Battery fault handling method and apparatus

Abstract

The application provides a battery fault processing method and device, and relates to battery management technology; the method comprises the following steps: identifying voltage abnormalities of a battery collector managed cell group, determining a fault cell pair with adjacent cells and a high-low voltage characteristic; determining a fault type of the fault cell pair based on voltage parameters obtained by balancing the fault cell pair and a preset fault determination condition; the fault type comprises a disconnection fault and a water vapor fault. Through the application, water vapor faults and disconnection faults can be effectively distinguished.

Description

Technical Field

[0001] This application relates to battery management technology, and more particularly to a battery fault handling method and apparatus. Background Technology

[0002] Within the sealed structure of the battery pack, the Battery Information Collector (BIC) uses an Analog Front End (AFE) chip to sample the voltage of individual cells in real time, ensuring the safety and balance of battery charging and discharging.

[0003] In related technologies, to achieve voltage fault detection in battery data acquisition devices, the equalization method combined with the chip's own diagnostic mechanism is mainly used to detect and determine open circuit faults. Specifically, by activating the cell equalization circuit to collect the equalization voltage, and combining parameters such as the voltage difference between the cells before and after equalization and the extreme voltage values ​​of individual cells, suspected open circuit faults are judged and continuously confirmed, ultimately completing the identification of open circuit faults.

[0004] However, during chip packaging or protective processes (such as applying adhesive or spraying conformal coating), if the ambient humidity is high or the process is not completely dried, moisture may remain between chip pins or within the conformal coating layer. This moisture can also cause voltage abnormalities. Based on known detection and judgment methods, it is impossible to distinguish between voltage abnormalities and open circuit faults caused by this type of moisture, thus making it impossible to effectively identify moisture faults. Summary of the Invention

[0005] This application provides a battery fault handling method and apparatus to effectively identify water vapor faults.

[0006] In a first aspect, this application provides a battery fault handling method, the method comprising:

[0007] Based on the identification of voltage anomalies in the cell groups managed by the battery collector, faulty cell pairs that are adjacent and exhibit a high-low voltage characteristic are identified.

[0008] Based on the voltage parameters obtained from the equalization process of the faulty cell pair and the preset fault determination conditions, the fault type of the faulty cell pair is determined; the fault type includes open circuit fault and moisture fault.

[0009] In one possible implementation, determining the fault type based on the voltage parameters obtained from the equalization processing of the faulty cell pair and preset fault determination conditions includes:

[0010] If the faulty battery cell pair meets any of the preset fault determination conditions, it is determined to be a disconnection fault; the preset fault determination conditions include: the faulty battery cell pair has the disconnection fault or is in the disconnection confirmation process, and the equalization voltage of any cell in the voltage parameters of the faulty battery cell pair is less than a preset voltage.

[0011] If the faulty battery cell does not meet the preset fault determination conditions, it is determined to be a water vapor fault.

[0012] In one possible implementation, the voltage parameter is determined in the following manner:

[0013] Based on the equalization circuit of the first cell in the faulty cell pair after it is turned on, the equalization voltage of the first cell is determined.

[0014] Based on the equalization circuit of the second cell in the faulty cell pair after the circuit is turned on, the equalization voltage of the second cell is determined.

[0015] The voltage parameters are determined based on the balanced voltage of the first cell and the balanced voltage of the second cell.

[0016] In one possible implementation, the voltage anomaly identification of the cell group managed by the battery collector includes:

[0017] The effective average voltage of the cells is determined based on the individual cell voltage of each cell in the cell group.

[0018] When the effective average voltage of the battery cell is not less than a preset threshold, the voltage of each consecutive adjacent battery cell pair in the battery cell group is sequentially identified as abnormal.

[0019] In one possible implementation, the method further includes:

[0020] If the effective average voltage of the battery cell is less than the preset judgment threshold and there is historically locked water vapor fault information, then the current voltage of the target faulty battery cell pair is determined according to the preset rules; the target faulty battery cell pair is the faulty battery cell pair corresponding to the historically locked formal water vapor fault.

[0021] And / or, if multiple sets of selectable faulty cell pairs are selected in the voltage anomaly identification, the faulty cell pair is determined from the multiple sets of selectable faulty cell pairs based on the cell number;

[0022] And / or, if the number of selectable faulty cell pairs reaches a preset severe fault threshold, it is determined to be a severe fault of the battery collector, and an alarm message is reported to the battery management controller.

[0023] In one possible implementation, determining the current voltage of the target faulty cell pair according to a preset rule includes:

[0024] Based on the total voltage of the cell management module of the battery collector, determine the average voltage corresponding to the total voltage of the cell management module;

[0025] If the normal average voltage of the battery cell group is higher than the sum of the average voltage and the preset compensation value, then the average voltage corresponding to the total voltage of the battery cell management module is corrected based on the preset compensation value, and the compensated total voltage of the battery cell management module is determined based on the corrected average voltage.

[0026] Based on the compensated total voltage of the cell management module, the cumulative total voltage of the non-abnormal cells in the cell group, the total number of cells in the cell group, and the number of non-abnormal cells, the inverse average voltage of the faulty cell pair is determined.

[0027] Based on the validity determination result of the inverse average voltage, the current voltage of the target faulty cell pair is determined accordingly.

[0028] In one possible implementation, the method further includes:

[0029] The number of faults is accumulated for the faulty battery cell pairs identified as having moisture faults.

[0030] If the cumulative number of faults does not reach the preset cumulative number, the faulty battery cell pair is identified as the suspected moisture fault.

[0031] If the cumulative number of faults reaches the preset cumulative number, then at least one of the following is executed: locking the faulty cell pair as the formal water vapor fault, storing the water vapor fault information in the storage unit, and activating the water vapor fault protection strategy in response to the formal water vapor fault state duration reaching a preset duration; the water vapor fault protection strategy includes at least one of the following: reducing the battery charging cutoff voltage by a first preset value, reducing the discharge cutoff voltage by a second preset value, and uploading fault-related data to the monitoring platform.

[0032] In one possible implementation, the step of accumulating the number of faults for the battery cell pairs determined to have the moisture fault includes:

[0033] Each time the faulty battery cell pair is determined to have a moisture fault, the cumulative fault count is incremented by 1, and the current voltage of the faulty battery cell pair is determined according to a preset rule;

[0034] If the current fault is not identified as a water vapor fault, the cumulative number of faults will be reset to zero, and the current sampled voltage of the faulty cell will be used as the current voltage.

[0035] Secondly, this application provides a battery fault handling device, the device comprising:

[0036] The identification module is used to identify voltage anomalies based on the cell groups managed by the battery collector, and to identify adjacent faulty cell pairs that exhibit a high-low voltage characteristic.

[0037] The identification module is also used to determine the fault type of the faulty battery cell pair based on the voltage parameters obtained from the equalization processing of the faulty battery cell pair and the preset fault judgment conditions; the fault type includes open circuit fault and moisture fault.

[0038] Thirdly, this application provides an electronic device, including at least one processor and a memory communicatively connected to the processor;

[0039] The memory stores computer-executed instructions;

[0040] The processor executes computer execution instructions stored in the memory to implement the method as described in any of the first aspects.

[0041] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any of the first aspects.

[0042] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in any of the first aspects.

[0043] This application provides a battery fault handling method and apparatus. The method proposes that during battery application, adjacent faulty cell pairs are first screened out by voltage anomaly identification to accurately locate the fault investigation range. Then, equalization operation is performed on the faulty cell pair and exclusive voltage parameters are collected. Finally, based on preset fault judgment conditions, the method can accurately distinguish between open circuit faults and moisture faults, thereby achieving effective identification of moisture faults. This effectively solves the problems of being unable to distinguish between voltage anomalies and open circuit faults caused by moisture and being unable to effectively identify moisture faults. Attached Figure Description

[0044] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0045] Figure 1A A schematic diagram illustrating the principle of a water vapor fault provided in an embodiment of this application;

[0046] Figure 1B This is a schematic diagram illustrating an application scenario of a battery fault handling method provided in an embodiment of this application.

