Battery equalization control method and device, vehicle controller and storage medium

Abstract

This application provides a battery balancing control method, device, vehicle controller, and storage medium, belonging to the field of automotive technology. The method includes: firstly, calculating the charge difference based on the charge values ​​of each battery in the battery pack; when the charge difference exceeds a preset threshold, further checking the voltage difference between the terminal voltage of the target battery with the highest charge value and the battery pack reference voltage; if the voltage difference also meets preset conditions, dynamically calculating the target balancing current based on the current charge value and performing energy transfer. Because it employs dual criteria of charge and voltage, it avoids relying solely on the charge value as the trigger for balancing control, thus avoiding false triggering due to errors in charge value estimation, enhancing the reliability of balancing control, and thereby ensuring the stability and safety of the battery pack.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a battery equalization control method, device, vehicle controller, and storage medium. Background Technology

[0002] In the electric vehicle field, differences in manufacturing processes and aging levels among the individual cells in a battery pack can lead to inconsistent charge values ​​after long-term operation, affecting the overall performance of the battery pack. Therefore, it is necessary to perform equalization control within the battery pack, transferring energy from high-charged cells to low-charged cells to maintain consistent charge values ​​across all cells. Currently, the decision to activate equalization control is typically based on the charge values ​​of each individual cell.

[0003] However, since the charge value is estimated based on data such as current and voltage, if the charge value deviates from the true value during initialization, or if the current and voltage data are affected by noise during battery operation, the estimated charge value will accumulate errors, leading to false triggering of equalization control and affecting the stability and safety of the battery pack. Summary of the Invention

[0004] This application provides a battery balancing control method, apparatus, vehicle controller, and storage medium to enhance the reliability of battery balancing control upon triggering. The technical solution is as follows: On the one hand, a battery equalization control method is provided, the method comprising: The charge difference of the battery pack is determined based on the charge value of each battery in the battery pack; If the charge difference meets the charge difference condition, the voltage difference corresponding to the terminal voltage of the target battery is determined. The target battery is the battery with the highest charge value in the battery pack, and the voltage difference is the degree of difference between the terminal voltage of the target battery and the reference voltage in the battery pack. If the voltage difference meets the voltage difference condition, the target battery is controlled to output a target equalization current based on the charge value of each battery. The target equalization current is used to perform equalization control in the battery pack.

[0005] In some embodiments, determining the charge difference of the battery pack based on the charge value of each battery in the battery pack includes: Determine the maximum and minimum charge values ​​of each cell in the battery pack; The charge difference of the battery pack is determined based on the relationship between the charge difference and the charge difference threshold. The charge difference is the difference between the maximum charge value and the minimum charge value, and the charge difference threshold is a preset charge difference critical value.

[0006] In some embodiments, the charge difference satisfies the charge difference condition, including: The charge difference is greater than the charge difference threshold.

[0007] In some embodiments, determining the voltage difference corresponding to the terminal voltage of the target battery includes: Determine the average voltage value in the battery pack; Based on the relationship between the terminal voltage of the target battery and the average voltage value, the voltage difference of the terminal voltage of the target battery in the battery pack is determined.

[0008] In some embodiments, the voltage difference satisfies a voltage difference condition, including: The terminal voltage of the target battery is greater than the average voltage value, and the difference between the terminal voltage of the target battery and the average voltage value is greater than the voltage difference threshold, which is a preset voltage difference critical value.

[0009] In some embodiments, controlling the target battery to output a target equalization current based on the charge value of each battery includes: Determine the average charge value of each battery in the battery pack, and determine the target charge difference value corresponding to the target battery. The target charge difference value is the difference between the charge value of the target battery and the average charge value. The target charge difference and the average charge value are input into the fuzzy controller, and the fuzzy controller controls the target battery to output the target equalization current.

[0010] In some embodiments, controlling the target battery to output a target equalization current via the fuzzy controller includes: Based on the knowledge base corresponding to the fuzzy controller, the fuzzy quantity corresponding to the target charge difference is determined as the first fuzzy quantity, and the fuzzy quantity corresponding to the average charge value is determined as the second fuzzy quantity. The knowledge base includes the rule base and membership function corresponding to the fuzzy controller. The rule base contains multiple fuzzy rules represented by linguistic variables, and each fuzzy quantity is a fuzzy subset that maps the corresponding value through the membership function. Based on the first fuzzy quantity and the second fuzzy quantity, a target fuzzy rule is matched in each fuzzy rule to determine the current fuzzy quantity corresponding to the target fuzzy rule. The current fuzzy quantity is a fuzzy subset of the balanced current represented by linguistic variables in the target fuzzy rule. The target battery outputs a target equalization current based on the current fuzzy value.

