Battery discharge depth adjustment method and device, computer device, and storage medium

Abstract

The present application relates to the technical field of battery, and discloses a battery discharge depth adjustment method and device, computer equipment and storage medium, in response to the battery being in a charging state, performing real-time calibration on the state of charge estimation value of the battery, so that the calibrated state of charge estimation value is consistent with the actual state of charge value of the battery, when the single battery voltage reaches the full charge cut-off voltage, ending the real-time calibration of the state of charge estimation value, and generating a battery full charge signal, performing a set operation on the battery full charge signal, so that the battery full charge signal is in a set state, and adjusting the discharge depth of the battery according to the set state. The present application calibrates the state of charge estimation value of the battery in real time to reduce the error with the actual value, and introduces a flag bit after the battery full charge correction, which provides longer pure electric endurance for users under the premise of ensuring the safety of the battery.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a method, apparatus, computer equipment, and storage medium for adjusting the depth of battery discharge. Background Technology

[0002] In conventional vehicle battery charging and discharging management, to prevent performance degradation or battery damage caused by battery state of charge (SOC) deviation, a relatively high threshold is typically set for the battery's discharge limit. When the battery's SOC approaches this higher threshold, the battery actively limits its discharge power to prevent further SOC reduction, thereby maintaining the battery within a safe and stable operating range.

[0003] However, this protection strategy limits the battery's usable capacity, thus shortening the vehicle's pure electric range. Blindly lowering the lower threshold for the battery's state of charge when exiting pure electric priority mode would significantly impact battery health and increase vehicle safety risks. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method, apparatus, computer device, and storage medium for adjusting the depth of battery discharge, in order to solve the problem of how to ensure battery health while lowering the lower limit threshold of the state of charge of the battery when exiting the pure electric priority mode.

[0005] In a first aspect, embodiments of the present invention provide a method for adjusting the depth of battery discharge, the method comprising: In response to the battery being in a charging state, the estimated state of charge of the battery is calibrated in real time to ensure that the calibrated estimated state of charge is consistent with the actual state of charge of the battery. When the voltage of a single cell of the battery reaches the full charge cutoff voltage, the real-time calibration of the estimated state of charge value ends and a full charge signal is generated. A setting operation is performed on the battery full charge signal to put the battery full charge signal in a set state, and the discharge depth of the battery is adjusted according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

[0006] The battery discharge depth adjustment method provided in this invention performs real-time calibration of the battery's estimated state of charge (SOC) in response to the battery being in a charging state. This ensures that the calibrated SOC estimate matches the actual SOC value. When the individual cell voltage reaches the full charge cutoff voltage, the real-time calibration of the SOC estimate ends, and a full charge signal is generated. A setting operation is performed on the full charge signal to keep it in the set state, and the battery discharge depth is adjusted based on this set state. This invention combines high-precision real-time calibration of the battery SOC estimate during the charging process, reducing the cumulative error between the estimated and actual values. Simultaneously, it introduces a flag bit after full charge correction, providing users with longer pure electric range while ensuring battery safety.

[0007] In conjunction with the first aspect, in one embodiment, the vehicle includes a battery management unit; the step of performing real-time calibration of the battery's state of charge estimate in response to the battery being in a charging state includes: Obtain the individual cell voltage and charging current of the battery when it is in a charging state; When the voltage of the single cell is greater than the voltage reference value and the charging current is less than the current reference value, the control battery management unit performs real-time calibration on the estimated state of charge of the battery so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery.

[0008] This process enables the battery management unit to actively synchronize the estimated state of charge (SOC) with the actual SOC of the battery. Ultimately, at full charge, the displayed SOC is forcibly set to 100%, significantly improving the consistency between the vehicle's displayed charge level and the actual remaining battery energy. This eliminates range anxiety for drivers caused by inaccurate SOC displays and provides reliable benchmark data points for further exploration of battery discharge depth.

[0009] In conjunction with the first aspect or its corresponding implementation, in one implementation, the control battery management unit performs real-time calibration of the battery's state of charge estimate, including: Obtain the estimated state of charge of the battery at the single cell voltage; Obtain the performance parameters of the battery, and determine the actual state of charge (SOC) value of the battery at the given single cell voltage and charging current based on the performance parameters. The state of charge correction value of the battery is calculated based on the actual state of charge value and the estimated state of charge value; If the voltage of a single cell does not reach the full charge cutoff voltage of the battery, the estimated state of charge of the battery is updated based on the state of charge correction value until the estimated state of charge is consistent with the actual state of charge.

[0010] This invention utilizes the characteristic that the battery's terminal voltage approximates the open-circuit voltage during the charging phase to calculate the deviation between the estimated state of charge (SOC) and the actual SOC in real time. It then performs iterative corrections throughout the entire charging period, achieving a unified SOC between the estimated and actual values. This provides a precise data foundation for accurately determining the battery's full charge status and improves the accuracy of battery management.

