later acquisition is greater than or equal to the sum of the voltage of the (n+1)th cell in the previous acquisition and the target voltage parameter.

[0020] Furthermore, the voltage of the nth cell in the previous acquisition is greater than or equal to the sum of the voltage of the nth cell in the subsequent acquisition and the target voltage parameter.

[0021] Optionally, the method further includes:

[0022] Create a voltage data queue, which includes x storage units, where x satisfies: x = p ÷ q, where p is the target duration and q is the acquisition interval duration;

[0023] The voltage data of a single cell of the battery is collected at each collection interval.

[0024] If the voltage data queue has free storage units, the collected single-section voltage data is inserted into the voltage data queue; if the voltage data queue does not have free storage units, the earliest inserted single-section voltage data in the voltage data queue is deleted, and the collected single-section voltage data is inserted into the voltage data queue.

[0025] The step of acquiring 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 any free storage units, acquiring the earliest inserted single-cell voltage data and the last inserted single-cell voltage data in the voltage data queue.

[0026] Optionally, disabling the battery cell includes: 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 the calculation of the state of charge (SOC) of the battery, prohibiting the execution of the battery imbalance fault diagnosis, and prohibiting the execution of the battery differential pressure protection diagnosis.

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

[0028] Optionally, the method further includes: during battery initialization, setting the disconnection flag parameter of each cell of the battery to a first parameter;

[0029] For each battery cell, if the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cells, the battery cell is disabled, including:

[0030] For each battery cell, if the cell's disconnection flag parameter is the first parameter, then if the relative voltage change trend of the cell and the adjacent cells conforms to the first change trend based on the cell's detection data and the detection data of the adjacent cells, the cell is disabled and the cell's disconnection flag parameter is updated to the second parameter.

[0031] The term "targeting the disabled battery cell" includes: targeting the battery cell whose disconnection flag parameter is the second parameter.

[0032] Secondly, embodiments of this application provide a line detection device applied to a BMS, the device comprising:

[0033] The acquisition module is used to acquire single-cell voltage data of the battery at least twice with a target time interval, and obtain detection data for each cell. The single-cell voltage data acquired in a single acquisition includes the voltage of each cell of the battery, and the detection data includes the voltage acquired twice for the cell.

[0034] The determining module is configured to, for each battery cell, disable the battery cell if, based on the detection data of the battery cell and the detection data of its adjacent cells, the relative voltage change trend of the battery cell and its adjacent cells conforms to a first change trend. The first change trend is the relative voltage change trend of two adjacent battery cells when one of the battery cells has a broken wire.

[0035] Thirdly, embodiments of this application provide an electronic device including a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions, when executed by the processor, implementing the steps of the method described in the first aspect.

[0036] Fourthly, embodiments of this application provide a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect.

[0037] Fifthly, embodiments of this application provide a chip, the chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the method as described in the first aspect.

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

[0039] In this embodiment, by acquiring single-cell voltage data of the battery at least twice with a target time interval, detection data for each cell is obtained. The detection data for a single cell includes the voltage acquired twice. For each cell, this technical solution can determine whether the voltage change trend of the cell and its adjacent cells within the total time interval of the at least two acquisitions conforms to a first trend. If the relative voltage change trend of the cell and its adjacent cells conforms to the first trend, the cell is disabled. The first trend is the relative voltage change trend of two adjacent cells when one cell has a broken wire. Compared to related technologies that use instantaneous data to trigger overall battery disconnection protection, this technical solution can use overall data over a period of time to determine whether to disable a cell with a broken wire, thus providing disconnection protection for a single cell and effectively improving the reliability of battery disconnection detection in intermittent battery scenarios. Furthermore, the disconnection protection for individual cells does not require disabling the entire battery compared to related technologies, thus effectively improving battery utilization. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0041] Figure 1 This is a flowchart of a line detection method provided in an embodiment of this application;

[0042] Figure 2This is a flowchart of another line detection method provided in an embodiment of this application;

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

[0044] Figure 4 This is a schematic diagram illustrating the voltage change of a battery cell under a disconnection condition, provided in an embodiment of this application.

[0045] Figure 5 This is a flowchart of another line detection method provided in the embodiments of this application;

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

[0047] Figure 7 This is a flowchart of another line detection method provided in the embodiments of this application;

[0048] Figure 8 This is a block diagram of another line detection device provided in the embodiments of this application. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects 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 battery use during charging and discharging.

[0052] Current BMS can connect to each cell in the battery via voltage acquisition lines to collect the voltage of each cell and obtain the voltage data of a single cell.

[0053] Individual cell voltage data is one of the most important data sources for BMS (Battery Management System) management of batteries. When the voltage acquisition line is broken, the BMS will collect incorrect individual cell voltage data, affecting its subsequent judgment of the battery's health and safety. When a normal battery experiences a voltage acquisition line break, the voltage of adjacent cells at the break point will show a pattern of one cell's voltage increasing and the other's voltage decreasing. This will trigger battery protection mechanisms such as undervoltage, overvoltage, excessive voltage difference, and breakage, ultimately rendering the battery unusable. Therefore, repair personnel need to disassemble the battery pack to measure the true cell voltage and diagnose the voltage acquisition line breakage problem.

[0054] However, in electric equipment such as electric vehicles and electric tricycles, the battery terminals may become loose and intermittent 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 can cause a momentary change in the voltage data of a single cell when a terminal becomes loose, which may trigger the battery disconnection protection due to BMS disconnection detection.

[0055] However, current battery disconnection protection, once triggered, renders the battery unusable, necessitating factory repair. During repair, the battery terminals may reconnect, preventing technicians from performing power-off analysis based on normal cell voltage data. Clearly, current BMS disconnection detection methods are unreliable in intermittent battery operation scenarios. Furthermore, the probability of the battery mistakenly entering the disconnection protection state contributes to low battery usability.