[0047] Figure 2A schematic flowchart illustrating a battery fault handling method provided in an embodiment of this application;

[0048] Figure 3 This is a schematic diagram of the voltage anomaly identification process provided in an embodiment of this application;

[0049] Figure 4 A flowchart illustrating the fault type differentiation provided in this application embodiment;

[0050] Figure 5 This is a schematic diagram of the structure of a battery fault handling device provided in an embodiment of this application;

[0051] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0052] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0053] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0054] In the sealed structure of the battery pack, the Battery Information Collector (BIC) is the core component for sampling the voltage of individual cells. Its integrated Analog Front End (AFE) chip is directly connected to the electrodes of each individual cell, and is responsible for real-time, high-precision sampling of the voltage of individual cells. The sampled data is uploaded to the Battery Management Controller (BMC) in real time, providing data support for the execution of core strategies such as battery charge and discharge control, remaining capacity calculation, and equalization management, and directly ensuring the charging and discharging safety, cycle life and operational balance of the battery pack.

[0055] Because battery packs operate under complex conditions such as vehicles and energy storage for extended periods, and because they are sealed structures with relatively stable internal humidity environments, it is difficult to quickly troubleshoot and repair costs are high if the BIC or AFE chip malfunctions. Therefore, the reliability of the voltage sampling of the BIC is of paramount importance.

[0056] In related technologies, to achieve voltage fault detection in battery data acquisition devices and ensure the accuracy of sampling data, the equalization method combined with the AFE chip's own diagnostic mechanism is mainly used to detect and determine open circuit faults in the sampling line. Specifically, by controlling the AFE chip to activate the equalization circuit of the target battery cell, the equalization voltage of the cell after equalization is activated is collected. At the same time, the voltage difference of the cell before and after equalization, the highest and lowest values ​​of the single cell voltage, and other extreme parameters are compared. First, a suspected open circuit fault is determined, and then confirmed through multiple continuous samplings. Finally, the open circuit fault is identified and reported so that corresponding maintenance or protection strategies can be implemented subsequently.

[0057] However, during the AFE chip packaging or BIC module protection processes (such as adhesive sealing and conformal coating), if the production environment has high humidity, process parameters are not properly controlled, or drying is incomplete, moisture can easily remain between the AFE chip pins, between the pins and the substrate, or inside the conformal coating layer on the chip surface. This residual moisture cannot evaporate on its own in the sealed environment of the battery pack and will form an equivalent series resistance between the chip pins, causing abnormal voltages of adjacent individual cells collected by the AFE chip. This type of voltage abnormality is similar in characteristics to voltage abnormalities caused by a break in the sampling circuit.

[0058] Specifically, Figure 1A This is a schematic diagram illustrating the principle of a water vapor fault, as provided in an embodiment of this application. Figure 1A As shown, Cn and Cn+1 on the left represent two adjacent individual battery cells, and the box on the right represents the AFE chip, which is the core unit in the BIC used for voltage sampling and equalization control. Swn and Swn+1 are the equalization control switches for the corresponding cells Cn and Cn+1, used to turn on or off the equalization circuit of the corresponding cells; Rn is the equalization resistor for cell Cn, connected in series with the equalization switch Swn to form an equalization discharge circuit; R0, R1, and R2 are the sampling resistors or voltage divider resistors inside the AFE chip, participating in the sampling and signal acquisition of the cell voltage; the positive and negative terminals of cells Cn and Cn+1 are connected to the corresponding sampling pins of the AFE chip through sampling lines to achieve real-time acquisition of the cell voltage.

[0059] Based on this, when moisture remains between the pins of the AFE chip or within the conformal coating, a simulated moisture series resistance is formed between the sampling circuits of adjacent cells Cn and Cn+1. This equivalent resistance changes the current distribution of the cell voltage sampling path: the sampling currents i1 and i2 of cell Cn+1 are shunted due to the voltage division effect of the moisture equivalent resistance, causing the sampling voltage of Cn+1 to be abnormally pulled down; the sampling current i3 of cell Cn is abnormal due to the change in circuit impedance, causing the sampling voltage of Cn to be abnormally raised; ultimately, the sampling voltages of adjacent cells Cn and Cn+1 exhibit an abnormal characteristic of one being high and the other low, which is highly similar to the voltage anomaly caused by a sampling line open circuit fault.

[0060] The equalization method based on known technologies, combined with the chip's own diagnostic mechanism, can only identify open circuit faults. It cannot distinguish between voltage abnormalities caused by moisture and open circuit faults, thus failing to effectively identify moisture faults. This results in moisture faults remaining hidden for a long time, continuously causing voltage sampling distortion, interfering with the BMC's judgment of the battery status, affecting the accuracy of battery charge and discharge management, and in severe cases, may even cause safety hazards such as battery overcharging and over-discharging due to incorrect sampling data.

[0061] Therefore, embodiments of this application provide a battery fault handling method and apparatus to solve the above-mentioned problems. Specifically, the method of this application proposes to first identify voltage anomalies in the cell group managed by the battery collector and filter out adjacent faulty cell pairs within the sampling range; then, to perform a balancing operation on the faulty cell pairs and collect the voltage parameters of each cell in the faulty cell pair after balancing is enabled; finally, based on the voltage parameters and preset fault judgment conditions, to determine the fault type, namely, a wire breakage fault or a moisture fault.

[0062] It is understood that the battery fault handling method of this application is applicable to any battery application scenario. For example, as described in the background section above, the method of this application can be used in the battery management process of electric vehicle power batteries. Figure 1B This is a schematic diagram illustrating an application scenario of a battery fault handling method provided in an embodiment of this application, such as... Figure 1B As shown, the method of this application is executed by the battery management controller in the electric vehicle.

[0063] Specifically, during the driving, charging, or stationary operation of an electric vehicle, the battery management controller receives real-time voltage sampling data of individual cells in the corresponding cell group uploaded by the battery data acquisition unit. It monitors the voltage data of the cell group in real time and identifies voltage anomalies, filtering out adjacent cell pairs (i.e., faulty cell pairs) that exhibit voltage sampling anomalies from the sampling range. For the selected adjacent faulty cell pair, the battery management controller sends an equalization control command to the battery data acquisition unit, controlling the AFE chip inside the battery data acquisition unit to activate the equalization circuit of the corresponding cell (i.e., control...). Figure 1A The equalization switches Swn and Swn+1 in the battery are switched on and off. At the same time, the real-time voltage parameters of each cell in the faulty cell after equalization is turned on are collected and fed back to the battery management controller.

[0064] The battery management controller compares and analyzes the collected equalization voltage parameters with preset fault judgment conditions (such as equalization voltage threshold, voltage change trend, etc.) to determine the specific fault type of the faulty cell pair, distinguishing between a sampling line breakage fault and a moisture fault caused by residual moisture on the AFE chip pin, so as to implement corresponding fault handling and protection strategies for different faults and ensure the stable operation of the power battery.

[0065] In the above process, by performing anomaly identification and equalization verification on adjacent faulty cell pairs, it is possible to accurately distinguish between voltage anomalies caused by moisture and traditional open circuit faults, avoiding misjudgment or missed judgment due to sampling distortion caused by moisture, improving the reliability and stability of power battery fault identification, ensuring accurate voltage sampling, and thus ensuring the charging and discharging safety of electric vehicles, the accuracy of power estimation, and the reliability of vehicle operation.

[0066] It should be understood that, in the above process, the executing entity of the method of this application can also be any device capable of acquiring battery data and having data processing and computing capabilities, such as a vehicle controller or a cloud server; this embodiment does not limit this. Furthermore, the application scenarios of the method of this application can also be other scenarios, such as battery management in energy storage power stations, battery management in portable power supplies, and power battery management in industrial equipment; this embodiment does not limit these scenarios.

[0067] The following detailed description, with reference to the accompanying drawings and using any electronic device as the implementing entity, outlines some embodiments of the battery fault handling method of this application. Where the embodiments do not conflict, the following embodiments and features thereof can be combined with each other.

[0068] This application provides a battery fault handling method. Figure 2 This is a flowchart illustrating a battery fault handling method provided in an embodiment of this application, as shown below. Figure 2 As shown, the method in this application embodiment includes:

[0069] S201. Based on the voltage anomaly identification of the cell group managed by the battery collector, identify the faulty cell pair that is adjacent and has a voltage difference of one high and one low.