[0011] In conjunction with the first aspect or its corresponding implementation, in one embodiment, the vehicle further includes an electronic control unit; before performing a setting operation on the battery full charge signal, the method includes: The full charge time and current battery temperature of the battery are determined based on the battery full charge signal, and the current health of the battery is determined based on the performance parameters. The battery is judged to meet the first depth of discharge constraint condition based on the full charge time, the battery temperature, and the battery health status; wherein, the first depth of discharge constraint condition is characterized by the full charge time being less than the full charge time threshold, the battery temperature being greater than the battery temperature reference value, and the battery health status being greater than the battery health reference value. When the battery meets the first depth of discharge constraint, the electronic control unit is controlled to set the battery full charge signal.

[0012] The first depth of discharge constraint in this embodiment of the invention is composed of time constraints, temperature constraints, and health constraints. After the electronic control unit receives the battery full charge signal, it further determines the full charge time of the most recent full charge event based on the timestamp of the received full charge signal, and simultaneously collects the actual internal temperature data of the battery, as well as determines the current battery health based on the battery's performance parameters. On this basis, the full charge time, battery temperature, and health are matched and verified against the preset first depth of discharge constraint. Only when all three parameters are confirmed to simultaneously meet the first depth of discharge constraint is the electronic control unit controlled to set the battery full charge signal, thereby improving power utilization efficiency while ensuring the safety and durability of the battery system.

[0013] In conjunction with the first aspect, in one embodiment, after performing a setting operation on the battery full charge signal to put the battery full charge signal in a set state, the method further includes: The environmental parameters of the current environment of the vehicle are detected, and it is determined whether the environmental parameters meet the second depth of discharge constraint condition. The environmental parameters include ambient temperature and ambient altitude. The second depth of discharge constraint condition indicates that the ambient temperature is within a safe temperature range and the ambient altitude is less than an altitude threshold. When the environmental parameters meet the second discharge depth constraint, the discharge depth of the battery is adjusted according to the setting state of the battery full charge signal.

[0014] When the user activates the MaxEV function, the battery discharge depth is reduced, thereby increasing the vehicle's pure electric range. Conversely, if any environmental parameter does not meet the second discharge depth constraint, such as excessively low ambient temperature, excessively high ambient temperature, or excessively high altitude, the adjustment of the battery discharge depth will be limited, and the originally set, safer MaxEV exit threshold will continue to be used. This achieves an intelligent control strategy that balances improving battery range with ensuring safety and reliability under all operating conditions.

[0015] In conjunction with the first aspect, in one embodiment, adjusting the depth of discharge of the battery based on the set state includes: When the battery full charge signal is in an active state, the pure electric priority mode of the battery is activated. In the pure electric priority mode, the state of charge limit threshold of the battery when exiting the pure electric priority mode is reduced, and the first discharge power of the battery when in the pure electric priority function is increased.

[0016] When the lower limit threshold of the battery state of charge corresponding to exiting the pure electric priority mode is lowered, the first discharge power of the battery in the pure electric priority mode will be increased simultaneously, avoiding the vehicle power problems that may occur when the battery state of charge drops to close to the new, lower exit threshold.

[0017] In conjunction with the first aspect or its corresponding implementation, in one implementation, the method further includes: When the battery full charge signal is in an invalid state, or when the activation conditions of the pure electric priority mode are not met, the pure electric priority mode of the battery is turned off, and the hybrid discharge mode of the battery is started. The first discharge power of the battery in the pure electric priority mode is adjusted to the second discharge power of the battery in the hybrid discharge mode.

[0018] When the battery full charge signal is in an invalid state, or the conditions for activating the pure electric priority mode are not met, this embodiment of the invention will disable the pure electric priority mode and default to enabling the battery's hybrid discharge mode. In this conventional hybrid discharge mode, the battery's discharge power is limited to a lower second discharge power level corresponding to the hybrid mode, effectively avoiding vibrations or power surges that may cause discomfort to the driver due to rapid switching of driving modes, thus ensuring the smoothness of the driving process.

[0019] Secondly, embodiments of the present invention provide a battery discharge depth adjustment device, the device comprising: The state of charge calibration module is used to perform real-time calibration on the estimated state of charge of the battery in response to the battery being in a charging state, so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery. The full charge signal transmitting module is used to end the real-time calibration of the estimated state of charge value and generate a battery full charge signal when the voltage of a single cell of the battery reaches the full charge cutoff voltage. The depth of discharge adjustment module is used to perform a setting operation on the battery full charge signal, so that the battery full charge signal is in a set state, and adjust the depth of discharge of the battery according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

[0020] Thirdly, embodiments of the present invention provide a computer device, including: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the battery discharge depth adjustment method of the first aspect or any corresponding embodiment described above.

[0021] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing computer instructions for causing a computer to execute the battery discharge depth adjustment method of the first aspect or any corresponding embodiment described above. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic flowchart of a method for adjusting the depth of battery discharge according to some embodiments of the present invention; Figure 2 This is a structural block diagram of a battery discharge depth adjustment device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] According to an embodiment of the present invention, a method for adjusting the depth of battery discharge is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0026] MaxEV, or Electric Priority Mode, is a driving strategy used in plug-in hybrid or range-extended electric vehicles. MaxEV mode temporarily expands the available battery capacity by adjusting the control threshold of the vehicle's battery management system, allowing the battery to release more electricity than in the normal mode within a safe threshold, i.e., having a deeper "depth of discharge," thereby directly extending the vehicle's pure electric range on a single charge.

