A method, apparatus and system for monitoring the state of a battery

Abstract

The present application relates to the technical field of electric variable measurement, and in particular to a storage battery state monitoring method, device and system, comprising: obtaining the capacitance variation data and voltage variation data of each single battery in each battery group of the storage battery during discharging; calculating the abnormal state value and the equalization adjustment characteristic value of each single battery according to the capacitance variation data and voltage variation data; performing battery equalization processing in each battery group respectively based on the abnormal state value and the equalization adjustment characteristic value; and calculating the battery characteristic consistency between each battery group according to the equalization adjustment characteristic value, and performing battery equalization processing between each battery group based on the battery characteristic consistency. The present application can solve the technical problem that the traditional storage battery equalization strategy cannot ensure that each single battery in the storage battery realizes battery equalization, which seriously affects the charging and discharging efficiency of the storage battery and shortens the service life of the storage battery.

Description

Technical Field

[0001] This invention relates to the field of electrical variable measurement technology, specifically to a method, device, and system for monitoring the state of a storage battery. Background Technology

[0002] Storage batteries are commonly used electrical energy storage devices, widely used in electric vehicles, new energy vehicles, power tools, and laptops. Battery balancing is an important technology to ensure normal battery charging and discharging and to improve battery life. Therefore, in order to ensure the battery's condition, it is necessary to monitor the battery in real time and determine whether battery balancing adjustments are needed.

[0003] Currently, battery balancing strategies mainly include active balancing and passive balancing. Passive balancing suffers from low energy utilization and generates additional heat during the energy consumption process using battery modules, significantly increasing the risk of battery safety incidents. Therefore, active balancing is more widely used in battery regulation.

[0004] Active balancing uses a voltage difference of 50mV or 100mV between battery packs as the basis for its balancing strategy. However, due to differences in the manufacturing process of different battery packs, even at the same voltage, their charge and discharge states can exhibit significant differences. This results in insufficient precision in the activation of the balancing strategy module during active balancing, failing to ensure that each individual cell in the battery achieves balancing. This severely impacts the battery's charge and discharge efficiency and shortens its lifespan. Summary of the Invention

[0005] To address the technical problem that traditional battery balancing strategies cannot ensure battery balancing for each individual cell in a battery, which severely affects the battery's charging and discharging efficiency and shortens its lifespan, the present invention aims to provide a battery state monitoring method, device, and system. The specific technical solution adopted is as follows:

[0006] In a first aspect, the present invention provides a method for monitoring the state of a storage battery, the method comprising:

[0007] Acquire the capacity and voltage change data of each individual cell in each battery pack during the discharge process;

[0008] Based on the capacitance change data and the voltage change data, calculate the abnormal state value and balance adjustment characteristic value for each individual battery cell;

[0009] Based on the abnormal state value and the balance adjustment characteristic value, battery balancing processing is performed in each battery pack.

[0010] The battery characteristic consistency among the battery packs is calculated based on the balance adjustment feature value, and battery balancing is performed among the battery packs based on the battery characteristic consistency.

[0011] Optionally, the capacity change data includes at least the remaining capacity of the single cell at each discharge time, the first capacity of the single cell in the capacity-time relationship curve at each discharge time, and the second capacity of the single cell in the voltage-capacity relationship curve at each discharge time, and the voltage change data includes at least the voltage time-series change data of the single cell in the voltage-time relationship curve within a preset time period;

[0012] Based on the capacitance change data and the voltage change data, calculate the abnormal state value and balance adjustment characteristic value for each individual cell, including:

[0013] Calculate the first capacity difference between the first capacity and the remaining capacity for each of the individual cells, and the second capacity difference between the second capacity and the remaining capacity;

[0014] Based on the first capacity difference, the second capacity difference, and the total capacity of the individual battery, calculate the abnormal state value of each individual battery in each battery pack;

[0015] Calculate the remaining capacity percentage relative to the total capacity of the individual battery cells, and calculate the average slope of the voltage change of the individual battery cells within the preset time period based on the voltage time-series change data;

[0016] Based on the abnormal state value, the remaining capacity percentage, and the average slope of the voltage change, the balance adjustment characteristic value of each individual cell in each battery pack is calculated.

[0017] Optionally, based on the abnormal state value, the remaining capacity percentage, and the average slope of the voltage change, the balance adjustment characteristic value of each individual cell in each battery pack is calculated, including:

[0018] Based on the remaining capacity percentage and the average slope of voltage change, the battery characteristics of each individual cell in each battery pack are constructed;

[0019] Based on the battery characteristics of each individual cell in each battery pack, calculate the average battery characteristics of each battery pack, as well as the correlation coefficient between voltage change and capacitance change in each battery pack.

[0020] Calculate the average abnormal state value of the multiple abnormal state values ​​corresponding to the multiple individual cells in each battery pack;

[0021] Using the battery characteristics, the mean of the battery characteristics, the correlation coefficient, the abnormal state value, and the mean of the abnormal state, the balance adjustment characteristic value of each individual cell in each battery pack is calculated.

[0022] Optionally, based on the abnormal state value and the balance adjustment characteristic value, battery balancing processing is performed separately within each battery pack, including:

[0023] Each battery pack is sequentially identified as the current battery pack, and the first battery equalization process is repeatedly executed on the current battery pack based on the abnormal state value.

[0024] After determining that the first battery equalization process has reached the first preset iteration condition, the second battery equalization process is repeated on the current battery pack based on the equalization adjustment feature value until the second preset iteration condition is reached, and it is determined that the current battery pack has completed the internal battery equalization adjustment.

[0025] Optionally, the first battery equalization process is repeatedly executed on the current battery pack based on the abnormal state value, including:

[0026] Determine whether there is an abnormal single battery cell in the current battery pack whose abnormal state value is greater than a first preset threshold.

[0027] If it is determined that there is an abnormal single cell in the current battery pack, then the first single cell and the second single cell are identified in the current battery pack, and the first single cell is controlled to replenish the second single cell with electrical energy.

[0028] Repeat the first battery equalization process described above until a first preset iteration condition is met. The first preset iteration condition is that the abnormal state value corresponding to all individual cells in the current battery pack is less than the first preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

[0029] Optionally, based on the balance adjustment feature value, the second battery balancing process is repeated for the current battery pack, including:

[0030] Calculate the battery balance adjustment parameters of the current battery pack based on the balance adjustment feature value, and determine whether the battery balance adjustment parameters are greater than the second preset threshold.

[0031] If it is determined that the battery balance adjustment parameter is greater than the second preset threshold, then a third cell and a fourth cell are identified in the current battery pack, and the third cell is controlled to replenish the fourth cell with electrical energy.

[0032] Repeat the above second battery equalization process until it is determined that the second preset iteration condition is met. The second preset iteration condition is that the battery equalization adjustment parameter corresponding to the current battery pack is less than the second preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

[0033] Optionally, the battery balance adjustment parameters of the current battery pack are calculated based on the balance adjustment feature values, including:

[0034] Determine multiple equalization adjustment feature values ​​corresponding to multiple individual cells within the current battery pack;

[0035] Extract the maximum and minimum values ​​of the equilibrium adjustment features from the plurality of equilibrium adjustment feature values;

[0036] The difference between the maximum value and the minimum value of the balance adjustment feature is determined as the battery balance adjustment parameter of the current battery pack.

