Battery cell consistency management method and system for energy storage module

Abstract

The present invention relates to the field of battery management, and discloses a battery cell consistency management method and system for an energy storage module, comprising the following steps: performing multiple charge and discharge tests on a battery cluster in the energy storage module to obtain multiple voltage data sequences of the corresponding battery cluster, obtaining a voltage data sequence of each battery module of the battery cluster based on multiple sets of voltage data sequences, obtaining a voltage change value of the battery module according to the voltage data sequence of the battery module, obtaining the charge and discharge consistency of the battery module according to the voltage change value of the battery module, arranging the voltage data sequence of each battery module with consistent charge and discharge consistency according to the battery module sequence number, and if the voltage consistency of the battery cluster is consistent, obtaining the battery capacity of the energy storage module after consistency management according to the capacity of all battery clusters after consistency management, and completing battery management. The present invention reduces the non-balanced aging phenomenon of the battery module and prolongs the service life.

Description

Technical Field

[0001] The present invention relates to the field of battery management, and in particular to a battery cell consistency management method and system for an energy storage module. Background Art

[0002] With the rapid development of renewable energy and the growing demand for energy storage in power systems, energy storage systems, as a bridge connecting energy production and consumption, are becoming increasingly important. As a core component of energy storage systems, the performance of energy storage modules is directly related to the efficiency, safety and reliability of the entire system. In particular, in large-scale energy storage systems, the consistency of battery modules has become one of the key factors affecting system performance.

[0003] A battery module is composed of multiple battery cells connected in series or in parallel, and an energy storage module may contain multiple such battery clusters. In actual applications, due to differences in manufacturing processes, use environments, aging levels and other factors, the performance of each battery cell and even each battery module will be different, which leads to inconsistencies in parameters such as voltage, current, and temperature during the charging and discharging process of the battery module. This inconsistency will not only reduce the overall capacity utilization of the energy storage system, but may also cause overcharging and over-discharging of individual battery cells, thereby causing safety hazards and shortening the service life of the entire energy storage system.

[0004] Traditional battery management strategies often focus on the monitoring and management of individual battery cells or simple battery packs, and it is difficult to effectively address the consistency management issues of complex battery modules in large-scale energy storage systems. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a battery cell consistency management method for an energy storage module, comprising the following steps:

[0006] Step 1: Perform multiple charge and discharge tests on the battery cluster in the energy storage module to obtain multiple voltage data sequences of the corresponding battery cluster, wherein the battery cluster includes M battery modules and battery module serial numbers, and the voltage data sequence includes voltage data of the M battery modules;

[0007] Step 2: based on multiple groups of voltage data sequences, obtain a voltage data sequence of each battery module of the battery cluster, obtain a voltage change value of the battery module according to the voltage data sequence of the battery module, and obtain the charge and discharge consistency of the battery module according to the voltage change value of the battery module. If there is no inconsistent charge and discharge consistency of the battery module, proceed to step 3; otherwise, shield the battery module with inconsistent charge and discharge consistency and proceed to step 3;

[0008] Step 3, arranging the voltage data sequence of each battery module with consistent charge and discharge consistency according to the battery module serial number to obtain the arranged voltage data sequence of the battery module, and obtaining the voltage consistency of the battery cluster based on the arranged voltage data sequence of the battery module. If the voltage consistency of the battery cluster is consistent, proceed to step 6, otherwise, proceed to step 4;

[0009] Step 4: locate and shield the battery modules with inconsistent voltages according to the difference between the voltage data sequences of the arranged battery modules. If the energy storage module is a single battery cluster, proceed to step 6; if the energy storage module is a multi-battery cluster, proceed to step 5.

[0010] Step 5: According to the battery modules shielded by each battery cluster, the capacity loss of the corresponding battery cluster is obtained respectively. If there is no battery cluster whose capacity loss is greater than the set loss threshold, consistency correction is performed on each battery cluster, and step 6 is entered; otherwise, the early warning module issues a battery failure early warning;

[0011] Step 6: According to the capacity of all battery clusters after consistency management, the battery capacity of the energy storage module after consistency management is obtained to complete the battery management.

