Method for soc estimation control of high-low voltage dual battery pack in multiple working conditions and related equipment thereof

Abstract

The application provides a high-low voltage double battery pack multi-working condition SOC estimation control method and related equipment, relates to the power battery management technical field of new energy vehicles, and solves the inaccurate estimation problem of multiple working conditions by independently estimating the original SOC of the double battery pack, accurately identifying the working mode, and matching the corresponding calculation rules. In the parallel, pressure difference degradation and series fast charging mode, the capacity is converted based on the minimum value and range of the two pack SOCs, the real available power is accurately represented, and the SOC is prevented from being too high or too low, and the power is prevented from being limited or the gun is prevented from being jumped; in the fault isolation single pack mode, the original SOC value of the fault-free pack is directly used as the system SOC, the power display is ensured to be real and reliable during emergency driving, the driver is helped to accurately judge the endurance, and the vehicle operation safety and the battery capacity utilization are comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of power battery management technology for new energy vehicles, and in particular to a method for SOC estimation and control of high and low voltage dual battery packs under multiple operating conditions, and related equipment. Background Technology

[0002] Currently, most high-low voltage switching vehicles adopt a dual-battery pack architecture, which achieves high-voltage fast charging through series connection and can switch to parallel output during driving discharge and slow charging. At the same time, the vehicle supports single-pack fault isolation, single-pack emergency driving and single-pack independent charging. However, existing SOC estimation schemes are typically designed only for single battery packs, failing to differentiate between parallel, series, and independent SOC correction logics for dual-pack operation. This results in significant discrepancies between the displayed SOC and the actual usable capacity when the voltage difference between the two packs is large. When one battery pack malfunctions and locks out, the system does not switch the SOC display logic separately, still using the dual-pack balancing formula for calculation. This leads to an inflated or inflated SOC on the instrument panel, severely impacting the driver's judgment of the remaining driving range. Furthermore, parallel charging and discharging of dual packs does not perform capacity conversion based on the SOC difference between the two packs, failing to accurately represent the system's true remaining usable capacity. This can easily lead to problems such as premature power limiting or premature charging stoppage. Moreover, under series charging conditions, there is a lack of a unified SOC estimation strategy, making it impossible to synchronously correct the system SOC when the charging of the two packs is unbalanced, posing risks of overcharging and insufficient capacity utilization. Summary of the Invention

[0003] The purpose of this invention is to provide a SOC estimation and control method and related equipment for high and low voltage dual battery packs under multiple operating conditions, in order to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions that enable accurate estimation and unified display of SOC for dual battery packs under different operating conditions such as series connection, parallel connection and single pack independent operation, eliminate the phenomenon of falsely high or low SOC caused by the voltage difference between the two packs or the fault of a single pack, thereby truly representing the remaining power of the system, avoiding overcharging and over-discharging and improving the accuracy of the vehicle's range judgment.

[0004] On one hand, this application provides a SOC estimation and control method for a dual-battery pack with high and low voltage operating conditions, applicable to a dual-battery pack system including a first battery pack and a second battery pack. The method includes the following steps: The battery management system independently estimates the original SOC values ​​of the first battery pack and the second battery pack, and records them as the SOC value of the first battery pack and the SOC value of the second battery pack. The system acquires the status of the high-voltage contactor, battery fault signals, and vehicle charging / discharging commands to identify the current operating mode. The operating modes include: dual-packet parallel discharge mode, dual-packet parallel charging mode, fault isolation single-packet mode, differential voltage degradation single-packet mode, and dual-packet series fast charging mode. Based on the identified working mode, match the corresponding system SOC calculation rules, calculate and output the system SOC; In the dual-pack parallel discharge mode, the dual-pack parallel charging mode, the differential voltage degradation single-pack mode, and the dual-pack series fast charging mode, the system SOC is calculated based on the minimum value between the SOC value of the first battery pack and the SOC value of the second battery pack, as well as the SOC range between the two packs. In the fault isolation single-pack mode, the system SOC is equal to the original SOC value of the currently operational fault-free battery pack.

[0005] Furthermore, the determination condition for the fault isolation single-pack mode is as follows: if an unrecoverable fault is detected in the first battery pack or the second battery pack, the high-voltage circuit of the faulty battery pack is locked, and only the fault-free battery pack is allowed to work; the unrecoverable fault includes insulation fault, relay fault, over-temperature fault or over-voltage fault.

[0006] Furthermore, the method also includes fault recovery switching logic: After the fault in the faulty battery pack is eliminated, wait for a preset time to allow the high voltage signal to stabilize and meet the conditions for parallel charging, then automatically exit the SOC calculation rules in the fault isolation single pack mode and switch back to the capacity conversion logic calculation system SOC in the dual pack parallel discharge mode or the dual pack parallel charging mode. If the SOC of the new computing system after switching is greater than the SOC displayed on the current instrument, the SOC displayed on the instrument will remain unchanged until the SOC of the new computing system is lower than the SOC displayed on the instrument, at which point it will follow the current SOC. If the SOC of the new computing system after switching is less than the SOC displayed on the instrument, then the SOC displayed on the instrument is controlled to quickly follow the SOC of the new computing system according to a set slope.

[0007] Furthermore, the determination condition for the differential voltage degradation single-pack mode is: the total voltage difference between the first battery pack and the second battery pack is greater than the preset differential voltage threshold, and the battery pack with the higher voltage is put into operation first. When the voltage difference between the two battery packs is less than the preset voltage difference threshold and the circuit current is less than the preset current threshold, the battery pack with the lower voltage is connected in parallel, and the system switches to the dual-pack parallel discharge mode or the dual-pack parallel charging mode.

[0008] Furthermore, in the differential pressure degradation single-pack mode, the battery management system limits the parallel output power for amplitude limiting protection, and the system SOC calculation rule continues to use the capacity conversion logic.

[0009] Furthermore, the dual-packet series fast charging mode also includes a charging topology switching step based on the SOC range: Calculate the SOC range between the two packs, where the SOC range between the two packs is the absolute value of the difference between the SOC value of the first battery pack and the SOC value of the second battery pack; If the SOC difference between the two packs is greater than the equalization threshold, the battery management system switches from the dual-pack series fast charging mode to the single-pack charging mode, charging only the low SOC battery pack separately. Once the voltage difference between the two battery packs meets the preset conditions, the system switches back to the parallel charging mode or the series fast charging mode to continue charging, and updates the system SOC based on the dynamically refreshed SOC values ​​of the first and second battery packs. When the SOC of any battery pack reaches the charging cutoff threshold, the system SOC is locked and charging is terminated.

[0010] Furthermore, the step of independently estimating the original SOC values ​​of the first battery pack and the second battery pack specifically includes: Perform cell voltage correction, current integration, and capacity decay compensation on the first battery pack and the second battery pack respectively to obtain their respective base SOC values; When the open-circuit voltage correction condition is met, the SOC values ​​of the first battery pack and the second battery pack are respectively corrected for open-circuit voltage, and the operating mode is re-identified based on the corrected SOC values ​​to match the corresponding system SOC calculation rules.

