Battery passive equalization control method and system and storage medium

Abstract

The invention relates to a battery passive equalization control method and system and a storage medium. The method comprises the following steps: acquiring working state information of a battery system and first feature data of each single battery; screening a plurality of preset balance control modes according to the working state information and the first feature data to obtain a target balance control mode; based on the target equalization control mode, when the first feature data of the single batteries meet a preset equalization marking condition, marking the corresponding single batteries to obtain equalization marking information; according to the target equalization control mode and the equalization mark information, an equalization starting instruction is transmitted to the slave control module, so that the slave control module executes an equalization action on the corresponding single battery according to the equalization starting instruction, multi-mode equalization control is realized, the accuracy of equalization control is improved, excessive equalization or insufficient equalization is avoided, and the user experience is improved. The consistency of the single batteries in the battery system is effectively improved, and the equalization efficiency 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 passive balancing control method, system, and storage medium. Background Art

[0002] The passive balancing method of the BMS (Battery Management System) is to connect a balancing resistor and a control switch in parallel at both ends of the single battery. When the voltage of a single battery is too high, the corresponding control switch is closed and discharged through the corresponding balancing resistor to consume some energy, so that the voltage of the single battery tends to be consistent with the voltage of other single batteries.

[0003] In the existing BMS passive balancing control method, a single balancing strategy is usually used to start the passive balancing of the corresponding single battery, which can easily lead to over-balancing or under-balancing, affecting the accuracy of balancing. Summary of the Invention

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

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

[0006] Acquiring operating status information of the battery system and first characteristic data of each single battery in the battery system;

[0007] Filtering a plurality of preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode;

[0008] Based on the target balancing control mode, when the first characteristic data of the single battery meets the preset balancing marking condition, the corresponding single battery is marked to obtain balancing marking information;

[0009] According to the target balancing control mode and the balancing mark information, a balancing start instruction is generated and transmitted to the slave control module; the balancing start instruction is used to instruct the slave control module to perform a balancing action on the corresponding single battery.

[0010] In one embodiment, the step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0011] Screening the preset balancing control modes according to the working state information and the first characteristic data to obtain at least two preset balancing control modes;

[0012] The priorities of at least two preset balancing control modes are obtained, and based on the order of priority from high to low, the preset balancing control mode with the highest priority currently and in which balancing is not performed is determined as the target balancing control mode.

[0013] In one embodiment, the preset balancing control mode includes a charging end balancing mode; the working state information includes charging end state information; the first characteristic data includes a single cell voltage of a corresponding single cell;

[0014] The step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0015] When the working state information is charging end state information, at least one cell voltage is greater than a first cell voltage threshold, and at least one cell voltage is less than a second cell voltage threshold, the charging end balancing mode is determined as the target balancing control mode.

[0016] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0017] When the cell voltage is greater than a first cell voltage threshold, marking the corresponding cell to obtain balancing marking information;

[0018] The step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0019] According to the single cell voltage of each single cell, the average battery voltage is obtained;

[0020] When the battery average voltage is less than a first average voltage threshold, obtaining a first actual capacity of the marked single battery, and obtaining a target balancing time according to a first constant, a preset balancing current, and the first actual capacity;

[0021] When the battery average voltage is greater than or equal to the first average voltage threshold, obtaining a second actual capacity of the marked single battery, and obtaining a target balancing time according to a second constant, a preset balancing current, and the second actual capacity;

[0022] The steps of generating a balancing start instruction according to the target balancing control mode and the balancing mark information include:

[0023] Generate a balancing start instruction according to the target balancing control mode, balancing mark information and target balancing time.

[0024] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell and obtaining balancing marking information further includes:

[0025] According to the single cell voltage of each single cell, the minimum battery voltage is obtained;

[0026] When the lowest battery voltage is less than the second average voltage threshold, marking the single battery cells whose corresponding single battery voltages are greater than the first average voltage threshold to obtain balancing mark information;

[0027] Before the step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information, the step further includes:

[0028] When the lowest battery voltage is less than the second average voltage threshold and greater than or equal to the third average voltage threshold, obtaining a third actual capacity of the marked single battery, and obtaining a target balancing time based on a third constant, a preset balancing current, and the third actual capacity;

[0029] When the lowest battery voltage is less than the third average voltage threshold, the fourth actual capacity of the marked single battery is obtained, and the target balancing time is obtained according to the fourth constant, the preset balancing current and the fourth actual capacity.

[0030] In one embodiment, the preset balancing control mode includes a charging end-stage balancing mode; the working state information includes charging end-stage state information; the first characteristic data includes a single cell voltage of a corresponding single cell;

[0031] The step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0032] Get the charging current of the battery system;

[0033] According to the single cell voltage of each single cell, the maximum battery voltage is obtained;

[0034] When the working status information is charging end state information, the highest battery voltage is greater than the third single cell voltage threshold, the charging current is less than the first current threshold and the duration of the charging current reaches a preset time, the charging end balancing mode is determined as the target balancing control mode.

[0035] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0036] According to the single cell voltage of each single cell, the average battery voltage and the minimum battery voltage are obtained;

[0037] Obtaining a comparison voltage according to a preset voltage constant, an average battery voltage, and a minimum battery voltage;

[0038] When the cell voltage is greater than the comparison voltage, the corresponding cell is marked to obtain the balancing mark information;

[0039] The steps of generating a balancing start instruction according to the target balancing control mode and the balancing mark information include:

[0040] Set the preset initial time as the target balancing time;

[0041] Generate a balancing start instruction according to the target balancing control mode, balancing mark information and target balancing time.

[0042] In one embodiment, the preset balancing control mode includes a static linear region balancing mode; the working state information includes charging static state information; the first characteristic data includes a cell voltage of a corresponding single cell;

[0043] The step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0044] When the working state information is charging static state information and the cell voltages of the individual cells are all in the linear variation range of the preset OCV-SOC curve, the static linear region balancing mode is determined as the target balancing control mode.

[0045] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0046] Obtain the baseline remaining capacity of the battery system;

[0047] When the cell voltage meets the preset voltage condition, the actual battery capacity of the corresponding cell is obtained, and the comparative capacity is obtained based on the actual battery capacity and the reference remaining capacity;

[0048] When the remaining capacity of the corresponding single battery is greater than the comparison capacity, the corresponding single battery is marked to obtain balancing mark information;

[0049] The step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0050] Obtain the discharge capacity based on the benchmark remaining capacity and the remaining capacity of the corresponding single battery;

[0051] According to the capacity to be discharged and the preset balancing current, the target balancing time is obtained;

[0052] The steps of generating a balancing start instruction according to the target balancing control mode and the balancing mark information include:

[0053] Generate a balancing start instruction according to the target balancing control mode, balancing mark information and target balancing time;

[0054] Alternatively, a balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the capacity to be discharged.

[0055] In one embodiment, the preset balancing control mode includes a static nonlinear region balancing mode; the working state information includes charging static state information; the first characteristic data includes a cell voltage of a corresponding single cell;

[0056] The step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0057] When the working state information is charging static state information and the cell voltages of the individual cells are all in the nonlinear variation range of the preset OCV-SOC curve, the static nonlinear region balancing mode is determined as the target balancing control mode.

[0058] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0059] Obtain the reference voltage of the battery system;

[0060] When the difference between the single cell voltage and the reference voltage meets the preset threshold condition, the corresponding single cell is marked to obtain the balancing mark information;

[0061] The step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0062] When the difference between the cell voltage and the reference voltage is greater than a fourth cell voltage threshold, setting the first preset time as the target balancing time;

[0063] When the difference between the cell voltage and the reference voltage is greater than the fifth cell voltage threshold and less than the fourth cell voltage threshold, setting the second preset time as the target balancing time;

[0064] The steps of generating a balancing start instruction according to the target balancing control mode and the balancing mark information include:

[0065] Generate a balancing start instruction according to the target balancing control mode, balancing mark information and target balancing time.