[0056] Please refer to Figure 1 The diagram illustrates a flowchart of a line detection method provided in an embodiment of this application. The line detection method can be applied to a Battery Management System (BMS), which collects the voltage of each cell in the battery. Optionally, the line detection method can be executed by a processing device in the BMS. Alternatively, when the line detection method is applied to a vehicle, it can be executed by the vehicle's vehicle controller, which can obtain single-cell voltage data from the BMS to execute the method provided in this embodiment. It should be noted that the following explanation uses the example of the line detection method being executed by a BMS. Figure 1 As shown, the line detection methods include:

[0057] Step 101: Obtain single-cell voltage data of the battery from at least two data acquisitions at a target time interval to obtain the detection data for each cell. The single-cell voltage data acquired in a single data acquisition includes the voltage of each cell in the battery. The detection data includes the voltage acquired from two data acquisitions of the cell.

[0058] Optionally, the BMS can collect single-cell voltage data of the battery at target time intervals to obtain at least two adjacent collections of single-cell voltage data, thus obtaining the detection data for each cell. The detection data for a single cell includes the voltage collected by the BMS from the two data collections.

[0059] For example, suppose the BMS is used to acquire single-cell voltage data of a battery at two intervals of a target time for subsequent processing. And suppose the target time is 10 seconds. The BMS can acquire single-cell voltage data of the battery every 10 seconds, and after each acquisition, it obtains the single-cell voltage data from the previous acquisition and the current acquisition to obtain the detection data for each cell. The detection data for a single cell includes the voltage acquired by the BMS from two consecutive acquisitions of the cell's voltage.

[0060] In one optional implementation, the BMS is used to acquire single-cell voltage data of the battery from two samples collected at a target time interval, in order to perform subsequent processing. Based on this optional approach, such as... Figure 2 As shown, the line detection methods include:

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

[0062] In this embodiment, the number of storage units x (i.e., the length V_QUEUE_SIZE of the voltage data queue) in the voltage data queue (gVoltQueue) 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 cell of the battery in a single acquisition.

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

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

[0065] Step 202: Collect single-cell voltage data of the battery at intervals.

[0066] In this embodiment, the BMS can collect single-cell voltage data of the battery at intervals and determine whether the voltage data queue has free storage units to store the collected single-cell voltage data. Optionally, the collection interval can be 1 second, 0.5 seconds, 1.5 seconds, etc.

[0067] The tail-of-the-line data index can be shifted one position to the right after each storage of a single-section voltage data point (i.e., after occupying one storage unit) to indicate the next storage unit. For example, please refer to [link / reference]. Figure 3 In case B, where data is first inserted into the voltage data queue, the head data index is not updated. The tail data index shifts one position to indicate the second storage unit in the voltage data queue. Furthermore, in case C, where only the last storage unit remains uninserted in the voltage data queue, 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 head of the voltage data queue to indicate the first element. At this point, 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 checking if the data index at the tail 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 length of the element inserted into the voltage data queue is equal to the queue length. If the element length is equal to the queue length, the BMS determines that the voltage data queue does not have free storage units; if the element length is less than the queue length, the BMS determines that the voltage data queue has free storage units.

[0069] Step 203: If there are free storage units in the voltage data queue, insert the collected single-section voltage data into the voltage data queue.

[0070] In this embodiment of the 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 is shifted one position to the right accordingly.

[0071] Step 204: If there are no free storage units in the voltage data queue, delete the earliest inserted single-section voltage data in the voltage data queue and insert the collected single-section voltage data into the voltage data queue.

[0072] In this embodiment, if the voltage data queue has no free storage units, it indicates that the voltage data queue is full. The BMS can delete the earliest inserted single-section voltage data in the voltage data queue; that is, the BMS can discard the single-section voltage data indicated by the head data index and shift the head data index one position to the right. Then, the BMS inserts the collected single-section voltage data into the voltage data queue and shifts the tail data index one position to the right accordingly. For specific examples, please refer to [reference needed]. Figure 3 When the voltage data queue is full, the 10 storage units of the voltage data queue are written with numbers 1 to 10 sequentially, and both the tail data index and the head data index point to the first element of the voltage data queue. In case D, when 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 one position to the right to indicate the second element, data 2.

[0073] Based on this, step 101, which involves acquiring single-cell voltage data of the battery collected at least twice at a target time interval, may include: acquiring the earliest inserted single-cell voltage data and the last inserted single-cell voltage data in the voltage data queue when there are no free storage units in the voltage data queue, so as to obtain single-cell voltage data of the battery collected twice at a target time interval.

[0074] Optionally, the BMS can read the single-section voltage data indicated by the head data index and tail data index when there are no free storage units in the voltage data queue, so as to obtain the earliest inserted single-section voltage data and the last inserted single-section voltage data in the voltage data queue. For example, in a voltage data queue for... Figure 3 In scenario D, the BMS can read the first and second elements of the voltage data queue to obtain the single-cell voltage data of the battery collected at two intervals of the target duration.

[0075] Step 102: For each battery cell, based on the cell's detection data and the detection data of its adjacent cells, if the relative voltage change trend of the cell and its adjacent cells conforms to a first change trend, then disable the cell. The first change trend is the relative voltage change trend of two adjacent cells when one cell has a broken wire.

[0076] In this embodiment, after acquiring single-cell voltage data collected at least twice with a target time interval, the BMS can sequentially perform disconnection detection on each cell to determine whether to disable the cell. The disconnection detection for each cell includes: based on the cell's detection data and the detection data of its adjacent cells, determining whether the relative voltage change trend of the cell and its adjacent cells within the total time interval of the at least two acquisitions conforms to a first change trend.

