Battery pack cell voltage anomaly detection method, device, equipment and medium

Abstract

The application provides a battery pack cell voltage anomaly detection method, device, equipment and medium, obtains the cell voltage of each cell in the battery pack of a target vehicle at any target time to obtain a cell voltage data set; preprocesses the cell voltage in the cell voltage data set to obtain a processed cell voltage data set; maps the cell voltage in the processed cell voltage data set to a plurality of voltage intervals divided in advance to obtain the frequency of the cell voltage in each voltage interval; calculates the consistency index of the cell voltage of the battery pack at the target time based on the frequency of the cell voltage in the plurality of voltage intervals, wherein the consistency index is used to represent the uniformity of the distribution of the cell voltage of each cell in the battery pack; and determines whether to output a pre-warning prompt of accelerated degradation of the battery pack according to the consistency index at the target time. The application can solve the problem of high calculation delay and insufficient real-time performance.

Description

Technical Field

[0001] This application relates to the field of battery pack cell voltage anomaly detection technology, specifically to a battery pack cell voltage anomaly detection method, device, equipment, and medium. Background Technology

[0002] With the widespread adoption of new energy vehicles, cloud-based monitoring of cell voltage consistency within battery packs has become a key technology for assessing battery health and ensuring vehicle safety. A significant technological goal in this field is to achieve real-time, efficient monitoring of the status of massive amounts of vehicle batteries to promptly detect potential risks such as inconsistency degradation.

[0003] In related technologies, a differential voltage judgment method based on a fixed threshold is often used, relying on batch processing calculations of ordered historical voltage data within a time window to quantify consistency. Specifically, this method generally collects cell voltage sequences over a period of time, calculates the deviation of each cell voltage from the average voltage, and compares the deviation value with a preset static threshold to determine whether an anomaly exists. However, since this scheme is essentially based on batch processing calculations, its processing requires accumulating data within a certain time window, making it difficult to adapt to the out-of-order, streaming voltage data reported in real time by the vehicle; this results in high calculation latency, making true real-time monitoring impossible.

[0004] Therefore, when processing massive amounts of streaming voltage data generated by vehicles in the cloud, existing technologies are insufficient due to high computational latency and inadequate real-time performance, making it difficult to meet the need for continuous and real-time monitoring of the consistency of battery pack cells. Summary of the Invention

[0005] In view of this, this application aims to provide a method, apparatus, device and medium for detecting abnormal voltage of battery pack cells, so as to solve the problem that the technology is difficult to meet the need for continuous and real-time monitoring of the consistency of battery pack cells due to high computational delay and insufficient real-time performance.

[0006] The first aspect of this application provides a method for detecting abnormal cell voltage in a battery pack, including: Obtain the cell voltage of each cell in the battery pack of the target vehicle at any target time to obtain a set of cell voltage data; The cell voltages in the cell voltage data set are preprocessed to obtain the processed cell voltage data set. The cell voltages in the processed cell voltage data set are mapped to multiple pre-divided voltage intervals to obtain the frequency of cell voltages in each voltage interval. Based on the frequency of cell voltage within the multiple voltage ranges, the consistency index of cell voltage in the battery pack at the target time is calculated, wherein the consistency index is used to characterize the uniformity of cell voltage distribution in each cell of the battery pack. Based on the consistency index at the target time, determine whether to output a warning message indicating accelerated degradation of the battery pack.

[0007] In one possible implementation of this application, the step of determining whether to output a warning message indicating accelerated degradation of the battery pack based on the consistency index at the target time includes: determining the operating condition of the battery pack of the target vehicle; determining the rate of change of the cell voltage of the battery pack at the target time based on the operating condition of the battery pack and the consistency index at the target time; and determining whether to output a warning message indicating accelerated degradation of the battery pack based on the rate of change of the consistency index at the target time.

[0008] In one possible implementation of this application, determining the rate of change of the consistency index of the battery pack's cell voltage based on the battery pack's operating condition and the consistency index at the target time includes: if the battery pack is operating in a discharging condition, obtaining the consistency index of the battery pack's cell voltage calculated at the previous time; and calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the vehicle's travel distance from the previous time to the target time; if the battery pack is operating in a charging condition, obtaining the consistency index of the battery pack's cell voltage calculated at the previous time; and calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the charging change from the previous time to the target time.

