A power battery device and a current control method of a power battery

Abstract

The application provides a power battery device and a current control method of a power battery, and relates to the technical field of batteries. The power battery device comprises a plurality of battery cell units, a voltage detection circuit and a controller. The plurality of battery cell units are connected in series. Each battery cell unit is connected with a parallel adjustable resistor. The battery cell units are connected with the voltage detection circuit. The voltage detection circuit is used for acquiring the voltage of the battery cell units. The controller is connected with the adjustable resistor and the voltage detection circuit. The controller is used for obtaining the state of charge data of the battery cell units based on the voltage of the battery cell units. The adjustable resistor is adjusted according to the reference state of charge data and the state of charge data of the battery cell units, so as to adjust the charging and discharging current of the battery cell units. The power battery device can improve the consistency of the battery cells and prolong the service life of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a power battery device and a current control method for the power battery. Background Technology

[0002] Generally, a power battery pack includes multiple individual battery cells. The power battery pack is charged using constant current charging, which means that the charging current for each cell in the power battery pack is the same. However, due to the differences between individual cells, charging under the current constant current state will cause some cells with severe aging to age further, resulting in poor cell consistency and reduced battery life. Summary of the Invention

[0003] The purpose of this application is to provide a power battery device and a current control method for the power battery, which can achieve the technical effects of improving cell consistency and extending battery life.

[0004] In a first aspect, this application provides a power battery device, including multiple battery cell units, a voltage detection circuit, and a controller;

[0005] The plurality of battery cell units are connected in series, each battery cell unit is connected in parallel with an adjustable resistor, and the battery cell unit is connected to the voltage detection circuit, which is used to acquire the voltage of the battery cell unit. The controller is connected to the adjustable resistor and the voltage detection circuit respectively; the controller is used for:

[0006] The state of charge data of the battery cell is obtained based on the voltage of the battery cell.

[0007] The adjustable resistor is adjusted based on the reference state of charge data and the state of charge data of the battery cell to regulate the charging and discharging current of the battery cell.

[0008] In the above implementation process, each cell unit is connected in parallel with an adjustable resistor and equipped with a voltage detection circuit. The charging and discharging current of the cell unit can be adjusted through the adjustable resistor. Furthermore, the controller of the power battery device acquires the state of charge (SOC) data of each cell unit and adjusts the adjustable resistor differently based on the SOC data of each cell unit to regulate the charging and discharging current of each cell unit. This achieves differentiated charging and discharging of the cell units to avoid overcharging or over-discharging and ensure that the SOC of multiple cell units remains consistent. Thus, the current processing method of this battery assembly achieves differentiated charging of each cell unit, ensuring the consistency of each cell unit and thereby improving the technical effect of improving battery life.

[0009] Furthermore, the state of charge data includes real-time cell voltage data, the reference state of charge data includes reference voltage data, and the controller is further configured to:

[0010] The real-time cell voltage data of the cell unit is obtained based on the voltage of the cell unit;

[0011] Based on the reference voltage data and the real-time cell voltage data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

[0012] In the above implementation process, the state of charge is characterized by the voltage of the battery cell, and the current regulation data is determined based on the reference voltage data and the real-time battery cell voltage data to differentiate the charging and discharging current of the battery cell. The real-time battery cell voltage data is detected in real time, and the current regulation data can be adjusted in real time to realize the real-time adjustment of the charging and discharging current of the battery cell, which more effectively ensures the consistency of each battery cell.

[0013] Furthermore, the controller is also used for:

[0014] The reference voltage data is obtained by averaging the real-time cell voltage data of the multiple cell units.

[0015] The voltage difference data is obtained by performing difference processing between the reference voltage data and the real-time cell voltage data of the cell unit;

[0016] The current adjustment data is determined based on the voltage difference data.

[0017] In the above implementation process, the current adjustment data is determined based on the difference between the reference voltage data and the real-time cell voltage data. The larger the difference, the greater the adjustment range of the current adjustment data, so as to ensure the consistency of cells between each cell unit.

[0018] Furthermore, the current regulation data includes a current proportional coefficient. If the power battery device is in a charging state, the controller is also used to:

[0019] If the real-time cell voltage data of the cell unit is greater than the reference voltage data, then the current proportionality coefficient is determined to be less than 1, and the current proportionality coefficient is negatively correlated with the voltage difference data.

[0020] If the real-time cell voltage data of the cell unit is less than the reference voltage data, then the current proportionality coefficient is determined to be greater than 1, and the current proportionality coefficient is positively correlated with the voltage difference data.

[0021] In the above implementation process, during charging, if the real-time cell voltage data is greater than the reference voltage data, it indicates that the capacity of the cell unit is too low. In this case, the charging current of the cell unit needs to be reduced, so that the current ratio coefficient is less than 1. The larger the difference, the lower the capacity. The current ratio coefficient and the voltage difference data are negatively correlated. If the real-time cell voltage data is less than the reference voltage data, it indicates that the capacity of the cell unit is too high. In this case, the charging current of the cell unit needs to be increased, so that the current ratio coefficient is greater than 1. The larger the difference, the higher the capacity. The current ratio coefficient and the voltage difference data are positively correlated.

[0022] Furthermore, the current regulation data includes a current proportional coefficient. If the power battery device is in a discharging state, the controller is also used to:

[0023] If the real-time cell voltage data of the cell unit is greater than the reference voltage data, then the current proportionality coefficient is determined to be greater than 1, and the current proportionality coefficient is positively correlated with the voltage difference data.

[0024] If the real-time cell voltage data of the cell unit is less than the reference voltage data, then the current proportionality coefficient is determined to be less than 1, and the current proportionality coefficient is negatively correlated with the voltage difference data.

[0025] In the above implementation process, if the real-time cell voltage data is greater than the reference voltage data during discharge, it indicates that the capacity of the cell unit is too high. In this case, the discharge current of the cell unit needs to be increased, so that the current ratio coefficient is greater than 1. The larger the difference, the higher the capacity. The current ratio coefficient is positively correlated with the voltage difference data. If the real-time cell voltage data is less than the reference voltage data, it indicates that the capacity of the cell unit is too low. In this case, the discharge current of the cell unit needs to be decreased, so that the current ratio coefficient is less than 1. The larger the difference, the lower the capacity. The current ratio coefficient is negatively correlated with the voltage difference data.

[0026] Furthermore, the controller is also used for:

[0027] Standard deviation data of voltage is obtained by performing standard deviation processing on the real-time cell voltage data of the multiple cell units.

