Battery cluster health online monitoring method and related device

Abstract

The present invention relates to the field of energy storage. The present invention discloses a method and related device for online monitoring of the health of a battery cluster. The method obtains the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of a first battery cell, and the operating current of the first battery cell from a battery management system; calculates the conversion energy of the battery cluster based on the operating voltage and the operating current of the battery cluster; calculates the conversion energy of the first battery cell based on the operating voltage and the operating current of the first battery cell; and determines the inconsistency of the battery cell of the battery cluster based on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first battery cell. The present invention can accurately judge the inconsistency of the battery cell of a battery cluster online based on data in the battery management system, and the calculation results are relatively accurate and timely.

Description

Technical Field

[0001] The present invention relates to the field of energy storage, and in particular to a method and related device for online monitoring of the health of a battery cluster. Background Art

[0002] Lithium-ion batteries inevitably exhibit variations during the manufacturing process. These variations increase with age and operating conditions, leading to overcharge or over-discharge of cells within a battery cluster, posing safety risks. Therefore, timely and accurate battery cluster health monitoring has become a pressing technical challenge facing researchers in this field. Summary of the Invention

[0003] In view of the above problems, the present invention provides a method for online monitoring the health of a battery cluster and a related device that overcomes the above problems or at least partially solves the above problems.

[0004] In a first aspect, a method for online monitoring of battery cluster health includes:

[0005] Obtaining from a battery management system an operating voltage of a battery cluster, an operating current of the battery cluster, an operating voltage of a first battery cell, and an operating current of the first battery cell, wherein the operating voltage is a voltage during a charging process or a discharging process, the operating current is a current during a charging process or a discharging process, and the first battery cell is one of the battery cells included in the battery cluster;

[0006] Calculating the conversion energy of the battery cluster according to the operating voltage and the operating current of the battery cluster, wherein the conversion energy of the battery cluster is the charging energy of the battery cluster during the charging process or the discharging energy of the battery cluster during the discharging process;

[0007] Calculating the conversion energy of the first battery cell according to the operating voltage of the first battery cell and the operating current of the first battery cell, wherein the conversion energy of the first battery cell is the charging energy of the first battery cell during the charging process or the discharging energy of the first battery cell during the discharging process;

[0008] The cell inconsistency of the battery cluster is determined according to the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells, wherein the cell inconsistency represents the degree of inconsistency of the performance of each single cell of the battery cluster.

[0009] Optionally, in certain optional embodiments, before obtaining the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of the first battery cell, and the operating current of the first battery cell from the battery management system, the method further includes:

[0010] If the battery cluster is a battery cluster whose operating time is less than a preset operating threshold, selecting a single cell that meets a first condition from each single cell included in the battery cluster as the first single cell, wherein the first condition is: the voltage of the single cell is closest to the average voltage of all the single cells in the battery cluster and the capacity of the single cell is closest to the average capacity of all the single cells in the battery cluster;

[0011] If the battery cluster has an operating time greater than the preset operating threshold, a single cell that meets a second condition is selected from the single cells included in the battery cluster as the first single cell, wherein the second condition is: the temperature of the single cell is closest to the average temperature of all the single cells in the battery cluster.

[0012] Optionally, in certain optional embodiments, calculating the conversion energy of the battery cluster according to the operating voltage and the operating current of the battery cluster includes:

[0013] calculating a first product of an operating voltage of the battery cluster and an operating current of the battery cluster;

[0014] A definite integral is calculated on the first product to obtain the conversion energy of the battery cluster, wherein an upper limit of the integral of the definite integral is a duration of a charging process or a discharging process of the battery cluster.

[0015] Optionally, in some optional embodiments, calculating the conversion energy of the first single battery cell according to the operating voltage of the first single battery cell and the operating current of the first single battery cell includes:

[0016] Calculating a second product of the operating voltage of the first battery cell and the operating current of the first battery cell;

[0017] A definite integral is calculated on the second product to obtain the conversion energy of the first single battery cell, wherein an upper limit of the integral of the definite integral is a duration of a charging process or a discharging process of the first single battery cell.

[0018] Optionally, in certain optional embodiments, determining the inconsistency of the single cells of the battery cluster according to the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells includes:

[0019] Performing linear fitting on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single battery cell and performing derivative thereof to obtain a first slope;

[0020] If the first slope increases, it is determined that the inconsistency of the single cells of the battery cluster is aggravated;

[0021] If the first slope remains stable, it is determined that the inconsistency of the single cells of the battery cluster is stable.