[0009] In one possible implementation of this application, the battery pack operates in a discharge condition; correspondingly, the step of calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the vehicle travel distance from the previous time to the target time includes: calculating the difference between the consistency index at the target time and the consistency index at the previous time to obtain the change in the consistency index; and determining the ratio of the change in the consistency index to the vehicle travel distance as the rate of change of the consistency index.

[0010] In one possible implementation of this application, the battery pack operates in a charging state; correspondingly, the step of calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the change in charging from the previous time to the target time includes: calculating the difference between the consistency index at the target time and the consistency index at the previous time to obtain the change in the consistency index; and determining the ratio of the change in the consistency index to the change in charging as the rate of change of the consistency index.

[0011] In one possible implementation of this application, the step of determining whether to output a warning message indicating accelerated degradation of the battery pack based on the rate of change of the consistency index at the target time includes: acquiring the rate of change of the consistency index at the target time and the rate of change of the consistency index at multiple acquisition times prior to the target time, thereby obtaining multiple rates of change of the consistency index; performing curve fitting based on the rate of change of the multiple consistency indices to obtain a rate of change curve of the consistency index; calculating the first derivative value of the rate of change curve of the consistency index; if the first derivative value is greater than a preset derivative threshold, then determining to output a warning message indicating accelerated degradation of the battery pack; if the first derivative value is not greater than the preset derivative threshold, then determining not to output a warning message indicating accelerated degradation of the battery pack.

[0012] In one possible implementation of this application, the step of preprocessing the cell voltages in the cell voltage data set to obtain a processed cell voltage data set includes: determining whether there are null or invalid values ​​in the cell voltage data set; if there are null or invalid values, filling or deleting the null or invalid values; and normalizing each cell voltage according to a preset normalization algorithm to obtain the normalized cell voltages, which is the processed cell voltage data set.

[0013] A second aspect of this application provides a battery pack cell voltage anomaly detection device, comprising: The acquisition module is used to acquire the cell voltage of each cell in the battery pack of the target vehicle at any target time, and obtain a set of cell voltage data. The preprocessing module is used to preprocess the cell voltages in the cell voltage data set to obtain the processed cell voltage data set. The segmentation module is used to map the cell voltages in the processed cell voltage data set to multiple pre-divided voltage intervals to obtain the frequency of cell voltages in each voltage interval. The calculation module is used to calculate the consistency index of the cell voltage of the battery pack at a target time based on the frequency of the cell voltage in the multiple voltage ranges, wherein the consistency index is used to characterize the uniformity of the distribution of cell voltage of each cell in the battery pack. The early warning module is used to determine whether to output an early warning prompt indicating that the battery pack is experiencing accelerated degradation based on the consistency index at the target time.

[0014] A third aspect of this application provides a control device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to cause the at least one processor to perform a battery pack cell voltage anomaly detection method as described in the first aspect and possible implementations thereof.

[0015] The fourth aspect of this application provides a computer storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement a battery pack cell voltage anomaly detection method as described in the first aspect and possible implementations thereof.

[0016] The fifth aspect of this application provides a battery pack cell voltage anomaly detection system, comprising: a cloud and a vehicle, the vehicle having a battery pack; wherein the cloud is configured to perform a battery pack cell voltage anomaly detection method as described in the first aspect and possible implementations thereof for the vehicle's battery pack.

[0017] The sixth aspect of this application provides a computer program product, comprising: a computer program that, when executed by a processor, implements a battery pack cell voltage anomaly detection method as described in the first aspect and possible implementations of the first aspect.

[0018] The battery pack cell voltage anomaly detection method, apparatus, equipment, and medium provided in this application acquire the set of cell voltages of the battery pack at a single target time, preprocess them, and count the frequency of cell voltages falling within each voltage range. Finally, based on the distribution of cell voltage frequency within each voltage range, a consistency index is calculated to characterize the uniformity of cell voltage distribution in the battery pack. This scheme reconstructs consistency assessment from time series analysis to statistical analysis of the spatial distribution characteristics of cell voltage at a single time, making the assessment calculation rely only on a single frame of data arriving at a single time (the set of cell voltages at the target time). This achieves real-time, low-latency assessment of battery pack voltage consistency and improves the timeliness of monitoring battery pack cell consistency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this application, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram illustrating an application scenario for detecting abnormal cell voltage in a battery pack, as provided in an embodiment of this application.

[0021] Figure 2 A flowchart illustrating the battery pack cell voltage anomaly detection method provided in this application embodiment. Figure 1 .

[0022] Figure 3 A flowchart illustrating the battery pack cell voltage anomaly detection method provided in this application embodiment. Figure 2 .