[0066] In one embodiment, the step of obtaining the operating status information of the battery system and the first characteristic data of each single battery in the battery system includes:

[0067] Acquire second characteristic data of each single battery in the battery system;

[0068] The steps of obtaining the operating status information of the battery system and the first characteristic data of each single battery in the battery system include:

[0069] When each second characteristic data satisfies a preset balanced start condition, the working state information and each first characteristic data are acquired.

[0070] In one embodiment, each second characteristic data satisfies a preset equalization start condition, including:

[0071] Obtain battery system fault detection information, temperature data, total battery voltage and single cell voltage of each single cell;

[0072] When the fault detection information is non-fault information, the temperature data is less than a first preset temperature threshold, the lowest cell voltage among the cell voltages is less than a first balancing voltage threshold, and the difference between the sum of the cell voltages and the total battery voltage is less than a first preset voltage threshold, it is determined that each second characteristic data satisfies a preset balancing start condition.

[0073] In one embodiment, the steps are further included:

[0074] When the fault detection information is fault information, the temperature data is greater than or equal to the first preset temperature threshold, the lowest cell voltage among the single cell voltages is less than the second balancing voltage threshold, or the difference between the sum of the single cell voltages and the total battery voltage is greater than the second preset voltage threshold, a balancing interruption instruction is transmitted to the slave control module; the balancing interruption instruction is used to instruct the slave control module to stop performing balancing operations on the corresponding single cell.

[0075] In one embodiment, the step of transmitting the equalization start instruction to the slave control module includes:

[0076] Get the temperature of the balancing plate of the battery system;

[0077] When the equalizing plate temperature is greater than or equal to the second preset temperature threshold, polling and transmitting an equalizing start instruction based on the first preset time length and an equalizing stop instruction based on the second preset time length to the slave control module until the next obtained equalizing plate temperature is less than the third preset temperature threshold;

[0078] When the temperature of the balancing plate is lower than a third preset temperature threshold, a balancing start instruction is transmitted to the slave control module.

[0079] In a second aspect, the present application further provides a battery passive balancing control system, comprising a master control module, a plurality of slave control modules, and a battery system, wherein the battery system comprises a plurality of single cells, the master control module is connected to each of the slave control modules, and the slave control module is connected to at least one single cell;

[0080] The main control module is used to execute any one of the steps of the above-mentioned battery passive balancing control method.

[0081] 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 passive balancing control methods when the computer program is executed by a processor.

[0082] One of the above technical solutions has the following advantages and beneficial effects:

[0083] In the above-mentioned battery passive balancing control method, the working status information of the battery system and the first characteristic data of each single cell in the battery system are obtained; based on the working status information and each first characteristic data, multiple preset balancing control modes are screened to obtain a target balancing control mode; based on the target balancing control mode, when the first characteristic data of the single cell meets the preset balancing marking condition, the corresponding single cell is marked to obtain balancing marking information; based on the target balancing control mode and the balancing marking information, a balancing start instruction is generated and transmitted to the slave control module; the balancing start instruction is used to instruct the slave control module to perform a balancing action on the corresponding single cell, thereby realizing multi-mode balancing control. This application selects the optimal preset balancing control mode as the target balancing control mode based on the working status information and the first characteristic data of each single cell, and determines the balancing marking information based on the target balancing control mode, and then performs balancing control on the corresponding single cell based on the target balancing control mode and the balancing marking information, thereby improving the accuracy of balancing control, diversifying the balancing control strategy, avoiding over-balancing or under-balancing, effectively improving the consistency of the single cells in the battery system, and improving the efficiency of battery system balancing. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 Schematic diagram of the application environment of the battery passive balancing control method in an embodiment of the present application;

[0085] Figure 2 This is a schematic diagram of a first flow chart of a battery passive balancing control method according to an embodiment of the present application;

[0086] Figure 3 Schematic diagram of the process of selecting the priority of the target balancing control mode in the embodiment of the present application;

[0087] Figure 4 This is a first flow chart of the target balancing time acquisition step in an embodiment of the present application;

[0088] Figure 5 Schematic diagram of the process of screening the equalization mode at the end of charging in an embodiment of the present application;

[0089] Figure 6Schematic diagram of the flow of the steps for obtaining equalization mark information in the static linear region equalization mode in an embodiment of the present application;

[0090] Figure 7 This is a second flow chart of the target balancing time acquisition step in an embodiment of the present application;

[0091] Figure 8 This is a flow chart of the step of determining the equalization start condition in the embodiment of the present application;

[0092] Figure 9 Schematic diagram of the process of adjusting the temperature of the equalizing plate in the embodiment of the present application. DETAILED DESCRIPTION

[0093] 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.

[0094] 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.

[0095] Additionally, the term "plurality" shall mean two or more.

[0096] 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.

[0097] The battery passive balancing control method provided in this application can be applied to Figure 1In the application environment shown, a battery system 300 includes multiple single cells 302, and a processing device is connected to each single cell 302. The processing device may include a master control module 100 and multiple slave control modules 200. The master control module 100 is connected to each slave control module 200, and each slave control module 200 is connected to at least one single cell 302. The slave control module 200 may include a slave control unit (VCMU, Voltage Cell Monitoring Unit), multiple balancing switches, and multiple balancing resistors. The slave control module 200 is used to receive balancing start instructions from the master control module 100 and control the balancing on and off of the corresponding single cell 302. It should be noted that each single cell 302 is connected in parallel with a balancing resistor and a balancing switch. The master control module 100 may include a master control unit (SBMU, Smart Battery Management Unit), which is connected to the slave control units. The master control unit is responsible for executing overall balancing strategy decisions, balancing mode selection, balancing time calculation, command issuance, and status monitoring. The main control module 100 also includes a memory and a sensor module, each of which is connected to the main control unit. The memory may be, but is not limited to, an EEPROM and can be used to store information such as operating status information, first characteristic data, preset balancing control mode, target balancing control mode, and balancing flag information. The sensor module may include a single cell 302 voltage sensor, a total voltage sensor, a current sensor, a battery temperature sensor, and a balancing board temperature sensor. The single cell 302 voltage sensor is used to detect the single cell 302 voltage of the corresponding single cell 302; the total voltage sensor is used to detect the total voltage of the battery system 300; the current sensor is used to detect the total current of the battery system 300; the battery temperature sensor is used to detect the temperature of the corresponding single cell 302; and the balancing board temperature sensor is used to detect the balancing board temperature. The master control module 100 can be used to obtain operating status information of the battery system 300 and first characteristic data of each battery cell 302 in the battery system 300; based on the operating status information and each first characteristic data, screen multiple preset balancing control modes to obtain a target balancing control mode; based on the target balancing control mode, when the first characteristic data of a battery cell 302 meets a preset balancing marking condition, mark the corresponding battery cell 302 to obtain balancing marking information; based on the target balancing control mode and the balancing marking information, generate a balancing start instruction and transmit the balancing start instruction to the slave control module 200; the balancing start instruction is used to instruct the slave control module 200 to perform balancing operations on the corresponding battery cell 302. Exemplarily, the processing device can be a battery management system (BMS).

[0098] In one embodiment, Figure 2As shown, a battery passive balancing control method is also provided, which is applied to Figure 1 The main control module shown in the figure is used as an example to illustrate the following steps:

[0099] Step S210: Acquire the operating status information of the battery system and the first characteristic data of each single battery in the battery system.

[0100] Among them, the battery system can be a lithium battery system, the battery system can include multiple single cells, each single cell can be connected in series and / or parallel, the single cell can be a lithium-ion battery, and the shape of the single cell can be square or cylindrical, etc.

[0101] The operating status information refers to the operating status information of the battery system in different operating stages; for example, the different operating stages may be the charging end stage, the charging end stage, the fully rested stage, etc. The first characteristic data refers to the voltage data or current data of the single battery in the corresponding operating state.

[0102] For example, the main control module detects the working state of the battery system to obtain the working state information of the corresponding battery system; the main control module performs feature detection on each single battery in the corresponding working state to obtain the first feature data of each single battery.

[0103] Step S220 : Filter multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode.

[0104] Among them, the preset balancing control mode can be obtained according to the system preset.