[0028] The voltage threshold is determined based on the voltage standard deviation data;

[0029] If the voltage difference data is greater than the voltage threshold, then the adjustable resistor of the battery cell is adjusted according to the current adjustment data;

[0030] If the voltage difference data is less than or equal to the voltage threshold, the adjustable resistor of the battery cell will not be adjusted according to the current adjustment data.

[0031] In the above implementation process, the voltage threshold is determined by the voltage standard deviation data. The charging and discharging current of the cell unit is adjusted only when the voltage difference data is greater than the voltage threshold. This reduces the current adjustment frequency of the cell unit while ensuring cell consistency, thereby reducing the power consumption of the power battery device.

[0032] Furthermore, the state of charge data includes historical cell voltage drop data, the reference state of charge data includes reference voltage drop data, and the controller is also used to:

[0033] The historical cell voltage drop data of the cell unit is obtained based on the voltage of the cell unit;

[0034] Based on the reference voltage drop data and the historical cell voltage drop data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

[0035] In the above implementation process, the state of charge is characterized by the historical cell voltage drop data of the cell unit, and the current regulation data is determined based on the reference voltage drop data and the historical cell voltage drop data to differentiate the charging and discharging current of the cell unit. Thus, before the power battery starts working, the current regulation data is preset based on the historical cell voltage drop data, and the charging and discharging current of each cell unit is differentiated. While ensuring the consistency of the cells, the power consumption of the power battery device is effectively reduced, and the range is improved.

[0036] Furthermore, the controller is also used for:

[0037] The baseline voltage drop data is obtained by averaging the historical cell voltage drop data of the multiple cell units.

[0038] The current regulation data is determined based on the reference voltage drop data and the historical cell voltage drop data of the cell unit.

[0039] In the above implementation process, the current adjustment data is determined based on the difference between the reference voltage drop data and the historical cell voltage drop data. The greater the difference, the greater the adjustment range of the current adjustment data, so as to ensure the consistency of each cell unit.

[0040] Furthermore, the current regulation data includes a current proportionality coefficient, and the controller is also used to:

[0041] Get the preset multiple data;

[0042] The multiple voltage drop data is determined based on the baseline voltage drop data and the preset multiple data;

[0043] If the historical cell voltage drop data is greater than the multiple voltage drop data, then the current ratio coefficient is determined to be less than 1, and the current ratio coefficient is negatively correlated with the preset multiple data.

[0044] If the historical cell voltage drop data is less than the multiple voltage drop data, then the current ratio coefficient is determined to be greater than 1, and the current ratio coefficient is positively correlated with the preset multiple data.

[0045] In the above implementation process, the difference between the reference voltage drop data and the historical cell voltage drop data is determined by the size of the cell voltage drop data and the multiple voltage drop data. The larger the preset multiple used for the multiple voltage drop data, the larger the difference and the larger the adjustment range of the current regulation data, so as to ensure the consistency of each cell unit.

[0046] Furthermore, the current regulation data includes a current proportionality coefficient, and the controller is also used to:

[0047] The voltage drop difference data is obtained by performing difference processing between the reference voltage drop data and the historical cell voltage drop data of the cell unit.

[0048] If the historical cell voltage drop data is greater than the reference voltage drop data, then the current proportional coefficient is determined to be less than 1, and the voltage drop difference data is negatively correlated with the current proportional coefficient.

[0049] If the historical cell voltage drop data is less than the reference voltage drop data, then the current proportionality coefficient is determined to be greater than 1, and the voltage drop difference data is positively correlated with the current proportionality coefficient.

[0050] In the above implementation process, the difference between the reference voltage drop data and the historical cell voltage drop data is determined by the magnitude of the difference. The larger the voltage drop difference, the greater the difference, and the greater the adjustment range of the current regulation data, so as to ensure the consistency of each cell unit.

[0051] Furthermore, the state of charge data includes real-time cell voltage data and historical cell voltage drop data, and the reference state of charge data includes reference voltage data and reference voltage drop data. The controller is also used for:

[0052] Based on the reference voltage data and the real-time cell voltage data of the cell unit, the first current adjustment data is determined;

[0053] The second current adjustment data is determined based on the reference voltage drop data and the historical cell voltage drop data of the cell unit;

[0054] The current adjustment data is determined based on the minimum value between the first current adjustment data and the second current adjustment data, and the adjustable resistor is adjusted based on the current adjustment data.

[0055] In the above implementation process, the first current adjustment data is determined by the reference voltage data and the real-time cell voltage data, the second current adjustment data is determined by the reference voltage drop data and the historical cell voltage drop data, and the final current adjustment data is determined by the minimum value between the two. While taking into account the power battery power consumption, the consistency of cells between each cell unit is effectively guaranteed.

[0056] Furthermore, the battery cell unit also includes an electronic switch, which is connected in series with the adjustable resistor, and controls the on / off state of the adjustable resistor through the electronic switch.

[0057] In the above implementation process, by connecting an electronic switch in series with an adjustable resistor, the connection between the battery cell and the adjustable resistor can be disconnected without adjusting the charging and discharging current of the battery cell, thus avoiding the shunting effect of the adjustable resistor on the battery cell, thereby reducing the power consumption of the power battery device and improving the driving range.

[0058] Secondly, this application provides a current control method for a power battery, applied to the power battery device described in any one of the first aspects, the control method comprising:

[0059] The state of charge data of the battery cell is obtained based on the voltage value of the battery cell.

[0060] The adjustable resistor is adjusted based on the reference state of charge data and the state of charge data of the battery cell to regulate the charging and discharging current of the battery cell.

[0061] Other features and advantages disclosed in this application will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the above-described technology disclosed in this application.