[0070] Specifically, the battery collector identifies voltage anomalies in the cell groups within its sampling range. The sampling range is all cell groups managed by the current battery collector. The electronic device acquires the real-time sampling voltage of each individual cell in the cell group, compares the voltage of each pair of adjacent cells, and determines whether they are faulty cell pairs based on the voltage difference characteristics.

[0071] In this embodiment, the electronic device collects the voltage of each individual cell in the cell group and determines the effective average voltage of the cells based on the individual cell voltages. Furthermore, voltage anomaly identification is performed based on the effective average voltage. Specifically, when the effective average voltage is not less than a preset threshold, voltage anomaly identification is performed sequentially on the voltages of each consecutive adjacent cell pair in the cell group.

[0072] More specifically, in this embodiment, when the electronic device obtains the voltage of each individual cell in the cell group, it removes the highest, second-highest, lowest, and second-lowest voltages from each individual cell and then performs an average calculation to obtain the effective average cell voltage. Next, the electronic device compares the effective average cell voltage with a preset threshold value corresponding to the battery pack to which the cell group belongs. If the effective average cell voltage is greater than or equal to the preset threshold value, it sequentially performs a high-low characteristic determination on each pair of consecutive adjacent cells in the cell group.

[0073] The preset threshold values ​​vary depending on the battery pack type. Specifically, they are engineering experience values ​​calibrated by combining the cell platform voltage characteristics, the minimum safe SOC boundary in different temperature ranges, and sampling error margin. For example, the threshold can be set based on the temperature-SOC curve. Considering factors such as the SOC not being too low, the threshold can be set based on the temperature-SOC curve. For example, for ternary lithium batteries, the set value is 3.4V when the battery pack temperature is ≥15℃ and 3.5V when the battery pack temperature is <15℃; for lithium iron phosphate batteries, the set value is around 3.2V.

[0074] Furthermore, in this embodiment, the determination method for the "one high, one low" characteristic is as follows: among two adjacent battery cells, if the sampling voltage of one cell is significantly higher than the effective average voltage of the battery cell, and the sampling voltage of the other cell is significantly lower than the effective average voltage of the battery cell, then the cell is determined to have the "one high, one low" characteristic if this voltage difference condition is met. More specifically, in this embodiment, if the sampling voltage of a battery cell is greater than the sum of the effective average voltage of the battery cell and 60mV, then the sampling voltage of the battery cell is considered to be significantly higher than the effective average voltage of the battery cell; if the sampling voltage of a battery cell is less than the difference between the effective average voltage of the battery cell and 100mV, then the sampling voltage of the battery cell is considered to be significantly lower than the effective average voltage of the battery cell.

[0075] In this embodiment, when two adjacent cells (cell i and cell i+1) have a sampled voltage greater than the sum of the effective average voltage of the cell and 60mV and a sampled voltage less than the difference between the effective average voltage of the cell and 100mV, or when a sampled voltage of cell i is less than the difference between the effective average voltage of the cell and 100mV and a sampled voltage of cell i+1 is greater than the sum of the effective average voltage of the cell and 60mV, the two adjacent cells are considered to be a faulty cell pair.

[0076] It should be understood that in practical applications, 60mV and 100mV can be replaced with other values, as long as they can effectively distinguish between normal voltage fluctuations in the battery cell and voltage anomalies caused by moisture faults, and satisfy the voltage difference judgment logic of one high and one low. For example, they can be 50mV and 90mV, 70mV and 110mV. This embodiment does not limit this.

[0077] In practical applications, the effective average voltage of the battery cell can also be calculated by averaging after removing the highest and lowest voltages, or by averaging all voltages directly; the characteristic of one high and one low can also be determined by setting the voltage difference between adjacent battery cells to exceed a preset voltage difference threshold, or by setting one to be higher than the average by a certain percentage and the other to be lower than the average by a certain percentage, etc. This embodiment does not limit this.

[0078] In addition, in practical applications, besides first calculating the effective average voltage of the battery cell and identifying voltage anomalies based on the effective average voltage of the battery cell, anomalies can also be identified by directly comparing the voltage differences of adjacent battery cells and judging the slope. This application does not limit this approach.

[0079] Furthermore, in practical applications, electronic devices may not directly collect the voltage of each individual cell in the battery pack, but may obtain the voltage of each individual cell in the battery pack by interacting with a data acquisition device. This application does not limit this.

[0080] The voltage anomaly identification method provided in this embodiment first calculates the effective average voltage by removing the highest, second-highest, lowest, and second-lowest voltages, thus avoiding interference from extreme voltage values ​​and making the reference voltage more closely match the actual working state of the battery cell. Then, by comparing the effective average voltage with a preset judgment threshold, it accurately excludes operating conditions such as low SOC and low voltage that are not suitable for anomaly identification, avoiding misidentification caused by small voltage differences in the battery cell itself and susceptibility to noise interference. Finally, it uses clear 60mV and 100mV voltage difference thresholds to determine high and low characteristics, giving the screening of faulty battery cell pairs a quantitative standard, effectively improving the stability, accuracy, and feasibility of early identification of water vapor faults.

[0081] S202. Based on the voltage parameters obtained from the equalization processing of the faulty cell pair and the preset fault judgment conditions, determine the fault type of the faulty cell pair.

[0082] The fault types include wire breakage and moisture failure.

[0083] In this embodiment, the electronic device controls the corresponding equalization switch inside the AFE chip to turn on, thereby activating the equalization circuit between the faulty battery cell and other cells, achieving equalization operation. It should be understood that the equalization circuit of a battery cell consists of the equalization switches (such as Swn and Swn+1) inside the AFE chip, the equalization resistor (such as Rn), and the battery cell itself. Figure 1A As shown, cell Cn corresponds to equalization switch Swn and equalization resistor Rn, and cell Cn+1 corresponds to equalization switch Swn+1. When the corresponding equalization switch is closed, the cell forms a discharge circuit through the equalization resistor to achieve equal discharge of a single cell. This equalization circuit is the core circuit of the battery collector to achieve cell voltage equalization and fault diagnosis.

[0084] Specifically, in this embodiment, the electronic device sequentially and individually activates the equalization circuits of the first and second cells in the faulty cell pair; then, based on the equalization circuit of the first cell in the faulty cell pair after it is activated, the equalization voltage of the first cell is determined; based on the equalization circuit of the second cell in the faulty cell pair after it is activated, the equalization voltage of the second cell is determined; and based on the equalization voltages of the first and second cells, the voltage parameters are determined.

[0085] More specifically, in identification Figure 1A When the cell pairs Cn and Cn+1 shown are faulty cell pairs, the electronic equipment sequentially closes the equalization switch Swn and collects the voltage of cell Cn after equalization is activated; then it closes the equalization switch Swn+1 and collects the voltage of cell Cn+1 after equalization is activated. The equalization voltages collected twice are used as voltage parameters.

[0086] In practical applications, the two equalization circuits of the faulty cell pair can be opened simultaneously, or the equalization circuits can be opened in other sequences; the voltage parameters can also be the voltage difference before and after equalization, the voltage change rate, etc., and this application does not limit this.

[0087] In addition, in practical applications, the activation control action of the equalization circuit can be performed not only by this electronic device, but also by other peripheral devices with circuit on / off control capabilities such as battery collectors and independent equalization control units. This application does not limit this.

[0088] In this embodiment, the equalization circuits of each cell are activated sequentially and individually, completely avoiding mutual interference between the equalization circuits of two cells. This ensures that the collected equalization voltage accurately reflects the sampling characteristics of a single cell in the equalization state, providing a reliable and interference-free voltage data basis for distinguishing between open circuit faults and moisture faults based on preset fault judgment conditions. At the same time, using the equalization voltage directly as the core voltage parameter simplifies the data acquisition and processing process, adapts to the real-time requirements of the battery management system, and effectively solves the problem of sampling data distortion caused by simultaneous equalization of multiple cells, thus making it impossible to effectively distinguish fault types.