[0105] For example, the preset balancing control mode is pre-stored in the memory. The main control module queries the preset balancing control modes in the memory based on the acquired working status information and each first characteristic data, selects the preset balancing control mode with the best matching degree from each preset balancing control mode, and determines the selected preset balancing control mode as the target balancing control mode.

[0106] Step S230 : Based on the target balancing control mode, when the first characteristic data of the single battery cell meets the preset balancing marking condition, the corresponding single battery cell is marked to obtain balancing marking information.

[0107] The preset balancing marking conditions are preset based on the different operating conditions of the battery system. The balancing marking information can be a numeric marking code and / or an alphabetic marking code; the balancing marking information is used to indicate the cells in the battery system that require balancing control. It should be noted that the balancing marking information can be stored in a memory.

[0108] For example, the main control module selects a corresponding preset balancing marking condition according to the target balancing control mode, and compares the first characteristic data with the corresponding preset balancing marking condition. When the first characteristic data of the single cell meets the preset balancing marking condition, it is determined that the corresponding single cell needs to be passively balanced, and then the corresponding single cell is marked to obtain balancing marking information.

[0109] Step S240 : Generate a balancing start instruction according to the target balancing control mode and the balancing mark information, and transmit the balancing start instruction to the slave control module; the balancing start instruction is used to instruct the slave control module to perform a balancing operation on the corresponding single battery.

[0110] The balancing start instruction may include balancing mark information and balancing control information of the corresponding single battery, for example, balancing control information may include balancing time information or balancing capacity information.

[0111] For example, the master control module generates a balancing start instruction based on the currently activated target balancing control mode and balancing mark information, and sends the balancing start instruction to the corresponding slave control module. The slave control module turns on the balancing switch of the single cell to be balanced according to the received balancing start instruction, and the corresponding single cell discharges through the balancing resistor to achieve precise balancing adjustment of the corresponding single cell of the battery system.

[0112] In the above-mentioned embodiment, the working status information of the battery system and the first characteristic data of each single cell in the battery system are obtained; based on the working status information and each first characteristic data, multiple preset balancing control modes are screened to obtain a target balancing control mode; based on the target balancing control mode, when the first characteristic data of the single cell meets the preset balancing marking condition, the corresponding single cell is marked to obtain balancing marking information; based on the target balancing control mode and the balancing marking information, a balancing start instruction is generated and transmitted to the slave control module; the slave control module performs balancing actions on the corresponding single cell according to the balancing start instruction, thereby realizing multi-mode balancing control. The present application selects the optimal preset balancing control mode as the target balancing control mode based on the working status information and the first characteristic data of each single cell, and determines the balancing marking information based on the target balancing control mode, and then performs balancing control on the corresponding single cell based on the target balancing control mode and the balancing marking information, thereby improving the accuracy of balancing control, diversifying the balancing control strategy, avoiding over-balancing or under-balancing, effectively improving the consistency of the single cells in the battery system, and improving the efficiency of battery system balancing.

[0113] In one embodiment, Figure 3 As shown, the steps of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain the target balancing control mode include:

[0114] Step S310: Screen the preset balancing control modes according to the working state information and the first characteristic data to obtain at least two preset balancing control modes.

[0115] The balancing modes within each preset balancing control mode are different; for example, each preset balancing control mode may include a charge end balancing mode, a charge end balancing mode, a static linear region balancing mode, and a static nonlinear region balancing mode. The priority of each preset balancing control mode can be pre-set by the system. For example, the priority of the charge end balancing mode, the charge end balancing mode, the static linear region balancing mode, and the static nonlinear region balancing mode decreases in order.

[0116] Step S320: Obtain the priorities of at least two preset balancing control modes, and determine the preset balancing control mode with the highest priority and not performing balancing as the target balancing control mode based on the order of priority from high to low.

[0117] For example, the main control module screens each preset balancing control mode based on the operating status information and the first characteristic data of each cell. If at least one cell is found to meet one of the preset balancing control modes and at least one cell meets another preset balancing control mode, then, based on the priority order of the preset balancing control modes, the currently highest-priority preset balancing control mode that has not yet been balanced is determined as the target balancing control mode, and balancing is performed on the corresponding cell based on the target balancing control mode. After balancing is completed on the corresponding cell, the next-highest-priority preset balancing control mode that has not yet been balanced is determined as the target balancing mode, and balancing is performed on the corresponding cell based on the newly determined target balancing control mode. This ensures that balancing is performed on the corresponding cells according to the priority of the preset balancing control modes. Only after balancing is completed on the cell corresponding to the higher-priority balancing control mode is a lower-priority balancing control mode triggered. This clarifies the execution priorities of different balancing control modes, ensuring that the most effective balancing is performed at the critical moment when the battery most needs balancing (e.g., when charging is about to be completed), thereby improving the effectiveness and timeliness of battery balancing.

[0118] In one embodiment, the preset balancing control mode includes a charging end balancing mode; the working state information includes charging end state information; and the first characteristic data includes a cell voltage of a corresponding single cell.

[0119] The end-of-charge balancing mode is the highest priority balancing control mode. The end-of-charge status information refers to the battery system's end-of-charge state. Cell voltages can be detected by corresponding cell voltage sensors. For example, if the battery system's operating status information indicates the end of charge and a cell voltage meets a preset voltage condition, the end-of-charge balancing mode is triggered.

[0120] In one example, the step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0121] When the working state information is charging end state information, at least one cell voltage is greater than a first cell voltage threshold, and at least one cell voltage is less than a second cell voltage threshold, the charging end balancing mode is determined as the target balancing control mode.

[0122] For example, when a battery system is connected to a charger and the battery system is fully charged or the charging current drops to a predetermined value close to the cutoff value, the charger sends a full charge signal to the main control module. The main control module then determines, based on the full charge signal, that the operating status information of the battery system is charging termination information. The first cell voltage threshold is greater than the second cell voltage threshold. For example, the first cell voltage threshold can be set to 3.55V, and the second cell voltage threshold can be set to 3.45V.

[0123] The main control module detects the working status information of the battery system. If the working status information is detected as charging end status information, it further determines whether there is at least one cell voltage greater than a first cell voltage threshold and at the same time at least one cell voltage less than a second cell voltage threshold. If both exist, the charging end balancing mode is triggered and the charging end balancing mode is determined as the target balancing control mode.

[0124] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0125] When the cell voltage is greater than the first cell voltage threshold, the corresponding cell is marked to obtain balancing mark information.

[0126] For example, the main control module compares the voltage of each cell with the first cell voltage threshold according to the triggered end-of-charge balancing mode. If there is a cell voltage greater than the first cell voltage threshold, the corresponding cell is marked to obtain balancing marking information, thereby marking all cells with cell voltages greater than the first cell voltage threshold, so that the corresponding cells are determined as cells to be balanced.

[0127] In one example, if Figure 4As shown, the step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information includes:

[0128] Step S410: Obtain the average battery voltage according to the cell voltage of each cell.

[0129] When the main control module triggers the charge end equalization mode, it processes the average value of each cell voltage to obtain the average battery voltage of the battery system.

[0130] Step S420: When the average battery voltage is less than a first average voltage threshold, obtain the first actual capacity of the marked single battery, and obtain a target balancing time according to a first constant, a preset balancing current, and the first actual capacity.

[0131] The first average voltage threshold can be set to 3.5V. The preset balancing current can be obtained based on system settings. The first actual capacity refers to the actual capacity of the corresponding single cell, for example, by performing a capacity test on the corresponding single cell. The first constant can be set to 0.7%.

[0132] For example, the main control module compares the average battery voltage with a first average voltage threshold. If the average battery voltage is less than the first average voltage threshold, the main control module obtains the first actual capacity of the marked single battery and processes the first constant, the preset balancing current, and the first actual capacity based on the first balancing time model to obtain the target balancing time. For example, if the first constant is A1, the preset balancing current is I, the first actual capacity is C1, and the target balancing time is T, then the first balancing time model is: T = A1 * C1 / I.