[0023] Figure 4 This is a schematic diagram of the battery pack cell voltage anomaly detection device provided in an embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the hardware structure of the control device provided in an embodiment of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In the field of new energy vehicles, to achieve quantitative assessment of the voltage consistency of numerous cells within a battery pack, related technologies typically employ statistically based batch processing methods. Specifically, this approach collects cell voltage sequences over a period of time, calculates the deviation of each cell's voltage from the average voltage, and compares the deviation value with a preset static threshold to determine if any anomalies exist. However, when this approach is applied to cloud scenarios requiring real-time, high-concurrency streaming monitoring of massive vehicle battery packs, its performance is less than ideal. The reasons are as follows: In practical applications where vehicle-side data is streamed to the cloud in out-of-order, single-frame snapshot format, existing methods heavily rely on an ordered and regular voltage sequence matrix within a time window. The cloud system must cache the continuously arriving massive amounts of out-of-order data, perform global reordering and concatenation by vehicle and time sequence before initiating batch processing calculations. This process results in extremely high computational latency and enormous intermediate state storage overhead, making real-time monitoring difficult to achieve, and system resource consumption increases linearly with the monitoring scale.

[0027] To address the aforementioned technical problems, this application proposes a different technical approach. The inventive concept is as follows: By reconstructing the perspective of battery pack consistency assessment from statistical analysis of time series data to statistical analysis of the spatial cross-sectional data distribution of all cell voltage values ​​at a single moment, and designing corresponding quantitative indicators, the data dependency mode of the calculation is fundamentally improved. This effectively enhances the real-time performance of the calculation and reduces resource consumption without significantly sacrificing the accuracy and statistical significance of the assessment. It solves the problems of high latency and high resource consumption caused by the reliance on time series data in cloud-based streaming monitoring scenarios, and achieves the technical effect of continuous and real-time monitoring of battery pack cell voltage consistency.

[0028] Figure 1 This is a schematic diagram illustrating an application scenario for abnormal cell voltage detection in a battery pack, as provided in an embodiment of this application. (Reference) Figure 1 This scenario includes a cloud platform 101 and a target vehicle 102, which contains a battery pack. The target vehicle 102 includes an onboard terminal that collects information about each cell in the battery pack and uploads it to the cloud platform 101. The onboard terminal can be the vehicle's controller. The cloud platform 101 can be a single server or a cluster of servers. The cloud platform 101 receives information about each cell in the battery pack from the target vehicle 102 and outputs various risk warnings for the battery pack based on this information. It should be noted that the cloud platform 101 can send risk warnings to the target vehicle and other monitoring platforms. It is also important to understand that the target vehicle 102 is a new energy vehicle, which can be a pure electric vehicle or a hybrid electric vehicle, etc.

[0029] It should be noted that the cloud 101 mentioned above, also known as the cloud platform, is not a single machine, but refers to a collective term for a large-scale remote software and hardware cluster, deployed in a remote data center on the Internet, providing computing power, storage and other services to the outside world; according to the deployment form, it can be divided into three categories: public cloud, private cloud, and hybrid cloud / edge cloud.

[0030] Exemplary methods Figure 2 A flowchart illustrating the battery pack cell voltage anomaly detection method provided in this application embodiment. Figure 1 The execution entity in this embodiment can be... Figure 1 The cloud in the illustrated embodiment. (As shown) Figure 2 As shown, the method includes: S201: Obtain the cell voltage of each cell in the battery pack of the target vehicle at any target time, and obtain a set of cell voltage data.

[0031] In the embodiments of this application, a stream processing engine can be used to obtain the cell voltage of each cell in the battery pack at each time from the vehicle terminal of the target vehicle.

[0032] Specifically, the cell voltage at each moment can be extracted from the stream processing engine according to a preset time interval. Here, any target moment can be any moment among the various acquisition moments.

[0033] The stream processing engine can be Kafka, Flink, or Spark Streaming.

[0034] The set of cell voltage data for each cell in the battery pack at the target time t is recorded as follows: As a computational object, Let be the voltage of the i-th cell. This refers to the number of battery cells in the battery pack.

[0035] S202: Preprocess the cell voltages in the cell voltage data set to obtain the processed cell voltage data set.

[0036] In this application, "preprocessing" refers to any operation performed on raw voltage data aimed at improving data quality or adapting it to the requirements of subsequent calculations. Specifically, it may refer to a combination of one or more steps such as validity cleaning, normalization, filtering and denoising, and unit conversion.

