Battery management method, device and system, storage medium and program product

Abstract

The embodiment of the invention provides a battery management method, device and system, a storage medium and a program product. The method comprises the following steps: firstly, determining a dynamic power state of each battery cell under a current working condition based on battery cell voltage, current and temperature data collected by a battery monitoring unit in real time; and then the power state is used as an equalization criterion, target battery cells with the highest power state and the lowest power state in the system are identified, and when the difference between the power states exceeds a preset threshold value, the equalization circuit is controlled to directly transfer the electric energy from the high-power state battery cell to the low-power state battery cell. According to the scheme, the equalization basis is replaced with the real-time dynamic power state from the traditional static voltage or charge state, so that the accurate response to the real charge and discharge capacity difference of the battery cells is realized, and the capacity equalization among the battery cells is actively maintained in the charging and discharging processes; the overall available capacity, the output power and the cycle life of the battery pack are obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery energy storage, and in particular to a battery management method, device, equipment, storage medium and program product. BACKGROUND

[0002] In the field of battery energy storage, the equalization control strategy of the battery management system (BMS) is one of the core technologies, and its advantages and disadvantages are directly related to the overall available capacity, output power performance and system cycle life of the battery pack. The equalization process not only needs to improve the energy utilization rate of the battery pack, but also must take into account the difference in the state of health of each battery cell, to prevent accelerated battery aging or safety risks caused by the short board effect due to overcharging or overdischarging.

[0003] At present, most BMSs use passive or active equalization strategies based on voltage or static state of charge (SoC) criteria. Such equalization strategies are difficult to accurately identify the real capacity difference of the battery cells during charging and discharging, especially when the voltage platform area or the battery cells are not consistent in aging, the equalization effect is significantly reduced, which easily leads to waste of battery pack capacity, limited power and shortened life. SUMMARY

[0004] The embodiments of the present application provide a battery management method, device, system, storage medium and program product, which are used to actively maintain the capacity balance among battery cells during charging and discharging, and improve the overall available capacity, output power and cycle life of the battery pack.

[0005] In a first aspect, the embodiments of the present application provide a battery management method applied to a battery management system, the battery management system comprising a battery monitoring unit, a processor and an equalization circuit, the battery monitoring unit being configured to collect first battery data of a plurality of battery cells in a battery in real time, the equalization circuit being configured to transfer electrical energy in the battery cells, and the processor being configured to execute the battery management method, the method comprising:

[0006] obtaining the first battery data collected by the battery monitoring unit, the first battery data comprising at least one of voltage values, current values and temperature values of the plurality of battery cells respectively;

[0007] determining power states of the plurality of battery cells based on the first battery data;

[0008] determining a first target battery cell and a second target battery cell in the plurality of battery cells based on the power states of the plurality of battery cells, the first target battery cell being a battery cell with the maximum power state value in the plurality of battery cells, and the second target battery cell being a battery cell with the minimum power state value in the plurality of battery cells;

[0009] In a case where a difference between the power states of the first target battery cell and the second target battery cell is greater than or equal to a preset value, the equalization circuit is controlled to transfer electric energy of the first target battery cell to the second target battery cell.

[0010] In the embodiments of the present application, by replacing the equalization basis from the traditional static voltage or state of charge to the real-time dynamic power state, the real charging and discharging capacity difference of the battery cells is accurately responded, so that the capacity balance among the battery cells is actively maintained during the charging and discharging process, and the overall available capacity, output power and cycle life of the battery pack are significantly improved.

[0011] In a possible implementation, the power states of the plurality of battery cells are determined based on the first battery data, including:

[0012] The historical cycle data of the plurality of battery cells are obtained, and the historical cycle data include at least one of the cumulative charge amount and the cycle charge number of the plurality of battery cells;

[0013] The historical cycle data and the first battery data are calculated by using a preset filtering algorithm to obtain real-time states of charge (SoC) of the plurality of battery cells, and the preset filtering algorithm includes at least one of an extended Kalman filter (EKF) algorithm and an unscented Kalman filter (UKF) algorithm;

[0014] The historical cycle data are calculated based on a preset attenuation model to obtain real-time states of health (SOH) of the plurality of battery cells;

[0015] The power states of the plurality of battery cells are determined based on the SoC and the SOH of the plurality of battery cells.

[0016] In the embodiments of the present application, by integrating the historical cycle data and the real-time running data of the battery cells, and using advanced estimation algorithms such as the extended Kalman filter and the unscented Kalman filter, the state of charge and the state of health of the battery cells are dynamically estimated with high precision; based on the accurate SoC and SoH, the real-time power states of the battery cells under the current conditions are further determined. By establishing the determination of the power states on the basis of multi-dimensional, dynamic and high-precision state cognition, not only the problems such as the difficulty in balancing in the voltage plateau region and the large influence of aging on the SoC estimation in the traditional method are overcome, but also the equalization control can accurately respond to the real-time capacity difference of the battery cells, so that the capacity utilization rate, the power output stability and the overall life of the battery pack are more significantly improved, and the accurate optimization of the whole chain from "perception" to "decision" is realized.

[0017] In a possible implementation, the battery is in a charging condition, and the power states are charging power states of the plurality of battery cells;

[0018] The power states of the plurality of battery cells are determined based on the SoC and the SOH, including:

[0019] fitting the SoC and the SOH based on the first fitting model to obtain a charging power state of the plurality of battery cells; wherein for any battery cell in the plurality of battery cells, the charging power state of the battery cell is less than or equal to a maximum charging power of the battery cell.

[0020] In the embodiments of the present application, the high-precision dynamically estimated state of charge and state of health of the battery cell are mapped to the maximum charging power state that the battery cell can safely receive under the current condition through the preset first fitting model. This method deeply integrates the charging safety boundary and the real-time state of the battery cell, not only ensures the accuracy and timeliness of the power supplement in the balancing process, but also eliminates the overcharging risk caused by the balancing operation from the root. This enables the battery pack to intelligently identify and actively compensate for the insufficient charging capacity of the "short board battery cell" during the fast charging process, thereby effectively improving the overall charging efficiency, balancing speed, and system safety, and prolonging the service life of the battery pack in the fast charging scenario.

[0021] In a possible implementation, the battery is in a discharging working condition, and the power state is a discharging power state of the plurality of battery cells.

[0022] Based on the SoC and the SOH, the power state of the plurality of battery cells is determined, including:

[0023] fitting the SoC and the SOH based on the second fitting model to obtain a discharging power state of the plurality of battery cells; wherein for any battery cell in the plurality of battery cells, the discharging power state of the battery cell is less than or equal to a maximum discharging power of the battery cell.

[0024] In the embodiments of the present application, the high-precision estimated state of charge and state of health of the battery cell are mapped to the maximum discharging power state that the battery cell can safely release under the current condition through the preset second fitting model. This method accurately associates the discharging safety limit with the real-time state of the battery cell, not only ensures the rationality and efficiency of the power extraction in the balancing process, but also effectively prevents the over-discharging risk caused by the balancing operation by constraining the discharging power state not to exceed the maximum discharging power of the battery cell. This enables the battery pack to actively identify and schedule the energy support of the "advantageous battery cell" to the "short board battery cell" during the high-load or continuous discharging process, thereby significantly improving the overall discharging power stability, prolonging the single endurance mileage, and enhancing the reliability and durability of the battery pack under dynamic load.

[0025] In a possible implementation, based on the power state of the plurality of battery cells, a first target battery cell and a second target battery cell in the plurality of battery cells are determined, including:

[0026] Based on the power state of the plurality of battery cells, the power states of the plurality of battery cells are sorted;

[0027] determining, from the plurality of battery cells, a first target battery cell having a maximum power state, and determining, from the plurality of battery cells, a second target battery cell having a minimum power state.

[0028] In the embodiments of the present application, the battery cell with the highest power state is efficiently and clearly identified as the energy transfer supplier (the first target battery cell) and the battery cell with the lowest power state is efficiently and clearly identified as the energy transfer receiver (the second target battery cell) by dynamically sorting the real-time power states of all battery cells. The implementation method is logically clear and computationally efficient, and can capture the maximum capacity difference between battery cells in the battery pack in real time, providing accurate target pointing for balancing actions. This method avoids the decision delay or misjudgment caused by ambiguous thresholds or multiple target conflicts in traditional strategies, ensuring that the balancing system can quickly respond to the battery cells that most need adjustment, thereby significantly improving the timeliness and overall control efficiency of the balancing response.

[0029] In a possible implementation,

[0030] In the case where the number of battery cells with the maximum power state is greater than 1, the first target battery cell is determined to be the battery cell with the minimum SoC among the plurality of battery cells with the maximum power state.

[0031] In the case where the number of battery cells with the minimum power state is greater than 1, the second target battery cell is determined to be the battery cell with the maximum SoC among the plurality of battery cells with the minimum power state.

[0032] In the embodiments of the present application, the state of charge is further introduced as a secondary arbitration criterion for the case where the power states of multiple battery cells are equal. This implementation clearly stipulates that, when the power states of multiple battery cells are equal, the battery cell with the lowest state of charge is selected as the energy transfer supplier, and when the power states of multiple battery cells are equal, the battery cell with the highest state of charge is selected as the energy transfer receiver. This method not only solves the problem of uniqueness in decision-making when the states of multiple battery cells are equal, but also achieves more intelligent balancing scheduling by introducing the state of charge: during discharging, the battery cell with low power but high power capacity is preferentially protected, and during charging, the battery cell with high power but low power capacity is preferentially supplemented. Thus, while accurately balancing the power state, the energy distribution and aging process among battery cells are further optimized, improving the precision of the balancing strategy and the consistency of long-term use of the battery pack.

[0033] In a possible implementation, the balancing circuit includes a switch matrix and a current converter.

[0034] The control of the balancing circuit to transfer the electrical energy of the first target battery cell to the second target battery cell includes:

[0035] Based on the types of the first target battery cell and the second target battery cell, a target working mode of the balancing circuit is determined.

[0036] The control equalization circuit transfers the electric energy of the first target electric core to the second target electric core based on the target working mode, based on the switch matrix and the current converter.