[0027] For users who have convenient access to charging, frequently charge their vehicles to full capacity, and have short commutes, they tend to prefer using the vehicle's pure electric mode. However, for users who have inconvenient access to charging and have long commutes, activating the MaxEV function can extend the pure electric range of the vehicle after a single charge during daily travel, thereby reducing the number of charging sessions and significantly reducing engine operating time and fuel consumption.

[0028] In conventional vehicle battery charging and discharging management, to prevent performance degradation or battery damage caused by battery state of charge (SOC) drift, the lower discharge limit of the battery in the MaxEV function is usually set to a relatively high threshold. When the battery SOC approaches this higher threshold, the battery actively limits its discharge power to prevent further SOC degradation, thereby maintaining the battery within a safe and stable operating range.

[0029] However, this protection strategy limits the available battery capacity, resulting in a corresponding reduction in the vehicle's pure electric range. Blindly lowering the lower threshold for the battery's state of charge when exiting the pure electric priority mode (MaxEV) would significantly impact battery health and increase vehicle safety risks.

[0030] Based on this, this embodiment provides a method for adjusting the depth of battery discharge, which can be used in a vehicle management terminal. The vehicle includes a battery management unit and an electronic control unit. Figure 1This is a flowchart of a battery discharge depth adjustment method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: In step S101, in response to the battery being in a charging state, the estimated state of charge of the battery is calibrated in real time so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery.

[0031] Step S102: When the voltage of a single cell of the battery reaches the full charge cutoff voltage, the real-time calibration of the estimated state of charge value ends and a full charge signal is generated.

[0032] Step S103: Perform a setting operation on the battery full charge signal to put the battery full charge signal in the set state, and adjust the battery discharge depth according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

[0033] The battery discharge depth adjustment method provided in this embodiment of the invention performs real-time calibration on the estimated state of charge (SOC) of the battery in response to the battery being in a charging state, ensuring that the calibrated SOC estimate is consistent with the actual SOC value. When the individual cell voltage of the battery reaches the full charge cutoff voltage, the real-time calibration of the SOC estimate ends, and a full charge signal is generated. A setting operation is performed on the full charge signal to set it to the set state, and the battery discharge depth is adjusted based on this set state. This embodiment combines high-precision real-time calibration of the estimated SOC value during the charging process, reducing the cumulative error between the estimated and actual values. Simultaneously, it introduces a flag bit after full charge correction, providing users with longer pure electric range while ensuring battery safety.

[0034] In step S101, in response to the battery being in a charging state, the estimated state of charge of the battery is calibrated in real time so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery.

[0035] The Battery Management System (BMS) is a control unit used to monitor and manage the core state of the battery, and can collect data on the battery's key operating parameters in real time.

[0036] In some embodiments of the present invention, during vehicle charging, the battery's individual cell voltage and charging current are continuously monitored by the Battery Management System (BMS). Specifically, the real-time individual cell voltage and charging current flowing into the battery are cyclically measured and acquired at fixed time intervals using sensors and sampling circuits configured within the BMS. When the individual cell voltage is detected to rise to a preset voltage threshold (e.g., 3.6V) and the charging current simultaneously drops to below a preset current threshold (e.g., 0.1A), it is determined that the battery has entered a stable electrochemical state suitable for State of Charge (SOC) calibration. At this time, the BMS initiates a SOC correction procedure to bring the estimated SOC value closer to the actual value. When the individual cell voltage reaches a preset full-charge cutoff voltage (e.g., 3.8V), the SOC correction procedure, which is synchronized with the charging process, ends. The specific steps are as follows: The system acquires the individual cell voltage and charging current of the battery when it is in the charging state. When the individual cell voltage is greater than the voltage reference value and the charging current is less than the current reference value, the system controls the battery management unit to perform real-time calibration on the estimated state of charge of the battery so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery.

[0037] This invention ensures the accuracy and reliability of calibration timing by setting clear start conditions and cutoff points during the charging process. Specifically, calibration is initiated when the individual cell voltage is greater than the voltage reference value and the charging current is lower than the current reference value during charging, and continues until the individual cell voltage reaches the full charge cutoff voltage. This process allows the battery management unit to actively synchronize the estimated state of charge (SOC) value with the actual SOC value of the battery, ultimately forcing the displayed SOC value to be set to 100% at full charge. This significantly improves the consistency between the vehicle's displayed charge level and the actual remaining battery energy, eliminates range anxiety for drivers caused by inaccurate SOC display values, and provides reliable reference data points for subsequent depth of battery discharge.

[0038] In some embodiments of the present invention, the state of charge (SOC) of the battery at the current individual cell voltage is estimated via the BMS during the charging process. Since the SOC estimate is based on instantaneous calculations obtained using dynamic estimation methods such as the ampere-hour integration method, it may contain long-term accumulated errors.

[0039] Furthermore, the inherent performance parameters of the battery are obtained, including a pre-measured open-circuit voltage to state of charge (OCC-SOC) table (presumably an OCV-SOC table) that matches the battery's chemical characteristics and is stored in the BMS. When the BMS detects that the charging current is below a specific charging threshold, it determines that the battery is in equilibrium, meaning that the current terminal voltage of the battery is infinitely close to the open-circuit voltage. Based on the current cell voltage and charging current value, the BMS consults the OCV-SOC table to determine the actual value of the battery's current state of charge. The actual value of the state of charge is compared with the estimated value, and the deviation between the two is calculated. This calculated deviation is used as the state of charge correction value.