[0011] On the other hand, this application provides a high- and low-voltage dual-battery pack system, comprising: First battery pack and second battery pack; A battery management unit and a battery disconnection unit connected to the first battery pack and the second battery pack; High-voltage electrical architecture for enabling series-parallel switching of battery packs; And a controller configured to perform the aforementioned SOC estimation control method for high and low voltage dual battery packs under multiple operating conditions.

[0012] On the other hand, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the aforementioned SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions.

[0013] On the other hand, this application provides a vehicle including the aforementioned high- and low-voltage dual battery pack system.

[0014] The beneficial effects of this invention are as follows: This application provides a SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions. This invention independently estimates the original SOC values ​​of the first and second battery packs, and accurately identifies the current system's operating mode based on the high-voltage contactor status, battery fault signals, and vehicle charging and discharging commands. It then matches the corresponding system SOC calculation rules, effectively solving the problem of inaccurate SOC estimation under multiple operating conditions. In dual-pack parallel discharge, dual-pack parallel charging, voltage differential degradation single-pack, and dual-pack series fast charging modes, the system SOC is calculated based on the minimum of the original SOC values ​​of the two packs and the SOC range between the two packs. This accurately represents the system's true available remaining power, avoiding the phenomenon of artificially high or low SOC due to excessive voltage difference between the two packs, and preventing premature power limiting or premature charging stoppage. In fault isolation single-pack mode, the system SOC is directly equal to the original SOC value of the currently operating fault-free battery pack, ensuring that the remaining power displayed on the instrument panel is accurate and reliable during single-pack emergency driving or independent charging. This helps the driver accurately judge the driving range, improving the safety of vehicle operation and the utilization rate of battery capacity. This application also provides related equipment for the above method. The beneficial effects of the related equipment are similar to those of the above method, and will not be described in detail here.

[0015] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0017] Figure 1 This is a flowchart of the SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions provided in this application; Figure 2 This is a schematic diagram of the high-low voltage switching architecture of the dual-battery pack compatible system provided in this application; Figure 3 This is a schematic diagram of the SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions provided in this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] The present application will be further described below with reference to the accompanying drawings and specific embodiments. The described embodiments should not be considered as limitations on the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0020] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0022] With the development of new energy vehicle technology, in order to balance charging speed and infrastructure compatibility, a dual-battery pack architecture with high-low voltage switching has gradually become the mainstream technical solution. This architecture typically includes two battery packs with lower rated voltages, and flexible voltage transformation is achieved through switching via a high-voltage contactor. When high-power DC fast charging is required, the two battery packs are connected in series to receive charging at a high voltage, thereby reducing current heat loss and improving charging efficiency; while in daily driving discharge or AC slow charging scenarios, the two battery packs switch to a parallel connection to provide a stable voltage output.

[0023] In addition, to ensure the reliability and safety of the vehicle, the system is designed with a redundant operating mode, which allows the system to degrade to a single battery pack mode to continue driving or charging independently when one of the battery packs fails and is isolated, or when the voltage difference between the two battery packs is too large to be connected in parallel.

[0024] Existing battery management systems (BMS) mostly rely on the control logic of traditional single battery packs or fixed parallel battery arrays for state-of-charge (SOC) estimation. In traditional parallel systems, due to the direct electrical connection between battery packs, the terminal voltages are forced to remain consistent. Therefore, existing technologies typically assume that the SOCs of the parallel battery packs tend to be synchronized, or simply use weighted average methods or voltage lookup table methods to calculate the remaining capacity of the entire system. This approach is applicable when battery pack consistency is good and operating conditions are simple. However, when faced with complex series-parallel switching and fault redundancy conditions, its algorithm logic appears too simplistic and lacks specificity, failing to distinguish the differences in capacity calculation under different circuit topologies.

[0025] This existing estimation logic has significant flaws when dealing with dual-battery pack systems that switch between high and low voltage. First, in parallel operation, if the two battery packs have a large voltage difference due to differences in aging or initial conditions, although the voltage will be forced to balance after parallel connection, their actual remaining capacities will not be the same. Existing technology, which simply takes an average or estimates based solely on terminal voltage, will cause the displayed state of charge to deviate significantly from the actual usable energy of the system, leading to misjudgments of driving range by the driver. Second, in series fast charging mode, current flows through both battery packs simultaneously. If their capacities or internal resistances are inconsistent, the rates of change of state of charge will differ. Existing technology lacks a corresponding coordinated estimation strategy, which can easily lead to the "weakest link" effect, causing the system to stop charging prematurely or posing a risk of overcharging.

[0026] More seriously, when the system enters fault isolation single-packet mode or differential pressure degradation single-packet mode, existing technologies often cannot flexibly switch the display logic. The system may still use the calculation formula for dual-packet operation, failing to eliminate the influence of faulty or offline packs, resulting in the instrument panel displaying an inaccurately high or low state of charge. For example, when only one battery pack is operational, if the system still uses the total capacity of both packs as the benchmark for calculation, it will cause the displayed power level to jump instantly, causing user panic or misleading them.

[0027] Furthermore, during parallel charging and discharging, existing technologies do not perform refined capacity calculations based on the difference between the states of charge of the two packs. This makes it impossible to accurately characterize the actual available remaining power of the system under non-ideal balance conditions, which can easily cause the vehicle to limit power output in advance or the charging gun to trip prematurely, seriously affecting the user's driving experience and the utilization rate of the battery system.

[0028] To address the aforementioned issues, this invention provides a SOC estimation and control method and related equipment for high- and low-voltage dual-battery packs under multiple operating conditions, establishing a dynamic estimation mechanism deeply coupled with the system topology and operating status. This method first independently estimates the original SOC value of each battery pack and monitors the high-voltage contactor status, fault signals, and charging / discharging commands in real time, thereby accurately identifying various operating modes such as parallel charging / discharging of dual packs, series fast charging of dual packs, fault-isolated single-pack operation, and voltage differential degradation single-pack operation. For different modes, the system matches differentiated calculation strategies: under multi-pack collaborative operating conditions such as parallel and series connections, capacity is calculated based on the minimum and range of the SOC of the two packs to eliminate estimation deviations caused by voltage differentials; under single-pack independent operation conditions, the original SOC of the fault-free battery pack is directly used as the system display value. This scheme achieves adaptive switching of the SOC estimation logic to changes in circuit topology, ensuring the accuracy and consistency of power display under all operating conditions.

[0029] First, the SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions provided in this application will be described in detail below with reference to the accompanying drawings. This method is applied to a dual battery pack system including a first battery pack and a second battery pack.

[0030] Reference Figure 1 The implementation process of the SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions provided in this application embodiment includes, but is not limited to, the following steps.

[0031] In step S110, the battery management system independently estimates the original SOC values ​​of the first battery pack and the second battery pack, and records them as the SOC value of the first battery pack and the SOC value of the second battery pack.