[0037] Optionally, the step of calculating the battery characteristic consistency among the battery packs based on the balance adjustment feature value, and performing battery balancing processing among the battery packs based on the battery characteristic consistency, includes:

[0038] Repeat the third battery equalization process until the third preset iteration condition is met. The third preset iteration condition is that the consistency of battery characteristics between any two battery packs is greater than the third preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

[0039] The third battery equalization process includes:

[0040] Based on the balance adjustment characteristic value of each individual cell in each battery pack, the average balance adjustment characteristic value of each battery pack is calculated.

[0041] Based on the average battery characteristics of each battery pack and the average value of the balance adjustment characteristic, the consistency of battery characteristics between any two battery packs is calculated.

[0042] When it is determined that the consistency of battery characteristics between any two battery packs is less than the third preset threshold, the first battery pack and the second battery pack are identified among the multiple battery packs corresponding to the storage battery, and the first battery pack is controlled to replenish the second battery pack with electrical energy.

[0043] Secondly, embodiments of the present invention provide a battery status monitoring device, comprising:

[0044] The acquisition module is used to acquire the capacity change data and voltage change data of each individual cell in each battery pack of the storage battery during the discharge process.

[0045] The calculation module is used to calculate the abnormal state value and balance adjustment characteristic value of each individual battery cell based on the capacitance change data and the voltage change data.

[0046] The first processing module is used to perform battery equalization processing within each battery pack based on the abnormal state value and the equalization adjustment feature value.

[0047] The second processing module is used to calculate the battery characteristic consistency between the battery packs based on the balance adjustment feature value, and to perform battery balancing processing between the battery packs based on the battery characteristic consistency.

[0048] Thirdly, embodiments of the present invention also provide a battery status monitoring system, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of any of the methods described above.

[0049] The present invention has the following beneficial effects: The technical solution provided by the present invention first obtains the capacity and voltage change data of each individual cell in each battery pack during the discharge process. Then, based on the capacity and voltage change data, the abnormal state value and balance adjustment characteristic value of each individual cell are calculated. Further, based on the abnormal state value and balance adjustment characteristic value, battery balancing is performed within each battery pack. Finally, the battery characteristic consistency between battery packs is calculated based on the balance adjustment characteristic value, and battery balancing is performed between battery packs based on the battery characteristic consistency. By obtaining the capacity and voltage change data of each individual cell in each battery pack during the discharge process, the present invention provides more comprehensive battery state information compared to the traditional method that only relies on voltage difference. Based on the capacity and voltage change data, battery balancing within and between battery packs is performed sequentially during the battery discharge process. Under the dual effect of intra-pack and inter-pack balancing, the individual differences of each individual cell can be fully considered, thereby ensuring that each individual cell in the battery can achieve battery balancing, further improving the charging and discharging efficiency of the battery and extending its service life.

[0050] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Other features and advantages of the invention will be described in detail in the following detailed description section. Attached Figure Description

[0051] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic flowchart of a battery status monitoring method provided in one embodiment of the present invention;

[0053] Figure 2 A schematic flowchart of a battery status monitoring method provided in another embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the structure of a battery status monitoring device provided in an embodiment of this application. Detailed Implementation

[0055] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a battery status monitoring method, device, and system proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0057] The following description, in conjunction with the accompanying drawings, details a specific solution for a battery status monitoring method, device, and system provided by the present invention.

[0058] Please see Figure 1 The diagram illustrates a method flowchart for monitoring the state of a storage battery according to an embodiment of the present invention. The method includes the following steps:

[0059] Step 110: Obtain the capacity change data and voltage change data of each individual cell in each battery pack during the discharge process.

[0060] During battery discharge, smaller capacity or higher internal resistance cells will reach the discharge cutoff threshold first. Continuing to discharge after reaching this threshold will result in over-discharge, affecting battery lifespan. Therefore, battery equalization cannot be determined solely by voltage difference.

[0061] In specific application scenarios, the batteries to be monitored may include multiple battery packs, each containing multiple individual cells. When monitoring the battery status, data on the capacity and voltage changes of the individual cells within the battery pack can be acquired. This data helps to accurately determine the battery status and provides a strong basis for subsequent battery balancing strategies. Specifically, the capacity change data should include at least the remaining capacity of the individual cell at each discharge moment. The first capacity of a single cell in the capacity-time relationship curve at each discharge moment. And the second capacity of a single cell in the voltage-capacity relationship curve at each discharge moment. The voltage variation data may include at least the voltage time-series variation data of individual cells in the voltage-time relationship curve within a preset time period.

[0062] Among them, the remaining capacity This refers to the actual remaining releaseable capacity of a battery at a given discharge moment. In practical applications, such as when an electric vehicle is in motion, it allows users to intuitively understand the remaining driving range the battery can support. The capacity-time curve is a theoretical curve plotted based on the discharge conditions of a single battery cell under standard test conditions. On this curve, each discharge moment corresponds to a theoretical capacity value, i.e., the first capacity. The voltage-capacity curve illustrates the intrinsic relationship between battery voltage and capacity. However, due to factors such as battery internal resistance, polarization effects, and aging, this relationship is not constant. At each discharge moment, based on the actual voltage of a single cell, the corresponding capacity, or second capacity, can be found on this curve. The data records the voltage time-series changes of individual cells in the voltage-time relationship curve within a preset time period. It shows how the voltage of an individual cell changes over time during a pre-defined period.

[0063] Step 120: Based on the capacity change data and voltage change data, calculate the abnormal state value and balance adjustment characteristic value of each individual cell.

[0064] The abnormal state value (b-value) is primarily calculated based on capacity change data, reflecting the abnormal state of a single battery cell. A larger b-value indicates a greater deviation between the actual and theoretical capacity, resulting in greater capacity consumption within the same timeframe. This suggests potential performance issues requiring additional energy from other batteries to maintain balance. Conversely, a smaller b-value indicates the battery cell is in a normal charging / discharging state. For example, if a single battery cell's b-value significantly exceeds a set threshold (e.g., 0.2%), it indicates a significant performance difference compared to other batteries, necessitating immediate equalization adjustments. The equalization adjustment characteristic value (c-value) is calculated by combining capacity and voltage change data, and it is used to assess the necessity of equalization adjustments for a single battery cell.

[0065] Step 130: Based on the abnormal state values ​​and the balance adjustment characteristic values, perform battery balancing processing within each battery pack.

[0066] In this embodiment of the disclosure, each battery pack undergoes two battery equalization processes sequentially. For the same battery pack, a battery equalization process is first performed based on abnormal state values, and then a second battery equalization process is performed based on balance adjustment feature values.

[0067] The abnormal state value (b-value) comprehensively reflects the deviation between the actual and theoretical capacitance of a single battery cell. It is derived by comparing the capacitance differences of a single battery cell under different calculation methods. When the b-value is greater than a set threshold (e.g., 0.2%), it indicates the presence of a single battery cell with abnormal discharge within the battery pack. These abnormal batteries may have rapid capacity decay or high internal resistance, resulting in discharge characteristics different from other batteries. When performing battery equalization within a battery pack based on the abnormal state value, a box plot anomaly detection model can be used to classify the single batteries in the battery pack into two categories (M1 and M2). The b-value of M1 cells (i.e., the first single battery cell) is relatively small, meaning its discharge is relatively normal and it can be used as an energy output source; the b-value of M2 cells (i.e., the second single battery cell) is relatively large, indicating abnormal discharge and requiring energy replenishment. This classification provides a basis for initial equalization within the battery pack. By controlling the first single battery cell to replenish energy to the second single battery cell, energy can flow from relatively normal batteries to abnormal batteries, initially balancing the charge of each single battery cell within the battery pack.

