Time compensation methods, battery management system, vehicle, server and service system

Abstract

This application relates to a time compensation method, a battery management system, a vehicle, a server, and a service system. It includes: obtaining a temperature difference threshold relationship, which includes the correspondence between temperature difference ranges and temperature thresholds; compensating for the battery's static dormancy time based on the temperature difference threshold relationship; where the temperature difference range characterizes the degree to which the battery's temperature deviated from a reference temperature during the previous power-off, and the temperature threshold characterizes the amount of temperature change corresponding to the duration of static dormancy during the power-off to power-on period within the corresponding temperature difference range. This method can compensate for the battery's static dormancy time in the event of an RTC failure, thereby enabling the BMS's functions such as SOC static correction, SOH online calculation, and static equalization calculation to operate normally.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a time compensation method, a battery management system, a vehicle, a server, and a service system. Background Technology

[0002] The Battery Management System (BMS) is a core component for ensuring the reliable operation and state management of batteries in new energy vehicles. The Real-Time Clock (RTC), as a key module in the BMS, records the static sleep time from when the vehicle is powered off to when it is powered on again. This static sleep time is the key basis for the BMS to realize static functions such as static correction of State of Charge (SOC), online calculation of State of Health (SOH), and static balancing.

[0003] Taking new energy commercial vehicles as an example, in related technologies, the main power supply for the RTC during operation relies on the vehicle's constant power supply (KL30), while the backup power supply is provided by the BMS button battery. However, in actual use, new energy commercial vehicles often experience scenarios where the KL30 is disconnected (such as long-term parking or maintenance), and the BMS button battery is prone to failure due to capacity decay. The dual power supply interruption will cause the RTC to stop timing and be unable to record static sleep time, leading to the failure of the BMS's static functions and thus significantly impacting the BMS's battery state management. Summary of the Invention

[0004] Therefore, it is necessary to provide a time compensation method, battery management system, vehicle, server and service system to address the above-mentioned technical problems. This method can compensate for the static dormancy time of the battery in the event of an RTC failure, thereby enabling the BMS's functions such as static SOC correction, online SOH calculation, and static equalization calculation to operate normally.

[0005] In a first aspect, this application provides a time compensation method for a BMS to compensate for the static sleep time of a battery in the event of an RTC failure, the method comprising:

[0006] The temperature difference threshold relationship is obtained, which includes the correspondence between the temperature difference range and the temperature threshold. The temperature difference range represents the degree to which the temperature of the battery deviates from the reference temperature during the last power-off. The temperature threshold represents the amount of temperature change of the battery during the resting time from power-off to power-on in the corresponding temperature difference range.

[0007] The static dormancy time of the battery is compensated based on the temperature difference threshold relationship.

[0008] In the technical solution of this application embodiment, the BMS can determine the battery's resting state from the last power-off to the current power-on based on the temperature difference range and temperature threshold in the temperature difference threshold relationship. Based on this resting state, the BMS compensates for the battery's resting dormancy time. This allows the BMS to determine a reasonable compensation dormancy time by using the battery's natural heat change characteristics from the last power-off to the current power-on, thereby compensating for the battery's static dormancy time and ensuring that the BMS's subsequent SOC static correction, SOH online calculation, and static equalization can be performed normally.

[0009] In one embodiment, the method further includes: determining the temperature difference between the battery's temperature during the vehicle's last power-off and a reference temperature; and determining the temperature change value of the battery from the vehicle's last power-off to the current power-on; accordingly, compensating for the battery's static dormancy time based on a temperature difference threshold relationship includes:

[0010] Based on the temperature difference range to which the temperature difference belongs, the corresponding temperature threshold is obtained from the temperature difference threshold relationship; based on the temperature threshold and the temperature change value, the static sleep time of the battery is determined; based on the static sleep time, the RTC is compensated.

[0011] In the technical solution of this application embodiment, the BMS combines the physical characteristics of the battery with the temperature change law of the battery under rest, and matches the temperature threshold in different grades to adapt to the temperature drop difference of different temperature environments, reduce the compensation error caused by environment or rest time, and through the correlation logic between temperature difference range and temperature threshold, converts the physical signal of battery temperature change into static sleep time, ensuring that functions such as SOC static correction, SOH calculation, and static equalization are executed normally.