[0062] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0063] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0064] Figure 1 A structural block diagram of a power battery device provided in an embodiment of this application;

[0065] Figure 2A circuit diagram of a power battery device provided in an embodiment of this application;

[0066] Figure 3 This is a schematic diagram of the structure of the power battery device provided in the embodiments of this application;

[0067] Figure 4 A schematic flowchart of the current control method for a power battery provided in an embodiment of this application;

[0068] Figure 5 A schematic diagram of the cell voltage drop provided in an embodiment of this application;

[0069] Figure 6 A schematic diagram of the charging cutoff voltage provided in an embodiment of this application;

[0070] Figure 7 A schematic diagram of the discharge cutoff voltage provided in the embodiments of this application;

[0071] Figure 8 This is a schematic diagram of the current proportionality coefficient k provided in an embodiment of this application. Detailed Implementation

[0072] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0073] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0074] Generally, a power battery pack includes multiple cells. Due to variations in the manufacturing process (such as weight differences in the active materials of the cathode and anode, and fluctuations in the electrolyte injection volume), the parameters of each cell are actually different, such as capacity, resistance, and voltage. Furthermore, the different positions of each cell within the power battery pack lead to temperature differences during use, further amplifying the differences between cells. As usage time increases, the consistency between batteries deteriorates further. These differences in consistency between batteries include the following two aspects:

[0075] Firstly, there's the difference in cell capacity: For example, if the weight of the anode and cathode is slightly higher than the upper limit during coating, the cell capacity might be 102Ah (hypothetical value). If the weight is at the average, the cell capacity might be 100Ah (hypothetical value). If the weight is slightly lower, the cell capacity might be 98Ah (hypothetical value). These three batteries will be randomly installed in the same module. During use, the charging current will be constant (in series), let's say 100A. However, for the 102Ah cell, the charging rate will be <1C, while for the 98Ah cell, the charging rate will be >1C. The two have different fast charging rates, and the battery with the higher rate ages faster. Therefore, over time, the consistency of the cells deteriorates.

[0076] Second, there is the difference in SOC of the cells: For example, in a pack, the difference in SOC consistency can cause a loss in cell capacity. For example, when the system displays 0% SOC, the actual situation is that one cell is at 0% while the other cells may have 0-2% SOC. Therefore, during the subsequent charging process, the cells can only be charged to a maximum of 98% SOC. When a single cell reaches 100% SOC, charging stops, and the system displays a full charge of 100% SOC; but in reality, there is only 98% SOC.

[0077] The combined effect of the above two factors may lead to a loss of cell capacity, resulting in incomplete release; or some cells may have a higher depth of charge and discharge than other cells, which accelerates cell aging and further exacerbates the capacity difference between cells, leading to a loss of capacity in a consistent manner between cells and a shortened lifespan of the battery pack.

[0078] To address the aforementioned technical problems, this application provides a power battery device and a current control method for the power battery. In the power battery device, each cell unit is connected to an adjustable resistor. To address the differences in the state of charge (SOC) of each cell unit, the adjustable resistor is used to shunt and adjust the charging and discharging current of the cell unit, ensuring a consistent SOC. Thus, by implementing differentiated charging and discharging for each cell unit, the power battery device guarantees the consistency of each cell unit, thereby improving battery lifespan.

[0079] For example, in this embodiment of the application, SOC (State of Charge) is a core parameter reflecting the remaining capacity of the battery, defined as the percentage of the battery's current remaining capacity to its usable capacity, with a value ranging from 0% to 100%. Its calculation method is as follows:

[0080] SOC = (Current Capacity / Available Capacity) × 100%;

[0081] Usable capacity refers to the maximum amount of electricity that the battery can release under standard conditions. When SOC = 0%, the battery is fully discharged; when SOC = 100%, the battery is fully charged.

[0082] Please see Figures 1 to 3 , Figure 1 This is a structural block diagram of a power battery device provided in an embodiment of this application. Figure 2 This is a schematic diagram of the circuit structure of a power battery device provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a power battery device provided in an embodiment of this application; the power battery device includes multiple battery cell units 110, a voltage detection circuit 200, and a controller 300;

[0083] For example, multiple battery cell units 110 are connected in series, each battery cell unit 110 is connected in parallel with an adjustable resistor 120, and the battery cell unit 110 is connected to a voltage detection circuit 200, which is used to acquire the voltage of the battery cell unit 110. The controller 300 is connected to the adjustable resistor 120 and the voltage detection circuit 200 respectively; the controller 300 is used for:

[0084] The state of charge data of the battery cell 110 is obtained based on the voltage of the battery cell 110;

[0085] Adjust the adjustable resistor 120 according to the reference state of charge data and the state of charge data of the cell 110 to adjust the charging and discharging current of the cell 110.

[0086] For example, the controller 300 can be a battery management system (BMS) of a power battery device, which can intelligently manage and maintain each cell unit 110, monitor the status of the battery, prevent the battery from overcharging and over-discharging, and extend the battery's service life.

[0087] The controller 300 can also be a control processor; for example, it can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor, or the control processor can be any conventional processor, etc.

[0088] The controller 300 is connected to the adjustable resistor 120 and the voltage detection circuit 200. The voltage detection circuit 200 acquires the voltage of the battery cell 110, allowing for the detection and evaluation of the state of charge of the battery cell 110. The adjustable resistor 120 is connected in parallel with the battery cell 110. Adjusting the resistance of the adjustable resistor 120 regulates its shunt current, thereby regulating the charging and discharging current of the battery cell 110. For example, when the bus current of the power battery device is constant:

[0089] Increasing the impedance of the adjustable resistor 120 reduces the current in the adjustable resistor 120, which in turn increases the charging and discharging current of the corresponding battery cell unit; decreasing the impedance of the adjustable resistor 120 increases the current in the adjustable resistor 120, which in turn decreases the charging and discharging current of the corresponding battery cell unit 110.

[0090] For example, the power battery device provided in this application embodiment may include multiple sensors in addition to the voltage detection circuit 200, to acquire parameters such as battery current and temperature as input data for state of charge estimation. For example, the voltage detection accuracy of the voltage detection circuit 200 can reach ±1mV, the current detection uses a Hall sensor or shunt, and the temperature detection relies on a thermistor or thermocouple, etc.

[0091] The sensors in the power battery device described in the embodiments of this application are not limited to the sensors described above, but can also be applied to all sensors used to detect the state of charge of the battery cell. For the sake of brevity, the following embodiments mainly describe the voltage detection circuit 200, and calculate and evaluate the state of charge of the battery cell using the voltage value of the battery cell (e.g., real-time voltage, voltage drop, etc.) for illustrative purposes. The voltage detection circuit 200 can be connected in parallel with the battery cell unit 110, thereby acquiring the voltage data of the battery cell unit 110 through a voltage detector.

[0092] For example, the controller 300 can calculate and evaluate the state of charge of the battery cell 110 by acquiring the voltage value of the battery cell 110, and obtain state of charge data based on the voltage value of the battery cell 110.

[0093] For example, the reference state of charge data can be preset data, which can be obtained by testing the power battery device or calculated based on the historical usage data of the power battery device; it should be noted that the preset data can also be obtained in other ways not mentioned, which is only an example and not a limitation.

[0094] For example, the reference state of charge data can also be obtained by averaging or weighted averaging the state of charge data of multiple cell units 110.