[0077] If the relative voltage change trend of the cell and adjacent cells within the total duration of at least two data collection sessions conforms to a first trend, it indicates that the cell has been continuously disconnected during the total duration of at least two data collection sessions. The BMS can disable this cell to allow the battery to operate normally using other cells. Alternatively, if the relative voltage change trend of the cell and adjacent cells within the total duration of at least two data collection sessions does not conform to the first trend, it indicates that the cell has not been continuously disconnected during the total duration of at least two data collection sessions, and the cell does not have a disconnection fault. The BMS can continue to enable this cell to allow the battery to operate normally.

[0078] In this context, an adjacent cell can refer to one of two cells directly connected in series with the current cell. Optionally, an adjacent cell can be a downstream cell among the two cells directly connected in series with the current cell, and this downstream cell receives the output signal of the current cell. That is, an adjacent cell can be the cell among the two cells directly connected in series with the current cell that receives the output signal of the current cell. For example, suppose cells A, B, and C in a battery are connected in series. The adjacent cell of battery B can refer to cell C.

[0079] In this embodiment, the first trend is the relative voltage change trend of two adjacent battery cells when one cell has a broken wire. Optionally, the electronic device can simulate the relative voltage change trend of two adjacent battery cells when one cell has a broken wire to determine whether the battery has a broken wire. This can be achieved by connecting resistors of different values ​​in series on different voltage acquisition lines on the battery pack (i.e., the battery) to simulate different degrees of broken wire conditions. Then, the BMS collects single-cell voltage data of the battery under different degrees of broken wire conditions to obtain the relative voltage change trend of two adjacent battery cells when one cell has a broken wire.

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

[0081] It is easy to see that the voltage of cell B6 (the 6th cell) decreases 10 seconds after the voltage acquisition line of cell B6 is disconnected, while the voltage of cell B7 (the 7th cell) increases 10 seconds after the voltage acquisition line of cell B7 is disconnected. The voltage difference between cell B6 and cell B7 gradually increases 10 seconds after the voltage acquisition line of cell B7 is disconnected, and the voltage change curves of cell B6 and cell B7 have a certain degree of symmetry.

[0082] Because significant voltage changes occurred in cells B6 (6th cell) and B7 (7th cell) 10 seconds after the voltage acquisition line of cell B6 broke, this indicates that cell voltage data at least 10-second intervals can reflect whether a cell has experienced a break in its voltage distribution. Therefore, a target duration of 10 seconds is possible, allowing the BMS to use single-cell voltage data before and after 10 seconds to determine if a cell with a broken voltage distribution exists. Of course, the target duration can also be longer than 10 seconds, such as 11 or 12 seconds.

[0083] Based on this, in some embodiments, the BMS can store the first voltage change curves of two adjacent battery cells when one cell has a broken wire. After acquiring single-cell voltage data of the battery at least twice with a target time interval to obtain the detection data for each cell, the BMS can plot the voltage change curve of each cell. For each cell, the BMS calculates the similarity between the cell's voltage change curve and the voltage change curves of its adjacent cells, and the first voltage change curve, obtaining a similarity value.

[0084] If the similarity value is greater than the similarity threshold, indicating a high degree of similarity between the voltage change curves of the cell and its adjacent cells and the first voltage change curve, the relative voltage change trend of the cell and its adjacent cells is determined to conform to the first change trend, and the cell is disabled. Alternatively, if the similarity value is less than the similarity threshold, indicating a low degree of similarity between the voltage change curves of the cell and its adjacent cells and the first voltage change curve, the relative voltage change trend of the cell and its adjacent cells is determined to not conform to the first change trend, and the cell is enabled.

[0085] It should be noted that the more abundant the single-cell voltage data acquired by the BMS, the more abundant the voltage data of a single cell, and the more accurate the voltage change curve of the single cell can be plotted. Consequently, based on the plotted voltage change curve, the judgment result on whether the relative voltage change trend of the cell and adjacent cells conforms to the first change trend is more accurate, and the accuracy and reliability of cell breakage detection are higher.

[0086] For example, the BMS can acquire single-cell voltage data of the battery at 10 intervals at a target time interval and plot the voltage change curve of each cell. For each cell, the BMS calculates the similarity between the cell's voltage change curve and the voltage change curves of its adjacent cells, and a first voltage change curve to obtain a similarity value. Then, based on the relationship between the similarity data and a similarity threshold, it determines whether the relative voltage change trend of the cell and its adjacent cells conforms to the first change trend, thereby determining whether to disable the cell or continue to enable it.

[0087] In other embodiments, the battery cell and the adjacent battery cell are respectively the nth battery cell and the (n+1)th battery cell. The process by which the BMS determines that the relative voltage change trend of the battery cell and the adjacent battery cells within a target duration conforms to a first change trend, based on the detection data of the battery cell and the detection data of the adjacent battery cells, may include: if, based on the detection data of the battery cell and the detection data of the adjacent battery cells, it is determined that the voltage of the battery cell and the adjacent battery cells meets the disconnection triggering condition, then determining that the relative voltage change trend of the battery cell and the adjacent battery cells within the target duration conforms to the first change trend. The disconnection triggering condition includes:

[0088] The voltage of the (n+1)th cell in the next data acquisition is greater than the sum of the voltage of the nth cell and the first voltage threshold. Furthermore, the target average voltage of the (n+1)th and nth cells 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. Additionally, the voltage of the (n+1)th cell in the next data acquisition is greater than or equal to the sum of the voltage of the (n+1)th cell in the previous data acquisition and the target voltage parameter. The voltage of the nth cell in the previous data acquisition is greater than or equal to the sum of the voltage of the nth cell in the next data acquisition and the target voltage parameter. The target voltage is 0.5 times the sum of the voltages of the (n+1)th and nth cells in the next data acquisition.

[0089] In other words, 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, based on the detection data of the battery cell and its adjacent cells, the BMS determines that if the four conditions for disconnection triggering are met, and the relative voltage change trend of the battery cell and its adjacent cells within the target time period conforms to the first change trend, then the battery cell is disabled.