[0012] Furthermore, the battery cluster includes a plurality of battery modules connected in parallel, and the battery module includes a plurality of battery units connected in series.

[0013] Further, the voltage change value of the battery module is obtained according to the voltage data sequence of the battery module, and the charge and discharge consistency of the battery module is obtained according to the charge and discharge voltage change value of the battery module, including:

[0014] The voltage change value of the battery module is obtained according to the minimum voltage value and the maximum voltage value in the voltage data sequence of the battery module. If the voltage change value of the battery module is less than the set voltage change value, the charging and discharging of each battery unit connected in series in the battery module are consistent, otherwise the charging and discharging of the battery module are inconsistent.

[0015] Furthermore, the voltage consistency of the battery cluster is obtained based on the voltage data sequence of the arranged battery modules, including:

[0016] If the difference between the maximum voltage change value and the minimum voltage change value in the battery module is less than the set battery module differential pressure threshold, the battery cluster voltages are consistent; otherwise, the voltages are inconsistent.

[0017] Furthermore, the method of locating and shielding battery modules with inconsistent voltages according to the difference in voltage data between the arranged voltage data sequences of the battery modules includes:

[0018] According to the average value of the difference in voltage change values ​​between the battery modules, if the difference between the voltage change value of the battery module and the average value is not less than the average value, it is a battery module with inconsistent voltage.

[0019] Furthermore, the battery modules shielded by each battery cluster are used to obtain the capacity loss of the corresponding battery cluster, including:

[0020] According to the ratio of the battery module shielded by the battery cluster to the initial battery capacity of the battery cluster, the capacity loss of the corresponding battery cluster is obtained.

[0021] Furthermore, the consistency calibration of each battery cluster includes:

[0022] The capacity loss of each battery cluster is obtained respectively, and the capacity of the battery cluster with the largest capacity loss is taken as the standard capacity. The capacities of the remaining battery clusters are adjusted to be consistent, thus completing the consistency correction.

[0023] A battery cell consistency management system for an energy storage module, applying the battery cell consistency management method for an energy storage module, comprising: a charge and discharge management module, a data acquisition module, an early warning module, a data processing module and a data storage module;

[0024] The charge and discharge management module, data acquisition module, early warning module and data storage module are respectively connected to the data processing module.

[0025] The beneficial effects of the present invention are as follows: by accurately identifying and processing the inconsistency problem of battery modules, the capacity utilization rate and energy conversion efficiency of the energy storage system are effectively improved. The potential safety hazards caused by overcharging and over-discharging of battery cells are avoided, and the system failure rate and maintenance costs are reduced. Through consistency management and capacity correction, the unbalanced aging phenomenon of battery modules is reduced, and the service life of the entire energy storage system is extended. The automated management system and early warning mechanism enable operation and maintenance personnel to detect and deal with potential problems in a timely manner, reducing the frequency and difficulty of manual intervention. It is not only suitable for energy storage modules of a single battery cluster, but also for complex energy storage systems containing multiple battery clusters, and has wide applicability and scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a flow chart of a battery cell consistency management method for an energy storage module;

[0027] Figure 2 A schematic diagram of a battery cell consistency management system for an energy storage module;

[0028] Figure 3 Schematic diagram of the data acquisition device. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0030] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0031] like Figure 1 As shown, a battery cell consistency management method for an energy storage module includes the following steps:

[0032] Step 1: Perform multiple charge and discharge tests on the battery cluster in the energy storage module to obtain multiple voltage data sequences of the corresponding battery cluster, wherein the battery cluster includes M battery modules and battery module serial numbers, and the voltage data sequence includes voltage data of the M battery modules;

[0033] Step 2: based on multiple groups of voltage data sequences, obtain a voltage data sequence of each battery module of the battery cluster, obtain a voltage change value of the battery module according to the voltage data sequence of the battery module, and obtain the charge and discharge consistency of the battery module according to the voltage change value of the battery module. If there is no inconsistent charge and discharge consistency of the battery module, proceed to step 3; otherwise, shield the battery module with inconsistent charge and discharge consistency and proceed to step 3;

[0034] Step 3, arranging the voltage data sequence of each battery module with consistent charge and discharge consistency according to the battery module serial number to obtain the arranged voltage data sequence of the battery module, and obtaining the voltage consistency of the battery cluster based on the arranged voltage data sequence of the battery module. If the voltage consistency of the battery cluster is consistent, proceed to step 6, otherwise, proceed to step 4;

[0035] Step 4: locate and shield the battery modules with inconsistent voltages according to the difference between the voltage data sequences of the arranged battery modules. If the energy storage module is a single battery cluster, proceed to step 6; if the energy storage module is a multi-battery cluster, proceed to step 5.