[0032] In step S110, the independence and accuracy of the data source are established to provide reliable raw data support for logical judgments under subsequent complex operating conditions. In a dual-battery pack system, although the two battery packs may switch between series or parallel connections in terms of electrical connection, they are often two independent entities in terms of electrochemical characteristics, aging degree, self-discharge rate, and current remaining capacity. Therefore, the battery management system abandons the crude approach of treating the two packs as a single black box for unified estimation in traditional technology, and instead first estimates the original SOC values ​​of the first and second battery packs independently.

[0033] This step ensures that the system can monitor the true state of energy of each individual battery pack in real time. Regardless of subsequent changes in the circuit topology, the system always has two accurate reference data: the SOC value of the first battery pack and the SOC value of the second battery pack.

[0034] This independent estimation mechanism effectively avoids averaging errors caused by inconsistencies between the two battery packs. It is a prerequisite for subsequent refined capacity conversion and range analysis, and fundamentally solves the technical pain point of blindly averaging and obscuring the true state of individual battery packs.

[0035] Step S120: Obtain the status of the high-voltage contactor, battery fault signal, and vehicle charging / discharging command, and identify the current operating mode of the system.

[0036] The operating modes include: dual-packet parallel discharge mode, dual-packet parallel charging mode, fault isolation single-packet mode, differential voltage degradation single-packet mode, and dual-packet series fast charging mode.

[0037] In step S120, the limitations of traditional BMS in understanding battery pack operating scenarios are overcome, enabling accurate identification of the complex and ever-changing vehicle operating environment. In the high-low voltage switching architecture, the battery pack connection method and load conditions are highly dynamic, and voltage and current data alone cannot fully represent the system's true operating logic. Therefore, this step constructs a multi-dimensional state recognition model by comprehensively collecting three types of key information: high-voltage contactor status, battery fault signals, and vehicle charging and discharging commands. The high-voltage contactor status directly reflects whether the battery pack is in a series, parallel, or independent physical topology; the battery fault signal is used to determine whether there is a single cell failure or system isolation requirement; and the vehicle charging and discharging commands clarify the direction of energy flow.

[0038] Based on this information, the system can accurately determine whether it is currently in a normal and efficient operating condition such as dual-packet parallel discharge, dual-packet parallel charging, or dual-packet series fast charging, or in an abnormal or redundant operating condition such as fault isolation of a single pack or differential voltage degradation of a single pack. This refined pattern recognition is the foundation for realizing dynamic switching of SOC strategy, ensuring that the system will not incorrectly call the dual-packet algorithm when running a single pack, nor will it ignore the inconsistency between the two packs when performing series fast charging.

[0039] Step S130: Based on the identified working mode, match the corresponding system SOC calculation rules, calculate and output the system SOC.

[0040] In step S130, based on the specific working mode identified in the previous steps, the optimal SOC calculation strategy is dynamically matched and executed, thereby outputting an SOC value that best reflects the user's actual experience and truly represents the system's remaining capacity. This step completely solves the problem of the single and rigid algorithm logic in existing technologies, and achieves adaptive coupling between the estimation logic and physical conditions.

[0041] Specifically, in parallel charging and discharging of two battery packs, voltage differential degradation of a single battery pack, and series fast charging of two battery packs, the system no longer simply takes the average value. Instead, it adopts a capacity calculation algorithm based on the minimum SOC and range of the two packs. This algorithm fully considers the "weakest link" effect, meaning that the actual usable capacity of the system is often limited by the battery pack with the lower capacity or poorer performance. By introducing range correction, it can accurately represent the true usable remaining capacity under non-ideal balance conditions, effectively preventing sudden vehicle breakdowns due to falsely high display values ​​or wasted charging capacity due to falsely low display values.

[0042] In fault isolation single-packet mode, this step directly switches the logic, locking the system SOC to the original SOC value of the currently operational, fault-free battery pack, completely eliminating interference from faulty pack data. Through this precise calculation based on different scenarios and strategies, this step ensures that the SOC displayed on the dashboard accurately and linearly reflects the vehicle's range, whether during high-speed fast charging, daily commuting, or emergency driving, greatly improving the user's driving safety and the utilization rate of the battery system.

[0043] In some embodiments of this application, step S110, which involves independently estimating the original SOC values ​​of the first battery pack and the second battery pack, specifically includes: Step S210: Perform single-cell voltage correction, current integration, and capacity decay compensation on the first battery pack and the second battery pack respectively to obtain their respective basic SOC values.

[0044] In step S210, a high-precision single-cell battery pack state baseline is constructed through multi-dimensional algorithm fusion, thereby providing reliable data support for subsequent dual-pack collaborative control. In this step, the battery management system does not rely on a single measurement method, but instead executes a rigorous composite estimation process for both the first and second battery packs.

[0045] First, through single-cell voltage correction, the system can monitor and correct the voltage deviation of each cell in the battery pack in real time, eliminating measurement errors caused by sensor accuracy or cell inconsistency. Second, using high-precision current integration technology, the system accumulates the charge flow during charging and discharging in real time, capturing the dynamic changes in the battery pack's charge in a short period of time. Finally, by introducing a capacity decay compensation mechanism, the system dynamically corrects the nominal total capacity of the battery based on the battery pack's historical usage data, cycle count, and health status.

[0046] This process is crucial because as the battery ages, its actual usable capacity continuously decreases. Without compensation, the SOC calculated based on the initial capacity will show significant deviations. Through the comprehensive processing of these three levels, step S210 ensures that the output base SOC value not only reflects the current charge amount but also truly characterizes the actual energy level of the battery pack in its current aging state, solving the problem of SOC estimation drifting over time due to neglecting battery aging characteristics in traditional methods.

[0047] Step S220: When the open-circuit voltage correction condition is met, the SOC values ​​of the first battery pack and the second battery pack are respectively corrected for open-circuit voltage, and the working mode is re-identified based on the corrected SOC values, and the corresponding system SOC calculation rules are matched.

[0048] In step S220, the fixed physical mapping relationship between open-circuit voltage and SOC is utilized to eliminate the accumulated error generated by the current integration algorithm during long-term operation, and based on this, the system's operating mode is reconfirmed and dynamically adjusted. In actual operation, relying solely on current integration is insufficient to avoid the accumulation of small measurement deviations over time, causing the estimated value to deviate from the true value.

[0049] Therefore, this step sets strict open-circuit voltage correction conditions. When the battery pack is at rest or under specific operating conditions, the system reads the battery pack's terminal voltage and maps it to a standard open-circuit voltage SOC value. This value is then used as a benchmark to forcibly correct or weight the SOC value calculated in step S210. More importantly, this step does not stop at numerical correction but further feeds the corrected high-precision SOC value back to the pattern recognition layer to re-identify the current operating mode.

