Battery active equalization control method and system and storage medium

Abstract

The invention relates to a battery active equalization control method and system and a storage medium. The method comprises the following steps: acquiring terminal voltage data and static voltage data of each single battery in a battery system; obtaining target terminal voltage difference data corresponding to each single battery according to each terminal voltage data, and obtaining target capacity deviation data corresponding to each single battery according to each static voltage data; and when the target tail end voltage difference data of any single battery meets a preset equalization condition, determining the corresponding single battery as a to-be-equalized battery, and performing an equalization action corresponding to the preset equalization condition on the to-be-equalized battery based on the target capacity deviation data, thereby realizing active equalization of each single battery in the battery system. The balance of voltage difference distribution of the battery system at the charging and discharging tail ends is ensured, and the charging and discharging quantity of the battery system is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery active balancing control method, system, and storage medium. Background Art

[0002] BMS (Battery Management System) active balancing adjusts the voltage differences between individual cells to bring the voltage of each cell in the battery pack closer to a consistent level. Active balancing of individual cells not only prevents accelerated aging of some cells due to overcharging or over-discharging, but also maximizes the overall capacity of the battery pack, extending its lifespan. BMS active balancing is a key technology for ensuring battery pack performance, lifespan, and safety, and is of great practical significance, particularly in applications such as electric vehicles and energy storage systems.

[0003] Currently, in the existing active battery balancing control method, the balancing effect of the battery system at the end of charging and discharging is poor, which limits the charging and discharging capacity of the battery system. Summary of the Invention

[0004] Based on this, a battery active balancing control method, system and storage medium are provided.

[0005] In a first aspect, the present application provides a battery active balancing control method, comprising the following steps:

[0006] Obtain terminal voltage data and static voltage data of each single cell in the battery system;

[0007] Obtaining target terminal voltage difference data corresponding to each single cell based on each terminal voltage data, and obtaining target capacity deviation data corresponding to each single cell based on each static voltage data;

[0008] When the target terminal voltage difference data of any single cell meets the preset balancing condition, the corresponding single cell is determined as a cell to be balanced, and a balancing action corresponding to the preset balancing condition is performed on the cell to be balanced based on the target capacity deviation data.

[0009] In one embodiment, the step of obtaining target terminal voltage difference data corresponding to each single battery cell according to each terminal voltage data includes:

[0010] The terminal voltage data are normalized based on a preset normalization model to obtain the target terminal voltage difference data.

[0011] In one embodiment, the step of normalizing each terminal voltage data based on a preset normalization model to obtain each target terminal voltage difference data includes:

[0012] According to each terminal voltage data, the terminal voltage average value is obtained;

[0013] Performing difference processing on each terminal voltage data and the terminal voltage average value to obtain the initial terminal voltage difference data of each single battery;

[0014] Each initial terminal voltage difference data is amplified and converted to obtain target terminal voltage data.

[0015] In one embodiment, the step of obtaining target capacity deviation data corresponding to each single cell according to each static voltage data includes:

[0016] According to each static voltage data, query the preset voltage-capacity matching table to obtain the remaining capacity data of each corresponding static voltage data;

[0017] According to each remaining capacity data, average capacity data is obtained;

[0018] The remaining capacity data and the average capacity data are subjected to difference processing to obtain the target capacity deviation data.

[0019] In one embodiment, the target terminal voltage difference data includes terminal charging voltage difference data and terminal discharging voltage difference data; the preset balancing condition includes the terminal charging voltage difference data being higher than a first charging threshold and the terminal discharging voltage difference data being higher than a first discharging threshold, the terminal charging voltage difference data being lower than a second charging threshold and the terminal discharging voltage difference data being lower than a second discharging threshold;

[0020] The steps of performing a balancing action corresponding to a preset balancing condition on the battery to be balanced based on the target capacity deviation data include:

[0021] When the terminal charging voltage difference data is higher than a first charging threshold and the terminal discharging voltage difference data is higher than a first discharging threshold, a discharge balancing action is performed on the battery to be balanced based on the corresponding target capacity deviation data;

[0022] When the terminal charging voltage difference data is lower than a second charging threshold and the terminal discharging voltage difference data is lower than a second discharging threshold, a charging balancing action is performed on the battery to be balanced based on the corresponding target capacity deviation data.