[0040] During the charging phase, before the individual battery cell voltage reaches the full charge cutoff voltage, the calculated state of charge (SOC) correction value is used to iteratively update subsequent SOC estimates until the deviation between the estimated SOC and the actual SOC is eliminated, thus completing the real-time calibration of the battery SOC. Specifically, this includes the following steps: Obtain the estimated state of charge (SOC) value of the battery at the single cell voltage; obtain the battery's performance parameters, and determine the actual SOC value of the battery at the single cell voltage and charging current based on the performance parameters; calculate the corrected SOC value of the battery based on the actual SOC value and the estimated SOC value; if the single cell voltage has not reached the battery's full charge cutoff voltage, update the estimated SOC value of the battery based on the corrected SOC value until the estimated SOC value is consistent with the actual SOC value.

[0041] This invention utilizes the characteristic that the battery's terminal voltage approximates the open-circuit voltage during the charging phase to calculate the deviation between the estimated state of charge (SOC) and the actual SOC in real time. It then performs iterative corrections throughout the entire charging period, achieving a unified SOC between the estimated and actual values. This provides a precise data foundation for accurately determining the battery's full charge status and improves the accuracy of battery management.

[0042] For step S102, when the voltage of a single cell of the battery reaches the full charge cutoff voltage, the real-time calibration of the estimated state of charge value ends and a full charge signal of the battery is generated.

[0043] To ensure that the displayed battery level matches the actual battery status, once the individual battery cell voltage reaches the full charge cutoff voltage, the BMS immediately sends a full charge signal to the Electronic Control Module (ECM) and sets the displayed battery state of charge (SOC) value to 100%. This full charge signal serves as a full charge flag. This effectively eliminates the cumulative estimation error of the battery SOC and ensures the accuracy of the displayed battery level.

[0044] Specifically, when the battery management unit detects that the voltage of a single battery cell has reached the preset full charge cutoff voltage, it determines that the battery has entered a full charge state. The full charge cutoff voltage is the highest charging voltage threshold set based on the battery's chemical characteristics to ensure battery safety and lifespan. At this time, the charging of the battery and the calibration of the state of charge estimation value are ended, and a full charge signal is generated and sent to the electronic control unit.

[0045] The battery full charge signal is a digital flag indicating that the battery has reached full charge. To ensure that the battery level displayed on the human-machine interface is absolutely consistent with the actual internal charge state of the battery, the battery management unit (BMU) forces the state of charge (SOC) message field in its external communication to be set to 100% when issuing this signal. This eliminates potential cumulative errors in dynamic estimation and ultimately ensures the accuracy of the SOC value displayed on the vehicle's dashboard or central control platform at the moment of full charge, providing accurate SOC values ​​for subsequent energy consumption calculations and range predictions.

[0046] For step S103, a setting operation is performed on the battery full charge signal to put the battery full charge signal in a set state, and the battery discharge depth is adjusted according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

[0047] Specifically, the set operation is characterized as the operation of actively driving the battery full charge signal from an invalid / default state (such as logic '0' or low level) and locking it to an valid / predetermined state (such as logic '1' or high level).

[0048] The set state represents a stable and valid state after the battery full charge signal is driven by the set operation, such as a continuous logic '1' or high level state.

[0049] Before the electronic control unit sets the battery full charge signal, it is necessary to determine the first depth of discharge constraint to ensure that the battery's MaxEV function operates under suitable conditions.

[0050] The first depth of discharge constraint includes a time constraint, which is characterized by the requirement that the elapsed time from the last confirmed full charge event to the current time must be within a preset full charge time threshold. This threshold represents a configurable time window for the battery's full charge time, and this invention does not impose specific limitations on it. When determining whether the first depth of discharge constraint is met, the actual full charge time is first compared with the full charge time threshold in the time constraint. For example, if the last successful full charge calibration was completed on August 1, 2025, and the preset time window is 7 days, then any time between August 1, 2025, and August 7, 2025 (inclusive) is considered to meet this time constraint. However, if the current time is later than August 7, exceeding the full charge time threshold, it will be determined that the time constraint is not met.

[0051] Because the state of charge (SOC) of a battery gradually changes due to self-discharge during prolonged periods of inactivity or slight parameter drift during driving cycles, performing a deep discharge based on a fully charged reference with an outdated calibration time may lead to significant deviations in the SOC estimation due to reference distortion, potentially posing a risk. Therefore, this invention establishes a validity period for the calibrated battery by setting a time constraint. In cases where the reference data may become invalid, a new round of charging and full-charge calibration updates the battery's SOC, thereby continuously ensuring the accuracy of SOC estimation and battery safety.

[0052] The first depth of discharge constraint also includes a temperature constraint, which is characterized by the requirement that the current temperature of the battery must be higher than a preset battery temperature reference value. The temperature threshold is a parameter that can be adjusted according to the vehicle configuration and battery chemistry system, for example, it can be set to 10°C.