[0036] Step 5: According to the battery modules shielded by each battery cluster, the capacity loss of the corresponding battery cluster is obtained respectively. If there is no battery cluster whose capacity loss is greater than the set loss threshold, consistency correction is performed on each battery cluster, and step 6 is entered; otherwise, the early warning module issues a battery failure early warning;

[0037] Step 6: According to the capacity of all battery clusters after consistency management, the battery capacity of the energy storage module after consistency management is obtained to complete the battery management.

[0038] The battery cluster includes a plurality of battery modules connected in parallel, and the battery module includes a plurality of battery units connected in series.

[0039] The method of obtaining the voltage change value of the battery module according to the voltage data sequence of the battery module, and obtaining the charge and discharge consistency of the battery module according to the charge and discharge voltage change value of the battery module, includes:

[0040] The voltage change value of the battery module is obtained according to the minimum voltage value and the maximum voltage value in the voltage data sequence of the battery module. If the voltage change value of the battery module is less than the set voltage change value, the charging and discharging of each battery unit connected in series in the battery module are consistent, otherwise the charging and discharging of the battery module are inconsistent.

[0041] The method of obtaining the voltage consistency of the battery cluster based on the arranged voltage data sequence of the battery modules includes:

[0042] If the difference between the maximum voltage change value and the minimum voltage change value in the battery module is less than the set battery module differential pressure threshold, the battery cluster voltages are consistent; otherwise, the voltages are inconsistent.

[0043] The method of locating and shielding battery modules with inconsistent voltages according to the difference in voltage data between the arranged voltage data sequences of the battery modules comprises:

[0044] According to the average value of the difference in voltage change values ​​between the battery modules, if the difference between the voltage change value of the battery module and the average value is not less than the average value, it is a battery module with inconsistent voltage.

[0045] The battery modules shielded by each battery cluster are used to obtain the capacity loss of the corresponding battery cluster, including:

[0046] According to the ratio of the battery module shielded by the battery cluster to the initial battery capacity of the battery cluster, the capacity loss of the corresponding battery cluster is obtained.

[0047] The consistency calibration of each battery cluster includes:

[0048] The capacity loss of each battery cluster is obtained respectively, and the capacity of the battery cluster with the largest capacity loss is taken as the standard capacity. The capacities of the remaining battery clusters are adjusted to be consistent, thus completing the consistency correction.

[0049] like Figure 2 As shown, a battery cell consistency management system for an energy storage module, applying the battery cell consistency management method for an energy storage module, comprises: a charge and discharge management module, a data acquisition module, an early warning module, a data processing module and a data storage module;

[0050] The charge and discharge management module, data acquisition module, early warning module and data storage module are respectively connected to the data processing module.

[0051] like Figure 3As shown, the data acquisition module includes multiple data collectors, and the multiple data collectors are respectively connected to the data processing modules.

[0052] Specifically, the battery cell consistency management method for an energy storage module provided by the present invention comprises the following steps:

[0053] Step 1: Data Collection

[0054] By performing multiple charge and discharge tests on the battery cluster in the energy storage module, multiple voltage data sequences of the corresponding battery cluster are obtained. The battery cluster here consists of M battery modules, each battery module contains multiple battery cells connected in series, and each battery cluster and battery module has a unique serial number.

[0055] The voltage data sequence records the voltage changes of each battery module during each charge and discharge process, and is the basis for subsequent analysis.

[0056] Step 2: Determine the charge and discharge consistency of the battery module

[0057] Based on the multiple groups of voltage data sequences collected in step 1, the voltage data sequence of each battery module is extracted.