[0023] In one embodiment, the preset balancing condition further includes: the terminal charging voltage difference data is higher than the first charging threshold and the terminal discharging voltage difference data is lower than the second discharging threshold; the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold;

[0024] The steps of performing a balancing action corresponding to a preset balancing condition on the battery to be balanced based on the target capacity deviation data include:

[0025] When the terminal charge voltage difference data is higher than the first charge threshold and the terminal discharge voltage difference data is lower than the second discharge threshold, a discharge balancing action is performed on the battery to be balanced based on the preset discharge balancing capacity until the difference between the next terminal charge voltage difference data and the next terminal discharge voltage difference data falls within the preset voltage difference threshold range;

[0026] When the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold, a charge balancing action is performed on the battery to be balanced based on the preset charge balancing capacity until the difference between the next terminal charging voltage difference data and the next terminal discharging voltage difference data falls within the preset voltage difference threshold range.

[0027] In one embodiment, the terminal voltage data includes terminal charging voltage data and terminal discharging voltage data;

[0028] The steps of obtaining the terminal voltage data of each single battery in the battery system include:

[0029] When the charging terminal current of the battery system reaches a first current threshold, the full charge terminal voltage reaches a first voltage threshold, and the single charge SOC reaches a first SOC threshold, acquiring terminal charging voltage data of each single battery;

[0030] When the discharge terminal current of the battery system reaches a second current threshold, the full discharge terminal voltage reaches a second voltage threshold, and the single discharge SOC reaches a second SOC threshold, terminal discharge voltage data of each single battery is obtained.

[0031] In one embodiment, the step of obtaining static voltage data of each single battery in the battery system includes:

[0032] When the discharge end current of the battery system reaches the third current threshold, the full discharge end voltage reaches the third voltage threshold, the single discharge SOC reaches the second SOC threshold, and the discharge end standby time reaches the preset time threshold, the static voltage data of each single battery is obtained.

[0033] In a second aspect, the present application further provides a battery active balancing control system, comprising a processing device and a battery system, wherein the battery system comprises a plurality of single cells, and the processing device is connected to each single cell;

[0034] The processing device is used to execute the steps of any one of the above-mentioned battery active balancing control methods.

[0035] In a third aspect, the present application further provides a computer storage medium having a computer program stored thereon, which implements the steps of any of the above-mentioned battery active balancing control methods when the computer program is executed by a processor.

[0036] One of the above technical solutions has the following advantages and beneficial effects:

[0037] In the above-mentioned active battery balancing control method, the terminal voltage data and static voltage data of each single cell in the battery system are obtained; based on each terminal voltage data, the target terminal voltage difference data corresponding to each single cell is obtained, and based on each static voltage data, the target capacity deviation data corresponding to each single cell is obtained; when the target terminal voltage difference data of any single cell meets the preset balancing condition, the corresponding single cell is determined to be a cell to be balanced, and based on the target capacity deviation data, the balancing action corresponding to the preset balancing condition is performed on the cell to be balanced, thereby achieving active balancing of each single cell in the battery system. This application extracts the terminal voltage and static voltage of each single cell in the battery system, calculates the terminal voltage difference corresponding to the terminal voltage, and calculates the capacity deviation corresponding to the static voltage, determines whether the single cell meets the preset balancing condition, and adopts the corresponding charge and discharge balancing action to ensure the balance of the voltage difference distribution of the battery system during charge and discharge, thereby improving the charge and discharge capacity of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the application environment of the active battery balancing control method in an embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of a first flow chart of a method for active battery balancing control in an embodiment of the present application;

[0040] Figure 3 This is a flow chart of the target terminal pressure difference data acquisition step in an embodiment of the present application;

[0041] Figure 4 Schematic diagram of the process of obtaining target capacity deviation data in an embodiment of the present application;

[0042] Figure 5 This is a first flow chart of the equalization processing step in the embodiment of the present application;

[0043] Figure 6 This is a second flow chart of the equalization processing step in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0045] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] Additionally, the term "plurality" shall mean two or more.

[0047] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0048] The battery active balancing control method provided in this application can be applied to Figure 1 In the application environment shown, a battery system 200 includes multiple battery cells 202, and a processing device 100 is connected to each battery cell 202. The processing device 100 may include a processor and a memory. The processor is connected to the memory, and the memory may be used to store data such as terminal voltage data, static voltage data, target terminal voltage differential data, and target capacity deviation data. The processor may be used to obtain terminal voltage data and static voltage data for each battery cell 202 in the battery system 200; based on each terminal voltage data, the target terminal voltage differential data corresponding to each battery cell 202 is obtained; and based on each static voltage data, the target capacity deviation data corresponding to each battery cell 202 is obtained; when the target terminal voltage differential data of any battery cell 202 meets a preset balancing condition, the corresponding battery cell 202 is determined to be a battery to be balanced, and balancing actions corresponding to the preset balancing condition are performed on the battery to be balanced based on the target capacity deviation data. The processing device 100 also includes a display connected to the processor, and the display is used to graphically display data such as terminal voltage data, static voltage data, target terminal voltage differential data, and target capacity deviation data. For example, the processing device 100 may be a battery management system (BMS).

