Storage battery state monitoring method, device and system

Abstract

The invention relates to the technical field of electrical variable measurement, in particular to a storage battery state monitoring method, device and system, and the method comprises the steps: obtaining the capacitance change data and voltage change data of each single battery in each battery pack of a storage battery in a discharging process; according to the capacitance change data and the voltage change data, calculating an abnormal state value and a balance adjustment characteristic value of each single battery; based on the abnormal state value and the balance adjustment characteristic value, battery equalization processing is carried out in each battery pack; and calculating battery characteristic consistency among the battery packs according to the balance adjustment characteristic values, and performing battery equalization processing among the battery packs based on the battery characteristic consistency. The technical problems that the charging and discharging efficiency of the storage battery is seriously influenced and the service life of the storage battery is shortened due to the fact that a traditional storage battery equalization strategy cannot ensure that each single battery in the storage battery realizes battery equalization can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical variable measurement, and particularly to a method, device and system for monitoring the state of a storage battery. Background Art

[0002] A storage battery is a commonly used electrical energy storage device and is widely used in electric vehicles, new energy vehicles, electric tools, and laptops. Battery equalization is an important technology to ensure normal charging and discharging of the battery and extend the service life of the battery. Therefore, in order to ensure the battery state of the storage battery, it is necessary to monitor the storage battery in real time to determine whether equalization adjustment of the storage battery is required.

[0003] Currently, battery equalization strategies mainly include active equalization and passive equalization. Among them, the passive equalization has low energy utilization rate. During the process of consuming electrical energy by means of a module, additional heat will be generated, significantly increasing the risk of safety accidents of the storage battery. In view of this, active equalization has been more widely applied in the regulation of storage batteries.

[0004] Active equalization is based on whether the voltage difference of the battery pack exceeds 50 mV or 100 mV as the basis for the battery equalization strategy. However, due to differences in the production and manufacturing processes of different battery packs, even under the same voltage, their charging and discharging states will show significant differences. This results in inaccurate activation of the equalization strategy module during the active equalization process of the storage battery, unable to ensure battery equalization for each single battery in the storage battery, seriously affecting the charging and discharging efficiency of the storage battery, and shortening the service life of the storage battery. Summary of the Invention

[0005] In order to solve the technical problems that the traditional storage battery equalization strategy cannot ensure battery equalization for each single battery in the storage battery, seriously affects the charging and discharging efficiency of the storage battery, and shortens the service life of the storage battery, the purpose of the present invention is to provide a method, device and system for monitoring the state of a storage battery, and the specific technical solutions adopted are as follows: In a first aspect, the present invention provides a method for monitoring the state of a storage battery, the method comprising: Obtaining the capacitance change data and voltage change data of each single battery in each battery pack of the storage battery during discharge; Calculating the abnormal state value and equalization adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data; Based on the abnormal state value and the equalization adjustment characteristic value, performing battery equalization processing respectively within each battery pack; Calculating the battery characteristic consistency between each battery pack according to the equalization adjustment characteristic value, and performing battery equalization processing between each battery pack based on the battery characteristic consistency.

[0006] Optionally, the capacitance change data at least includes the remaining capacitance of the single battery at each discharge moment, the first capacitance of the single battery in the capacitance-time relationship curve at each discharge moment, and the second capacitance of the single battery in the voltage-capacitance relationship curve at each discharge moment. The voltage change data at least includes the voltage time-sequence change data of the single battery in the voltage-time relationship curve within a preset time period; According to the capacitance change data and the voltage change data, calculate the abnormal state value and the balance adjustment characteristic value of each single battery, including: Calculate the first capacitance difference between the first capacitance and the remaining capacitance of each single battery, and the second capacitance difference between the second capacitance and the remaining capacitance; Based on the first capacitance difference, the second capacitance difference, and the total capacitance of the single battery, calculate the abnormal state value of each single battery in each battery pack; Calculate the remaining capacity ratio of the remaining capacitance to the total capacitance of the single battery, and calculate the average voltage change slope of the single battery within the preset time period based on the voltage time-sequence change data; Based on the abnormal state value, the remaining capacity ratio, and the average voltage change slope, calculate the balance adjustment characteristic value of each single battery in each battery pack.

[0007] Optionally, based on the abnormal state value, the remaining capacity ratio, and the average voltage change slope, calculate the balance adjustment characteristic value of each single battery in each battery pack, including: Construct the battery characteristics of each single battery in each battery pack according to the remaining capacity ratio and the average voltage change slope; Based on the battery characteristics of each single battery in each battery pack, calculate the average battery characteristics of each battery pack, and the correlation coefficient between the voltage change and the capacitance change in each battery pack; Calculate the average abnormal state value of the multiple abnormal state values corresponding to the multiple single batteries in each battery pack; Use the battery characteristics, the average battery characteristics, the correlation coefficient, the abnormal state value, and the average abnormal state value to calculate the balance adjustment characteristic value of each single battery in each battery pack.

[0008] Optionally, based on the abnormal state value and the balance adjustment characteristic value, perform battery balancing processing in each of the battery packs, including: Sequentially determine each of the battery packs as the current battery pack, 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 reaches a first preset iteration condition, continue to repeatedly execute the second battery equalization process on the current battery pack based on the equalization adjustment eigenvalue until a second preset iteration condition is reached, and determine that the internal battery equalization adjustment of the current battery pack is completed.

[0009] Optionally, repeatedly executing the first battery equalization process on the current battery pack based on the abnormal state value includes: Determine whether there is an abnormal single battery in the current battery pack corresponding to the abnormal state value greater than a first preset threshold; If it is determined that there is the abnormal single battery in the current battery pack, determine a first single battery and a second single battery in the current battery pack, and control the first single battery to supply electrical energy to the second single battery; Repeatedly execute the above first battery equalization process until it is determined that a first preset iteration condition is reached. The first preset iteration condition is that the abnormal state values corresponding to all single batteries in the current battery pack are less than the first preset threshold, or the cumulative battery equalization duration reaches the maximum equalization duration.

[0010] Optionally, continuing to repeatedly execute the second battery equalization process on the current battery pack based on the equalization adjustment eigenvalue includes: Calculate the battery equalization adjustment parameter of the current battery pack based on the equalization adjustment eigenvalue, and determine whether the battery equalization adjustment parameter is greater than a second preset threshold; If it is determined that the battery equalization adjustment parameter is greater than the second preset threshold, determine a third single battery and a fourth single battery in the current battery pack, and control the third single battery to supply electrical energy to the fourth single battery; Repeatedly execute the above second battery equalization process until it is determined that a second preset iteration condition is reached. 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 duration reaches the maximum equalization duration.

[0011] Optionally, calculating the battery equalization adjustment parameter of the current battery pack based on the equalization adjustment eigenvalue includes: Determine multiple equalization adjustment eigenvalues corresponding to multiple single batteries in the current battery pack; Extract the maximum equalization adjustment eigenvalue and the minimum equalization adjustment eigenvalue from the multiple equalization adjustment eigenvalues; Determine the difference between the maximum value and the minimum value of the balance adjustment feature as the battery balance adjustment parameter of the current battery pack.