[0089] It should be understood that a broken wire fault is a fault caused by an open circuit or poor contact in the battery cell sampling circuit, resulting in abnormal sampling; a moisture fault is a fault caused by residual moisture in the AFE chip pins or the conformal coating, resulting in abnormal sampling voltage.

[0090] In this embodiment, the preset fault determination conditions include: the faulty battery cell pair has a disconnection fault or is in the disconnection confirmation process; and the equalization voltage of any cell in the voltage parameters of the faulty battery cell pair is less than a preset voltage. The electronic device determines a disconnection fault when the faulty battery cell pair meets any of the preset fault determination conditions; and determines a moisture fault when the faulty battery cell pair does not meet the preset fault determination conditions.

[0091] Specifically, the existence of a disconnection state or being in the disconnection confirmation process means that the faulty cell has met the disconnection judgment criteria (such as the voltage difference between the cell before and after equalization exceeding 1V, or the single cell voltage value >4950mV or <50mV) in the disconnection detection process of the battery management system and has been marked as a disconnection fault, or is in the process of continuously sampling and confirming the disconnection fault, and the system has been continuously monitoring the disconnection fault.

[0092] Specifically, from a circuit principle perspective, when the cell circuit is completely disconnected, the theoretical value of the equalization voltage obtained after activating the equalization circuit is 0V. However, in actual hardware circuits, there are objective influences such as sampling noise, line leakage current, and electromagnetic interference, making it impossible to collect an absolute zero-volt voltage. Therefore, in this embodiment, the preset voltage is set to 50mV, which is the common judgment value for disconnection detection in the battery management system. Correspondingly, if the equalization voltage is less than 50mV, it indicates that the cell's equalization circuit cannot be formed normally due to the open circuit in the sampling line, and there is no effective voltage input at the cell's sampling end, thus it is judged as a disconnection fault. Under a moisture fault, the equivalent series resistance formed by moisture can still allow the equalization circuit to form a path, and the equalization voltage will not be lower than the preset voltage. Moreover, the equalization voltage under a moisture fault exhibits completely different characteristics from that under a disconnection fault. The specific theoretical calculation process is as follows:

[0093] Based on the electrical principle model of water vapor faults, a 1KΩ equivalent water vapor resistance is connected in series between Cn and SWn+1. Theoretical calculations clearly demonstrate this characteristic: assuming line resistance R1=R2=1Ω and equalization resistance Rn=1000Ω. Therefore, during normal sampling of Cn+1: sampling voltage V=Vcn+1-VR2-VR1=Vcn+1-i1R2-i1R1=Vcn+1-2i1; after equalization of the Cn+1 battery cell is activated: sampling voltage V'=Vcn+1-[R2(i1+i2)-i2Rn]-R2i1=Vcn+1-2i1+1000Ω. i2, we can conclude that V' > V, that is, the voltage value collected after Cn+1 is balanced is higher than the normal sampling value; after balancing of Cn cell is balanced: its sampling value is consistent with the normal sampling channel, but due to the voltage division effect of the balancing resistor, the balanced sampling value will be lower than the normal sampling value.

[0094] In practical applications, the preset voltage can also be set directly to 0V, and the judgment can be made based on the voltage change law of the ideal sampling circuit. Under this circuit model, if there is a water vapor fault, the adjacent faulty cells satisfy the fixed voltage division calculation formula: VSampleCelln=Vcelln+(1 / 3)VCelln+1; VSampleCelln+1=Vcelln+1-(1 / 3)VCelln+1. Wherein, Vcelln and Vcelln+1 represent the actual voltage of the two adjacent faulty cells, respectively, and VSampleCelln and VSampleCelln+1 represent the sampling voltage actually collected by the sampling end after the equalization circuit of the corresponding cell is turned on. This voltage relationship is derived based on the circuit voltage division principle and can be used as the standard voltage characteristic for identifying water vapor faults.

[0095] It should be understood that if a faulty battery cell exhibits abnormal characteristics of one high and one low signal and does not meet the criteria for a broken wire fault, the cause of a broken wire can be ruled out. Therefore, the abnormality can be determined to be caused by moisture, i.e., it is determined to be a moisture fault.

[0096] In practical applications, the disconnection status can also be determined by continuous multiple sampling confirmations and equalization current detection; the preset voltage can be adaptively set according to different cell types and different sampling circuits, but this embodiment does not limit it.

[0097] In this embodiment, the historical state of the system disconnection detection process is combined with the quantified equalization voltage threshold to form a dual judgment standard. This not only makes full use of the existing disconnection detection resources of the battery management system, but also realizes the quantitative judgment of disconnection faults through a preset voltage of 50mV. The judgment logic is simple and direct, requiring no additional hardware equipment. The software algorithm alone can accurately distinguish between disconnection faults and moisture faults, filling the industry gap where moisture faults cannot be identified and are easily confused with disconnection faults.

[0098] Meanwhile, through dedicated identification of moisture faults, it was clarified that the fault was caused by sampling abnormalities due to residual moisture on the chip pins / conformal paint, rather than a fault in the battery pack itself. This avoids misjudging moisture faults as open circuit faults, which could trigger stringent vehicle battery management measures such as limiting battery pack power and stopping charging and discharging. It prevents normal vehicle operation from being interfered with by sampling faults that are not inherent to the battery pack itself. Moreover, the determination process does not require complex data analysis and can quickly output fault type results, meeting the real-time fault diagnosis needs of the battery management system and balancing fault identification accuracy with vehicle operation continuity.

[0099] In the method provided in this embodiment, the abnormal battery cells are first screened by identifying adjacent faulty battery cells with one high and one low voltage. Unlike the traditional random differential pressure screening and single-cell abnormality judgment methods, this method uses the inherent adjacent differential pressure distortion characteristics of water vapor faults and open circuit faults to accurately locate potential fault locations, avoids indiscriminate traversal judgment of all battery cells in the vehicle, and effectively reduces the amount of computation for fault identification.

[0100] Simultaneously, by applying equalization processing to faulty battery cells and collecting equalization voltage parameters, and relying on the differentiated electrical response characteristics under equalization conditions, the system achieves the classification and determination of open circuit faults and moisture faults in conjunction with preset fault determination conditions. Compared to judgment logics that can only identify line open circuit faults and cannot distinguish moisture sampling anomalies, this solution utilizes the equalization condition to amplify the voltage difference between the two types of faults. It can accurately separate two different fault mechanisms from the same source of voltage anomaly phenomena, solving the technical pain point that the two types of faults have the same external sampling appearance and are prone to misjudgment.

[0101] Furthermore, the overall judgment logic in this embodiment is based on the electrical characteristics of the battery cell itself, without the need to add additional hardware detection devices such as humidity sensors and detection circuits. While controlling hardware costs and retaining the original battery data acquisition architecture, it improves the differentiation and accuracy of battery fault diagnosis, providing a reliable pre-judgment basis for subsequent differentiated fault management, voltage correction and protection strategy execution.

[0102] It should be understood that when the effective average voltage of the battery cell is low, the voltage difference within the cell itself is small, making it susceptible to noise sampling and resulting in poor overall reliability of anomaly identification. Furthermore, moisture has little impact on sampling at low charge levels; even if a moisture fault exists, it will not significantly interfere with the normal operation of the battery system. Additionally, the deviation caused by moisture in the sampling signal is not prominent under low charge conditions. Therefore, when the effective average voltage of the battery cell is less than the preset threshold, voltage anomaly identification is unnecessary.

[0103] Furthermore, it should be understood that during the voltage identification process, there may be multiple sets of faulty cell pairs, meaning that multiple adjacent cell pairs with one high and one low voltage abnormality may appear simultaneously in a cell group. Therefore, in this embodiment, when the electronic device filters out multiple sets of selectable faulty cell pairs during voltage anomaly identification, it determines the faulty cell pair from the multiple sets of selectable faulty cell pairs based on the cell number.

[0104] Specifically, multiple selectable faulty cell pairs refer to two or more adjacent abnormal cell pairs identified within the same sampling period. In this embodiment, when the number of selectable faulty cell pairs reaches a preset severe fault threshold, it is directly determined as a severe fault of the battery collector, and an alarm message is reported to the battery management controller.