[0090] Wherein, V(n+1) represents the voltage of the (n+1)th cell in the last sampling. V(n) represents the voltage of the nth cell. VoltDifDisconnect represents the first voltage threshold. Vavg represents the target average voltage of the (n+1)th and nth cells. 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+1)th cell in the previous sampling. Volt_10s_Change represents the target voltage parameter. V(n)_last10s represents the voltage of the nth cell in the previous sampling.

[0091] In this embodiment, by acquiring single-cell voltage data of the battery at least twice with a target time interval, detection data for each cell is obtained. The detection data for a single cell includes the voltage acquired twice. For each cell, this technical solution can determine whether the voltage change trend of the cell and its adjacent cells within the total time interval of the at least two acquisitions conforms to a first trend. If the relative voltage change trend of the cell and its adjacent cells conforms to the first trend, the cell is disabled. The first trend is the relative voltage change trend of two adjacent cells when one cell has a broken wire. Compared to related technologies that use instantaneous data to trigger overall battery disconnection protection, this technical solution can use overall data over a period of time to determine whether to disable a cell with a broken wire, thus providing disconnection protection for a single cell and effectively improving the reliability of battery disconnection detection in intermittent battery scenarios. Furthermore, the disconnection protection for individual cells does not require disabling the entire battery compared to related technologies, thus effectively improving battery utilization.

[0092] Please refer to Figure 5 The diagram illustrates a flowchart of a line detection method provided in an embodiment of this application. The line detection method can be applied to a Battery Management System (BMS), which collects the voltage of each cell in the battery. Optionally, the line detection method can be executed by a processing device in the BMS. Alternatively, when the line detection method is applied to a vehicle, it can be executed by the vehicle's vehicle controller, which can obtain single-cell voltage data from the BMS to execute the method provided in this embodiment. It should be noted that the following explanation uses the example of the line detection method being executed by a BMS. Figure 5 As shown, the line detection methods include:

[0093] Step 501: Obtain single-cell voltage data of the battery from at least two data acquisitions spaced at a target time interval, to obtain the detection data for each cell. The single-cell voltage data acquired in a single data acquisition includes the voltage of each cell in the battery. The detection data includes the voltage acquired from two data acquisitions of the cell.

[0094] The explanation and implementation of this step can be found in step 101 above, and will not be repeated in this embodiment.

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

[0096] Optionally, the line detection method further includes: during battery initialization, setting the disconnection flag parameter of each battery cell to a first parameter. This first parameter indicates that the cell is in an enabled state, i.e., the battery is not disabled. After acquiring single-cell voltage data collected at least twice at a target time interval, the BMS can sequentially determine whether the disconnection flag parameter of each battery cell is the first parameter, so that if the disconnection flag parameter is the first parameter, the cell is determined to be an enabled cell; if the disconnection flag parameter is the second parameter, the cell is determined to be a disabled cell. For example, the first parameter can be 0; the second parameter can be 1.

[0097] Step 502: For cells that are not disabled, if the relative voltage change trend of the cell and its adjacent cells conforms to the first change trend, the cell is disabled.

[0098] In some embodiments of this application, for each battery cell, if the cell's disconnection flag parameter is a first parameter, then, based on the cell's detection data and the detection data of its adjacent cells, if it is determined that the relative voltage change trend of the cell and its adjacent cells within a target time period conforms to the first change trend, the cell is disabled, and the cell's disconnection flag parameter is updated to a second parameter. The explanation and implementation of this step can be found in step 102 above, and will not be elaborated upon in this embodiment.

[0099] Step 503: For a disabled battery cell, if the relative voltage change trend of the battery cell and its neighboring cells within the target time period does not conform to the first change trend, based on the detection data of the battery cell and the detection data of its neighboring cells, the battery cell is enabled.

[0100] In some embodiments of this application, for each cell, if the cell's disconnection flag parameter is the second parameter, then if, based on the cell's detection data and the detection data of its adjacent cells, it is determined that the relative change trend of the voltage of the cell and its adjacent cells within the target time period does not conform to the first change trend, the cell is activated and the cell's disconnection flag parameter 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 cell has a broken wire. After acquiring single-cell voltage data of the battery at least twice with a target time interval to obtain the detection data for each cell, the BMS can plot the voltage change curve of each cell. For each disabled cell, the BMS calculates the similarity between the cell's voltage change curve and the voltage change curves of its adjacent cells, and the first voltage change curve, to obtain a similarity value.

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

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

[0104] Based on the detection data of the battery cell and its adjacent cells, it was determined that the relative voltage change trend of the battery cell and its adjacent cells within the target time period conforms to a second change trend. The second change trend refers to the relative voltage change trend of two adjacent battery cells assuming no open circuits.

[0105] Optionally, the electronic device can pre-simulate the relative voltage change trend of two adjacent battery cells under the condition that neither cell is disconnected, in order to determine whether the battery is ready for activation. Specifically, the BMS collects single-cell voltage data of the battery under the condition that there is no disconnection, to obtain the relative voltage change trend of two adjacent battery cells under the condition that neither cell is disconnected.

[0106] For example, with Figure 4 In contrast, such as Figure 6 As shown, it illustrates a schematic diagram of the voltage change between two adjacent cells when the voltage acquisition line of a battery is not broken.

[0107] Figure 6 Given a battery with 13 cells, assuming that the voltage acquisition lines for the 6th and 7th cells are not disconnected, what are the voltage change curves for the 6th cell (B6) and the 7th cell (B7) if the battery is discharging normally? Figure 6 The horizontal axis of the voltage change curve represents time (in seconds), and the vertical axis represents voltage (in millivolts). Figure 6 It can be seen that the output voltage of cell B6 (the 6th cell) increased by 371mV within 2 seconds after the voltage acquisition line of cell B6 was disconnected and then closed, and by 371mV within 10 seconds after the line was closed. Correspondingly, the output voltage of cell B7 (the 7th cell) decreased by 373mV within 2 seconds after the voltage acquisition line of cell B6 was disconnected and then closed, and by 374mV within 10 seconds after the line was closed. The voltage difference between cell B6 and cell B7 was 6mV 2 seconds after the voltage acquisition line of cell B6 was closed, and 5mV 10 seconds after the line was closed.