[0050] This means that if the corrected SOC value shows a drastic change in the pressure difference or charge difference between the two battery packs, the system may determine that the current parallel or series connection conditions are no longer met, thus triggering a switch in operating mode. For example, if the system finds that the pressure difference between the two packs is too large after correction, it may automatically switch from parallel mode to a single-pack mode with reduced pressure difference.

[0051] This closed-loop feedback mechanism based on high-precision correction values ​​ensures that the matching of the system's SOC calculation rules is always based on the most accurate battery state, effectively preventing mode misjudgment caused by estimation errors and guaranteeing the safety and logical closed loop of the vehicle control strategy.

[0052] In some embodiments of this application, in the dual-pack parallel discharge mode, dual-pack parallel charging mode, differential voltage degradation single-pack mode, and dual-pack series fast charging mode, the system SOC is calculated based on the minimum value between the SOC values ​​of the first battery pack and the second battery pack, as well as the SOC range between the two packs.

[0053] Specifically, under the four key operating conditions of parallel discharge of dual packs, parallel charging of dual packs, single pack operation with voltage drop degradation, and fast charging of dual packs in series, the differences in voltage difference, internal resistance difference, or capacity decay degree between battery packs will lead to significant differences in the rate of change of state of charge or the actual usable energy.

[0054] Traditional technologies often use a simple arithmetic average to represent the system's battery capacity. This approach can mask the true state of the low-capacity battery pack when there are significant differences between the two packs. As a result, the system may display a seemingly sufficient remaining capacity, but the actual usable capacity may have been exhausted prematurely due to the weaker battery pack.

[0055] This step establishes the fundamental principle of estimating overall range based on the actual limitations of the system by locking the minimum value between the first and second battery pack states of charge (SOC) as the calculation benchmark. Simultaneously, the introduction of the SOC range difference between the two packs as a correction factor for capacity reduction means that the system not only considers the current minimum charge level but also quantifies the degree of inconsistency between the two battery packs, using the range data to dynamically discount or compensate for the total capacity.

[0056] This processing method can accurately reflect the effective remaining power that the driver can actually use under non-ideal balance conditions, after deducting losses due to pressure difference balance or protection redundancy. This avoids the risk of sudden power loss or power limitation during vehicle operation caused by inflated power levels, and also prevents the waste of charging capacity due to overly conservative estimates. It achieves accuracy and practicality in displaying the remaining power of the system under all operating conditions.

[0057] In some embodiments of this application, in fault isolation single-packet mode, the system SOC is equal to the original SOC value of the currently operational fault-free battery pack. Specifically, this achieves absolute alignment between the system-level SOC and the physically available energy, completely eliminating the display logic confusion caused by faulty pack data interference under redundant architecture. When the system determines that it has entered fault isolation single-packet mode, it means that the high-voltage energy source of the entire vehicle has undergone a fundamental physical change. If the calculation logic of dual-packet collaborative operation is continued at this time, it will inevitably lead to a serious discrepancy between the displayed value and the actual range capability.

[0058] Therefore, this step ensures that the information conveyed to the driver by the dashboard is entirely based on the current state of the single battery pack actually performing work, eliminating any historical data or virtual weights from offline faulty packs. This direct mapping strategy ensures that when a serious fault causes the system to degrade, the remaining battery level seen by the user is accurate and reliable. It avoids misjudgments of range anxiety caused by false battery levels including faulty packs, and it also avoids obscuring the true situation of halved vehicle range due to algorithmic smoothing, providing the most accurate data support for the driver's decision-making in emergency situations.

[0059] In some embodiments of this application, the determination condition for the fault isolation single-packet mode is as follows: if an unrecoverable fault is detected in the first or second battery pack, the high-voltage circuit of the faulty battery pack is locked, and only the fault-free battery pack is allowed to operate. Unrecoverable faults include insulation faults, relay faults, over-temperature faults, or over-voltage faults.

[0060] Specifically, this step establishes the trigger threshold and safety boundary for the fault isolation single-package mode. Through stringent fault determination logic and high-voltage circuit control strategies, it ensures that the system can maintain the highest level of electrical safety even when sacrificing some performance for redundancy.

[0061] This step clearly defines the specific scope of unrecoverable faults, covering serious anomalies that directly threaten the safety of the vehicle and its occupants, such as insulation faults, relay faults, over-temperature faults, and over-voltage faults. Once any of these faults is detected, the system determines that the battery pack is no longer suitable for continued service and must immediately execute an isolation procedure. Its core action is to lock the high-voltage circuit of the faulty battery pack, physically severing the electrical connection between the faulty pack and the vehicle's high-voltage bus, preventing the fault from spreading or causing secondary accidents.

[0062] Simultaneously, logically only fault-free battery packs are allowed to operate. This not only restructures the system's operating mode but also provides a protective takeover of the remaining healthy battery packs. Through this judgment and execution mechanism, this step achieves closed-loop control from fault identification to system reconstruction, ensuring that even in the extreme case of single-pack failure, the dual-battery-pack architecture can still provide reliable power output relying on the remaining healthy units. This truly leverages the core value of the dual-pack architecture's redundancy design—maximizing the vehicle's survivability while ensuring safety.

[0063] In some embodiments of this application, the method further includes fault recovery switching logic: Step S310: After the fault of the faulty battery pack is eliminated, wait for a preset time to allow the high voltage signal to stabilize and meet the conditions for parallel charging, then automatically exit the SOC calculation rules in the fault isolation single pack mode and switch back to the capacity conversion logic calculation system SOC in the dual pack parallel discharge mode or dual pack parallel charging mode.

[0064] In step S310, a safe and smooth system mode transition mechanism is constructed to ensure that after the fault is eliminated, the battery management system can seamlessly and reliably transition from the emergency single-pack operation state back to the efficient dual-pack collaborative state. This step first sets a strict recovery threshold, requiring a preset waiting period after the faulty battery pack is eliminated. This is not only to allow the high-voltage signal to stabilize sufficiently at the physical level and eliminate the interference of transient fluctuations on system judgment, but also to confirm that the fault has been completely eliminated rather than being an occasional fluctuation.

[0065] Based on this, the system needs to further verify whether the conditions for parallel connection are met, that is, to confirm that the key parameters such as voltage and temperature of the two battery packs are within the safe range for parallel connection, to prevent huge circulating current impacts caused by forced parallel connection. Only when all these prerequisites are met will the system automatically exit the SOC calculation rules in the fault isolation single-packet mode and reactivate the capacity conversion logic in the dual-packet parallel discharge mode or dual-packet parallel charging mode.

[0066] This process enables dynamic reconfiguration of the control strategy, ensuring that the system's SOC calculation method remains highly consistent with the current physical topology. This restores the capacity advantage of the dual-package architecture while avoiding electrical risks that may be triggered during mode switching.

[0067] Step S320: If the SOC of the new computing system after switching is greater than the SOC displayed on the current instrument, then keep the SOC displayed on the instrument unchanged until the SOC of the new computing system is lower than the SOC displayed on the instrument, and then follow up.