[0105] More specifically, the electronic device only performs balancing, fault type determination, and fault count accumulation steps for the pair of faulty cells with the earliest cell number. "Earliest cell number" refers to the cell with the smallest cell number (e.g., if cells 1 & 2 and cells 3 & 4 are both faulty cell pairs, cells 1 & 2 are processed first). Furthermore, in this embodiment, the preset severe fault threshold is a configurable threshold for the number of groups. Reaching this threshold indicates that the AFE chip of the battery data acquisition unit may have experienced widespread sampling anomalies or hardware failures, which cannot be corrected using the fault handling process of this solution.

[0106] In practical applications, the group with the latest number and the most obvious voltage abnormality can be selected for priority processing; the preset serious fault threshold can be flexibly set according to the total number of battery cells; alarm information may include fault code, fault location, fault level, handling suggestions, etc., which are not limited in this application.

[0107] It should be understood that when the effective average voltage of the cells in the current identification period is less than the preset judgment threshold, although there is no need to identify voltage anomalies, there may be a pair of faulty cells corresponding to a historically locked formal water vapor fault. That is, the target faulty cell pair that was locked as a formal water vapor fault in the previous identification period. At this time, the fault is a continuous anomaly rather than a transient interference, and the cell sampling voltage has been distorted and cannot truly reflect the actual voltage state of the cell. Therefore, it is necessary to determine the current voltage of the target faulty cell pair according to the preset rules, that is, to update the cell voltage value to obtain the true voltage reference value of the cell and ensure that the voltage data obtained by the battery management system is always valid.

[0108] In this embodiment, the electronic device updates the current voltage of the target faulty cell pair according to the voltage back-calculation process: based on the total voltage of the cell management module of the battery collector, the average voltage corresponding to the total voltage of the cell management module is determined; if the normal average voltage of the cell group is higher than the sum of the average voltage and the preset compensation value, the average voltage corresponding to the total voltage of the cell management module is corrected based on the preset compensation value, and the compensated total voltage of the cell management module is determined based on the corrected average voltage; based on the compensated total voltage of the cell management module, the cumulative total voltage of the non-abnormal cells in the cell group, the total number of cells in the cell group and the number of non-abnormal cells, the back-calculated average voltage of the faulty cell pair is determined; based on the validity determination result of the back-calculated average voltage, the current voltage of the target faulty cell pair is determined accordingly.

[0109] More specifically, the detailed process of voltage inverse calculation is as follows:

[0110] 1. Collect the total voltage (Vblock voltage) of the cell management module of the battery collector, and calculate the average Vblock voltage based on the number of voltage sampling channels of the cell management module. Specifically, the Vblock voltage is the total module voltage of the cell group managed by the battery collector. The number of voltage sampling channels of the cell management module is consistent with the total number of cells managed by the collector. The average Vblock voltage of a single cell can be calculated by using the formula Vblock average voltage = total Vblock voltage ÷ number of voltage sampling channels.

[0111] 2. Identify non-abnormal cells in the cell group. Abnormal cells include cells identified as disconnected, cells in the disconnection confirmation process, and cells with invalid voltages caused by register default values. Calculate the cumulative total voltage of the non-abnormal cells, the number of normal cells, and the normal average voltage. Specifically, the electronic device first filters out cells marked as disconnected or in the disconnection confirmation process through the battery management system's fault detection records and cell voltage sampling data identification. Simultaneously, it removes cells with sampled voltages at register default values ​​or without actual physical meaning; all such cells are determined to be abnormal. The remaining unmarked cells with sampled voltages of valid values ​​are determined to be non-abnormal. Then, the real-time sampled voltages of all non-abnormal cells are summed to obtain the cumulative total voltage of the non-abnormal cells. The number of non-abnormal cells is counted to obtain the number of normal cells. Finally, the normal average voltage of the non-abnormal cells is calculated using the formula: Normal Average Voltage = Cumulative Total Voltage of Non-Abnormal Cells ÷ Number of Normal Cells.

[0112] 3. Perform accuracy compensation on the Vblock average voltage. The preset compensation value is 3mV. When the normal average voltage > Vblock average voltage + 3mV, the Vblock average voltage is compensated by 3mV. The compensated total Vblock voltage is (Vblock average voltage + 3mV) × number of voltage samples. In this embodiment, this compensation operation can correct the sampling accuracy error of the Vblock voltage (different AFE chips have different sampling accuracy; the actual test error is approximately a negative deviation Vnum). (4mV). It should be understood that different AFE chips have different sampling accuracies, and the preset compensation value can be adjusted according to the actual usage and test data.

[0113] 4. Calculate the reverse average voltage of the faulty cell pair. The calculation formula is: Reverse average voltage = (Compensated Vblock total voltage - Cumulative total voltage of non-abnormal cells) / (Total number of batteries - Number of normal batteries).

[0114] 5. The validity of the reverse-calculated average voltage is determined by the following criteria: reverse-calculated average voltage ≥ 4.3V, reverse-calculated average voltage ≤ 1.5V, and the difference between the reverse-calculated average voltage and the normal average voltage > 1V. If any one of these conditions is met, the reverse-calculated voltage is considered abnormal.

[0115] 6. When the validity determination result is normal, the voltage of the faulty cell pair is assigned to the average voltage of Vblock. When the determination result is abnormal, the water vapor abnormality status of the faulty cell pair is directly cancelled.

[0116] In practical applications, fault accumulation can be carried out by continuous accumulation, sliding window accumulation, etc.; the preset number of accumulations can be set according to the system response speed and reliability requirements; water vapor fault information can also include information such as temperature, SOC, and equilibrium status, which are not limited in this application.

[0117] Furthermore, in practical applications, voltage inversion can also employ methods such as model-based estimation, Kalman filtering, and historical data fitting. This application does not limit the specific implementation method. For example, an estimation method based on the cell charging and discharging model can be used. Based on parameters such as the cell's charging and discharging current, time, and temperature, combined with the cell's charging and discharging characteristic model, the actual voltage value of the faulty cell can be estimated, replacing the result of the Vblock voltage inversion, thus correcting the voltage of the faulty cell.

[0118] In the above settings, only the first faulty cell pair is processed, avoiding system resource consumption and data processing logic conflicts caused by processing multiple faults simultaneously. This ensures the orderly and efficient operation of the fault handling process and adapts to the resource limitations of the battery management system. When the number of faulty groups reaches a threshold, it is directly judged as a serious fault of the data acquisition unit and an alarm is triggered. This can quickly identify large-scale hardware anomalies of the data acquisition unit and promptly remind staff to replace the pack or perform repairs, preventing the fault from escalating and affecting the overall safety of the battery pack. Under low SOC conditions, voltage back-calculation is continuously performed on historically locked formal water vapor faults, ensuring that the battery management system can obtain effective voltage data under all operating conditions. This ensures the normal execution of the core control strategy and solves the problems of system burden caused by processing multiple faults simultaneously and the inability to identify large-scale anomalies of the data acquisition unit in a timely manner.

[0119] In this embodiment, the voltage inversion process achieves overall estimation of the faulty cell voltage by collecting the total Vblock voltage, avoiding the influence of distorted voltage at the sampling end of the faulty cell, and making the inverted voltage more consistent with the actual working state of the cell. Through Vblock voltage accuracy compensation, the system error caused by chip sampling is corrected, improving the accuracy of the inverted voltage. Through clear validity judgment criteria, incorrect inverted voltages are avoided from being applied to the battery management system, ensuring the reliability of voltage inversion. Finally, the valid inverted voltage is assigned to the faulty cell, allowing the battery management system to execute core strategies such as charge and discharge control, SOC estimation, and equalization management based on real and valid voltage data. There is no need to adjust the normal management strategy of the vehicle's power battery due to sampling distortion caused by water vapor faults, ensuring that the vehicle's power output and charge and discharge functions are not affected by water vapor faults, and ensuring normal operation of the vehicle under all operating conditions such as driving and charging. At the same time, this process is executed automatically by the system without manual intervention, adapting to the automation requirements of vehicle battery management.