[0012] Optionally, calculating the battery feature consistency among the battery packs according to the balance adjustment feature values, and performing battery balance processing among the battery packs based on the battery feature consistency includes: Repeatedly execute the third battery balance processing process until it is determined that a third preset iteration condition is reached. The third preset iteration condition is that the battery feature consistency between any two battery packs is greater than a third preset threshold, or the cumulative battery balance duration reaches the maximum balance duration; Wherein, the third battery balance processing process includes: Based on the balance adjustment feature values of each single battery in each battery pack, calculate the average value of the balance adjustment feature values of each battery pack; Based on the average battery features of each battery pack and the average value of the balance adjustment feature values, calculate the battery feature consistency between any two battery packs; When it is determined that the battery feature consistency between any two battery packs is less than the third preset threshold, determine a first battery pack and a second battery pack in the multiple battery packs corresponding to the storage battery, and control the first battery pack to supply electrical energy to the second battery pack.

[0013] In a second aspect, an embodiment of the present invention provides a storage battery state monitoring device, including: An acquisition module, configured to acquire the capacitance change data and voltage change data of each single battery in each battery pack of the storage battery during discharge; A calculation module, configured to calculate the abnormal state value and the balance adjustment feature value of each single battery according to the capacitance change data and the voltage change data; A first processing module, configured to perform battery balance processing separately within each battery pack based on the abnormal state value and the balance adjustment feature value; A second processing module, configured to calculate the battery feature consistency among the battery packs according to the balance adjustment feature values, and perform battery balance processing among the battery packs based on the battery feature consistency.

[0014] In a third aspect, an embodiment of the present invention further provides a storage battery state monitoring system, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, the steps of the method described in any one of the above are implemented.

[0015] The present invention has the following beneficial effects: Through the technical solution provided by the present invention, it is possible to first obtain the capacitance change data and voltage change data of each single battery in each battery pack of the storage battery during the discharge process. Then, based on the capacitance change data and voltage change data, calculate the abnormal state value and the equalization adjustment characteristic value of each single battery. Further, based on the abnormal state value and the equalization adjustment characteristic value, perform battery equalization processing separately within each battery pack. Finally, calculate the battery characteristic consistency between each battery pack based on the equalization adjustment characteristic value, and perform battery equalization processing between each battery pack based on the battery characteristic consistency. By obtaining the capacitance change data and voltage change data of each single battery in each battery pack during the discharge process, the present invention can provide more comprehensive battery state information compared with the traditional method that only relies on the voltage difference. Based on the capacitance change data and voltage change data, battery equalization within the battery pack and between battery packs is carried out successively during the discharge process of the storage battery. Under the dual action of in-battery-pack and inter-battery-pack equalization, the individual differences of each single battery can be fully considered, so as to ensure that each single battery in the storage battery can achieve battery equalization, further improving the charge and discharge efficiency of the storage battery and extending the service life of the storage battery.

[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. Other features and advantages of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic flow chart of a method for monitoring the state of a storage battery provided by an embodiment of the present invention; Figure 2 It is a schematic flow chart of a method for monitoring the state of a storage battery provided by another embodiment of the present invention; Figure 3 It is a schematic structural diagram of a device for monitoring the state of a storage battery provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0019] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details a method, device, and system for monitoring the state of a storage battery according to the present invention, including its specific implementation manner, structure, features, and effects, as follows. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0021] The following specifically describes the specific solutions of a method, device, and system for monitoring the state of a storage battery provided by the present invention in conjunction with the accompanying drawings.

[0022] Please refer to Figure 1 , which shows a flowchart of a method for monitoring the state of a storage battery provided by an embodiment of the present invention. The method includes the following steps: Step 110: Obtain the capacitance change data and voltage change data of each single battery in each battery pack of the storage battery during the discharge process.

[0023] During the discharge process of the battery, single batteries with smaller capacities or larger internal resistances will reach the discharge cut-off threshold first. Continuing to discharge after reaching the threshold will result in over-discharge, affecting the service life of the storage battery. Therefore, it is not possible to rely solely on the voltage difference to determine whether to perform battery equalization.

[0024] In a specific application scenario, the storage battery to be monitored for its state may include multiple battery packs, and each battery pack may contain multiple single batteries. When monitoring the state of the storage battery, the capacitance and voltage change data of the single batteries in the battery pack can be obtained. These data can help accurately judge the battery state and provide a strong basis for subsequent battery equalization strategies. Among them, the capacitance change data may at least include the remaining capacitance of the single battery at each discharge moment , the first capacitance of the single battery in the capacitance-time relationship curve at each discharge moment , and the second capacitance of the single battery in the voltage-capacitance relationship curve at each discharge moment . The voltage change data may at least include the voltage time-series change data of the single battery in the voltage-time relationship curve within a preset time period.

[0025] Among them, the remaining capacitance It is the actual remaining charge that can be released by the battery at a certain discharge moment. In actual application scenarios, such as when an electric vehicle is running, it can enable users to intuitively know the remaining driving range that the battery can support. The capacitance-time relationship curve is a theoretical curve drawn based on the discharge condition of a single battery under standard test conditions. On this curve, each discharge moment corresponds to a theoretical capacitance value, that is, the first capacitance. The voltage-capacitance relationship curve reflects the internal relationship between the battery voltage and the capacitance. Due to factors such as battery internal resistance, polarization effect, and aging, the relationship between voltage and capacitance is not fixed. At each discharge moment, according to the actual voltage of the single battery, the corresponding capacitance, that is, the second capacitance, can be found on this curve. It is the voltage time-series change data of the single battery in the voltage-time relationship curve within a preset time period, which records the change of the single battery voltage over time within a preset period of time.

[0026] Step 120: Calculate the abnormal state value and the balance adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data.

[0027] Among them, the abnormal state value (b value) is mainly calculated based on the capacitance change data, and the b value reflects the abnormal state of the single battery. The larger the b value, the greater the deviation between the actual capacitance and the theoretical capacitance, and the greater the battery capacity consumption in the same time, indicating that the battery may have performance problems and other batteries need to supplement electric energy to maintain balance; the smaller the b value, the more it indicates that the single battery is in a normal charge and discharge state. For example, if the b value of a certain single battery far exceeds the set threshold (such as 0.2%), it means that the performance of this battery is quite different from that of other batteries and balance adjustment is urgently needed. The calculation of the balance adjustment characteristic value (c value) can comprehensively consider the capacitance change data and the voltage change data, and it is used to measure the necessity of balance adjustment of the single battery.

[0028] Step 130: Perform battery balance processing within each battery group based on the abnormal state value and the balance adjustment characteristic value.

[0029] For the embodiments of the present disclosure, two battery balance processes will be performed successively within each battery group. For the same battery group, a battery balance process can be first performed within the battery group based on the abnormal state value, and then a battery balance process can be continued within the battery group based on the balance adjustment characteristic value.

[0030] The abnormal state value (b value) comprehensively reflects the deviation degree between the actual situation and the theoretical situation of the capacitance of a single battery. It is obtained by comparing the capacitance differences of a single battery under different calculation methods. When the b value is greater than the set threshold (such as 0.2%), it indicates that there are single batteries with abnormal discharge in the battery pack. These abnormal batteries may have a relatively fast capacity attenuation or a large internal resistance, resulting in different discharge characteristics from other batteries. When performing battery equalization processing within a certain battery pack based on the abnormal state value, specifically through the box plot anomaly detection model, the single batteries in the battery pack can be divided into two categories (M1 and M2). The b value of the M1 category of batteries (i.e., the first single battery) is relatively small, which means its discharge is relatively normal and can be used as the electrical energy output side; the b value of the M2 category of batteries (i.e., the second single battery) is relatively large and the discharge is abnormal, and electrical energy supplementation is required. This classification provides a basis for the preliminary equalization within the battery pack. By controlling the first single battery to supplement electrical energy to the second single battery, electrical energy can flow from the relatively normal battery to the abnormal battery, initially balancing the electrical energy of each single battery in the battery pack.