[0068] In step S320, the issue of fluctuating SOC values ​​during system mode switching is addressed by introducing a hysteresis-following strategy. This effectively prevents user confusion and distrust caused by a sudden increase in battery level. After fault recovery and reconnection of the dual-packet logic, due to changes in the calculation algorithm or the power consumption of the healthy battery pack during single-pass driving, the newly calculated system SOC value may be higher than the SOC value currently displayed on the instrument panel. If the instrument panel is directly updated to the higher new value at this time, it will give the driver the illusion that the battery level has increased out of nowhere, seriously affecting the user experience and judgment of the vehicle's status.

[0069] Therefore, this procedure stipulates that when the newly calculated system SOC after switching is greater than the current instrument panel SOC, the system forcibly maintains the instrument panel SOC unchanged, keeping the current displayed value. Only when the vehicle continues to run, causing the newly calculated system SOC to gradually decrease with power consumption until it falls below the currently displayed value on the instrument panel, will the instrument panel display begin to decrease in line with the new calculated value. This smooth processing logic of only decreasing and not increasing cleverly masks the data fluctuations caused by the background algorithm switching, ensuring that the power display from the user's perspective has continuity and monotony, which conforms to the driver's psychological expectation of continuous power consumption.

[0070] Step S330: If the new computing system SOC after switching is less than the instrument display SOC, then control the instrument display SOC to quickly follow the new computing system SOC according to the set slope.

[0071] Step S330 focuses on handling another extreme case: rapid correction and risk warning when mode switching causes a significant reduction in calculated battery level, preventing vehicle breakdown due to inflated battery display. When the system switches from fault mode back to dual-packet mode, if the new system SOC calculated based on the dual-packet capacity conversion logic is much lower than the current instrument panel SOC, this usually means that the previous estimate during single-packet operation was overly optimistic, or that the system's bottleneck effect after dual-packet parallel operation resulted in a significantly lower-than-expected available capacity. If the original high battery display is maintained at this time, the driver may misjudge the remaining driving range and miss the charging opportunity.

[0072] Therefore, this procedure stipulates that once the new computing system's SOC is detected to be lower than the instrument panel's displayed SOC, the system will immediately intervene and control the instrument panel's displayed SOC to quickly follow the new computing system's SOC according to a set slope. This rapid decline display strategy is actually a protective correction mechanism. It corrects the inflated battery level on the instrument panel to the true remaining battery level as quickly as possible. Although it may give the user a visual shock of a sudden decrease in battery power, from a safety perspective, it promptly alerts the driver to the true range, avoiding power interruption caused by blindly optimistic driving, and ensuring the vehicle's operational safety under complex operating conditions.

[0073] In some embodiments of this application, the determination condition for the differential voltage degradation single-pack mode is: the total voltage difference between the first battery pack and the second battery pack is greater than the preset differential voltage threshold. The battery pack with the higher voltage is controlled to start working first. This establishes the triggering logic and priority power supply strategy for the differential voltage degradation single-pack mode, effectively preventing the huge circulating current impact caused by the direct parallel connection of the two battery packs due to the excessive initial voltage difference, thereby ensuring the safety and stability of the vehicle's high-voltage electrical system.

[0074] In actual operation, due to differences in the aging or charging state of the battery packs, there may be a significant voltage difference between the two battery packs. If the contactor is directly closed for parallel connection, the high-voltage battery pack will generate a very large instantaneous charging current to the low-voltage battery pack, which can easily burn out the relay or trigger the overcurrent protection. Therefore, this step sets a strict voltage difference threshold as a safety boundary. Once the total voltage difference between the two packs is detected to be greater than this threshold, the system will actively prohibit parallel connection and force the higher-voltage battery pack to be put into operation first to provide power to the vehicle or receive charging.

[0075] This "single-to-double" downgraded operation strategy ensures that the vehicle still has basic driving or charging capabilities under abnormal voltage difference conditions, while also providing a time window for the lower voltage battery pack to gradually catch up with the voltage through small current charging and discharging, fundamentally eliminating the safety hazards caused by large voltage difference battery packs.

[0076] Furthermore, when the voltage difference between the two battery packs is less than a preset voltage difference threshold and the circuit current is less than a preset current threshold, the battery pack with the lower voltage is connected in parallel, and the system switches to a dual-pack parallel discharge mode or a dual-pack parallel charging mode. In this way, a smooth switching mechanism is constructed from single-pack degraded operation to dual-pack parallel collaborative operation, ensuring that the battery packs achieve true electrical balance at the physical level before resuming dual-pack collaborative operation, so as to maximize the utilization of the vehicle's capacity and performance.

[0077] During operation in differential pressure degradation single-pack mode, the system continuously monitors the voltage status of the two battery packs and the current magnitude of the loop. Only when the voltage difference between the two battery packs decreases to within a preset differential pressure threshold and the loop current also drops below a preset current threshold will the system determine that the current electrical environment meets the conditions for safe battery pack operation.

[0078] At this point, the system will control the integration of the battery pack into the system, safely integrating the lower-voltage battery pack and automatically switching to a dual-pack parallel discharge mode or a dual-pack parallel charging mode. This closed-loop control logic, based on the dual constraints of "voltage difference" and "current," completely avoids the risk of secondary circulating current caused by load fluctuations or current surges when the battery packs are not fully balanced. This ensures the efficiency and safety of the dual-pack architecture when resuming collaborative operation, achieving an optimal balance between safety and performance in the system's operating state.

[0079] In some embodiments of this application, under the differential pressure degradation single-pack mode, the battery management system limits the parallel output power for limiting protection, and the system SOC calculation rule still adopts the capacity conversion logic.

[0080] Specifically, a dual safety and computational assurance mechanism was constructed under the differential pressure degradation single-package mode. Through power limiting and algorithm continuation, the electrical safety and continuity of power display of the system under non-ideal parallel conditions are ensured. In this mode, although the system is nominally in a dual-package architecture, due to the excessive differential pressure, true electrical parallel connection is not actually achieved, or the system is in a highly unstable critical state.

[0081] At this time, the battery management system actively limits the parallel output power for amplitude protection, which can effectively prevent the low-voltage battery pack from being reverse-charged due to forced high power output, or the high-voltage battery pack from triggering a secondary fault due to overload, thereby avoiding damage to high-voltage components by high current surge.

[0082] At the same time, the system's SOC calculation rules continue to use capacity discounting logic, which means that even during power-constrained degraded operation, the system still uses a complex algorithm based on minimum value and range correction, rather than simply reverting to single-packet display.

[0083] This approach ensures that the SOC estimate can reflect the impact of inconsistencies between the two battery packs on the actual usable capacity in real time. It guarantees that during the entire transition phase before the pressure difference returns to equilibrium, the remaining power displayed on the instrument is always based on the actual usable energy under the current limited operating conditions, providing the driver with an accurate and safe range reference.

[0084] In some embodiments of this application, in the dual-packet series fast charging mode, a charging topology switching step based on the SOC range is also included: Step S410: Calculate the SOC range between the two battery packs. The SOC range between the two battery packs is the absolute value of the difference between the SOC values ​​of the first battery pack and the SOC values ​​of the second battery pack.