[0049] In one embodiment, Figure 2 As shown, a battery active balancing control method is also provided, comprising the following steps:

[0050] Step S210: Acquire terminal voltage data and static voltage data of each single cell in the battery system.

[0051] The battery system may be a lithium battery system, which may include multiple single cells, each of which may be connected in series and / or in parallel. The single cells may be lithium-ion batteries, and may be square or cylindrical in shape. Terminal voltage data refers to the voltage data of the corresponding single cell at the end of charge or discharge; static voltage data refers to the voltage data of the corresponding single cell at rest after discharge. For example, multiple voltage acquisition modules may be provided, each connected to a single cell, and used to collect the terminal voltage and static voltage of the corresponding single cell.

[0052] For example, the most recent charge and discharge terminal voltage of each single cell in the battery system is collected to obtain the terminal voltage data of each single cell; the most recent discharge static voltage of each single cell in the battery system is collected to obtain the static voltage data of each single cell.

[0053] Step S220 : Obtain target terminal voltage difference data corresponding to each single cell according to each terminal voltage data, and obtain target capacity deviation data corresponding to each single cell according to each static voltage data.

[0054] The target terminal voltage difference data refers to the voltage difference between the terminal voltage of the corresponding single cell and a preset voltage. For example, the preset voltage may be the average voltage or median voltage of each single cell. The target capacity deviation data refers to the capacity difference between the current capacity of the single cell and a preset capacity. For example, the preset capacity may be the average capacity or median capacity of each single cell.

[0055] For example, the terminal voltage data of each cell is processed to obtain the target terminal voltage differential data for each cell. Based on the static voltage data of each cell, the current capacity data of each corresponding static voltage data is obtained. The current capacity data of each cell is then processed to obtain the target capacity deviation data for each cell.

[0056] Step S230 : When the target terminal voltage difference data of any single cell meets the preset balancing condition, the corresponding single cell is determined as a cell to be balanced, and a balancing action corresponding to the preset balancing condition is performed on the cell to be balanced based on the target capacity deviation data.

[0057] The preset balancing conditions are preset by the system. Balancing actions refer to balancing methods tailored to the charging and discharging requirements. The preset balancing conditions match the charging requirements. That is, when the target terminal differential pressure data for a cell meets the preset balancing conditions, the corresponding balancing action is performed on the cell. Cells to be balanced are cells whose target terminal differential pressure data meets the preset balancing conditions.

[0058] For example, by comparing the target terminal differential pressure data of each single cell with the preset balancing condition, and based on the comparison result, when the target terminal differential pressure data of any single cell meets the preset balancing condition, the corresponding single cell is determined to be a cell to be balanced, and the balancing method of the cell to be balanced is determined to be the balancing method corresponding to the preset balancing condition. Then, based on the target capacity deviation data, the corresponding balancing action is performed on the cell to be balanced, thereby achieving efficient and reliable balancing control of each single cell in the battery system.

[0059] In the above-mentioned embodiment, the terminal voltage data and static voltage data of each single cell in the battery system are obtained; based on each terminal voltage data, the target terminal voltage difference data corresponding to each single cell is obtained; and based on each static voltage data, the target capacity deviation data corresponding to each single cell is obtained; when the target terminal voltage difference data of any single cell meets the preset balancing condition, the corresponding single cell is determined to be a cell to be balanced, and based on the target capacity deviation data, a balancing action corresponding to the preset balancing condition is performed on the cell to be balanced, thereby achieving active balancing of each single cell in the battery system. The present application extracts the terminal voltage and static voltage of each single cell in the battery system, calculates the terminal voltage difference corresponding to the terminal voltage, and calculates the capacity deviation corresponding to the static voltage, to determine whether the single cell meets the preset balancing condition, and adopts the corresponding charge and discharge balancing action to ensure the balance of the voltage difference distribution of the battery system during charge and discharge, thereby improving the charge and discharge capacity of the battery system.

[0060] In one embodiment, the step of obtaining target terminal voltage difference data corresponding to each single battery cell according to each terminal voltage data includes:

[0061] The terminal voltage data are normalized based on a preset normalization model to obtain the target terminal voltage difference data.

[0062] The preset normalization model may be a global normalization model. For example, the normalization process may be to perform difference processing on the terminal voltage data within the original range and then rescale the difference-processed data so that all processed target terminal voltage difference data are within the preset range.