[0037] In one embodiment of this application, the cell voltage in the cell voltage data set is preprocessed, specifically including: Determine whether there are null or invalid values ​​in the cell voltage data set; if there are null or invalid values, fill or delete them; normalize each cell voltage according to the preset normalization algorithm, and the normalized cell voltage is the processed cell voltage data set.

[0038] First, determine if there are any null values ​​or invalid values ​​that are significantly outside the physically reasonable range in the cell voltage dataset (e.g., voltage values ​​less than 0V or greater than 5V are generally invalid for a single lithium-ion cell). If null or invalid values ​​are found, they are either padded or deleted. For example, the average voltage of adjacent cells can be used for padding, or the invalid cell data can be ignored (in which case the total number of valid cells N in the battery pack will decrease accordingly).

[0039] Secondly, the voltage of each effective cell is normalized according to a preset normalization algorithm. A commonly used normalization algorithm is linear normalization, which maps the original voltage value to the range [0, 1]. The specific calculation formula is as follows: Converted to the range [0,1], where This represents the maximum cell voltage in set U. This represents the minimum cell voltage in set U, resulting in the processed cell voltage data set. .

[0040] It should be noted that normalization can be achieved in various ways. For example, it can include, but is not limited to, linear normalization as described above, scaling normalization based on the battery's nominal voltage, or normalization using historical voltage ranges. All these methods can transform the voltage value into a defined, finite numerical range for subsequent interval division and statistical analysis.

[0041] S203: Map the cell voltages in the processed cell voltage data set to multiple pre-divided voltage intervals to obtain the frequency of cell voltages in each voltage interval.

[0042] In the embodiments of this application, the number of pre-divided voltage ranges is... You can configure it as needed.

[0043] In one example, the normalized cell voltage is the processed cell voltage data mapped to the range [0, 1]. The normalized cell voltage range [0, 1] is then divided into... The intervals are represented as follows: Accordingly, statistical sets In the middle element common The set of frequencies of cell voltage in each interval , Indicates the first i Frequency of each voltage range.

[0044] In one example The value is 10.

[0045] S204: Based on the frequency of cell voltage in multiple voltage ranges, the consistency index of cell voltage in the battery pack at the target time is calculated, where the consistency index is used to characterize the uniformity of cell voltage distribution in each cell of the battery pack.

[0046] In one embodiment of this application, the frequency probability of each voltage range can be determined based on the frequency of cell voltages in multiple voltage ranges, thereby obtaining a set of cell voltage probability distributions for the battery pack.

[0047] Wherein, the set of cell voltage probability distributions p= In the formula for i Frequency probability of each voltage range.

[0048] Let q be the set of cell voltage probability distributions for an ideal battery pack. .

[0049] The difference index between the cell voltage probability distribution set p and the cell voltage probability distribution set q of the ideal battery pack is calculated. The difference index is used as a consistency index.

[0050] It should be noted that a higher consistency index indicates a worse uniformity in the distribution of cell voltage and a lower residual value of the battery pack.

[0051] S205: Based on the consistency index at the target time, determine whether to output a warning message indicating accelerated degradation of the battery pack.

[0052] In one embodiment of this application, if the consistency index at the target time exceeds the set index limit, it is determined that the battery pack is experiencing accelerated degradation, and an early warning prompt for accelerated degradation of the output battery pack is triggered.

[0053] In another embodiment of this application, the rate of change of the consistency index over time can also be determined, and whether the battery pack has experienced accelerated degradation can be determined based on the magnitude of the rate of change of the consistency index over time.

[0054] As described above, by acquiring the set of cell voltages of the battery pack at a single target time, preprocessing them, and counting the frequency of cell voltages falling within each voltage range, a consistency index is calculated based on the distribution of cell voltage frequency within each voltage range. This index characterizes the uniformity of cell voltage distribution in the battery pack. This scheme reconstructs consistency assessment from time series analysis to statistical analysis of the spatial distribution characteristics of cell voltage at a single time. This makes the assessment calculation rely only on a single frame of data arriving at a single time (the set of cell voltages at the target time), achieving real-time, low-latency assessment of battery pack voltage consistency and improving the timeliness of monitoring battery pack cell consistency.

[0055] Furthermore, statistical analysis based on the spatial distribution characteristics of cell voltage at a single moment, rather than relying on fixed thresholds, avoids misjudgments caused by different operating conditions, temperatures, and aging states, significantly improving the accuracy of battery pack degradation early warning. Additionally, the stream processing engine enables real-time, high-concurrency processing of massive data streams with extremely low computational latency.

