Vehicle-mounted battery system health assessment method and vehicle

Abstract

The invention discloses a health assessment method of a vehicle-mounted battery system and a vehicle. The method comprises the following steps: under the condition of determining that a charge state value of a battery system meets a preset discharge condition, discharging the battery system until the voltage of a single battery of the battery system meets a preset calibration condition; calibrating the state-of-charge value of the battery system based on the relation curve of the state-of-charge value and the open-circuit voltage and the open-circuit voltage of the battery system; charging the calibrated battery system until the state-of-charge value of the battery system meets a preset full charge condition; and evaluating the health state of the battery system based on the original capacity and the actual charging capacity of the battery system, and generating a health evaluation result of the battery system. According to the invention, the technical problems of difficult long-term running vehicle battery state capacity test and insufficient test precision in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle protection, and in particular, to a method for health assessment of an in-vehicle battery system and a vehicle. Background Art

[0002] With the development of green clean energy power, lithium batteries, as power storage carriers, have been widely used. At the same time, with the development of technology, the service life of batteries is also getting higher and higher. How to reasonably monitor and detect the remaining capacity of batteries during the warranty period and judge the health status of batteries has become a key factor.

[0003] In the prior art, for an in-vehicle battery system, it is difficult to test the battery state capacity during long-term operation of the vehicle and the test accuracy is insufficient, which has become a key problem at present. In view of the above problems, no effective solution has been proposed yet. Summary of the Invention

[0004] Embodiments of the present invention provide a method for health assessment of an in-vehicle battery system and a vehicle, so as to at least solve the technical problems of difficult testing of the battery state capacity during long-term operation of the vehicle and insufficient test accuracy in related technologies.

[0005] According to one aspect of the embodiments of the present invention, a method for health assessment of an in-vehicle battery system is provided, including: discharging the battery system until the voltage of a single battery in the battery system meets a preset calibration condition when it is determined that the state of charge value of the battery system meets a preset discharge condition; calibrating the state of charge value of the battery system based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system; charging the calibrated battery system until the state of charge value of the battery system meets a preset full charge condition; and evaluating the health status of the battery system based on the original capacity and the actual charge capacity of the battery system, and generating a health assessment result of the battery system.

[0006] Optionally, discharging the battery system until the voltage of a single battery in the battery system meets a preset calibration condition includes: discharging the battery system until at least one of the voltages of multiple single batteries in the battery system is less than or equal to a preset single battery voltage value, and the voltages of all single batteries are greater than or equal to the single battery protection voltage, where the preset single battery voltage value is greater than the single battery protection voltage; obtaining the voltage difference between single batteries in the battery system, where the voltage difference between single batteries is the voltage difference between any two single batteries; and determining that the voltage of a single battery in the battery system meets the preset calibration condition when it is determined that the voltage difference between single batteries meets a preset voltage difference condition.

[0007] Optionally, after obtaining the voltage difference between single batteries in the battery system, the method further includes: adjusting the voltage difference between single batteries in the battery system by using an equalizing discharge strategy when it is determined that the voltage difference between single batteries does not meet the preset voltage difference condition.

[0008] Optionally, after adjusting the voltage difference between individual cells of the battery system using an equalizing discharge strategy, the method further includes: when the equalizing discharge duration meets the preset duration condition and the voltage difference between individual cells does not meet the preset voltage difference condition, stopping the discharge and generating a status anomaly prompt for the battery system, where the status anomaly prompt is at least used to prompt battery replacement; wherein, the equalizing discharge duration is used to represent the duration of adjusting the voltage difference between individual cells of the battery system using the equalizing discharge strategy.

[0009] Optionally, when it is determined that the state of charge value of the battery system meets the preset discharge condition, discharging the battery system includes: when it is determined that the state of charge value of the battery system is less than or equal to the first preset value, discharging the battery system.

[0010] Optionally, charging the calibrated battery system until the state of charge value of the battery system meets the preset full charge condition includes: charging the battery system until the state of charge value of the battery system is equal to the full charge state value.

[0011] Optionally, based on the original capacity and the actual charge capacity of the battery system, evaluating the health state of the battery system and generating a battery system health assessment result includes: determining the remaining capacity ratio of the battery system based on the original capacity and the actual charge capacity of the battery system; evaluating the health state of the battery system based on the remaining capacity ratio and generating a battery system health assessment result.

[0012] Optionally, the method further includes: determining the remaining life of the battery system based on the battery system health assessment result and the battery life prediction model.

[0013] Optionally, the method further includes: generating a battery maintenance strategy based on the remaining life of the battery system and the battery system health assessment result; wherein, the battery maintenance strategy at least includes one of the following: a battery replacement strategy, a battery usage mode adjustment strategy.

[0014] According to another aspect of the embodiments of the present invention, a vehicle is further provided, the vehicle having an in-vehicle battery system, and the in-vehicle battery system is health-evaluated using the above-mentioned health assessment method for the in-vehicle battery system.