[0133] Step S430: When the battery average voltage is greater than or equal to the first average voltage threshold, obtain the second actual capacity of the marked single battery, and obtain the target balancing time according to the second constant, the preset balancing current and the second actual capacity.

[0134] The second actual capacity refers to the actual capacity of the corresponding single battery, for example, the second actual capacity is obtained by performing a capacity test on the corresponding single battery. The second constant can be set to 0.5%.

[0135] For example, the main control module compares the average battery voltage with a first average voltage threshold. If the average battery voltage is greater than or equal to the first average voltage threshold, the main control module obtains the second actual capacity of the marked single battery and processes the second constant, the preset balancing current, and the second actual capacity based on the second balancing time model to obtain the corresponding target balancing time. For example, if the second constant is set to A2, the preset balancing current is set to I, the second actual capacity is set to C2, and the target balancing time is set to T, then the second balancing time model is: T = A2 * C2 / I.

[0136] For example, the minimum battery voltage can be obtained based on the minimum value of each cell voltage. When the minimum battery voltage is less than the second average voltage threshold and the cell voltage is greater than the first cell voltage threshold, the corresponding cell is marked to obtain balancing marking information. When the minimum battery voltage is less than the second average voltage threshold and the battery average voltage is less than the first average voltage threshold, the target balancing time is obtained by processing the first constant, the preset balancing current, and the first actual capacity based on the first balancing time model. When the minimum battery voltage is less than the second average voltage threshold and the battery average voltage is greater than or equal to the first average voltage threshold, the target balancing time is obtained by processing the second constant, the preset balancing current, and the second actual capacity based on the second balancing time model. It should be noted that the second average voltage threshold is less than the first average voltage threshold and can be set to 3.45V.

[0137] In the above example, the triggered end-of-charge balancing mode avoids under- or over-balancing that may result from traditional fixed durations or simple threshold judgments by dynamically calculating the balancing time, thereby minimizing unnecessary energy loss, optimizing the balancing time, and improving balancing efficiency.

[0138] In one example, the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0139] Generate a balancing start instruction according to the target balancing control mode, balancing mark information and target balancing time.

[0140] For example, the master control module generates a balancing start instruction based on the balancing mark information, target balancing time and the currently activated end-of-charge balancing mode, and sends the balancing start instruction to the corresponding slave control module. The slave control module turns on the balancing switch of the single cell to be balanced according to the received balancing start instruction, and the corresponding single cell discharges through the balancing resistor to achieve precise balancing adjustment of the corresponding single cell of the battery system, effectively improving the consistency of the single cells in the battery system, thereby improving the overall available capacity and energy utilization efficiency of the battery system.

[0141] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information further includes:

[0142] The lowest battery voltage is obtained according to the cell voltage of each cell; when the lowest battery voltage is less than the second average voltage threshold, the cells whose corresponding cell voltages are greater than the first average voltage threshold are marked to obtain balancing mark information.

[0143] The second average voltage threshold may be set to 3.45V.

[0144] The main control module screens the minimum value among the cell voltages to obtain the lowest cell voltage. Based on the end-of-charge balancing mode, the main control module compares the lowest cell voltage with a threshold. When the lowest cell voltage is less than the second average voltage threshold, the main control module marks the cells with cell voltages greater than the first average voltage threshold as cells to be balanced, thereby obtaining balancing marking information for the cells to be balanced.

[0145] In one example, before the step of generating the balancing start instruction according to the target balancing control mode and the balancing flag information, the step further includes:

[0146] When the lowest cell voltage is less than the second average voltage threshold and greater than or equal to the third average voltage threshold, the third actual capacity of the marked single cell is obtained, and the target balancing time is obtained based on the third constant, the preset balancing current, and the third actual capacity. When the lowest cell voltage is less than the third average voltage threshold, the fourth actual capacity of the marked single cell is obtained, and the target balancing time is obtained based on the fourth constant, the preset balancing current, and the fourth actual capacity.

[0147] The third average voltage threshold is lower than the second average voltage threshold; for example, the third average voltage threshold can be set to 3.39 V. The third actual capacity and the fourth actual capacity refer to the actual capacity of the corresponding single battery. The third constant can be set to 1%, and the fourth constant can be set to 2%.

[0148] For example, based on the end-of-charge balancing mode, the main control module compares the lowest cell voltage with a threshold. Based on the comparison result, if the lowest cell voltage is less than the second average voltage threshold and greater than or equal to the third average voltage threshold, the main control module obtains the third actual capacity of the marked single cell and processes the third constant, the preset balancing current, and the third actual capacity based on the third balancing time model to obtain a target balancing time. If the lowest cell voltage is less than the third average voltage threshold, the main control module obtains the fourth actual capacity of the marked single cell and processes the fourth constant, the preset balancing current, and the fourth actual capacity based on the fourth balancing time model to obtain a corresponding target balancing time. For example, if the third constant is set to A3, the preset balancing current is set to I, and the third actual capacity is set to C3, and the target balancing time is T, then the third balancing time model is: T = A3 * C3 / I. If the fourth constant is set to A4, the preset balancing current is set to I, and the fourth actual capacity is set to C4, and the target balancing time is T, then the fourth balancing time model is: T = A4 * C4 / I.

[0149] In the above example, based on the dynamic and accurate calculation of the battery balancing time in the end-of-charge balancing mode, energy utilization is optimized, unnecessary energy consumption is avoided, the SOC of each single cell in the battery system is made more consistent, the overall available capacity of the battery system is improved, the voltage and SOC differences between single cells are reduced, and some batteries are prevented from being in a state of overcharge or over-discharge edge for a long time, thereby slowing down battery aging and extending the cycle life of the battery system.

[0150] In one embodiment, the preset balancing control mode includes a charging end-stage balancing mode; the working state information includes charging end-stage state information; and the first characteristic data includes a cell voltage of a corresponding single cell.

[0151] The final charge equalization mode has a lower priority than the end-of-charge equalization mode. The final charge status information refers to the battery system's final charge state. For example, if the battery system's operating status information is in the final charge state and a single cell voltage meets a preset voltage condition, the final charge equalization mode is triggered.

[0152] like Figure 5 As shown, the steps of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain the target balancing control mode include:

[0153] Step S510: Obtain the charging current of the battery system.

[0154] The charging current of the battery system can be detected by a current sensor to obtain the charging current of the battery system.

[0155] Step S520: Obtain the highest battery voltage according to the single cell voltages of the single cells.

[0156] The main control module obtains the corresponding maximum battery voltage by screening the maximum value of each single cell voltage.

[0157] Step S530: When the working status information is charging end state information, the highest battery voltage is greater than the third cell voltage threshold, the charging current is less than the first current threshold, and the duration of the charging current reaches a preset time, the charging end balancing mode is determined as the target balancing control mode.

[0158] Among them, the third single-cell voltage threshold is less than the first single-cell voltage threshold, the third single-cell voltage threshold can be set to 3.4V, the first current threshold can be set to 0.35C, and the preset time can be set to 1min.

[0159] The main control module detects the working status information of the battery system. If the working status information is detected as the final charging status information, it further determines whether the highest battery voltage among the single cell voltages is greater than the third single cell voltage threshold, and whether the charging current is less than the first current threshold and the duration reaches a preset time. If all of these conditions are met, the final charging balancing mode is triggered, and the final charging balancing mode is determined as the target balancing control mode. By selecting the optimal target balancing control mode, the balancing is made more accurate, which effectively improves the consistency of the single cells in the battery system, thereby improving the overall available capacity and energy utilization efficiency of the battery system.

[0160] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0161] According to the cell voltage of each single cell, the battery average voltage and the minimum cell voltage are obtained; according to the preset voltage constant, the battery average voltage and the minimum cell voltage, the comparison voltage is obtained; when the cell voltage is greater than the comparison voltage, the corresponding single cell is marked to obtain the balance mark information.

[0162] The voltage constant can be set to 20mV. For example, if the comparison voltage is set to Ub, the average voltage is Ua, the minimum battery voltage is Vmin, and the voltage constant is B, the comparison voltage can be calculated using the following formula: Ub = (Ua + Vmin) / 2 + B.