[0063] By inputting the terminal voltage data into a preset normalization model for normalization processing, the target terminal pressure difference data is obtained, ensuring the consistency of the calculation process and results of the target terminal pressure difference data, simplifying the data processing process, reducing the amount of data calculation, and facilitating the subsequent steps of processing the target terminal pressure difference data.

[0064] In one embodiment, Figure 3 As shown, the steps of normalizing each terminal voltage data based on a preset normalization model to obtain each target terminal voltage difference data include:

[0065] Step S310: Obtain an average terminal voltage value based on each terminal voltage data.

[0066] The terminal voltage average value is obtained by averaging the terminal voltage data. For example, to further improve the accuracy of the terminal voltage average value, the maximum terminal voltage and the minimum terminal voltage can be removed from the terminal voltage data, and the remaining terminal voltage data can be averaged to obtain the terminal voltage average value.

[0067] Step S320 : performing difference processing on each terminal voltage data and the terminal voltage average value to obtain initial terminal voltage difference data of each single battery.

[0068] For example, each terminal voltage data is sequentially subjected to difference processing with the terminal voltage average value, and initial terminal voltage difference data corresponding to each single battery is obtained based on the processing result.

[0069] Step S330 : amplify and convert each initial terminal voltage difference data to obtain target terminal voltage data.

[0070] For example, based on a multiple of 1000, each initial terminal voltage difference data is amplified and converted to obtain the target terminal voltage data within the discharge range. That is, each initial terminal voltage difference data is multiplied by 1000, and the converted target terminal voltage data is at the mV (millivolt) level. This achieves normalization of the terminal voltage data, simplifies the data processing process, reduces the amount of data calculation, and facilitates the subsequent steps of judging and processing the target terminal voltage difference data. In this way, a corresponding balancing strategy is adopted for the battery system, ensuring the balance of the battery system's terminal voltage difference distribution during charge and discharge, thereby improving the charge and discharge capacity of the battery system.

[0071] In one embodiment, Figure 4 As shown, the steps of obtaining target capacity deviation data corresponding to each single battery according to each static voltage data include:

[0072] Step S410: According to each static voltage data, a preset voltage-capacity matching table is searched to obtain the remaining capacity data corresponding to each static voltage data.

[0073] The preset voltage-capacity matching table may be a Q-OCV matching table. It should be noted that Q refers to the remaining capacity (i.e., current capacity) of the corresponding single cell, and OCV (Open Circuit Voltage) refers to the open circuit voltage of the corresponding single cell, i.e., the voltage across the ends of the corresponding single cell when in a static state. For example, a preset voltage-capacity matching table may be pre-established based on historical test data. The preset voltage-capacity matching table may then be queried based on the static voltage data to obtain the remaining capacity data for each single cell.

[0074] Step S420: Obtain average capacity data based on the remaining capacity data.

[0075] The average capacity data is obtained by averaging the remaining capacity data. For example, in order to further improve the accuracy of the average capacity data, the maximum remaining capacity and the minimum remaining capacity of each remaining capacity data may be removed, and the remaining remaining capacity data may be averaged to obtain the average capacity data.

[0076] Step S430: Perform difference processing on each remaining capacity data and the average capacity data to obtain each target capacity deviation data.

[0077] For example, the remaining capacity data and the average capacity data are sequentially subjected to difference processing, and based on the processing results, the target capacity deviation data corresponding to each single battery is obtained, so that the subsequent steps can execute the corresponding balancing strategy based on the target capacity deviation data to ensure the balance of the voltage difference distribution of the battery system at the end of charge and discharge, thereby improving the charge and discharge capacity of the battery system and thus improving the service life of the battery system.

[0078] In one embodiment, the target terminal voltage difference data includes terminal charging voltage difference data and terminal discharging voltage difference data; the preset balancing conditions include the terminal charging voltage difference data being higher than a first charging threshold and the terminal discharging voltage difference data being higher than a first discharging threshold, the terminal charging voltage difference data being lower than a second charging threshold and the terminal discharging voltage difference data being lower than a second discharging threshold.

[0079] The terminal charge voltage difference data can be obtained by processing the corresponding terminal charge voltage data and the terminal charge voltage average; the terminal discharge voltage difference data can be obtained by processing the corresponding terminal discharge voltage data and the terminal discharge voltage average. It should be noted that the terminal voltage data includes the terminal charge voltage data and the terminal discharge voltage data; the terminal voltage average includes the terminal charge voltage average and the terminal discharge voltage average. The first charge threshold, the second charge threshold, the first discharge threshold, and the second discharge threshold can be pre-set. The first charge threshold is greater than or equal to the second charge threshold, and the first discharge threshold is greater than or equal to the second discharge threshold.