[0056] Figure 3 A flowchart illustrating the battery pack cell voltage anomaly detection method provided in this application embodiment. Figure 2 . refer to Figure 3 This embodiment focuses on describing a specific implementation of step S205 above, in order to more reliably and accurately assess whether the battery pack is experiencing accelerated degradation, as detailed below: S251: Determine the operating condition of the target vehicle's battery pack.

[0057] In this embodiment, the battery pack operates under both discharge and charging conditions.

[0058] S252: Based on the battery pack's operating conditions and the consistency index at the target time, determine the rate of change of the battery pack's cell voltage consistency index at the target time.

[0059] In one embodiment of this application, if the battery pack is in a discharge condition, the consistency index of the battery pack cell voltage calculated at the previous moment is obtained; and the rate of change of the consistency index is calculated based on the consistency index at the target moment, the consistency index at the previous moment, and the vehicle travel distance from the previous moment to the target moment.

[0060] Specifically, the rate of change of the consistency index is calculated based on the consistency index at the target time, the consistency index at the previous time, and the vehicle travel distance from the previous time to the target time. This includes: calculating the difference between the consistency index at the target time and the consistency index at the previous time to obtain the change in the consistency index; and determining the ratio of the change in the consistency index to the vehicle travel distance as the rate of change of the consistency index.

[0061] The ratio of the change in the consistency index to the change in the vehicle's travel distance is defined as the rate of change of the consistency index, expressed by the following formula: In the formula, The rate of change of consistency index under discharge conditions; The difference between the consistency index at the target time and the consistency index at the previous time. The consistency index of the previous moment and the change in vehicle travel distance from the previous moment to the target moment are used.

[0062] In one embodiment of this application, if the battery pack is in a charging state, the consistency index of the battery pack cell voltage calculated at the previous moment is obtained; and the change rate of the consistency index is calculated based on the consistency index at the target moment, the consistency index at the previous moment, and the charging change from the previous moment to the target moment.

[0063] Specifically, the rate of change of the consistency index is calculated based on the consistency index at the target time, the consistency index at the previous time, and the change in charging from the previous time to the target time. This includes: calculating the difference between the consistency index at the target time and the consistency index at the previous time to obtain the change in the consistency index; and determining the ratio of the change in the consistency index to the change in charging as the rate of change of the consistency index.

[0064] The ratio of the change in consistency index to the change in charging is defined as the rate of change of consistency index, expressed by the following formula: In the formula, The rate of change of consistency indicators under charging conditions; The difference between the consistency index at the target time and the consistency index at the previous time. The consistency index of the previous time step and the change in charging from the previous time step to the target time step are used. This is the charging current value. This refers to the charging time.

[0065] S253: Based on the rate of change of the consistency index at the target time, determine whether to output a warning message indicating accelerated degradation of the battery pack.

[0066] In one embodiment of this application, step S253 may specifically include: Sa, obtain the rate of change of the consistency index at the target time, and the rate of change of the consistency index at multiple acquisition times before the target time, to obtain the rate of change of multiple consistency indices.

[0067] Sb. Based on the rate of change of multiple consistency indicators, curve fitting is performed to obtain the rate of change curve of the consistency indicators.

[0068] Sc, calculate the first derivative of the rate of change curve of the consistency index.

[0069] Sd. If the first derivative value is greater than the preset derivative threshold, then a warning message indicating accelerated degradation of the battery pack will be generated.

[0070] Se, if the first derivative value is not greater than the preset derivative threshold, then it is determined that no warning message of accelerated degradation of the battery pack will be output.

[0071] In the embodiments of this application, the number of consistency index change rates for multiple acquisition times prior to the target time can be set as needed. For example, selecting the change rates of consistency indices for five consecutive acquisition times prior to the target time yields a total of six consistency index change rates.

[0072] In the embodiments of this application, the curve fitting methods include, but are not limited to: least squares method, polynomial fitting (such as quadratic polynomial fitting) or sliding window linear regression, etc.

[0073] As can be seen from the above description, by determining the rate of change of the consistency index of the battery pack cell voltage at the target time based on the consistency index of the battery pack's operating conditions and the target time, the early warning processing of accelerated degradation of the battery pack can be realized at any time under any operating condition, thereby improving the all-time vehicle battery pack health monitoring.