[0163] For example, upon triggering the end-of-charge balancing mode, the main control module compares each cell voltage with a comparison voltage. If a cell voltage is greater than the comparison voltage, the corresponding cell is marked to obtain balancing flag information, thereby identifying the corresponding cell as a cell to be balanced. It should be noted that the balancing flag information in this end-of-charge balancing mode is only valid at the end of the charge cycle.

[0164] In one example, the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0165] The preset initial time is set as the target balancing time; and a balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the target balancing time.

[0166] The preset initial time can be obtained according to the system preset, for example, the preset initial time can be set to 3 minutes.

[0167] Based on the triggered end-of-charge balancing mode, the master control module sets the preset initial time as the target balancing time, and then generates a balancing start instruction according to the corresponding balancing mark information, target balancing time and end-of-charge balancing mode, and sends the balancing start instruction to the corresponding slave control module. The slave control module executes the balancing action of the corresponding target balancing time according to the received balancing start instruction. If the target balancing time is reached, it re-evaluates whether it needs to continue the execution until the balancing adjustment of the battery system in the end-of-charge balancing mode is completed, so as to achieve precise balancing adjustment of the corresponding single cells of the battery system, effectively improve the consistency of the single cells in the battery system, and allow the entire battery system to charge more electricity, thereby improving the overall available capacity and energy utilization efficiency of the battery system, extending the overall life of the battery system, and reducing the replacement frequency of the battery system and related maintenance costs.

[0168] In one embodiment, the preset balancing control mode includes a static linear region balancing mode; the working state information includes charging static state information; and the first characteristic data includes a cell voltage of a corresponding single cell.

[0169] The static linear region balancing mode has a lower priority than the final charge balancing mode. Charging static state information refers to information indicating that the battery system is in a fully static state. For example, when the battery system is in a fully static state and a single cell voltage meets a preset voltage condition, the static linear region balancing mode is triggered.

[0170] In one example, the step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0171] When the working state information is charging static state information and the cell voltages of the individual cells are all in the linear variation range of the preset OCV-SOC curve, the static linear region balancing mode is determined as the target balancing control mode.

[0172] The preset OCV-SOC curve represents the open circuit voltage at different SOCs. It should be noted that OCV (Open Circuit Voltage) refers to the open circuit voltage, and SOC (State of Charge) refers to the remaining capacity. The preset OCV-SOC curve can be divided into a linear range and a nonlinear range based on the curve changes. For example, the voltage range of the linear range can be between 2.5V and 3.27V.

[0173] For example, the main control module detects the working status information of the battery system. If it is detected that the absolute value of the current of the battery system is less than 0.1C and lasts for 1 hour, it is determined that the battery system is in a fully static state, that is, the working status information is determined to be charging static state information, and then it is further determined whether the cell voltage of each single battery is in the linear change range of the preset OCV-SOC curve. If all single batteries are in the linear change range of the preset OCV-SOC curve, the static linear area balancing mode is triggered, and the static linear area balancing mode is determined as the target balancing control mode. By selecting the optimal target balancing control mode, the balancing is made more accurate, which effectively improves the consistency of the single batteries in the battery system, thereby improving the overall available capacity and energy utilization efficiency of the battery system.

[0174] In one embodiment, Figure 6 As shown, when the first characteristic data of a single cell meets a preset balancing marking condition, the corresponding single cell is marked to obtain balancing marking information, including the following steps:

[0175] Step S610: Obtain the baseline remaining capacity of the battery system.

[0176] The reference remaining capacity may be obtained by acquiring the lowest remaining capacity of corresponding single cells in the battery system. The reference remaining capacity may also be obtained by averaging the remaining capacities of the voltages of the individual cells.

[0177] Step S620: When the cell voltage meets the preset voltage condition, the actual battery capacity of the corresponding cell is obtained, and the comparative capacity is obtained according to the actual battery capacity and the reference remaining capacity.

[0178] Among them, the preset voltage condition can be determined based on the lowest cell voltage in the battery system. For example, the preset voltage condition can be set to whether the cell voltage is higher than the lowest cell voltage + 0.005V. When the cell voltage is higher than the lowest cell voltage + 0.005V, it is determined that the corresponding cell voltage meets the preset voltage condition.

[0179] For example, assuming the reference remaining capacity is Q1, the actual battery capacity is Q2, and the comparative capacity is Qb, the calculation formula for the comparative capacity is: Qb=Q1+1.5%*Q2.

[0180] Step S630: When the remaining capacity of the corresponding single battery is greater than the comparison capacity, the corresponding single battery is marked to obtain balancing mark information.

[0181] Based on the static linear region balancing mode, the main control module obtains the remaining capacity of the corresponding single cell and compares the remaining capacity with the comparison capacity. When the corresponding remaining capacity is greater than the comparison capacity, the corresponding single cell is marked to obtain balancing mark information to determine the corresponding single cell as a battery to be balanced.

[0182] In one example, the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0183] The to-be-discharged capacity is obtained based on the reference remaining capacity and the remaining capacity of the corresponding single battery; the target balancing time is obtained based on the to-be-discharged capacity and the preset balancing current;

[0184] The capacity to be discharged refers to the capacity of the battery to be balanced that needs to be discharged.

[0185] Based on the static linear region balancing mode, the main control module obtains the capacity to be discharged by subtracting the benchmark remaining capacity from the remaining capacity of the corresponding single battery; and obtains the target balancing time by dividing the capacity to be discharged by the preset balancing current, thereby realizing dynamic calculation of the balancing time in the static linear region balancing mode. This avoids the under- or over-balancing that may result from traditional fixed time lengths or simple threshold judgments, and minimizes unnecessary energy loss.

[0186] In one example, the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes:

[0187] A balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the target balancing time; or a balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the capacity to be discharged.

[0188] Among them, the balance start instruction can be generated according to the static linear region balance mode, balance mark information and target balance time; the balance start instruction can be generated according to the static linear region balance mode, balance mark information and standby capacity.

[0189] The master control module sends a corresponding balancing start instruction to the corresponding slave control module, and the slave control module performs the balancing action of the corresponding target balancing time according to the received balancing start instruction; the master control module can also perform the balancing action of the corresponding to-be-discharged capacity according to the received balancing start instruction to achieve precise balancing adjustment of the corresponding single cells in the battery system, effectively improving the consistency of the single cells in the battery system and improving the overall available capacity and energy utilization efficiency of the battery system.

[0190] In one embodiment, the preset balancing control mode includes a static nonlinear region balancing mode; the working state information includes charging static state information; and the first characteristic data includes a cell voltage of a corresponding single cell.

[0191] The priority of the static nonlinear region balancing mode is lower than that of the static linear region balancing mode. For example, when the battery system is in a fully static state and the cell voltage meets the corresponding preset voltage condition, the static nonlinear region balancing mode is triggered.

[0192] In one example, the step of screening multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode includes:

[0193] When the working state information is charging static state information and the cell voltages of the individual cells are all in the nonlinear variation range of the preset OCV-SOC curve, the static nonlinear region balancing mode is determined as the target balancing control mode.

[0194] For example, the main control module detects the working status information of the battery system. If the working status information is detected as charging static state information, it further determines whether the single cell voltage of each single cell is in the nonlinear change range of the preset OCV-SOC curve. If all single cells are in the nonlinear change range of the preset OCV-SOC curve, the static nonlinear area balancing mode is triggered, and the static nonlinear area balancing mode is determined as the target balancing control mode. By selecting the optimal target balancing control mode, the balancing is made more accurate, the balancing control strategy is diversified, and the consistency of the single cells in the battery system is effectively improved, thereby improving the overall available capacity and energy utilization efficiency of the battery system.

[0195] In one embodiment, when the first characteristic data of a single battery cell meets a preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information includes:

[0196] Obtain a reference voltage for the battery system; when the difference between the cell voltage and the reference voltage meets a preset threshold condition, mark the corresponding cell to obtain balancing mark information.