[0022] Optionally, in some optional embodiments, the method further comprises:

[0023] Recording the charge energy and discharge energy of the battery cluster over multiple charge and discharge cycles, wherein one charge and discharge cycle corresponds to one charge energy and one discharge energy, the charge start SOC and the discharge end SOC of one charge and discharge cycle are consistent, the charge start SOC of different charge and discharge cycles are consistent, and the discharge end SOC of different charge and discharge cycles are consistent;

[0024] For any of the charge and discharge cycles, calculating the energy difference between the charge energy and the discharge energy of the battery cluster during the charge and discharge cycle to obtain the energy change of the battery cluster during the charge and discharge cycle;

[0025] Accumulating the energy changes of each charge and discharge cycle in sequence, accumulating the energy changes of one more charge and discharge cycle each time, and obtaining a corresponding accumulated energy change each time;

[0026] Fitting each of the accumulated change energies with the corresponding accumulated number of charge and discharge cycles and taking the derivative to obtain a second slope;

[0027] If the second slope increases, determining that the energy efficiency of the battery cluster decreases;

[0028] If the second slope remains stable, it is determined that the energy efficiency of the battery cluster remains stable.

[0029] In a second aspect, a battery cluster health online monitoring device includes: a data acquisition unit, a battery cluster calculation unit, a single cell calculation unit, and an inconsistency determination unit;

[0030] The data acquisition unit is configured to obtain, from a battery management system, an operating voltage of a battery cluster, an operating current of the battery cluster, an operating voltage of a first battery cell, and an operating current of the first battery cell, wherein the operating voltage is a voltage during a charging process or a discharging process, the operating current is a current during a charging process or a discharging process, and the first battery cell is one of the battery cells included in the battery cluster;

[0031] The battery cluster calculation unit is configured to calculate the conversion energy of the battery cluster based on the operating voltage and the operating current of the battery cluster, wherein the conversion energy of the battery cluster is the charging energy of the battery cluster during the charging process or the discharging energy of the battery cluster during the discharging process;

[0032] The single cell calculation unit is configured to calculate the conversion energy of the first single cell according to the operating voltage and the operating current of the first single cell, wherein the conversion energy of the first single cell is the charging energy of the first single cell during the charging process or the discharging energy of the first single cell during the discharging process;

[0033] The inconsistency determining unit is configured to determine the single cell inconsistency of the battery cluster based on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells, wherein the cell inconsistency represents the degree of inconsistency in the performance of each single cell of the battery cluster.

[0034] Optionally, in certain optional embodiments, the apparatus further comprises: a first selection unit and a second selection unit;

[0035] The first selection unit is configured to, before obtaining the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of the first single cell, and the operating current of the first single cell from the battery management system, if the battery cluster is a battery cluster whose operating time is less than a preset operating threshold, select a single cell that meets a first condition from each single cell included in the battery cluster as the first single cell, wherein the first condition is: the voltage of the single cell is closest to the average voltage of all the single cells of the battery cluster and the capacity of the single cell is closest to the average capacity of all the single cells of the battery cluster;

[0036] The second selection unit is configured to select, if the battery cluster has an operating time greater than the preset operating threshold, a single cell that satisfies a second condition from the single cells included in the battery cluster as the first single cell, wherein the second condition is that the temperature of the single cell is closest to the average temperature of all the single cells in the battery cluster.

[0037] In a third aspect, a computer-readable storage medium stores a program, wherein when the program is executed by a processor, the method for online monitoring of battery cluster health as described above is implemented.

[0038] In a fourth aspect, an electronic device includes at least one processor, and at least one memory and a bus connected to the processor; wherein the processor and the memory communicate with each other via the bus; and the processor is configured to call program instructions in the memory to execute any of the above-described methods for online monitoring of battery cluster health.

[0039] By means of the above technical solution, the present invention provides a method and related device for online monitoring of the health of a battery cluster, which can obtain the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of the first single cell and the operating current of the first single cell from the battery management system, wherein the operating voltage is the voltage during the charging process or the discharging process, the operating current is the current during the charging process or the discharging process, and the first single cell is a single cell among the single cells included in the battery cluster; according to the operating voltage of the battery cluster and the operating current of the battery cluster, the conversion energy of the battery cluster is calculated, wherein the The conversion energy of a battery cluster is the charging energy of the battery cluster during the charging process or the discharging energy during the discharging process; the conversion energy of the first single cell is calculated based on the operating voltage of the first single cell and the operating current of the first single cell, wherein the conversion energy of the first single cell is the charging energy of the first single cell during the charging process or the discharging energy of the first single cell during the discharging process; the cell inconsistency of the battery cluster is determined based on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cell, wherein the cell inconsistency characterizes the degree of inconsistency in the performance of each cell of the battery cluster. It can be seen from this that the present invention can accurately judge the cell inconsistency of a battery cluster online based on data in a battery management system, and the calculation results are relatively accurate and timely.