[0085] In step S410, a pre-judgment step is provided for the equalization control logic in the dual-pack series fast charging mode, which quantitatively characterizes the degree of inconsistency in the state of charge between the first battery pack and the second battery pack, providing accurate data support for subsequent mode switching decisions.

[0086] In this step, the system collects and calculates the absolute value of the difference between the SOC values ​​of the first and second battery packs in real time to determine the SOC range between the two packs. This parameter is a key indicator for measuring the balancing requirements of the dual-pack system. Under the high-voltage and high-current conditions of series fast charging, the capacity or internal resistance differences between the battery packs will be amplified. If this range is not monitored in time, the lower-capacity battery pack may reach the full-charge cutoff voltage prematurely, triggering overcharge protection and forcing the entire charging process to terminate prematurely.

[0087] By accurately calculating the SOC difference between the two charging units, the system can keenly detect the dispersion trend of the dual-unit power, thereby determining whether there is a physical basis to continue maintaining the series fast charging mode, or whether an active balancing strategy needs to be intervened.

[0088] In step S420, if the SOC difference between the two packs is greater than the balancing threshold, the battery management system switches from the dual-pack series fast charging mode to the single-pack charging mode, charging only the low-SOC battery pack separately.

[0089] In step S420, a dynamic charging topology reconfiguration mechanism based on the SOC difference is established to address the "weakest link" effect in the series charging architecture. By switching topologies, the power bottleneck between battery packs is eliminated, thereby maximizing the overall charging capacity of the system. When the SOC difference between two battery packs is detected to be greater than a preset balancing threshold, it indicates that the power difference between the two battery packs has become too large to be compensated for by conventional end-point balancing. Continuing series charging will lead to the risk that the low-power pack will not be fully charged while the high-power pack is overcharged.

[0090] At this point, the battery management system decisively switched from the dual-pack series fast charging mode to the single-pack charging mode, and precisely targeted only the low-SOC battery pack for separate charging. This strategy is equivalent to inserting a "recharge" stage in the middle of the charging process, specifically providing "special attention" capacity compensation to the battery pack with lagging power, so that its power level can quickly catch up with the high-power pack.

[0091] This dynamic switching not only avoids charging interruptions caused by single-cell overvoltage, but also fundamentally solves the problem of usable capacity decay caused by inconsistency in dual-pack systems, ensuring that the two battery packs can reach full charge synchronously in subsequent stages.

[0092] Step S430: After the voltage difference between the two battery packs meets the preset conditions, switch back to the dual-pack parallel charging mode or the dual-pack series fast charging mode to continue charging, and update the system SOC according to the dynamically refreshed SOC values ​​of the first and second battery packs.

[0093] In step S430, a closed-loop control logic is constructed to return from single-pack charging mode to system-level collaborative charging. This ensures that after the battery pack completes power balancing, it can safely and efficiently resume the standard charging process and update the system-level power display in real time. In single-pack charging mode, as the low-SOC battery pack's power continuously recovers, the system continuously monitors the voltage difference between the two battery packs. Once the voltage difference meets the preset parallel or series conditions, it means that the state of charge of the two battery packs has become consistent, eliminating the risk of electrical mismatch.

[0094] At this point, the system will automatically switch back to the dual-pack parallel charging mode or the dual-pack series fast charging mode, utilizing the high-voltage fast charging topology to continue the remaining charging process. Simultaneously, the system will recalculate and update the system SOC based on the dynamically refreshed SOC values ​​of the first and second battery packs.

[0095] This step ensures that the background power estimation model remains synchronized with the physical connection status during frequent switching of charging topology, avoiding power jumps or estimation lags caused by mode changes, and providing the vehicle controller with continuous and reliable power data.

[0096] Step S440: When the SOC of any battery pack reaches the charging cutoff threshold, lock the system SOC and terminate charging.

[0097] Step S440 sets the ultimate safety boundary and termination criteria for the charging process to prevent overcharging and ensure the cycle life and operational safety of the battery system. Towards the end of charging, the battery voltage is extremely sensitive to changes in SOC; even a small increase in charge can cause a sharp voltage spike. This step stipulates that when the SOC of any battery pack reaches the charging cutoff threshold, the system immediately locks the system SOC and terminates charging. This logic follows the "bottleneck principle," meaning that as long as one battery pack reaches full charge, external energy input must be stopped regardless of whether the other battery pack is fully charged.

[0098] This is because in a dual-pack architecture, continuing to force charging can cause the fully charged battery pack to enter the overcharge zone, which can easily lead to serious safety accidents such as electrolyte decomposition, gas production, or even thermal runaway. By locking the system's State of Charge (SOC), the system clearly communicates to the user that the vehicle has reached its maximum available charge level, preventing the user from mistakenly believing that there is still charging space remaining. This physically eliminates the risk of overcharging and ensures that every charging process is completed within the battery's safe electrochemical window.

[0099] In some embodiments of this application, reference is made to Figure 2 This demonstrates the high-low voltage switching architecture of a high-low voltage compatible dual-battery pack system. The system comprises two battery packs (A and B), each equipped with a Battery Management Unit (BMU) and a Battery Disconnect Unit (BDU). The left side features fast charging, rear drive, PDU interfaces, and a Current Sensor (CSC), while the right side houses a front drive interface, a low-voltage communication module, and another current sensor (CSC). The BDU enables high-voltage on / off control between the battery pack and the fast charging, rear drive, and front drive circuits. The BMU is responsible for battery status monitoring and management, the current sensor (CSC) collects circuit current, and the low-voltage communication module ensures information exchange between systems. The overall architecture supports the power distribution, signal acquisition, and communication functions required for multi-condition SOC estimation control under high-low voltage compatibility.

[0100] In some embodiments of this application, a complete implementation process of a SOC estimation and control method for high- and low-voltage dual-battery packs under multiple operating conditions is given. This method is based on, for example... Figure 2 The high-low voltage switching architecture shown is designed to address the problem of inaccurate estimation of system state of charge (SOC) under complex operating conditions. The specific control flow and logic are as follows: First, the battery management system (BMS) independently estimates the original SOC values ​​of battery pack A and battery pack B, denoted as SOC_A and SOC_B respectively.

[0101] Subsequently, the system accurately identifies the current operating mode based on the high-voltage contactor status, battery fault signal, vehicle charging / discharging commands, and the voltage difference between battery packs A and B. These operating modes primarily include: 400V dual-pack parallel discharge mode, 400V single-pack discharge mode, 400V dual-pack parallel charging mode, 400V single-pack charging mode, and 800V dual-pack series fast charging mode.

[0102] Based on the identified working mode, the system matches the corresponding SOC calculation rules: (1) For single-pack operation mode (fault isolation or excessive voltage difference), when a battery pack malfunctions, or when the total voltage difference between A and B packs is too large, allowing only a single pack to operate, the operation mode is determined to be 400V single-pack discharge or 400V single-pack charging. At this time, the system SOC is directly equal to the original SOC of the currently fault-free, operational single battery pack.