[0068] The equalization adjustment characteristic value (c value) further comprehensively considers factors such as battery voltage change, remaining capacity ratio, and differences from the average characteristics of the battery pack. Through complex calculations (including voltage change slope, correlation coefficient r, etc.), it more accurately measures the degree of difference between the individual battery and the overall state of the battery pack. When performing battery equalization processing within a battery pack based on the equalization adjustment characteristic value, the range Rc of the individual batteries in the battery pack with respect to the equalization adjustment characteristic value can be calculated. When Rc is greater than a set threshold (such as 0.1), it indicates that the discharge difference of each individual battery in the battery pack is large and further equalization is required. Then, the individual batteries can be anomaly detected based on the range Rc, and the individual batteries in the battery pack can be divided into two categories (M(1) and M(-1)). The M(1) category batteries (i.e., the third individual battery) have relatively better characteristics and can be supplied with energy to the M(-1) category batteries (i.e., the fourth individual battery) with abnormal discharge, further optimizing the equalization state within the battery pack.

[0069] Within the battery pack, the aforementioned balancing process is continuously performed based on the b-value and c-value. After each adjustment, the b-value and c-value are recalculated, and it is determined again whether balancing needs to continue, until the preset iteration condition for cycle termination is met. Through this continuous iterative optimization method, the individual cells within the battery pack are kept in a similar discharge state as much as possible, reducing the overall performance degradation of the battery pack caused by inconsistencies in individual cells, improving the charge and discharge efficiency of the battery pack, and extending the battery pack's lifespan.

[0070] Step 140: Calculate the battery characteristic consistency between each battery pack based on the balance adjustment characteristic value, and perform battery balancing processing between each battery pack based on the battery characteristic consistency.

[0071] In a battery system, multiple battery packs work together, and each pack contains multiple individual cells. Due to differences in manufacturing processes and operating environments, the overall performance of the individual cells within different battery packs varies, leading to differences in the overall discharge state of each pack. Calculating the consistency of battery characteristics between packs and performing equalization processing based on this is crucial for improving the performance of the entire battery system.

[0072] In this embodiment of the disclosure, to measure the consistency between battery packs, the battery characteristic consistency between each battery pack can be calculated based on the balance adjustment feature value. When the calculated battery characteristic consistency is greater than a preset threshold (e.g., 0.9), it indicates that the consistency between different battery packs is strong, and their states are relatively similar during the discharge process. In this case, no equalization processing is required between battery packs. However, when the battery characteristic consistency is less than the preset threshold (e.g., 0.9), it indicates that there are significant differences between battery packs, and equalization adjustment is required. When it is determined that equalization processing between battery packs is needed, the operation process is similar to the equalization processing within a battery pack based on the balance adjustment feature value c. That is, according to the relevant characteristics of each battery pack, the battery packs are divided into two categories, and energy is transferred from one category to the other category to balance the differences in charge between different battery packs.

[0073] This method allows the battery packs to work more coordinatedly during discharge, preventing over-discharge or overcharging of some packs from affecting the performance and lifespan of the entire battery system. For example, in an energy storage system composed of multiple battery packs, if some packs discharge too quickly, the equalization process can transfer energy from slower-discharging packs, ensuring a relatively consistent discharge rate across all packs and improving the stability and reliability of the energy storage system.

[0074] In summary, the battery state monitoring method provided by this invention first acquires the capacity and voltage change data of each individual cell within each battery pack during the discharge process. Then, based on the capacity and voltage change data, it calculates the abnormal state value and balance adjustment characteristic value of each individual cell. Further, based on the abnormal state value and balance adjustment characteristic value, it performs battery balancing within each battery pack. Finally, it calculates the battery characteristic consistency between battery packs based on the balance adjustment characteristic value, and performs battery balancing between battery packs based on this consistency. This invention, by acquiring the capacity and voltage change data of each individual cell within each battery pack during the discharge process, provides more comprehensive battery state information compared to traditional methods that rely solely on voltage differences. Based on the capacity and voltage change data, it performs battery balancing within and between battery packs sequentially during battery discharge. This dual action of intra-pack and inter-pack balancing fully considers the individual differences of each individual cell, ensuring that each individual cell in the battery achieves battery balancing, further improving the battery's charging and discharging efficiency and extending its service life.

[0075] based on Figure 1 The embodiments shown are refinements and extensions of the above embodiments. To fully illustrate the specific implementation process of the method in this embodiment, this embodiment provides the following: Figure 2 The specific method is shown. Figure 2 based on Figure 1 The example shown. Figure 2 As shown, the method includes the following steps:

[0076] Step 210: Obtain the capacity change data and voltage change data of each individual cell in each battery pack during the discharge process.

[0077] Among them, the capacity change data may include at least the remaining capacity of a single cell at each discharge moment. The first capacity of a single cell in the capacity-time relationship curve at each discharge moment. And the second capacity of a single cell in the voltage-capacity relationship curve at each discharge moment. The voltage variation data may include at least the voltage time-series variation data of individual cells in the voltage-time relationship curve within a preset time period.

[0078] Step 220: Based on the capacity change data and voltage change data, calculate the abnormal state value and balance adjustment characteristic value of each individual cell.

[0079] Accordingly, for embodiments of this disclosure, step 220, which calculates the abnormal state value and balance adjustment characteristic value of each individual cell based on the capacity change data and voltage change data, may include the following steps:

[0080] Step 220-1: Calculate the first capacity difference between the first capacity and the remaining capacity for each individual cell, and the second capacity difference between the second capacity and the remaining capacity.

[0081] The first capacity difference refers to the difference between the first capacity and the remaining capacity of each individual battery cell. The first capacity is the theoretical capacity value of the individual battery cell at each discharge moment on the capacity-time curve. The remaining capacity is the actual remaining releaseable charge of the individual battery cell within the current second, obtained by monitoring the discharge process of the individual battery cell using methods such as the ampere-hour integration method. The calculation process of the first capacity difference is expressed by the formula: ,in, Indicates the difference in first capacitance. Let Q represent the initial capacity and Q represent the remaining capacity. The difference in initial capacity reflects the deviation between the actual and theoretical discharge performance of the battery. Due to individual differences in the battery manufacturing process, as well as aging and performance degradation during use, actual discharge performance often differs from theoretical performance. If the absolute value of the initial capacity difference is large and negative, it indicates that the actual capacity consumed by the current individual battery is greater than the theoretical capacity that should be consumed at that moment, potentially indicating a problem of excessively rapid capacity decay; if it is positive, it indicates that the actual capacity consumed is less than the theoretical value. By analyzing the initial capacity difference, we can preliminarily determine the capacity change trend and health status of individual batteries, providing an important basis for determining whether subsequent battery equalization is necessary.