[0040] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0042] Figure 1 A flowchart of a first method for online monitoring of battery cluster health provided by the present invention is shown;

[0043] Figure 2 A schematic diagram of a scatter plot provided by the present invention is shown;

[0044] Figure 3 A flow chart of a second method for online monitoring of battery cluster health provided by the present invention is shown;

[0045] Figure 4A schematic structural diagram of an online monitoring device for the health of a battery cluster provided by the present invention is shown;

[0046] Figure 5 A schematic structural diagram of an electronic device provided by the present invention is shown. DETAILED DESCRIPTION

[0047] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0048] like Figure 1 As shown, the present invention provides a method for online monitoring of battery cluster health, including: S100, S200, S300 and S400;

[0049] S100: Obtaining, from a battery management system, an operating voltage of a battery cluster, an operating current of the battery cluster, an operating voltage of a first battery cell, and an operating current of the first battery cell, wherein the operating voltage is a voltage during a charging process or a discharging process, the operating current is a current during a charging process or a discharging process, and the first battery cell is one of the battery cells included in the battery cluster;

[0050] Optionally, to boost the battery pack voltage, energy storage stations connect multiple batteries in series to form battery clusters. A battery cluster often consists of hundreds of batteries (also called single cells). Due to the series connection and the inconsistency between the batteries, batteries in the same cluster have the same current but different voltages during operation. If there is no inconsistency between the batteries, the voltages of batteries in the same cluster are exactly the same during operation.

[0051] Optionally, the battery management system described in the present invention can monitor the operating conditions of the battery cluster and its individual cells, including charging voltage, charging current, discharge voltage, and discharge current. Therefore, the present invention can directly obtain corresponding parameters from the battery management system based on actual needs, and the present invention is not limited to this.

[0052] Optionally, when the battery cluster is charging, the present invention can obtain the charging voltage of the battery cluster, the charging current of the battery cluster, the charging voltage of the single cell and the charging current of the single cell; when the battery cluster is discharging, the present invention can obtain the discharge voltage of the battery cluster, the discharge current of the battery cluster, the discharge voltage of the single cell and the discharge current of the single cell, and the present invention does not impose any restrictions on this.

[0053] Optionally, the operating parameters (voltage and current) of the battery cluster and the operating parameters (voltage and current) of the battery cells must be the same during the same charging phase or the same discharging phase. The battery management system can record this information. For example, to obtain the charging voltage and current of the battery cluster from 10:00 to 14:00, the charging voltage and current of the individual battery cells from the same period must also be obtained.

[0054] Optionally, as previously mentioned, due to inconsistencies between series connections and batteries, batteries in the same cluster may have the same current but different voltages during operation. Therefore, to determine the inconsistency between individual cells in a battery cluster, the present invention can select a single cell from the battery cluster and compare the operating parameters of the single cell with the operating parameters of the battery cluster to determine the inconsistency between the individual cells in the battery cluster.

[0055] That is, in some optional embodiments, before S100, the method further includes: step 1.1 and step 1.2;

[0056] Step 1.1: If the battery cluster has an operating time less than a preset operating threshold, select a single cell that satisfies a first condition from the single cells included in the battery cluster as the first single cell, wherein the first condition is: the voltage of the single cell is closest to the average voltage of all the single cells in the battery cluster and the capacity of the single cell is closest to the average capacity of all the single cells in the battery cluster;

[0057] Alternatively, for a battery cluster whose operating time is less than a preset operating threshold, this indicates that it has not been in operation for a long time and that the battery cells have not undergone significant changes. Therefore, the present invention can select the first battery cell based on the first condition. Specifically, the battery cell in the battery cluster that meets the first condition is selected as the first battery cell.

[0058] Optionally, the first condition is as shown in Formula 1, where u k and q k They represent the voltage and capacity of the first single cell respectively; i is the number of the single cell, ranging from 1 to n; n is the number of single cells included in the battery cluster; u i is the voltage of the i-th single cell; q i is the capacity of the ith single cell, which is not limited in the present invention. Formula 1:

[0059] Step 1.2: If the battery cluster has been in operation for a period of time greater than the preset operating threshold, it indicates that it has been in operation for a long time and the battery cells may have undergone significant changes. Therefore, the present invention can select a single cell from the battery cluster that meets a second condition as the first single cell, wherein the second condition is that the temperature of the single cell is closest to the average temperature of all the single cells in the battery cluster.

[0060] Optionally, because battery aging is strongly correlated with ambient temperature, the present invention can select the first battery cell based on the second condition for battery clusters that have been operating for a certain period of time. Based on the second condition, the present invention can dynamically select the first battery cell based on a certain period, for example, reselecting the first battery cell based on the second condition every month, which provides more accurate results.