[0011] In some embodiments, the control logic of the fuzzy rule includes: The equalization current is positively correlated with the target charge difference; And / or, when the average charge value is greater than a preset charge threshold, the equalization current is less than a preset current value, where the preset charge threshold is a high-level critical value for the battery pack under the state of charge.

[0012] On the other hand, a battery equalization control device is provided, the device comprising: The charge difference determination unit is configured to determine the charge difference of the battery pack based on the charge value of each battery in the battery pack; The voltage difference determination unit is configured to determine the voltage difference corresponding to the terminal voltage of the target battery if the charge difference meets the charge difference condition. The target battery is the battery with the highest charge value in the battery pack, and the voltage difference is the degree of difference between the terminal voltage of the target battery and the reference voltage in the battery pack. The equalization control unit is configured to control the target battery to output a target equalization current based on the charge value of each battery if the voltage difference meets the voltage difference condition, and the target equalization current is used to perform equalization control in the battery pack.

[0013] In another direction, a vehicle controller is provided, which includes a main control module, a processor, and a memory. The memory is used to store at least one computer program, which is loaded and executed by the processor to implement the battery equalization control method in the embodiments of this application.

[0014] On the other hand, a computer-readable storage medium is provided for storing at least one computer program, which is loaded and executed by a processor to implement the battery equalization control method in the embodiments of this application.

[0015] On the other hand, a computer program product is provided, including a computer program that is executed by a processor to implement the battery equalization control method in the embodiments of this application.

[0016] This application provides a battery equalization control method. First, the charge difference is calculated based on the charge values ​​of each battery in the battery pack. When the charge difference exceeds a preset threshold, the voltage difference between the terminal voltage of the target battery with the highest charge value and the reference voltage of the battery pack is further checked. If the voltage difference also meets preset conditions, the target equalization current is dynamically calculated based on the current charge value, and energy transfer is performed. Because both charge and voltage are used as criteria, relying solely on the charge value as the trigger for equalization control avoids false triggering due to estimation errors in the charge value, enhancing the reliability of equalization control and thus ensuring the stability and safety of the battery pack. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the implementation environment of a battery equalization control method provided in an embodiment of this application; Figure 2 This is an active balancing topology based on inductors provided according to an embodiment of this application; Figure 3 This is a flowchart of a battery equalization control method according to an embodiment of this application; Figure 4 This is a flowchart of another battery equalization control method provided according to an embodiment of this application; Figure 5 This is a flowchart illustrating the overall implementation of a battery equalization control method according to an embodiment of this application. Figure 6 This is a fuzzy control principle diagram provided according to an embodiment of this application; Figure 7 This is a block diagram of a battery equalization control device according to an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a vehicle controller provided according to an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0020] In this application, the terms "first", "second", etc. are used to distinguish identical or similar items with essentially the same function. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor is there any limitation on the quantity or execution order.

[0021] In this application, the term "at least one" means one or more, and "multiple" means two or more.

[0022] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0023] Figure 1 This is a schematic diagram illustrating the implementation environment of a battery equalization control method according to an embodiment of this application. See also... Figure 1 The implementation environment includes vehicle 101, network 102, and server 103. Network 102 serves as the medium for providing a communication link between vehicle 101 and server 103. Network 102 may include various types of wireless communication links, such as Bluetooth communication links, Wireless-Fidelity (Wi-Fi) communication links, or microwave communication links.

[0024] In some embodiments, vehicle 101 is a new energy vehicle, such as a pure electric vehicle, a plug-in hybrid electric vehicle, or a fuel cell electric vehicle. Vehicle 101 is equipped with a vehicle controller, an on-board charger, a power battery pack, and a battery management system for managing the power battery pack. The power battery pack consists of multiple individual cells connected in series or parallel, providing electrical energy to the vehicle controller and vehicle loads. The vehicle controller can communicate with the on-board terminal, power battery pack, battery management system, and on-board charger via a CAN (Controller Area Network) bus. The vehicle controller can also communicate with the user terminal via a wireless network. Accordingly, the vehicle controller can collect real-time state parameters such as voltage, current, and temperature of each individual cell in the power battery pack via the CAN bus, and calculate the charge value of each individual cell, uploading the collected battery state data to server 103 via network 102.

[0025] Figure 2 This is an active balancing topology diagram based on inductance provided according to an embodiment of this application, illustrating the energy transfer mechanism between individual cells (Cell1, Cell2, Cell3) in a battery pack. For example... Figure 2 As shown, this circuit achieves bidirectional energy flow between batteries by controlling the interaction of four switches (S1-S4) and two inductors (L1, L2). Taking the middle cell Cell2 and the right-side cell Cell1 as an example, when balancing is required, the complementary conduction of switches S1 and S2 is controlled, and inductor L1 is used as an energy storage element to construct a charging and discharging circuit: during the charging phase, current flows through inductor L1 to store magnetic field energy; during the discharging phase, inductor L1 releases energy to transfer charge to the battery. Similarly, Cell2 and the left-side cell Cell3 form another independent balancing circuit through inductor L2 and switches S3 and S4.