[0095] The reference state of charge data can be used as a benchmark. When there is a difference between the state of charge data of the cell unit 110 and the reference state of charge data, the charging and discharging current of the cell unit 110 is adjusted so that the state of charge of the cell unit 110 is consistent with that of other cell units 110, thus ensuring cell consistency.

[0096] For example, the battery power unit also includes a connector 111, two adjacent battery cells 110 are connected in series through the connector 111, and one end of the adjustable resistor 120 is connected to the connector 111; wherein, the connector 111 serves as a busbar component of the battery cell 110, and may be a connection terminal, a connection line, etc., which is only an example and not a limitation.

[0097] For example, the power battery device provided in the embodiments of this application can be combined into a larger battery pack structure by means of series and / or parallel connection, which is only an example and not a limitation.

[0098] In this embodiment, each cell unit is connected in parallel with an adjustable resistor and equipped with a voltage detection circuit 200. The charging and discharging current of the cell unit can be adjusted through the adjustable resistor. Furthermore, the controller of the power battery device acquires the state of charge (SOC) data of each cell unit and adjusts the adjustable resistor differently based on the SOC data of each cell unit to regulate the charging and discharging current of each cell unit. This achieves differentiated charging and discharging of the cell units to avoid overcharging or over-discharging and ensures that the SOC of multiple cell units remains consistent. Thus, the current processing method of this battery assembly achieves differentiated charging of each cell unit, ensuring the consistency of each cell unit and thereby improving the battery life.

[0099] In some embodiments, the state-of-charge data includes real-time cell voltage data, and the reference state-of-charge data includes reference voltage data. The controller is further configured to:

[0100] The real-time cell voltage data of the cell unit is obtained based on the voltage of the cell unit.

[0101] Based on the reference voltage data and the real-time cell voltage data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

[0102] For example, the current adjustment data can be proportional adjustment or numerical adjustment;

[0103] When the current regulation data is proportional, the current regulation data is used to proportionally amplify or proportionally reduce the charging and discharging current of the battery cell 110 by setting a proportional coefficient.

[0104] When the current regulation data is numerical, the current regulation data is adjusted by setting multiple values ​​and calculating the addition and subtraction of the charging and discharging current of the cell unit 110 based on these multiple values, thereby adjusting the charging and discharging current of the cell unit 110 to increase or decrease.

[0105] It should be understood that, for the sake of brevity, the following embodiments are mainly described using current adjustment data as a proportional adjustment, and are used as examples for illustration.

[0106] For example, the real-time cell voltage data can be a voltage value acquired in real time or a voltage value acquired at preset intervals. The preset intervals can be set according to actual needs, such as 1 minute, 5 minutes, 1 minute, etc. The acquisition frequency of the real-time cell voltage data corresponds to the charging and discharging current adjustment frequency of the cell unit 110. The higher the current adjustment frequency, the higher the acquisition frequency of the corresponding real-time cell voltage data.

[0107] For example, the state of charge data is characterized by the real-time cell voltage data of the cell unit 110, that is, the state of charge data is represented by the cell voltage data; thus, by detecting the voltage value of the cell unit 110 in real time and obtaining the real-time cell voltage data, the state of charge of the cell unit 110 can be characterized.

[0108] For example, after the state of charge data is characterized by the real-time cell voltage data of the cell unit 110, the reference voltage data is obtained by performing calculation processing (e.g., averaging, weighted averaging, etc.) on the real-time cell voltage data of multiple cell units 110, and the reference state of charge data can be characterized by the reference voltage data.

[0109] By using the above method, the state of charge of the detected cell unit 110 is converted into the voltage value of the detected cell unit 110, which simplifies data processing and the circuit structure of the power battery device, and effectively ensures cell consistency without increasing manufacturing costs.

[0110] The state of charge is characterized by the voltage of the battery cell, and the current regulation data is determined based on the reference voltage data and the real-time battery cell voltage data to differentiate the charging and discharging current of the battery cell. The real-time battery cell voltage data is detected in real time, and the current regulation data can be adjusted in real time to realize the real-time regulation of the charging and discharging current of the battery cell, which more effectively ensures the consistency of each battery cell.

[0111] In some embodiments, the controller is further configured to:

[0112] A reference voltage data is obtained by averaging the real-time cell voltage data of multiple cell units.

[0113] The voltage difference data is obtained by performing difference processing between the reference voltage data and the real-time cell voltage data of the cell unit;

[0114] The current adjustment data is determined based on the voltage difference data.

[0115] For example, the real-time cell voltage data of multiple cell units 110 are averaged, and the average voltage is calculated based on the real-time cell voltage data of multiple cell units 110 to obtain reference voltage data; then, the charging and discharging current of cell unit 110 is adjusted based on the difference between the reference voltage data and the real-time cell voltage data of cell unit 110, and the larger the difference, the larger the adjustment range.

[0116] The current adjustment data is determined based on the difference between the reference voltage data and the real-time cell voltage data. The larger the difference, the greater the adjustment range of the current adjustment data, so as to ensure the consistency of cells between each cell unit.

[0117] In some embodiments, the current regulation data includes a current proportionality coefficient. If the power battery device is in a charging state, the controller is further configured to:

[0118] If the real-time cell voltage data of the cell unit is greater than the reference voltage data, then the current proportional coefficient is determined to be less than 1, and the current proportional coefficient is negatively correlated with the voltage difference data.

[0119] If the real-time cell voltage data of the battery cell is less than the reference voltage data, then the current proportionality coefficient is determined to be greater than 1, and the current proportionality coefficient is positively correlated with the voltage difference data.

[0120] For example, in the charging state:

[0121] If the real-time cell voltage data of cell unit 110 is greater than the reference voltage data, it indicates that the current cell unit 110 is more aged and the charging speed is faster. It is necessary to reduce the charging current of cell unit 110 (i.e., set the current ratio coefficient to be less than 1) to reduce the charging speed. The larger the voltage difference data, the greater the adjustment range of the current adjustment data.

[0122] If the real-time cell voltage data of cell unit 110 is less than the reference voltage data, it indicates that the current aging degree of cell unit 110 is low and the charging speed is slow. It is necessary to increase the charging current of cell unit 110 (i.e., set the current ratio coefficient to be greater than 1) to improve the charging speed. The larger the voltage difference data, the greater the adjustment range of the current adjustment data.

[0123] Optionally, if the real-time cell voltage data of the cell unit 110 is equal to the reference voltage data, then there is no need to adjust the charging current of the cell unit 110, which is equivalent to the current proportional coefficient being equal to 1.