[0061] Optionally, the second condition is as shown in Formula 2, where t k is the temperature of the first single cell; t i is the temperature of the i-th single cell; i is the number of the single cell, ranging from 1 to n; n is the number of single cells included in the battery cluster. Formula 2:

[0062] S200: Calculate conversion energy of the battery cluster based on the operating voltage and the operating current of the battery cluster, wherein the conversion energy of the battery cluster is the charging energy of the battery cluster during a charging process or the discharging energy of the battery cluster during a discharging process;

[0063] Optionally, if the operating voltage and operating current obtained in S100 are obtained during the charging process, that is, the operating voltage is the charging voltage and the operating current is the charging current, then the present invention can calculate the charging energy of the charging process based on the operating voltage and the operating current. Similarly, if the operating voltage and operating current obtained in S100 are obtained during the discharging process, that is, the operating voltage is the discharging voltage and the operating current is the discharging current, then the present invention can calculate the discharge energy of the discharging process based on the operating voltage and the operating current. The present invention is not limited to this.

[0064] That is, in some optional embodiments, the S200 includes: step 2.1 and step 2.2;

[0065] Step 2.1, calculating a first product of the operating voltage of the battery cluster and the operating current of the battery cluster;

[0066] Step 2.2: Perform definite integral calculation on the first product to obtain the conversion energy of the battery cluster, wherein the upper limit of the integral of the definite integral is the duration of the charging process or the discharging process of the battery cluster.

[0067] Optionally, the execution process of step 2.1 and step 2.2 is shown in Formula 3, where E is the conversion energy of the battery cluster, U(t) is the operating voltage of the battery cluster, I(t) is the operating current of the battery cluster, and t is the duration of the charging process or discharging process of the battery cluster (if the charging voltage and charging current are used, it corresponds to the duration of the charging process; if the discharging voltage and discharging current are used, it corresponds to the duration of the discharging process). Formula 3:

[0068] S300: Calculate the conversion energy of the first battery cell according to the operating voltage and the operating current of the first battery cell, wherein the conversion energy of the first battery cell is the charging energy of the first battery cell during the charging process or the discharging energy of the first battery cell during the discharging process;

[0069] For example, in some optional embodiments, the S300 includes: step 3.1 and step 3.2;

[0070] Step 3.1, calculating a second product of the operating voltage of the first battery cell and the operating current of the first battery cell;

[0071] Step 3.2: Perform definite integral calculation on the second product to obtain the conversion energy of the first single battery cell, wherein the upper limit of the integral of the definite integral is the duration of the charging process or the discharging process of the first single battery cell.

[0072] Optionally, the execution process of step 3.1 and step 3.2 is shown in formula 4, where e i is the conversion energy of the first single cell, u i (t) is the operating voltage of the first battery cell, I(t) is the operating current of the first battery cell, and t is the duration of the charging process or discharging process of the first battery cell (if the charging voltage and charging current are used, it corresponds to the duration of the charging process; if the discharging voltage and discharging current are used, it corresponds to the duration of the discharging process). Formula 4:

[0073]

[0074] S400 : Determine inconsistency of single cells of the battery cluster according to multiple conversion energies of the battery cluster and multiple conversion energies of the first single cells, wherein the cell inconsistency represents a degree of inconsistency in performance of each single cell of the battery cluster.

[0075] Optionally, combining the above formula 3 and formula 4, since the single cells are connected in series, in the initial operation or under ideal conditions, the inconsistency between the single cells is relatively small, and the relationship shown in formula 5 exists. Formula 5: Based on Formula 5, the operating parameters of the battery cluster and the first single cell are monitored in real time, and a linear fitting is performed to obtain the functional relationship f(n×e i )=E, the rate of change of the linear relationship can reflect the inconsistency of the battery cluster.

[0076] For example, in some optional embodiments, the S400 includes: step 4.1, step 4.2 and step 4.3;

[0077] Step 4.1, performing linear fitting on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single battery cell and performing derivative thereof to obtain a first slope;

[0078] Optionally, the present invention can calculate multiple conversion energies of the battery cluster and multiple conversion energies of the first single cell at different times. That is, the conversion energy of the battery cluster and the conversion energy of the first single cell are calculated at each time, thereby obtaining the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cell. The present invention is not limited to this.

[0079] Step 4.2: If the first slope increases, it is determined that the inconsistency of the single cells of the battery cluster is aggravated;

[0080] Step 4.3: If the first slope remains stable, it is determined that the inconsistency of the single cells of the battery cluster is stable.

[0081] Optionally, in addition to determining the inconsistency of the single cells of the battery cluster, the present invention can also determine the energy efficiency of the battery cluster. The energy efficiency can also reflect the health of the battery cluster to a certain extent, and the present invention does not impose any limitation on this.