[0080] like Figure 5 As shown, the steps of performing a balancing action corresponding to a preset balancing condition on the battery to be balanced based on the target capacity deviation data include:

[0081] Step S510 : When the terminal charging voltage difference data is higher than a first charging threshold and the terminal discharging voltage difference data is higher than a first discharging threshold, a discharge balancing action is performed on the battery to be balanced based on corresponding target capacity deviation data.

[0082] By comparing the terminal charging voltage difference data with the first charging threshold, and comparing the terminal discharging voltage difference data with the first discharging threshold, when the terminal charging voltage difference data is higher than the first charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold, it is determined that the voltage difference of the corresponding single battery is too high at the charging and discharging ends, and then the corresponding discharge balancing action is selected, and based on the corresponding target capacity deviation data, the discharge balancing action is performed on the battery to be balanced, so as to achieve accurate and reliable balancing of each single battery in the battery system.

[0083] Step S520 : When the terminal charging voltage difference data is lower than a second charging threshold and the terminal discharging voltage difference data is lower than a second discharging threshold, a charge balancing action is performed on the battery to be balanced based on the corresponding target capacity deviation data.

[0084] By comparing the terminal charging voltage difference data with the second charging threshold, and comparing the terminal discharging voltage difference data with the second discharging threshold, when the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is lower than the second discharging threshold, it is determined that the voltage difference of the corresponding single battery is low at the charging and discharging terminals, and then the corresponding charging balancing action is selected. Based on the corresponding target capacity deviation data, the charging balancing action is performed on the battery to be balanced, thereby achieving accurate and reliable balancing of each single battery in the battery system, ensuring the balance of the voltage difference distribution of the battery system at the charging and discharging terminals, and improving the charging and discharging capacity of the battery system.

[0085] In one embodiment, the preset balancing condition further includes the terminal charging voltage difference data being higher than the first charging threshold and the terminal discharging voltage difference data being lower than the second discharging threshold, or the terminal charging voltage difference data being lower than the second charging threshold and the terminal discharging voltage difference data being higher than the first discharging threshold.

[0086] like Figure 6 As shown, the steps of performing a balancing action corresponding to a preset balancing condition on the battery to be balanced based on the target capacity deviation data include:

[0087] Step S610: When the terminal charging voltage difference data is higher than the first charging threshold and the terminal discharging voltage difference data is lower than the second discharging threshold, a discharge balancing operation is performed on the cells to be balanced based on the preset discharge balancing capacity until the difference between the next terminal charging voltage difference data and the next terminal discharging voltage difference data falls within the preset voltage difference threshold range.

[0088] The preset discharge balancing capacity can be set to 0.5Ah; and the preset voltage difference threshold range can be set to -10mV to 10mV.

[0089] By comparing the terminal charging voltage difference data with the first charging threshold and the second charging threshold, and comparing the terminal discharging voltage difference data with the first discharging threshold and the second discharging threshold, when the terminal charging voltage difference data is higher than the first charging threshold and the terminal discharging voltage difference data is lower than the second discharging threshold, it is determined that the voltage difference of the corresponding single battery is high at the charging end and low at the discharging end, and then the corresponding discharge balancing action is selected. Based on the preset discharge balancing capacity, the discharge balancing action is performed on the battery to be balanced, and the next terminal charging voltage difference data and terminal discharging voltage difference data of the corresponding single battery are obtained. Threshold judgment is performed on the terminal charging voltage difference data and the terminal discharging voltage difference data again until the difference between the next terminal charging voltage difference data and the next terminal discharging voltage difference data falls within the preset voltage difference threshold range. It is determined that the discharge balancing of the battery system is completed, thereby achieving accurate and reliable balancing of each single battery in the battery system.

[0090] Step S620: When the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold, charge balancing is performed on the cells to be balanced based on the preset charge balancing capacity until the difference between the next terminal charging voltage difference data and the next terminal discharging voltage difference data falls within the preset voltage difference threshold range.

[0091] Among them, the preset charge balancing capacity can be set to 0.5Ah.

[0092] By comparing the terminal charging voltage difference data with the first charging threshold and the second charging threshold, and comparing the terminal discharging voltage difference data with the first discharging threshold and the second discharging threshold, when the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold, it is determined that the voltage difference of the corresponding single battery is low at the charging end and high at the discharging end, and then the corresponding charge balancing action is selected. Based on the preset charge balancing power, the charge balancing action is performed on the battery to be balanced, and the next terminal charging voltage difference data and terminal discharging voltage difference data of the corresponding single battery are obtained. The threshold judgment is performed on the terminal charging voltage difference data and the terminal discharging voltage difference data again until the difference between the next terminal charging voltage difference data and the next terminal discharging voltage difference data falls within the preset voltage difference threshold range. It is determined that the charge balancing of the battery system is completed, and accurate and reliable balancing of each single battery in the battery system is achieved, further improving the charge and discharge capacity of the battery system.