[0124] During charging, if the real-time cell voltage data is greater than the reference voltage data, it indicates that the capacity of the cell unit is too low. In this case, the charging current of the cell unit needs to be reduced, so that the current ratio coefficient is less than 1. The larger the difference, the lower the capacity. The current ratio coefficient and the voltage difference data are negatively correlated. If the real-time cell voltage data is less than the reference voltage data, it indicates that the capacity of the cell unit is too high. In this case, the charging current of the cell unit needs to be increased, so that the current ratio coefficient is greater than 1. The larger the difference, the higher the capacity. The current ratio coefficient and the voltage difference data are positively correlated.

[0125] In some embodiments, the current regulation data includes a current proportionality coefficient. If the power battery device is in a discharging state, the controller is further configured to:

[0126] If the real-time cell voltage data of the cell unit is greater than the reference voltage data, then the current proportional coefficient is determined to be greater than 1, and the current proportional coefficient is positively correlated with the voltage difference data.

[0127] If the real-time cell voltage data of the battery cell is less than the reference voltage data, then the current proportionality coefficient is determined to be less than 1, and the current proportionality coefficient is negatively correlated with the voltage difference data.

[0128] For example, in the discharge state:

[0129] If the real-time cell voltage data of cell unit 110 is greater than the reference voltage data, it indicates that the current aging degree of cell unit 110 is low and the discharge speed is slow. It is necessary to increase the discharge current of cell unit 110 (i.e., set the current proportional coefficient to be greater than 1) to increase the discharge speed. The larger the voltage difference data, the greater the adjustment range of the current adjustment data.

[0130] If the real-time cell voltage data of cell unit 110 is less than the reference voltage data, it indicates that the current cell unit 110 is aging and the discharge speed is fast. It is necessary to reduce the discharge current of cell unit 110 (i.e., set the current ratio coefficient to be less than 1) to reduce the charging speed. The larger the voltage difference data, the greater the adjustment range of the current adjustment data.

[0131] Optionally, if the real-time cell voltage data of the cell unit 110 is equal to the reference voltage data, then there is no need to adjust the discharge current of the cell unit 110, which is equivalent to the current proportional coefficient being equal to 1.

[0132] During discharge, if the real-time cell voltage data is greater than the reference voltage data, it indicates that the capacity of the cell unit is too high. In this case, the discharge current of the cell unit needs to be increased, so that the current proportionality coefficient is greater than 1. The larger the difference, the higher the capacity. The current proportionality coefficient is positively correlated with the voltage difference data. If the real-time cell voltage data is less than the reference voltage data, it indicates that the capacity of the cell unit is too low. In this case, the discharge current of the cell unit needs to be decreased, so that the current proportionality coefficient is less than 1. The larger the difference, the lower the capacity. The current proportionality coefficient is negatively correlated with the voltage difference data.

[0133] In some embodiments, the controller is further configured to:

[0134] Standard deviation data of voltage is obtained by processing the standard deviation of real-time cell voltage data of multiple cell units.

[0135] Determine the voltage threshold based on the voltage standard deviation data;

[0136] If the voltage difference data is greater than the voltage threshold, the adjustable resistor of the cell unit will be adjusted according to the current adjustment data.

[0137] If the voltage difference data is less than or equal to the voltage threshold, the adjustable resistor of the cell unit will not be adjusted according to the current adjustment data.

[0138] The voltage threshold is determined by the voltage standard deviation data. The charging and discharging current of the battery cell is adjusted only when the voltage difference data is greater than the voltage threshold. This reduces the current adjustment frequency of the battery cell while ensuring the consistency of the battery cells, thereby reducing the power consumption of the power battery device.

[0139] In some embodiments, the state-of-charge data includes historical cell voltage drop data, the reference state-of-charge data includes reference voltage drop data, and the controller is further configured to:

[0140] Historical cell voltage drop data of the cell unit is obtained based on the voltage of the cell unit;

[0141] Based on the reference voltage drop data and the historical cell voltage drop data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

[0142] For example, in a power battery device, the controller 300 can detect the voltage value of each cell unit 110 in real time and use the voltage value as a basis to determine the state of charge of each battery. For example, it can extract the voltage change curves of the power battery device after full charging and discharging, and calculate the voltage drop of each cell unit 110 as historical cell voltage drop data. When the historical cell voltage drop data is large, it indicates that the capacity of the cell unit 110 is low and the aging condition is serious. When the historical cell voltage drop data is small, it indicates that the capacity of the cell unit 110 is high and the aging condition is low.

[0143] For example, after the state of charge data is characterized by the historical cell voltage drop data of the cell unit 110, the reference voltage drop data is obtained by performing calculation processing (e.g., mean processing, weighted average processing, etc.) on the historical cell voltage drop data of multiple cell units 110, and the reference state of charge data can be characterized by the reference voltage drop data.

[0144] By characterizing the state of charge using historical cell voltage drop data, and determining current regulation data based on reference voltage drop data and historical cell voltage drop data, the charging and discharging current of the cell units can be adjusted differently. Thus, before the power battery starts working, the current regulation data is preset based on historical cell voltage drop data, and the charging and discharging current of each cell unit is adjusted differently. This effectively reduces the power consumption of the power battery device and improves the driving range while ensuring cell consistency.

[0145] In some embodiments, the controller is further configured to:

[0146] A baseline voltage drop data is obtained by averaging the historical cell voltage drop data of multiple cell units.

[0147] The current regulation data is determined based on the reference voltage drop data and the historical cell voltage drop data of the cell unit.

[0148] For example, the current regulation data is determined based on the difference between the reference voltage drop data and the historical cell voltage drop data. The greater the difference, the greater the adjustment range of the current regulation data, so as to ensure the cell consistency of each cell unit.

[0149] In some embodiments, the current regulation data includes a current proportionality coefficient, and the controller is further configured to:

[0150] Get the preset multiple data;

[0151] Determine the multiple voltage drop data based on the baseline voltage drop data and the preset multiple data;

[0152] If the historical cell voltage drop data is greater than the multiple voltage drop data, then the current proportional coefficient is determined to be less than 1, and the current proportional coefficient is negatively correlated with the preset multiple data.

[0153] If the historical cell voltage drop data is less than the multiple voltage drop data, then the current proportional coefficient is determined to be greater than 1, and the current proportional coefficient is positively correlated with the preset multiple data.