[0197] For example, the average battery voltage and the lowest battery voltage of the battery system may be obtained, and the reference voltage of the battery system may be obtained by averaging the average battery voltage and the lowest battery voltage.

[0198] The preset threshold adjustment can be based on whether the difference between the cell voltage and the reference voltage is greater than a preset threshold (e.g., 15mV). For example, based on the static nonlinear region balancing mode, when the difference between the cell voltage and the reference voltage is greater than 15mV, the main control module determines that the difference between the cell voltage and the reference voltage meets the preset threshold condition, and then marks the corresponding cell to obtain balancing mark information, thereby identifying the corresponding cell as a cell to be balanced.

[0199] like Figure 7As shown, the step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information includes:

[0200] Step S710 : When the difference between the cell voltage and the reference voltage is greater than a fourth cell voltage threshold, setting the first preset time as the target balancing time.

[0201] The fourth cell voltage threshold may be set to 30 mV, and the first preset time may be set to 20 hours.

[0202] The main control module compares the difference between the cell voltage and the reference voltage based on the static nonlinear region balancing mode. If the difference between the cell voltage and the reference voltage is greater than the fourth cell voltage threshold, the first preset time is set as the target balancing time.

[0203] Step S720 : When the difference between the cell voltage and the reference voltage is greater than the fifth cell voltage threshold and less than the fourth cell voltage threshold, set the second preset time as the target balancing time.

[0204] The fifth cell voltage threshold may be set to 15 mV, and the second preset time may be set to 10 hours.

[0205] Based on the static nonlinear region balancing mode, the main control module performs a threshold comparison on the difference between the single cell voltage and the reference voltage. If the difference between the single cell voltage and the reference voltage is greater than the fifth single cell voltage threshold and less than the fourth single cell voltage threshold, the second preset time is set as the target balancing time, thereby realizing dynamic calculation of the balancing time in the static nonlinear region balancing mode, avoiding insufficient or excessive balancing that may result from traditional fixed time length or simple threshold judgment, and minimizing unnecessary energy loss.

[0206] In one example, the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information includes: generating a balancing start instruction according to the target balancing control mode, the balancing flag information, and the target balancing time.

[0207] Based on the triggered static nonlinear region balancing mode, the master control module generates a balancing start instruction according to the target balancing time obtained by processing in step S710 or step S720, and then according to the corresponding balancing mark information, the target balancing time and the static nonlinear region balancing mode, and sends the balancing start instruction to the corresponding slave control module. The slave control module performs the balancing action of the corresponding target balancing time according to the received balancing start instruction, and completes the balancing adjustment of the battery system in the static nonlinear region balancing mode, so as to achieve precise balancing adjustment of the corresponding single cells of the battery system, effectively improve the consistency of the single cells in the battery system, and allow the entire battery system to be charged with more electricity, thereby improving the overall available capacity and energy utilization efficiency of the battery system, extending the overall life of the battery system, and reducing the replacement frequency of the battery system and related maintenance costs.

[0208] In one embodiment, the step of obtaining the operating status information of the battery system and the first characteristic data of each single battery in the battery system includes:

[0209] Second characteristic data of each single battery in the battery system is obtained.

[0210] The second characteristic data may be temperature data of the battery system, total battery voltage or single cell voltage, etc.

[0211] For example, upon system power-up and initialization, the sensor module continuously monitors the cell voltage, total battery voltage, and temperature of each cell. The main control module automatically addresses the cell and verifies the difference between the accumulated sum of the cell voltages and the total battery voltage. The main control module then obtains the second characteristic data.

[0212] In one example, the step of obtaining the operating status information of the battery system and the first characteristic data of each single battery in the battery system includes:

[0213] When each second characteristic data satisfies a preset balanced start condition, the working state information and each first characteristic data are acquired.

[0214] The preset equalization start-up conditions can be obtained through system presets.

[0215] For example, the main control module can periodically detect whether the balancing start-up conditions are met. By processing each second characteristic data, when each second characteristic data meets the preset balancing start-up conditions, it is determined that the battery system meets the balancing start-up conditions, and then the working status information of the battery system and the first characteristic data of each single cell in the battery system are obtained.

[0216] In one embodiment, Figure 8 As shown, each second characteristic data satisfies the preset equalization start condition, including:

[0217] Step S810: Obtain fault detection information of the battery system, temperature data, total battery voltage, and cell voltage of each cell.

[0218] The fault detection information includes single cell voltage detection fault information, temperature detection fault information, current detection fault information, communication fault information, memory fault information, etc. The temperature data may include single cell temperature and balancing board temperature.

[0219] Step S820: When the fault detection information indicates non-fault information, the temperature data is less than a first preset temperature threshold, the lowest cell voltage among the cell voltages is less than a first balancing voltage threshold, and the difference between the sum of the cell voltages and the total battery voltage is less than a first preset voltage threshold, determine that the second characteristic data meets the preset balancing start condition.

[0220] Among them, the first preset temperature threshold may include a battery temperature threshold and a balancing board temperature threshold. The battery temperature threshold can be set to 45°C, and the balancing board temperature threshold can be set to 100°C; the first balancing voltage threshold can be set to 31.V, and the first preset voltage threshold can be set to 10V.

[0221] For example, if the battery management system has no fault related to prohibiting balancing, the fault detection information is determined to be non-fault information.

[0222] It should be noted that balancing is prohibited or stopped if any of the following conditions is not met: the fault detection information is non-fault information, the temperature data is less than a first preset temperature threshold, the lowest cell voltage among the cell voltages is less than a first balancing voltage threshold, or the difference between the sum of the cell voltages and the total battery voltage is less than a first preset voltage threshold.

[0223] In the above example, by judging the balancing start conditions of the battery system, balancing control is started only when the conditions are met, thereby improving the safety and reliability of system balancing.

[0224] In one embodiment, the battery passive balancing control method further includes the steps of:

[0225] When the fault detection information is fault information, the temperature data is greater than or equal to the first preset temperature threshold, the lowest cell voltage among the single cell voltages is less than the second balancing voltage threshold, or the difference between the sum of the single cell voltages and the total battery voltage is greater than the second preset voltage threshold, a balancing interruption instruction is transmitted to the slave control module; the balancing interruption instruction is used to instruct the slave control module to stop performing balancing operations on the corresponding single cell.

[0226] The fault repair information is determined to be fault information when at least one of the following faults prohibiting balancing occurs in the battery management system: cell voltage detection fault, temperature detection fault, current detection fault, communication fault, or memory fault. Temperature data may include cell temperature and balancing board temperature. The first preset temperature threshold includes a cell temperature threshold (e.g., 45°C) and a balancing board temperature threshold (e.g., 100°C). The second balancing voltage threshold may be set to 3.08V; the second preset voltage threshold may be set to 20V. The sum of the cell voltages refers to the sum of the cell voltages obtained after the system automatically addresses the cells.

[0227] The master control module transmits a balancing interrupt instruction to the slave control module when the fault detection information is fault information, the temperature data is greater than or equal to the first preset temperature threshold, the lowest cell voltage among the cell voltages is less than the second balancing voltage threshold, or the difference between the sum of the cell voltages after automatic addressing and the total battery voltage is greater than the second preset voltage threshold. The slave control module then stops performing the balancing operation on the corresponding cell according to the balancing interrupt instruction, thereby stopping the balancing operation of all cell cells when any of the above conditions is detected.

[0228] It should be noted that the balancing process ends when all cells marked for balancing have completed balancing. If a communication failure (such as a CAN communication failure) occurs in the slave control module and it cannot receive instructions from the master control module, the slave control module should actively shut down all balancing channels it controls to ensure the safety of the battery system.

[0229] In one example, during the balancing process, the master control module continuously monitors the remaining balancing time of each battery to be balanced. When the balancing time is reached, the master control module sends a stop instruction to the corresponding slave control module and clears the balancing flag of the corresponding single battery.

[0230] When the balancing task is completed or forced to stop, the main control module updates the working status information, first characteristic data, balancing mark information and target balancing control mode stored in the memory, and the system returns to the normal monitoring state.