[0082] The second capacity difference is the difference between the second capacity and the remaining capacity of each individual cell. The second capacity is determined by the voltage-capacity relationship curve of the individual cell, based on the capacity corresponding to the current voltage of the individual cell. The calculation process for the second capacity difference is also expressed by the formula: ,in, Indicates the difference in second capacitance. Let Q represent the second capacity and Q represent the remaining capacity. The difference in second capacity reflects the real-time state of the battery. The relationship between battery voltage and capacity is affected by various factors such as internal resistance, polarization effect, and aging. When the absolute value of the difference in second capacity is large, it means that the battery's voltage-capacity mapping relationship deviates from the theoretical model. For example, an increase in internal resistance may cause a change in voltage at the same capacity, or polarization effect, aging, or other reasons may alter the voltage-capacity curve. This difference helps to further understand the physical and chemical changes inside the battery, assists in determining whether the battery needs equalization, and how to perform more precise equalization operations.

[0083] Step 220-2: Based on the first capacity difference, the second capacity difference, and the total capacity of the individual cells, calculate the abnormal state value of each individual cell in each battery pack.

[0084] In a battery condition monitoring system, the abnormal state values ​​of individual cells are crucial for assessing battery health and implementing equalization strategies. Calculating abnormal state values ​​based on the first capacity difference, the second capacity difference, and the total capacity of the individual cells allows for a comprehensive assessment of the individual cell's condition using multi-dimensional information.

[0085] In this embodiment of the present disclosure, when calculating the abnormal state value of each individual cell within each battery pack, the first capacity difference, the second capacity difference, and the total capacity of the individual cells are first substituted into the first calculation formula to calculate the intermediate parameter of the capacity difference ratio. Further, the first capacity difference, the second capacity difference, and the capacity difference ratio are substituted into the second calculation formula to calculate the abnormal state value of the corresponding individual cell. The capacity difference ratio integrates the relationship between the first and second capacity differences and the total capacity, and is used to measure the proportion of the capacity difference in the total capacity under different calculation methods.

[0086] The formula characteristics of the first calculation formula are described as follows:

[0087] ;

[0088] In the formula, This indicates the percentage difference in capacity of a single battery cell. This indicates the first difference in capacity of the individual battery cells; This indicates the difference in the second capacity of the individual battery cell; This indicates the total electrical capacity of the single battery cell; This reflects the absolute value of the difference between the two different capacitance calculation methods, divided by the total capacitance. and multiply by This allows the differences to be standardized into a percentage value, facilitating comparisons between different batteries.

[0089] The formula characteristics of the second calculation formula are described as follows:

[0090] ;

[0091] In the formula, This indicates the abnormal state value of a single battery cell. This indicates the percentage difference in capacity of the individual battery cell; This indicates the first difference in capacity of the individual battery cells; This indicates the difference in the second capacity of the individual battery cell; This represents the overall fluctuation range of the difference between the two capacitance values. For normalization function, To normalize this fluctuation range so that it can be measured on a uniform scale. The larger the value, the greater the deviation between the actual capacitance and the theoretical capacitance, resulting in greater battery capacity consumption within the same time frame. This indicates that the individual cells deviate more from their normal state, necessitating balancing to maintain the consistency of performance among the cells in the battery pack; conversely, a smaller value indicates a greater deviation from the theoretical capacitance. The smaller the value, the greater the likelihood that the individual battery cell is in a normal charge / discharge state.

[0092] Step 220-3: Calculate the remaining capacity ratio of the remaining capacity to the total capacity of the individual cells, and calculate the average slope of the voltage change of the individual cells within a preset time period based on the voltage time series change data.

[0093] Remaining capacity percentage refers to the proportion of remaining capacity relative to the total capacity of a single battery cell. It can be expressed by the formula: .in, Q represents the percentage of remaining capacity of a single battery cell, where Q represents the remaining capacity of that single battery cell. This refers to the total electrical capacity of a single battery cell, which is the amount of electricity a battery can store under ideal conditions; it is an inherent property of the battery. The remaining capacity percentage visually represents the battery's current state of charge, such as... =0.5 indicates that the battery has half its charge remaining. It is significant in judging the battery status and balancing needs. For example, when comparing the discharge progress of different individual cells, the remaining capacity percentage can clearly show the degree of difference in the charge of each cell. If the remaining capacity percentage of different individual cells in the same battery pack varies greatly, balancing may be required to ensure that the discharge progress of each cell is consistent and to improve the overall performance of the battery pack.

[0094] The mean slope of voltage change is calculated based on voltage time-series change data. Specifically, multiple voltage time-series change data points for a single cell can be acquired within a preset time period (e.g., 1 second), with each voltage time-series change data point containing the voltage change. and the corresponding time difference Through formula The slope of the voltage change corresponding to the voltage time series data can be calculated. Then, the average of multiple voltage change slopes corresponding to multiple voltage time-series change data within a preset time period is used to obtain the mean voltage change slope (VK). This mean reflects the average rate of voltage change of a single cell within the preset time period. Under normal circumstances, the voltage change during battery discharge should be relatively stable, with a small mean voltage change slope and relatively uniform change. If the mean voltage change slope is large, it means that the voltage fluctuates drastically within that time period, which may indicate an abnormality in the battery, such as changes in internal resistance or unstable internal chemical reactions. This requires further analysis to determine whether battery equalization adjustments are necessary. However, since the rate of voltage change varies with the remaining charge of the battery (slow change at full charge, fast change at low charge), the mean voltage change slope needs to be combined with other indicators such as the remaining capacity percentage to comprehensively judge the battery status.

[0095] Step 220-4: Based on the abnormal state value, remaining capacity percentage and average voltage change slope, calculate the balance adjustment characteristic value of each individual cell in each battery pack.

[0096] Remaining capacity percentage The mean slope of voltage change, VK, reflects the state of a single cell from different perspectives. Remaining capacity percentage. This displays the proportion of the battery's current remaining charge to its total charge, reflecting the battery's charge level; the mean slope of voltage change, VK, reflects the average rate of voltage change over a preset time period, demonstrating the voltage stability during battery discharge. Combining these two parameters allows us to construct the battery characteristics of each individual cell within each battery pack. Such battery feature vectors can comprehensively describe the voltage and capacity status of a single battery cell, providing basic data for subsequent analysis. Among these, the remaining capacity percentage is utilized... Battery characteristics are constructed using the mean slope of voltage change, VK. In this case, any conventional feature construction method can be used, which will not be elaborated here. Furthermore, it can be based on the battery characteristics of each individual cell within each battery pack. Calculate the average battery characteristic of the battery pack. This result is obtained by averaging the battery characteristics of all individual cells within the battery pack, representing the average characteristic level of the battery pack. Furthermore, the correlation coefficient *r* between voltage and capacitance changes within each battery pack can be calculated based on the battery characteristics of each individual cell. This coefficient reflects the degree of correlation between voltage and capacitance changes during the discharge process. If the absolute value of *r* is close to 1, it indicates a strong linear relationship between voltage and capacitance changes; if *r* is close to 0, it indicates a weaker relationship. By analyzing the correlation coefficient, the stability and consistency of the battery pack's discharge process can be determined. For example, if the *r* value of a battery pack is small (negative correlation), it means that the correlation between voltage and capacitance changes is not very strong during the discharge of that battery pack, and some individual cells may have abnormal states, requiring further attention. Furthermore, multiple abnormal state values ​​corresponding to multiple individual cells within each battery pack can be calculated. Mean of abnormal states Abnormal state values It is calculated based on the first capacity difference, the second capacity difference, etc., reflecting the degree of deviation of a single cell from its normal state. The average value of the abnormal state is calculated. This allows us to understand the average level of abnormal conditions in individual cells within the battery pack and assess the overall health of the battery pack. If A large value indicates that the individual cells within the battery pack deviate significantly from their normal state, suggesting a high likelihood of requiring balancing treatment. Finally, the battery characteristics can be... Battery characteristic mean Correlation coefficient r, outlier values and the mean of abnormal states Substituting into the third calculation formula, the balance adjustment characteristic value of each individual cell in each battery pack is calculated.