[0058] The voltage change value of each battery module is calculated, which is usually achieved by comparing the maximum and minimum values ​​in the voltage data series.

[0059] The charge and discharge consistency of the battery module is determined based on the voltage change value. If the voltage change value is less than the set threshold, it is considered that the battery cells in the battery module are charged and discharged consistently; otherwise, it is considered inconsistent and the battery module is marked as to be shielded.

[0060] Step 3: Determine the voltage consistency of the battery cluster

[0061] For battery modules with consistent charge and discharge consistency, the voltage data sequence is arranged according to its serial number.

[0062] Based on the arranged voltage data sequence, the voltage consistency of the battery cluster is evaluated. This is usually achieved by comparing the difference between the maximum and minimum voltage change values ​​of each battery module. If the difference is less than the set differential voltage threshold, the battery cluster voltage is considered consistent; otherwise, it proceeds to the next step for further processing.

[0063] Step 4: Locate and shield battery modules with inconsistent voltages

[0064] In the case of inconsistent voltages in the battery cluster, the battery modules with inconsistent voltages can be located by comparing the differences in voltage changes between the battery modules. Specifically, the average value of the differences in voltage changes between the battery modules can be calculated, and the battery modules with a large difference from the average value can be considered inconsistent.

[0065] The inconsistent battery modules that are located are shielded to avoid their impact on the performance of the entire energy storage module.

[0066] Step 5: Multi-battery cluster capacity loss assessment and consistency correction

[0067] In the case where the energy storage module includes multiple battery clusters, the capacity loss of each battery cluster is evaluated based on the battery modules shielded by each battery cluster. The capacity loss can be calculated by comparing the battery capacity before and after shielding.

[0068] If the capacity loss of all battery clusters does not exceed the set loss threshold, consistency correction is performed on each battery cluster. The correction method may be to adjust the charging or discharging strategy of the battery cluster so that the capacity of each battery cluster tends to be consistent.

[0069] If the capacity loss of the battery cluster exceeds the loss threshold, the warning module will be triggered to issue a battery failure warning, prompting the operation and maintenance personnel to conduct further inspection and processing.

[0070] Step 6: Determine the battery capacity of the energy storage module

[0071] After completing the consistency management of all battery clusters, the overall battery capacity of the energy storage module is calculated based on the capacity of each battery cluster.

[0072] Complete the battery management process to ensure that the energy storage module can operate efficiently and safely.

[0073] In order to implement the above method, the present invention also provides a battery cell consistency management system method for an energy storage module, the system comprising:

[0074] Charge and discharge management module: responsible for controlling the charge and discharge process of the energy storage module to ensure the accuracy and reliability of the test data.

[0075] Data acquisition module: contains multiple data collectors, which are connected to each battery module and are responsible for real-time collection of key data such as voltage and current.

[0076] Data processing module: processes and analyzes the collected data and executes each step in the above method, including consistency judgment, capacity loss assessment, etc.

[0077] Early warning module: issues an early warning signal when an abnormal situation (such as excessive capacity loss) is detected.

[0078] Data storage module: used to store test data, analysis results, system configuration information, etc.

[0079] The modules are interconnected through an efficient data communication mechanism, together forming a complete and efficient battery module consistency management system.

[0080] Embodiment 1

[0081] Assume an energy storage module, which includes a battery cluster consisting of 10 battery modules (M=10), each of which consists of 20 battery cells connected in series. In order to implement the battery module consistency management method provided by the present invention, we follow the following steps:

[0082] Step 1: Data Collection

[0083] The charge and discharge management module is used to perform multiple (e.g., 5) charge and discharge tests on the battery cluster. The 10 data collectors of the data acquisition module are connected to the 10 battery modules respectively to collect voltage data in real time during each charge and discharge process. Each data collector sends the collected voltage data sequence to the data processing module for storage and processing.

[0084] Step 2: Determine the charge and discharge consistency of the battery module

[0085] The data processing module extracts the voltage data sequence of each battery module from the data storage module. The voltage data sequence of each battery module is analyzed to calculate the voltage change value (i.e., the difference between the maximum value and the minimum value). The voltage change value threshold is set to 0.1V. If the voltage change value of a battery module is less than 0.1V, it is considered that the battery module is charged and discharged consistently; otherwise, it is marked as to be shielded. Assume that after judgment, battery modules No. 3 and No. 7 are marked as to be shielded.