[0120] It should be understood that a single identification may be subject to momentary interference and voltage fluctuations, resulting in misjudgment. Therefore, as a further design, in this embodiment, the number of faults of the faulty cell pairs determined to be moisture faults is accumulated, and the suspected moisture faults or the actual moisture faults are identified based on the accumulated results, so as to distinguish between the suspected moisture faults of temporary anomalies and the actual moisture faults of real existence.

[0121] Specifically, if the cumulative number of faults does not reach the preset cumulative number, the faulty cell pair is identified as a suspected water vapor fault; if the cumulative number of faults reaches the preset cumulative number, at least one of the following is executed: locking the faulty cell pair as a formal water vapor fault, storing the water vapor fault information in the storage unit, and activating the water vapor fault protection strategy in response to the formal water vapor fault state duration reaching a preset duration; the water vapor fault protection strategy includes at least one of the following: reducing the battery charging cutoff voltage by a first preset value, reducing the discharge cutoff voltage by a second preset value, and uploading fault-related data to the monitoring platform.

[0122] Each time a faulty cell pair is determined to be a moisture fault, the cumulative fault count is incremented by 1, and the current voltage of the faulty cell pair is determined according to a preset rule; if the current fault is not determined to be a moisture fault, the cumulative fault count is cleared to zero, and the current sampled voltage of the faulty cell pair is used as the current voltage.

[0123] More specifically, in this embodiment, the preset cumulative count is set to 100. During the monitoring process, each time the electronic device identifies a faulty cell pair and classifies it as a moisture fault, the cumulative count is incremented by 1. Since the current identification is a moisture anomaly, not a misjudgment caused by momentary interference, the sampled voltage of the cell is distorted and cannot accurately reflect the actual voltage state of the cell. Therefore, it is necessary to update the current voltage of the faulty cell pair to obtain the true voltage reference value of the cell. In this embodiment, the electronic device also updates the current voltage of the faulty cell pair by performing a voltage inverse calculation process on the faulty cell.

[0124] If the current monitoring fails to identify a water vapor fault, it indicates that the previous voltage anomaly may have been a misjudgment caused by external factors such as transient electromagnetic interference or voltage fluctuations, and does not represent a real water vapor fault at the cell acquisition end. Therefore, the cumulative number of faults is cleared to zero, and the voltage reverse calculation process is stopped to avoid incorrectly correcting the voltage of normal cells and to prevent the reverse calculation voltage from affecting the normal control strategy of the battery management system.

[0125] When the cumulative number of faults reaches 100, the moisture fault is determined to be real and persistent, and it is locked as a formal moisture fault. If the cumulative number of faults has not reached the preset number, it is identified as a suspected moisture fault, and continuous monitoring can be performed. In this embodiment, the moisture fault information includes the fault location (cell number), fault occurrence time, cumulative number of faults, abnormal sampling voltage, etc.; the storage unit is an electrically erasable programmable read-only memory (EEPROM) for long-term storage of fault information for background big data monitoring and subsequent fault troubleshooting.

[0126] In practical applications, the preset cumulative count can be flexibly adjusted. Specifically, it can be configured and adjusted according to the actual operating conditions of the vehicle, the intensity of onboard electromagnetic interference, the accuracy of the battery sampling circuit, and the system fault response rate requirements. This embodiment does not impose any limitations on this. For example, in scenarios with stable road conditions, simple electromagnetic environment, and high sampling circuit accuracy, the preset cumulative count can be appropriately reduced to speed up fault confirmation. In scenarios with complex driving environments for commercial vehicles, strong electromagnetic interference, and easily fluctuating sampling signals, the preset cumulative count can be appropriately increased to further improve the accuracy of fault determination and reduce misjudgments caused by external interference.

[0127] In this embodiment, by accumulating 100 fault counts, false faults caused by external factors such as transient electromagnetic interference and voltage fluctuations can be effectively filtered out, effectively reducing the false judgment rate of water vapor faults, making the fault judgment results more consistent with the actual situation, and improving the credibility of water vapor fault identification. By distinguishing between suspected water vapor faults and actual water vapor faults, water vapor faults can be processed in a graded manner. Suspected water vapor faults are only continuously monitored, which can avoid excessive alarms and unnecessary voltage back-calculation operations. Actual water vapor faults are accurately locked and stored, which can ensure that faults are promptly monitored and subsequently processed. At the same time, the voltage back-calculation process is executed immediately after each water vapor fault is determined, which can promptly correct distorted sampling voltages and ensure that the voltage data obtained by the battery management system is valid. This solves the problem of the lack of a water vapor fault graded judgment mechanism and the susceptibility to false judgment due to transient interference in known technologies.

[0128] Furthermore, after the electronic device locks in the formal water vapor fault, it begins to monitor the duration of its continuous state. When the duration of the formal water vapor fault reaches the preset duration, the electronic device activates the water vapor fault protection strategy.

[0129] Specifically, in this embodiment, the electronic device starts the timing module to continuously time the moment the faulty cell is locked by the system as a formal water vapor fault, and obtains the time interval from the moment the fault is locked to the current moment in real time. This time interval is the duration of the formal water vapor fault state. In this embodiment, the timing process is implemented by the built-in timing unit of the battery management controller, which can accurately record the duration of the fault.

[0130] In this embodiment, when the duration of the continuous state reaches a preset duration, the electronic device reduces the battery charging cutoff voltage by a first preset value, lowering the upper limit voltage for battery charging; it also reduces the discharge cutoff voltage by a second preset value to prevent deep battery discharge; simultaneously, it uploads fault-related data such as the faulty cell number, the time of fault occurrence, and the cumulative number of faults to the monitoring platform to complete fault tracing and retention. This protection strategy is a minor fault-tolerant control measure, different from the hard power limiting and charge / discharge interruption logic for open circuit faults, improving battery operational safety without affecting the normal use of the vehicle.

[0131] More specifically, the preset duration is set to 5 seconds, the first preset value is 30mV, and the second preset value is 200mV, that is, the charging cutoff voltage is reduced by 30mV and the discharging cutoff voltage is reduced by 200mV. Fault-related data includes abnormal cell number, actual sampled voltage value of cell, voltage back-calculation result, fault lock-in time, fault duration, current temperature of battery pack and SOC, etc. After being uploaded to the monitoring platform, real-time big data monitoring of water vapor faults can be realized, which is convenient for subsequent fault investigation and data analysis.

[0132] In this embodiment, if the duration of the formal water vapor fault does not reach the preset duration of 5 seconds, the fault state will disappear (e.g., the water vapor abnormality state will be canceled). The timing will then stop immediately and the timing value will be cleared to zero. When the cell is subsequently locked as a formal water vapor fault again, the timing module will be restarted to ensure that the timing duration can truly reflect the actual duration of a single formal water vapor fault.

[0133] In practical applications, the first and second preset values ​​can be adaptively set according to the cell type, safety performance requirements, and charging and discharging strategies of the battery pack. For example, the charging cutoff voltage can be reduced by 20mV and the discharging cutoff voltage by 180mV, or the charging cutoff voltage can be reduced by 40mV and the discharging cutoff voltage by 220mV. The timing method can also be cumulative timing, that is, when the fault state is interrupted and reappears, the timing continues to accumulate on the basis of the previous timing without resetting to zero. This embodiment does not limit this.

[0134] Furthermore, the preset duration can also be flexibly adjusted and can be configured independently based on the vehicle's usage scenario, battery safety management level, and fault warning management intensity. This embodiment does not impose any limitations on this. For example, the preset duration can be appropriately shortened for daily commuting scenarios of passenger vehicles to activate flexible protection measures as early as possible; for scenarios with higher priority requirements for range, such as commercial vehicles and heavy-load conditions, the preset duration can be appropriately extended to reduce the impact of frequent triggering of protection strategies on the normal driving experience.