[0026] Figure 3 This is a flowchart of a battery balancing control method according to an embodiment of this application. The method is executed by the vehicle's overall controller. Figure 3As shown, the battery balancing control method includes the following steps: 301. Determine the charge difference of the battery pack based on the charge value of each battery in the battery pack.

[0027] In this embodiment, to improve the accuracy and reliability of the battery pack active balancing control, a rigorous dual-verification startup mechanism is first constructed. Specifically, during vehicle operation or charging, the vehicle controller collects key parameters such as voltage, current, and temperature of each battery in the battery pack in real time, and accurately estimates the charge value of each battery based on these parameters. Subsequently, the controller performs statistical analysis and calculation on the charge values ​​of the entire battery pack, filters out the maximum and minimum values, and calculates the absolute difference between them, thereby obtaining the charge difference that can objectively characterize the overall inconsistency of the battery pack. When this difference value meets the charge difference condition, it means that the energy distribution inside the battery pack has shifted significantly, and intervention is necessary. At this time, the vehicle controller does not immediately start balancing control, but generates a primary balancing enable signal and automatically enters the next voltage verification process. It should be noted that the charge difference condition refers to the degree of difference in the battery pack's state of charge, such as the difference between the highest and lowest charge values ​​in the battery pack.

[0028] 302. If the charge difference meets the charge difference condition, determine the voltage difference corresponding to the terminal voltage of the target battery. The target battery is the battery with the highest charge value in the battery pack, and the voltage difference is the degree of difference between the terminal voltage of the target battery and the voltage state of the battery pack.

[0029] In this embodiment, when the charge difference is determined to meet the charge difference condition, to further eliminate the risk of misjudgment caused by sensor noise, instantaneous voltage spikes, etc., the battery with the highest charge value in the current battery pack is further locked as the target battery. The vehicle controller reads the terminal voltage of the target battery in real time and compares it with the overall voltage state of the battery pack (e.g., average voltage) to determine the voltage difference corresponding to the terminal voltage of the target battery. Only when the voltage difference also meets the voltage difference condition (e.g., the terminal voltage is significantly higher than the average voltage and the difference exceeds a certain threshold) will the vehicle controller finally confirm the triggering of the equalization operation, thereby avoiding the problem of false triggering caused by relying solely on the charge value as the triggering basis. This dual criterion mechanism based on the state of charge and terminal voltage performance effectively combines the characteristics of the charge value reflecting the long-term energy distribution state and the voltage reflecting the instantaneous electrical state, improving the anti-interference capability and decision accuracy of the control system under complex operating conditions.

[0030] 303. If the voltage difference meets the voltage difference condition, the target battery outputs a target equalization current based on the charge value of each battery. The target equalization current is used to perform equalization control in the battery pack.

[0031] In this embodiment, after confirming that the dual triggering conditions are met and the equalization control is officially initiated, the traditional crude mode of using fixed thresholds or fixed currents is abandoned, and a more intelligent and adaptive dynamic adjustment method is adopted instead. Specifically, the vehicle controller inputs the real-time state of charge information of the current battery pack (such as the overall average charge level and the degree of deviation of individual cells) as key input variables into the fuzzy controller. This fuzzy controller can simulate the decision-making thinking of human experts and make comprehensive judgments based on a complex logical rule base preset inside. The fuzzy controller calculates an optimal target equalization current in real time based on the severity of battery inconsistency and the current overall energy level of the battery pack. For example, when a severe inconsistency is detected but the overall battery pack charge is high, the fuzzy controller will automatically control the target battery to output a moderate or limited current to prevent overcharging risks during the process of eliminating differences; conversely, if the overall charge is sufficient and the differences are significant, a larger equalization current will be output to improve equalization efficiency. Ultimately, the active balancing circuit (such as an inductor-based bidirectional DC-DC converter) precisely performs energy transfer and redistribution based on this dynamically generated target balancing current until the battery pack's consistency is restored to the ideal range.

[0032] This application provides a battery equalization control method. First, the charge difference is calculated based on the charge values ​​of each battery in the battery pack. When the charge difference exceeds a preset threshold, the voltage difference between the terminal voltage of the target battery with the highest charge value and the reference voltage of the battery pack is further checked. If the voltage difference also meets preset conditions, the target equalization current is dynamically calculated based on the current charge value, and energy transfer is performed. Because both charge and voltage are used as criteria, relying solely on the charge value as the trigger for equalization control avoids false triggering due to estimation errors in the charge value, enhancing the reliability of equalization control and thus ensuring the stability and safety of the battery pack.