[0103] Furthermore, single-pack discharge judgment conditions are set: if the BMS detects an insulation fault, relay fault, over-temperature fault, or over-voltage fault in pack A or pack B, the high-voltage circuit of the faulty battery pack is locked, and only non-faulty single packs are allowed to work.

[0104] Furthermore, a differential voltage protection strategy is implemented: if the A / B voltage difference is greater than 5V, only the battery pack with the higher voltage is allowed to operate first. Once the voltage difference between the two battery packs is less than 5V and the current is less than 5A (the current threshold can be adjusted according to actual conditions), the battery pack with the lower voltage is then connected. In this differential voltage degradation single-packet mode, only the system output power is limited for protection, and the SOC calculation formula remains unchanged (i.e., the following conversion logic is used).

[0105] (2) For dual-packet collaborative and series fast charging modes, when the working mode is 400V dual-packet parallel discharge, 400V dual-packet parallel charging, 800V dual-packet series fast charging, or when single-packet operation is caused by excessive total voltage difference between A and B packs, the system SOC is calculated using the following capacity conversion formula: ; in, The minimum value between SOC_A and SOC_B. It is the maximum value among SOC_A and SOC_B.

[0106] (3) When the working mode is 800V dual-pack series fast charging, it also includes an active balancing step: calculating the SOC difference between the two packs. .like When the voltage exceeds 5%, the BMS actively switches to 400V single-pack charging. Once the voltages of the two packs are comparable, the two battery packs are connected in parallel, and then... , Dynamically refresh the system SOC. When the SOC of any battery pack reaches the charging cutoff threshold, lock the system SOC and terminate charging.

[0107] Furthermore, once the faulty battery pack is cleared, the fault recovery switching logic is executed: wait 0.8 to 1 second for the high-voltage signal to stabilize. Check if the conditions for parallel charging are met (battery pack voltage difference < 5V and current < 5A). If the conditions are met, automatically exit the single-pack SOC calculation rule and switch to the dual-pack conversion formula to calculate the system SOC.

[0108] To prevent the instrument display from fluctuating, the following display strategy is implemented: If the newly calculated system SOC after merging is greater than the displayed SOC_display, the displayed SOC_display remains unchanged until it falls below the displayed SOC_display, at which point it follows the strategy and decreases.

[0109] If the newly calculated system SOC after merging is less than the displayed SOC_display, then the displayed SOC_display can quickly follow along with a certain slope.

[0110] Further, execute the reset and correction logic: Power-on / off reset: After the vehicle is powered on again and the BMS initialization is completed, the voltage and current signals of packages A and B are collected again, the SOC_A and SOC_B are re-estimated, and the working mode is re-matched.

[0111] OCV (Open Circuit Voltage) Correction: If the OCV correction condition is met, SOC_A and SOC_B need to be corrected respectively, and the system SOC needs to be recalculated.

[0112] Finally, the calculated system SOC is output to the vehicle controller, instrument panel, and charger for energy management and power display.

[0113] In some embodiments of this application, reference is made to Figure 3 The method first collects the voltage, current and temperature signals of each battery pack through BMS initialization, and calculates the minimum and maximum values ​​of the original SOC of the two battery packs accordingly. Then the system reads the real-time data and performs operating condition judgment.

[0114] During the judgment process, if a permanent fault is detected in a single battery pack, the system will enter fault isolation mode. In this mode, the system's SOC is directly taken as the SOC of the healthy battery pack, and a protection strategy of power allocation to the single pack with energy halved is implemented. If no permanent fault is detected in a single battery pack, the system further determines whether the voltage difference between the two battery packs exceeds 5V. When the voltage difference is greater than 5V, the system controls the high SOC battery pack to work first and calls the conversion formula for calculation; when the voltage difference is not greater than 5V, the system controls both packs to work together and also calls the conversion formula for calculation.

[0115] Ultimately, regardless of whether the system is in fault isolation, high voltage differential priority operation, or dual-packet collaborative operation state, the calculated results will be output as the system SOC to the vehicle controller and instrument panel, thereby achieving accurate estimation and management of the remaining power under different operating conditions.

[0116] Secondly, this application provides a high- and low-voltage dual-battery pack system, including a first battery pack and a second battery pack; a battery management unit and a battery disconnection unit connected to the first battery pack and the second battery pack; a high-voltage electrical architecture for realizing series-parallel switching of the battery packs; and a controller configured to execute the aforementioned high- and low-voltage dual-battery pack multi-condition SOC estimation control method.

[0117] Specifically, the first and second battery packs constitute the physical basis for the vehicle's energy storage and output. As the core carriers of the dual-battery pack architecture, they not only provide the electrical energy required for vehicle driving, but also take into account the needs of high-voltage fast charging and high-power discharge through flexible series and parallel combinations under different operating conditions.

[0118] The battery management unit and the battery disconnection unit work together to form the safety and status awareness center of the system. The former is responsible for real-time monitoring of key parameters such as voltage, current and temperature of each battery pack, and accurately assessing the health status and state of charge of the battery. The latter acts as an actuator, which quickly and safely disconnects or connects the high-voltage circuit when the system detects a fault or needs to switch operating modes, ensuring the absolute safety of the electrical system.

[0119] The high-voltage electrical architecture is the physical channel for realizing flexible topology transformation of dual battery packs. Through the precise cooperation of internal high-voltage contactors and relays, it can seamlessly switch between series and parallel states between the first and second battery packs according to the actual needs of the vehicle, thereby supporting various complex operating conditions such as high-voltage fast charging, parallel discharge, and single-pack redundant operation at the physical level.

[0120] As the brain of the entire high- and low-voltage dual-battery pack system, the controller is specifically configured to execute the aforementioned high- and low-voltage dual-battery pack multi-condition SOC estimation control method. By comprehensively processing real-time data from the battery management unit and the status feedback from the high-voltage electrical architecture, it dynamically identifies the current operating mode and matches the corresponding SOC calculation rules, thereby ensuring that accurate and reliable system remaining power information can be output to the user under various complex operating conditions.

[0121] Furthermore, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the aforementioned SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions.

[0122] Furthermore, embodiments of this application provide a vehicle that includes a high- and low-voltage dual battery pack system as described above, or includes electronic devices as described above.

[0123] In summary, the SOC estimation and control method and related equipment for high and low voltage dual battery packs under multiple operating conditions provided in this application have the following technical effects.

[0124] This application effectively solves the technical challenges of fluctuating battery level and inaccurate estimation in traditional dual-battery pack systems under complex scenarios such as series-parallel switching, fault degradation, and fast charging balancing by constructing a dynamic SOC estimation system based on physical topology and operating conditions. This method not only utilizes capacity conversion logic and range correction mechanisms to achieve accurate quantification and real-time compensation for inconsistencies between the two packs, but also ensures a smooth transition of system SOC between single-pack operation, parallel dual-pack operation, and series fast charging modes. It completely eliminates sudden changes in battery level display caused by mode switching, significantly improving user confidence in the remaining driving range.