[0097] The formula characteristics of the third calculation formula are described as follows:

[0098] ;

[0099] In the formula, This represents the balance adjustment characteristic value of a single cell. This indicates the abnormal state value of the individual battery cell; This indicates multiple abnormal state values ​​corresponding to multiple individual cells within the battery pack containing the given individual cell. The average of abnormal states; Calculate the symbol for the vector norm; This indicates the degree of difference between the abnormal state value of the individual battery and the average abnormal state value of the battery pack. The greater the difference, the more obvious the difference between the abnormal state of the individual battery and other batteries in the battery pack, and the more necessary it is to perform balancing adjustments. This is the correlation coefficient between voltage and capacitance changes within the battery pack containing the individual cell. For the correlation coefficient Perform normalization processing; This describes the battery characteristics of the single cell; This represents the average value of the battery characteristics corresponding to multiple individual cells within the battery pack containing the given individual cell. This reflects the difference between the characteristics of the individual cell and the average characteristics of the battery pack, highlighting the unique characteristics of the individual cell within the battery pack. This value represents the difference between the characteristics of a single cell and the characteristics of an ideal cell. The smaller the value, the closer the single cell is to the ideal state, and the less necessary it is to balance and adjust.

[0100] Accordingly, for embodiments of this disclosure, the steps may include: constructing battery characteristics for each individual cell in each battery pack based on the remaining capacity percentage and the average slope of voltage change; calculating the average battery characteristic of each battery pack and the correlation coefficient between voltage change and capacitance change within each battery pack based on the battery characteristics of each individual cell in each battery pack; calculating the average abnormal state value of multiple abnormal state values ​​corresponding to multiple individual cells in each battery pack; and calculating the balance adjustment characteristic value of each individual cell in each battery pack using the battery characteristics, the average battery characteristic, the correlation coefficient, the abnormal state value, and the average abnormal state.

[0101] Step 230: Identify each battery pack as the current battery pack in sequence, and repeat the first battery equalization process for the current battery pack based on the abnormal state value.

[0102] For embodiments of this disclosure, the step 230 of repeatedly performing the first battery equalization process on the current battery pack based on the abnormal state value may include the following steps:

[0103] Step 230-1: Determine whether there are any abnormal individual cells in the current battery pack whose corresponding abnormal state value is greater than the first preset threshold.

[0104] The first preset threshold can be set according to the actual application scenario, such as 0.2.

[0105] Step 230-2: If it is determined that there is an abnormal single cell in the current battery pack, then identify the first single cell and the second single cell in the current battery pack, and control the first single cell to replenish the second single cell with power.

[0106] In this embodiment of the disclosure, after determining that an abnormal individual cell exists within the battery pack, it is necessary to identify a suitable first and second individual cell. Generally, a box plot anomaly detection model can be used to analyze the individual cells within the battery pack. The abnormal state values ​​of the battery pack are then... The input is fed into the box plot anomaly detection model, and the output is a set of anomalous individual cells located outside the box plot. Based on whether the data is located above or below the box plot, anomalous cells are divided into two categories (M1 and M2). Cells in the lower M1 category are considered anomalous. The size is slightly smaller; this type of battery is relatively normal as the first individual cell. The M2 type battery above indicates... Batteries with excessively large charge levels exhibit abnormal discharge and are designated as the second individual cell. Once the first and second individual cells are identified, measures need to be taken to allow the first cell to replenish the energy of the second. This is a crucial step in achieving battery pack balancing. In practice, a Battery Management System (BMS) is typically used to control circuit switches, allowing energy to flow from the first to the second individual cell. For example, inductors, capacitors, or DC-DC converters can be used to transfer energy from the first cell to the second, replenishing the second cell's charge and reducing the charge difference between individual cells within the pack. This improves the overall performance of the battery pack and prevents reduced charging / discharging efficiency and shortened lifespan caused by excessively large differences in charge levels between individual cells.

[0107] Step 230-3: Repeat the above first battery equalization process until the first preset iteration condition is met. The first preset iteration condition is that the abnormal state value of all individual cells in the current battery pack is less than the first preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

[0108] The maximum balancing duration can be set according to the actual application scenario, such as 5 minutes.

[0109] Step 240: After determining that the first battery equalization process has reached the first preset iteration condition, the second battery equalization process is repeated on the current battery pack based on the equalization adjustment feature value until the second preset iteration condition is reached, and the internal battery equalization adjustment of the current battery pack is determined to be completed.

[0110] In this embodiment of the disclosure, step 240, which involves repeatedly performing the second battery equalization process on the current battery pack based on the equalization adjustment feature value, may include the following steps:

[0111] Step 240-1: Calculate the battery balance adjustment parameters of the current battery pack based on the balance adjustment feature value, and determine whether the battery balance adjustment parameters are greater than the second preset threshold.

[0112] In the embodiments of this disclosure, when calculating the battery balance adjustment parameters of the current battery pack based on the balance adjustment characteristic values, multiple balance adjustment characteristic values ​​of multiple individual cells within the battery pack can be obtained. Find the maximum value among them. and minimum value These two values ​​represent two extreme cases regarding the equalization adjustment requirements of individual cells within the battery pack. The corresponding individual cell may have the greatest difference from the overall state of the battery pack and is the one that most needs to be balanced and adjusted. The corresponding individual cells show relatively small differences in state relative to the overall battery pack. "Equilibrium" here does not refer to actual energy transfer, but rather to understanding the range of state differences among individual cells within the battery pack by analyzing these two extreme values, providing a basis for determining subsequent adjustment strategies. For example, if... It's very big. The value is very small, indicating significant differences in the state of individual cells within the battery pack, requiring close monitoring and balancing. Further calculations can be performed. and The difference, i.e. This difference These are the battery balance adjustment parameters for the current battery pack. The higher the value, the greater the difference in actual discharge performance of individual cells within the battery pack, and the greater the necessity for balancing adjustments. For example, when... When the threshold is exceeded (e.g., 0.1), the individual cells in the battery pack need to be balanced. By distributing electrical energy to individual cells in different states, their states are made more consistent, thereby improving the overall performance of the battery pack, such as charging and discharging efficiency and lifespan.

[0113] Accordingly, the implementation steps may include: determining multiple balance adjustment feature values ​​corresponding to multiple individual cells in the current battery pack; extracting the maximum and minimum balance adjustment feature values ​​from the multiple balance adjustment feature values; and determining the difference between the maximum and minimum balance adjustment feature values ​​as the battery balance adjustment parameter of the current battery pack.

[0114] Step 240-2: If the battery balance adjustment parameter is determined to be greater than the second preset threshold, then the third and fourth individual cells are identified in the current battery pack, and the third individual cell is controlled to replenish the power of the fourth individual cell.