[0082] That is, in certain optional embodiments, the method further comprises: step 5.1, step 5.2, step 5.3, step 5.4, step 5.5 and step 5.6;

[0083] Step 5.1, recording the charge energy and discharge energy of the battery cluster in multiple charge and discharge cycles, wherein one charge and discharge cycle corresponds to one charge energy and one discharge energy, the charge start SOC and the discharge end SOC of one charge and discharge cycle are consistent, the charge start SOC of different charge and discharge cycles are consistent, and the discharge end SOC of different charge and discharge cycles are consistent;

[0084] Optionally, with respect to the understanding of the charge and discharge cycle, it is generally believed that from the start of the current charging of the battery cluster to the next charging of the battery cluster, it can be understood as a charge and discharge cycle. In the field of energy storage, once charging begins, it will generally continue until the requirements are met before stopping, and then discharge will be carried out according to the plan, but the discharge process can be one or more times. That is, a charge and discharge cycle generally includes one charging process and at least one discharging process. For example, a battery cluster starts charging from an SOC of 20%, and starts discharging when it is charged to 90%. After at least one discharge, the SOC drops back to 20% (or around 20%). The entire process can be understood as a charge and discharge cycle, and the present invention does not impose any restrictions on this. SOC refers to the state of charge, which is an indicator used to quantify the remaining capacity of the battery.

[0085] In combination with the above explanation, the battery cluster starts charging from an SOC of 20%. The 20% SOC at this time can be understood as the charging starting SOC mentioned in this article; the SOC drops back to 20% (or near 20%). The 20% SOC at this time (or near 20%) can be understood as the discharge cut-off SOC, which is not limited in the present invention.

[0086] Optionally, in order to ensure the accuracy of the present invention, it is generally required that the charging starting SOC of each charging and discharging cycle is the same (for example, charging starts from 20%), and the discharge ending SOC of each charging and discharging cycle is also the same (for example, discharging drops to 20% or near 20%). The present invention does not impose any restrictions on this.

[0087] Step 5.2: for any of the charge and discharge cycles, calculating the energy difference between the charge energy and the discharge energy of the battery cluster during the charge and discharge cycle, to obtain the energy change of the battery cluster during the charge and discharge cycle;

[0088] Optionally, in each charge and discharge cycle, the present invention may record the charge energy and discharge energy of the battery cluster and then use them to calculate the energy difference, which is not limited in the present invention.

[0089] Optionally, the charging energy is shown in Formula 6, and the discharging energy is shown in Formula 7. Formula 6: Formula 7: The present invention is not limited to this.

[0090] Optionally, the energy difference calculation process is shown in Formula 8. Formula 8: E d =E 充 -E 放 . It can be seen from this that E d The smaller the value, the smaller the energy loss and the higher the energy efficiency of the battery cluster. The present invention does not impose any limitation on this.

[0091] Step 5.3, accumulating the energy changes of each charge and discharge cycle in sequence, accumulating the energy changes of one more charge and discharge cycle each time, and obtaining a corresponding accumulated energy change each time;

[0092] Step 5.4, fitting each of the accumulated change energies with the corresponding accumulated number of charge and discharge cycles and taking the derivative to obtain a second slope;

[0093] Step 5.5: If the second slope increases, determining that the energy efficiency of the battery cluster decreases;

[0094] Step 5.6: If the second slope remains stable, it is determined that the energy efficiency of the battery cluster remains stable.

[0095] Optionally, the energy storage station of the present invention charges during low-peak electricity consumption, charging the SOC from a to b, and discharges during peak electricity consumption. There may be multiple discharges, eventually reducing the SOC from b to c (c is generally equal to or close to a), and so on. The energy difference E of each cycle is calculated as d Accumulate and set the value to E sum The number of cycles m and E sum The combined feature points (m, E sum ), for the function f(m,E sum ) to perform linear fitting, obtain the second slope, and draw a schematic scatter plot as follows Figure 2 shown.

[0096] Optionally, due to the existence of losses, if the start and end SOC of a charge and discharge cycle are the same, then E 充 >E 放 , that is, E d Greater than 0. E sum The value of will increase linearly as the cycle progresses. As the charge and discharge cycles progress, the changes in the second slope are recorded. If the second slope remains stable, it indicates that the battery cluster is in good health; if the second slope increases, it indicates that the energy efficiency has decreased.

[0097] Optionally, when there is an abnormal working condition, assuming that the SOC is charged from 10% to 90% and discharged from 90% to 50% in one cycle, the E d Larger, from the scatter plot, E sum In the next charge and discharge cycle, since the initial SOC is 50%, E d is a negative number, E sum The peak value will drop, which will cause the scatter plot to show a sharp peak and an extreme point. The extreme point does not affect the second slope as a whole. That is, the calculation of the second slope is not affected by abnormal working conditions. The abnormal working conditions can be quickly identified from the peak of the scatter plot, for example, Figure 2The peak in the.