[0033] Figure 4 This is a flowchart of another battery balancing control method provided according to an embodiment of this application. This method is executed by the vehicle's overall controller. Figure 4 As shown, the battery balancing control method includes the following steps: 401. Determine the maximum and minimum charge values ​​of each cell in the battery pack; based on the relationship between the charge difference and the charge difference threshold, determine the charge difference of the battery pack, where the charge difference is the difference between the maximum and minimum charge values, and the charge difference threshold is a preset charge difference critical value.

[0034] In the embodiments of this application, Figure 5This is a flowchart illustrating the overall implementation of a battery balancing control method according to an embodiment of this application. Figure 5 As shown, the entire control process begins with the "data acquisition and SOC estimation" stage. The vehicle controller acquires key state information such as voltage, current, and temperature of each battery in the battery pack in real time, and estimates the current state of charge (SOC) of each battery based on this multi-dimensional physical information using a preset algorithm. Subsequently, the vehicle controller performs statistical processing and calculations on the SOC of the entire battery pack, specifically including: traversing and determining the maximum SOC (SOC_max) and minimum SOC (SOC_min) among all batteries in the battery pack, and calculating the absolute difference between the two, i.e., the SOC difference (SOC_max - SOC_min). This SOC difference can intuitively reflect the uneven energy distribution within the battery pack, which is the SOC difference that measures the degree of difference in the state of charge of the battery pack.

[0035] 402. If the charge difference is greater than the charge difference threshold, determine the average voltage value in the battery pack; based on the relationship between the terminal voltage of the target battery and the average voltage value, determine the voltage difference of the terminal voltage of the target battery in the battery pack.

[0036] In this embodiment, the vehicle controller compares the calculated charge difference with a preset charge difference threshold (△SOC_th) within the system. If the charge difference is greater than the charge difference threshold, it is determined that the charge difference of the current battery pack meets the charge difference condition, and a primary equalization enable signal is generated, and the system automatically enters the voltage verification stage.

[0037] In some embodiments, the vehicle controller first calculates the average voltage value (V_avg) of all batteries in the battery pack and uses it as the core benchmark for measuring the overall voltage state of the battery pack. Then, it locks the battery with the highest charge value as the target battery, reads its terminal voltage (v_cell_high) in real time, and analyzes the numerical relationship and deviation between this terminal voltage and the aforementioned average voltage value to determine the voltage difference of the target battery's terminal voltage in the battery pack.

[0038] 403. If the terminal voltage of the target battery is greater than the average voltage value, and the difference between the terminal voltage of the target battery and the average voltage value is greater than the voltage difference threshold, the voltage difference threshold is a preset voltage difference critical value. Determine the average charge value of each battery in the battery pack, and determine the target charge difference value corresponding to the target battery. The target charge difference value is the difference between the charge value of the target battery and the average charge value.

[0039] In this embodiment, the vehicle controller determines whether the terminal voltage of the target battery is higher than the average voltage value, and whether the difference between the two (v_cell_high-V_avg) exceeds a preset voltage difference threshold (ΔV_th). Only when both conditions are met simultaneously, i.e., it is confirmed that the target battery is not only at a high state of charge, but also significantly higher than the average level in the group in terms of voltage performance, will the start-up equalization be finally confirmed, thereby effectively avoiding malfunctions caused by instantaneous voltage fluctuations or SOC estimation errors.

[0040] In some embodiments, such as Figure 5 As shown, once the target battery meets the equalization triggering conditions, the control input is first calculated and extracted. The vehicle controller not only calculates the average charge value (SOC_avg) of all individual cells in the battery pack to characterize the current overall charge level of the battery pack, but also calculates the difference between the target battery's charge value and this average charge value, i.e., the target charge difference (SOC_diff). This difference accurately reflects the degree of charge deviation of the target battery relative to the overall level of the battery pack.

[0041] 404. Input the target charge difference and average charge value into the fuzzy controller, and control the target battery to output the target equalization current through the fuzzy controller.

[0042] In this embodiment, the target charge difference and average charge value calculated above are used as two key input variables and simultaneously input into the fuzzy controller. The fuzzy controller performs fuzzy processing and comprehensive reasoning on these two input quantities according to preset fuzzy rules, thereby dynamically determining an optimal target equilibrium current.

[0043] In some embodiments, Figure 6 This is a fuzzy control principle diagram provided according to an embodiment of this application, such as... Figure 6 As shown, the process of inputting the target charge difference and average charge value into the fuzzy controller, and then controlling the target battery to output the target equalization current, is essentially a control flow that simulates human expert decision-making. This process begins with the "fuzzification" stage, which calls upon the fuzzy controller's pre-built knowledge base. This knowledge base stores membership functions set for different operating conditions. Through these membership functions, the numerical input quantities—the aforementioned target charge difference and average charge value—can be transformed into fuzzy quantities with linguistic variable characteristics. Specifically, the target charge difference is mapped to a first fuzzy quantity (such as "large," "medium," "small," etc.), and the average charge value is mapped to a second fuzzy quantity (such as "high," "medium," "low," etc.). These two fuzzy quantities represent fuzzy subsets of the degree of battery inconsistency and fuzzy subsets of the overall battery pack charge level, respectively, thus completing the conversion from precise numerical values ​​to fuzzy concepts.