[0125] Meanwhile, by combining differential pressure degradation, power limiting, and active balancing topology switching, this system maximizes the available capacity and charging efficiency of the dual-pack system while ensuring high-voltage electrical safety and preventing circulating current impact and battery overcharging. It provides a battery management solution for new energy vehicles that combines high safety, high robustness, and high precision, and has extremely high engineering application value and market promotion prospects.

[0126] It should be noted that in all specific embodiments of this application, when processing data related to user identity or characteristics, such as user information, user behavior data, user historical data, and user location information, user permission or consent is obtained first. Furthermore, the collection, use, and processing of this data comply with relevant laws, regulations, and standards of the relevant countries and regions. In addition, when embodiments of this application require access to sensitive personal information of users, separate permission or consent from the user is obtained through pop-ups or redirects to confirmation pages. Only after obtaining the user's separate permission or consent is the necessary user-related data for the proper functioning of the embodiments of this application obtained.

[0127] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this application are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0128] Furthermore, although this application is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding this application. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of ordinary skill of an engineer. Therefore, those skilled in the art can implement the application set forth in the claims using ordinary skill. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of this application, which is determined by the full scope of the appended claims and their equivalents.

[0129] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several programs to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. 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.

[0130] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable programs for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can retrieve and execute a program from or in conjunction with such a program execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can mean any means that can contain, store, communicate, propagate, or transmit a program for use by or in conjunction with a program execution system, apparatus, or device.

[0131] More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or, if necessary, processing in a suitable manner, and then stored in computer memory.

[0132] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable program execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0133] In the foregoing description of this specification, the reference to terms such as "one embodiment / implementation," "another embodiment / implementation," or "certain embodiments / implementations," etc., indicates that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in an embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0134] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0135] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A method for SOC estimation and control of a high- and low-voltage dual-battery pack under multiple operating conditions, characterized in that, Applied to a dual-battery pack system comprising a first battery pack and a second battery pack, the method includes the following steps: The battery management system independently estimates the original SOC values ​​of the first battery pack and the second battery pack, and records them as the SOC value of the first battery pack and the SOC value of the second battery pack. The system acquires the status of the high-voltage contactor, battery fault signals, and vehicle charging / discharging commands to identify the current operating mode. The operating modes include: dual-packet parallel discharge mode, dual-packet parallel charging mode, fault isolation single-packet mode, differential voltage degradation single-packet mode, and dual-packet series fast charging mode. Based on the identified working mode, match the corresponding system SOC calculation rules, calculate and output the system SOC; In the dual-pack parallel discharge mode, the dual-pack parallel charging mode, the differential voltage degradation single-pack mode, and the dual-pack series fast charging mode, the system SOC is calculated based on the minimum value between the SOC value of the first battery pack and the SOC value of the second battery pack, as well as the SOC range between the two packs. In the fault isolation single-pack mode, the system SOC is equal to the original SOC value of the currently operational fault-free battery pack.

2. The SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions according to claim 1, characterized in that, The determination condition for the fault isolation single-pack mode is as follows: if an unrecoverable fault is detected in the first battery pack or the second battery pack, the high-voltage circuit of the faulty battery pack is locked, and only the fault-free battery pack is allowed to work; the unrecoverable fault includes insulation fault, relay fault, over-temperature fault or over-voltage fault.

3. The SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions according to claim 2, characterized in that, It also includes fault recovery and switching logic: After the fault in the faulty battery pack is eliminated, wait for a preset time to allow the high voltage signal to stabilize and meet the conditions for parallel charging, then automatically exit the SOC calculation rules in the fault isolation single pack mode and switch back to the capacity conversion logic calculation system SOC in the dual pack parallel discharge mode or the dual pack parallel charging mode. If the SOC of the new computing system after switching is greater than the SOC displayed on the current instrument, the SOC displayed on the instrument will remain unchanged until the SOC of the new computing system is lower than the SOC displayed on the instrument, at which point it will follow the current SOC. If the SOC of the new computing system after switching is less than the SOC displayed on the instrument, then the SOC displayed on the instrument is controlled to quickly follow the SOC of the new computing system according to a set slope.

4. The SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions according to claim 3, characterized in that, The determination condition for the differential voltage degradation single-pack mode is: the total voltage difference between the first battery pack and the second battery pack is greater than the preset differential voltage threshold, and the battery pack with the higher voltage is put into operation first. When the voltage difference between the two battery packs is less than the preset voltage difference threshold and the circuit current is less than the preset current threshold, the battery pack with the lower voltage is connected in parallel, and the system switches to the dual-pack parallel discharge mode or the dual-pack parallel charging mode.

5. The SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions according to claim 4, characterized in that, In the differential pressure degradation single-pack mode, the battery management system limits the parallel output power for amplitude limiting protection, and the system SOC calculation rule still adopts the capacity conversion logic.

6. The SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions according to claim 1, characterized in that, The dual-packet series fast charging mode also includes a charging topology switching step based on the SOC range: Calculate the SOC range between the two packs, where the SOC range between the two packs is the absolute value of the difference between the SOC value of the first battery pack and the SOC value of the second battery pack; If the SOC difference between the two packs is greater than the equalization threshold, the battery management system switches from the dual-pack series fast charging mode to the single-pack charging mode, charging only the low SOC battery pack separately. Once the voltage difference between the two battery packs meets the preset conditions, the system switches back to the parallel charging mode or the series fast charging mode to continue charging, and updates the system SOC based on the dynamically refreshed SOC values ​​of the first and second battery packs. When the SOC of any battery pack reaches the charging cutoff threshold, the system SOC is locked and charging is terminated.

7. The SOC estimation and control method for high and low voltage dual battery packs under multiple operating conditions according to claim 1, characterized in that, The step of independently estimating the original SOC values ​​of the first battery pack and the second battery pack specifically includes: Perform cell voltage correction, current integration, and capacity decay compensation on the first battery pack and the second battery pack respectively to obtain their respective base SOC values; When the open-circuit voltage correction condition is met, the SOC values ​​of the first battery pack and the second battery pack are respectively corrected for open-circuit voltage, and the operating mode is re-identified based on the corrected SOC values ​​to match the corresponding system SOC calculation rules.

8. A high- and low-voltage dual-battery pack system, characterized in that, include: First battery pack and second battery pack; A battery management unit and a battery disconnection unit connected to the first battery pack and the second battery pack; High-voltage electrical architecture for enabling series-parallel switching of battery packs; And a controller configured to perform the SOC estimation control method for high and low voltage dual battery packs under multiple operating conditions as described in any one of claims 1 to 7.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the SOC estimation control method for high and low voltage dual battery packs under multiple operating conditions as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, Including the high- and low-voltage dual battery pack system as described in claim 8.

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