[0053] When a battery is in a low-temperature environment, the viscosity of its internal electrolyte increases significantly, leading to a decrease in the lithium-ion migration rate. Simultaneously, the solid-phase diffusion coefficient of the battery's negative electrode also decreases, making it difficult for lithium ions to intercalate and deintercalate within the active material. Since some charge cannot be released during discharge due to kinetic constraints, the effective usable capacity of the battery is instantly reduced. Furthermore, deep charge-discharge cycles at low temperatures accelerate battery aging, such as the potential deposition of lithium metal on the negative electrode surface. This irreversible consumption of active lithium reduces battery capacity.

[0054] Therefore, when the present invention determines that the battery may be in a performance-limited state due to low temperature, it actively limits the depth of discharge in MaxEV mode, thereby avoiding excessive battery discharge that may be caused by the reduction of battery available capacity under low temperature conditions. This ensures that the vehicle can still maintain a relatively good battery energy reserve in cold seasons and prevents potential damage to battery health caused by deep discharge under harsh operating conditions.

[0055] The first depth of discharge constraint also includes a health constraint. Health is the percentage of the battery's current usable capacity relative to its factory-rated capacity, used to quantify the degree of battery performance degradation. The health constraint is characterized by the battery's current health being higher than a preset health benchmark value. This benchmark value is a parameter that can be adjusted based on the battery's design life and the vehicle's durability goals; preferably, the health benchmark value can be set to 90%.

[0056] This invention, in its embodiments, determines the current health of a battery based on real-time monitoring and calculation of performance parameters (such as cumulative charge / discharge ampere-hours, internal resistance change rate, etc.), and then judges whether the calculated health value is greater than a preset battery health benchmark value. For example, the current battery health can be determined based on battery aging models, direct calculation methods for full-charge capacity calibration, and interpolation estimation methods based on the relationship between open-circuit voltage and capacity; this invention does not specifically limit the determination of these methods.

[0057] In one embodiment of the present invention, the historical operating data of the battery can be continuously collected and recorded by the sensors of the battery management unit. This historical operating data may include the battery's cumulative charge / discharge ampere-hours and the rate of change of the battery's internal resistance estimated using the AC impedance method or the DC pulse method. Then, the aforementioned real-time monitored performance parameters are used as input variables and input into the battery aging model. These parameters are combined with environmental and operational stress factors such as the battery's historical average operating temperature, temperature variation range, and charge / discharge rate distribution for comprehensive calculation to obtain the battery's health. The battery aging model is a degradation model based on historical data and electrochemical mechanisms. It compares the battery's current internal resistance value and cumulative charge / discharge ampere-hours with a preset benchmark aging curve established based on a large amount of experimental data from the battery model, or performs state estimation using embedded state estimation operators (such as the Kalman filter family) to output a quantified health level. The health level is typically expressed as a percentage representing the retention rate of the current actual usable capacity relative to the initial rated capacity. For example, when the model outputs that the current actual usable capacity of the battery has decayed to 90% of the initial rated capacity, the battery's health level is determined to be 90%.

[0058] In another embodiment of the invention, the battery management unit calculates the battery health by comparing the full charge capacity of the current cycle with the battery's initial rated capacity. For example, in each complete battery charging cycle, when the battery management unit determines that the battery has reached a full charge state (e.g., the cell voltage reaches the cutoff voltage and the charging current drops to the cutoff current), it calculates the total amount of electricity invested in this charge using the ampere-hour integration method. This amount of electricity is the current actual full charge capacity, and the current battery health is further calculated using the following formula: Health status = (Current full charge capacity / Initial rated capacity) × 100% In another embodiment of the present invention, the stable open-circuit voltage of the battery after resting is measured by the battery management unit. The voltage value corresponding to the current stable open-circuit voltage is compared with the OCV-SOC standard curve, which is stored in the battery management unit in advance and represents the battery's new state. Here, OCV represents the stable open-circuit voltage of the battery, and SOC represents the state of charge of the battery. Since battery aging will cause the entire OCV-SOC curve to deform, the degree of battery capacity loss can be determined by analyzing the difference between the current stable open-circuit voltage and the OCV-SOC standard curve at key points, or by using the voltage offset at a known SOC point (e.g., the 100% SOC point after the last full charge), thereby estimating the battery's health.

[0059] As the number of battery usage cycles increases, a series of irreversible chemical side reactions occur internally, such as the loss of active lithium ions, changes in electrode material structure, and electrolyte decomposition. These degradation phenomena lead to a continuous decrease in the battery's maximum usable capacity and an increase in its internal resistance. If deeper discharge (i.e., exceeding the MaxEV discharge depth) is performed after the battery's health has significantly deteriorated (e.g., below 90%), it will drastically accelerate the subsequent aging process of the battery and severely impair its remaining lifespan. Therefore, this invention introduces a health benchmark value to identify the operating conditions under which the battery has entered a significant aging stage. Under these conditions, deeper discharge operations are restricted, effectively preventing excessively harsh charge-discharge cycles after the battery's lifespan has deteriorated. This ensures that the battery's long-term lifespan is not negatively affected by the pursuit of short-term extended range, achieving a dynamic balance between range performance and battery lifespan.