[0037] In the embodiments of the present application, the equalization circuit composed of the switch matrix and the current converter dynamically determines the corresponding working mode based on the types of the first target electric core and the second target electric core, and realizes flexible, efficient and safe electric energy transfer. The energy transfer path and the circuit working mode are adaptively matched in this implementation, such as step-up or step-down conversion between the electric core and the module, thereby supporting various energy scheduling scenarios such as electric core to electric core, electric core to module, module to electric core, etc. This method not only significantly improves the application range and topology flexibility of the equalization system, but also guarantees the efficiency and reliability of the energy transfer process through precise hardware control, while achieving the dynamic equalization goal, minimizing energy loss and circuit complexity, and improving the overall energy efficiency and engineering practicability of the system.

[0038] In a possible implementation, the target working mode of the equalization circuit is determined based on the types of the first target electric core and the second target electric core, comprising:

[0039] The type of the first target electric core is a single electric core, the type of the second target electric core is a single electric core or an electric core module, and the target working mode is a CTP mode of electric core-battery pack.

[0040] The type of the first target electric core is an electric core module, the type of the second target electric core is a single electric core or an electric core module, and the target working mode is a PTC mode of battery pack-electric core.

[0041] In the embodiments of the present application, the working mode of the equalization circuit is divided into electric core-battery pack mode and battery pack-electric core mode according to whether the first target electric core and the second target electric core are single electric cores or electric core modules. This implementation realizes flexible energy scheduling from the electric core level to the system level through type judgment, in which the CTP mode is used to release excess energy of the single electric core to the module, and the PTC mode is used to distribute the concentrated energy of the module to the single electric core. This patterned energy flow design not only greatly improves the adaptability and scalability of the equalization system in different application scenarios, but also more efficiently utilizes the available energy in the system for state optimization, thereby realizing more intelligent and economic dynamic equalization management in the whole life cycle of the battery pack.

[0042] In a possible implementation, the control equalization circuit transfers the electric energy of the first target electric core to the second target electric core based on the target working mode, based on the switch matrix and the current converter, comprising:

[0043] In a case where the target working mode is the CTP mode, the switch matrix is controlled to be turned on at the input end of the current converter and the first target battery cell, and at the output end of the current converter and the second target battery cell; the current converter is controlled to start the boost working mode, and the electric energy of the first target battery cell is transferred to the second target battery cell.

[0044] In a case where the target working mode is the PTC mode, the switch matrix is controlled to be turned on at the input end of the current converter and the first target battery cell, and at the output end of the current converter and the second target battery cell; the current converter is controlled to start the boost working mode, and the electric energy of the first target battery cell is transferred to the second target battery cell.

[0045] In the embodiments of the present application, the conduction logic of the switch matrix and the working mode of the current converter are defined for the CTP and PTC working modes. In the CTP mode, the system connects the first target battery cell to the input end of the current converter, connects the second target battery cell to the output end, and starts the boost mode, so as to realize the energy "upload" of the single battery cell to the module; in the PTC mode, the first target battery cell is connected to the input end, the second target battery cell is connected to the output end, and the buck mode is started, so as to complete the energy "downloading" of the module to the single battery cell. The implementation method matches the standard switch control and the circuit mode, so that the balancing process has a clear, reliable and efficient physical execution path, which not only reduces the control complexity and the circuit design risk, but also ensures the safety and energy efficiency of the energy transfer process, and provides a solid hardware operation guarantee for the stable, fast and accurate dynamic balancing of the battery management system under various actual working conditions.

[0046] In a possible implementation, the method further includes:

[0047] In a case where the duration of the first target battery cell and the second target battery cell in the target state is greater than or equal to the preset duration, the balancing circuit is controlled to stop transferring the electric energy of the first target battery cell to the second target battery cell; wherein the target state includes: the difference between the power states of the first target battery cell and the second target battery cell is less than a preset value.

[0048] In this embodiment, a time- and state-based equalization stop mechanism is introduced. After the power state difference between the first and second target cells remains below a preset threshold for a certain duration, the system automatically controls the equalization circuit to stop energy transfer. This design not only effectively avoids false triggering and frequent start-stops caused by instantaneous fluctuations or measurement noise, but also ensures a stable equalization effect through delayed judgment, preventing "over-equalization" or "under-equalization." Simultaneously, this mechanism helps reduce system standby power consumption and unnecessary switching losses in circuit components. While ensuring equalization accuracy, it further improves the overall system energy efficiency and operational reliability, extends the service life of the equalization circuit, and achieves intelligent, lightweight, and highly efficient equalization process management.

[0049] In one possible implementation, before acquiring the first battery data collected by the battery monitoring unit, the method further includes:

[0050] Initialize the battery management system;

[0051] Check if the battery monitoring unit is functioning properly;

[0052] When the battery monitoring unit is functioning normally, second battery data of multiple cells is collected. The second battery data includes at least one of the voltage and temperature values ​​of the multiple cells.

[0053] When the second battery data of multiple battery cells meets the preset requirements, the first battery data collected by the battery monitoring unit is acquired.

[0054] Alternatively, the battery protection program may be triggered if the battery monitoring unit malfunctions or if the second battery data of at least one of the multiple battery cells does not meet the preset requirements.

[0055] In this embodiment, a multi-layered interlocked safety startup process is constructed by adding system initialization, monitoring unit self-test, and cell safety status pre-test steps before equalization control. This implementation requires that after the system is powered on, the functional integrity of the battery monitoring unit is first verified, and then key static parameters such as voltage and temperature of each cell are collected and compared with preset safety ranges. Only when all hardware states are normal and all cells are within the safety window will the system enter the real-time data acquisition and dynamic equalization process; otherwise, the battery protection program will be directly triggered, interrupting subsequent operations. This method establishes active equalization control on a highly reliable safety verification basis, effectively preventing the chain risks that may be caused by erroneous equalization actions triggered when monitoring fails or when cells are already in dangerous states such as overvoltage, undervoltage, or overtemperature. It significantly improves the functional safety level and robustness of the battery management system, providing a prerequisite guarantee for achieving safe equalization under all operating conditions.

[0056] In a second aspect, the embodiments of the present application provide a battery management device applied to a battery management system, the battery management system comprising a battery monitoring unit and an equalization circuit, the battery monitoring unit being configured to collect first battery data of a plurality of battery cells in real time, and the equalization circuit being configured to transfer electric energy in the battery cells, and the battery management device comprising:

[0057] an acquisition module configured to acquire the first battery data collected by the battery monitoring unit, the first battery data comprising at least one of voltage, current and temperature of each of the plurality of battery cells;

[0058] a determination module configured to determine power states of the plurality of battery cells based on the first battery data, and determine a first target battery cell and a second target battery cell in the plurality of battery cells based on the power states of the plurality of battery cells, the first target battery cell being a battery cell with the maximum power state value in the plurality of battery cells, and the second target battery cell being a battery cell with the minimum power state value in the plurality of battery cells;

[0059] a control module configured to control the equalization circuit to transfer electric energy of the first target battery cell to the second target battery cell when a difference between the power states of the first target battery cell and the second target battery cell is greater than or equal to a preset value.

[0060] In a possible implementation, the determination module is specifically configured to:

[0061] acquire historical cycle data of the plurality of battery cells, the historical cycle data comprising at least one of cumulative charging quantity and cycle charging times of the plurality of battery cells;

[0062] perform calculation on the historical cycle data and the first battery data by using a preset filtering algorithm to obtain real-time state of charge (SoC) of the plurality of battery cells, the preset filtering algorithm comprising at least one of extended Kalman filter (EKF) algorithm and unscented Kalman filter (UKF) algorithm;

[0063] perform calculation on the historical cycle data based on a preset attenuation model to obtain real-time state of health (SOH) of the plurality of battery cells;

[0064] determine the power states of the plurality of battery cells based on the SoC and the SOH of the plurality of battery cells.

[0065] In a possible implementation, the battery is in a charging condition, and the power states are charging power states of the plurality of battery cells.

[0066] The determination module is specifically configured to perform fitting on the SoC and the SOH based on a first fitting model to obtain the charging power states of the plurality of battery cells, and for any battery cell in the plurality of battery cells, the charging power state of the battery cell is less than or equal to the maximum charging power of the battery cell.

[0067] In a possible implementation, the battery is in a discharging condition, and the power states are discharging power states of the plurality of battery cells.

[0068] The determining module is specifically configured to: fit the SoC and the SOH based on the second fitting model to obtain a plurality of power states of the plurality of battery cells; and for any battery cell in the plurality of battery cells, the power state of the battery cell is less than or equal to the maximum discharge power of the battery cell.

[0069] In a possible implementation, the determining module is specifically configured to:

[0070] sort the power states of the plurality of battery cells based on the power states of the plurality of battery cells;

[0071] determine that a battery cell with the maximum power state in the plurality of battery cells is a first target battery cell, and determine that a battery cell with the minimum power state in the plurality of battery cells is a second target battery cell.

[0072] In a possible implementation, when the number of battery cells with the maximum power state is greater than 1, the first target battery cell is determined to be a battery cell with the minimum SoC in the plurality of battery cells with the maximum power state;

[0073] when the number of battery cells with the minimum power state is greater than 1, the second target battery cell is determined to be a battery cell with the maximum SoC in the plurality of battery cells with the minimum power state.

[0074] In a possible implementation, the balancing circuit includes a switch matrix and a current converter.

[0075] The determining module is further configured to: determine a target working mode of the balancing circuit based on the types of the first target battery cell and the second target battery cell.

[0076] The control module is specifically configured to: control the balancing circuit to transfer the electric energy of the first target battery cell to the second target battery cell based on the target working mode, the switch matrix, and the current converter.

[0077] In a possible implementation, the control module is specifically configured to:

[0078] when the type of the first target battery cell is a single battery cell, and the type of the second target battery cell is a single battery cell or a battery cell module, the target working mode is determined to be a battery cell-battery pack CTP mode;

[0079] when the type of the first target battery cell is a battery cell module, and the type of the second target battery cell is a single battery cell or a battery cell module, the target working mode is determined to be a battery pack-battery cell PTC mode.