[0115] The second preset threshold can be set according to the actual application scenario, such as 0.1. When When the value exceeds this second preset threshold, it indicates a significant difference in the actual discharge status of the individual cells within the current battery pack. For example, if... =0.15, which is greater than the preset threshold of 0.1. This means that some individual cells in the battery pack are discharging too fast or too slow, and their state is significantly different from that of other individual cells. If no adjustment is made, it will affect the overall performance and lifespan of the battery pack. At this time, it is necessary to start battery balancing measures.

[0116] Once it is determined that balancing adjustment is needed, suitable third and fourth individual cells must be identified within the current battery pack. This is usually determined based on various characteristic values ​​of the individual cells calculated previously (such as abnormal state value b, balancing adjustment characteristic value c, etc.) and related markings. For example, after detecting anomalies in individual cells, the abnormal cells are divided into two categories, marked as M(1) and M(-1). Cells of category M(1) are relatively normal and can be used as the third individual cell, capable of replenishing energy for other cells; cells of category M(-1) are abnormally discharging and require energy replenishment, thus serving as the fourth individual cell. Through such classification and selection, the direction and object of energy transfer are clarified. After determining the third and fourth individual cells, the energy transfer can also be controlled by the Battery Management System (BMS). The BMS will operate relevant electronic components (such as switches, DC-DC converters, etc.) through specific circuits and control algorithms to allow the energy of the third individual cell to flow to the fourth individual cell. During this process, the BMS will monitor the battery's state parameters (such as voltage, current, etc.) in real time to ensure the safety and stability of the energy transfer process.

[0117] Step 240-3: Repeat the above second battery equalization process until the second preset iteration condition is met. The second preset iteration condition is that the battery equalization adjustment parameter corresponding to the current battery pack is less than the second preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

[0118] The maximum balancing duration can be set according to the actual application scenario, such as 5 minutes.

[0119] Step 250: Calculate the battery characteristic consistency between each battery pack based on the balance adjustment characteristic value, and perform battery balancing processing between each battery pack based on the battery characteristic consistency.

[0120] In this embodiment of the present disclosure, when calculating the battery characteristic consistency between each battery pack based on the balance adjustment feature value in step 250, and performing battery balancing processing between each battery pack based on the battery characteristic consistency, the third battery balancing process can be repeatedly executed until a third preset iteration condition is determined to be met. The third preset iteration condition is that the battery characteristic consistency between any two battery packs is greater than a third preset threshold, or the cumulative battery balancing time reaches the maximum balancing time. The third preset threshold can be set according to the actual application scenario, such as 0.9; the maximum balancing time can be set according to the actual application scenario, such as 5 minutes.

[0121] The third battery equalization process may include the following steps:

[0122] Step 250-1: Calculate the average balance adjustment characteristic value of each battery pack based on the balance adjustment characteristic value of each individual cell in each battery pack.

[0123] A battery pack contains multiple individual cells, each with its own equalization adjustment characteristic value. Calculate the mean value of the balance adjustment characteristic of the battery pack. This involves adjusting the balance characteristic value of all individual cells within the group. The values ​​are then aggregated and averaged. The mean of the balance adjustment characteristic value represents the overall balance of the battery pack. If the mean of the balance adjustment characteristic value of a battery pack is small, it indicates that the state of each individual cell in the pack is relatively consistent, and the overall balance is good; conversely, if the mean is large, it means that there are large differences between the individual cells in the pack, the balance of the pack is poor, and it needs to be closely monitored and appropriate balancing measures may be taken to improve the performance of the battery pack.

[0124] Step 250-2: Based on the average battery characteristics and the average value of the balance adjustment characteristics of each battery pack, calculate the consistency of battery characteristics between any two battery packs.

[0125] In this embodiment of the disclosure, the average battery characteristics and the average balance adjustment characteristic values ​​corresponding to any two battery packs can be obtained respectively. Then, the average battery characteristics and the average balance adjustment characteristic values ​​of the two battery packs can be substituted into the fourth calculation formula to calculate the battery characteristic consistency between the two battery packs.

[0126] The formula characteristics of the fourth calculation formula are described as follows:

[0127] ;

[0128] In the formula, This indicates the consistency of battery characteristics between the i-th and j-th battery packs in the storage battery; This is a normalization function used to map calculation results to a specific interval for easier comparison. Let be the average characteristic of the i-th battery pack; The mean value of the balanced adjustment feature value for the i-th battery pack; Let be the average characteristic of the j-th battery pack; The mean value of the balanced characteristic value is adjusted for the j-th battery pack. The cosine similarity of the average feature vectors of two battery packs is used to measure the degree of directional similarity between them in the feature space. The closer the cosine value is to 1, the more similar the two battery packs are in terms of voltage change and state of charge. This represents the difference in the mean of the balance adjustment characteristic values ​​between two battery packs. The smaller this value, the smaller the difference in balance between the two battery packs. Battery characteristic consistency. A higher value indicates a more similar discharge state among different battery packs, resulting in stronger consistency. This allows for better synchronization during collaborative operation, reducing system performance degradation caused by differences in battery pack characteristics. For example, in the battery system of an electric vehicle, high consistency among battery packs allows for more even energy distribution during charging and discharging, preventing overcharging and over-discharging of some packs, thus improving the overall efficiency and safety of the battery system and extending battery life. Conversely, if... A small value indicates significant differences between battery packs, requiring appropriate balancing measures to improve consistency and ensure stable system operation. It should be noted that, to ensure meaningful calculation results, this embodiment of the invention adds a parameter adjustment factor greater than 0 to the denominator when performing fractional operations, preventing the denominator from being zero. The value of the parameter adjustment factor is set by the implementer according to the actual situation; this application does not impose any special restrictions.

[0129] Step 250-3: When it is determined that the consistency of battery characteristics between any two battery groups is less than the third preset threshold, the first battery group and the second battery group are determined among the multiple battery groups corresponding to the storage battery, and the first battery group is controlled to replenish the second battery group with power.

[0130] Once it is determined that the battery characteristic consistency is less than a third preset threshold, it is necessary to determine the first and second battery packs among multiple battery packs. The specific determination method usually relies on the relevant characteristic values ​​and markings of the battery packs. Generally, battery packs in relatively good condition and with sufficient charge are selected as the first battery pack, while those in poor condition and requiring recharging are designated as the second battery pack. For example, when analyzing the average characteristics and average balance adjustment characteristic values ​​of each battery pack, those battery packs with smaller average balance adjustment characteristic values ​​and average battery characteristics closer to the ideal state may be designated as the first battery pack; conversely, battery packs with larger average values ​​and deviating from the ideal state may become the second battery pack.

[0131] Once the first and second battery packs are determined, the next step is to control the flow of power from the first pack to the second. This process can also be executed by a Battery Management System (BMS). The BMS uses specific circuits and control strategies to operate relevant electronic components (such as switches and power converters) to ensure a safe and stable transfer of power from the first to the second pack. During the power replenishment process, the BMS monitors parameters such as voltage, current, and temperature of the battery packs in real time to ensure that the replenishment process does not damage the batteries. For example, if the voltage of the second pack is detected to be low, the BMS will adjust the circuitry to allow the first pack to charge the second pack with an appropriate current until the state difference between the two packs is reduced and the consistency of battery characteristics is improved to a reasonable range. This optimizes the performance of the entire battery system, extends battery life, and ensures stable system operation.