[0012] In one embodiment, determining the static sleep time of the battery based on a temperature threshold and a temperature change value includes: determining the static sleep time as a first compensation value when the temperature change value is greater than or equal to the temperature threshold, the first compensation value representing the shortest duration required for the BMS to perform the battery static management function, the shortest duration being greater than 0; or determining the static sleep time as 0 when the temperature change value is less than the temperature threshold or when the temperature change value falls under other circumstances; other circumstances refer to any situation other than the temperature change value being greater than or equal to the temperature threshold and the temperature change value being less than the temperature threshold.

[0013] In the technical solution of this application embodiment, battery static sleep time compensation is performed through binary judgment logic, which eliminates the need for complex calculations and reduces the computing power consumption of the BMS to a certain extent. When RTC fails, the minimum static management duration compensation is provided when the temperature change value is greater than or equal to the temperature threshold, ensuring that functions such as SOC correction and static balancing have effective time support and avoiding functional paralysis. Moreover, the setting of the minimum duration is in line with the core requirements of battery static management, ensuring functionality while avoiding overcompensation, and balancing efficiency and accuracy. When the temperature change value is less than the temperature threshold or in other situations, the compensation value is set to 0, avoiding parameter calculation errors caused by invalid compensation and avoiding abnormal data interference, thereby improving system stability.

[0014] In one embodiment, the method further includes: if the static sleep time is determined to be a first compensation value, determining that the vehicle's stationary state is static, and notifying the cloud server so that the cloud server can verify the vehicle's stationary state.

[0015] In the technical solution of this application embodiment, when the vehicle is determined to be in a static state, the cloud server is notified so that the cloud server can verify the static state of the vehicle. This can avoid misjudgment caused by the failure of a single local sensor in the BMS or environmental interference, and improve the accuracy of the battery's static sleep time compensation function.

[0016] In one embodiment, determining the temperature difference between the battery temperature during the last power-off in the vehicle and a reference temperature includes: obtaining a first average temperature of multiple battery cells at the time of the last power-off; obtaining a reference temperature; the reference temperature being the lowest temperature during the most recent multiple complete charge-discharge cycles before the last power-off; and determining the temperature difference between the battery temperature during the last power-off in the vehicle and the reference temperature based on the temperature difference between the first average temperature and the reference temperature.

[0017] In the technical solution of this application embodiment, the reference temperature is the lowest temperature of the most recent multiple complete charge-discharge cycles before the last power-off. This is combined with the first average temperature of multiple cells at the time of power-off to calculate the temperature difference. This avoids extreme temperature interference from a single charge-discharge cycle and better reflects the long-term temperature change characteristics of the battery, making the temperature difference between the power-off temperature and the reference temperature more accurately reflect the true temperature difference of the battery. Calculating the temperature difference based on the average temperature of multiple cells reduces the impact of abnormal data from individual cells, improves the reliability of the temperature difference value, and provides a core basis for subsequent temperature threshold matching and static state determination, ensuring the normal operation of the BMS's static management function.

[0018] In one embodiment, determining the temperature change value of the battery from the last time the vehicle was powered off to the current time it was powered on includes: obtaining a first average temperature of a plurality of battery cells when the battery was last powered off, and obtaining a second average temperature of a plurality of battery cells when the battery is currently powered on; and determining the absolute value of the difference between the first average temperature and the second average temperature as the temperature change value.

[0019] In the technical solution of this application embodiment, calculating the average temperature of multiple cells can reduce the impact of abnormal data of a single cell and improve the reliability of temperature data calculation results. Moreover, the temperature change value is taken as the absolute value of the difference between the average temperature of multiple cells when powering on and off, which not only reduces the impact of abnormal data of a single cell, but also avoids interference from the direction of heating or cooling, focusing only on the magnitude of change, further improving the accuracy of data.

[0020] Secondly, embodiments of this application provide a time compensation method for compensating the static sleep time of the battery in the event of a failure of the real-time clock (RTC) of the BMS. This method, assisted by a cloud server, includes: generating a temperature difference threshold relationship for the vehicle; the temperature difference threshold relationship includes a correspondence between temperature difference intervals and temperature thresholds; the temperature difference interval represents the degree to which the temperature of the vehicle's battery deviates from a reference temperature during its last power-off, and the temperature threshold represents the amount of temperature change corresponding to the static sleep time of the battery during the period from power-off to power-on within the corresponding temperature difference interval; and sending the temperature difference threshold relationship to the vehicle's BMS so that the BMS compensates for the static sleep time of the battery based on the temperature difference threshold relationship.