[0098] Alternatively, the normal operating condition described above refers to the energy storage station charging and discharging according to plan, for example, charging from 4% SOC to 96% SOC, then discharging to 4% SOC, and repeating this cycle. This typically involves one charge followed by multiple discharges. In other words, under normal circumstances, the battery SOC fluctuates from 4% to 96% to 4% over a cycle. Because of battery wear, even though the starting and ending SOCs within a cycle are the same, the charge capacity is always greater than the discharge capacity. An abnormal operating condition involves, for example, charging from 4% to 96%, but discharging from 96% to 50%, and then starting the next charge cycle at 50%. Therefore, over this cycle, the battery SOC varies from 4% to 96% to 50%. This means that the battery's charge capacity is significantly greater than its discharge capacity, causing the accumulated energy difference to suddenly increase. This would appear as a bump on a graph. In the next cycle, the battery's capacity changes from 50% to 96% to 4%. Clearly, the battery's charge capacity is much smaller than its discharge capacity, resulting in a negative energy difference and a decreasing cumulative value. This is reflected on the graph as a dip, followed by an up-and-down pattern, forming a sharp peak that is easy to observe. Abnormal operating conditions don't necessarily indicate a battery problem; rather, they can help power station personnel monitor battery operation, such as whether a battery has unexpectedly stopped discharging.

[0099] Optionally, in order to further clearly describe the solution of the present invention, the present invention provides the following Figure 3 The flowchart shown, Figure 3 Please refer to the above explanation for the content, which will not be elaborated in this article.

[0100] In summary, the present invention can accurately determine the inconsistency of individual cells in a battery cluster online based on data from the battery management system, providing relatively accurate and timely calculation results. Data can be directly acquired from the battery management system, without the need for additional equipment. The required data volume is minimal, requiring only the data for the first individual cell and the battery cluster.

[0101] like Figure 4 As shown, the present invention provides a battery cluster health online monitoring device, comprising: a data acquisition unit 100, a battery cluster calculation unit 200, a single cell calculation unit 300 and an inconsistency determination unit 400;

[0102] The data acquisition unit 100 is configured to obtain, from a battery management system, an operating voltage of a battery cluster, an operating current of the battery cluster, an operating voltage of a first battery cell, and an operating current of the first battery cell, wherein the operating voltage is a voltage during a charging process or a discharging process, the operating current is a current during a charging process or a discharging process, and the first battery cell is one of the battery cells included in the battery cluster;

[0103] The battery cluster calculation unit 200 is configured to calculate the conversion energy of the battery cluster based on the operating voltage and the operating current of the battery cluster, wherein the conversion energy of the battery cluster is the charging energy of the battery cluster during the charging process or the discharging energy of the battery cluster during the discharging process;

[0104] The single cell calculation unit 300 is configured to calculate the conversion energy of the first single cell according to the operating voltage and the operating current of the first single cell, wherein the conversion energy of the first single cell is the charging energy of the first single cell during the charging process or the discharging energy of the first single cell during the discharging process;

[0105] The inconsistency determining unit 400 is configured to determine the single cell inconsistency of the battery cluster based on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells, wherein the cell inconsistency represents the degree of inconsistency in the performance of each single cell of the battery cluster.

[0106] Optionally, in certain optional embodiments, the apparatus further comprises: a first selection unit and a second selection unit;

[0107] The first selection unit is configured to, before obtaining the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of the first single cell, and the operating current of the first single cell from the battery management system, if the battery cluster is a battery cluster whose operating time is less than a preset operating threshold, select a single cell that meets a first condition from each single cell included in the battery cluster as the first single cell, wherein the first condition is: the voltage of the single cell is closest to the average voltage of all the single cells of the battery cluster and the capacity of the single cell is closest to the average capacity of all the single cells of the battery cluster;

[0108] The second selection unit is configured to select, if the battery cluster has an operating time greater than the preset operating threshold, a single cell that satisfies a second condition from the single cells included in the battery cluster as the first single cell, wherein the second condition is that the temperature of the single cell is closest to the average temperature of all the single cells in the battery cluster.

[0109] Optionally, in some optional embodiments, the battery cluster calculation unit 200 includes: a first multiplication unit and a first integration unit;

[0110] The first product unit is used to calculate a first product of the operating voltage of the battery cluster and the operating current of the battery cluster;

[0111] The first integration unit is configured to perform definite integral calculation on the first product to obtain the conversion energy of the battery cluster, wherein an upper limit of the definite integral is a duration of a charging process or a discharging process of the battery cluster.

[0112] Optionally, in some optional embodiments, the single cell calculation unit 300 includes: a second multiplication unit and a second integration unit;

[0113] The second product unit is used to calculate a second product of the operating voltage of the first single battery cell and the operating current of the first single battery cell;

[0114] The second integrating unit is configured to perform definite integral calculation on the second product to obtain the conversion energy of the first single battery cell, wherein an upper limit of the definite integral is a duration of a charging process or a discharging process of the first single battery cell.