[0231] In one embodiment, Figure 9 As shown, the step of transmitting the balancing start instruction to the slave control module includes:

[0232] Step S910: Acquire the temperature of the balancing plate of the battery system.

[0233] For example, during the balancing process, the main control module continuously monitors the maximum temperature of the balancing board, and then obtains the balancing board temperature of the battery system.

[0234] Step S920: When the temperature of the balancing plate is greater than or equal to the second preset temperature threshold, polling and transmitting a balancing start instruction based on the first preset time length and a balancing stop instruction based on the second preset time length to the slave control module until the next obtained balancing plate temperature is less than the third preset temperature threshold.

[0235] Among them, the second preset temperature threshold can be set to 80°C, and the third preset temperature threshold can be set to 70°C; the first preset time length and the second preset time length can be set to 30 seconds respectively.

[0236] The master control module compares the threshold value of the balancing board temperature. When the balancing board temperature is greater than or equal to the second preset temperature threshold, it enters the current reduction mode and polls the slave control module to transmit the balancing start instruction based on the first preset time length and the balancing stop instruction based on the second preset time length. The corresponding slave control module cyclically starts and stops balancing according to the balancing start instruction and the balancing stop instruction until the next obtained balancing board temperature is less than the third preset temperature threshold, so that the equivalent balancing current is reduced to control heat generation.

[0237] Step S930: When the temperature of the balancing plate is lower than a third preset temperature threshold, a balancing start instruction is transmitted to the slave control module.

[0238] When the temperature of the balancing board is lower than the third preset temperature threshold, the master control module determines that the battery temperature has entered the preset range, and transmits a balancing start instruction to the slave control module to restore the normal balancing current. The corresponding slave control module performs balancing operations on the corresponding single battery according to the balancing start instruction.

[0239] In the above embodiment, a thermal management mechanism for balanced current reduction during the balancing process is introduced to effectively prevent overheating of the balancing resistors and related circuits due to long-term high-current operation, thereby ensuring the safety of the battery system and helping to extend the service life of the balancing board. By maintaining the high consistency of each single cell in the battery system over a long period of time, the overall performance degradation of the battery system caused by the short board effect of the single cell is mitigated, thereby effectively extending the actual service life of the battery system.

[0240] It should be understood that although Figures 2 to 9 The 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 9At 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.

[0241] In one embodiment, a battery passive balancing control device is provided, comprising:

[0242] The data acquisition unit is used to acquire the working status information of the battery system and the first characteristic data of each single battery in the battery system.

[0243] The mode screening unit is used to screen multiple preset balancing control modes according to the working state information and each first characteristic data to obtain a target balancing control mode.

[0244] The balancing marking unit is configured to mark the corresponding single battery based on the target balancing control mode when the first characteristic data of the single battery meets the preset balancing marking condition, so as to obtain balancing marking information.

[0245] The instruction transmission unit is used to generate a balancing start instruction according to the target balancing control mode and the balancing mark information, and transmit the balancing start instruction to the slave control module; the balancing start instruction is used to instruct the slave control module to perform a balancing action on the corresponding single battery.

[0246] For the specific definition of the battery passive balancing control device, please refer to the definition of the battery passive balancing control method above and will not be repeated here. Each module in the above-mentioned battery passive balancing control device can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the battery passive balancing control system in hardware form, or can be stored in the memory of the battery passive balancing control system in software form, so that the processor can call and execute the corresponding operations of each of the above modules.

[0247] In one embodiment, Figure 1 As shown, a battery passive balancing control system is also provided, including a master control module 100, multiple slave control modules 200 and a battery system 300, the battery system 300 including multiple single cells 302, the master control module 100 is connected to each slave control module 200 respectively, and the slave control module 200 is connected to at least one single cell 302; the master control module 100 is used to execute the steps of any one of the above-mentioned battery passive balancing control methods.

[0248] The detailed description of the master control module 100, slave control module 200, and battery system 300 is provided in the above embodiments and will not be repeated here. It should be noted that the battery passive balancing control system can be integrated into a battery management system (BMS) or can be independent of the battery management system.

[0249] Based on the master control module 100 being connected to each slave control module 200, the master control module 100 obtains the operating status information of the battery system 300 and the first characteristic data of each single battery 302 in the battery system 300; based on the operating status information and each first characteristic data, multiple preset balancing control modes are screened to obtain a target balancing control mode; based on the target balancing control mode, when the first characteristic data of a single battery 302 meets a preset balancing marking condition, the corresponding single battery 302 is marked to obtain balancing marking information; based on the target balancing control mode and the balancing marking information, a balancing start instruction is generated and transmitted to the corresponding slave control module 200; the slave control module 200 performs a balancing action on the corresponding single battery 302 according to the balancing start instruction, thereby realizing multi-mode balancing control.

[0250] In the above embodiment, the main control module 100 selects the optimal preset balancing control mode as the target balancing control mode based on the working status information and the first characteristic data of each single cell 302, and determines the balancing mark information based on the target balancing control mode, and then performs balancing control on the corresponding single cell 302 based on the target balancing control mode and the balancing mark information, thereby improving the accuracy of the balancing control, diversifying the balancing control strategy, avoiding over-balancing or under-balancing, effectively improving the consistency of the single cells 302 in the battery system 300, extending the cycle life of the battery system 300, reducing the replacement frequency of the battery pack and the related maintenance costs, and improving the balancing efficiency of the battery system 300.

[0251] In one embodiment, 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 passive balancing control methods when the computer program is executed by a processor.

[0252] For example, when a computer program is executed by a processor, it performs the following steps:

[0253] Obtaining operating status information of the battery system and first characteristic data of each single cell in the battery system; screening multiple preset balancing control modes based on the operating status information and each first characteristic data to obtain a target balancing control mode; based on the target balancing control mode, marking the corresponding single cell when the first characteristic data of the single cell meets a preset balancing marking condition to obtain balancing marking information; generating a balancing start instruction based on the target balancing control mode and the balancing marking information, and transmitting the balancing start instruction to the slave control module; the balancing start instruction is used to instruct the slave control module to perform a balancing action on the corresponding single cell.

[0254] 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).

[0255] 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.

[0256] 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 passive balancing control method, characterized in that: The following steps are involved: Acquiring operating status information of a battery system and first characteristic data of each single battery in the battery system; screening a plurality of preset balancing control modes according to the working state information and each of the first characteristic data to obtain a target balancing control mode; Based on the target balancing control mode, when the first characteristic data of the single battery meets the preset balancing marking condition, marking the corresponding single battery to obtain balancing marking information; A balancing start instruction is generated according to the target balancing control mode and the balancing mark information, and the balancing start instruction is transmitted to the slave control module; the balancing start instruction is used to instruct the slave control module to perform a balancing action on the corresponding single battery.

2. The battery passive balancing control method according to claim 1, characterized in that: The step of screening a plurality of preset balancing control modes according to the working state information and each of the first characteristic data to obtain a target balancing control mode includes: screening the preset balancing control modes according to the working state information and the first characteristic data to obtain at least two preset balancing control modes; The priorities of the at least two preset balancing control modes are obtained, and based on the order of priority from high to low, the preset balancing control mode with the highest priority currently and in which balancing is not performed is determined as the target balancing control mode.

3. The battery passive balancing control method according to claim 1, characterized in that: The preset balancing control mode includes a charging end balancing mode; the working state information includes charging end state information; the first characteristic data includes a single cell voltage of a corresponding single cell; The step of screening a plurality of preset balancing control modes according to the working state information and each of the first characteristic data to obtain a target balancing control mode includes: When the working state information is the charging end state information, at least one cell voltage is greater than a first cell voltage threshold, and at least one cell voltage is less than a second cell voltage threshold, the charging end balancing mode is determined as the target balancing control mode.