[0031] The equalization adjustment characteristic value (c value) further comprehensively considers various factors such as the voltage change of the battery, the proportion of the remaining capacity, and the difference from the average characteristics of the battery pack. It more accurately measures the difference degree between a single battery and the overall state of the battery pack through complex calculations (including the voltage change slope, correlation coefficient r, etc.). When performing battery equalization processing within a certain battery pack based on the equalization adjustment characteristic value, specifically, the range Rc of the single batteries in the battery pack with respect to the equalization adjustment characteristic value can be calculated. When Rc is greater than the set threshold (such as 0.1), it indicates that the discharge differences of the single batteries in the battery pack are relatively large and further equalization is required. Then, anomaly detection can be performed on the single batteries according to the range Rc, and the single batteries in the battery pack can be divided into two categories (M(1) and M(-1)). The characteristics of the M(1) category of batteries (i.e., the third single battery) are relatively good and can supplement electrical energy to the M(-1) category of batteries (i.e., the fourth single battery) with abnormal discharge, further optimizing the equalization state within the battery pack.

[0032] Within the battery pack, the above-mentioned battery equalization processing operations within the battery pack are continuously performed based on the b value and the c value. After each adjustment, the b value and the c value are recalculated, and it is determined again whether further equalization is required until the preset iteration condition for loop termination is reached. Through this continuously loop-optimized method, the single batteries in the battery pack are made to be in a similar discharge state as much as possible, reducing the problem of the overall performance degradation of the battery pack caused by the inconsistency of the single batteries, improving the charge and discharge efficiency of the battery pack, and extending the service life of the battery pack.

[0033] Step 140: Calculate the battery characteristic consistency between each battery pack according to the equalization adjustment characteristic value, and perform battery equalization processing between each battery pack based on the battery characteristic consistency.

[0034] In a battery energy storage system, multiple battery packs work together, and each battery pack consists of multiple single cells. Due to differences in production processes, usage environments, etc. among different battery packs, the comprehensive performance of the single cells inside them varies, which in turn leads to different overall discharge states of each battery pack. Calculating the battery characteristic consistency between battery packs and performing balancing processing based on this is crucial for improving the performance of the entire battery energy storage system.

[0035] For the embodiments of the present disclosure, in order to measure the consistency between battery packs, the battery characteristic consistency between battery packs can be calculated based on the balance adjustment characteristic value. When the calculated battery characteristic consistency is greater than a preset threshold (such as 0.9), it indicates that the consistency between different battery packs is strong and their states during discharge are relatively similar. In this case, no balancing processing between battery packs is required. When the battery characteristic consistency is less than the preset threshold (such as 0.9), it shows that there are significant differences between battery packs and balancing adjustment is needed. When it is determined that balancing processing between battery packs is required, the operation process is similar to the balancing processing inside the battery pack based on the balance adjustment characteristic value c. That is, according to the relevant characteristics of each battery pack, the battery packs are divided into two categories, and one category of battery packs transfers electrical energy to the other category to balance the charge differences between different battery packs.

[0036] In this way, each battery pack can work more coordinately during discharge, avoiding affecting the performance and lifespan of the entire battery energy storage system due to over-discharge or over-charge of some battery packs. For example, in an energy storage system composed of multiple battery packs, if some battery packs discharge too fast, through the balancing processing between battery packs, electrical energy can be transferred from the battery packs with slower discharge, so that the discharge progress of all battery packs remains relatively consistent, improving the stability and reliability of the energy storage system.

[0037] In summary, according to a battery state monitoring method provided by the present invention, it is possible to first obtain the capacitance change data and voltage change data of each single battery in each battery pack of the battery during the discharge process. Then, based on the capacitance change data and voltage change data, calculate the abnormal state value and the balance adjustment characteristic value of each single battery. Further, based on the abnormal state value and the balance adjustment characteristic value, perform battery balance processing within each battery pack respectively. Finally, calculate the battery characteristic consistency between each battery pack according to the balance adjustment characteristic value, and perform battery balance processing between each battery pack based on the battery characteristic consistency. By obtaining the capacitance change data and voltage change data of each single battery in each battery pack during the discharge process, compared with the traditional method that only relies on the voltage difference, the present invention can provide more comprehensive battery state information. Based on the capacitance change data and voltage change data, battery balance within the battery pack and battery balance between battery packs are performed successively during the discharge process of the battery. Under the dual action of balance within the battery pack and between battery packs, the individual differences of each single battery can be fully considered, so as to ensure that each single battery in the battery can achieve battery balance, further improving the charge and discharge efficiency of the battery and extending the service life of the battery.

[0038] Based on Figure 1 the embodiments shown, as a refinement and extension of the above embodiments, in order to fully illustrate the specific implementation process of the method in this embodiment, this embodiment provides the specific method as shown in Figure 2 the following. Figure 2 Based on Figure 1 the embodiments shown. As shown in Figure 2 the following, the method includes the following steps: Step 210: Obtain the capacitance change data and voltage change data of each single battery in each battery pack of the battery during the discharge process.

[0039] Among them, the capacitance change data may at least include the remaining capacitance of the single battery at each discharge moment , the first capacitance of the single battery in the capacitance-time relationship curve at each discharge moment , and the second capacitance of the single battery in the voltage-capacitance relationship curve at each discharge moment . The voltage change data may at least include the voltage time series change data of the single battery in the voltage-time relationship curve within a preset time period.

[0040] Step 220: Calculate the abnormal state value and the balance adjustment characteristic value of each single battery according to the capacitance change data and voltage change data.

[0041] Correspondingly, for the embodiments of the present disclosure, calculating the abnormal state value and the balancing adjustment eigenvalue of each single battery according to the capacitance change data and the voltage change data in step 220 may include the following steps: Step 220-1: Calculate the first capacitance difference between the first capacitance and the remaining capacitance of each single battery, and the second capacitance difference between the second capacitance and the remaining capacitance.

[0042] The first capacitance difference refers to the difference between the first capacitance and the remaining capacitance of each single battery. Among them, the first capacitance is the theoretical capacitance value corresponding to each discharge moment in the capacitance-time relationship curve of the single battery. The remaining capacitance is the actual remaining charge that can be released by the single battery within the current 1s monitored by methods such as ampere-hour integration during the discharge process of the single battery. The calculation process of the first capacitance difference is expressed by the formula: , where, represents the first capacitance difference, represents the first capacitance, and Q represents the remaining capacitance. The first capacitance difference reflects the deviation degree between the actual discharge situation and the theoretical discharge situation of the battery. Due to individual differences in the production process of the battery and the occurrence of aging and performance decline during use, the actual discharge performance is often different from the theoretical situation. If the absolute value of the first capacitance difference is large and negative, it means that the actual capacitance consumed by the current single battery is larger than the capacitance that should be consumed theoretically at this moment, and there may be a problem of too fast capacitance decay; if it is positive, it means that the actual consumed capacitance is less than the theoretical value. By analyzing the first capacitance difference, the capacity change trend and health status of the single battery can be initially judged, providing an important basis for whether battery balancing is needed subsequently.