[0080] In a possible implementation, the control module is specifically configured to:

[0081] In a case where the target working mode is the CTP mode, the switch matrix is controlled to be turned on at the input end of the first target battery cell and the current converter, and turned on at the output end of the second target battery cell and the current converter; the current converter is controlled to start the boost working mode, and the electric energy of the first target battery cell is transferred to the second target battery cell.

[0082] In a case where the target working mode is the PTC mode, the switch matrix is controlled to be turned on at the input end of the first target battery cell and the current converter, and turned on at the output end of the second target battery cell and the current converter; the current converter is controlled to start the boost working mode, and the electric energy of the first target battery cell is transferred to the second target battery cell.

[0083] In a possible implementation, the control module is further configured to:

[0084] In a case where the duration of the target state of the first target battery cell and the second target battery cell is greater than or equal to the preset duration, the equalization circuit is controlled to stop transferring the electric energy of the first target battery cell to the second target battery cell; wherein the target state includes that the difference between the power states of the first target battery cell and the second target battery cell is less than the preset value.

[0085] In a possible implementation, the control module is further configured to:

[0086] initialize the battery management system;

[0087] detect whether the battery monitoring unit is normal;

[0088] In a case where the battery monitoring unit is normal, collect second battery data of the plurality of battery cells, the second battery data including at least one of voltage values and temperature values of the plurality of battery cells;

[0089] In a case where the second battery data of the plurality of battery cells meets the preset requirement, obtain the first battery data collected by the battery monitoring unit;

[0090] Or, in a case where the battery monitoring unit is abnormal, or the second battery data of at least one of the plurality of battery cells does not meet the preset requirement, trigger the battery protection program.

[0091] In a third aspect, the embodiments of the present application provide a BMS system, including: a battery monitoring unit, an equalization circuit, a memory and a processor, the battery monitoring unit is configured to collect first battery data of a plurality of battery cells in a battery in real time, and the equalization circuit is configured to transfer electric energy in the battery cells;

[0092] The memory stores computer execution instructions;

[0093] The processor executes the computer execution instructions stored in the memory, so that the processor executes the first aspect and / or various possible implementations of the first aspect.

[0094] In a fourth aspect, the embodiments of the present application provide a vehicle, comprising a battery including a plurality of battery cells, and a BMS system as in the third aspect.

[0095] In a fifth aspect, the embodiments of the present application provide a computer readable storage medium, which stores computer execution instructions, and the computer execution instructions are executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0096] In a sixth aspect, the embodiments of the present application provide a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0097] The battery management method, device, system, storage medium and program product provided by the embodiments of the present application. In the method, first, based on the battery monitoring unit real-time acquisition of cell voltage, current and temperature data, the dynamic power state of each battery cell under the current working condition is determined; then, taking the power state as the equalization criterion, the target battery cell with the highest and lowest power state in the system is identified, and when the power state difference exceeds the preset threshold, the equalization circuit is controlled to directly transfer the electric energy from the high power state battery cell to the low power state battery cell. The scheme replaces the traditional static voltage or state of charge as the equalization basis with the real-time dynamic power state, realizes the accurate response to the real charge and discharge capacity difference of the battery cell, and actively maintains the capacity balance among the battery cells during the charging and discharging process, significantly improves the overall available capacity, output power and cycle life of the battery pack, and achieves the systematic optimization goal. BRIEF DESCRIPTION OF DRAWINGS

[0098] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0099] Figure 1 The scene schematic diagram of the battery management method provided by the present application;

[0100] Figure 2 The flowchart of the battery management method provided by the present application Figure 1 ;

[0101] Figure 3 The flowchart of the battery management method provided by the present application Figure 2 ;

[0102] Figure 4 The architecture schematic of the BMS system provided by the present application Figure 1 ;

[0103] Figure 5 The flowchart of the battery management method provided by the present applicationFigure 3 ;

[0104] Figure 6 Structure diagram of battery management device provided by the present application;

[0105] Figure 7 Structure diagram of BMS system provided by the present application Figure 2 ;

[0106] Figure 8 Structure diagram of vehicle provided by the present application.

[0107] The specific embodiments of the present application have been shown by the above-mentioned drawings, and will be described in more detail hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0108] The exemplary embodiments will be described in detail herein with reference to the accompanying drawings. In the following description, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments are not representative of all embodiments consistent with the present application. Rather, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0109] First, the terms involved in the present application are explained:

[0110] Battery Management System (BMS)

[0111] State of Power (SoP), the maximum energy that a battery or a cell can safely receive or release per unit time under current conditions, with the unit being watt.

[0112] Charging State of Power (CSoP), the maximum charging power that a cell can safely receive per unit time under the current state of health, temperature, and remaining capacity, with the unit being watt.

[0113] Discharging State of Power (DSoP), the maximum discharging power that a cell can safely release per unit time under the current state of health, temperature, and remaining capacity, with the unit being watt.

[0114] State of Charge (SoC), the percentage of the current available capacity of the battery to its maximum available capacity at the current state of health, reflecting how much power is left.

[0115] State of Health (SoH), the percentage of the current maximum available capacity (or performance) of the battery to its rated capacity (or performance) at the factory, reflecting how much the battery has degraded.

[0116] Analog-to-Digital Converter (ADC), an electronic component that converts continuous analog signals (such as voltage, current) into discrete digital signals for processors to read and process.

[0117] Negative Temperature Coefficient Thermistor (NTC temperature sensor), a semiconductor device whose resistance decreases exponentially with temperature, commonly used for precise temperature measurement.

[0118] Extended Kalman Filter (EKF), an algorithm that linearizes a nonlinear system locally through first-order Taylor expansion, and then applies standard Kalman filtering for state estimation, suitable for moderately nonlinear systems.

[0119] Unscented Kalman Filter (UKF), a filtering algorithm that selects sample points through unscented transformation to directly approximate the probability distribution of the state of a nonlinear system, without the need for linearization, with higher accuracy in strongly nonlinear systems.

[0120] Electrically Erasable Programmable Read-Only Memory (EEPROM), a non-volatile memory that can be written and erased multiple times online, with data not lost after power off, commonly used for storing device configuration parameters and historical data.

[0121] Open Circuit Voltage-State of Charge Calibration Curve (OCV-SoC calibration curve), a curve established through experiments that corresponds one-to-one between the open circuit voltage of the battery and its state of charge at different temperatures, used for initial calibration of SoC.

[0122] Controller Area Network Bus (CAN bus), a high-reliability, distributed real-time control support serial communication network protocol, widely used in automotive electronics and industrial control field for module data exchange.

[0123] Cell to Pack Mode (CTP mode), in active balancing, energy transfer mode from single cell to the entire battery pack or parallel module.

[0124] Pack to Cell Mode (PTC mode), in active balancing, energy transfer mode from the entire battery pack or parallel module to a single cell.

[0125] General Purpose Input / Output (GPIO), microcontroller or integrated circuit pins that can be flexibly configured by the user through software as digital input or output functions.

[0126] Pulse Width Modulation (PWM), a technique that uses the proportion of time a digital signal is high (duty cycle) in a cycle to equivalent analog or control power devices.

[0127] Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), a semiconductor power switch device that uses electric field effect to control current, with fast switching speed, small on-resistance, and simple drive characteristics, commonly used in switch matrix and power conversion.

[0128] Direct Current-Direct Current Converter (DC-DC converter), a power electronic device that converts one DC voltage level to another, achieving high-efficiency power conversion through high-frequency switching and energy storage elements.

[0129] Depth of Discharge (DoD), the percentage of the total capacity of the battery released during discharge, is an important parameter to measure the degree of battery use and affect its life.

[0130] With the popularity of electric vehicles, lithium-ion batteries have become the mainstream choice due to their high energy density (e.g., ternary lithium-ion batteries can have an energy density of 200-300 Wh / kg, and lithium iron phosphate batteries can have an energy density of 150-200 Wh / kg), long service life (e.g., a typical cycle life is 1000-3000 times, and some high-end products can have a cycle life of more than 5000 times), and fast charging and discharging capability (e.g., supporting 1C-5C charging, and some models are adapted to 8C or more super-fast charging).

[0131] However, a battery module is composed of a large number of series and parallel cells (e.g., a passenger car battery pack usually contains hundreds to thousands of cells, such as the common 96-string and 108-string structures), and there are differences in capacity, internal resistance, and aging between different cells. For example, the initial capacity difference of new cells is usually 2%-5%, and the difference after aging can be expanded to more than 10%; the internal resistance difference of new cells is about 5%-8%, and the internal resistance difference after 1000 cycles can be more than 20%; the aging rate difference of cells in the same battery pack can be 15%-20% / year.

[0132] As can be seen, the above differences can limit the overall performance of the battery pack to the worst cell, for example, when the capacity of a cell is only 80% of other cells, the full charge and discharge capacity of the battery pack will be limited to the capacity level of that cell, resulting in a large amount of capacity waste.

[0133] In related technologies, excess energy is dissipated by power resistors to achieve power balancing. The circuit structure required by this scheme includes resistors, switches, and control chips, which has a low cost. However, the energy loss rate of this method is as high as 50%-80%, and the balancing speed is slow (e.g., the single-cell balancing current is usually 100-500 mA, and it takes 4-20 hours to fully charge a 2000 mAh cell), which is only suitable for small-capacity and low-balancing-demand scenarios.

[0134] Therefore, the embodiments of the present application provide a battery management method, device, system, storage medium, and program product. First, based on the cell voltage, current, and temperature data collected by the battery monitoring unit in real time, the dynamic power state of each cell under the current working condition is determined; then, taking the power state as the balancing criterion, the target cells with the highest and lowest power states in the system are identified, and when the power state difference exceeds the preset threshold, the balancing circuit is controlled to directly transfer the power from the high-power state cell to the low-power state cell. This scheme replaces the traditional static voltage or state of charge as the balancing basis with the real-time dynamic power state, accurately responds to the real charging and discharging capacity difference of the cells, and actively maintains the capacity balance between the cells during charging and discharging, thereby significantly improving the overall available capacity, output power, and cycle life of the battery pack, and achieving the goal of systematic optimization.