[0086] Step 3: Determine the voltage consistency of the battery cluster

[0087] For the remaining 8 battery modules with consistent charge and discharge consistency, arrange the voltage data sequence according to the sequence number. Calculate the difference between the maximum and minimum voltage change values ​​of these 8 battery modules. Set the differential voltage threshold to 0.05V. If the difference is less than 0.05V, it is considered that the battery cluster voltage is consistent; otherwise, proceed to the next step. Assume that the judgment result shows that the battery cluster voltage is inconsistent.

[0088] Step 4: Locate and shield battery modules with inconsistent voltages

[0089] Calculate the average of the voltage change differences between the remaining 8 battery modules. Compare the voltage change value of each battery module with the average value. If the difference is greater than the average value, it is considered inconsistent. Assume that after positioning, it is found that the voltages of battery modules No. 2 and No. 5 are inconsistent, and they are shielded.

[0090] Step 5: Multi-battery cluster capacity loss assessment and consistency correction

[0091] Evaluate the battery cluster capacity loss after shielding battery modules No. 3, No. 7, No. 2, and No. 5. Assuming that the capacity loss does not exceed the set loss threshold (such as 5%), make consistency corrections to the remaining battery modules, such as adjusting the charging current or discharge depth, so that the performance of each battery module tends to be consistent.

[0092] Step 6: Determine the battery capacity of the energy storage module

[0093] After completing the consistency calibration, re-evaluate the capacity of the battery cluster. Determine the overall battery capacity of the energy storage module based on the calibrated battery cluster capacity. Complete the battery management process to ensure that the energy storage module can operate efficiently and safely.

[0094] Embodiment 2

[0095] Assume a more complex energy storage module, which includes two battery clusters (Cluster A and Cluster B), each battery cluster consists of 12 battery modules (M=12), and each battery module consists of 30 battery cells connected in series. In order to implement the battery module consistency management method provided by the present invention, we follow the following steps:

[0096] Step 1 to Step 4: Similar to Example 1, data collection, battery module charge and discharge consistency judgment, battery cluster voltage consistency judgment, and voltage inconsistent battery module positioning and shielding are performed on cluster A and cluster B respectively. Assume that after judgment and processing, 2 battery modules in cluster A are shielded and 3 battery modules in cluster B are shielded.

[0097] Step 5: Multi-battery cluster capacity loss assessment and consistency correction

[0098] Evaluate the capacity loss of cluster A and cluster B after shielding the battery module. Assume that the capacity loss of cluster A is 3% and the capacity loss of cluster B is 4%, both of which do not exceed the set loss threshold (such as 5%). Perform consistency correction on cluster A and cluster B.

[0099] Since the capacity loss of cluster A and cluster B is small, the capacity of the two clusters can be made consistent by adjusting the charging strategy (such as extending the charging time, reducing the charging current, etc.) or the discharging strategy (such as adjusting the discharge depth, increasing the discharge interval, etc.). Assume that after correction, the capacity difference between cluster A and cluster B is reduced to less than 1%.

[0100] Step 6: Determine the battery capacity of the energy storage module

[0101] After completing the consistency correction of cluster A and cluster B, re-evaluate the capacities of the two clusters respectively. According to the corrected capacities of cluster A and cluster B, calculate the overall battery capacity of the energy storage module (considering the parallel relationship of the two clusters).

[0102] Complete the battery management process to ensure that the energy storage module can operate efficiently and safely with high capacity utilization and stability.

[0103] Through these two examples, we can see the specific operation process and effect of the battery module consistency management method provided by the present invention in practical applications. The method can effectively identify and handle the inconsistency problem of the battery module and improve the overall performance and safety of the energy storage module.