[0060] In summary, the first depth of discharge constraint condition of this invention is composed of time constraint condition, temperature constraint condition, and health constraint condition. After the electronic control unit receives the battery full charge signal, it further determines the full charge time of the most recent full charge event based on the timestamp of the received full charge signal, and simultaneously collects the actual temperature data inside the battery, and compares the ratio of the battery's current maximum usable capacity to its initial rated capacity to calculate the battery's health. Based on this, the full charge time, battery temperature, and health are matched and verified against the preset first depth of discharge constraint condition. The first depth of discharge constraint condition includes three dimensions that must be met simultaneously: The first dimension is characterized by a time constraint condition: the time interval between the completion time of the full charge event and the current time is less than a set full charge time threshold to ensure the timeliness of the battery state of charge calibration data and avoid affecting the accuracy of the benchmark due to the drift of the battery open-circuit voltage characteristics caused by long-term vehicle idling. The second dimension is characterized by a temperature constraint condition: the current battery temperature is constrained to be higher than a set battery temperature benchmark value, ensuring the battery has normal energy output capability and cycle life by limiting low-temperature operating conditions. The third dimension is characterized by health constraints: the battery's current health is constrained to be higher than a set health benchmark value. Since the active material inside the battery decreases and impedance increases after numerous cycles, limiting further expansion of the depth of discharge effectively prevents accelerated capacity decay. Only when all three constraints are met simultaneously will a command to execute the battery full charge signal setting operation be sent to the electronic control unit, thereby improving energy utilization efficiency while ensuring the safety and durability of the battery system. The specific steps are as follows: The system determines the battery's full charge time and current temperature based on the battery's full charge signal, and determines the battery's current health status based on performance parameters. It then determines whether the battery meets the first depth of discharge constraint condition based on the full charge time, battery temperature, and health status. The first depth of discharge constraint condition is characterized by a full charge time less than a full charge time threshold, a battery temperature greater than a battery temperature reference value, and a health status greater than a battery health reference value. If the battery meets the first depth of discharge constraint condition, the system sets the battery's full charge signal.

[0061] After the instruction to set the battery full charge signal is executed, and the battery full charge signal is in the set state, the electronic control unit further monitors and judges the battery. Specifically, it detects the environmental parameters of the current environment of the vehicle through the vehicle sensors, mainly including the ambient temperature and the ambient altitude, and judges whether the second depth of discharge constraint condition is met based on the environmental parameters.

[0062] The second depth of discharge constraint includes an ambient temperature constraint, which is characterized by the ambient temperature of the current vehicle environment being within a safe temperature range. The safe temperature range is usually set to the normal temperature range, such as 10°C to 40°C, thereby eliminating the adverse effects of low or high temperature environments on battery performance and safety. Low temperatures will significantly reduce the battery's usable capacity and increase internal resistance, while high temperatures may exacerbate battery aging and the risk of thermal runaway.

[0063] The second discharge depth constraint also includes an environmental altitude constraint: the environmental altitude of the current vehicle's external environment is less than a preset altitude threshold. Considering that the thin air in high-altitude areas will affect the intake efficiency and heat dissipation performance of the engine in range-extended or hybrid vehicles, an altitude threshold is set to limit deep discharge in high-altitude areas, thereby ensuring the stable and safe operation of the vehicle's power system.

[0064] In summary, the electronic control unit will adjust the battery's discharge depth based on the previously set battery full charge signal only if the current environmental parameters simultaneously meet the aforementioned second discharge depth constraint. Specifically, when the user activates the MaxEV function, the battery discharge depth is lowered, thereby increasing the vehicle's pure electric range. Conversely, if any environmental parameter fails to meet the second discharge depth constraint, such as excessively low or high ambient temperature or altitude, this invention will restrict the adjustment of the battery discharge depth and continue to use the previously set, safer MaxEV exit threshold. This embodiment of the invention achieves an intelligent control strategy that balances improving battery range with ensuring safety and reliability under all operating conditions through a multi-constraint judgment mechanism. The specific steps are as follows: After setting the battery full charge signal, the environmental parameters of the vehicle's current environment are detected, and it is determined whether the environmental parameters meet the second depth of discharge constraint condition. The environmental parameters include ambient temperature and ambient altitude. The second depth of discharge constraint condition indicates that the ambient temperature is within a safe temperature range and the ambient altitude is less than the altitude threshold. If the environmental parameters meet the second depth of discharge constraint condition, the depth of discharge of the battery is adjusted according to the set state of the battery full charge signal.

[0065] Once the vehicle detects that the battery has undergone a full charge correction and that the battery temperature and health meet the first discharge depth constraint, the battery full charge signal sent by the BMS will remain in the set state for a certain period of time; that is, the set state of the battery full charge signal is considered valid. When the vehicle's ambient temperature is within a safe temperature range and the altitude is below the altitude threshold, the user can activate the vehicle's MaxEV function to further extend the battery discharge depth and increase the corresponding pure electric range.

[0066] Specifically, the electronic control unit (ECU) activates the vehicle's pure electric priority mode (i.e., MaxEV function). In this mode, it lowers the lower threshold of the battery's state of charge (SOC) when exiting pure electric priority mode, allowing the battery to release more stored energy to power the vehicle and improve its pure electric range. Simultaneously, since a drop in SOC to near a new, lower exit threshold may cause performance issues, the ECU simultaneously increases the battery's initial discharge power in pure electric priority mode when lowering the SOC threshold. Conversely, when pure electric priority mode (MaxEV function) is not activated, the ECU preemptively limits the battery's initial discharge power to prevent a rapid decline in SOC. The specific steps are as follows; When the battery full charge signal is in an active state, the battery's pure charge priority mode is activated. In pure charge priority mode, the battery's state of charge threshold when exiting pure charge priority mode is lowered, and the first discharge power of the battery when in pure charge priority mode is increased.