[0135] Figure 1 The scene diagram of the battery management method provided by the present application is shown in FIG. 1. As shown in FIG. 1, the battery management system is composed of a battery pack, a battery management unit, and a battery monitoring unit.Figure 1 As shown, the specific application scenario of the present application includes a battery and a BMS system. The battery includes a plurality of battery cells, and the BMS system includes a battery monitoring unit and an equalization circuit. The battery monitoring unit is configured to collect battery data of the plurality of battery cells in real time, and the equalization circuit is configured to transfer electrical energy in the battery cells.

[0136] In some embodiments, the BMS system further includes a processor configured to execute the battery management method of the embodiments of the present application.

[0137] In some embodiments, the processor is configured to control the battery monitoring unit to collect the battery data, determine the power state of the plurality of battery cells based on the battery data, and control the equalization circuit to perform the electrical energy equalization processing based on the power state.

[0138] In some embodiments, the processor includes a state estimation module and an equalization control module. The state estimation module is configured to receive the battery data collected by the battery monitoring unit and determine the power state of the plurality of battery cells based on the battery data. The equalization control module is configured to control the equalization circuit to perform the electrical energy equalization processing based on the power state of the plurality of battery cells.

[0139] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described in detail in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0140] Figure 2 Flowchart of the battery management method provided by the present application Figure 1 The execution subject of the embodiments of the present application is the above-mentioned BMS system (or the processor in the BMS system). As shown, the method includes the following steps: Figure 2

[0141] S201, obtaining first battery data collected by a battery monitoring unit.

[0142] The first battery data includes at least one of the voltage value, the current value and the temperature value of each of the plurality of battery cells.

[0143] In some embodiments, the battery monitoring unit can obtain data in the following scenarios:

[0144] 1. Fixed period data acquisition, for example, the processor of the battery management system requests complete battery pack data from the battery monitoring unit once at a certain period (for example, 10 milliseconds), and correspondingly, the battery monitoring unit triggers the ADC channel inside the battery monitoring unit to start working after receiving the request of the processor, so as to collect the voltage, temperature and total current of the plurality of battery cells. ​

[0145] 2. Event-triggered, for example, when the system detects a sudden change in operating condition (such as a charging pile starting, sudden acceleration, braking energy recovery), the processor will immediately interrupt the current task and trigger the battery monitoring unit to collect data.

[0146] Specifically, the processor can communicate with the battery monitoring unit through the high-speed SPI bus in the "command-response" mode, which includes the following steps:

[0147] 1. The processor of the battery management system sends a unified sampling instruction to the battery monitoring unit. This instruction will synchronously trigger all ADC channels in the monitoring unit to start working at the same time, ensuring that the voltage, temperature, and total current of all cells are measured at the same instant.

[0148] 2. In a very short time (usually tens of microseconds), all analog quantities are digitized.

[0149] 3. The processor reads a structured data packet from the monitoring unit in sequence, which usually contains the following contents:

[0150] All cell voltage values (for example, 96 strings of cells correspond to 96 voltage data); multiple key point temperature values; battery pack total current value; status flag and check code (used to determine whether the data is valid).

[0151] In some optional embodiments, the processor can also check the data after receiving the raw data. Specifically, the following checking methods are included but not limited to:

[0152] 1. Reasonableness check, i.e. checking whether each voltage value is within the physically possible range (such as between 2.5V and 4.35V).

[0153] 2. Consistency check, i.e. comparing the voltage difference between adjacent cells with the historical trend. If the data of a cell suddenly changes while the surrounding cells are normal, the data is marked as suspicious.

[0154] 3. Integrity check, i.e. checking the check code in the data packet to confirm that no bit error has occurred during transmission.

[0155] In some embodiments, the battery monitoring unit can use a dedicated battery monitoring chip, combined with high-precision voltage sampling circuit, Hall current sensor and NTC temperature sensor.

[0156] Among them, the battery monitoring chip (such as TI BQ76952, ADI LTC6813) supports 16-24 battery core monitoring at the same time; the sampling accuracy of the high-precision voltage sampling circuit is ±2mV, and the sampling rate is 100Hz; the measurement range of the Hall current sensor is -500A to +500A, and the accuracy is ±1%; the measurement range of the NTC temperature sensor is -40℃ to 85℃, and the accuracy is ±1℃, 3-5 are arranged for each module, respectively monitoring the surface, tab and internal temperature of the battery core.

[0157] In some embodiments, the battery monitoring unit collects battery voltage, current, temperature data in real time, and the data is uploaded to the processor (such as state estimation module) through the SPI communication protocol (transmission rate 1-10Mbps), while having overvoltage (such as single battery overvoltage threshold 4.35-4.45V, configurable), undervoltage (such as undervoltage threshold 2.5-2.7V, configurable), overcurrent (such as charging overcurrent threshold 1.5-2C, discharging overcurrent threshold 2-3C), overtemperature (such as overtemperature threshold 60-65℃, low temperature protection threshold -20 to -10℃) protection function, when triggering protection, immediately cut off the charging and discharging circuit.

[0158] In the embodiments of the application, through the interaction mechanism combining timing and triggering, command and response, the real-time, synchronization and high reliability of obtaining battery data can be ensured, thereby providing accurate and consistent data for all subsequent advanced algorithms (SoC estimation, SoP calculation), thereby improving system reliability.

[0159] S202, determining the power state of the plurality of battery cores based on the first battery data.

[0160] In some embodiments, step S202 is performed by a state estimation module in the processor, and the workflow is as follows:

[0161] 1. Data receiving and preparation, that is, real-time acquisition of voltage, current, temperature raw data of all battery cores from the battery monitoring chip (such as BQ76952) through the SPI bus (1-10Mbps).

[0162] In some embodiments, since the battery monitoring chip samples at a rate of 100Hz, the processor (such as the state estimation module) can collect and process a batch of data every 100ms, ensuring that the data is aligned in time.

[0163] 2. State estimation core calculation (executed every 100ms), which specifically includes the following:

[0164] a. SoC estimation:

[0165] Algorithm selection: automatically select EKF (normal temperature, small current) or UKF (low temperature, large current) algorithm according to current working conditions (temperature, current size).

[0166] Calculation process: read the historical cycle data of the battery cell stored in the EEPROM (used to correct the actual capacity C n ) at the same time, and continuously correct the SoC estimation result combined with the real-time voltage measurement value, so that the error is finally controlled to be less than or equal to 3%.

[0167] Initial calibration: if the system is powered on and stationary for more than 30 minutes, directly query the OCV-SoC calibration curve (select the corresponding curve according to the current temperature) to obtain a high-precision initial SoC.

[0168] b. SoH estimation, that is, analyzing long-term data (such as cumulative charge and discharge capacity) read from the EEPROM, calculating the actual capacity attenuation degree of the current battery cell through the capacity attenuation model, obtaining SoH, and the error is less than or equal to 4%.

[0169] c. CSoP / DSoP calculation, that is, substituting the calculated SoC, SoH and real-time temperature into the pre-calibrated polynomial model.

[0170] Among them, when the battery is charging, the CSoP of the battery is calculated using the following formula:

[0171]

[0172] Among them, the coefficients a, b, c, d, and e are calibrated for a specific battery cell model through a large number of experiments. For example, for a certain ternary lithium battery cell at 25°C and SoH of 100%, a set of calibration coefficients may be .

[0173] When the battery is discharging, the DSoP of the battery is calculated using the following formula:

[0174]

[0175] Among them, the coefficients f, g, h, i, and j are also calibrated through experiments, and their rules are similar to CSoP but the values are different, which are not limited in the embodiments of the present application.

[0176] In some embodiments, the above calculation results are compared with the absolute maximum safe power of the battery cell (for example, 10W charging and 15W discharging), and the smaller value is taken as the final output to ensure safety. Among them, the estimation error is less than or equal to 5%.

[0177] In some embodiments, the state estimation module sends the SoC, CSoP / DSoP, SoH and other data of each battery cell to the equalization control module through the CAN bus (250-500kbps).

[0178] In the embodiments of the application, through a special algorithm module, high-precision data and high-performance filtering algorithms are used to realize accurate calculation of key states (SoC, SoH) in the battery that cannot be directly measured, and further mapping to CSoP / DSoP that can be directly used for control decision, so that the subsequent balancing provides a decision basis with high accuracy, high reliability and safety boundary.

[0179] S203, determining a first target cell and a second target cell in the plurality of cells based on the power states of the plurality of cells.

[0180] Among them, the first target cell is the cell with the maximum power state value in the plurality of cells, and the second target cell is the cell with the minimum power state value in the plurality of cells.

[0181] In some embodiments, step S203 is performed by a balancing control module in the processor, and the workflow is as follows:

[0182] 1. Data receiving and working condition judgment; that is, the balancing control module receives the state data packet of all cells through the CAN bus, and judges whether the current battery is in charging or discharging working condition (for example, by judging the direction of the total current).

[0183] 2. Sorting and screening; when charging, the CSoP values of all cells are sorted in descending order, and the maximum value CSoP max and the minimum value CSoP min are found, and the corresponding cell numbers Cell max and Cell min are recorded. When discharging, DSoP is sorted, and DSoP max , DSoP min and the corresponding cells are found.

[0184] 3. If multiple cells have CSoP (or DSoP) values that are equal to the maximum or minimum, the following method is used for judgment:

[0185] When charging (selecting target cell Cell min ): among the cells with the minimum CSoP, the cell with the lowest SoC is selected. Because the cell with the lowest SoC is the most "starving", the effect of supplementing energy is the most significant, and the whole package charging capacity can be effectively improved.

[0186] When discharging (selecting source cell Cell max ), among the cells with the maximum DSoP, the cell with the highest SoC is selected. Because the cell with the highest SoC has the most sufficient energy, it is the most sustainable and has the lowest risk as an energy source.

[0187] In the embodiments of the present disclosure, the "most critical short board" (the second target battery cell) and the "most suitable supply source" (the first target battery cell) affecting the overall performance of the system can be quickly and clearly located with extremely low computing overhead (sorting operation). Meanwhile, the introduced arbitration mechanism avoids the algorithm from being in a dilemma of choice, optimizes the influence of the balancing behavior on the long-term consistency of the battery, and makes the balancing strategy more intelligent and long-term.