[0044] Further, the process moves to the "fuzzy reasoning" stage. In this stage, the fuzzy controller performs logical matching based on a rule base contained in the knowledge base. The rule base contains multiple pre-defined control rules expressed in the form of "if...then...", which describe the nonlinear relationship between input and output quantities in the form of linguistic variables. The fuzzy controller uses the calculated first and second fuzzy quantities as preconditions to search and match applicable target fuzzy rules in the rule base. For example, when the rule base detects a fuzzy combination of "high inconsistency" and "moderate overall battery level," it infers that a "larger balancing current" needs to be output. Through this rule-based reasoning, a current fuzzy quantity appropriate to the current battery state is determined. This current fuzzy quantity is the fuzzy subset of the balancing current expressed as linguistic variables, representing the initial control command under specific fuzzy logic.

[0045] In some embodiments, a "defuzzification" operation is performed to convert the inferred fuzzy instructions into hardware-executable physical quantities. The defuzzification module calculates a precise value, the target equalization current, based on the current fuzziness using a specific defuzzification algorithm (such as the centroid method, maximum membership method, etc.). This target equalization current is then sent to the control object (i.e., the equalization circuit) to drive the target battery to perform the corresponding energy transfer operation.

[0046] In some embodiments, the rule base within the fuzzy controller is not a simple linear mapping, but rather embeds physical constraints based on the battery's electrochemical characteristics. This control logic first establishes a positive correlation between the target charge difference and the equalization current. For example, when the average charge value is high, the fuzzy controller tends to control the target battery to output a smaller equalization current to prevent it from prematurely reaching the overcharge protection voltage; conversely, when the average charge value is low, the fuzzy controller allows the target battery to output a larger equalization current to accelerate the equalization process. This design ensures that even when battery pack consistency is severely degraded, it can output strong equalization power, quickly eliminating significant inconsistencies, thereby shortening the equalization time and improving charging efficiency.

[0047] In some embodiments, the polarization effect of the battery is significantly enhanced at the end of the charging process, and the terminal voltage is extremely sensitive to the current response. If a large current balance is maintained at this time, the terminal voltage of the target battery can easily exceed the overcharge protection voltage instantaneously. Based on this, a simple positive correlation may cause safety hazards when the battery pack is in a high energy state. Therefore, the method of this application further introduces a dynamic adjustment mechanism of the average charge value as the second dimension of the control logic. When the average charge value of the battery pack climbs to a preset high threshold value (the high SOC range at the end of the charging process, such as SOC>90%), fuzzy rules will forcibly intervene in the output stage of the equalization current. At this time, even if the target charge difference is still large, the controller will automatically limit the target equalization current to below the preset safe current value according to the principle of "safety first".

[0048] In some embodiments, such as Figure 5 As shown, after the target equalization current is determined by the fuzzy controller, the process immediately enters the equalization execution and dynamic monitoring stage. Specifically, the active equalization circuit is turned on, and the calculated target equalization current is used as the command value to drive the target battery to perform an energy transfer operation, transferring excess energy in the target battery to the battery pack bus or other batteries with low state of charge.

[0049] In some embodiments, throughout the equalization process, real-time closed-loop monitoring of the battery pack state is maintained, continuously collecting voltage and current information of each battery in the pack, and updating the average charge value of each battery and the target charge difference corresponding to the target battery in real time. The fuzzy controller dynamically adjusts the output target equalization current based on these real-time feedback state parameters. For example, as equalization progresses, if the target charge difference is detected to gradually decrease, the controller automatically reduces the amplitude of the target equalization current to smoothly transition the equalization process and prevent over-equalization.

[0050] Furthermore, when the target charge difference corresponding to the target battery has dropped below the preset stop threshold, or the voltage difference between the terminal voltage of the target battery and the average voltage of the battery pack has been sufficiently reduced to meet the equalization stop condition, the active equalization circuit will be turned off to stop the equalization operation for the target battery. However, the end of a single equalization operation does not mean the end of the entire battery pack equalization process. After the current target battery is equalized, the vehicle controller will immediately perform a comprehensive scan and judgment of the state of all batteries in the battery pack, recalculate the charge difference of the entire pack, and identify whether there are other battery cells with abnormally high charge values. If other seriously inconsistent batteries are found in the battery pack (i.e., there are new target batteries that meet the aforementioned charge difference and voltage difference conditions), the system will automatically jump back to the starting step of the equalization control logic, recalculate the target charge difference and average charge value for the newly identified target batteries, and generate a new target equalization current through the fuzzy controller to perform equalization. This process repeats until the vehicle controller determines that the state of charge of all batteries in the battery pack has reached the preset equalization standard, that is, the charge difference of all batteries is within the allowable range. Only then will the equalization control process be finally closed, thereby ensuring the overall consistency and safety of the battery pack.