[0074] Furthermore, by performing curve fitting and analysis on the rate of change of multiple consistency indicators, and calculating their first derivative (i.e., the accelerating trend of the rate of change), when it is found that the rate of change shows an accelerating upward trend and exceeds the preset derivative threshold, an early warning can be issued before the consistency indicators deteriorate significantly, thereby enabling early monitoring of the battery pack health status trend.

[0075] In another embodiment of this application, the normalized cell voltage is the processed cell voltage data mapped to the range [0, 1], and the normalized cell voltage range [0, 1] is divided into... The intervals are represented as follows: Accordingly, statistical sets In the middle element common The set of frequencies of cell voltage in each interval , Indicates the first i Frequency of each voltage range.

[0076] Accordingly, based on the frequency of cell voltage within multiple voltage ranges, the consistency index of cell voltage in the battery pack at the target time is calculated, and the calculation formula is as follows: In the formula, As a consistency indicator; This refers to the number of battery cells in the battery pack. For the first i The frequency of cell voltage within a voltage range; i The index of the voltage range is 1 to 1. , This represents the total number of voltage ranges.

[0077] The derivation principle of the above formula is explained as follows: It is known that the formula for calculating the difference index is... , For the two distributions used for comparison, This represents the statistical intervals [-∞, +∞]. In this example, the voltage values ​​of each cell are normalized and limited to the range [0, 1]. The accumulated statistical interval is defined as follows: p is a set The distribution represented, the probability of each statistical interval. q is the benchmark for comparison, i.e., uniform distribution and constant. . original formula = , in the formula It is a constant. ,so =1, , The final simplified form is .

[0078] As can be seen from the above description, the simplified formula for calculating the consistency index can further improve cloud processing efficiency and reduce computing costs.

[0079] Exemplary device Figure 4 This is a schematic diagram of the battery pack cell voltage anomaly detection device provided in an embodiment of this application. The battery pack cell voltage anomaly detection device includes: an acquisition module 401, a preprocessing module 402, a division module 403, a calculation module 404, and an early warning module 405.

[0080] The acquisition module 401 is used to acquire the cell voltage of each cell in the battery pack of the target vehicle at any target time, and obtain a set of cell voltage data.

[0081] The preprocessing module 402 is used to preprocess the cell voltages in the cell voltage data set to obtain the processed cell voltage data set.

[0082] The segmentation module 403 is used to map the cell voltage in the processed cell voltage data set to multiple pre-divided voltage intervals to obtain the frequency of cell voltage in each voltage interval. The calculation module 404 is used to calculate the consistency index of the cell voltage of the battery pack at a target time based on the frequency of the cell voltage in the multiple voltage ranges, wherein the consistency index is used to characterize the uniformity of the distribution of cell voltage of each cell in the battery pack.

[0083] The early warning module 405 is used to determine whether to output an early warning prompt indicating that the battery pack is experiencing accelerated degradation based on the consistency index at the target time.

[0084] In one possible implementation of this application, the step of determining whether to output a warning message indicating accelerated degradation of the battery pack based on the consistency index at the target time includes: determining the operating condition of the battery pack of the target vehicle; determining the rate of change of the cell voltage of the battery pack at the target time based on the operating condition of the battery pack and the consistency index at the target time; and determining whether to output a warning message indicating accelerated degradation of the battery pack based on the rate of change of the consistency index at the target time.

[0085] In one possible implementation of this application, determining the rate of change of the consistency index of the battery pack's cell voltage based on the battery pack's operating condition and the consistency index at the target time includes: if the battery pack is operating in a discharging condition, obtaining the consistency index of the battery pack's cell voltage calculated at the previous time; and calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the vehicle's travel distance from the previous time to the target time; if the battery pack is operating in a charging condition, obtaining the consistency index of the battery pack's cell voltage calculated at the previous time; and calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the charging change from the previous time to the target time.

[0086] In one possible implementation of this application, the battery pack operates in a discharge condition; correspondingly, the step of calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the vehicle travel distance from the previous time to the target time includes: calculating the difference between the consistency index at the target time and the consistency index at the previous time to obtain the change in the consistency index; and determining the ratio of the change in the consistency index to the vehicle travel distance as the rate of change of the consistency index.

[0087] In one possible implementation of this application, the battery pack operates in a charging state; correspondingly, the step of calculating the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the change in charging from the previous time to the target time includes: calculating the difference between the consistency index at the target time and the consistency index at the previous time to obtain the change in the consistency index; and determining the ratio of the change in the consistency index to the change in charging as the rate of change of the consistency index.