[0093] In one embodiment, the terminal voltage data includes terminal charging voltage data and terminal discharging voltage data. The steps of obtaining the terminal voltage data of each single cell in the battery system include:

[0094] When the charging terminal current of the battery system reaches a first current threshold, the full-charge terminal voltage reaches a first voltage threshold, and the single-charge SOC (State of Charge) reaches a first SOC threshold, the terminal charging voltage data of each single battery is obtained; when the discharging terminal current of the battery system reaches a second current threshold, the full-discharge terminal voltage reaches a second voltage threshold, and the single-discharge SOC reaches a second SOC threshold, the terminal discharge voltage data of each single battery is obtained.

[0095] The terminal charging voltage data refers to the voltage data of the corresponding single cell at the end of charging; for example, the terminal charging voltage data is the voltage data most recently collected at the end of charging. The terminal discharging voltage data refers to the voltage data of the corresponding single cell at the end of discharging; for example, the terminal discharging voltage data is the voltage data most recently collected at the end of discharging.

[0096] The first current threshold can be set to 0.1C or 15A, etc. The first voltage threshold can be set according to the system charge cut-off voltage. For example, if the system charge cut-off voltage is 3.6V, the first voltage threshold is set to 3.57V. The first SOC threshold can be set to 70% SOC or 75% SOC, etc. The second current threshold can be set to the same as the first current threshold, such as the second current threshold is set to 0.1C or 15A, etc. The second voltage threshold can be set according to the system discharge cut-off voltage. For example, if the system discharge cut-off voltage is 2.8V, the second voltage threshold is set to 2.83V. The second SOC threshold can be set to the same as the first SOC threshold, such as the second SOC threshold is set to 70% SOC or 75% SOC, etc.

[0097] The charging terminal current of the battery system is compared with a first current threshold, the full charge terminal voltage is compared with a first voltage threshold, and the single charge SOC is compared with a first SOC threshold. Based on the comparison results, when the charging terminal current reaches the first current threshold, the full charge terminal voltage reaches the first voltage threshold, and the single charge SOC reaches the first SOC threshold, it is determined that the charging state of the battery system is in the charging terminal state, and then the terminal charging voltage of each single battery is collected to avoid shallow charging of the single battery, so as to accurately obtain the terminal charging voltage data of each single battery, and the data calculation amount is small, the data processing process is simple, and the balancing processing process in the subsequent steps is convenient, thereby improving the charging capacity of the battery system.

[0098] The end-of-discharge current of the battery system is compared with a second current threshold, the end-of-full-discharge voltage is compared with a second voltage threshold, and the single-discharge SOC is compared with a second SOC threshold. Based on the comparison results, when the end-of-discharge current reaches the second current threshold, the end-of-full-discharge voltage reaches the second voltage threshold, and the single-discharge SOC reaches the second SOC threshold, it is determined that the discharge state of the battery system is in the end-of-discharge state, and then the end-of-discharge voltage of each single battery is collected to avoid shallow discharge of the single battery, so as to accurately obtain the end-of-discharge voltage data of each single battery. In addition, the amount of data calculation is small, the data processing process is simple, and the balancing process in the subsequent steps is convenient, thereby increasing the discharge capacity of the battery system.

[0099] In one embodiment, the step of obtaining static voltage data of each single battery in the battery system includes:

[0100] When the discharge end current of the battery system reaches the third current threshold, the full discharge end voltage reaches the third voltage threshold, the single discharge SOC reaches the second SOC threshold, and the discharge end standby time reaches the preset time threshold, the static voltage data of each single battery is obtained.

[0101] The third current threshold can be set to 0.1C or 15A, etc. The third voltage threshold can be set according to the system discharge cut-off voltage. For example, if the system discharge cut-off voltage is 2.8V, the third voltage threshold is set to 2.83V. The third SOC threshold can be set to 70% SOC or 75% SOC, etc. The preset time threshold can be set between 1 hour and 3 hours.