[0051] In some embodiments, to more intuitively illustrate the specific performance of the method of this application embodiment in practical applications, a set of typical simulation data is used to illustrate the battery equalization control logic of this application. Assume that under a specific vehicle operating condition, the vehicle controller obtains the real-time status of each battery in the battery pack through data acquisition and charge value estimation, identifying the maximum charge value in the battery pack as 0.95 and the minimum charge value as 0.82, and calculating the charge difference as 0.13. Since this charge difference is significantly greater than the preset charge difference threshold (e.g., set to 0.05), it is determined that the consistency of the battery pack has deviated from the normal range. A primary equalization enable signal is then generated, and the subsequent voltage verification process is automatically triggered to ensure the necessity and accuracy of the equalization operation.

[0052] In some embodiments, after entering the voltage verification stage, the average voltage of the battery pack is further calculated to be 3.70V. For the target battery with the highest charge value, its terminal voltage is read as 3.75V. Comparative analysis shows that the terminal voltage of this target battery is not only higher than the average voltage, but the voltage difference between the two reaches 0.05V, which also exceeds the preset voltage difference threshold (e.g., set to 0.03V). Based on this, it is confirmed that the target battery simultaneously meets the dual triggering conditions of "high SOC difference" and "high voltage difference," eliminating the possibility of misjudgment due to instantaneous voltage fluctuations, and finally determining to initiate active balancing control.

[0053] In some embodiments, after determining to initiate equalization control, fuzzification is first performed. The calculated target charge difference value of 0.13 is input into the membership function to determine that it belongs to the "large" fuzzy subset; simultaneously, the current average charge value of the battery pack of 0.88 is input into the membership function to determine that it belongs to the "high" fuzzy subset. Subsequently, the fuzzy controller performs inference based on the built-in rule base and matches the corresponding control rule: "If the target charge difference value is large and the average charge value is high, then the target equalization current is medium." This rule reflects the safety control logic of this scheme: although the inconsistency between batteries is relatively serious, and a large current should be used for rapid equalization, since the battery pack as a whole is in a high-charge state (close to full charge), in order to prevent the target battery voltage from reaching the overcharge protection voltage too quickly, the fuzzy controller adopts a compromise strategy and outputs a medium-intensity equalization current.

[0054] In some embodiments, the "moderate" ambiguity derived from the above reasoning is transformed into precise control commands through a deambiguation operation (such as using the centroid method), for example, outputting a target equalization current of 1.2A. The vehicle controller then controls the active equalization circuit (such as a bidirectional DC-DC converter) to turn on, transferring energy from the target battery with an adjustment current of 1.2A.

[0055] This application provides a battery equalization control method. First, the charge difference is calculated based on the charge values ​​of each battery in the battery pack. When the charge difference exceeds a preset threshold, the voltage difference between the terminal voltage of the target battery with the highest charge value and the reference voltage of the battery pack is further checked. If the voltage difference also meets preset conditions, the target equalization current is dynamically calculated based on the current charge value, and energy transfer is performed. Because both charge and voltage are used as criteria, relying solely on the charge value as the trigger for equalization control avoids false triggering due to estimation errors in the charge value, enhancing the reliability of equalization control and thus ensuring the stability and safety of the battery pack.

[0056] Figure 7 This is a block diagram of a battery balancing control device according to an embodiment of this application. The device is used to execute the steps of the battery balancing control method described above, see [link to relevant documentation]. Figure 7 The device includes: The charge difference determination unit 701 is configured to determine the charge difference of the battery pack based on the charge value of each battery in the battery pack. The voltage difference judgment unit 702 is configured to determine the voltage difference corresponding to the terminal voltage of the target battery if the charge difference meets the charge difference condition. The target battery is the battery with the highest charge value in the battery pack, and the voltage difference is the degree of difference between the terminal voltage of the target battery and the reference voltage in the battery pack. The equalization control unit 703 is configured to control the target battery to output a target equalization current based on the charge value of each battery if the voltage difference meets the voltage difference condition. The target equalization current is used to perform equalization control in the battery pack.

[0057] In some embodiments, the charge difference determination unit is configured to determine the maximum and minimum charge values ​​of each cell in the battery pack; and to determine the charge difference of the battery pack based on the relationship between the charge difference and the charge difference threshold, wherein the charge difference is the difference between the maximum and minimum charge values, and the charge difference threshold is a preset charge difference threshold.