[0154] For example, a preset multiple data x can be set; the multiple voltage drop data can be calculated as the product of the reference voltage drop data and the preset multiple data x, or as the product of the reference voltage drop data and (1+x); the following embodiment uses the product of the reference voltage drop data and (1+x) as the multiple voltage drop data for illustration:

[0155] If the historical cell voltage drop data is greater than the multiple voltage drop data, the current proportional coefficient is greater than 1. The larger x is, the larger the current proportional coefficient is.

[0156] If the historical cell voltage drop data is less than the multiple of the voltage drop data, the current proportionality coefficient is less than 1. The larger x is, the smaller the current proportionality coefficient is.

[0157] Optionally, if the historical cell voltage drop data is equal to a multiple of the voltage drop data, then there is no need to adjust the charging and discharging current of the cell unit 110, which is equivalent to the current proportional coefficient being equal to 1.

[0158] The difference between the reference voltage drop data and the historical cell voltage drop data is determined by the magnitude of the cell voltage drop data and the multiple voltage drop data. The larger the preset multiple used for the multiple voltage drop data, the greater the difference, and the greater the adjustment range of the current regulation data, so as to ensure the consistency of each cell unit.

[0159] In some embodiments, the current regulation data includes a current proportionality coefficient, and the controller is further configured to:

[0160] The voltage drop difference data is obtained by performing difference processing between the reference voltage drop data and the historical cell voltage drop data of the cell unit;

[0161] If the historical cell voltage drop data is greater than the reference voltage drop data, then the current proportional coefficient is determined to be less than 1, and the voltage drop difference data is negatively correlated with the current proportional coefficient.

[0162] If the historical cell voltage drop data is less than the baseline voltage drop data, then the current proportional coefficient is determined to be greater than 1, and the voltage drop difference data is positively correlated with the current proportional coefficient.

[0163] The difference between the reference voltage drop data and the historical cell voltage drop data is determined by the magnitude of the difference. The larger the voltage drop difference, the greater the difference, and the greater the adjustment range of the current regulation data, so as to ensure the consistency of each cell unit.

[0164] In some embodiments, the state-of-charge data includes real-time cell voltage data and historical cell voltage drop data, and the reference state-of-charge data includes reference voltage data and reference voltage drop data. The controller is further configured to:

[0165] The first current adjustment data is determined based on the reference voltage data and the real-time cell voltage data of the cell unit.

[0166] The second current adjustment data is determined based on the reference voltage drop data and the historical cell voltage drop data of the cell unit;

[0167] The current adjustment data is determined based on the minimum value between the first current adjustment data and the second current adjustment data, and the adjustable resistor is adjusted according to the current adjustment data.

[0168] For example, the first current regulation data is determined by reference voltage data and real-time cell voltage data, the second current regulation data is determined by reference voltage drop data and historical cell voltage drop data, and the final current regulation data is determined by the minimum value between the two. This effectively ensures the consistency of cells between each cell unit while taking into account the power battery power consumption.

[0169] It should be noted that the specific implementation methods of "determining the first current adjustment data based on the reference voltage data and the real-time cell voltage data of the cell unit" and "determining the second current adjustment data based on the reference voltage drop data and the historical cell voltage drop data of the cell unit" have been described in the above embodiments, and will not be repeated here to avoid repetition.

[0170] In some embodiments, the battery cell unit further includes an electronic switch connected in series with an adjustable resistor, which controls the on / off state of the adjustable resistor.

[0171] For example, the electronic switch can be a semiconductor device such as a MOSFET or an IGBT. The electronic switch is connected in series with an adjustable resistor, and the switching on and off of the electronic switch controls the switching on and off of the adjustable resistor.

[0172] By connecting an electronic switch in series with an adjustable resistor, the connection between the battery cell and the adjustable resistor can be disconnected without adjusting the charging and discharging current of the battery cell. This avoids the shunting effect of the adjustable resistor on the battery cell, thereby reducing the power consumption of the power battery device and increasing the driving range.

[0173] This application also provides a current control method for a power battery, which can be applied to... Figures 1 to 3 The power battery device; please refer to Figure 4 , Figure 4 This is a flowchart illustrating a current control method for a power battery provided in an embodiment of this application. The current control method includes the following steps:

[0174] S100: Obtain the state of charge data of the battery cell based on the voltage value of the battery cell;

[0175] S200: Adjust the adjustable resistor based on the reference state of charge data and the state of charge data of the cell to regulate the charging and discharging current of the cell.

[0176] In some embodiments, the state of charge data includes real-time cell voltage data, and the reference state of charge data includes reference voltage data. S200: Adjusting the adjustable resistor according to the reference state of charge data and the state of charge data of the cell unit to adjust the charging and discharging current of the cell unit includes:

[0177] The real-time cell voltage data of the cell unit is obtained based on the voltage of the cell unit.

[0178] Based on the reference voltage data and the real-time cell voltage data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

[0179] In some embodiments, the state of charge (SOC) data includes historical cell voltage drop data, and the reference SOC data includes reference voltage drop data. S200: Adjusting the adjustable resistor based on the reference SOC data and the SOC data of the cell unit to adjust the charging and discharging current of the cell unit includes:

[0180] Historical cell voltage drop data of the cell unit is obtained based on the voltage of the cell unit;

[0181] Based on the reference voltage drop data and the historical cell voltage drop data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

[0182] It should be noted that the current control method for the power battery provided in the embodiments of this application is different from... Figures 1 to 3 The controller in the illustrated device embodiment corresponds to that controller, and will not be described again here to avoid repetition.

[0183] In some implementation scenarios, combined with Figures 1 to 3 The power battery device shown can be applied to electric vehicles for battery charging and discharging management. This device improves cell consistency by differentially charging each individual cell, adjusting the charging strategy, thereby enhancing battery lifespan. An example of the control logic for the controller 300 of this power battery device is as follows:

[0184] A variable resistor 120 is connected in parallel with the cell unit 110 to enable differentiated charging. The variable resistor 120 can adjust the charging and discharging current of the cell unit 110. The reason for the cell differentiation is that due to variations in the manufacturing process (such as the weight difference of the anode and cathode active materials, and the fluctuation of the electrolyte injection volume), each cell unit 110 is actually different, such as in capacity, resistance, and voltage. In the pack, because the position of each cell unit 110 is different, the temperature in the battery varies during use, which further amplifies the differences between cells. As the usage time increases, the consistency between cells further deteriorates.