[0102] When comparing the end-of-discharge current of the battery system with a third current threshold, the end-of-full-discharge voltage with a third voltage threshold, the single-discharge SOC with a third SOC threshold, and the end-of-discharge rest time with a preset time threshold, and based on the comparison results, when the end-of-discharge current reaches the third current threshold, the end-of-full-discharge voltage reaches the third voltage threshold, the single-discharge SOC reaches the third SOC threshold, and the end-of-discharge rest time reaches the preset time threshold, it is determined that the discharge state of the battery system is in a rest state after being discharged, and then the rest voltage of each single battery is collected to avoid shallow discharge of the single battery, while ensuring that each single battery is in a completely rest state, so as to accurately obtain the static voltage data of each single battery, with a small amount of data calculation and a simple data processing process, which is convenient for the balancing process in subsequent steps, thereby increasing the discharge capacity of the battery system.

[0103] It should be understood that although Figures 2 to 6The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figures 2 to 6 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0104] In one embodiment, a battery active balancing control device is provided, comprising:

[0105] The data acquisition unit is used to obtain the terminal voltage data and static voltage data of each single cell in the battery system.

[0106] The data processing unit is used to obtain target terminal voltage difference data corresponding to each single cell according to each terminal voltage data, and to obtain target capacity deviation data corresponding to each single cell according to each static voltage data.

[0107] The balancing processing unit is used to determine that the corresponding single cell is a cell to be balanced when the target terminal voltage difference data of any single cell meets the preset balancing condition, and perform a balancing action corresponding to the preset balancing condition on the cell to be balanced based on the target capacity deviation data.

[0108] The specific definition of the active battery balancing control device can be found in the definition of the active battery balancing control method above and will not be repeated here. Each module in the active battery balancing control device can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the modules can be embedded in or independent of the processor in the active battery balancing control system in hardware form, or can be stored in the memory of the active battery balancing control system in software form, so that the processor can call and execute the corresponding operations of each of the modules.

[0109] In one embodiment, Figure 1 As shown, a battery active balancing control system is also provided, including a processing device 100 and a battery system 200, the battery system 200 includes a plurality of single cells, and the processing device 100 is connected to each single cell 202; the processing device 100 is used to execute the steps of any one of the above-mentioned battery active balancing control methods.

[0110] For detailed description of the processing device 100 and the battery system 200 , please refer to the description of the above embodiments, which will not be repeated here.

[0111] Based on the processing device 100 being connected to each of the single cells 202, the processing device 100 obtains terminal voltage data and static voltage data of each of the single cells 202 in the battery system 200. Based on each of the terminal voltage data, the processing device 100 obtains target terminal voltage differential data corresponding to each of the single cells 202, and based on each of the static voltage data, obtains target capacity deviation data corresponding to each of the single cells 202. When the target terminal voltage differential data of any single cell 202 meets a preset balancing condition, the processing device 100 determines that the corresponding single cell 202 is a cell to be balanced, and performs a balancing action corresponding to the preset balancing condition on the cell to be balanced based on the target capacity deviation data, thereby achieving active balancing of each of the single cells 202 in the battery system 200.

[0112] In the above embodiment, by extracting the terminal voltage and static voltage of each single cell 202 in the battery system 200, calculating the terminal voltage difference corresponding to the terminal voltage, and calculating the capacity deviation corresponding to the static voltage, it is determined whether the single cell 202 meets the preset balancing condition, and adopting the corresponding charge and discharge balancing action to ensure the balance of the voltage difference distribution of the battery system 200 during charge and discharge, thereby improving the charge and discharge capacity of the battery system 200.

[0113] In one embodiment, a computer storage medium is further provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of any one of the above-mentioned battery active balancing control methods are implemented.

[0114] For example, when a computer program is executed by a processor, it performs the following steps:

[0115] The terminal voltage data and static voltage data of each single cell in the battery system are obtained; based on each terminal voltage data, target terminal voltage difference data corresponding to each single cell is obtained, and based on each static voltage data, target capacity deviation data corresponding to each single cell is obtained; when the target terminal voltage difference data of any single cell meets a preset balancing condition, the corresponding single cell is determined to be a cell to be balanced, and a balancing action corresponding to the preset balancing condition is performed on the cell to be balanced based on the target capacity deviation data, thereby achieving active balancing of each single cell in the battery system.

[0116] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned division operation methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), memory bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0117] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A battery active balancing control method, characterized in that: The following steps are involved: Obtain terminal voltage data and static voltage data of each single cell in the battery system; Obtaining target terminal voltage difference data corresponding to each of the single cells according to each of the terminal voltage data, and obtaining target capacity deviation data corresponding to each of the single cells according to each of the static voltage data; When the target terminal pressure difference data of any single battery meets a preset balancing condition, the corresponding single battery is determined to be a battery to be balanced, and a balancing action corresponding to the preset balancing condition is performed on the battery to be balanced based on the target capacity deviation data.