[0021] In the technical solution of this application embodiment, the cloud server generates and sends the temperature difference threshold relationship to the vehicle's BMS, so that the BMS can determine the battery's resting state from the last power-off to the current power-on through the temperature difference range and temperature threshold in the temperature difference threshold relationship. Based on this resting state, the BMS compensates for the battery's resting dormancy time. In this way, the BMS can determine a reasonable compensation dormancy time by using the battery's natural heat change characteristics from the last power-off to the current power-on, and compensate for the battery's static dormancy time, ensuring that the BMS's subsequent SOC static correction, SOH online calculation, and static equalization can be performed normally.

[0022] In one embodiment, generating the vehicle's temperature difference threshold relationship includes: determining the vehicle's sleep time temperature difference relationship under the current power outage based on a sleep time temperature difference relationship table; the sleep time temperature difference relationship table includes the sleep time temperature difference relationships of batteries for multiple RTC fault vehicles under the current power outage; determining the vehicle's stationary state based on the sleep time temperature difference relationship; generating the vehicle's temperature difference threshold relationship if the stationary state determination result does not match the vehicle's static flag; the static flag indicates the vehicle's stationary state as determined by the vehicle's BMS.

[0023] In the technical solution of this application embodiment, the cloud server determines the stationary state based on the temperature difference relationship of the vehicle's hibernation time, making the determination of the vehicle's stationary state more reliable. Furthermore, the determination result is compared with the local static flag of the BMS to verify the local determination result, thus avoiding the limitations of local BMS determination. In addition, when the determination result does not match the stationary state determined locally by the BMS, a temperature difference threshold relationship for the vehicle is generated and sent to the BMS for temperature threshold correction, making subsequent stationary determinations by the BMS more accurate.

[0024] In one embodiment, the dormancy time temperature difference relationship includes the battery temperature change value and battery temperature difference corresponding to the current power outage of the vehicle; determining the vehicle's stationary state based on the dormancy time temperature difference relationship includes: determining the temperature difference range to which the vehicle's battery belongs under the current power outage based on the battery temperature difference; obtaining the current temperature threshold used by the BMS in the most recent determination of the vehicle's stationary state based on the temperature difference range; determining the vehicle's stationary state as static if the battery temperature change value is greater than or equal to the current temperature threshold; and determining the vehicle's stationary state as non-static if the battery temperature change value is less than the current temperature threshold.

[0025] In the technical solution of this application embodiment, the range is determined according to the battery temperature difference, so that the temperature threshold matches the current battery temperature change, avoiding the judgment deviation caused by the general threshold and improving the scenario adaptability of the static state judgment; and when the cloud server performs static state analysis and judgment of the vehicle, it reuses the current temperature threshold of the vehicle's BMS most recently judged, ensuring the consistency of the judgment standard and reducing the risk of misjudgment.

[0026] In one embodiment, the dormancy time temperature difference relationship also includes the vehicle's battery dormancy time and temperature change rate per unit time under the current power outage; generating the vehicle's temperature difference threshold relationship includes:

[0027] Based on the sleep time and temperature change rate per unit time, determine the BMS compensation error type; based on the compensation error type and the temperature change values ​​of multiple batteries under multiple power outages, determine the vehicle's correction temperature threshold; determine the temperature difference range and the correction temperature threshold as the temperature difference threshold relationship.

[0028] In the technical solution of this application embodiment, the cloud server combines the sleep time and the temperature change rate per unit time to determine the compensation error type, accurately locate the root cause of the error, provide a clear direction for threshold correction, and avoid blind adjustment; and determine the correction temperature threshold based on the error type and the battery temperature change value of the vehicle in multiple historical power outage cycles. Multiple sets of data support make the correction result fit the long-term temperature change characteristics of the vehicle, and improve the accuracy of temperature threshold correction.

[0029] Thirdly, embodiments of this application provide a battery management system, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods provided in the first aspect embodiment.

[0030] Fourthly, embodiments of this application provide a vehicle that includes the battery management system provided in the third aspect embodiments described above.