[0058] In some embodiments, the voltage difference determination unit is configured such that the charge difference is greater than the charge difference threshold.

[0059] In some embodiments, the voltage difference determination unit is configured to determine the average voltage value in the battery pack; and to determine the voltage difference of the target battery's terminal voltage in the battery pack based on the relationship between the target battery's terminal voltage and the average voltage value.

[0060] In some embodiments, the equalization control unit is configured such that the terminal voltage of the target battery is greater than the average voltage value, and the difference between the terminal voltage of the target battery and the average voltage value is greater than a voltage difference threshold, wherein the voltage difference threshold is a preset voltage difference critical value.

[0061] In some embodiments, the equalization control unit is configured to determine the average charge value of each battery in the battery pack, determine the target charge difference value corresponding to the target battery, the target charge difference value being the difference between the charge value of the target battery and the average charge value; input the target charge difference value and the average charge value into a fuzzy controller, and control the target battery to output a target equalization current through the fuzzy controller.

[0062] In some embodiments, the equalization control unit is configured to determine, based on the knowledge base corresponding to the fuzzy controller, a first fuzzy quantity corresponding to the target charge difference and a second fuzzy quantity corresponding to the average charge value. The knowledge base includes a rule base and membership functions corresponding to the fuzzy controller. The rule base contains multiple fuzzy rules represented by linguistic variables, and each fuzzy quantity is a fuzzy subset that maps the corresponding value through the membership function. Based on the first and second fuzzy quantities, a target fuzzy rule is matched among the fuzzy rules to determine the current fuzzy quantity corresponding to the target fuzzy rule. The current fuzzy quantity is a fuzzy subset of the equalization current represented by linguistic variables in the target fuzzy rule. The target battery outputs a target equalization current based on the current fuzzy quantity.

[0063] In some embodiments, the control logic of the fuzzy rule includes: the equalization current is positively correlated with the target charge difference; and / or, when the average charge value is greater than a preset charge threshold, the equalization current is less than a preset current value, and the preset charge threshold is a high-level critical value of the battery pack under the state of charge.

[0064] This application provides a battery equalization control device. First, it calculates the charge difference based on the charge values ​​of each battery in the battery pack. When the charge difference exceeds a preset threshold, it further checks the voltage difference between the terminal voltage of the target battery with the highest charge value and the battery pack reference voltage. If the voltage difference also meets preset conditions, it dynamically calculates the target equalization current based on the current charge value and performs energy transfer. By employing both charge and voltage criteria, it avoids relying solely on the charge value as the trigger for equalization control, thus preventing false triggering due to estimation errors in the charge value. This enhances the reliability of equalization control and ensures the stability and safety of the battery pack.

[0065] It should be noted that the battery balancing control device provided in the above embodiments is only illustrated by the division of the above functional modules when running the application. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the battery balancing control device and the battery balancing control method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0066] Figure 8 This is a schematic diagram of the structure of a vehicle controller provided according to an embodiment of this application.

[0067] Typically, the vehicle controller 800 includes: a main control module 801, a CAN interface 802, a hard-wired input interface 803, and a hard-wired output interface 804. The main control module 801 is connected to the CAN interface 802, the hard-wired input interface 803, and the hard-wired output interface 804, respectively.

[0068] The main control module 801 typically includes a processor and memory. The processor may include one or more processing cores, such as a 4-core processor or an 8-core processor. The processor can be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the vehicle's display screen. In some embodiments, the processor may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning. The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, a non-transitory computer-readable storage medium in the memory is used to store at least one computer program, which is executed by a processor to implement the battery equalization control method provided in the method embodiments of this application.

[0069] The CAN interface 802 may include a powertrain CAN interface, a motor CAN interface, and a diagnostic CAN interface. The powertrain CAN interface is used to communicate with the vehicle's powertrain module, the motor CAN interface is used to communicate with the vehicle's motor controller, and the diagnostic CAN interface is used to communicate with diagnostic equipment.

[0070] The hard-wired input interface 803 is used to receive hard-wired control signals. The hard-wired output interface 804 is used to send control commands to the vehicle's electronic control components, causing them to perform corresponding actions. These electronic control components include a power management system, a motor controller, an on-board charger, and a body control system.

[0071] The main control module 801 can communicate with the vehicle's powertrain module, motor controller, and diagnostic equipment via the CAN interface 802, and generate control commands based on the hard-wired control signals received by the hard-wired input interface 803, so as to send the control commands to the vehicle's electronic control components via the hard-wired output interface 804.