[0132] In summary, the technical solution in this application first obtains the capacity and voltage change data of each individual cell within each battery pack during the discharge process. Then, based on the capacity and voltage change data, it calculates the abnormal state value and balance adjustment characteristic value of each individual cell. Further, based on the abnormal state value and balance adjustment characteristic value, it performs battery balancing processing within each battery pack. Finally, it calculates the battery characteristic consistency between battery packs based on the balance adjustment characteristic value, and performs battery balancing processing between battery packs based on this consistency. This invention, by obtaining the capacity and voltage change data of each individual cell within each battery pack during the discharge process, provides more comprehensive battery state information compared to traditional methods that rely solely on voltage differences. Based on the capacity and voltage change data, it performs battery balancing within and between battery packs sequentially during battery discharge. This dual action of intra-pack and inter-pack balancing fully considers the individual differences of each individual cell, ensuring that each individual cell in the battery achieves battery balancing, further improving the battery's charging and discharging efficiency and extending its service life.

[0133] Based on the above Figure 1 , 2 A detailed description of the provided battery status monitoring method, such as Figure 3 As shown, Figure 3 This is a schematic diagram illustrating the structure of a battery status monitoring device according to an exemplary embodiment. Figure 3 As shown, the device includes:

[0134] The acquisition module 31 can be used to acquire the capacity change data and voltage change data of each individual cell in each battery pack of the storage battery during the discharge process;

[0135] The calculation module 32 can be used to calculate the abnormal state value and balance adjustment characteristic value of each individual cell based on the capacity change data and voltage change data.

[0136] The first processing module 33 can be used to perform battery equalization processing within each battery pack based on abnormal state values ​​and equalization adjustment feature values.

[0137] The second processing module 34 can be used to calculate the battery characteristic consistency between each battery pack based on the balance adjustment characteristic value, and to perform battery balancing processing between each battery pack based on the battery characteristic consistency.

[0138] In specific application scenarios, the capacity change data includes at least the remaining capacity of a single battery at each discharge moment, the first capacity of a single battery in the capacity-time relationship curve at each discharge moment, and the second capacity of a single battery in the voltage-capacity relationship curve at each discharge moment. The voltage change data includes at least the voltage time-series change data of a single battery in the voltage-time relationship curve within a preset time period. The calculation module 32 can be used to calculate the first capacity difference between the first capacity and the remaining capacity of each single battery, and the second capacity difference between the second capacity and the remaining capacity. Based on the first capacity difference, the second capacity difference, and the total capacity of the single battery, the abnormal state value of each single battery in each battery pack is calculated. The remaining capacity ratio of the remaining capacity relative to the total capacity of the single battery is calculated, and the average voltage change slope of the single battery within a preset time period is calculated based on the voltage time-series change data. Based on the abnormal state value, the remaining capacity ratio, and the average voltage change slope, the balance adjustment characteristic value of each single battery in each battery pack is calculated.

[0139] In specific application scenarios, when calculating the balance adjustment characteristic value of each individual cell in each battery pack based on abnormal state values, remaining capacity percentage, and average voltage change slope, the calculation module 32 can be used to construct the battery characteristics of each individual cell in each battery pack based on the remaining capacity percentage and average voltage change slope; calculate the average battery characteristic value of each battery pack based on the battery characteristics of each individual cell in each battery pack, as well as the correlation coefficient between voltage change and capacitance change in each battery pack; calculate the average abnormal state value of multiple abnormal state values ​​corresponding to multiple individual cells in each battery pack; and calculate the balance adjustment characteristic value of each individual cell in each battery pack using battery characteristics, average battery characteristic value, correlation coefficient, abnormal state value, and average abnormal state value.

[0140] In a specific application scenario, the first processing module 33 can be used to determine each battery pack as the current battery pack in sequence, and repeatedly execute the first battery equalization process on the current battery pack based on the abnormal state value; after determining that the first battery equalization process has reached the first preset iteration condition, the second battery equalization process is repeatedly executed on the current battery pack based on the equalization adjustment feature value until the second preset iteration condition is reached, and it is determined that the current battery pack has completed the internal battery equalization adjustment.

[0141] In specific application scenarios, when repeatedly executing the first battery balancing process on the current battery pack based on abnormal state values, the first processing module 33 can be used to determine whether there is an abnormal single cell in the current battery pack whose corresponding abnormal state value is greater than a first preset threshold; if it is determined that there is an abnormal single cell in the current battery pack, then the first single cell and the second single cell are identified in the current battery pack, and the first single cell is controlled to replenish the second single cell with electrical energy; the above first battery balancing process is repeated until it is determined that the first preset iteration condition is met. The first preset iteration condition is that the abnormal state values ​​corresponding to all single cells in the current battery pack are less than the first preset threshold, or the cumulative battery balancing time reaches the maximum balancing time.

[0142] In a specific application scenario, when the second battery balancing process is repeatedly executed on the current battery pack based on the balancing adjustment feature value, the first processing module 33 can be used to calculate the battery balancing adjustment parameter of the current battery pack based on the balancing adjustment feature value, and determine whether the battery balancing adjustment parameter is greater than the second preset threshold. If the battery balancing adjustment parameter is greater than the second preset threshold, the third and fourth individual cells are determined in the current battery pack, and the third individual cell is controlled to replenish the power of the fourth individual cell. The above second battery balancing process is repeated until the second preset iteration condition is met. The second preset iteration condition is that the battery balancing adjustment parameter corresponding to the current battery pack is less than the second preset threshold, or the cumulative battery balancing time reaches the maximum balancing time.

[0143] In specific application scenarios, when calculating the battery balance adjustment parameters of the current battery pack based on the balance adjustment feature values, the first processing module 33 can be used to determine multiple balance adjustment feature values ​​corresponding to multiple individual cells in the current battery pack; extract the maximum and minimum balance adjustment feature values ​​from the multiple balance adjustment feature values; and determine the difference between the maximum and minimum balance adjustment feature values ​​as the battery balance adjustment parameters of the current battery pack.

[0144] In specific application scenarios, the second processing module 34 can be used to repeatedly execute the third battery balancing process until a third preset iteration condition is met. The third preset iteration condition is that the battery characteristic consistency between any two battery groups is greater than a third preset threshold, or the cumulative battery balancing time reaches the maximum balancing time. The third battery balancing process includes: calculating the average balance adjustment characteristic value of each battery group based on the balance adjustment characteristic value of each individual cell in each battery group; calculating the battery characteristic consistency between any two battery groups based on the average battery characteristic and the average balance adjustment characteristic value of each battery group; when it is determined that the battery characteristic consistency between any two battery groups is less than the third preset threshold, determining the first battery group and the second battery group among the multiple battery groups corresponding to the battery, and controlling the first battery group to replenish the second battery group with power.

[0145] Regarding the device in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0146] Based on the same inventive concept as the above method, this embodiment of the invention also provides a battery status monitoring system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any of the above-described battery status monitoring methods.