[0108] It is easy to see that the voltage difference between cell B6 (6th cell) and cell B7 (7th cell) decreases 10 seconds after the voltage acquisition line of cell B6 is closed from being disconnected. The voltage difference between cell B6 and cell B7 10 seconds after the voltage acquisition line of cell B6 is closed is greater than the voltage difference between cell B6 and cell B7 10 seconds after the voltage acquisition line of cell B6 is closed.

[0109] Based on this, in some embodiments, the BMS can store second voltage change curves for two adjacent battery cells when neither cell experiences a break in the circuit. After acquiring single-cell voltage data from the battery at least twice at target intervals to obtain the detection data for each cell, the BMS can plot the voltage change curve for each disabled cell. For each disabled cell, the BMS calculates the similarity between the cell's voltage change curve, the voltage change curves of its adjacent cells, and the second voltage change curve to obtain a similarity value.

[0110] If the similarity value is greater than the similarity threshold, indicating that the voltage change curves of the cell and its adjacent cells are highly similar to the second voltage change curve, the relative voltage change trend of the cell and its adjacent cells is determined to conform to the second change trend, and the cell is activated.

[0111] It should be noted that the more abundant the single-cell voltage data acquired by the BMS, the more abundant the voltage data of a single cell, and the more accurate the voltage change curve of the single cell can be plotted. Consequently, based on the plotted voltage change curve, the judgment result on whether the relative voltage change trend of the cell and adjacent cells conforms to the second change trend is more accurate, the accuracy of cell breakage detection is higher, and the reliability is higher.

[0112] For example, the BMS can acquire single-cell voltage data of the battery at 10 intervals at a target time, and plot the voltage change curve of each cell. For each disabled cell, the BMS calculates the similarity between the cell's voltage change curve and the voltage change curves of its adjacent cells, and a second voltage change curve, obtaining a similarity value. Then, based on the relationship between the similarity data and a similarity threshold, it determines whether the relative voltage change trend of the cell and its adjacent cells conforms to the second change trend, thereby determining whether to enable the cell.

[0113] In other embodiments, the process by which the BMS determines that the relative voltage change trend of the battery cell and its adjacent cells within a target time period conforms to a second change trend, based on the detection data of the battery cell and the detection data of its adjacent cells, may further 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 last 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 last time is less than the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected the previous time.

[0116] That is, 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)). Where abs((V(n + 1) - V(n)) represents the absolute value of the voltage difference between the battery cell and its adjacent battery cell collected last 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 the previous time.

[0117] In the embodiments of the present application, after disabling a certain battery cell of the battery, it is also possible to restart the battery cell when it recovers from being disconnected by setting rules (for example, meeting the recovery condition). This solution further improves the reliability and accuracy of battery disconnection detection in the scenario where the battery has intermittent disconnection.

[0118] In some embodiments of the present application, the process of the BMS disabling the battery cell may include: disabling the battery balancing circuits of the battery cell and its adjacent battery cell, prohibiting the battery cell and its adjacent battery cell from participating in the calculation of 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 overvoltage difference protection diagnosis of the battery.

[0119] Optionally, when the circuit detection method is applied to a vehicle, the vehicle's Unified Diagnostic Services (UDS) includes a DTC status bit. Each bit in the DTC status bit represents a fault diagnosis status for the vehicle. Specifically, bit 6 of the DTC status bit is the imbalance fault diagnosis flag; the value of bit 6 indicates whether the imbalance fault diagnosis is complete. If the value of bit 6 is 0, it indicates that the imbalance fault diagnosis is complete. If the value of bit 6 is 1, it indicates that the imbalance fault diagnosis is incomplete. Bit 10 of the DTC status bit is the differential pressure overload protection diagnosis flag; the value of bit 10 indicates whether the differential pressure overload protection diagnosis is complete. If the value of bit 10 is 0, it indicates that the differential pressure overload protection diagnosis is complete. If the value of bit 10 is 1, it indicates that the differential pressure overload protection diagnosis is incomplete. Based on this, the process of disabling a battery cell by the BMS may include: disabling the battery equalization circuit of the battery cell and adjacent battery cells, prohibiting the battery cell and adjacent battery cells from participating in the calculation of the battery's SOC, prohibiting the execution of battery imbalance fault diagnosis, updating bit 6 of the DTC status bit to 0, prohibiting the execution of battery differential pressure protection diagnosis, and updating bit 10 of the DTC status bit to 0.

[0120] Thus, by disabling the battery balancing circuits of the cell and adjacent cells, the impact of abnormal voltage acquisition of the cell after disconnection on the BMS's battery balancing function can be avoided. Similarly, by disabling the participation of the cell and adjacent cells in calculating the battery's state of charge, the impact of abnormal voltage acquisition of the cell after disconnection on the calculation of the battery's SOC can be avoided. Likewise, by disabling the execution of battery imbalance fault diagnosis and battery differential voltage overload protection diagnosis, diagnostic errors in battery imbalance fault diagnosis and diagnostic errors in differential voltage overload protection diagnosis caused by abnormal voltage acquisition of the cell after disconnection can be avoided.

[0121] Accordingly, the process of enabling the battery cell by the BMS may include: starting the battery balancing circuit of the battery cell and adjacent cells, enabling the battery cell and adjacent cells to participate in the calculation of the battery's SOC, and resuming the execution of battery imbalance fault diagnosis and differential pressure protection diagnosis when all battery cells are started.