[0072] Those skilled in the art will understand that Figure 8 The structure shown does not constitute a limitation on the vehicle controller 800, and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0073] This application also provides a computer-readable storage medium storing at least one computer program. This computer program is loaded and executed by a processor of an electronic device to implement the operations performed by the electronic device in the battery equalization control method of the above embodiments. For example, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0074] This application also provides a computer program product, including a computer program loaded and executed by a processor to implement the battery equalization control method as described in the above embodiments.

[0075] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0076] The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery equalization control method, characterized in that, The method includes: The charge difference of the battery pack is determined based on the charge value of each battery in the battery pack; If the charge difference meets the charge difference condition, the voltage difference corresponding to the terminal voltage of the target battery is determined. The target battery is the battery with the highest charge value in the battery pack, and the voltage difference is the degree of difference between the terminal voltage of the target battery and the reference voltage in the battery pack. If the voltage difference meets the voltage difference condition, the target battery is controlled to output a target equalization current based on the charge value of each battery. The target equalization current is used to perform equalization control in the battery pack.

2. The method of claim 1, wherein, Determining the charge difference of the battery pack based on the charge value of each cell in the battery pack includes: Determine the maximum and minimum charge values ​​of each cell in the battery pack; The charge difference of the battery pack is determined based on the relationship between the charge difference and the charge difference threshold. The charge difference is the difference between the maximum charge value and the minimum charge value, and the charge difference threshold is a preset charge difference critical value.

3. The method of claim 2, wherein, The charge difference satisfies the charge difference condition, including: The charge difference is greater than the charge difference threshold.

4. The method of claim 1, wherein, The determination of the voltage difference corresponding to the terminal voltage of the target battery includes: Determine the average voltage value in the battery pack; Based on the relationship between the terminal voltage of the target battery and the average voltage value, the voltage difference of the terminal voltage of the target battery in the battery pack is determined.

5. The method of claim 4, wherein, The voltage difference satisfies the voltage difference condition, including: The terminal voltage of the target battery is greater than the average voltage value, and the difference between the terminal voltage of the target battery and the average voltage value is greater than the voltage difference threshold, which is a preset voltage difference critical value.

6. The method of claim 1, wherein, The step of controlling the target battery to output a target equalization current based on the charge value of each battery includes: Determine the average charge value of each battery in the battery pack, and determine the target charge difference value corresponding to the target battery. The target charge difference value is the difference between the charge value of the target battery and the average charge value. The target charge difference and the average charge value are input into the fuzzy controller, and the fuzzy controller controls the target battery to output the target equalization current.

7. The method of claim 6, wherein, The step of controlling the target battery to output a target equalization current through the fuzzy controller includes: Based on the knowledge base corresponding to the fuzzy controller, the fuzzy quantity corresponding to the target charge difference is determined as the first fuzzy quantity, and the fuzzy quantity corresponding to the average charge value is determined as the second fuzzy quantity. The knowledge base includes the rule base and membership function corresponding to the fuzzy controller. The rule base contains multiple fuzzy rules represented by linguistic variables, and each fuzzy quantity is a fuzzy subset that maps the corresponding value through the membership function. Based on the first fuzzy quantity and the second fuzzy quantity, a target fuzzy rule is matched in each fuzzy rule to determine the current fuzzy quantity corresponding to the target fuzzy rule. The current fuzzy quantity is a fuzzy subset of the balanced current represented by linguistic variables in the target fuzzy rule. The target battery outputs a target equalization current based on the current fuzzy value.

8. The method of claim 6, wherein, The control logic of the fuzzy rule includes: The equalization current is positively correlated with the target charge difference; And / or, when the average charge value is greater than a preset charge threshold, the equalization current is less than a preset current value, where the preset charge threshold is a high-level critical value for the battery pack under the state of charge.

9. A balancing control device of a battery, characterized by comprising: The device includes: The charge difference determination unit is configured to determine the charge difference of the battery pack based on the charge value of each battery in the battery pack; The voltage difference determination unit is configured to determine the voltage difference corresponding to the terminal voltage of the target battery if the charge difference meets a preset charge difference condition. The target battery is the battery with the highest charge value in the battery pack, and the voltage difference is the degree of difference between the terminal voltage of the target battery and the reference voltage in the battery pack. The equalization control unit is configured to control the target battery to output a target equalization current based on the charge value of each battery if the voltage difference meets a preset voltage difference condition. The target equalization current is used to perform equalization control in the battery pack.

10. A vehicle control unit, characterized by, The vehicle controller includes a main control module, which includes a processor and a memory. The memory is used to store at least one computer program, which is loaded and executed by the processor to perform the battery equalization control method according to any one of claims 1 to 8.

11. A computer readable storage medium, characterized in that, The computer-readable storage medium is used to store at least one computer program for executing the battery equalization control method according to any one of claims 1 to 8.

12. A computer program product comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the battery equalization control method as described in any one of claims 1 to 8.

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