[0015] In an embodiment of the present invention, when it is determined that the state of charge value of the battery system meets the preset discharge condition, the battery system is discharged until the voltage of the individual battery of the battery system meets the preset calibration condition; based on the relationship curve between the state of charge value and the open circuit voltage and the open circuit voltage of the battery system, the state of charge value of the battery system is calibrated; the calibrated battery system is charged until the state of charge value of the battery system meets the preset full charge condition; based on the original capacity and the actual charging capacity of the battery system, the health state of the battery system is evaluated, and a battery system health evaluation result is generated. The technical solution of this embodiment performs state of charge value detection, discharge, state of charge calibration, and charging during the actual operation of the vehicle, achieving the purpose of accurately evaluating the health state of the battery system under the actual operating conditions of the vehicle, realizing the technical effects of efficient and low-cost battery capacity detection and SOC calibration, and thus solving the technical problems of difficult battery state capacity testing and insufficient testing accuracy for long-term operating vehicles in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0017] Figure 1 is a hardware structure block diagram of an electronic device of a vehicle according to one embodiment of the present invention;

[0018] Figure 2 is a flowchart of a method for health evaluation of an in-vehicle battery system according to one optional embodiment of the present invention;

[0019] Figure 3 is a flowchart of a method for health evaluation of an in-vehicle battery system according to one optional embodiment of the present invention;

[0020] Figure 4 is a structure block diagram of a device for health evaluation of an in-vehicle battery system according to one optional embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to enable those skilled in the art of the present technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily limit to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0023] According to one embodiment of the present invention, an embodiment of a method for health assessment of an in-vehicle battery system is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that here.

[0024] This method embodiment can be executed in an electronic device or a similar computing device that includes a memory and a processor in a vehicle. Taking running on the electronic device of a vehicle as an example, as Figure 1 shown, the electronic device of the vehicle can include one or more processors 102 (the processor can include but is not limited to processing devices such as a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microprocessor (MCU), a field programmable gate array (FPGA), a neural network processor (NPU), a tensor processor (TPU), an artificial intelligence (AI) type processor, etc.) and a memory 104 for storing data. Optionally, the above-mentioned electronic device of the vehicle can also include a transmission device 106 for communication functions, an input / output device 108, and a display 110. Those of ordinary skill in the art can understand that Figure 1 the structure shown is only schematic and does not limit the structure of the above-mentioned electronic device of the vehicle. For example, the electronic device of the vehicle can also include more or fewer components than those described in the above structure, or have a configuration different from that described in the above structure.

[0025] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the health assessment method of the vehicle-mounted battery system in the embodiments of the present invention. The processor 102 executes various functional applications and data processing by running the computer programs stored in the memory 104, that is, implements the above-mentioned health assessment method of the vehicle-mounted battery system. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some instances, the memory 104 may further include a memory remotely disposed relative to the processor 102, and these remote memories can be connected to the mobile terminal through a network. Examples of the above network include but are not limited to the Internet, intranet, local area network, mobile communication network, and combinations thereof.

[0026] The transmission device 106 is used to receive or send data via a network. Specific examples of the above network may include a wireless network provided by a communication provider of the mobile terminal. In one instance, the transmission device 106 includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices through a base station and thus communicate with the Internet. In one instance, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0027] The display 110 can be, for example, a touch-screen liquid crystal display (LCD). The liquid crystal display enables the user to interact with the user interface of the mobile terminal. In some embodiments, the above mobile terminal has a graphical user interface (GUI), and the user can perform human-computer interaction with the GUI through finger contacts and / or gestures on the touch-sensitive surface. The human-computer interaction function here optionally includes the following interactions: creating web pages, drawing, word processing, creating electronic documents, games, video conferencing, instant messaging, sending and receiving emails, call interfaces, playing digital videos, playing digital music, and / or web browsing, etc. The executable instructions for performing the above human-computer interaction functions are configured / stored in a computer program product or readable storage medium executable by one or more processors.

[0028] In this embodiment, a health assessment method for a vehicle-mounted battery system of an electronic device running on the above vehicle is provided. Figure 2 It is a flowchart of the health assessment method for a vehicle-mounted battery system according to an embodiment of the present invention, as Figure 2 shown, and this process includes the following steps:

[0029] Step S21: When it is determined that the state of charge value of the battery system meets the preset discharge condition, the battery system is discharged until the voltage of the individual battery in the battery system meets the preset calibration condition.

[0030] Among them, the preset discharge condition is set to conduct a deep discharge test when the SOC of the battery system is relatively low, so as to more accurately evaluate the capacity and health status of the battery system. Discharging the battery system until the voltage of the individual battery in the battery system meets the preset calibration condition means discharging the battery system to a specific low voltage value, so that the battery system is in a state where accurate SOC calibration can be performed, thereby reducing the test capacity deviation. It should be noted that the battery system in this application is an in-vehicle battery system, and the determination that the state of charge value of the battery system meets the preset discharge condition is based on the data collected according to the actual operating conditions of the vehicle. That is to say, the battery health status evaluation in this application is carried out in the actual operating environment of the vehicle.

[0031] It should be noted that in the embodiments of this application, the battery cells in the in-vehicle battery system can be any one of square shell battery cells and cylindrical battery cells.

[0032] Step S22: Calibrate the state of charge value of the battery system based on the relationship curve between the state of charge value and the open circuit voltage and the open circuit voltage of the battery system.