[0122] To facilitate understanding of the technical solution of this application, the circuit detection method provided in the embodiments of this application will be further illustrated by the following example. For example, an adjacent cell is a downstream cell of a cell. That is, if the cell is the nth cell, then the adjacent cell is the (n+1)th cell. Figure 7 As shown, the line detection methods include:

[0123] Create a two-dimensional circular array queue (i.e., a voltage data queue, gVoltQueue). The voltage data queue stores the individual cell voltage data for the last 10 seconds. The voltage data queue has a front index (frontIndex), which indicates the individual cell voltage data from 10 seconds ago. A rear index (rearIndex) indicates the storage location for the most recently acquired individual cell voltage data. Both the front and rear indices are 0.

[0124] The BMS collects individual cell voltage data of the battery every second.

[0125] The voltage data queue is checked for fullness by checking if the tail and head data indices point to the same element. If they do, the queue is full, the oldest inserted (i.e., oldest) single-cell voltage data is discarded. The head data index is shifted one position to the right, and a new single-cell voltage data is inserted into the storage unit indicated by the tail data index. The tail data index is then shifted one position to the right, and the queue data validity flag (gVQueueDataValid) is set to 1. This can be understood as shifting the tail data index one position every second. If the tail data index does not indicate the last element in the voltage data queue, shifting it one position means incrementing the tail data index by 1. If the tail data index indicates the last element, shifting it one position means moving it to the beginning of the queue, i.e., setting the tail data index to 0.

[0126] If the tail data index and the head data index do not point to the same element, the voltage data queue is detected to be not full. The queue data validity flag can be kept at 0, and a single voltage data segment can be inserted into the storage unit indicated by the tail data index in the voltage data queue, shifting the tail data index one position forward. Similar to the tail data index, if the head data index does not point to the last element in the voltage data queue, shifting the head data index one position forward means incrementing the head data index by 1. If the head data index points to the last element in the voltage data queue, shifting the head data index one position forward means moving the head data index to the first position in the voltage data queue, i.e., setting the head data index to 1.

[0127] Determine if the queue data validity flag is 1.

[0128] When the queue data validity flag is 1, retrieve the single-cell voltage data indicated by the data index at the head of the voltage data queue, as well as the most recently inserted single-cell voltage data, to trigger and restore the disconnection detection. Set n=1, 0<n≤m, where n is a positive integer and m is the total number of cells in the battery.

[0129] The triggering and recovery of the disconnection detection for the nth cell specifically includes: determining whether the disconnection flag parameter of the nth cell is 0.

[0130] When the disconnection flag parameter of the nth cell is 0, the voltage of the nth cell, V(n+1)_last10s, and the voltage of the nth cell, V(n)_last10s, are determined based on the single-cell voltage data indicated by the head-of-line data index, as well as the voltage of the nth cell, V(n+1), and the voltage of the nth cell, V(n)_last10s, in the latest inserted single-cell voltage data in the voltage data queue. The disconnection trigger 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 disconnection trigger condition is met, the disconnection flag parameter of the nth cell is set to 1, and n+1 (i.e., n++) is executed. It is then determined whether n equals m, so that if n is less than m, the disconnection detection trigger and recovery are performed for the (n+1)th cell. If the disconnection trigger condition is not met, n+1 (i.e., n++) is executed again, and it is determined whether n equals m, so that if n is less than m, the disconnection detection trigger and recovery are performed for the (n+1)th cell.

[0131] When the disconnection flag parameter of the nth battery cell is not 1, that is, when the disconnection flag parameter of the nth battery cell is 0, according to 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 of the nth battery cell (V(n)_last10s), the voltage V(n + 1) of the nth battery cell in the latest inserted single-cell voltage data in the voltage data queue, and the voltage V(n) of the nth battery cell, it is judged 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, the disconnection flag parameter of the nth battery cell is set to 0, execute n + 1 (that is, n++), and judge whether n is equal to m, so as to trigger and recover the disconnection 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 (that is, n++), and judge whether n is equal to m, so as to trigger and recover the disconnection 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, when the queue data valid flag is 0, and when n = m, if the disconnection flag parameters of the m battery cells of the battery change from 0 to 1, the disconnection fault flag bit is set to 1. For the battery cells with the disconnection fault flag parameter of 1, disable the battery equalization circuits of the battery cells and the adjacent battery cells, and prohibit the battery cells and the adjacent battery cells from participating in the calculation of the SOC of the battery, and prohibit the execution of the imbalance fault diagnosis of the battery, and update bit6 of the DTC status bit to 0, and prohibit the execution of the overvoltage difference protection diagnosis of the battery, and update bit10 of the DTC status bit to 0.

[0133] If the disconnection flag parameters of the m battery cells of the battery change from 1 to 0, the disconnection fault flag bit is set to 0. For the chips with the disconnection fault flag parameter of 0, start the battery equalization circuits of the battery cells and the adjacent battery cells, and enable the battery cells and the adjacent battery cells to participate in the calculation of the SOC of the battery, and when all the battery cells of the battery are started, resume the execution of the imbalance fault diagnosis and the overvoltage difference protection diagnosis of the battery.

[0134] In this embodiment, by acquiring single-cell voltage data of the battery at least twice with a target time interval, detection data for each cell is obtained. The detection data for a single cell includes the voltage acquired twice. For each cell, this technical solution can determine whether the voltage change trend of the cell and its adjacent cells within the total time interval of the at least two acquisitions conforms to a first trend. If the relative voltage change trend of the cell and its adjacent cells conforms to the first trend, the cell is disabled. The first trend is the relative voltage change trend of two adjacent cells when one cell has a broken wire. Compared to related technologies that use instantaneous data to trigger overall battery disconnection protection, this technical solution can use overall data over a period of time to determine whether to disable a cell with a broken wire, thus providing disconnection protection for a single cell and effectively improving the reliability of battery disconnection detection in intermittent battery scenarios. Furthermore, the disconnection protection for individual cells does not require disabling the entire battery compared to related technologies, thus effectively improving battery utilization.