[0067] Because the hybrid discharge mode significantly limits battery discharge power when the battery is in a low state of charge, and the vehicle's power is primarily provided by the engine, a rapid switch in battery discharge power could lead to noticeable torque fluctuations, causing vehicle vibration. In another embodiment of this invention, to ensure smooth switching between driving modes, when the state of charge reaches a new lower threshold and it's time to exit pure electric priority mode, the electronic control unit performs battery power transition control. Specifically, it slowly adjusts the battery discharge power from the first discharge power in pure electric priority mode to the second discharge power in hybrid discharge mode. This effectively avoids vibrations or power surges that could cause driver discomfort due to rapid driving mode switching, ensuring a smooth driving experience. The specific steps are as follows: If the battery full charge signal is in an invalid state, or if the activation conditions for pure electric priority mode are not met, the battery's pure electric priority mode is turned off, and the battery's hybrid discharge mode is started. The battery's first discharge power in pure electric priority mode is adjusted to the battery's second discharge power in hybrid discharge mode.

[0068] In summary, when the battery full charge signal is in an invalid state, or when the conditions for activating the pure electric priority mode are not met, this embodiment of the invention will disable the pure electric priority mode and default to enabling the battery's hybrid discharge mode. In this conventional hybrid discharge mode, the battery's discharge power will be limited to a lower second discharge power level corresponding to the hybrid mode, prioritizing battery durability and vehicle operational safety.

[0069] This embodiment also provides a battery discharge depth adjustment device, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0070] This embodiment provides a battery discharge depth adjustment device, applied to a vehicle, the device as follows: Figure 2 As shown, it includes: The state of charge calibration module 201 is used to perform real-time calibration on the estimated state of charge of the battery in response to the battery being in a charging state, so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery.

[0071] The full charge signal transmitting module 202 is used to end the real-time calibration of the estimated state of charge value and generate a battery full charge signal when the voltage of a single cell of the battery reaches the full charge cutoff voltage.

[0072] The depth of discharge adjustment module 203 is used to perform a setting operation on the battery full charge signal, so that the battery full charge signal is in the set state, and adjust the depth of discharge of the battery according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

[0073] The vehicle includes a battery management unit and a state-of-charge calibration module 201, comprising: The charge data acquisition unit is used to acquire the individual cell voltage and charging current of the battery when it is in the charging state.

[0074] The state of charge (SOC) calibration unit is used to control the battery management unit to perform real-time calibration of the battery's estimated SOC value when the cell voltage is greater than the voltage reference value and the charging current is less than the current reference value, so that the calibrated estimated SOC value is consistent with the actual SOC value of the battery.

[0075] The state of charge calibration unit includes: The estimation value acquisition unit is used to acquire the estimated state of charge of the battery at the single cell voltage.

[0076] The actual value determination unit is used to obtain the battery's performance parameters and determine the actual state of charge (SOC) value corresponding to the battery's single-cell voltage and charging current based on the performance parameters.

[0077] The correction value calculation unit is used to calculate the battery's state of charge correction value based on the actual state of charge value and the estimated state of charge value.

[0078] If the voltage of a single cell does not reach the full charge cutoff voltage of the battery, the estimated state of charge of the battery is updated based on the state of charge correction value until the estimated state of charge is consistent with the actual state of charge.

[0079] The vehicle also includes an electronic control unit, and prior to the depth of discharge adjustment module 203, the device includes: The constraint acquisition module is used to determine the full charge time and current battery temperature of the battery based on the full charge signal, and to determine the current health of the battery based on performance parameters.

[0080] The constraint condition judgment module is used to determine whether the battery meets the first discharge depth constraint condition based on the full charge time, battery temperature, and battery health. The first discharge depth constraint condition is characterized by the full charge time being less than the full charge time threshold, the battery temperature being greater than the battery temperature reference value, and the battery health being greater than the battery health reference value.

[0081] The set execution module is used to control the electronic control unit to perform a set operation on the battery full charge signal when the battery meets the first discharge depth constraint condition.

[0082] Following the depth of discharge adjustment module 203, the device includes: The environmental parameter detection module is used to detect the environmental parameters of the current environment of the vehicle and determine whether the environmental parameters meet the second discharge depth constraint condition. The environmental parameters include ambient temperature and ambient altitude. The second discharge depth constraint condition indicates that the ambient temperature is within the safe temperature range and the ambient altitude is less than the altitude threshold.

[0083] The depth of discharge adjustment submodule is used to adjust the depth of discharge of the battery based on the setting state of the battery full charge signal, provided that the environmental parameters meet the second depth of discharge constraint.

[0084] Discharge depth adjustment module 203 includes: The first discharge depth adjustment unit is used to enable the battery's pure electric priority mode when the battery's full charge signal is in an effective state; in the pure electric priority mode, it lowers the battery's state of charge limit threshold when exiting the pure electric priority mode, and increases the first discharge power of the battery when it is in the pure electric priority function.