[0185] In the power battery device, the controller 300 can detect the voltage value of each cell unit 110 in real time, and use the voltage as a basis to determine the state of charge of each cell unit 110. It extracts the voltage change curve after multiple (e.g., 5 times, 10 times, etc., the number of times here is only an example and not a limitation) full charge, calculates the voltage drop of each cell unit 110. When the voltage drop is large, it indicates that the capacity of the cell unit 110 is low and the aging state is serious. Therefore, the resistance value of the adjustable resistor 120 is reduced to reduce the charging and discharging current of the cell unit 110.

[0186] In the discharge state, when the voltage of one cell unit 110 in the power battery device reaches 2.0V, the system will trigger a discharge cutoff signal. At this time, other cells in the power battery device have not reached the lower limit voltage of 2.0V, and some of the charge has not been fully released. Due to the inconsistency of the cells, the capacity is low and the range is reduced. To address this situation, the voltage of each cell unit 110 before and after discharge is detected. For cell units 110 with large voltage difference changes, the adjustable resistor 120 is used to transfer part of the current, thereby reducing the voltage change during the discharge process.

[0187] In some implementation scenarios, the cell unit 110 does not reach the upper or lower limit voltage, and the charging and discharging current is controlled by the voltage drop: such as Figures 5 to 8 As shown, the dark lines have a larger voltage drop and the light lines have a smaller voltage drop. Therefore, the cells with darker lines have a larger current shunt and a smaller charging current to improve cell consistency during cycling. Let the average charging voltage drop of all cells be Base, denoted as x; let the battery module's calibrated capacity be C; let the voltage drop of a single cell be y; and let Cn be the actual capacity of a single cell. The charging current = 1 * Cn. Therefore, when the voltage drop variation of cell unit 110 is greater than the average voltage drop, the actual capacity of cell unit 110 is too low, and the charging and discharging current needs to be reduced. Different methods can be adopted for different battery types, as shown in the following example:

[0188] (1) For lithium iron phosphate (LFP) systems, when the state of charge of cell 110 is in the range of 10-80% SOC, if the voltage drop difference yx is greater than 5mV or y>1.2x, the charging and discharging current is discounted, and the current proportional coefficient k is set, such as Cn=k*C, k can be preset to 0.95; it is adjusted according to historical conditions. If the cell has triggered the voltage drop multiple times in historical operating conditions, resulting in discounting, the value of k is reduced (0.94, 0.93, etc.); conversely (if the voltage drop difference yx is less than -10mV or y<0.8x), the value of k is increased, greater than 1;

[0189] Meanwhile, the resistance value of the adjustable resistor 120 is adjusted in real time at regular intervals, thereby intelligently controlling the charging and discharging current of the cell unit 110 through voltage drop, and reducing the difference in state of charge between the cell units 110.

[0190] When the state of charge (SOC) of cell unit 110 is in the range of <10% SOC or >80% SOC, if the voltage drop difference yx is greater than 10mV or y>1.5x, the charging and discharging current is discounted, such as Cn=k*C, where k can be preset to 0.9. The discount is adjusted according to historical data. If the cell has triggered voltage drop multiple times in historical operating conditions, resulting in discount, the value of k is reduced; conversely, the value of k is increased. Within this SOC range, since the battery voltage is more likely to reach the upper or lower limit, the discount factor k needs to be greater than 10-80% SOC to reduce the risk of excessive voltage drop.

[0191] (2) For the ternary lithium (NCM) system, its voltage-SOC is different from that of the LFP system, and it presents a sloping line. Therefore, when the state of charge of the cell unit 110 is in the range of 3-100% SOC, if the voltage drop difference yx is greater than 12mV or y>1.2x, the charging and discharging current is discounted, such as Cn=k*C, where k can be preset to 0.9; conversely (if the voltage drop difference yx is less than -12mV or y<0.8x), the value of k increases and is greater than 1.

[0192] Exemplarily, during the charging process of the cell unit 110: when the capacity of a single cell reaches 3.8V, charging is terminated, resulting in some cells not being fully charged; therefore, for cells with a voltage higher than the average value, the charging current is reduced; for cells with a voltage lower than the average value, the charging current is increased, so that when the charging is finally terminated, the final voltages of all cells tend to be consistent, and the difference in capacity consistency between the cells is reduced; let the average voltage of each cell during charging be a, the standard deviation of the voltage of each cell be s (calculated after removing scattered points), the charging rate be C, the voltage of a single cell be b, and the charging rate be Cn; when b>a+m*s (m is a coefficient, which can be adjusted according to the cell aging state), Cn=k*C, 0.9<k<1; the value of k is set according to the difference between b and a, the larger the difference, the smaller k; for example, when 3.8-3.42=0.38V, k=0.9; when 3.61-3.42=0.19V, k=0.95; when 3.55-3.42=0.13V, k=0.98; finally, a linear relationship can be established based on the above scattered points to infer the charging derating coefficient under different voltage differences (such as Figure 8 shown);

[0193] Perform charge and discharge derating adjustment for cells with severe aging, and reduce the aging rate between the cell units 110 through derating, so as to reduce the difference;

[0194] The same applies to the discharging process. For batteries with large voltage difference changes, current-limited discharging is performed to reduce the risk of vehicle stalling (the BMS management strategy is to avoid over-discharging of the battery, but when the lower limit voltage drops to 2.0V, a protection mechanism will be triggered to limit the current output, which is manifested as a sudden drop in vehicle power);

[0195] During use, cell aging is affected by many factors, and the aging rates are inconsistent. Therefore, the resistance value of the adjustable resistor will change in real time, and the shunt value is theoretically calculated by combining the data of the first 5 charge and discharge cycles to realize differentiated charging;

[0196] The charge and discharge rate in the calculation logic can be set in advance, and can be adjusted according to the real-time collected data during use.

[0197] In some embodiments, in the power battery device as shown in 1 to Figure 3 , the cell units 110 are in a series state, the voltages are superimposed to achieve a 400 / 800V high-voltage platform, and the charge and discharge current is constant; on the original basis, an adjustable resistor 120 is connected in parallel to the outside of each cell unit 110 as a shunt, and calculations are performed using the capacity, voltage, temperature parameters, etc. collected by the controller 300. When the cell aging state is severe, the resistance value of the adjustable resistor is reduced to shunt part of the current and reduce the charging current; on the contrary, for batteries in excellent condition, the impedance of the adjustable resistor is increased, thereby increasing the charging current of the battery to realize differentiated charging;

[0198] The pack structure of the power battery device: Between two battery cells 110, the positive and negative terminals of multiple single battery cells 110 are connected in sequence by connectors, as shown in the dashed box. A water cooling system (water cooling plate) is set in the middle of the two large surfaces of the battery cells. The height of the water cooling plate is generally lower than the terminal of the battery cell 110. Therefore, an adjustable resistor is set on the top of the water cooling plate to achieve differentiated charging without increasing the pack volume or affecting the space utilization rate of the pack.