Claims

1. A battery cell consistency management method for an energy storage module, characterized in that: The steps include: Step 1: Perform multiple charge and discharge tests on the battery cluster in the energy storage module to obtain multiple voltage data sequences of the corresponding battery cluster, wherein the battery cluster includes M battery modules and battery module serial numbers, and the voltage data sequence includes voltage data of the M battery modules; Step 2: based on multiple groups of voltage data sequences, obtain a voltage data sequence of each battery module of the battery cluster, obtain a voltage change value of the battery module according to the voltage data sequence of the battery module, and obtain the charge and discharge consistency of the battery module according to the voltage change value of the battery module. If there is no inconsistent charge and discharge consistency of the battery module, proceed to step 3; otherwise, shield the battery module with inconsistent charge and discharge consistency and proceed to step 3; Step 3, arranging the voltage data sequence of each battery module with consistent charge and discharge consistency according to the battery module serial number to obtain the arranged voltage data sequence of the battery module, and obtaining the voltage consistency of the battery cluster based on the arranged voltage data sequence of the battery module. If the voltage consistency of the battery cluster is consistent, proceed to step 6, otherwise, proceed to step 4; Step 4: locate and shield the battery modules with inconsistent voltages according to the difference between the voltage data sequences of the arranged battery modules. If the energy storage module is a single battery cluster, proceed to step 6; if the energy storage module is a multi-battery cluster, proceed to step 5. Step 5: According to the battery modules shielded by each battery cluster, the capacity loss of the corresponding battery cluster is obtained respectively. If there is no battery cluster whose capacity loss is greater than the set loss threshold, consistency correction is performed on each battery cluster, and step 6 is entered; otherwise, the early warning module issues a battery failure early warning; Step 6: According to the capacity of all battery clusters after consistency management, the battery capacity of the energy storage module after consistency management is obtained to complete the battery management.

2. The battery cell consistency management method for an energy storage module according to claim 1, characterized in that: The battery cluster includes a plurality of battery modules connected in parallel, and the battery module includes a plurality of battery units connected in series.

3. The battery cell consistency management method for an energy storage module according to claim 2, characterized in that: The method of obtaining the voltage change value of the battery module according to the voltage data sequence of the battery module, and obtaining the charge and discharge consistency of the battery module according to the voltage change value of the battery module, includes: The voltage change value of the battery module is obtained according to the minimum voltage value and the maximum voltage value in the voltage data sequence of the battery module. If the voltage change value of the battery module is less than the set voltage change value, the charging and discharging of each battery unit connected in series in the battery module are consistent, otherwise the charging and discharging of the battery module are inconsistent.

4. The battery cell consistency management method for an energy storage module according to claim 3, characterized in that: The voltage consistency of the battery cluster is obtained based on the voltage data sequence of the arranged battery modules, including: If the difference between the maximum voltage change value and the minimum voltage change value in the battery module is less than the set battery module differential pressure threshold, the battery cluster voltages are consistent; otherwise, the voltages are inconsistent.

5. The battery cell consistency management method for an energy storage module according to claim 4, characterized in that: The method of locating and shielding battery modules with inconsistent voltages according to the difference in voltage data between the arranged voltage data sequences of the battery modules comprises: According to the average value of the difference in voltage change values ​​between the battery modules, if the difference between the voltage change value of the battery module and the average value is not less than the average value, it is a battery module with inconsistent voltage.

6. The battery cell consistency management method for an energy storage module according to claim 5, characterized in that: The battery modules shielded by each battery cluster are used to obtain the capacity loss of the corresponding battery cluster, including: According to the ratio of the battery module shielded by the battery cluster to the initial battery capacity of the battery cluster, the capacity loss of the corresponding battery cluster is obtained.

7. The battery cell consistency management method for an energy storage module according to claim 6, characterized in that: The consistency calibration of each battery cluster includes: The capacity loss of each battery cluster is obtained respectively, and the capacity of the battery cluster with the largest capacity loss is taken as the standard capacity. The capacities of the remaining battery clusters are adjusted to be consistent, thus completing the consistency correction.

8. A battery cell consistency management system for an energy storage module, characterized in that: The battery cell consistency management method for an energy storage module according to any one of claims 1 to 7 comprises: a charge and discharge management module, a data acquisition module, an early warning module, a data processing module and a data storage module; The charge and discharge management module, data acquisition module, early warning module and data storage module are respectively connected to the data processing module.

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