[0135] The method provided in this embodiment, by setting a preset duration, can avoid frequent execution of protection strategies due to brief recovery from moisture faults, ensuring the targeted execution of protection strategies. By reducing the charging cut-off voltage by 30mV and the discharging cut-off voltage by 200mV, it can effectively avoid overcharging and over-discharging problems of cells caused by slight deviations in the average voltage calculated by Vblock. While improving the safety of the battery pack under fault conditions, it only slightly reduces the charging and discharging cut-off voltages, without changing the core charging and discharging logic and power output of the power battery. It will not have a significant impact on normal vehicle operation, regular charging, and other usage scenarios, achieving a balance between fault safety protection and normal vehicle operation. By uploading fault-related data to the monitoring platform, remote monitoring and big data management of moisture faults are realized, making it convenient for staff to grasp the fault status of the battery pack in a timely manner and carry out subsequent fault investigation and repair work. At the same time, it provides a real data source for the process optimization of the battery data acquisition device and the training of fault early warning models.

[0136] Furthermore, the entire protection strategy requires no manual intervention and is executed automatically by the system, adapting to the automated operation requirements of the battery management system. This solves the problems of battery packs being prone to overcharging and over-discharging and the inability to remotely monitor fault status when moisture faults persist.

[0137] As can be seen from the above, the method provided in this embodiment achieves dedicated identification and accurate processing of water vapor faults in battery data acquisition devices through a complete process of precise voltage anomaly screening → equalization operation parameter acquisition → precise fault type differentiation → fault count accumulation and classification → voltage back-calculation correction. This fills the industry gap that currently only allows identification of open circuit faults and not water vapor faults. The entire method does not require any new hardware equipment and can be implemented only through software algorithm optimization. It is compatible with the mass production application requirements of existing battery management systems and has low modification costs.

[0138] Meanwhile, quantitative standards and judgment logic are set up for the entire process from fault identification to voltage correction, making the handling of water vapor faults executable and accurate. This effectively solves the problem that the inability to identify water vapor faults can easily lead to misjudgment as open circuit faults and trigger stringent management measures. Through accurate fault differentiation and effective voltage back calculation, the battery management system is ensured to always execute management strategies based on effective voltage data. There is no need to adjust the normal operation strategy of the vehicle's power battery due to water vapor, which is not a fault of the battery itself. This avoids interference of water vapor faults with normal vehicle driving, charging and other operating conditions from the process perspective. In addition, by setting up multiple sets of fault handling rules and low SOC operating condition handling rules, the method has stronger adaptability and can cover all operating conditions of the battery pack. This effectively improves the sampling reliability of the battery acquisition device and the operational safety and stability of the battery pack.

[0139] As a further detailed explanation of the voltage anomaly identification process, Figure 3 This is a schematic diagram of the voltage anomaly identification process provided in an embodiment of this application, as shown below. Figure 3 As shown, the voltage anomaly identification process is as follows: 1. Initiate moisture anomaly identification; 2. Collect the voltage of each individual cell in the battery cell group managed by the battery collector, remove the highest, second highest, lowest, and second lowest voltages, and calculate the effective average voltage of each cell corresponding to each BIC; 3. Determine whether the effective average voltage of the cell is greater than or equal to the set value (i.e., the preset judgment threshold, such as 3.4V for ternary lithium at ≥15℃ and 3.5V for <15℃, and approximately 3.2V for lithium iron phosphate). If yes, proceed to the next step; if no, determine not to perform anomaly identification, and further confirm whether there are locked faulty cell pairs. If so, directly enter the voltage reverse calculation flow. If no process is found, the process ends; 4. Perform a high-low characteristic judgment on consecutive adjacent cell pairs (cell i, cell i+1) in the cell group. The judgment criteria are Cell[i] > cell effective average voltage + 60mV and Cell[i+1] + 100mV < cell effective average voltage, or Cell[i+1] > cell effective average voltage + 60mV and Cell[i] + 100mV < cell effective average voltage; 5. Determine whether the above judgment criteria are met. If not, continue to judge the next group of cells. If yes, mark cell i and i+1 as faulty cell pairs and enter the fault differentiation process.

[0140] As a further detailed explanation of the fault differentiation process, Figure 4 This is a flowchart illustrating the fault type differentiation provided in the embodiments of this application, such as... Figure 4 As shown, the fault type differentiation process is as follows: 1. Start the fault differentiation process; 2. Only activate the equalization circuit for faulty battery number i, and read and record the voltage Celli_Bal after activating equalization; 3. Only activate the equalization circuit for faulty battery number i+1, and read and record the voltage Celli+1_Bal after activating equalization; 4. Determine whether the faulty cell pair is in a disconnected state or in the disconnection confirmation process. If so, record it as a disconnection fault and increment the fault count for moisture fault by 1. Otherwise, proceed to the next step; 5. Determine whether the equalization voltage is less than 50mV. If so, record it as a disconnection fault and end the process. Otherwise, record it as a moisture fault and increment the fault count for moisture fault by 1; 6. Determine whether the cumulative fault count has reached 100. If not, end the process and continue monitoring. If so, lock the moisture fault and store the fault record in EEPROM.

[0141] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0142] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0143] The above embodiments introduce a battery fault handling method from the perspective of process flow. The following embodiments introduce a battery fault handling device from the perspective of virtual module or virtual unit. For details, please refer to the following embodiments.

[0144] This application also provides a battery fault handling device for implementing the methods described in the above method embodiments. Figure 5 This is a schematic diagram of the structure of a battery fault handling device provided in an embodiment of this application, as shown below. Figure 5 As shown, in this embodiment, the battery fault handling device may include:

[0145] The identification module 51 is used to identify voltage anomalies based on the cell groups managed by the battery collector, and to identify adjacent faulty cell pairs with voltages that are one high and one low.

[0146] The identification module 51 is also used to determine the fault type of the faulty cell pair based on the voltage parameters obtained from the equalization processing of the faulty cell pair and the preset fault judgment conditions; the fault type includes open circuit fault and moisture fault.

[0147] In one possible implementation of this application embodiment, the identification module 51 is specifically used for:

[0148] If a faulty battery cell pair meets any of the preset fault determination conditions, it is determined to be a disconnection fault. The preset fault determination conditions include: the faulty battery cell pair has a disconnection fault or is in the disconnection confirmation process, and the equalization voltage of any cell in the voltage parameters of the faulty battery cell pair is less than the preset voltage.

[0149] If the faulty battery cell does not meet the preset fault judgment conditions, it is judged to be a moisture fault.

[0150] In one possible implementation of this application embodiment, the voltage parameter is determined in the following manner:

[0151] Based on the equalization circuit of the first cell after the faulty cell is turned on, the equalization voltage of the first cell is determined.

[0152] Based on the equalization circuit of the faulty cell after it is turned on, the equalization voltage of the second cell is determined.

[0153] The voltage parameters are determined based on the equalization voltage of the first cell and the equalization voltage of the second cell.

[0154] In one possible implementation of this application embodiment, the identification module 51 is specifically used for:

[0155] The effective average voltage of the cells is determined based on the individual cell voltages of each cell in the cell group.

[0156] When the effective average voltage of the battery cell is not less than the preset judgment threshold, the voltage of each consecutive adjacent battery cell pair in the battery cell group is sequentially identified as abnormal.

[0157] In one possible implementation of this application embodiment, the identification module 51 is further configured to:

[0158] If the effective average voltage of the battery cell is less than the preset judgment threshold and there is historically locked water vapor fault information, the current voltage of the target faulty battery cell pair is determined according to the preset rules; the target faulty battery cell pair is the faulty battery cell pair corresponding to the historically locked formal water vapor fault.

[0159] And / or, if multiple sets of selectable faulty cell pairs are selected in the voltage anomaly identification, the faulty cell pair is determined from the multiple sets of selectable faulty cell pairs based on the cell number;

[0160] And / or, if the number of selectable faulty cell pairs reaches a preset severe fault threshold, the battery collector is determined to be severely faulty, and an alarm message is reported to the battery management controller.

[0161] In one possible implementation of this application embodiment, the identification module 51 is specifically used for:

[0162] Based on the total voltage of the cell management module of the battery data acquisition unit, determine the average voltage corresponding to the total voltage of the cell management module;

[0163] If the normal average voltage of the battery cell group is higher than the sum of the average voltage and the preset compensation value, then the average voltage corresponding to the total voltage of the battery cell management module is corrected based on the preset compensation value, and the compensated total voltage of the battery cell management module is determined based on the corrected average voltage.