[0043] The second capacitance difference is the difference between the second capacitance and the remaining capacitance of each single battery. The second capacitance is the capacitance corresponding to the current voltage of the single battery according to the voltage-capacitance relationship curve of the single battery. The calculation process of the second capacitance difference is also expressed by the formula: , where, represents the second capacitance difference, Let \(C_2\) represent the second capacitance, and \(Q\) represent the remaining capacitance. The difference in the second capacitance reflects the real-time state of the battery. The relationship between the voltage and capacitance of the battery is affected by various factors such as internal resistance, polarization effect, and aging degree. When the absolute value of the difference in the second capacitance is large, it means that the voltage-capacitance mapping relationship of the battery deviates from the theoretical model. For example, it may be that the increase in internal resistance causes the voltage to change at the same capacitance, or the voltage-capacitance curve changes due to polarization effect, aging, etc. This difference can help further understand the physical and chemical changes inside the battery, assist in judging whether the battery needs to be balanced, and how to perform more accurate balancing operations.

[0044] Step 220-2: Calculate the abnormal state value of each single battery in each battery pack based on the first capacitance difference, the second capacitance difference, and the total capacitance of the single battery.

[0045] In the battery state monitoring system, the abnormal state value of a single battery is crucial for judging the battery health status and implementing the balancing strategy. Calculating the abnormal state value based on the first capacitance difference, the second capacitance difference, and the total capacitance of the single battery can comprehensively consider multi-dimensional information and accurately evaluate the state of the single battery.

[0046] For the embodiments of the present disclosure, when calculating the abnormal state value of each single battery in each battery pack, the first capacitance difference, the second capacitance difference, and the total capacitance of the single battery can be first substituted into the first calculation formula to calculate the intermediate parameter of the capacitance difference ratio. Further, the first capacitance difference, the second capacitance difference, and the capacitance difference ratio are substituted into the second calculation formula to calculate the abnormal state value of the corresponding single battery. The capacitance difference ratio comprehensively reflects the relationship between the first and second capacitance differences and the total capacitance, and is used to measure the proportion of the capacitance difference in the total capacitance under different calculation methods.

[0047] Among them, the formula feature description of the first calculation formula is: ; In the formula, represents the capacitance difference ratio of a certain single battery; represents the first capacitance difference of this single battery; represents the second capacitance difference of this single battery; represents the total capacitance of this single battery; reflects the absolute value of the difference between two different capacitance calculation methods, divided by the total capacitance and multiplied by , the difference can be normalized to a ratio value, which is convenient for comparison between different batteries.

[0048] The formula feature description of the second calculation formula is: ; In the formula, represents the abnormal state value of a certain single cell; represents the proportion of the capacitance difference of the single cell; represents the first capacitance difference of the single cell; represents the second capacitance difference of the single cell; represents the overall fluctuation range of the two capacitance differences, is a normalization function, is to normalize this fluctuation range so that it can be measured on a unified scale. The larger the value, the greater the deviation between the actual capacitance and the theoretical capacitance, the greater the battery capacity consumption in the same time, the more the single cell deviates from the normal state, and the more balance processing is required to maintain the consistency of the performance of each battery in the battery pack; on the contrary, the smaller the value, the greater the possibility that the single cell is in a normal charge and discharge state.

[0049] Step 220-3: Calculate the remaining capacity ratio of the remaining capacitance relative to the total capacitance of the single cell, and calculate the average value of the voltage change slope of the single cell within a preset time period based on the voltage time series change data.

[0050] The remaining capacity ratio refers to the ratio of the remaining capacitance to the total capacitance of the single cell. It is expressed by the formula: . Among them, represents the remaining capacity ratio of a certain single cell, and Q represents the remaining capacitance of the single cell; is the total capacitance of the single cell, that is, the amount of electricity that the battery can store under ideal conditions, which is an inherent property of the battery. The remaining capacity ratio intuitively shows the current power state of the battery. For example, =0.5 means that the battery has half of its remaining power. It is of great significance in judging the battery state and balance requirements. For example, when comparing the discharge progress of different single cells, the remaining capacity ratio can clearly show the degree of power difference between each battery. If the remaining capacity ratios of different single cells in the same battery pack vary greatly, balance processing may be required to ensure that the discharge progress of each battery is consistent and improve the overall performance of the battery pack.

[0051] The average value of the voltage change slope is calculated based on the voltage time series change data. Specifically, within a preset time period (such as 1 s), multiple voltage time series change data of the single cell can be obtained. Each voltage time series change data contains the voltage change and the corresponding time difference . Through the formula , the voltage change slope 。Then, average the multiple voltage change slopes corresponding to the multiple voltage time-series change data within the preset time period to obtain the average value of the voltage change slope (VK). This average value reflects the average rate of voltage change of the single cell within the preset time period. Under normal circumstances, the voltage change during battery discharge should be relatively stable, with a small and relatively uniform average value of the voltage change slope. If the average value of the voltage change slope is large, it means that the voltage fluctuates violently during this time period, which may indicate abnormalities in the battery, such as changes in internal resistance and unstable internal chemical reactions. This requires further analysis to determine whether battery balancing adjustment is needed. However, since the voltage change speed of the battery is different at different remaining charge levels (slow change when fully charged and fast change when low on charge), the average value of the voltage change slope needs to be combined with other indicators such as the remaining capacity ratio to comprehensively judge the battery state.

[0052] Step 220-4: Calculate the balancing adjustment characteristic value of each single cell in each battery pack based on the abnormal state value, the remaining capacity ratio, and the average value of the voltage change slope.

[0053] Remaining capacity ratio and the average value of the voltage change slope VK reflect the state of the single cell from different perspectives. The remaining capacity ratio shows the proportion of the current remaining charge of the battery in the total charge, reflecting the battery's charge level; the average value of the voltage change slope VK reflects the average rate of voltage change of the battery within the preset time period, reflecting the voltage stability during battery discharge. Combining these two parameters can construct the battery characteristics of each single cell in each battery pack , and such a battery characteristic vector can comprehensively describe the state of the single cell in terms of voltage and charge, providing basic data for subsequent analysis. Among them, when using the remaining capacity ratio and the average value of the voltage change slope VK to construct the battery characteristics , any conventional characteristic construction method can be used, which will not be elaborated here. Further, based on the battery characteristics of each single cell in each battery pack , calculate the average value of the battery characteristics of the battery pack This is the result obtained by averaging the battery characteristics of all single cells in the battery pack, which represents the average characteristic level of the battery pack. In addition, the correlation coefficient r between the voltage change and the capacitance change in each battery pack can also be calculated based on the battery characteristics of each single cell in the battery pack. This coefficient reflects the degree of association between the voltage change and the capacitance change during the discharge process of the battery pack. If the absolute value of r is close to 1, it indicates a strong linear relationship between the voltage change and the capacitance change; if r is close to 0, it means the relationship between the two is weak. By analyzing the correlation coefficient, the stability and consistency of the battery pack during the discharge process can be judged. For example, if the r value of a certain battery pack is small (negative correlation), it means that during the discharge of this battery pack, the association between the voltage change and the capacitance change is not very tight, and there may be abnormal states of some single cells, which requires further attention. Further, the average value of abnormal state values corresponding to multiple single cells in each battery pack can also be calculated. of the abnormal state . The abnormal state value is calculated based on the first capacitance difference, the second capacitance difference, etc., and reflects the degree of deviation of the single cell from the normal state. By calculating the average value of abnormal state , the average level of the abnormal states of the single cells in the battery pack can be understood, and the health status of the entire battery pack can be evaluated. If is large, it indicates that the overall deviation of the single cells in this battery pack from the normal state is relatively high, and the possibility of requiring balancing processing is relatively large. Finally, the battery characteristics , the average value of battery characteristics , the correlation coefficient r, the abnormal state value and the average value of abnormal state can be substituted into the third calculation formula to calculate the balancing adjustment characteristic value of each single cell in each battery pack.