[0147] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0148] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0149] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for monitoring the state of a storage battery, characterized in that, The method includes: Acquire the capacity and voltage change data of each individual cell in each battery pack during the discharge process; Based on the capacitance change data and the voltage change data, calculate the abnormal state value and balance adjustment characteristic value for each individual battery cell; Based on the abnormal state value and the balance adjustment characteristic value, battery balancing processing is performed in each battery pack. The battery characteristic consistency between the battery packs is calculated based on the balance adjustment characteristic value, and battery balancing processing is performed between the battery packs based on the battery characteristic consistency. The capacity change data includes at least the remaining capacity of the single battery at each discharge time, the first capacity of the single battery in the capacity-time relationship curve at each discharge time, and the second capacity of the single battery in the voltage-capacity relationship curve at each discharge time. The voltage change data includes at least the voltage time-series change data of the single battery in the voltage-time relationship curve within a preset time period. Based on the capacitance change data and the voltage change data, calculate the abnormal state value and balance adjustment characteristic value for each individual cell, including: Calculate the first capacity difference between the first capacity and the remaining capacity for each of the individual cells, and the second capacity difference between the second capacity and the remaining capacity; Based on the first capacity difference, the second capacity difference, and the total capacity of the individual battery, calculate the abnormal state value of each individual battery in each battery pack; Calculate the remaining capacity percentage relative to the total capacity of the individual battery cells, and calculate the average slope of the voltage change of the individual battery cells within the preset time period based on the voltage time-series change data; Based on the abnormal state value, the remaining capacity percentage, and the average slope of the voltage change, the balance adjustment characteristic value of each individual cell in each battery pack is calculated.

2. The battery status monitoring method according to claim 1, characterized in that, Based on the abnormal state value, the remaining capacity percentage, and the average voltage change slope, calculate the balance adjustment characteristic value of each individual cell in each battery pack, including: Based on the remaining capacity percentage and the average slope of voltage change, the battery characteristics of each individual cell in each battery pack are constructed; Based on the battery characteristics of each individual cell in each battery pack, calculate the average battery characteristics of each battery pack, as well as the correlation coefficient between voltage change and capacitance change in each battery pack. Calculate the average abnormal state value of the multiple abnormal state values ​​corresponding to the multiple individual cells in each battery pack; Using the battery characteristics, the mean of the battery characteristics, the correlation coefficient, the abnormal state value, and the mean of the abnormal state, the balance adjustment characteristic value of each individual cell in each battery pack is calculated.

3. The battery status monitoring method according to claim 1, characterized in that, Based on the abnormal state value and the balance adjustment characteristic value, battery balancing processing is performed within each battery pack, including: Each battery pack is sequentially identified as the current battery pack, and the first battery equalization process is repeatedly executed on the current battery pack based on the abnormal state value. After determining that the first battery equalization process has reached the first preset iteration condition, the second battery equalization process is repeated on the current battery pack based on the equalization adjustment feature value until the second preset iteration condition is reached, and it is determined that the current battery pack has completed the internal battery equalization adjustment.

4. The battery status monitoring method according to claim 3, characterized in that, Based on the abnormal state value, the first battery equalization process is repeatedly executed on the current battery pack, including: Determine whether there is an abnormal single battery cell in the current battery pack whose abnormal state value is greater than a first preset threshold. If it is determined that there is an abnormal single cell in the current battery pack, then the first single cell and the second single cell are identified in the current battery pack, and the first single cell is controlled to replenish the second single cell with electrical energy. Repeat the first battery equalization process described above until a first preset iteration condition is met. The first preset iteration condition is that the abnormal state value corresponding to all individual cells in the current battery pack is less than the first preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

5. The battery status monitoring method according to claim 3, characterized in that, Based on the balance adjustment feature value, the second battery equalization process is repeatedly executed on the current battery pack, including: Calculate the battery balance adjustment parameters of the current battery pack based on the balance adjustment feature value, and determine whether the battery balance adjustment parameters are greater than the second preset threshold. If it is determined that the battery balance adjustment parameter is greater than the second preset threshold, then a third cell and a fourth cell are identified in the current battery pack, and the third cell is controlled to replenish the fourth cell with electrical energy. Repeat the above second battery equalization process until it is determined that the second preset iteration condition is met. The second preset iteration condition is that the battery equalization adjustment parameter corresponding to the current battery pack is less than the second preset threshold, or the cumulative battery equalization time reaches the maximum equalization time.

6. The battery status monitoring method according to claim 5, characterized in that, Calculating the battery balance adjustment parameters of the current battery pack based on the balance adjustment feature value includes: Determine multiple equalization adjustment feature values ​​corresponding to multiple individual cells within the current battery pack; Extract the maximum and minimum values ​​of the equilibrium adjustment feature from the plurality of equilibrium adjustment feature values; The difference between the maximum value and the minimum value of the balance adjustment feature is determined as the battery balance adjustment parameter of the current battery pack.

7. The battery status monitoring method according to claim 2, characterized in that, The step of calculating the battery characteristic consistency among the battery packs based on the balance adjustment feature value, and performing battery balancing processing among the battery packs based on the battery characteristic consistency, includes: Repeat the third battery equalization process until the third preset iteration condition is met. The third preset iteration condition is that the consistency of battery characteristics between any two battery packs is greater than the third preset threshold, or the cumulative battery equalization time reaches the maximum equalization time. The third battery equalization process includes: Based on the balance adjustment characteristic value of each individual cell in each battery pack, the average balance adjustment characteristic value of each battery pack is calculated. Based on the average battery characteristics of each battery pack and the average value of the balance adjustment characteristic, the consistency of battery characteristics between any two battery packs is calculated. When it is determined that the consistency of battery characteristics between any two battery packs is less than the third preset threshold, the first battery pack and the second battery pack are identified among the multiple battery packs corresponding to the storage battery, and the first battery pack is controlled to replenish the second battery pack with electrical energy.

8. A battery status monitoring device, characterized in that, include: The acquisition module is used to acquire the capacity change data and voltage change data of each individual cell in each battery pack of the storage battery during the discharge process. The calculation module is used to calculate the abnormal state value and balance adjustment characteristic value of each individual battery cell based on the capacitance change data and the voltage change data. The capacity change data includes at least the remaining capacity of the single battery at each discharge time, the first capacity of the single battery in the capacity-time relationship curve at each discharge time, and the second capacity of the single battery in the voltage-capacity relationship curve at each discharge time. The voltage change data includes at least the voltage time-series change data of the single battery in the voltage-time relationship curve within a preset time period. Based on the capacitance change data and the voltage change data, calculate the abnormal state value and balance adjustment characteristic value for each individual cell, including: Calculate the first capacity difference between the first capacity and the remaining capacity for each of the individual cells, and the second capacity difference between the second capacity and the remaining capacity; Based on the first capacity difference, the second capacity difference, and the total capacity of the individual battery, calculate the abnormal state value of each individual battery in each battery pack; Calculate the remaining capacity percentage relative to the total capacity of the individual battery cells, and calculate the average slope of the voltage change of the individual battery cells within the preset time period based on the voltage time-series change data; Based on the abnormal state value, the remaining capacity percentage, and the average slope of the voltage change, calculate the balance adjustment characteristic value of each individual cell in each battery pack; The first processing module is used to perform battery equalization processing within each battery pack based on the abnormal state value and the equalization adjustment feature value. The second processing module is used to calculate the battery characteristic consistency between the battery packs based on the balance adjustment feature value, and to perform battery balancing processing between the battery packs based on the battery characteristic consistency.

9. A battery status monitoring system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is executed by the processor, it implements the steps of a battery status monitoring method as described in any one of claims 1 to 7.

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