[0033] In step S22, the relationship curve between the state of charge value and the open circuit voltage (hereinafter referred to as the SOC-OCV curve) can be a pre-set curve. This curve reflects the open circuit voltage of the battery under different states of charge and is an important tool for battery state evaluation. Based on the SOC-OCV curve and the read open circuit voltage of the battery system, the current state of charge value of the battery system can be obtained. The purpose of calibrating the SOC is to correct the SOC measurement error caused by factors such as voltage difference and temperature change to ensure the accuracy of the SOC.

[0034] For example, according to the SOC-OCV curve, when the SOC is 100%, the OCV is 4.2V; when the SOC drops to 0%, the OCV drops to about 2.5V. The open circuit voltage of the battery system (i.e., OCV, Open Circuit Voltage) is an instantaneously measured value. Suppose the measured OCV value is 3.8V. According to the OCV-SOC curve, the corresponding SOC value when the OCV is 3.8V can be found. If the OCV-SOC curve shows that 3.8V corresponds to an SOC of 60%, while the SOC originally estimated by the BMS (Battery Management System) is 65%, then there is a 5% deviation. At this time, the SOC value in the BMS can be adjusted to 60% to calibrate the SOC.

[0035] Step S23: Charge the calibrated battery system until the state of charge (SOC) value of the battery system meets the preset full charge condition;

[0036] In step S23, after the SOC calibration is completed, the battery system is charged until the SOC reaches the full charge condition, which usually means the SOC reaches 100%. This process is to collect the actual charging capacity data of the battery system to evaluate the total capacity and charging efficiency of the battery. Specifically, an additional charger can be used to charge the battery system.

[0037] Step S24: Based on the original capacity and the actual charging capacity of the battery system, evaluate the health state of the battery system and generate a battery system health assessment result.

[0038] In step S24, according to the original capacity of the battery system and the actual charging capacity determined in this test, the remaining capacity percentage of the battery system can be calculated, and then the health state of the battery can be evaluated. If the actual charging capacity is significantly lower than the original capacity, it indicates that the health condition of the battery may be poor, and there may be problems such as capacity attenuation and internal short circuit. This assessment result helps to subsequently determine whether the battery meets the warranty conditions, whether it needs repair or replacement, and estimate the remaining service life of the battery, so as to provide timely and reliable battery repair suggestions to the user and improve the battery usage experience and vehicle application experience.

[0039] Through the above steps, when it is determined that the state of charge value of the battery system meets the preset discharge condition, the battery system is discharged until the cell voltage of the battery system meets the preset calibration condition; based on the relationship curve between the state of charge value and the open circuit voltage and the open circuit voltage of the battery system, the state of charge value of the battery system is calibrated; the calibrated battery system is charged until the state of charge value of the battery system meets the preset full charge condition; based on the original capacity and the actual charging capacity of the battery system, the health state of the battery system is evaluated and a battery system health assessment result is generated. The technical solution of this embodiment performs state of charge value detection, discharge, state of charge calibration, and charging during the actual operation of the vehicle, achieving the purpose of accurately evaluating the health state of the battery system under the actual operating conditions of the vehicle, realizing the technical effects of efficient and low-cost battery capacity detection and SOC calibration, and thus solving the technical problems of difficult battery state capacity testing and insufficient testing accuracy for long-term operating vehicles in related technologies.

[0040] Optionally, in step S21, discharging the battery system until the cell voltage of the battery system meets the preset calibration condition includes the following implementation steps:

[0041] Step S221: Discharge the battery system until at least one of the multiple single-cell voltages of the battery system reaches a preset single-cell voltage value, and the single-cell voltages are all greater than or equal to the single-cell protection voltage, where the preset single-cell voltage value is greater than the single-cell protection voltage.

[0042] In step S221, the single-cell protection voltage is a safety threshold set in the battery design. Below this voltage value, the battery may be permanently damaged. Therefore, discharging to the preset single-cell voltage value, and the preset single-cell voltage value being greater than the single-cell protection voltage, can ensure that irreversible damage will not be caused to the battery during discharge. This is applicable to the state recovery and calibration of the battery system after long-term idle or deep discharge. Also, the difference between the preset single-cell voltage value and the single-cell protection voltage should not be too large to ensure that the battery system is discharged to a suitable calibration base state. For example, when the single-cell protection voltage is 2.4V, the preset single-cell voltage value is 2.5V; when the single-cell protection voltage is 2.7V, the preset single-cell voltage value is 2.8V.

[0043] Step S222: Obtain the voltage difference between single cells of the battery system, where the voltage difference between single cells is the voltage difference between any two single cells.

[0044] In step S222, the voltage difference between single cells refers to the difference between the voltages of any two single cells in the battery system, which reflects the consistency of the batteries in the battery pack. Inconsistent single-cell voltages may lead to a decline in the overall performance of the battery pack, and even affect the service life and safety of the battery.

[0045] Step S223: When it is determined that the voltage difference between single cells meets the preset voltage difference condition, determine that the single-cell voltages of the battery system meet the preset calibration condition.