[0054] Among them, the formula characteristics of the third calculation formula are described as: ; In the formula, represents the balancing adjustment characteristic value of a certain single cell; represents the abnormal state value of this single cell; represents the average value of abnormal state values corresponding to multiple single cells in the battery pack where this single cell is located ; is the symbol for vector norm calculation; represents the degree of difference between the abnormal state value of this single cell and the average abnormal state of the battery pack. The greater the difference, the more obvious the difference in the abnormal states between this single cell and other cells in the battery pack, and the more balancing adjustment is required; is the correlation coefficient between the voltage change and the capacitance change in the battery pack where this single cell is located; To normalize the correlation coefficient ; is the battery characteristic of the single battery; represents the mean value of the battery characteristics corresponding to multiple single batteries in the battery pack where the single battery is located; reflects the difference between the battery characteristic of the single battery and the average characteristic of the battery pack, and reflects the particularity of the single battery in the battery pack; represents the difference between the battery characteristic of the single battery and the ideal battery characteristic. The smaller this value is, the closer the single battery is to the ideal state, and the less the need for balancing adjustment.

[0055] Correspondingly, for the embodiments of the present disclosure, the embodiment steps may include: constructing the battery characteristics of each single battery in each battery pack according to the remaining capacity ratio and the average value of the voltage change slope; based on the battery characteristics of each single battery in each battery pack, calculating the average value of the battery characteristics of each battery pack, and the correlation coefficient between the voltage change and the capacitance change in each battery pack; calculating the average value of the abnormal states of multiple abnormal state values corresponding to multiple single batteries in each battery pack; using the battery characteristics, the average value of the battery characteristics, the correlation coefficient, the abnormal state value, and the average value of the abnormal state, calculating the balancing adjustment characteristic value of each single battery in each battery pack.

[0056] Step 230: Sequentially determine each battery pack as the current battery pack, and repeatedly execute the first battery balancing process on the current battery pack based on the abnormal state value.

[0057] For the embodiments of the present disclosure, repeatedly executing the first battery balancing process on the current battery pack based on the abnormal state value in step 230 may include the following steps: Step 230-1: Determine whether there is an abnormal single battery in the current battery pack whose corresponding abnormal state value is greater than the first preset threshold.

[0058] Among them, the first preset threshold can be set according to the actual application scenario, such as it can be set to 0.2.

[0059] Step 230-2: If it is determined that there is an abnormal single battery in the current battery pack, determine the first single battery and the second single battery in the current battery pack, and control the first single battery to supplement electric energy to the second single battery.

[0060] For the embodiments of the present disclosure, after determining that there is an abnormal single battery in the battery pack, it is necessary to find suitable first and second single batteries. Generally, the single batteries in the battery pack can be analyzed through the box plot anomaly detection model. The battery abnormal state value of the battery pack Input it into the box plot anomaly detection model, and output the set of abnormal single cells located outside the box plot. The batteries in the abnormal state are divided into two categories (M1 and M2) according to whether the data is above or below the box plot. The M1-type batteries below indicate being smaller. These batteries are relatively normal and serve as the first single cell; the M2-type batteries above indicate being larger. These batteries have abnormal discharges and serve as the second single cell. After determining the first single cell and the second single cell, it is necessary to take measures to let the first single cell supply electrical energy to the second single cell. This is the key step to achieve balance within the battery pack. In actual operation, the circuit switch is usually controlled by a Battery Management System (BMS) to make the electrical energy flow from the first single cell to the second single cell. For example, using circuit components such as inductors, capacitors, or DC-DC converters, the electrical energy of the first single cell is transferred to the second single cell, so that the charge of the second single cell is replenished, thereby reducing the charge difference between the single cells in the battery pack, improving the overall performance of the battery pack, and avoiding problems such as reduced charge and discharge efficiency and shortened lifespan of the battery pack caused by excessive differences between single cells.

[0061] Step 230-3: Repeat the above first battery balancing process 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 duration reaches the maximum balancing duration.

[0062] Among them, the maximum balancing duration can be set according to the actual application scenario. For example, it can be set to 5 minutes.

[0063] Step 240: After determining that the first battery balancing process meets the first preset iteration condition, continue to repeat the second battery balancing process for the current battery pack based on the balance adjustment eigenvalue until the second preset iteration condition is met, and determine that the internal battery balance adjustment of the current battery pack is completed.

[0064] For the embodiments of the present disclosure, the step of continuing to repeat the second battery balancing process for the current battery pack based on the balance adjustment eigenvalue in step 240 may include the following steps: Step 240-1: Calculate the battery balance adjustment parameter of the current battery pack based on the balance adjustment eigenvalue, and determine whether the battery balance adjustment parameter is greater than the second preset threshold.

[0065] For the embodiments of the present disclosure, when calculating the battery balance adjustment parameter of the current battery pack based on the balance adjustment eigenvalue, among the multiple balance adjustment eigenvalues of multiple single cells in the battery pack find the maximum value among them and the minimum value These two values represent two extreme cases of the single cells in the battery pack in terms of the need for balancing adjustment. The corresponding single cell may have the largest difference from the overall state of the battery pack and thus requires the most balancing adjustment; The corresponding single cell has a relatively smaller difference from the overall state. "Balancing" here does not refer to the actual transfer of electrical energy, but rather by analyzing these two extreme values, understanding the range of differences in the states of the single cells in the battery pack, providing a basis for determining the subsequent adjustment strategy. For example, if is very large, is very small, it indicates that the differences in the states of the single cells in the battery pack are relatively large and need to be focused on and balanced. Further, the difference between and can be calculated, that is , and this difference is the battery balancing adjustment parameter of the current battery pack. The larger the value of , the greater the difference in the actual discharge conditions of the single cells in the battery pack, and the higher the necessity for balancing adjustment. For example, when exceeds the set threshold (such as 0.1), it is necessary to balance the single cells in the battery pack. By distributing electrical energy to single cells in different states, their states can be made to tend to be consistent, thereby improving the overall performance of the battery pack, such as charge and discharge efficiency, service life, etc.

[0066] Correspondingly, the steps of the embodiment may include: determining a plurality of balancing adjustment characteristic values corresponding to a plurality of single cells in the current battery pack; extracting the maximum and minimum balancing adjustment characteristic values among the plurality of balancing adjustment characteristic values; and determining the difference between the maximum and minimum balancing adjustment characteristic values as the battery balancing adjustment parameter of the current battery pack.