[0188] S204, in the case that the difference between the power states of the first target battery cell and the second target battery cell is greater than or equal to a preset value, controlling the balancing circuit to transfer the electric energy of the first target battery cell to the second target battery cell.

[0189] In some embodiments, step S204 is a cooperative control process of the balancing control module and the balancing circuit, and the workflow is as follows:

[0190] 1. Threshold comparison and trigger decision; that is, the balancing control module calculates the power difference value: Or .

[0191] Further, ΔP is compared with a preset value (10 W charging and 15 W discharging); if ΔP is greater than or equal to the preset value: it is determined that balancing is needed, and the next step is performed; if ΔP is less than the preset value: the next control period is waited.

[0192] 2. Work mode determination and instruction issuing; first, according to whether Cell max and Cell min are single battery cells or a whole module, the work mode of the balancing circuit is determined:

[0193] CTP mode: energy is transferred from a single battery cell to a single battery cell or a module.

[0194] PTC mode: energy is transferred from a module to a single battery cell.

[0195] Further, the balancing control module sends instructions to the balancing circuit through a control line (such as GPIO, PWM, or special digital communication), including: mode, source address, target address, and initial transfer current.

[0196] 3. Closed-loop execution of energy transfer; that is, the balancing circuit accurately turns on the corresponding MOSFET in the switch matrix according to the instructions to build a physical path from the source to the target. Meanwhile, in the CTP mode, if the voltage of Cell max is lower than the voltage of Cell min , the DC-DC works in boost mode; otherwise, the DC-DC works in buck mode; in the PTC mode, it is usually to supply power from a high-voltage module to a low-voltage single battery cell, and the DC-DC works in buck mode.

[0197] 4、Dynamic adjustment and monitoring, i.e. the equalization control module recalculates ΔP every 10 ms, and dynamically adjusts the transfer current according to the latest ΔP (for example, 1-3 A when ΔP is 10-20 W, and 3-5 A when ΔP is less than 20 W).

[0198] 5、Real-time safety monitoring, i.e. the equalization control module ensures that the voltage of any battery cell does not exceed the limit during the transfer process (such as discharging no less than 2.7 V, and charging no higher than 4.35 V), and the current does not exceed the maximum capacity of the DC-DC (5 A).

[0199] 6、Equalization stop and hibernation, i.e. when the equalization control module monitors that ΔP is less than the threshold for 5 seconds, it is determined that the equalization target has been reached; the equalization control module sends a stop instruction to the equalization circuit, controls the DC-DC of the equalization control module to be closed, and the switch matrix to turn off all MOSFETs.

[0200] In some embodiments, the current equalization log can also be stored in the EEPROM, and then the control module enters a low-power hibernation state (current less than 10 mA) and waits for the next wake-up.

[0201] In the embodiments of the present application, the perfect landing from "intelligent decision-making" to "safe execution" is achieved. The adaptive threshold and dynamic current adjustment ensure the accuracy and efficiency of the equalization action; the multiple real-time monitoring ensures the absolute safety of the process; and the automatic stop and hibernation mechanism greatly reduces the standby power consumption of the system.

[0202] Figure 3 Flowchart of the battery management method provided in the present application Figure 2 The execution subject of the embodiments of the present application is the above-mentioned BMS system (or the processor in the BMS system). As shown in the figure, the method comprises the following steps: Figure 3

[0203] S301, initializing the battery management system.

[0204] In some embodiments, after the system is powered on, the equalization control module can start to execute the startup code to initialize the battery management system.

[0205] Specifically, it includes but is not limited to at least one of the following:

[0206] 1、Initialize internal clock, memory, and interrupt controller.

[0207] 2、Initialize all peripheral interfaces: SPI (for connecting battery monitoring unit), CAN (for external communication), GPIO (for controlling switch matrix and DC-DC), and ADC (may be used for additional monitoring).

[0208] ​3. Read system configuration parameters from EEPROM, such as protection threshold, equalization threshold, cell calibration parameters, etc.

[0209] S302, detect whether the battery monitoring unit is normal.

[0210] Specifically, the equalization control module sends a self-test instruction to the battery monitoring chip (such as BQ76952) through the SPI bus; correspondingly, the battery monitoring module performs internal diagnosis to check whether the ADC reference voltage is stable, whether the logic circuit and communication interface are normal; at the same time, the equalization control module checks whether the output of the Hall current sensor is within a reasonable range near zero current, and whether the temperature sensor circuit is open or short. Among them, the self-test process needs to be completed within less than or equal to 100 ms.

[0211] In some embodiments, if the battery monitoring unit is normal, S303 is performed; if the battery monitoring unit is not normal, jump to S305 to trigger protection. For example, record the fault code "self-test failure", and alarm through the CAN bus, etc.

[0212] S303, in the case where the battery monitoring unit is normal, collect second battery data of a plurality of battery cells.

[0213] Among them, the second battery data includes at least one of the voltage value and the temperature value of the plurality of battery cells.

[0214] S304, in the case where the second battery data of the plurality of battery cells meets the preset requirement, acquire first battery data collected by the battery monitoring unit.

[0215] For example, determine whether the voltage (V cell ) of all battery cells meets: (safety voltage range at room temperature, lower limit adjusted to 2.5V at low temperature-20℃, upper limit adjusted to 4.25V at high temperature 60℃);

[0216] And determine whether the temperature (T cell ) meets .

[0217] In some embodiments, if the voltage and the temperature are both within the corresponding range, it is determined that the second battery data meets the preset requirement; if at least one of the voltage and the temperature is not within the above range, it is determined that the second battery data does not meet the preset requirement.

[0218] It should be noted that the way to acquire the first battery data collected by the battery monitoring unit is similar to the embodiment shown in Figure 2 , which will not be repeated here.

[0219] S305: If the battery monitoring unit malfunctions or the second battery data of at least one of the multiple battery cells does not meet the preset requirements, the battery protection program is triggered.

[0220] S306. Based on the first battery data, determine the power state of multiple cells.

[0221] S307. Based on the power state of multiple cells, determine the first target cell and the second target cell among the multiple cells.

[0222] In some embodiments, the first target cell is the cell with the largest power state value among a plurality of cells, and the second target cell is the cell with the smallest power state value among a plurality of cells.

[0223] S308. If the power state difference between the first target cell and the second target cell is greater than or equal to a preset value, the control equalization circuit transfers the electrical energy of the first target cell to the second target cell.

[0224] It should be noted that steps S306-S307 are related to... Figure 2 Steps S202-S204 in the illustrated embodiment are similar and will not be described in detail here.

[0225] Figure 4 Schematic diagram of the BMS system provided in this application Figure 1 .like Figure 4 As shown, the BMS system includes:

[0226] Battery monitoring unit: Located on the left side of the BMS system, it is used to collect voltage, current and temperature data of each cell;

[0227] State estimation module: Located in the middle of the BMS system, it is used to receive data from the battery monitoring unit and estimate the SoC and SoH;

[0228] Equalization control module: Located on the right side of the system, connected to the state estimation module, responsible for judging the CSoP / DSoP difference and issuing energy transfer commands;

[0229] Equalization circuit: Located below the system, it consists of a current converter (such as a DC-DC converter) and a switching matrix. It receives instructions from the equalization control module to realize energy transfer between battery cells.

[0230] The following is combined with Figure 5 The battery management method of the BMS system is explained:

[0231] Figure 5 Flowchart of the battery management method provided in this application Figure 3 The execution entity of this application embodiment is the aforementioned BMS system (or the processor in the BMS system). For example... Figure 5As shown, the method includes the following steps S501-S508, wherein S501-S505 can be performed by the state estimation module, and S506-S508 can be performed by the balancing control module. Specifically:

[0232] S501, acquire first battery data collected by the battery monitoring unit.

[0233] The first battery data includes at least one of voltage, current and temperature of each battery cell.

[0234] It should be noted that step S501 is similar to step S201 in the embodiment shown, and will not be repeated here. Figure 2 The step S201 in the embodiment shown is similar to step S201 in the embodiment shown, and will not be repeated here.

[0235] S502, acquire historical cycle data of the plurality of battery cells.

[0236] The historical cycle data includes at least one of cumulative charge and cycle charge number of the plurality of battery cells.

[0237] In some embodiments, the state estimation module can read the historical cycle data of each battery cell from the non-volatile memory (EEPROM) of the BMS system, including cumulative charge, cycle charge number, etc.

[0238] S503, calculate the historical cycle data and the first battery data using a preset filtering algorithm to obtain real-time state of charge SoC of the plurality of battery cells.

[0239] The preset filtering algorithm includes at least one of extended Kalman filter EKF algorithm and unscented Kalman filter UKF.

[0240] Specifically, the implementation process of step S503 is as follows:

[0241] 1, data input preparation:

[0242] Real-time data (first battery data): receive voltage (V), current (I) and temperature (T) from the battery monitoring module, and the sampling period is usually 100ms.

[0243] Historical cycle data: read the historical cycle data of the battery cell from the EEPROM, which is used to correct the capacity model.

[0244] Calibration data: load the OCV-SoC-T curve family (open circuit voltage- state of charge correspondence under different temperatures) calibrated in advance through experiments.

[0245] 2, SoC initial value calibration (cold start or after long static):

[0246] Specifically, when the system has been idle for more than 30 minutes, the cell voltage is considered to have stabilized to an open-circuit state. Further, the current open-circuit voltage and temperature (T) of the cell are measured. Based on the current temperature T, the corresponding OCV-SoC calibration curve is selected, and the initial SoC value is determined from the measured OCV value through table lookup or interpolation. The error in this process is controlled to be less than or equal to 2%. This provides a high-precision starting point for subsequent real-time integration.

[0247] 3. Real-time dynamic estimation of SoC (during system runtime):

[0248] The ampere-hour integration method is used to calculate the change in SoC based on the real-time current, starting from the initial SoC. Specifically, the change in SoC, SoC(t), is calculated using the following formula:

[0249]

[0250] Wherein, SoC(t) is the state of charge (percentage or decimal) at time t; SoC(t0) is the state of charge at the initial time t0 (obtained through calibration such as the open-circuit voltage method); The time integral of current I from time t0 to time t represents the total amount of charge flowing into or out of the battery. The sign of current I is negative during charging and positive during discharging.