[0115] Optionally, in some optional implementations, the inconsistency determination unit 400 includes: a first slope unit, a first result unit, and a second result unit;

[0116] The first slope unit is configured to perform linear fitting and derivative on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single battery cells to obtain a first slope;

[0117] The first result unit is configured to determine that the inconsistency of the single cells of the battery cluster is aggravated if the first slope increases;

[0118] The second result unit is configured to determine that the inconsistency of the single cells of the battery cluster is stable if the first slope remains stable.

[0119] Optionally, in certain optional embodiments, the device further comprises: an energy recording unit, an energy difference calculation unit, an energy accumulation unit, a second slope unit, a third result unit, and a fourth result unit;

[0120] The energy recording unit is used to record the charging energy and discharging energy of the battery cluster during multiple charging and discharging cycles, wherein one charging and discharging cycle corresponds to one charging energy and one discharging energy, the charging start SOC and the discharging end SOC of one charging and discharging cycle are consistent, the charging start SOC of different charging and discharging cycles are consistent, and the discharging end SOC of different charging and discharging cycles are consistent;

[0121] The energy difference calculation unit is configured to calculate, for any of the charge and discharge cycles, an energy difference between the charge energy and the discharge energy of the battery cluster during the charge and discharge cycle, to obtain an energy change of the battery cluster during the charge and discharge cycle;

[0122] The energy accumulation unit is used to accumulate the energy changes of each charge and discharge cycle in sequence, accumulating the energy changes of one more charge and discharge cycle each time, and each accumulation obtains a corresponding accumulated change energy;

[0123] The second slope unit is configured to fit and derive each of the accumulated change energies and the corresponding accumulated number of charge and discharge cycles to obtain a second slope;

[0124] The third result unit is configured to determine that the energy efficiency of the battery cluster decreases if the second slope increases;

[0125] The fourth result unit is configured to determine that the energy efficiency of the battery cluster remains stable if the second slope remains stable.

[0126] The present invention provides a computer-readable storage medium having a program stored thereon, wherein when the program is executed by a processor, the method for online monitoring of the health of a battery cluster described above is implemented.

[0127] like Figure 5 As shown, the present invention provides an electronic device 70, which includes at least one processor 701, and at least one memory 702 and a bus 703 connected to the processor 701. The processor 701 and the memory 702 communicate with each other via the bus 703. The processor 701 is configured to call program instructions in the memory 702 to execute any of the above-mentioned methods for online monitoring of battery cluster health.

[0128] In the present invention, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0129] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0130] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to be embodied in the widest possible manner consistent with the principles and novel features disclosed herein.

[0131] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A method for online monitoring of battery cluster health, characterized in that: include: Obtaining from a battery management system an operating voltage of a battery cluster, an operating current of the battery cluster, an operating voltage of a first battery cell, and an operating current of the first battery cell, wherein the operating voltage is a voltage during a charging process or a discharging process, the operating current is a current during a charging process or a discharging process, and the first battery cell is one of the battery cells included in the battery cluster; Calculating the conversion energy of the battery cluster according to the operating voltage and the operating current of the battery cluster, wherein the conversion energy of the battery cluster is the charging energy of the battery cluster during the charging process or the discharging energy of the battery cluster during the discharging process; Calculating the conversion energy of the first battery cell according to the operating voltage of the first battery cell and the operating current of the first battery cell, wherein the conversion energy of the first battery cell is the charging energy of the first battery cell during the charging process or the discharging energy of the first battery cell during the discharging process; determining, based on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single battery cell, a single battery cell inconsistency of the battery cluster, wherein the single battery cell inconsistency represents a degree of inconsistency in performance of each single battery cell of the battery cluster; The determining of the inconsistency of the single cells of the battery cluster according to the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells includes: Performing linear fitting on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single battery cell and performing derivative thereof to obtain a first slope; If the first slope increases, it is determined that the inconsistency of the single cells of the battery cluster is aggravated; If the first slope remains stable, it is determined that the inconsistency of the single cells of the battery cluster is stable.

2. The method according to claim 1, characterized in that Before obtaining the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of the first battery cell, and the operating current of the first battery cell from the battery management system, the method further includes: If the battery cluster is a battery cluster whose operating time is less than a preset operating threshold, selecting a single cell that meets a first condition from each single cell included in the battery cluster as the first single cell, wherein the first condition is: the voltage of the single cell is closest to the average voltage of all the single cells in the battery cluster and the capacity of the single cell is closest to the average capacity of all the single cells in the battery cluster; If the battery cluster has an operating time greater than the preset operating threshold, a single cell that meets a second condition is selected from the single cells included in the battery cluster as the first single cell, wherein the second condition is: the temperature of the single cell is closest to the average temperature of all the single cells in the battery cluster.