[0046] In step S223, check whether the voltage differences of all single cells reach the preset allowable range (i.e., the preset voltage difference condition). If the voltage differences of all single cells meet this condition, that is, the voltage differences are within a reasonable range, then the battery system is considered to meet the preset calibration condition and can enter the next step - the SOC calibration stage. For example, the preset calibration condition can be that the voltage difference between single cells is less than or equal to 10 mV, or the voltage difference between single cells is less than or equal to 30 mV.

[0047] Through steps S221 - S223, by the process of discharging to the protection voltage, measuring the cell voltage difference, and ensuring that it meets the preset voltage difference condition, the voltage consistency inside the battery system before SOC calibration is ensured, which is the basis for evaluating the battery health status and remaining capacity. The setting of the equalization and protection voltage conditions helps prevent battery damage, while ensuring the accuracy and reliability of the calibration process, providing a solid foundation for subsequent SOC calibration and capacity assessment, and solving the problem of battery state assessment during long - term operation of vehicles.

[0048] Optionally, after obtaining the cell voltage difference of the battery system in step S222, the method further includes:

[0049] Step S224, in the case where it is determined that the cell voltage difference does not meet the preset voltage difference condition, an equalization discharge strategy is adopted to adjust the cell voltage difference of the battery system.

[0050] In step S224, when the cell voltage difference exceeds the allowable range (i.e., does not meet the preset voltage difference condition), an equalization discharge strategy is adopted to solve this problem. Specifically, the system continues to discharge, and during the discharge process, through an active equalization circuit (such as supercapacitor equalization, energy - conversion - type equalization, etc.), electrical energy is transferred from the high - voltage cells to the low - voltage cells until the voltage difference of all cells meets the preset voltage difference condition. The cell voltage difference is adjusted within the preset voltage difference condition through the equalization discharge strategy, that is, the voltage difference is within the allowable range, and the test process will continue, including steps such as SOC calibration, charging to full charge state, recording the charging power and capacity, calculating the remaining capacity percentage, etc., to complete the overall assessment of the health status of the on - vehicle battery system.

[0051] Through step S224, the equalization discharge strategy can effectively adjust the voltage difference inside the battery system, help restore the charge balance inside the battery system, improve the consistency of the battery cells, thereby improving the overall performance and service life of the battery system, and is applicable to the equalization state adjustment of the battery system during charging or discharging. At the same time, the equalization discharge strategy effectively solves the problem of test capacity deviation caused by the cumulative cell voltage difference during the operation of the battery system, ensuring that the SOC calibration process is carried out under the condition of good voltage consistency of all cells, thereby improving the accuracy and reliability of the health assessment.

[0052] Optionally, after adopting the equalization discharge strategy to adjust the cell voltage difference of the battery system in step S224, the method further includes:

[0053] Step S225, when the equalized discharge duration meets the preset duration condition and the cell voltage difference does not meet the preset voltage difference condition, stop discharging and generate a status anomaly prompt for the battery system. The status anomaly prompt is at least used to prompt battery replacement; wherein, the equalized discharge duration is used to represent the duration of adjusting the cell voltage difference of the battery system using the equalized discharge strategy.

[0054] In step S225, the preset duration condition refers to the time upper limit set during the equalized discharge process, usually several hours (such as 8 hours). If after reaching this preset duration, the cell voltage difference still fails to drop within the preset voltage difference condition range, that is, the voltage difference problem is not effectively solved, this indicates that one or some of the batteries in the battery system may have reached an irrecoverable abnormal state. At this time, stop discharging and generate a prompt message for the abnormal status of the battery system. This prompt message at least includes a suggestion for battery replacement, indicating that the current battery system may no longer be suitable for continued use due to severe faults or aging of some battery cells, in order to ensure the operation safety and performance of the vehicle. The status anomaly prompt can timely report potential problems of the battery system to the driver or maintenance personnel. Specifically, the status anomaly prompt can adopt various methods such as voice prompt, pop-up prompt on the user terminal (such as mobile phone, tablet), vehicle center console interface prompt, and light prompt.

[0055] Through step S225, if the equalized discharge strategy fails to improve the cell voltage difference within the preset duration, generate a prompt message to remind the abnormal status of the battery system and suggest battery replacement, avoiding a decline in vehicle performance or safety risks caused by battery faults. By timely detecting and reporting serious voltage inconsistency problems during the test process, it prompts users to take necessary maintenance or replacement measures, thereby ensuring the long-term stability of the battery system and the safe operation of the vehicle. At the same time, this step also helps to extend the service life of the battery system, reduce early scrapping caused by improper battery maintenance, and improve the economic benefits of the vehicle.

[0056] Optionally, in step S21, when it is determined that the state of charge value of the battery system meets the preset discharge condition, discharge the battery system, including:

[0057] Step S211, when it is determined that the state of charge value of the battery system is less than or equal to the first preset value, discharge the battery system.

[0058] In step S211, the selection of the first preset value is based on considerations of battery safety and performance. Usually, when the battery SOC is lower than 20%, it means that the battery pack is in a low state of charge. At this time, performing a deep discharge test can more accurately evaluate the battery capacity and health status, while avoiding the risk of over-discharging the battery. Optionally, the first preset value can also be set to 15%.