[0251] It should be noted that, It is not the fixed rated capacity of the battery, but the current actual maximum usable capacity of the cell after dynamic correction by the capacity estimation model (see S504).

[0252] 4. Correction using EKF / UKF filtering:

[0253] Specifically, the algorithm first uses the SoC prediction obtained from ampere-hour integration, real-time measured terminal voltage V, real-time current I, real-time temperature T, and the battery's equivalent circuit model parameters (which are affected by SoC, temperature, and aging). Then, based on the optimal SoC estimate from the previous moment and the current current, the algorithm predicts the current SoC and terminal voltage. Next, the predicted terminal voltage is compared with the measured terminal voltage, and the error is calculated. Finally, using the Kalman gain (a dynamically calculated weighting coefficient), the voltage measurement error is used to optimally correct the predicted SoC value.

[0254] In some embodiments, under normal operating conditions (e.g., ambient temperature of 25°C and current less than or equal to 1C), an EKF (Extended Kalman Filter) is used. Under extreme operating conditions (e.g., low temperature less than or equal to 0°C and high current greater than or equal to 2C), a UKF (Unscented Kalman Filter) is used.

[0255] In this embodiment, the triple guarantee of "open-circuit voltage method initial calibration", "ampere-hour integration method real-time tracking" and "Kalman filter method dynamic correction" enables high-precision and high-robust estimation of SoC under all operating conditions and throughout its entire life cycle, providing the most crucial dynamic input for subsequent power state calculation.

[0256] S504. Based on the preset attenuation model, the historical cycle data is calculated to obtain the real-time health status (SOH) of multiple cells.

[0257] The specific implementation process of step S504 is as follows:

[0258] 1. Continuously read and update the historical cycle data of the battery cell from the EEPROM. Key parameters include, but are not limited to, at least one of the following: cumulative charge / discharge capacity (total ampere-hour throughput); number of cycles; historical temperature distribution records (especially the cumulative time of high-temperature exposure); average depth of charge / discharge (DoD), etc.

[0259] 2. Input the aforementioned historical data into the preset empirical model for battery cell capacity degradation. This empirical model is a mathematical relationship (or a set of formulas / tables) obtained by fitting a large amount of aging experimental data from similar battery cells. It describes the quantitative relationship between capacity degradation and factors such as cycle count, cumulative throughput, operating temperature, and depth of charge / discharge. For example, the model might show that: for every 10°C increase in temperature, the aging rate doubles; deep cycling (100% DoD) causes greater capacity damage than shallow cycling (20% DoD).

[0260] 3. Output Results. Among them, the current actual maximum usable capacity is the model output of the actual maximum capacity of the cell under the current aging state (unit: Ah).

[0261] 4. Calculate SoH using the following formula:

[0262]

[0263] in, This refers to the factory rated capacity of the battery cell.

[0264] S505, based on the SoC and SOH of multiple battery cells, determines the power state of multiple battery cells.

[0265] In some embodiments, the battery is in a charging state, and the power state is the charging power state of multiple cells. The SoC and SOH are fitted based on a first fitting model to obtain the charging power state of multiple cells. Specifically, for any one of the multiple cells, the charging power state of the cell is less than or equal to the cell's maximum charging power.

[0266] In some embodiments, the battery is in a discharge state, and the power state is the discharge power state of multiple cells. The SoC and SOH are fitted based on a second fitting model to obtain the discharge power state of the multiple cells. Specifically, for any one of the multiple cells, the discharge power state of the cell is less than or equal to the cell's maximum discharge power.

[0267] The specific implementation process of step S505 is as follows:

[0268] 1. Input preparation, namely, obtaining the real-time SoC from S503, the SoH from S504, and the current temperature T.

[0269] 2. Model calculation. This includes the following scenarios:

[0270] Scenario 1 (charging condition): The first fitting model (polynomial) is used to calculate the state of power (CSoP). The calculation method for CSoP is as follows: Figure 3 The illustrated embodiment;

[0271] Scenario 2 (discharge condition): The second fitting model is used to calculate the discharge power state (DSoP). The calculation method for DSoP is as follows: Figure 3 The illustrated embodiment.

[0272] In this embodiment, the actual safety capability boundary of the cell under the current charge, temperature and health status can be reflected in real time, and it serves as the only and most effective criterion for subsequent equalization judgment (S506-S508), so that the equalization action is directly committed to improving the overall power capability of the battery pack, fundamentally solving the problem of voltage plateau area equalization and the problem of differentiated management of aging cells.

[0273] S506. Based on the power state of multiple cells, determine the first target cell and the second target cell among the multiple cells.

[0274] In some embodiments, step S506 specifically includes the following steps:

[0275] 1. Sort the power states of multiple battery cells based on their power states;

[0276] 2. Determine the cell with the highest power state among multiple cells as the first target cell, and determine the cell with the lowest power state among multiple cells as the second target cell.

[0277] Specifically, the equalization control module (such as an STM32F507 MCU) receives the SoC, CSoP, and DSoP data packets for each battery cell from the state estimation module via the CAN bus. Based on the total current direction or external commands, it determines whether the battery is currently charging or discharging. If charging, it sorts the charging power states of all cells to obtain a CSoP list from highest to lowest. If discharging, it sorts the discharging power states of all cells to obtain a DSoP list from highest to lowest.

[0278] The first target cell (energy donor) is the cell with the highest state-of-power (SOP) value in the sorted list. During charging, i.e., CSoP... max The corresponding battery cell exhibits the strongest charging acceptance under current conditions and is least likely to become a charging bottleneck. Therefore, it is suitable as an energy "output" cell, transferring some of its energy to help the weaker battery cell. During discharge, the primary target battery cell (energy donor) is the DSoP. max The corresponding battery cell has the strongest discharge output capability under the current conditions and the most remaining energy that can be released, so it is suitable as an "energy source" to support other battery cells.

[0279] The second target cell (energy acceptor) is the cell with the lowest state of power (SOP) value in the sorted list. During charging, i.e., CSoP... min The corresponding battery cell is currently the weakest link in terms of charging capability, and is most likely to be fully charged prematurely, thus limiting the overall charging capacity of the battery pack. Therefore, it is the "highest priority target" for energy replenishment. During discharge, i.e., DSoP... min The corresponding battery cell is the weakest link in terms of discharge capacity. It is most likely to run out of power prematurely, thus limiting the overall output of the battery pack. Therefore, it needs to obtain energy support from other battery cells.

[0280] At this point, the initial objective based on the primary criterion (state of power) has been determined. However, in actual battery packs, multiple cells may have the same state of power, necessitating the introduction of a secondary arbitration mechanism. Specific scenarios include the following:

[0281] Scenario 1: When the number of cells with the highest power status is greater than 1, the first target cell is determined to be the cell with the smallest SoC among the multiple cells with the highest power status.

[0282] In this scenario, under discharge conditions, multiple battery cells have the same and maximum DSoP value. The first target cell is then determined to be the one with the highest SoC among these parallel cells. This embodiment, by selecting the cell with the highest SoC from multiple equally capable "power sources" as the donor, maximizes the sustainability and safety of the energy transfer process. Because high-SoC cells have more energy reserves, the risk of their voltage dropping to the cutoff voltage when drawing power from them is lower, preventing the cell from failing before it can support others.

[0283] Scenario 2: When the number of cells with the lowest power state is greater than 1, the second target cell is determined to be the cell with the largest SoC among the multiple cells with the lowest power state.

[0284] In this scenario, under charging conditions, multiple battery cells have the same and minimum CSoP values ​​(all are considered "weakest links"). The second target cell is then determined to be the one with the lowest CSoP among these parallel cells. This embodiment maximizes the marginal benefit of this balancing process in increasing the overall usable capacity of the battery pack by selecting the cell with the lowest CSoP from among multiple equally capable "weakest links." This is because replenishing the most "starved" cell most effectively delays its reaching the full charge cutoff voltage, thus providing more charging time for other cells and ultimately increasing the total charge received by the entire battery pack.

[0285] S507. If the power state difference between the first target cell and the second target cell is greater than or equal to a preset value, the control equalization circuit transfers the electrical energy of the first target cell to the second target cell.

[0286] In some embodiments, the equalization circuit includes a switching matrix and a current converter.

[0287] In some embodiments, the system performs a validity check before executing any transfer. Specifically, the difference ΔP is calculated based on the following formula:

[0288]

[0289] Furthermore, determine whether ΔP is greater than or equal to the preset threshold (10W for charging and 15W for discharging by default).

[0290] If ΔP is less than the threshold: determine that the current difference does not require intervention, do not perform the transfer, and return to the monitoring status; if ΔP is greater than or equal to the threshold: confirm that balancing is required, trigger subsequent S5071 and S5072, and start the energy transfer process.

[0291] In some embodiments, step S507 specifically includes S5071-S5072:

[0292] S5071. Based on the types of the first target battery cell and the second target battery cell, determine the target operating mode of the equalization circuit.

[0293] Scenario 1: When the type of the first target cell is a single cell and the type of the second target cell is a single cell or a cell module, the target working mode is determined to be the cell-to-pack (CTP) mode.

[0294] Scenario 2: When the type of the first target cell is a cell module and the type of the second target cell is a single cell or a cell module, the target operating mode is determined to be the battery pack-cell PTC mode.

[0295] In this embodiment, when the bottleneck is a single cell, the PTC mode is used first because the module has a large energy pool and can quickly "compensate" for it; when the donor is a single cell, the CTP mode is used to release its excess energy into the system.

[0296] S5072, the control equalization circuit, based on the target operating mode, transfers the electrical energy of the first target cell to the second target cell based on the switching matrix and current converter.

[0297] Specifically, when the target operating mode is CTP mode, the control switch matrix turns on the input terminal of the first target battery cell and the current converter, and turns on the output terminal of the second target battery cell and the current converter; the control current converter starts the boost operating mode and transfers the electrical energy of the first target battery cell to the second target battery cell.