3. The method according to claim 1, characterized in that The calculating and obtaining the conversion energy of the battery cluster according to the operating voltage and the operating current of the battery cluster includes: calculating a first product of an operating voltage of the battery cluster and an operating current of the battery cluster; A definite integral is calculated on the first product to obtain the conversion energy of the battery cluster, wherein an upper limit of the integral of the definite integral is a duration of a charging process or a discharging process of the battery cluster.

4. The method according to claim 1, wherein The calculating the conversion energy of the first battery cell according to the operating voltage of the first battery cell and the operating current of the first battery cell includes: Calculating a second product of the operating voltage of the first battery cell and the operating current of the first battery cell; A definite integral is calculated on the second product to obtain the conversion energy of the first single battery cell, wherein an upper limit of the integral of the definite integral is a duration of a charging process or a discharging process of the first single battery cell.

5. The method according to claim 1, wherein The method further comprises: Recording the charge energy and discharge energy of the battery cluster over multiple charge and discharge cycles, wherein one charge and discharge cycle corresponds to one charge energy and one discharge energy, the charge start SOC and the discharge end SOC of one charge and discharge cycle are consistent, the charge start SOC of different charge and discharge cycles are consistent, and the discharge end SOC of different charge and discharge cycles are consistent; For any of the charge and discharge cycles, calculating the energy difference between the charge energy and the discharge energy of the battery cluster during the charge and discharge cycle to obtain the energy change of the battery cluster during the charge and discharge cycle; Accumulating the energy changes of each charge and discharge cycle in sequence, accumulating the energy changes of one more charge and discharge cycle each time, and obtaining a corresponding accumulated energy change each time; Fitting each of the accumulated change energies with the corresponding accumulated number of charge and discharge cycles and taking the derivative to obtain a second slope; If the second slope increases, determining that the energy efficiency of the battery cluster decreases; If the second slope remains stable, it is determined that the energy efficiency of the battery cluster remains stable.

6. A battery cluster health online monitoring device, characterized in that: include: Data acquisition unit, battery cluster calculation unit, single cell calculation unit and inconsistency determination unit; The data acquisition unit is configured to obtain, from a battery management system, an operating voltage of a battery cluster, an operating current of the battery cluster, an operating voltage of a first battery cell, and an operating current of the first battery cell, wherein the operating voltage is a voltage during a charging process or a discharging process, the operating current is a current during a charging process or a discharging process, and the first battery cell is one of the battery cells included in the battery cluster; The battery cluster calculation unit is configured to calculate the conversion energy of the battery cluster based on the operating voltage and the operating current of the battery cluster, wherein the conversion energy of the battery cluster is the charging energy of the battery cluster during the charging process or the discharging energy of the battery cluster during the discharging process; The single cell calculation unit is configured to calculate the conversion energy of the first single cell according to the operating voltage and the operating current of the first single cell, wherein the conversion energy of the first single cell is the charging energy of the first single cell during the charging process or the discharging energy of the first single cell during the discharging process; The inconsistency determining unit is configured to determine the inconsistency of the single cells of the battery cluster according to the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells, wherein the cell inconsistency represents the degree of inconsistency of the performance of each single cell of the battery cluster; The determining of the inconsistency of the single cells of the battery cluster according to the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single cells includes: Performing linear fitting on the multiple conversion energies of the battery cluster and the multiple conversion energies of the first single battery cell and performing derivative thereof to obtain a first slope; If the first slope increases, it is determined that the inconsistency of the single cells of the battery cluster is aggravated; If the first slope remains stable, it is determined that the inconsistency of the single cells of the battery cluster is stable.

7. The device according to claim 6, characterized in that The device further comprises: a first selection unit and a second selection unit; The first selection unit is configured to, before obtaining the operating voltage of the battery cluster, the operating current of the battery cluster, the operating voltage of the first single cell, and the operating current of the first single cell from the battery management system, if the battery cluster is a battery cluster whose operating time is less than a preset operating threshold, select a single cell that meets a first condition from each single cell included in the battery cluster as the first single cell, wherein the first condition is: the voltage of the single cell is closest to the average voltage of all the single cells of the battery cluster and the capacity of the single cell is closest to the average capacity of all the single cells of the battery cluster; The second selection unit is configured to select, if the battery cluster has an operating time greater than the preset operating threshold, a single cell that satisfies a second condition from the single cells included in the battery cluster as the first single cell, wherein the second condition is that the temperature of the single cell is closest to the average temperature of all the single cells in the battery cluster.

8. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the method for online monitoring of battery cluster health according to any one of claims 1 to 5 is implemented.

9. An electronic device, characterized in that: The electronic device includes at least one processor, and at least one memory and a bus connected to the processor; wherein the processor and the memory communicate with each other via the bus; the processor is configured to call program instructions in the memory to execute the method for online monitoring of battery cluster health according to any one of claims 1 to 5.

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