[0059] Through step S211, by setting reasonable discharge conditions, it is possible to avoid performing discharge calibration when the state of charge of the battery system is relatively high, reduce energy waste, and it is applicable to the maintenance and calibration of the battery system in a low state of charge.

[0060] Optionally, in step S23, the calibrated battery system is charged until the state of charge value of the battery system meets the preset full charge condition, including:

[0061] Step S231, charge the battery system until the state of charge value of the battery system is equal to the full charge state value.

[0062] Through step S231, the battery system is charged to the full charge state, that is, the SOC reaches 100%. During the process of charging the SOC of the battery system from the low charge state to the full charge state, the charging power and capacity can be recorded, and then the remaining capacity percentage of the battery system within the test cycle can be calculated, providing important data for the assessment of the battery health state.

[0063] Optionally, in step S24, based on the original capacity and the actual charging capacity of the battery system, the health state of the battery system is evaluated to generate a battery system health assessment result, including:

[0064] Step S241, based on the original capacity and the actual charging capacity of the battery system, determine the remaining capacity ratio of the battery system;

[0065] In step S241, the remaining capacity ratio can be calculated by the following formula: remaining capacity ratio = actual charging capacity / original capacity. This ratio intuitively reflects the comparison between the current actual capacity and the original capacity of the battery system and is a key indicator for evaluating the battery health state.

[0066] Step S242, based on the remaining capacity ratio, evaluate the health state of the battery system to generate a battery system health assessment result.

[0067] In step S242, generally, during the use of the battery system, due to the influence of factors such as natural aging, overcharging and over-discharging, and temperature changes, its actual capacity will gradually decrease. When the remaining capacity ratio is lower than a certain threshold, it indicates that the health state of the battery system is not good and may not be able to meet the normal operation requirements of the vehicle. On the contrary, if the remaining capacity ratio is relatively high, it means that the battery system is in good condition and still has a high storage capacity. Based on the remaining capacity ratio, a battery system health assessment result can be generated, which can include but is not limited to key information such as the current health state of the battery system, whether it meets the warranty conditions, and the expected remaining service life, providing a scientific basis for vehicle maintenance, battery management, and subsequent usage decisions.

[0068] By steps S241 - S242, calculating the remaining capacity ratio can intuitively reflect the attenuation degree of the battery system, providing a scientific basis for vehicle maintenance and battery replacement, and is applicable to the performance monitoring and evaluation of the battery system during different usage cycles. Based on the remaining capacity ratio, the health status of the battery system is evaluated to generate a battery system health assessment result. Through the health status assessment, it can provide dual guarantees of safety and economy for the operation of the vehicle, and is applicable to the performance monitoring and maintenance of the battery system during daily use.

[0069] Optionally, the method further includes:

[0070] Step S25, determining the remaining life of the battery system based on the battery system health assessment result and the battery life prediction model.

[0071] In step S25, the battery life prediction model is a mathematical model based on historical data and battery characteristic parameters, used to predict the remaining service life of the battery under specific usage conditions. The model usually considers factors such as the number of charge and discharge cycles, depth, temperature, and change in state of charge of the battery. By simulating and analyzing the influence of these factors on the battery performance, it predicts the remaining life of the battery. In this embodiment, the battery life prediction model takes the remaining capacity ratio in the health assessment result as one of the input parameters, and combines the running time and usage of the vehicle to conduct life prediction.

[0072] In an exemplary embodiment of the present application, the remaining capacity of the battery system can be determined by using polynomial fitting curves after multiple tests on the battery system. For example:

[0073] y = ax 3 + bx 2 + cx + d;

[0074] Wherein, x represents the running time of the battery system (in years), a, b, c, and d are constants of polynomial simulation, and y represents the remaining capacity of the battery system (in percentage). By fitting the remaining capacity ratios at different running time points, the model can predict that at a certain future time point, the remaining capacity of the battery system will drop below a certain threshold, thereby determining the remaining life of the battery system. It should be noted that the numerical fitting of a, b, c, and d is based on multiple capacity tests on the battery system. To make the numerical results of a, b, c, and d more accurate, the battery system should be subjected to no less than four capacity tests.

[0075] The remaining capacity ratio and the total vehicle operation time in the health assessment results are input into the battery life prediction model, and the model will output a predicted remaining life result, usually in years. The determination of this remaining life is of great significance for vehicle maintenance and battery management. For example, if the prediction result indicates that the remaining capacity of the battery system will drop to an unacceptable level within the next 3 years, then users and maintenance personnel can plan ahead for battery replacement or cascaded use to avoid a decline in vehicle performance or safety risks caused by battery failure.

[0076] Through step S25, based on the detailed assessment of the current battery state and the battery life prediction model, a scientific prediction of the future performance and remaining life of the battery system is provided. This function is of great value for the long-term operation planning of the vehicle and battery asset management, helps improve operational efficiency and user satisfaction, and at the same time reduces the uncertainty risk brought by battery failure.

[0077] Optionally, the method further includes:

[0078] Step S26, generating a battery maintenance strategy based on the remaining life of the battery system and the battery system health assessment results; wherein, the battery maintenance strategy includes at least one of the following: a battery replacement strategy, a battery usage mode adjustment strategy.