2. The battery active balancing control method according to claim 1, characterized in that: The step of obtaining target terminal voltage difference data corresponding to each of the single cells according to each of the terminal voltage data comprises: The terminal voltage data are normalized based on a preset normalization model to obtain the target terminal voltage difference data.

3. The battery active balancing control method according to claim 2, characterized in that: The step of normalizing the terminal voltage data based on a preset normalization model to obtain the target terminal voltage difference data includes: Obtaining an average terminal voltage value according to each of the terminal voltage data; performing difference processing on each of the terminal voltage data and the terminal voltage average value to obtain initial terminal voltage difference data of each of the single cells; Each of the initial terminal voltage difference data is amplified and converted to obtain the target terminal voltage data.

4. The battery active balancing control method according to claim 1, characterized in that: The step of obtaining target capacity deviation data corresponding to each of the single cells according to each of the static voltage data comprises: According to each of the static voltage data, querying a preset voltage-capacity matching table to obtain each of the remaining capacity data corresponding to the static voltage data; Obtaining average capacity data according to the remaining capacity data; Performing difference processing on each of the remaining capacity data and the average capacity data to obtain each of the target capacity deviation data.

5. The battery active balancing control method according to claim 1, characterized in that: The target terminal voltage difference data includes terminal charging voltage difference data and terminal discharging voltage difference data; the preset balancing condition includes that the terminal charging voltage difference data is higher than a first charging threshold and the terminal discharging voltage difference data is higher than a first discharging threshold, and the terminal charging voltage difference data is lower than a second charging threshold and the terminal discharging voltage difference data is lower than a second discharging threshold; The step of performing a balancing action corresponding to the preset balancing condition on the battery to be balanced based on the target capacity deviation data includes: When the terminal charging voltage difference data is higher than a first charging threshold and the terminal discharging voltage difference data is higher than a first discharging threshold, performing a discharge balancing action on the battery to be balanced based on the corresponding target capacity deviation data; When the terminal charging voltage difference data is lower than a second charging threshold and the terminal discharging voltage difference data is lower than a second discharging threshold, a charging balancing action is performed on the battery to be balanced based on the corresponding target capacity deviation data.

6. The battery active balancing control method according to claim 5, characterized in that: The preset balancing condition further includes that the terminal charging voltage difference data is higher than the first charging threshold and the terminal discharging voltage difference data is lower than the second discharging threshold, or the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold; The step of performing a balancing action corresponding to the preset balancing condition on the battery to be balanced based on the target capacity deviation data includes: When the terminal charge voltage difference data is higher than a first charge threshold and the terminal discharge voltage difference data is lower than a second discharge threshold, a discharge balancing action is performed on the battery to be balanced based on a preset discharge balancing capacity until a difference between the next terminal charge voltage difference data and the next terminal discharge voltage difference data falls within a preset voltage difference threshold range; When the terminal charging voltage difference data is lower than the second charging threshold and the terminal discharging voltage difference data is higher than the first discharging threshold, a charge balancing action is performed on the battery to be balanced based on the preset charge balancing power until the difference between the next terminal charging voltage difference data and the next terminal discharging voltage difference data falls within the preset voltage difference threshold range.

7. The battery active balancing control method according to any one of claims 1 to 6, characterized in that: The terminal voltage data includes terminal charging voltage data and terminal discharging voltage data; The step of obtaining the terminal voltage data of each single battery in the battery system includes: When the charging terminal current of the battery system reaches a first current threshold, the full charge terminal voltage reaches a first voltage threshold, and the single charge SOC reaches a first SOC threshold, acquiring terminal charging voltage data of each of the single batteries; When the discharge terminal current of the battery system reaches a second current threshold, the full discharge terminal voltage reaches a second voltage threshold, and the single discharge SOC reaches a second SOC threshold, the terminal discharge voltage data of each of the single batteries is obtained.

8. The battery active balancing control method according to any one of claims 1 to 6, characterized in that: The step of obtaining static voltage data of each single battery in the battery system includes: When the discharge end current of the battery system reaches the third current threshold, the full discharge end voltage reaches the third voltage threshold, the single discharge SOC reaches the second SOC threshold and the discharge end standby time reaches the preset time threshold, the static voltage data of each single battery is obtained.

9. A battery active balancing control system, characterized in that: The invention comprises a processing device and a battery system, wherein the battery system comprises a plurality of single cells, and the processing device is connected to each of the single cells; The processing device is used to execute the steps of the battery active balancing control method according to any one of claims 1 to 8.

10. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the battery active balancing control method according to any one of claims 1 to 8 are implemented.

Images