[0088] In one possible implementation of this application, the step of determining whether to output a warning message indicating accelerated degradation of the battery pack based on the rate of change of the consistency index at the target time includes: acquiring the rate of change of the consistency index at the target time and the rate of change of the consistency index at multiple acquisition times prior to the target time, thereby obtaining multiple rates of change of the consistency index; performing curve fitting based on the rate of change of the multiple consistency indices to obtain a rate of change curve of the consistency index; calculating the first derivative value of the rate of change curve of the consistency index; if the first derivative value is greater than a preset derivative threshold, then determining to output a warning message indicating accelerated degradation of the battery pack; if the first derivative value is not greater than the preset derivative threshold, then determining not to output a warning message indicating accelerated degradation of the battery pack.

[0089] In one possible implementation of this application, the step of preprocessing the cell voltages in the cell voltage data set to obtain a processed cell voltage data set includes: determining whether there are null or invalid values ​​in the cell voltage data set; if there are null or invalid values, filling or deleting the null or invalid values; and normalizing each cell voltage according to a preset normalization algorithm to obtain the normalized cell voltages, which is the processed cell voltage data set.

[0090] The apparatus provided in this application embodiment can be used to execute the technical solutions of the above method embodiments. Its implementation principle and technical effect are similar, and will not be repeated here.

[0091] Exemplary devices and systems Figure 5 This is a schematic diagram of the hardware structure of the control device provided in an embodiment of this application. Figure 5 As shown, the control device in this embodiment includes a processor 501 and a memory 502.

[0092] The memory 502 stores computer-executed instructions; the processor 501 executes the computer-executed instructions stored in the memory to implement the various steps performed by the control device in the above embodiments. For details, please refer to the relevant descriptions in the foregoing method embodiments.

[0093] Alternatively, the memory 502 can be either standalone or integrated with the processor 501.

[0094] When the memory 502 is set up independently, the control device also includes a bus 503 for connecting the memory 502 and the processor 501.

[0095] This application embodiment also provides a vehicle, which includes: a vehicle body, the vehicle body being equipped with an on-board terminal, the on-board terminal being connected to a cloud for communication, and the cloud being used to perform the above-mentioned battery pack cell voltage abnormality detection method for the vehicle.

[0096] This application embodiment also provides a battery pack cell voltage anomaly detection system, including: a cloud and a vehicle, the vehicle having a battery pack; wherein the cloud is used to perform the above-described battery pack cell voltage anomaly detection method for the vehicle's battery pack.

[0097] Exemplary media and products This application also provides a computer storage medium storing computer execution instructions. When the processor executes the computer execution instructions, the above-mentioned battery pack cell voltage abnormality detection method is implemented.

[0098] This application also provides a computer program product, including a computer program, which, when executed by a processor, implements the above-described method for detecting abnormal battery pack cell voltage.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0100] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to implement the solution of this embodiment according to actual needs.

[0101] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The unit composed of the above modules can be implemented in hardware or in the form of hardware plus software functional units.

[0102] The integrated modules described above, implemented as software functional modules, can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods of the various embodiments of this application.

[0103] It should be understood that the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly manifested as execution by a hardware processor, or execution by a combination of hardware and software modules within the processor.

[0104] The memory may include high-speed RAM, and may also include non-volatile storage (NVM), such as at least one disk storage device, and may also be a USB flash drive, external hard drive, read-only memory, disk or optical disc, etc.

[0105] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0106] The aforementioned storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0107] An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Alternatively, the storage medium can be an integral part of the processor. Both the processor and the storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and storage medium can exist as discrete components in a control device.

[0108] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for detecting abnormal cell voltage in a battery pack, characterized in that, Applied to the cloud, including: Obtain the cell voltage of each cell in the battery pack of the target vehicle at any target time to obtain a set of cell voltage data; The cell voltages in the cell voltage data set are preprocessed to obtain the processed cell voltage data set. The cell voltages in the processed cell voltage data set are mapped to multiple pre-divided voltage intervals to obtain the frequency of cell voltages in each voltage interval. Based on the frequency of cell voltage within the multiple voltage ranges, the consistency index of cell voltage in the battery pack at the target time is calculated, wherein the consistency index is used to characterize the uniformity of cell voltage distribution in each cell of the battery pack. Based on the consistency index at the target time, determine whether to output a warning message indicating accelerated degradation of the battery pack.