[0079] Optionally, in step S26, the battery replacement strategy is applied as follows: If the health assessment result and the remaining life prediction show that the battery system is about to or has exceeded its effective service life, or the battery health state has severely declined and cannot meet the normal operation requirements of the vehicle, then the generated battery replacement strategy will recommend battery replacement. This strategy ensures the safety and performance of the vehicle and avoids accidents and downtime caused by battery failure.

[0080] Optionally, in step S26, the battery usage mode adjustment strategy is applied as follows: For a battery system with a relatively long remaining life but a slightly declined health state, the battery usage mode adjustment strategy recommends adjusting the battery usage mode, such as restricting the charge and discharge depth of the battery, optimizing the battery temperature management, adjusting the driving mode of the vehicle, etc., to slow down the battery aging speed and extend its service life.

[0081] Through step S26, the battery maintenance strategy can avoid performance problems of the battery system without warning. For example, if the battery replacement strategy is triggered, maintenance personnel can arrange the time and process of battery replacement in advance to ensure the smooth progress of the replacement process and reduce the impact on vehicle operation. The battery usage mode adjustment strategy needs to monitor and control the battery usage conditions through the battery management system (BMS) to ensure that the battery works in the best operating state and extend the service life of the battery.

[0082] Figure 3It is a schematic diagram of a method for health assessment of an in-vehicle battery system according to a preferred embodiment of the present invention.

[0083] As Figure 3 shown, the method includes the following steps:

[0084] S10, the vehicle runs until the SOC is lower than 20%;

[0085] Among them, the vehicle runs according to the actual daily operation, which is close to the actual working conditions of the vehicle and is conducive to predicting the subsequent usage status of the vehicle.

[0086] S20, use a discharge device with an equalization function to discharge the vehicle battery to the single-cell protection voltage value;

[0087] Among them, the discharge of the battery system is carried out during the actual operation of the vehicle, and the discharge working conditions are consistent with the actual use, which can fully reflect the actual available capacity of the battery system and reduce the test deviation.

[0088] S30, read the single-cell voltage value of the system, confirm whether the voltage difference between single cells reaches the allowable value. If it reaches, go to S40; otherwise, go to S310;

[0089] S310, determine whether the equalization time exceeds the allowable value. If not, go to S330; if it exceeds, go to S320;

[0090] S320, stop the test and replace the battery cell;

[0091] S330, continue to equalize until the voltage difference reaches the allowable value, and record the equalization time;

[0092] Among them, a low-voltage discharge process with equalization is set at the end of the discharge. Through this process, the test capacity deviation caused by the influence of the voltage difference between single cells in the battery system is eliminated. The equalization in the equalization discharge process is an active equalization, which better ensures the consistency of the single-cell voltage of the battery system while reducing the energy loss during the equalization process. An auxiliary identification process is set in the equalization. When the voltage difference between single cells does not meet the required value within the specified equalization time (such as within 8 hours), the in-vehicle battery system is identified as an abnormal system.

[0093] S40, SOC calibration, calibrate the SOC value according to the SOC-OCV curve;

[0094] Among them, the battery system is calibrated after the equalization and low-voltage discharge processes. During calibration, the voltage difference is within a reasonable range, ensuring the accuracy of the SOC.

[0095] S50, connect the charger to charge until the SOC reaches 100%;

[0096] S60, record the charging power and capacity;

[0097] S70. Calculate the remaining capacity percentage: η = measured capacity / standard capacity, where the measured capacity is the actual capacity of the battery determined in this test.

[0098] The above steps can be set to be performed at regular intervals, that is, by detecting at regular intervals and recording the remaining capacity of the battery. Combining the total running time of the vehicle during the test period, the capacity of the battery system is tested for four consecutive time periods. Based on the four sets of test data obtained (including at least the measured capacity and the remaining capacity percentage obtained from four tests), the following fitting polynomial can be calculated:

[0099] y = ax 3 + bx 2 + cx + d;

[0100] In the formula: x is the running time of the battery system, in years; a, b, c, d are constants simulated by the polynomial; y is the remaining capacity of the battery system, in %.

[0101] Substitute the coefficients a, b, c, d into the polynomial to obtain the remaining capacity y of the battery system. Based on the remaining capacity y and the remaining SOC allowed by the warranty, it can be determined whether the battery system meets the warranty requirements. At the same time, through estimation, it can also be confirmed whether the battery meets the requirements for cascade use.

[0102] Applying the technical solution in this embodiment, data is collected according to the actual operating conditions of the vehicle during the test. At the same time, the influence of the cumulative problem of the single - cell voltage difference caused during the long - term use of the vehicle is solved. In the design of the test process, the SOC of the battery system during vehicle operation is first reached, and then the principle of balancing the voltage difference is followed to process the influence of the voltage difference. This solution accurately estimates the service life of the in - vehicle battery system according to the actual operating conditions of the vehicle.