[0298] Specifically, the execution process in CTP mode (taking a single battery cell as the first target cell as an example):

[0299] The control equalization circuit turns on the MOSFET switch connecting the positive and negative terminals of the first target cell to the input terminal of the DC-DC converter; and turns on the MOSFET switch connecting the output terminal of the DC-DC converter to the second target cell (which may be a single cell or a module bus), thereby constructing a current path of first target cell → DC-DC → second target cell.

[0300] The operating modes of the DC-DC converter include the following:

[0301] Case A (Discharge of the first target cell): This usually occurs when the first target cell is a high SOC cell. The DC-DC converter operates in buck mode to reduce the cell voltage to a level suitable for the receiver.

[0302] Case B (Charging the second target cell): When it is necessary to charge the second target cell that serves as the module, if the voltage of a single cell is lower than the module voltage, the DC-DC converter needs to operate in boost mode.

[0303] Specifically, when the target operating mode is PTC mode, the control switch matrix turns on the input terminal of the first target battery cell and the current converter, and turns on the output terminal of the second target battery cell and the current converter; the control current converter starts the buck operating mode and transfers the electrical energy of the first target battery cell to the second target battery cell.

[0304] Specifically, the execution process under PTC mode (taking a single cell as an example for the second target cell):

[0305] Switch matrix operation: Turn on the MOSFET switch connecting the module (first target cell) bus to the input terminal of the DC-DC converter; turn on the MOSFET switch connecting the output terminal of the DC-DC converter to the second target cell (single cell).

[0306] DC-DC converter operating mode: Because the module voltage is much higher than the voltage of a single cell, the DC-DC converter operates in constant buck mode, safely reducing the high-voltage bus voltage to a voltage suitable for charging a single cell. Correspondingly, electrical energy flows out from the module bus, is stepped down by the DC-DC converter, and then used for cell charging. min Single cell charging.

[0307] In some embodiments, the system performs strict closed-loop control throughout the energy transfer process (whether in CTP or PTC mode):

[0308] For example, the system monitors the voltage of the first target cell in real time (to prevent over-discharge, e.g., not lower than 2.7V) and the voltage of the second target cell (to prevent overcharging, e.g., not higher than 4.35V); simultaneously, it ensures that the transfer current does not exceed the maximum capacity of the DC-DC converter (e.g., 5A) and the cell's safety limit. If any of the above exceeds the limit, the system will immediately interrupt the transfer and enter a protection state.

[0309] Alternatively, the balance control module recalculates the power state difference ΔP between the first and second target cells every 10ms and dynamically adjusts the DC-DC output current based on the latest ΔP. When ΔP is large, a larger current (e.g., 3-5A) is used for rapid balancing; when ΔP decreases, the current is automatically reduced (e.g., 1-3A) for fine adjustment. This scheme achieves smooth balancing with a "fast first, slow later" approach, avoiding "over-balancing" (i.e., the donor being over-discharged or the acceptor being over-charged), and improving balancing accuracy and efficiency.

[0310] In this embodiment, intelligent decision-making based on power state is transformed into a safe, efficient, and precise physical energy transfer operation through "patterned path selection (CTP / PTC)" and "adaptive closed-loop control (monitoring + adjustment)". It is not just a simple "conduction switch", but a precision control process that integrates real-time protection and dynamic optimization, ensuring that the balancing action improves battery pack performance while absolutely guaranteeing its safety and durability.

[0311] S508. If the duration of the first target cell and the second target cell in the target state is greater than or equal to the preset duration, the control equalization circuit stops transferring the electrical energy of the first target cell to the second target cell.

[0312] The target state includes: the difference in power state between the first target cell and the second target cell is less than a preset value.

[0313] In some embodiments, a stop operation is performed if the following conditions one and two are met, wherein:

[0314] Condition 1: The real-time power state difference (ΔP) between the first target cell and the second target cell must be less than the preset trigger threshold.

[0315] Condition one is the fundamental condition for stopping balancing. That is, through the previous energy transfer, the capacity difference between the two target cells has been reduced to an acceptable range. Continuing to balance will not only yield little benefit, but may also introduce new inconsistencies due to over-adjustment.

[0316] Condition 2: The aforementioned state of "ΔP less than the preset value" must be maintained for a period of time, reaching or exceeding a preset duration (e.g., 5 seconds). This prevents misjudgments caused by instantaneous fluctuations or noise. Specifically, battery voltage and current may fluctuate slightly under dynamic operating conditions, potentially causing ΔP to momentarily fall below the threshold. The time requirement necessitates that ΔP remain stably below the threshold, eliminating instantaneous interference and ensuring the robustness and reliability of the stop decision.

[0317] In some embodiments, when the stopping condition is met, the equalization control module executes the following process to ensure safety and data integrity:

[0318] The equalization control module sends a clear "stop transfer" command to the equalization circuit; accordingly, the equalization circuit's DC-DC converter first receives the command, its internal control loop linearly reduces the output current to zero, and then turns off the power switch to stop working.

[0319] Furthermore, after confirming that the DC-DC output is zero, the equalization control module drives the switching matrix to sequentially turn off all the MOSFET switches that were previously turned on for this equalization, completely cutting off the Cell.max With Cell min All electrical connections between them are established through equalization circuits.

[0320] In some embodiments, the system may store the "operation log" of this load balancing operation in a non-volatile memory (such as EEPROM). The log typically includes, but is not limited to, the following:

[0321] The timestamps for the start and end of the equalization process, and the cell numbers of the participating cells. max Cell min The total transferred energy (estimated value), average transferred current, and final ΔP value after this equilibrium are all included.

[0322] In some embodiments, this data is of great value for subsequent analysis of the effectiveness of the balancing strategy, assessment of cell aging trends, and optimization of algorithm parameters.

[0323] In some embodiments, after the system completes the above operations, the equalization control module puts itself and related circuits into a low-power sleep or standby state (e.g., sleep current less than 10mA). At this time, the system still monitors the basic state of the battery (such as voltage and temperature), but stops all high-power calculations and equalization actions, significantly reducing the system's standby power consumption.

[0324] In this embodiment, by monitoring ΔP and automatically stopping, the system ensures that the balancing action is "just right," avoiding the loss of energy from the Cell. max Over-transfer to Cell min This leads to a reversal of the superior and inferior positions of the two, creating a new and reverse imbalance, achieving a precise closed loop, and preventing "over-equilibrium".

[0325] Meanwhile, the introduction of "duration duration" determination effectively filters out interference caused by measurement noise and transient changes in operating conditions, avoids frequent false starts and stops of the equalization system, and improves the overall stability and reliability of operation.

[0326] Furthermore, it provides automatic stop and hibernation mechanisms, ensuring that the balancing circuit only works when necessary and is powered off immediately once the task is completed, minimizing unnecessary energy loss and improving the overall energy efficiency of the BMS.

[0327] Finally, the triggering conditions of S508 and S507 (ΔP is greater than or equal to the threshold) together form a complete automated management closed loop of "trigger → execution → monitoring → stop", making the balancing system an intelligent agent that can autonomously judge, execute, and terminate.

[0328] Figure 6This is a schematic diagram of the battery management device provided in this application. The battery management device is applied to a battery management system, which includes a battery monitoring unit and an balancing circuit. The battery monitoring unit is used to collect first-cell data from multiple battery cells in real time, and the balancing circuit is used to transfer electrical energy from the battery cells. Figure 6 As shown, the battery management device includes:

[0329] The acquisition module 601 is used to acquire first battery data collected by the battery monitoring unit. The first battery data includes at least one of the voltage value, current value and temperature value of each of the multiple battery cells.

[0330] The determination module 602 is used to determine the power state of multiple cells based on the first battery data; and to determine a first target cell and a second target cell among the multiple cells based on the power state of multiple cells, wherein the first target cell is the cell with the largest power state value among the multiple cells, and the second target cell is the cell with the smallest power state value among the multiple cells.

[0331] The control module 603 is used to control the equalization circuit to transfer the electrical energy of the first target cell to the second target cell when the power state difference between the first target cell and the second target cell is greater than or equal to a preset value.

[0332] In one possible implementation, the determining module 602 is specifically used for:

[0333] Obtain historical cycle data for multiple battery cells. The historical cycle data includes at least one of the following: the cumulative charge amount and the number of charge cycles for multiple battery cells.

[0334] A preset filtering algorithm is used to calculate the historical cycle data and the first battery data to obtain the real-time state of charge (SoC) of multiple cells. The preset filtering algorithm includes at least one of the extended Kalman filter (EKF) algorithm and the unscented Kalman filter (UKF) algorithm.

[0335] Based on a preset attenuation model, historical cycle data is calculated to obtain the real-time health status (SOH) of multiple cells.

[0336] Based on the SoC and SOH of multiple battery cells, the power state of multiple battery cells is determined.

[0337] In one possible implementation, the battery is in a charging state, and the power state is the charging power state of multiple cells; the determining module 602 is specifically used for:

[0338] The first fitting model is used to fit the SoC and SOH to obtain the charging power state of multiple cells; wherein, for any cell among the multiple cells, the charging power state of the cell is less than or equal to the maximum charging power of the cell.

[0339] In one possible implementation, the battery is in a discharge state, and the power state is the discharge power state of multiple cells; the determining module 602 is specifically used for:

[0340] The discharge power state of multiple cells is obtained by fitting the SoC and SOH based on the second fitting model; wherein, for any cell among the multiple cells, the discharge power state of the cell is less than or equal to the maximum discharge power of the cell.

[0341] In one possible implementation, the determining module 602 is specifically used for:

[0342] Based on the power state of multiple battery cells, the power state of multiple battery cells is sorted.

[0343] The cell with the highest power state among multiple cells is identified as the first target cell, and the cell with the lowest power state among multiple cells is identified as the second target cell.

[0344] In one possible implementation, if the number of cells with the highest power state is greater than 1, the first target cell is determined to be the cell with the smallest SoC among the multiple cells with the highest power state.

[0345] If the number of cells with the lowest power state is greater than 1, the second target cell is determined to be the cell with the largest SoC among the multiple cells with the lowest power state.