[0199] In some embodiments, the working principle of the adjustable resistor 120 can be as follows: the adjustable resistor 120 is composed of two fixed plates and one moving plate. The moving plate can rotate left and right, and its position is controlled and adjusted by the controller 300. The resistance value of the adjustable resistor is adjusted according to the state of charge of the battery cell 110, thereby controlling the charging current of the battery cell 110.

[0200] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0201] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0202] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they 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 portion 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 described in 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.

[0203] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0204] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0205] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A power battery device, characterized in that, Includes multiple battery cell units, voltage detection circuits, and controllers; The plurality of battery cell units are connected in series, each battery cell unit is connected in parallel with an adjustable resistor, and the battery cell unit is connected to the voltage detection circuit, which is used to acquire the voltage of the battery cell unit. The controller is connected to the adjustable resistor and the voltage detection circuit respectively; the controller is used for: The state of charge data of the battery cell is obtained based on the voltage of the battery cell. The adjustable resistor is adjusted based on the reference state of charge data and the state of charge data of the battery cell to regulate the charging and discharging current of the battery cell.

2. The power battery device according to claim 1, characterized in that, The state of charge data includes real-time cell voltage data, the reference state of charge data includes reference voltage data, and the controller is further configured to: The real-time cell voltage data of the cell unit is obtained based on the voltage of the cell unit; Based on the reference voltage data and the real-time cell voltage data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

3. The power battery device according to claim 2, characterized in that, The controller is also used for: The reference voltage data is obtained by averaging the real-time cell voltage data of the multiple cell units. The voltage difference data is obtained by performing difference processing between the reference voltage data and the real-time cell voltage data of the cell unit; The current adjustment data is determined based on the voltage difference data.

4. The power battery device according to claim 3, characterized in that, The current regulation data includes a current proportional coefficient. If the power battery device is in a charging state, the controller is further configured to: If the real-time cell voltage data of the cell unit is greater than the reference voltage data, then the current proportionality coefficient is determined to be less than 1, and the current proportionality coefficient is negatively correlated with the voltage difference data. If the real-time cell voltage data of the cell unit is less than the reference voltage data, then the current proportionality coefficient is determined to be greater than 1, and the current proportionality coefficient is positively correlated with the voltage difference data.

5. The power battery device according to claim 3, characterized in that, The current regulation data includes a current proportional coefficient. If the power battery device is in a discharging state, the controller is further configured to: If the real-time cell voltage data of the cell unit is greater than the reference voltage data, then the current proportionality coefficient is determined to be greater than 1, and the current proportionality coefficient is positively correlated with the voltage difference data. If the real-time cell voltage data of the cell unit is less than the reference voltage data, then the current proportionality coefficient is determined to be less than 1, and the current proportionality coefficient is negatively correlated with the voltage difference data.

6. The power battery device according to claim 3, characterized in that, The controller is also used for: Standard deviation data of voltage is obtained by performing standard deviation processing on the real-time cell voltage data of the multiple cell units. The voltage threshold is determined based on the voltage standard deviation data; If the voltage difference data is greater than the voltage threshold, then the adjustable resistor of the battery cell is adjusted according to the current adjustment data; If the voltage difference data is less than or equal to the voltage threshold, the adjustable resistor of the battery cell will not be adjusted according to the current adjustment data.

7. The power battery device according to claim 1, characterized in that, The state of charge data includes historical cell voltage drop data, the reference state of charge data includes reference voltage drop data, and the controller is further configured to: The historical cell voltage drop data of the cell unit is obtained based on the voltage of the cell unit; Based on the reference voltage drop data and the historical cell voltage drop data of the cell unit, the current adjustment data is determined, and the adjustable resistor is adjusted according to the current adjustment data.

8. The power battery device according to claim 7, characterized in that, The controller is also used for: The baseline voltage drop data is obtained by averaging the historical cell voltage drop data of the multiple cell units. The current regulation data is determined based on the reference voltage drop data and the historical cell voltage drop data of the cell unit.

9. The power battery device according to claim 8, characterized in that, The current regulation data includes a current proportionality coefficient, and the controller is further configured to: Get the preset multiple data; The multiple voltage drop data is determined based on the baseline voltage drop data and the preset multiple data; If the historical cell voltage drop data is greater than the multiple voltage drop data, then the current ratio coefficient is determined to be less than 1, and the current ratio coefficient is negatively correlated with the preset multiple data. If the historical cell voltage drop data is less than the multiple voltage drop data, then the current ratio coefficient is determined to be greater than 1, and the current ratio coefficient is positively correlated with the preset multiple data.

10. The power battery device according to claim 8, characterized in that, The current regulation data includes a current proportionality coefficient, and the controller is further configured to: The voltage drop difference data is obtained by performing difference processing between the reference voltage drop data and the historical cell voltage drop data of the cell unit. If the historical cell voltage drop data is greater than the reference voltage drop data, then the current proportional coefficient is determined to be less than 1, and the voltage drop difference data is negatively correlated with the current proportional coefficient. If the historical cell voltage drop data is less than the reference voltage drop data, then the current proportionality coefficient is determined to be greater than 1, and the voltage drop difference data is positively correlated with the current proportionality coefficient.

11. The power battery device according to claim 1, characterized in that, The state of charge (SOC) data includes real-time cell voltage data and historical cell voltage drop data; the reference SOC data includes reference voltage data and reference voltage drop data; the controller is further configured to: Based on the reference voltage data and the real-time cell voltage data of the cell unit, the first current adjustment data is determined; The second current adjustment data is determined based on the reference voltage drop data and the historical cell voltage drop data of the cell unit; The current adjustment data is determined based on the minimum value between the first current adjustment data and the second current adjustment data, and the adjustable resistor is adjusted based on the current adjustment data.

12. The power battery device according to any one of claims 1 to 11, characterized in that, The battery cell unit also includes an electronic switch, which is connected in series with the adjustable resistor and controls the on / off state of the adjustable resistor through the electronic switch.

13. A current control method for a power battery, characterized in that, The control method, applied to the power battery device according to any one of claims 1 to 12, comprises: The state of charge data of the battery cell is obtained based on the voltage of the battery cell. The adjustable resistor is adjusted based on the reference state of charge data and the state of charge data of the battery cell to regulate the charging and discharging current of the battery cell.

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