[0103] The technical solution of this embodiment has the following beneficial effects:

[0104] 1) Test the remaining capacity of the battery system along with the vehicle to evaluate the health status of the battery system. The test process does not require laboratory testing, reducing the work intensity and testing costs;

[0105] 2) Determine the consistency of the system battery cells through capacity detection, synchronously detect the deviation of the SOC, and calibrate it in a timely manner, effectively balancing the single - cell voltage difference and correcting the SOC;

[0106] 3) The test result deviation is small, which can better reflect the actual state of the battery system, solving the problems of battery state capacity testing and test accuracy for long - running vehicles.

[0107] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases, the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention.

[0108] In this embodiment, a health assessment device for a vehicle-mounted battery system is also provided. This device is used to implement the above embodiments and preferred implementation methods, and those that have been described will not be repeated. As used hereinafter, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0109] Figure 4 is a structural block diagram of a health assessment device for a vehicle-mounted battery system according to one embodiment of the present invention. As Figure 4 shown, the device includes: a discharge module 40, which is used to discharge the battery system until the single-cell voltage of the battery system meets the preset calibration condition when it is determined that the state of charge value of the battery system meets the preset discharge condition; a calibration module 42, which is used to calibrate the state of charge value of the battery system based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system; a charging module 44, which is used to charge the calibrated battery system until the state of charge value of the battery system meets the preset full-charge condition; an evaluation module 46, which is used to evaluate the health state of the battery system based on the original capacity and the actual charging capacity of the battery system and generate a health assessment result of the battery system.

[0110] Through the above device, when it is determined that the state of charge value of the battery system meets the preset discharge condition, the battery system is discharged until the single-cell voltage of the battery system meets the preset calibration condition; based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system, the state of charge value of the battery system is calibrated; the calibrated battery system is charged until the state of charge value of the battery system meets the preset full-charge condition; based on the original capacity and the actual charging capacity of the battery system, the health state of the battery system is evaluated, and a battery system health evaluation result is generated. The technical solution of this embodiment performs state of charge value detection, discharge, state of charge calibration, and charging during the actual operation of the vehicle, achieving the purpose of accurately evaluating the health state of the battery system under the actual operating conditions of the vehicle, realizing the technical effects of efficient and low-cost battery capacity detection and SOC calibration, and thus solving the technical problems of difficult battery state capacity testing and insufficient testing accuracy for long-term operating vehicles in the related art.

[0111] It should be noted that the above-mentioned various modules can be implemented by software or hardware. For the latter, it can be implemented in the following ways, but not limited to this: the above-mentioned modules are all located in the same processor; or, the above-mentioned various modules are separately located in different processors in any combination form.

[0112] An embodiment of the present invention also provides a computer program, which when executed by a processor implements the steps in any one of the above method embodiments of the present application.

[0113] Optionally, in this embodiment, the above computer program is executed by the processor to perform the following steps:

[0114] Step S1, when it is determined that the state of charge value of the battery system meets the preset discharge condition, the battery system is discharged until the single-cell voltage of the battery system meets the preset calibration condition;

[0115] Step S2, based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system, the state of charge value of the battery system is calibrated;

[0116] Step S3, the calibrated battery system is charged until the state of charge value of the battery system meets the preset full-charge condition;

[0117] Step S4, based on the original capacity and the actual charging capacity of the battery system, the health state of the battery system is evaluated, and a battery system health evaluation result is generated.

[0118] An embodiment of the present invention also provides a computer program product, including a computer program, which when executed by a processor implements the steps in any one of the above method embodiments of the present application.

[0119] Optionally, in this embodiment, when the computer program in the above computer program product is executed by a processor, the following steps are implemented:

[0120] Step S1, when it is determined that the state of charge value of the battery system meets the preset discharge condition, discharge the battery system until the single-cell voltage of the battery system meets the preset calibration condition;

[0121] Step S2, calibrate the state of charge value of the battery system based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system;

[0122] Step S3, charge the calibrated battery system until the state of charge value of the battery system meets the preset full charge condition;

[0123] Step S4, evaluate the health state of the battery system based on the original capacity and the actual charging capacity of the battery system, and generate a battery system health assessment result.

[0124] An embodiment of the present invention further provides a storage medium, in which a computer program is stored, and the computer program is configured to execute the steps in any one of the above method embodiments when running.

[0125] Optionally, in this embodiment, the above storage medium may be configured to store a computer program for executing the following steps:

[0126] Step S1, when it is determined that the state of charge value of the battery system meets the preset discharge condition, discharge the battery system until the single-cell voltage of the battery system meets the preset calibration condition;

[0127] Step S2, calibrate the state of charge value of the battery system based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system;

[0128] Step S3, charge the calibrated battery system until the state of charge value of the battery system meets the preset full charge condition;

[0129] Step S4, evaluate the health state of the battery system based on the original capacity and the actual charging capacity of the battery system, and generate a battery system health assessment result.

[0130] Optionally, in this embodiment, the above storage medium may include but is not limited to: various media that can store computer programs such as USB flash drives, read-only memories (ROM for short), random access memories (RAM for short), mobile hard disks, magnetic disks, or optical discs.

[0131] An embodiment of the present invention further provides a processor, which is configured to run a computer program to execute the steps in any one of the above method embodiments.