[0067] Step 240-2: If it is determined that the battery balancing adjustment parameter is greater than the second preset threshold, determine a third single cell and a fourth single cell in the current battery pack, and control the third single cell to supply electrical energy to the fourth single cell.

[0068] Among them, the second preset threshold can be set according to the actual application scenario, such as being set to 0.1. When is greater than this second preset threshold, it indicates that the differences in the actual discharge conditions of the single cells in the current battery pack are relatively large. For example, if = 0.15, which is greater than the preset threshold of 0.1, this means that some single cells in the battery pack discharge too fast or too slow, with an obvious difference from the states of other single cells. If not adjusted, it will affect the overall performance and service life of the battery pack. At this time, it is necessary to initiate the battery balancing measure.

[0069] Once it is determined that balance adjustment is required, appropriate third and fourth single cells need to be determined within the current battery pack. This is usually determined based on various characteristic values of the single cells calculated previously (such as the abnormal state value b, the balance adjustment characteristic value c, etc.) and relevant markings. For example, after abnormal detection of the single cells, the abnormal single cells are divided into two categories and marked as M(1) and M(-1). The single cells in the M(1) category are relatively normal and can be used as the third single cell, which has the ability to supply electrical energy to other batteries; the single cells in the M(-1) category have abnormal discharge and need electrical energy supplementation, and are used as the fourth single cell. Through such classification and selection, the direction and object of power transfer are clarified. After determining the third and fourth single cells, the battery management system (BMS) can also be used to control the realization of power transfer. The BMS will operate relevant electronic components (such as switches, DC-DC converters, etc.) through specific circuits and control algorithms, so that the electrical energy of the third single cell flows to the fourth single cell. During this process, the BMS will monitor the state parameters of the battery (such as voltage, current, etc.) in real time to ensure the safety and stability of the power transfer process.

[0070] Step 240-3: Repeat the above second battery balance processing process until it is determined that the second preset iteration condition is met. The second preset iteration condition is that the battery balance adjustment parameter corresponding to the current battery pack is less than the second preset threshold, or the cumulative battery balance duration reaches the maximum balance duration.

[0071] Among them, the maximum balance duration can be set according to the actual application scenario. For example, it can be set to 5 minutes.

[0072] Step 250: Calculate the battery characteristic consistency between each battery pack according to the balance adjustment characteristic value, and perform battery balance processing between each battery pack based on the battery characteristic consistency.

[0073] For the embodiments of the present disclosure, when calculating the battery characteristic consistency between each battery pack according to the balance adjustment characteristic value in step 250 and performing battery balance processing between each battery pack based on the battery characteristic consistency, the third battery balance processing process can be repeated until it is determined that the third preset iteration condition is met. The third preset iteration condition is that the battery characteristic consistency between any two battery packs is greater than the third preset threshold, or the cumulative battery balance duration reaches the maximum balance duration. Among them, the third preset threshold can be set according to the actual application scenario. For example, it can be set to 0.9; the maximum balance duration can be set according to the actual application scenario. For example, it can be set to 5 minutes.

[0074] The third battery balance processing process may include the following steps: Step 250-1: Calculate the average value of the balance adjustment characteristic values of each battery pack based on the balance adjustment characteristic values of each single cell within each battery pack.

[0075] For a battery pack that includes multiple single cells, each single cell has its own equalization adjustment characteristic value . Calculate the average value of the equalization adjustment characteristic values of the battery pack , which is to sum up the equalization adjustment characteristic values of all single cells in the group and then calculate the average value. The average value of the equalization adjustment characteristic values can represent the overall equalization status of the battery pack. If the average value of the equalization adjustment characteristic values of a battery pack is small, it indicates that the states of the single cells in the battery pack are relatively consistent and the overall equalization is good; conversely, if the average value is large, it means that there are large differences between the single cells in the battery pack, and the equalization of the battery pack is poor, and key attention needs to be paid and corresponding equalization measures may be taken to improve the performance of the battery pack.

[0076] Step 250-2: Calculate the battery characteristic consistency between any two battery packs based on the average battery characteristics and the average value of the equalization adjustment characteristic values of each battery pack.

[0077] For the embodiments of the present disclosure, the average battery characteristics and the average value of the equalization adjustment characteristic values corresponding to any two battery packs can be obtained, and then the average battery characteristics and the average value of the equalization adjustment characteristic values of the two groups are substituted into the fourth calculation formula to calculate the battery characteristic consistency between the two battery packs.

[0078] Among them, the formula characteristics of the fourth calculation formula are described as follows: ; In the formula, represents the battery characteristic consistency between the i-th and j-th battery packs in the storage battery; is a normalization function used to map the calculation result to a specific interval for convenient comparison; is the average battery characteristic of the i-th battery pack; is the average value of the equalization adjustment characteristic values of the i-th battery pack; is the average battery characteristic of the j-th battery pack; is the average value of the equalization adjustment characteristic values of the j-th battery pack; is used to calculate the cosine similarity of the average feature vectors of two battery packs to measure the similarity of their directions in the feature space. The closer the cosine value is to 1, the more similar the trends of the two battery packs in terms of voltage change and power state are; represents the difference between the average values of the equalization adjustment characteristic values of the two battery packs. The smaller this value is, the smaller the difference between the two battery packs in terms of equalization. The battery characteristic consistency The larger the value, the more similar the discharge states of different battery packs are, the stronger the consistency is, and they can better maintain synchronization during collaborative work, reducing the degradation of system performance caused by differences in battery packs. For example, in the battery system of an electric vehicle, if the characteristic consistency between each battery pack is high, during the charging and discharging process, each battery pack can share electrical energy more evenly, avoiding overcharging and over-discharging of some battery packs, thereby improving the overall efficiency and safety of the battery system and extending the service life of the battery. On the contrary, if the value is small, it indicates that there are significant differences between the battery packs, and corresponding balancing measures need to be taken to improve the consistency to ensure the stable operation of the system. It should be noted that to ensure the meaningfulness of the calculation results, in the embodiments of the present invention, when performing fractional operations and encountering the situation where the denominator is 0, a tuning factor greater than 0 needs to be added to the denominator to prevent the denominator from being 0. The value of the tuning factor is set by the implementer according to the actual situation, and this application does not make special restrictions.

[0079] Step 250-3: When it is determined that the battery characteristic consistency between any two battery packs is less than the third preset threshold, determine the first battery pack and the second battery pack within the multiple battery packs corresponding to the storage battery, and control the first battery pack to supply electrical energy to the second battery pack.

[0080] Once it is determined that there is a situation where the battery characteristic consistency is less than the third preset threshold, it is necessary to determine the first battery pack and the second battery pack within the multiple battery packs. The specific determination method usually depends on the relevant characteristic values and marks of the battery packs. Generally, a battery pack with a relatively better state and more sufficient power is selected as the first battery pack, and a battery pack with a worse state and in need of electrical energy replenishment is determined as the second battery pack. For example, when analyzing the average characteristics of each battery pack and the mean value of the balancing adjustment characteristic values, those battery packs with a smaller mean value of the balancing adjustment characteristic values and whose average battery characteristics are closer to the ideal state may be determined as the first battery pack; on the contrary, those battery packs with a larger mean value and deviating from the ideal state may become the second battery pack.