4. The battery passive balancing control method according to claim 3, characterized in that: The step of marking the corresponding single battery to obtain the balancing marking information when the first characteristic data of the single battery meets the preset balancing marking condition includes: When the cell voltage is greater than a first cell voltage threshold, marking the corresponding cell to obtain the balancing marking information; Before the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information, the step includes: According to the single cell voltage of each single cell, the average battery voltage is obtained; When the battery average voltage is less than a first average voltage threshold, obtaining a first actual capacity of the marked single battery, and obtaining a target balancing time according to a first constant, a preset balancing current, and the first actual capacity; When the battery average voltage is greater than or equal to a first average voltage threshold, obtaining a second actual capacity of the marked single battery, and obtaining a target balancing time according to a second constant, a preset balancing current, and the second actual capacity; The step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information includes: A balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the target balancing time.

5. The battery passive balancing control method according to claim 4, characterized in that: When the first characteristic data of the single battery cell meets the preset balancing marking condition, the step of marking the corresponding single battery cell to obtain balancing marking information further includes: According to the single cell voltage of each single cell, the minimum battery voltage is obtained; When the lowest battery voltage is less than the second average voltage threshold, marking the single battery cells whose corresponding single battery voltages are greater than the first average voltage threshold to obtain the balancing mark information; Before the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information, the step further includes: When the lowest battery voltage is less than a second average voltage threshold and greater than or equal to a third average voltage threshold, obtaining a third actual capacity of the marked single battery, and obtaining the target balancing time according to a third constant, a preset balancing current, and the third actual capacity; When the lowest battery voltage is less than a third average voltage threshold, a fourth actual capacity of the marked single battery is obtained, and the target balancing time is obtained according to a fourth constant, a preset balancing current, and the fourth actual capacity.

6. The battery passive balancing control method according to claim 1, characterized in that: The preset balancing control mode includes a charging end-stage balancing mode; the working state information includes charging end-stage state information; the first characteristic data includes a single cell voltage of a corresponding single cell; The step of screening a plurality of preset balancing control modes according to the working state information and each of the first characteristic data to obtain a target balancing control mode includes: Obtaining a charging current of the battery system; According to the single cell voltage of each single cell, the maximum battery voltage is obtained; When the working status information is the charging end state information, the highest battery voltage is greater than the third single cell voltage threshold, the charging current is less than the first current threshold, and the duration of the charging current reaches a preset time length, the charging end balancing mode is determined as the target balancing control mode.

7. The battery passive balancing control method according to claim 6, characterized in that: The step of marking the corresponding single battery to obtain the balancing marking information when the first characteristic data of the single battery meets the preset balancing marking condition includes: According to the single cell voltage of each single cell, the average battery voltage and the minimum battery voltage are obtained; Obtaining a comparison voltage according to a preset voltage constant, the average battery voltage, and the lowest battery voltage; When the cell voltage is greater than the comparison voltage, marking the corresponding cell to obtain the balancing marking information; The step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information includes: Set the preset initial time as the target balancing time; A balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the target balancing time.

8. The battery passive balancing control method according to claim 1, characterized in that: The preset balancing control mode includes a static linear region balancing mode; the working state information includes charging static state information; the first characteristic data includes a single cell voltage of a corresponding single cell; The step of screening a plurality of preset balancing control modes according to the working state information and each of the first characteristic data to obtain a target balancing control mode includes: When the working state information is the charging static state information and the cell voltage of each of the single cells is in a linear variation range of a preset OCV-SOC curve, the static linear region balancing mode is determined as the target balancing control mode.

9. The battery passive balancing control method according to claim 8, characterized in that: The step of marking the corresponding single battery to obtain the balancing marking information when the first characteristic data of the single battery meets the preset balancing marking condition includes: Obtaining a baseline remaining capacity of the battery system; When the cell voltage meets the preset voltage condition, obtaining the actual battery capacity of the corresponding cell, and obtaining the comparative capacity according to the actual battery capacity and the reference remaining capacity; When the remaining capacity of the corresponding single battery is greater than the comparison capacity, marking the corresponding single battery to obtain the balancing mark information; Before the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information, the step includes: Obtaining a discharge capacity according to the reference remaining capacity and the remaining capacity of the corresponding single battery; Obtaining a target balancing time according to the to-be-discharged capacity and the preset balancing current; The step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information includes: generating a balancing start instruction according to the target balancing control mode, the balancing mark information, and the target balancing time; Alternatively, a balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the ready-to-discharge capacity.

10. The battery passive balancing control method according to claim 1, characterized in that: The preset balancing control mode includes a static nonlinear region balancing mode; the working state information includes charging static state information; the first characteristic data includes a single cell voltage of a corresponding single cell; The step of screening a plurality of preset balancing control modes according to the working state information and each of the first characteristic data to obtain a target balancing control mode includes: When the working state information is the charging static state information and the cell voltage of each of the single cells is in a nonlinear variation range of a preset OCV-SOC curve, the static nonlinear region balancing mode is determined as the target balancing control mode.

11. The battery passive balancing control method according to claim 10, characterized in that: The step of marking the corresponding single battery to obtain the balancing marking information when the first characteristic data of the single battery meets the preset balancing marking condition includes: Obtaining a reference voltage of the battery system; When the difference between the single cell voltage and the reference voltage meets a preset threshold condition, marking the corresponding single cell to obtain the balancing mark information; Before the step of generating a balancing start instruction according to the target balancing control mode and the balancing flag information, the step includes: When the difference between the cell voltage and the reference voltage is greater than a fourth cell voltage threshold, setting the first preset time as the target balancing time; When the difference between the cell voltage and the reference voltage is greater than a fifth cell voltage threshold and less than a fourth cell voltage threshold, setting the second preset time as the target balancing time; The step of generating a balancing start instruction according to the target balancing control mode and the balancing mark information includes: A balancing start instruction is generated according to the target balancing control mode, the balancing mark information and the target balancing time.

12. The battery passive balancing control method according to any one of claims 1 to 11, characterized in that: The step of obtaining the working status information of the battery system and the first characteristic data of each single battery in the battery system includes: Acquire second characteristic data of each single battery in the battery system; The step of obtaining the working status information of the battery system and the first characteristic data of each single battery in the battery system includes: When each of the second characteristic data satisfies a preset balanced start condition, the working state information and each of the first characteristic data are acquired.

13. The battery passive balancing control method according to claim 12, characterized in that: Each of the second characteristic data satisfies a preset balancing start condition, including: Obtain battery system fault detection information, temperature data, total battery voltage and single cell voltage of each single cell; When the fault detection information is non-fault information, the temperature data is less than a first preset temperature threshold, the lowest cell voltage among the single cell voltages is less than a first balancing voltage threshold, and the difference between the sum of the single cell voltages and the total battery voltage is less than a first preset voltage threshold, it is determined that each of the second characteristic data meets a preset balancing start condition.

14. The battery passive balancing control method according to claim 13, characterized in that: Also includes the steps: Transmitting a balancing interrupt instruction to a slave control module when the fault detection information is fault information, the temperature data is greater than or equal to a first preset temperature threshold, the lowest cell voltage among the cell voltages is less than a second balancing voltage threshold, or the difference between the sum of the cell voltages and the total battery voltage is greater than a second preset voltage threshold; The balancing interruption instruction is used to instruct the slave control module to stop performing a balancing operation on the corresponding single battery.

15. The battery passive balancing control method according to claim 13, wherein: The step of transmitting the balancing start instruction to the slave control module includes: Get the temperature of the balancing plate of the battery system; When the temperature of the balancing plate is greater than or equal to the second preset temperature threshold, polling and transmitting a balancing start instruction based on the first preset time length and a balancing stop instruction based on the second preset time length to the slave control module until the next obtained balancing plate temperature is less than the third preset temperature threshold; When the temperature of the balancing plate is lower than a third preset temperature threshold, the balancing start instruction is transmitted to the slave control module.

16. A battery passive balancing control system, characterized in that: It includes a master control module, multiple slave control modules and a battery system, wherein the battery system includes multiple single cells, the master control module is connected to each of the slave control modules respectively, and the slave control module is connected to at least one of the single cells; The main control module is used to execute the steps of the battery passive balancing control method according to any one of claims 1 to 15.

17. 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 passive balancing control method according to any one of claims 1 to 15 are implemented.

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