2. The method according to claim 1, characterized in that, The step of determining whether to output a warning message indicating accelerated degradation of the battery pack based on the consistency index at the target time includes: Determine the operating condition of the target vehicle's battery pack; Based on the operating conditions of the battery pack and the consistency index at the target time, determine the rate of change of the consistency index of the cell voltage of the battery pack at the target time. Based on the rate of change of the consistency index at the target time, determine whether to output a warning message indicating accelerated degradation of the battery pack.

3. The method according to claim 2, characterized in that, The determination of the rate of change of the consistency index of the cell voltage of the battery pack based on the operating conditions of the battery pack and the consistency index at the target time includes: If the battery pack is in a discharge condition, the consistency index of the battery pack cell voltage calculated at the previous moment is obtained; and the change rate of the consistency index is calculated based on the consistency index at the target moment, the consistency index at the previous moment, and the vehicle travel distance from the previous moment to the target moment. If the battery pack is in charging condition, the consistency index of the battery pack cell voltage calculated at the previous moment is obtained; and the change rate of the consistency index is calculated based on the consistency index at the target moment, the consistency index at the previous moment, and the charging change from the previous moment to the target moment.

4. The method according to claim 3, characterized in that, The battery pack operates under a discharge condition; correspondingly, the calculation of the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the vehicle travel distance from the previous time to the target time includes: The difference between the consistency index at the target time and the consistency index at the previous time is calculated to obtain the change in the consistency index. The ratio of the change in the consistency index to the change in the distance traveled by the vehicle is determined as the rate of change of the consistency index.

5. The method according to claim 3, characterized in that, The battery pack operates in a charging state; correspondingly, the calculation of the rate of change of the consistency index based on the consistency index at the target time, the consistency index at the previous time, and the charging change from the previous time to the target time includes: The difference between the consistency index at the target time and the consistency index at the previous time is calculated to obtain the change in the consistency index. The ratio of the change in the consistency index to the change in the charging amount is determined as the rate of change of the consistency index.

6. The method according to claim 2, characterized in that, The step of determining whether to output a warning message indicating accelerated degradation of the battery pack based on the rate of change of the consistency index at the target time includes: Obtain the rate of change of the consistency index at the target time, and the rate of change of the consistency index at multiple collection times prior to the target time, to obtain the rate of change of multiple consistency indices; Curve fitting is performed based on the rate of change of the multiple consistency indicators to obtain the rate of change curve of the consistency indicators; Calculate the first derivative of the rate of change curve of the consistency index; If the first derivative value is greater than a preset derivative threshold, then a warning message indicating accelerated degradation of the battery pack will be output. If the first derivative value is not greater than a preset derivative threshold, then it is determined that no warning message will be output indicating accelerated degradation of the battery pack.

7. The method according to any one of claims 1 to 6, characterized in that, The step of preprocessing the cell voltages in the cell voltage data set to obtain the processed cell voltage data set includes: Determine whether there are any null or invalid values ​​for the cell voltage in the cell voltage data set; If there are empty or invalid values, then the empty or invalid values ​​are filled in or deleted. The voltage of each cell is normalized according to a preset normalization algorithm, and the normalized cell voltage is the set of processed cell voltage data.

8. A battery pack cell voltage anomaly detection device, characterized in that, include: The acquisition module is used to acquire the cell voltage of each cell in the battery pack of the target vehicle at any target time, and obtain a set of cell voltage data. The preprocessing module is used to preprocess the cell voltages in the cell voltage data set to obtain the processed cell voltage data set. The segmentation module is used to map the cell voltages in the processed cell voltage data set to multiple pre-divided voltage intervals to obtain the frequency of cell voltages in each voltage interval. The calculation module is used to calculate the consistency index of the cell voltage of the battery pack at a target time based on the frequency of the cell voltage in the multiple voltage ranges, wherein the consistency index is used to characterize the uniformity of the distribution of cell voltage of each cell in the battery pack. The early warning module is used to determine whether to output an early warning prompt indicating that the battery pack is experiencing accelerated degradation based on the consistency index at the target time.

9. A control device, characterized in that, include: At least one processor; The device includes a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to cause the at least one processor to perform the battery pack cell voltage anomaly detection method according to any one of claims 1 to 7.

10. A battery pack cell voltage anomaly detection system, characterized in that, include: The cloud and the vehicle, wherein the vehicle has a battery pack; The cloud is used to perform the battery pack cell voltage anomaly detection method according to any one of claims 1 to 7 for the vehicle's battery pack.

11. A computer storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the battery pack cell voltage anomaly detection method as described in any one of claims 1 to 7.

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