[0081] After determining the first battery pack and the second battery pack, it is necessary to control the first battery pack to supplement electrical energy to the second battery pack. This process can also be executed by the Battery Management System (BMS). The BMS will operate relevant electronic components (such as switches, power converters, etc.) through specific circuits and control strategies to achieve the safe and stable transfer of electrical energy from the first battery pack to the second battery pack. During the electrical energy supplementation process, the BMS will monitor parameters such as the voltage, current, and temperature of the battery pack in real time to ensure that the supplementation process will not damage the battery. For example, when it is detected that the voltage of the second battery pack is low, the BMS will adjust the circuit to make the first battery pack charge the second battery pack with an appropriate current until the state difference between the two battery packs is reduced and the battery characteristic consistency is improved to a reasonable range, thereby optimizing the performance of the entire battery system, extending the service life of the battery, and ensuring the stable operation of the system.

[0082] In summary, for the technical solution in this application, it is possible to first obtain the capacitance change data and voltage change data of each single battery in each battery pack of the battery during the discharge process, and then calculate the abnormal state value and the balance adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data; further, based on the abnormal state value and the balance adjustment characteristic value, battery balance processing is respectively performed within each battery pack; finally, the battery characteristic consistency between each battery pack is calculated according to the balance adjustment characteristic value, and battery balance processing is performed between each battery pack based on the battery characteristic consistency. By obtaining the capacitance change data and voltage change data of each single battery in each battery pack during the discharge process, compared with the traditional method that only relies on the voltage difference, the present invention can provide more comprehensive battery state information. Based on the capacitance change data and voltage change data, battery balance within the battery pack and battery balance between battery packs are successively performed during the discharge process of the battery. Under the dual effects of battery balance within the battery pack and between battery packs, the individual differences of each single battery can be fully considered, so as to ensure that each single battery in the battery can achieve battery balance, and further improve the charge and discharge efficiency of the battery and extend the service life of the battery.

[0083] Based on the above Figure 1 、 2 specific description of the battery state monitoring method provided, as Figure 3 shown, Figure 3 is a schematic structural diagram of a battery state monitoring device shown according to an exemplary embodiment. As Figure 3 shown, the device includes: An acquisition module 31, which can be used to acquire the capacitance change data and voltage change data of each single battery in each battery pack of the battery during the discharge process; A calculation module 32, which can be used to calculate the abnormal state value and the balance adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data; The first processing module 33 can be used to perform battery equalization processing within each battery pack respectively based on the abnormal state value and the equalization adjustment eigenvalue. The second processing module 34 can be used to calculate the battery characteristic consistency between each battery pack according to the equalization adjustment eigenvalue, and perform battery equalization processing between each battery pack based on the battery characteristic consistency.

[0084] In a specific application scenario, the capacitance change data at least includes the remaining capacitance of each single battery at each discharge moment, the first capacitance of each single battery in the capacitance-time relationship curve at each discharge moment, and the second capacitance of each single battery in the voltage-capacitance relationship curve at each discharge moment. The voltage change data at least includes the voltage time-sequence change data of each single battery in the voltage-time relationship curve within a preset time period. The calculation module 32 can specifically be used to calculate the first capacitance difference between the first capacitance and the remaining capacitance of each single battery, and the second capacitance difference between the second capacitance and the remaining capacitance. Based on the first capacitance difference, the second capacitance difference, and the total capacitance of the single battery, calculate the abnormal state value of each single battery within each battery pack. Calculate the remaining capacity ratio of the remaining capacitance relative to the total capacitance of the single battery, and calculate the average value of the voltage change slope of each single battery within a preset time period based on the voltage time-sequence change data. Based on the abnormal state value, the remaining capacity ratio, and the average value of the voltage change slope, calculate the equalization adjustment eigenvalue of each single battery within each battery pack.

[0085] In a specific application scenario, when calculating the equalization adjustment eigenvalue of each single battery within each battery pack based on the abnormal state value, the remaining capacity ratio, and the average value of the voltage change slope, the calculation module 32 can specifically be used to construct the battery characteristics of each single battery within each battery pack according to the remaining capacity ratio and the average value of the voltage change slope. Based on the battery characteristics of each single battery within each battery pack, calculate the average value of the battery characteristics of each battery pack, and the correlation coefficient between the voltage change and the capacitance change within each battery pack. Calculate the average value of the abnormal state of the multiple abnormal state values corresponding to the multiple single batteries within each battery pack. Use the battery characteristics, the average value of the battery characteristics, the correlation coefficient, the abnormal state value, and the average value of the abnormal state to calculate the equalization adjustment eigenvalue of each single battery within each battery pack.

[0086] In a specific application scenario, the first processing module 33 can specifically be used to sequentially determine each battery pack as the current battery pack, and repeatedly execute the first battery equalization processing process on the current battery pack based on the abnormal state value. After determining that the first battery equalization processing process reaches the first preset iteration condition, continue to repeatedly execute the second battery equalization processing process on the current battery pack based on the equalization adjustment eigenvalue until the second preset iteration condition is reached, and determine that the internal battery equalization adjustment of the current battery pack is completed.

[0087] In a specific application scenario, when repeatedly executing the first battery equalization processing procedure on the current battery pack based on the abnormal state value, the first processing module 33 can specifically be used to determine whether there is an abnormal single battery 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 battery in the current battery pack, then determine a first single battery and a second single battery in the current battery pack, and control the first single battery to supply electrical energy to the second single battery; repeatedly execute the above first battery equalization processing procedure until it is determined that a first preset iteration condition is met, where the first preset iteration condition is that the abnormal state values corresponding to all single batteries in the current battery pack are less than the first preset threshold, or the cumulative battery equalization duration reaches the maximum equalization duration.

[0088] In a specific application scenario, when repeatedly executing the second battery equalization processing procedure on the current battery pack based on the equalization adjustment characteristic value, the first processing module 33 can specifically be used to calculate the battery equalization adjustment parameter of the current battery pack based on the equalization adjustment characteristic value, and determine whether the battery equalization adjustment parameter is greater than a second preset threshold; if it is determined that the battery equalization adjustment parameter is greater than the second preset threshold, then determine a third single battery and a fourth single battery in the current battery pack, and control the third single battery to supply electrical energy to the fourth single battery; repeatedly execute the above second battery equalization processing procedure until it is determined that a second preset iteration condition is met, where 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 duration reaches the maximum equalization duration.

[0089] In a specific application scenario, when calculating the battery equalization adjustment parameter of the current battery pack based on the equalization adjustment characteristic value, the first processing module 33 can specifically be used to determine multiple equalization adjustment characteristic values corresponding to multiple single batteries in the current battery pack; extract the maximum equalization adjustment characteristic value and the minimum equalization adjustment characteristic value from the multiple equalization adjustment characteristic values; and determine the difference between the maximum equalization adjustment characteristic value and the minimum equalization adjustment characteristic value as the battery equalization adjustment parameter of the current battery pack.