[0164] Based on the compensated total voltage of the cell management module, the cumulative total voltage of non-abnormal cells in the cell group, the total number of cells in the cell group, and the number of non-abnormal cells, the inverse average voltage of the faulty cell pair is determined.

[0165] Based on the validity determination result of the inverse average voltage, the current voltage of the target faulty cell pair is determined.

[0166] In one possible implementation of this application embodiment, the apparatus further includes a processing module 52, which is used for:

[0167] Equalization processing is performed on faulty battery cell pairs to obtain voltage parameters;

[0168] And / or, accumulate the number of faults for faulty cell pairs determined to be moisture faults in order to identify suspected moisture faults or formal moisture faults.

[0169] In one possible implementation of this application embodiment, the processing module 52 is specifically used for:

[0170] The number of faults is accumulated for each battery cell pair identified as having a moisture fault.

[0171] If the cumulative number of faults does not reach the preset cumulative number, the faulty battery cell pair is identified as a suspected moisture fault.

[0172] If the cumulative number of faults reaches the preset cumulative number, at least one of the following will be executed: lock the faulty cell pair as a formal water vapor fault, store the water vapor fault information in the storage unit, and activate the water vapor fault protection strategy in response to the formal water vapor fault state duration reaching the preset duration. The water vapor fault protection strategy includes at least one of the following: reducing the battery charging cutoff voltage to a first preset value, reducing the discharge cutoff voltage to a second preset value, and uploading fault-related data to the monitoring platform.

[0173] In one possible implementation of this application embodiment, the processing module 52 is specifically used for:

[0174] Each time a faulty cell pair is determined to have a moisture fault, the cumulative fault count is incremented by 1, and the current voltage of the faulty cell pair is determined according to a preset rule.

[0175] If the current fault is not determined to be a water vapor fault, the cumulative fault count will be reset to zero, and the current sampled voltage of the faulty cell will be used as the current voltage.

[0176] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.

[0177] This application provides an electronic device. Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, such as... Figure 6 As shown, Figure 6 The illustrated electronic device includes at least one processor 61 and a memory 62. The processor 61 and the memory 62 are connected, for example, via a bus 63. Optionally, the electronic device may also include a transceiver 64. It should be noted that in practical applications, the transceiver 64 is not limited to one, and the structure of this electronic device does not constitute a limitation on the embodiments of this application.

[0178] Processor 61 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 61 may also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0179] Bus 63 may include a pathway for transmitting information between the aforementioned components. Bus 63 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 63 may be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0180] The memory 62 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto.

[0181] The memory 62 stores computer execution instructions for implementing the scheme of this application, and the processor 61 controls the execution. The processor 61 executes the computer execution instructions stored in the memory 62 to implement the content shown in the foregoing method embodiments.

[0182] This application also provides a computer-readable storage medium, which may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. Specifically, the computer-readable storage medium stores computer-executable instructions, which are used to implement the methods in the above embodiments.

[0183] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the technical solution of the above method embodiments. Its implementation principle and technical effects are similar, and will not be repeated here.

[0184] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0185] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0186] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery fault handling method, characterized in that, The method includes: Based on the identification of voltage anomalies in the cell groups managed by the battery collector, faulty cell pairs that are adjacent and exhibit a voltage difference of one high and one low are identified. Based on the voltage parameters obtained from the equalization process of the faulty cell pair and the preset fault determination conditions, the fault type of the faulty cell pair is determined; the fault type includes open circuit fault and moisture fault.

2. The method according to claim 1, characterized in that, The determination of the fault type based on the voltage parameters obtained from the equalization processing of the faulty cell pair and preset fault determination conditions includes: If the faulty battery cell pair meets any of the preset fault determination conditions, it is determined to be a disconnection fault; the preset fault determination conditions include: the faulty battery cell pair has the disconnection fault or is in the disconnection confirmation process, and the equalization voltage of any cell in the voltage parameters of the faulty battery cell pair is less than a preset voltage. If the faulty battery cell does not meet the preset fault determination conditions, it is determined to be a water vapor fault.

3. The method according to claim 1 or 2, characterized in that, The voltage parameters are determined in the following manner: Based on the equalization circuit of the first cell in the faulty cell pair after it is turned on, the equalization voltage of the first cell is determined. Based on the equalization circuit of the second cell in the faulty cell pair after the circuit is turned on, the equalization voltage of the second cell is determined. The voltage parameters are determined based on the balanced voltage of the first cell and the balanced voltage of the second cell.

4. The method according to claim 1 or 2, characterized in that, The process of identifying voltage anomalies in the battery cell groups managed by the battery data acquisition device includes: The effective average voltage of the cells is determined based on the individual cell voltage of each cell in the cell group. When the effective average voltage of the battery cell is not less than a preset threshold, the voltage of each consecutive adjacent battery cell pair in the battery cell group is sequentially identified as abnormal.

5. The method according to claim 4, characterized in that, The method further includes: If the effective average voltage of the battery cell is less than the preset judgment threshold and there is historically locked water vapor fault information, then the current voltage of the target faulty battery cell pair is determined according to the preset rules; the target faulty battery cell pair is the faulty battery cell pair corresponding to the historically locked formal water vapor fault. And / or, if multiple sets of selectable faulty cell pairs are selected in the voltage anomaly identification, the faulty cell pair is determined from the multiple sets of selectable faulty cell pairs based on the cell number; And / or, if the number of selectable faulty cell pairs reaches a preset severe fault threshold, it is determined to be a severe fault of the battery collector, and an alarm message is reported to the battery management controller.

6. The method according to claim 5, characterized in that, Determining the current voltage of the target faulty cell pair according to preset rules includes: Based on the total voltage of the cell management module of the battery collector, determine the average voltage corresponding to the total voltage of the cell management module; If the normal average voltage of the battery cell group is higher than the sum of the average voltage and the preset compensation value, then the average voltage corresponding to the total voltage of the battery cell management module is corrected based on the preset compensation value, and the compensated total voltage of the battery cell management module is determined based on the corrected average voltage. Based on the compensated total voltage of the cell management module, the cumulative total voltage of the non-abnormal cells in the cell group, the total number of cells in the cell group, and the number of non-abnormal cells, the inverse average voltage of the faulty cell pair is determined. Based on the validity determination result of the inverse average voltage, the current voltage of the target faulty cell pair is determined accordingly.

7. The method according to claim 1 or 2, characterized in that, The method further includes: The number of faults is accumulated for the faulty battery cell pairs identified as having moisture faults. If the cumulative number of faults does not reach the preset cumulative number, the faulty battery cell pair is identified as a suspected moisture fault. If the cumulative number of faults reaches the preset cumulative number, then at least one of the following is executed: locking the faulty cell pair as a formal water vapor fault, storing the water vapor fault information in the storage unit, and activating the water vapor fault protection strategy in response to the formal water vapor fault state duration reaching a preset duration; the water vapor fault protection strategy includes at least one of the following: reducing the battery charging cutoff voltage by a first preset value, reducing the discharge cutoff voltage by a second preset value, and uploading fault-related data to the monitoring platform.

8. The method according to claim 7, characterized in that, The process of accumulating the number of faults for battery cell pairs identified as having moisture faults includes: Each time the faulty battery cell pair is determined to have a moisture fault, the cumulative fault count is incremented by 1, and the current voltage of the faulty battery cell pair is determined according to a preset rule; If the current fault is not identified as a water vapor fault, the cumulative number of faults will be reset to zero, and the current sampled voltage of the faulty cell will be used as the current voltage.

9. A battery fault handling device, characterized in that, The device includes: The identification module is used to identify voltage anomalies based on the cell groups managed by the battery collector, and to identify adjacent faulty cell pairs that exhibit a high-low voltage characteristic. The identification module is also used to determine the fault type of the faulty battery cell pair based on the voltage parameters obtained from the equalization processing of the faulty battery cell pair and the preset fault judgment conditions; the fault type includes open circuit fault and moisture fault.

10. The apparatus according to claim 9, characterized in that, The device further includes a processing module, the processing module being used for: The faulty battery cell pairs are subjected to equalization processing to obtain voltage parameters; And / or, accumulate the number of faults for the faulty cell pairs determined to be the moisture fault, in order to identify suspected moisture faults or formal moisture faults.

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