[0135] Please refer to Figure 8 The diagram illustrates a block diagram of a line detection device according to an embodiment of this application. The line detection device can be applied to a BMS (Browser Management System). 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 at least twice with a target time interval, and obtain detection data for each cell. The single-cell voltage data acquired at one time includes the voltage of each cell of the battery, and the detection data includes the voltage acquired twice for the cell.

[0137] The determination module 802 is used to disable a battery cell if, based on the detection data of the battery cell and the detection data of its adjacent cells, the relative voltage change trend of the battery cell and its adjacent cells conforms to a first change trend. The first change trend is the relative voltage change trend of two adjacent battery cells when one battery cell has a broken wire.

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

[0139] Optionally, the determining module 802 is further configured to determine, based on the detection data of the battery cell and the detection data of the adjacent battery cells, that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a second change trend, wherein the second change trend is the relative voltage change trend of two adjacent battery cells under the condition that neither of them is disconnected.

[0140] Optionally, the determining module 802 is further configured to, based on the detection data of the battery cell and the detection data of its adjacent cells, determine that the voltage of the battery cell and its adjacent cells meets the recovery condition, and further determine that the relative voltage change trend of the battery cell and its adjacent cells conforms to a second change trend.

[0141] The recovery conditions include: the absolute value of the voltage difference between the cell and the adjacent cell in the last sample is less than the first difference threshold, and the absolute value of the voltage difference between the cell and the adjacent cell in the last sample is less than the absolute value of the voltage difference between the cell and the adjacent cell in the previous sample.

[0142] Optionally, the battery cell and the adjacent battery cell are respectively the nth battery cell and the (n+1)th battery cell; the determining module 802 is further configured to, based on the detection data of the battery cell and the detection data of the adjacent battery cells, determine that the voltage of the battery cell and the adjacent battery cells meets the open circuit triggering condition, determine that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend, wherein the open circuit triggering condition includes:

[0143] The voltage of the (n+1)th cell in the next sampling is greater than the sum of the voltage of the nth cell and the first voltage threshold, and the target average value of the voltages of the (n+1)th cell and the nth 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+1)th cell and the nth cell in the next sampling, and the voltage of the (n+1)th cell in the next sampling is greater than or equal to the sum of the voltage of the (n+1)th cell in the previous sampling and the target voltage parameter, and the voltage of the nth cell in the previous sampling is greater than or equal to the sum of the voltage of the nth cell in the next sampling and the target voltage parameter.

[0144] Optionally, the line testing device 800 also includes:

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

[0146] The data acquisition module is used to collect single-cell voltage data of the battery at intervals.

[0147] The write module is used to insert the collected single-section voltage data into the voltage data queue when there are free storage units in the voltage data queue, and to delete the earliest inserted single-section voltage data in the voltage data queue and insert the collected single-section voltage data into the voltage data queue when there are no free storage units in the voltage data queue.

[0148] The acquisition module 801 is also used to acquire the earliest inserted single-section voltage data and the last inserted single-section voltage data in the voltage data queue when there is no free storage unit in the voltage data queue.

[0149] Optionally, the determination module 802 is also used to disable the battery balancing circuit of the cell and adjacent cells, and to prohibit the cell and adjacent cells from participating in the calculation of the battery's SOC, and to prohibit the execution of battery imbalance fault diagnosis, and to prohibit the execution of battery differential pressure protection diagnosis.

[0150] Optionally, the determination module 802 is also used to start the battery balancing circuit of the cell and adjacent cells, enable the cell and adjacent cells to participate in the calculation of the battery's SOC, and resume the execution of battery imbalance fault diagnosis and differential pressure protection diagnosis when all cells of the battery are started.

[0151] Optionally, the line detection device 800 further includes: a setting module, used to set the disconnection flag parameter of each cell of the battery to a first parameter during battery initialization;

[0152] The determination module 802 is also used for each cell. If the cell's disconnection flag parameter is the first parameter, then based on the cell's detection data and the detection data of the cell's adjacent cells, if it is determined that the relative voltage change trend of the cell and the adjacent cells conforms to the first change trend, the cell is disabled and the cell's disconnection flag parameter is updated to the second parameter.

[0153] The determination module 802 is also used for cells with a breakage indicator parameter of the second parameter.

[0154] In this embodiment, by acquiring single-cell voltage data of the battery at least twice with a target time interval, detection data for each cell is obtained. The detection data for a single cell includes the voltage acquired twice. For each cell, this technical solution can determine whether the voltage change trend of the cell and its adjacent cells within the total time interval of the at least two acquisitions conforms to a first trend. If the relative voltage change trend of the cell and its adjacent cells conforms to the first trend, the cell is disabled. The first trend is the relative voltage change trend of two adjacent cells when one cell has a broken wire. Compared to related technologies that use instantaneous data to trigger overall battery disconnection protection, this technical solution can use overall data over a period of time to determine whether to disable a cell with a broken wire, thus providing disconnection protection for a single cell and effectively improving the reliability of battery disconnection detection in intermittent battery scenarios. Furthermore, the disconnection protection for individual cells does not require disabling the entire battery compared to related technologies, thus effectively improving battery utilization.

[0155] Optionally, the electronic device provided in this application embodiment includes a processor and a memory. The memory stores a program or instructions that can run on the processor. When the program or instructions are executed by the processor, they implement the various steps of the above-described circuit detection method embodiment and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0156] This application also provides a readable storage medium storing a program or instructions. When executed by a processor, the program or instructions implement the various processes of the above-described circuit detection method embodiments and achieve the same technical effects. To avoid repetition, these will not be described again here. The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory, random access memory, magnetic disk, or optical disk.