[0085] The second discharge depth adjustment unit is used to turn off the battery's pure electric priority mode and start the battery's hybrid discharge mode when the battery's full charge signal is in an invalid state or the start conditions for the pure electric priority mode are not met; and to adjust the first discharge power of the battery in the pure electric priority mode to the second discharge power of the battery in the hybrid discharge mode.

[0086] In this embodiment, the battery discharge depth adjustment device is presented in the form of a functional unit. Here, a unit refers to an ASIC circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above-mentioned functions.

[0087] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0088] This invention also provides a computer device having the above-described features. Figure 3 The device shown is for adjusting the depth of battery discharge.

[0089] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 3 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 3 Take a processor 10 as an example.

[0090] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0091] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0092] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device as shown by a landing page for an app. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, which can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0093] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0094] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0095] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0096] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for adjusting the depth of battery discharge, characterized in that, Applied to vehicles, the method includes: In response to the battery being in a charging state, the estimated state of charge of the battery is calibrated in real time to ensure that the calibrated estimated state of charge is consistent with the actual state of charge of the battery. When the voltage of a single cell of the battery reaches the full charge cutoff voltage, the real-time calibration of the estimated state of charge value ends and a full charge signal is generated. A setting operation is performed on the battery full charge signal to put the battery full charge signal in a set state, and the discharge depth of the battery is adjusted according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

2. The method according to claim 1, characterized in that, The vehicle includes a battery management unit; The real-time calibration of the battery's state of charge estimate in response to the battery being in a charging state includes: Obtain the individual cell voltage and charging current of the battery when it is in a charging state; When the voltage of the single cell is greater than the voltage reference value and the charging current is less than the current reference value, the battery management unit is controlled to perform real-time calibration on the estimated state of charge of the battery so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery.

3. The method according to claim 2, characterized in that, The control of the battery management unit to perform real-time calibration of the estimated state of charge of the battery includes: Obtain the estimated state of charge of the battery at the single cell voltage; Obtain the performance parameters of the battery, and determine the actual state of charge (SOC) value of the battery at the given single cell voltage and charging current based on the performance parameters. The state of charge correction value of the battery is calculated based on the actual state of charge value and the estimated state of charge value; If the voltage of a single cell does not reach the full charge cutoff voltage of the battery, the estimated state of charge of the battery is updated based on the state of charge correction value until the estimated state of charge is consistent with the actual state of charge.

4. The method according to claim 3, characterized in that, The vehicle also includes an electronic control unit; Before setting the battery full charge signal, the method includes: The full charge time and current battery temperature of the battery are determined based on the battery full charge signal, and the current health of the battery is determined based on the performance parameters. The battery is judged to meet the first depth of discharge constraint condition based on the full charge time, the battery temperature, and the battery health status; wherein, the first depth of discharge constraint condition is characterized by the full charge time being less than the full charge time threshold, the battery temperature being greater than the battery temperature reference value, and the battery health status being greater than the battery health reference value. When the battery meets the first depth of discharge constraint, the electronic control unit is controlled to set the battery full charge signal.

5. The method according to claim 1, characterized in that, After setting the battery full charge signal to the set state, the method further includes: The environmental parameters of the current environment of the vehicle are detected, and it is determined whether the environmental parameters meet the second depth of discharge constraint condition. The environmental parameters include ambient temperature and ambient altitude. The second depth of discharge constraint condition indicates that the ambient temperature is within a safe temperature range and the ambient altitude is less than an altitude threshold. When the environmental parameters meet the second discharge depth constraint, the discharge depth of the battery is adjusted according to the setting state of the battery full charge signal.

6. The method according to claim 1, characterized in that, Adjusting the depth of discharge of the battery based on the positioning state includes: When the battery full charge signal is in an active state, the pure electric priority mode of the battery is activated. In the pure electric priority mode, the state of charge limit threshold of the battery when exiting the pure electric priority mode is reduced, and the first discharge power of the battery when in the pure electric priority function is increased.

7. The method according to claim 6, characterized in that, The method further includes: When the battery full charge signal is in an invalid state, or when the activation conditions of the pure electric priority mode are not met, the pure electric priority mode of the battery is turned off, and the hybrid discharge mode of the battery is started. The first discharge power of the battery in the pure electric priority mode is adjusted to the second discharge power of the battery in the hybrid discharge mode.

8. A device for adjusting the depth of battery discharge, characterized in that, Applied to vehicles, the device includes: The state of charge calibration module is used to perform real-time calibration on the estimated state of charge of the battery in response to the battery being in a charging state, so that the calibrated estimated state of charge is consistent with the actual state of charge of the battery. The full charge signal transmitting module is used to end the real-time calibration of the estimated state of charge value and generate a battery full charge signal when the voltage of a single cell of the battery reaches the full charge cutoff voltage. The depth of discharge adjustment module is used to perform a setting operation on the battery full charge signal, so that the battery full charge signal is in a set state, and adjust the depth of discharge of the battery according to the set state. The setting operation is characterized by adjusting the battery full charge signal from a low level to a high level, and the set state is characterized by the high level state of the battery full charge signal.

9. A computer device, characterized in that, include: A memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method of any one of claims 1 to 7.

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