[0132] Optionally, in this embodiment, the above processor may be configured to execute the following steps through a computer program:

[0133] Step S1, when it is determined that the state of charge value of the battery system meets the preset discharge condition, discharge the battery system until the voltage of the single battery of the battery system meets the preset calibration condition;

[0134] Step S2, calibrate the state of charge value of the battery system based on the relationship curve between the state of charge value and the open-circuit voltage and the open-circuit voltage of the battery system;

[0135] Step S3, charge the calibrated battery system until the state of charge value of the battery system meets the preset full charge condition;

[0136] Step S4, evaluate the health state of the battery system based on the original capacity and the actual charge capacity of the battery system, and generate a health assessment result of the battery system.

[0137] An embodiment of the present invention further provides a vehicle, which has an on-vehicle battery system, and the on-vehicle battery system is health-assessed by using the above-mentioned health assessment method for the on-vehicle battery system.

[0138] By using the health assessment method for the on-vehicle battery system in the above embodiment to perform health assessment on the on-vehicle battery system, it is possible to effectively monitor and manage the health state of the on-vehicle battery system, improve the operation efficiency and safety of the vehicle, and is applicable to the maintenance and management of the battery systems of various electric vehicles.

[0139] In the above embodiments of the present invention, the descriptions of the various embodiments have their own focuses. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0140] In several embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the units or modules can be in an electrical or other form.

[0141] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or may be distributed over multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0142] In addition, each functional unit in various embodiments of the present invention may be integrated in a processing unit, may exist individually as a physical unit, or two or more units may be integrated in one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0143] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks or optical disks and other various media that can store program codes.

[0144] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A health assessment method for a vehicle-mounted battery system, characterized in that, Including: When it is determined that the state of charge value of the battery system meets the preset discharge condition, discharging the battery system until the cell voltage of the battery system meets the preset calibration condition; Calibrating the state of charge value of the battery system based on the relationship curve between the state of charge value and the open circuit voltage and the open circuit voltage of the battery system; Charging the calibrated battery system until the state of charge value of the battery system meets the preset full charge condition; Evaluating the health state of the battery system based on the original capacity and the actual charging capacity of the battery system, and generating a battery system health assessment result.

2. The health assessment method of the in-vehicle battery system according to claim 1, characterized in that Discharging the battery system until the cell voltage of the battery system meets the preset calibration condition includes: Discharging the battery system until at least one of the multiple cell voltages of the battery system is less than or equal to a preset cell voltage value, and the cell voltages are all greater than or equal to the cell protection voltage, where the preset cell voltage value is greater than the cell protection voltage; Obtaining the cell voltage difference of the battery system, where the cell voltage difference is the voltage difference between any two cells; When it is determined that the cell voltage difference meets the preset voltage difference condition, determining that the cell voltage of the battery system meets the preset calibration condition.

3. The health assessment method of the in-vehicle battery system according to claim 2, characterized in that, After obtaining the cell voltage difference of the battery system, the method further includes: When it is determined that the cell voltage difference does not meet the preset voltage difference condition, adjusting the cell voltage difference of the battery system by using an equalizing discharge strategy.

4. The health assessment method of the vehicle-mounted battery system according to claim 3, wherein After adjusting the cell voltage difference of the battery system by using an equalizing discharge strategy, the method further includes: When the equalizing discharge duration meets the preset duration condition and the cell voltage difference does not meet the preset voltage difference condition, stopping the discharge and generating a state abnormality prompt for the battery system, where the state abnormality prompt is at least used to prompt to replace the battery; Wherein, the equalizing discharge duration is used to represent the duration of adjusting the cell voltage difference of the battery system by using the equalizing discharge strategy.

5. The health assessment method of the in-vehicle battery system according to claim 1, characterized in that, When it is determined that the state of charge value of the battery system meets the preset discharge condition, discharging the battery system includes: When it is determined that the state of charge value of the battery system is less than or equal to a first preset value, discharging the battery system.

6. The health assessment method of the in-vehicle battery system according to claim 1, characterized in that, Charging the calibrated battery system until the state of charge value of the battery system meets the preset full charge condition includes: Charging the battery system until the state of charge value of the battery system is equal to the full charge state value.

7. The health assessment method of the vehicle-mounted battery system according to claim 1, wherein, Evaluating the health state of the battery system based on the original capacity and the actual charging capacity of the battery system, and generating a battery system health assessment result includes: Determining the remaining capacity ratio of the battery system based on the original capacity and the actual charging capacity of the battery system; Evaluating the health state of the battery system based on the remaining capacity ratio, and generating a battery system health assessment result.

8. The health assessment method of the vehicle-mounted battery system according to claim 7, characterized in that, The method further includes: Determining the remaining life of the battery system based on the battery system health assessment result and the battery life prediction model.

9. The health assessment method of the vehicle-mounted battery system according to claim 7, wherein The method further includes: Generate a battery maintenance strategy based on the remaining life of the battery system and the battery system health assessment result; Among them, the battery maintenance strategy includes at least one of the following: a battery replacement strategy and a battery usage pattern adjustment strategy.

10. A vehicle having an on-vehicle battery system, characterized in that, The on-vehicle battery system performs a health assessment by using the health assessment method of the on-vehicle battery system according to any one of claims 1-9.

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