[0157] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described circuit detection method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0158] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

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

[0160] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0161] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A line detection method characterized by, Applied to a battery management system (BMS), the method includes: Acquire single-cell voltage data of the battery at least twice with a target time interval to obtain detection data for each cell. The single-cell voltage data acquired in a single acquisition includes the voltage of each cell of the battery, and the detection data includes the voltage acquired twice for the cell. For each battery cell, if the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cells, the battery cell is disabled. The first change trend is the relative voltage change trend of two adjacent battery cells when one battery cell has a broken wire.

2. The method of claim 1, wherein, The method further includes: For the disabled 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 voltage change trend of the battery cell and the adjacent battery cells does not conform to the first change trend, the battery cell is enabled.

3. The method according to claim 2, characterized in that, The step of determining, based on the detection data of the battery cell and the detection data of the adjacent battery cells, that the relative voltage change trend of the battery cell and the adjacent battery cells does not conform to the first change trend includes: Based on the detection data of the battery cell and the detection data of the adjacent battery cells, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a second change trend, which is the relative voltage change trend of two adjacent battery cells under the condition that there is no open circuit.

4. The method according to claim 3, characterized in that, The step of determining, based on the detection data of the battery cell and the detection data of the adjacent battery cells, that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a second change trend includes: Based on the detection data of the battery cell and the detection data of its adjacent cells, if it is determined that the voltages of the battery cell and its adjacent cells meet the recovery conditions, then it is determined that the relative voltage change trend of the battery cell and its adjacent cells conforms to the second change trend. The recovery conditions include: the absolute value of the voltage difference between the cell and the adjacent cell in the later acquisition is less than a first difference threshold, and the absolute value of the voltage difference between the cell and the adjacent cell in the later acquisition is less than the absolute value of the voltage difference between the cell and the adjacent cell in the previous acquisition.

5. The method according to claim 1, characterized in that, The battery cell and the adjacent battery cell are respectively the nth battery cell and the (n+1)th battery cell; the step of determining that the relative voltage change trend of the battery cell and the adjacent battery cell conforms to a first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cell includes: Based on the detection data of the battery cell and the detection data of the adjacent battery cells, if it is determined that the voltage of the battery cell and the adjacent battery cells meet the open circuit triggering condition, it is determined that the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend, wherein the open circuit triggering condition includes: The voltage of the (n+1)th cell in the next data acquisition is greater than the sum of the voltage of the nth cell and the first voltage threshold. Furthermore, the target average voltage of the (n+1)th cell and the nth cell is greater than or equal to the second voltage threshold. Furthermore, 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, where the target voltage is 0.5 times the sum of the voltages of the (n+1)th cell and the nth cell in the last data acquisition. Furthermore, the voltage of the (n+1)th cell in the later acquisition is greater than or equal to the sum of the voltage of the (n+1)th cell in the previous acquisition and the target voltage parameter. Furthermore, the voltage of the nth cell in the previous acquisition is greater than or equal to the sum of the voltage of the nth cell in the subsequent acquisition and the target voltage parameter.

6. The method according to claim 1, characterized in that, The method further includes: Create a voltage data queue, which includes x storage units, where x satisfies: x = p ÷ q, where p is the target duration and q is the acquisition interval duration; The voltage data of a single cell of the battery is collected at each collection interval. If the voltage data queue has free storage units, the collected single-section voltage data is inserted into the voltage data queue; if the voltage data queue does not have free storage units, the earliest inserted single-section voltage data in the voltage data queue is deleted, and the collected single-section voltage data is inserted into the voltage data queue. The step of acquiring 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 any free storage units, acquiring the earliest inserted single-cell voltage data and the last inserted single-cell voltage data in the voltage data queue.

7. The method according to claim 2, characterized in that, The disabling of the battery cell includes: 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 the calculation of the state of charge (SOC) of the battery, prohibiting the execution of the battery imbalance fault diagnosis, and prohibiting the execution of the battery differential pressure protection diagnosis. And / or, enabling the battery cell includes: activating the battery balancing circuit of the battery cell and the adjacent battery cell, enabling the battery cell and the adjacent battery cell to participate in calculating the state of charge (SOC) of the battery, and resuming the execution of the battery imbalance fault diagnosis and the differential pressure protection diagnosis when all the battery cells are activated.

8. The method according to claim 2, characterized in that, The method further includes: during battery initialization, setting the disconnection flag parameter of each cell of the battery to a first parameter; For each battery cell, if the relative voltage change trend of the battery cell and the adjacent battery cells conforms to a first change trend based on the detection data of the battery cell and the detection data of the adjacent battery cells, the battery cell is disabled, including: For each battery cell, if the cell's disconnection flag parameter is the first parameter, then if the relative voltage change trend of the cell and the adjacent cells conforms to the first change trend based on the cell's detection data and the detection data of the adjacent cells, the cell is disabled and the cell's disconnection flag parameter is updated to the second parameter. The term "targeting the disabled battery cell" includes: targeting the battery cell whose disconnection flag parameter is the second parameter.

9. A circuit testing device, characterized in that, The device is used in a battery management system (BMS) and includes: The acquisition module is used to acquire single-cell voltage data of the battery at least twice with a target time interval, and obtain detection data for each cell. The single-cell voltage data acquired in a single acquisition includes the voltage of each cell of the battery, and the detection data includes the voltage acquired twice for the cell. A determining module is configured to disable a battery cell if, based on the detection data of the battery cell and the detection data of its adjacent cells, the relative voltage change trend of the battery cell and its adjacent cells conforms to a first change trend. The first change trend is the relative voltage change trend of two adjacent battery cells when one of the battery cells has a broken wire.

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, when executing a program stored in memory, implements the steps of the method described in any one of claims 1 to 8.

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

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