[0090] In a specific application scenario, the second processing module 34 can be specifically used to repeatedly execute the third battery equalization processing procedure until it is determined that a third preset iteration condition is met. The third preset iteration condition is that the battery feature consistency between any two battery packs is greater than a third preset threshold, or the cumulative battery equalization duration reaches the maximum equalization duration. The third battery equalization processing procedure includes: calculating the average value of the equalization adjustment feature values of each battery pack based on the equalization adjustment feature values of each single battery within each battery pack; calculating the battery feature consistency between any two battery packs based on the average battery features and the average value of the equalization adjustment feature values of each battery pack; when it is determined that the battery feature consistency between any two battery packs is less than the third preset threshold, determining a first battery pack and a second battery pack within the multiple battery packs corresponding to the storage battery, and controlling the first battery pack to supply electrical energy to the second battery pack.

[0091] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated herein.

[0092] Based on the same inventive concept as the above method, an embodiment of the present invention further provides a storage battery state 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 one of the above storage battery state monitoring methods.

[0093] It should be noted that: the above sequence of embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. In addition, the above specific embodiments of this specification have been described. Moreover, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

[0095] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present invention shall be included in 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: Obtaining the capacitance change data and voltage change data of each single battery in each battery pack of the storage battery during discharge; Calculating the abnormal state value and the balance adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data; Based on the abnormal state value and the balance adjustment characteristic value, performing battery balance processing respectively within each of the battery packs; Calculating the battery characteristic consistency between the battery packs according to the balance adjustment characteristic value, and performing battery balance processing between the battery packs based on the battery characteristic consistency.

2. The battery state monitoring method according to claim 1, wherein The capacitance change data at least includes the remaining capacitance of the single battery at each discharge moment, the first capacitance of the single battery in the capacitance-time relationship curve at each discharge moment, and the second capacitance of the single battery in the voltage-capacitance relationship curve at each discharge moment. The voltage change data at least includes the voltage time-sequence change data of the single battery in the voltage-time relationship curve within a preset time period; Calculating the abnormal state value and the balance adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data includes: Calculating the first capacitance difference between the first capacitance and the remaining capacitance of each single battery, and the second capacitance difference between the second capacitance and the remaining capacitance; Based on the first capacitance difference, the second capacitance difference and the total capacitance of the single battery, calculating the abnormal state value of each single battery within each battery pack; Calculating the remaining capacity ratio of the remaining capacitance to the total capacitance of the single battery, and calculating the average voltage change slope of the single battery within the preset time period based on the voltage time-sequence change data; Based on the abnormal state value, the remaining capacity ratio and the average voltage change slope, calculating the balance adjustment characteristic value of each single battery within each battery pack.

3. The battery state monitoring method according to claim 2, characterized in that, Based on the abnormal state value, the remaining capacity ratio and the average voltage change slope, calculating the balance adjustment characteristic value of each single battery within each battery pack includes: Constructing the battery characteristic of each single battery within each battery pack according to the remaining capacity ratio and the average voltage change slope; Based on the battery characteristics of each single battery within each battery pack, calculating the average battery characteristic of each battery pack and the correlation coefficient between the voltage change and the capacitance change within each battery pack; Calculating the average abnormal state value of the multiple abnormal state values corresponding to the multiple single batteries within each battery pack; Using the battery characteristic, the average battery characteristic, the correlation coefficient, the abnormal state value and the average abnormal state value, calculating the balance adjustment characteristic value of each single battery within each battery pack.

4. The battery state monitoring method according to claim 1, wherein Based on the abnormal state value and the balance adjustment characteristic value, performing battery balance processing respectively within each of the battery packs includes: Sequentially determine each of the battery packs as the current battery pack, 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 reaches the first preset iteration condition, continue to repeatedly execute the second battery equalization process on the current battery pack based on the equalization adjustment characteristic value until the second preset iteration condition is reached, and determine that the internal battery equalization adjustment of the current battery pack is completed.

5. The battery state monitoring method according to claim 4, wherein Repeatedly executing the first battery equalization process on the current battery pack based on the abnormal state value includes: Determine whether there is an abnormal single battery in the current battery pack whose corresponding abnormal state value is greater than the first preset threshold; If it is determined that there is the abnormal single battery in the current battery pack, determine a first single battery and a second single battery in the current battery pack, and control the first single battery to supply electrical energy to the second single battery; Repeatedly execute the above first battery equalization process until it is determined that the first preset iteration condition is reached. The first preset iteration condition is that the abnormal state values corresponding to all single batteries in the current battery pack are less than the first preset threshold, or the cumulative battery equalization duration reaches the maximum equalization duration.

6. The battery state monitoring method according to claim 4, wherein Continuing to repeatedly execute the second battery equalization process on the current battery pack based on the equalization adjustment characteristic value includes: Calculate the battery equalization adjustment parameter of the current battery pack based on the equalization adjustment characteristic value, and determine whether the battery equalization adjustment parameter is greater than the second preset threshold; If it is determined that the battery equalization adjustment parameter is greater than the second preset threshold, determine a third single battery and a fourth single battery in the current battery pack, and control the third single battery to supply electrical energy to the fourth single battery; Repeatedly execute the above second battery equalization process until it is determined that the second preset iteration condition is reached. 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 duration reaches the maximum equalization duration.

7. The battery state monitoring method according to claim 6, characterized in that, Calculating the battery equalization adjustment parameter of the current battery pack based on the equalization adjustment characteristic value includes: Determine multiple equalization adjustment characteristic values corresponding to multiple single batteries in the current battery pack; Extract the maximum equalization adjustment characteristic value and the minimum equalization adjustment characteristic value from the multiple equalization adjustment characteristic values; Determine the difference between the maximum equalization adjustment characteristic value and the minimum equalization adjustment characteristic value as the battery equalization adjustment parameter of the current battery pack.

8. The battery state monitoring method according to claim 3, characterized in that Calculating the battery characteristic consistency between each battery pack according to the equalization adjustment characteristic value, and performing battery equalization processing between each battery pack based on the battery characteristic consistency includes: Repeatedly execute the third battery equalization process until it is determined that the third preset iteration condition is reached. The third preset iteration condition is that the battery characteristic consistency between any two battery packs is greater than the third preset threshold, or the cumulative battery equalization duration reaches the maximum equalization duration; Among them, the third battery equalization process includes: Calculate the average value of the balancing adjustment characteristic values of each battery pack based on the balancing adjustment characteristic values of each single battery in each battery pack. Calculate the battery characteristic consistency between any two battery packs based on the average battery characteristics of each battery pack and the average value of the balancing adjustment characteristic values. When it is determined that the battery characteristic consistency between any two battery packs is less than the third preset threshold, determine the first battery pack and the second battery pack in the multiple battery packs corresponding to the storage battery, and control the first battery pack to supply electrical energy to the second battery pack.

9. A battery state monitoring device, characterized in that, Including: An acquisition module for acquiring the capacitance change data and voltage change data of each single battery in each battery pack of the storage battery during discharge. A calculation module for calculating the abnormal state value and the balancing adjustment characteristic value of each single battery according to the capacitance change data and the voltage change data. A first processing module for performing battery balancing processing respectively within each battery pack based on the abnormal state value and the balancing adjustment characteristic value. A second processing module for calculating the battery characteristic consistency between each battery pack according to the balancing adjustment characteristic value and performing battery balancing processing between each battery pack based on the battery characteristic consistency.

10. A battery state monitoring system, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the computer program is executed by a processor, it implements the steps of a method for monitoring the state of a storage battery according to any one of claims 1 to 8.

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