[0346] In one possible implementation, the equalization circuit includes a switching matrix and a current converter;

[0347] The determination module is also used to: determine the target operating mode of the equalization circuit based on the types of the first target battery cell and the second target battery cell;

[0348] The control module 603 is specifically used to: control the equalization circuit to transfer the electrical energy of the first target cell to the second target cell based on the target operating mode, the switching matrix, and the current converter.

[0349] In one possible implementation, the control module 603 is specifically used for:

[0350] When the type of the first target cell is a single cell and the type of the second target cell is a single cell or a cell module, the target working mode is determined to be the cell-to-pack (CTP) mode.

[0351] When the type of the first target cell is a cell module and the type of the second target cell is a single cell or a cell module, the target operating mode is determined to be the battery pack-cell PTC mode.

[0352] In one possible implementation, the control module 603 is specifically used for:

[0353] When the target operating mode is CTP mode, the control switch matrix turns on the input terminal of the first target cell and the current converter, and turns on the output terminal of the second target cell and the current converter; the control current converter starts the boost operating mode and transfers the electrical energy of the first target cell to the second target cell;

[0354] When the target operating mode is PTC mode, the control switch matrix turns on the input terminal of the first target battery cell and the current converter, and turns on the output terminal of the second target battery cell and the current converter; the control current converter starts the buck operating mode and transfers the electrical energy of the first target battery cell to the second target battery cell.

[0355] In one possible implementation, the control module 603 is further configured to:

[0356] If the duration of the first target battery cell and the second target battery cell in the target state is greater than or equal to a preset duration, the control equalization circuit stops transferring the power of the first target battery cell to the second target battery cell; wherein, the target state includes: the difference in power state between the first target battery cell and the second target battery cell is less than a preset value.

[0357] In one possible implementation, the control module 603 is further configured to:

[0358] Initialize the battery management system;

[0359] Check if the battery monitoring unit is functioning properly;

[0360] When the battery monitoring unit is functioning normally, second battery data of multiple cells is collected. The second battery data includes at least one of the voltage and temperature values ​​of the multiple cells.

[0361] When the second battery data of multiple battery cells meets the preset requirements, the first battery data collected by the battery monitoring unit is acquired.

[0362] Alternatively, the battery protection program may be triggered if the battery monitoring unit malfunctions or if the second battery data of at least one of the multiple battery cells does not meet the preset requirements.

[0363] The battery management device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0364] Figure 7 Schematic diagram of the BMS system provided in this application Figure 2 .like Figure 7As shown, the BMS system 700 provided in this embodiment includes: a battery monitoring unit, an equalization circuit, at least one processor 701, and a memory 702. Optionally, the BMS system 700 further includes a communication component 703. The processor 701, memory 702, and communication component 703 are connected via a bus 704.

[0365] In a specific implementation, at least one processor 701 executes computer execution instructions stored in memory 702, causing at least one processor 701 to perform the above-described method.

[0366] The specific implementation process of processor 701 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0367] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0368] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0369] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0370] Figure 8 This is a structural diagram of the vehicle provided in this application. Figure 8 As shown, the vehicle 800 includes: a battery comprising multiple cells, and Figure 8The BMS system in China.

[0371] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0372] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0373] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0374] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0375] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0376] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0377] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0378] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0379] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0380] Finally, it should be noted that other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and alterations may be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery management method, characterized in that, An application is made in a battery management system, the battery management system including a battery monitoring unit and an balancing circuit, the battery monitoring unit being used to collect first battery data from multiple battery cells in the battery in real time, the balancing circuit being used to transfer electrical energy in the battery cells, the method including: The battery monitoring unit acquires the first battery data, which includes at least one of the voltage, current and temperature values ​​of each of the plurality of cells. Based on the first battery data, the power state of the plurality of cells is determined; Based on the power state of the multiple battery cells, a first target battery cell and a second target battery cell are determined among the multiple battery cells. The first target battery cell is the battery cell with the largest power state value among the multiple battery cells, and the second target battery cell is the battery cell with the smallest power state value among the multiple battery cells. If the power state difference between the first target cell and the second target cell is greater than or equal to a preset value, the equalization circuit is controlled to transfer the electrical energy of the first target cell to the second target cell.

2. The method according to claim 1, characterized in that, Determining the power state of the plurality of cells based on the first battery data includes: Obtain historical cycle data of the plurality of battery cells, wherein the historical cycle data includes at least one of the cumulative charge amount and the number of charge cycles of the plurality of battery cells; The historical cycle data and the first battery data are calculated using a preset filtering algorithm to obtain the real-time state of charge (SoC) of the multiple battery cells. The preset filtering algorithm includes at least one of the extended Kalman filter (EKF) algorithm and the unscented Kalman filter (UKF) algorithm. The real-time health status (SOH) of the multiple battery cells is obtained by calculating the historical cycle data based on a preset attenuation model. Based on the SoC and SOH of the plurality of battery cells, the power state of the plurality of battery cells is determined.

3. The method according to claim 2, characterized in that, The battery is in a charging state, and the power state refers to the charging power state of the plurality of cells. Determining the power state of the plurality of battery cells based on the SoC and the SOH includes: The charging power state of the multiple cells is obtained by fitting the SoC and the SOH based on the first fitting model. Specifically, for any one of the plurality of battery cells, the charging power state of the battery cell is less than or equal to the maximum charging power of the battery cell.

4. The method according to claim 2, characterized in that, The battery is in a discharge state, and the power state refers to the discharge power state of the plurality of cells. Determining the power state of the plurality of battery cells based on the SoC and the SOH includes: The discharge power state of the multiple cells is obtained by fitting the SoC and the SOH based on the second fitting model. Specifically, for any one of the plurality of battery cells, the discharge power state of the battery cell is less than or equal to the maximum discharge power of the battery cell.

5. The method according to claim 1, characterized in that, The step of determining the first target cell and the second target cell among the plurality of battery cells based on the power state of the plurality of battery cells includes: Based on the power state of the multiple battery cells, the power state of the multiple battery cells is sorted. The cell with the highest power state among the plurality of cells is determined as the first target cell, and the cell with the lowest power state among the plurality of cells is determined as the second target cell.

6. The method according to claim 5, characterized in that, If the number of cells with the highest power state is greater than 1, the first target cell is determined to be the cell with the smallest SoC among the multiple cells with the highest power state. If the number of cells with the lowest power state is greater than 1, the second target cell is determined to be the cell with the largest SoC among the multiple cells with the lowest power state.

7. The method according to any one of claims 1-6, characterized in that, The equalization circuit includes a switching matrix and a current converter; The control of the equalization circuit to transfer electrical energy from the first target cell to the second target cell includes: Based on the types of the first target battery cell and the second target battery cell, the target operating mode of the equalization circuit is determined. The equalization circuit is controlled to transfer the electrical energy of the first target cell to the second target cell based on the target operating mode, the switching matrix, and the current converter.

8. The method according to claim 7, characterized in that, Determining the target operating mode of the equalization circuit based on the types of the first target battery cell and the second target battery cell includes: When the type of the first target cell is a single cell and the type of the second target cell is a single cell or a cell module, the target working mode is determined to be the cell-to-pack (CTP) mode. When the type of the first target cell is a cell module and the type of the second target cell is a single cell or a cell module, the target operating mode is determined to be the battery pack-cell PTC mode.

9. The method according to claim 8, characterized in that, The control of the equalization circuit, based on the target operating mode, and based on the switching matrix and the current converter, transfers electrical energy from the first target cell to the second target cell, including: When the target operating mode is CTP mode, the switch matrix is ​​controlled to turn on the input terminals of the first target battery cell and the current converter, and to turn on the output terminals of the second target battery cell and the current converter; the current converter is controlled to start the boost operating mode and transfer the electrical energy of the first target battery cell to the second target battery cell; When the target operating mode is PTC mode, the switch matrix is ​​controlled to turn on the input terminals of the first target battery cell and the current converter, and to turn on the output terminals of the second target battery cell and the current converter; the current converter is controlled to start the buck operating mode and transfer the electrical energy of the first target battery cell to the second target battery cell.

10. The method according to claim 7, characterized in that, Also includes: If the duration of the first target cell and the second target cell in the target state is greater than or equal to a preset duration, the equalization circuit is controlled to stop transferring the electrical energy of the first target cell to the second target cell. The target state includes: the difference in power state between the first target cell and the second target cell is less than the preset value.

11. The method according to claim 7, characterized in that, Before acquiring the first battery data collected by the battery monitoring unit, the method further includes: Initialize the battery management system; Check whether the battery monitoring unit is functioning properly; When the battery monitoring unit is functioning normally, second battery data of the plurality of cells is collected. The second battery data includes at least one of the voltage value and temperature value of the plurality of cells. If the second battery data of the plurality of cells meets the preset requirements, the first battery data collected by the battery monitoring unit is acquired. Alternatively, if the battery monitoring unit malfunctions or the second battery data of at least one of the multiple battery cells does not meet the preset requirements, the battery protection program is triggered.

12. A battery management device, characterized in that, Applied to a battery management system, the battery management system includes a battery monitoring unit and an balancing circuit. The battery monitoring unit is used to collect first battery data from multiple battery cells in the battery in real time, and the balancing circuit is used to transfer electrical energy in the battery cells. The battery management device includes: The acquisition module is used to acquire the first battery data collected by the battery monitoring unit, wherein the first battery data includes at least one of the voltage value, current value and temperature value of each of the plurality of cells; The determining module is configured to determine the power state of the plurality of cells based on the first battery data; and to determine a first target cell and a second target cell among the plurality of cells based on the power state of the plurality of cells, wherein the first target cell is the cell with the largest power state value among the plurality of cells, and the second target cell is the cell with the smallest power state value among the plurality of cells. The control module is used to control the equalization circuit to transfer the electrical energy of the first target cell to the second target cell when the power state difference between the first target cell and the second target cell is greater than or equal to a preset value.

13. A battery management system (BMS), characterized in that, include: The battery monitoring unit, the equalization circuit, the memory, and the processor are used to collect first battery data of multiple cells in the battery in real time, and the equalization circuit is used to transfer electrical energy in the cells. The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-11.

14. A vehicle, characterized in that, include: A battery comprising multiple cells, and a BMS system as described in claim 13.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-11.

16. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in any one of claims 1-11.

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