[0031] Fifthly, embodiments of this application provide a cloud server, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods provided in the second aspect embodiments.

[0032] Sixthly, embodiments of this application provide a vehicle service system, which includes the battery management system provided in the third aspect embodiment and the cloud server provided in the fifth aspect embodiment.

[0033] In a seventh aspect, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods provided in the first or second aspect embodiments.

[0034] Eighthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the methods provided in the first or second aspect embodiments. Attached Figure Description

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the alternative embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0036] Figure 1 This is a schematic diagram of the application environment of the time compensation method provided in an embodiment of this application;

[0037] Figure 2 This is a schematic flowchart of a time compensation method provided in an embodiment of this application;

[0038] Figure 3 This is a flowchart illustrating a time compensation method provided in another embodiment of this application;

[0039] Figure 4 This is a schematic diagram of the framework of a BMS-side execution time compensation method provided in an embodiment of this application;

[0040] Figure 5 This is a flowchart illustrating a time compensation method provided in another embodiment of this application;

[0041] Figure 6 This is a flowchart illustrating a time compensation method provided in another embodiment of this application;

[0042] Figure 7 This is a schematic diagram of the framework of a cloud execution time compensation method provided in an embodiment of this application. Detailed Implementation

[0043] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; in the description of embodiments of this application, technical terms such as "first," "second," etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0045] With the development of new energy technologies, batteries are being used in increasingly wider fields, such as in battery-powered new energy vehicles. Typically, the battery packs of new energy vehicles include a Real-Time Clock (RTC) to calculate sleep time. Functions such as State of Charge (SOC) static correction, State of Health (SOH) online calculation, and battery balancing all rely on the sleep time calculated by the RTC. When the vehicle is powered off, the coin cells in the battery management system supply power to the RTC. However, coin cells have a small capacity and are prone to depletion, failing to power the RTC and causing it to be unable to calculate sleep time. Alternatively, the RTC itself may malfunction. When these problems occur, functions such as SOC static correction, SOH online calculation, and battery balancing cannot obtain sleep time, affecting their operation.

[0046] To address the aforementioned issues, this application provides a time compensation method, a battery management system, a vehicle, a server, and a service system. The Battery Management System (BMS) can compensate for the battery's static sleep time when a real-time clock (RTC) fault is detected, thereby ensuring the normal operation of the BMS's SOC static correction, SOH online calculation, and static balancing functions. Furthermore, the cloud server can collaborate and verify with the local BMS, preventing errors in time compensation performed locally by the BMS when an RTC fault exists in the vehicle, further ensuring the normal operation of the BMS's SOC static correction, SOH calculation, and balancing functions.

[0047] The time compensation method provided in this application embodiment can be applied to, for example, Figure 1 The application environment shown includes vehicle 10 and cloud server 20; vehicle 10 communicates with cloud server 20 via a network. A data storage system can store data that cloud server 20 needs to process. The data storage system can be integrated into cloud server 20 or located in the cloud or on other network servers. Vehicle 10 includes a BMS (Battery Management System). Figure 1 (Not illustrated in the diagram) The BMS includes a Battery Management Unit (BMU), an RTC, etc. Temperature sensors are deployed in the battery of vehicle 10 to collect temperature data of the battery cells, allowing the BMU to read this temperature data and enable the BMS to execute the time compensation method provided in this embodiment. Vehicle 10 may also include a communication module through which the battery management unit interacts with the cloud server 20. The cloud server 20 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services; this embodiment does not limit its scope.

[0048] In this application's technical solution, the BMS compensates for the battery's static sleep time, requiring the cooperation and verification of a cloud server. The two work together to achieve accurate compensation for the battery's static sleep time and ensure the stability of the battery's core functions. It should be noted that in some practical applications, the BMS can also independently compensate for the battery's static sleep time. For example, when the BMS uses an initial default temperature difference threshold relationship for time compensation, the BMS performs the compensation independently. Based on this, this application provides embodiments of a time compensation method with the BMS as the execution entity and a time compensation method with a cloud server as the execution entity. The embodiment of the time compensation method executed locally by the BMS will be described first.

[0049] like Figure 2As shown in the embodiments of this application, a time compensation method is provided, which is applied to, for example... Figure 1 Taking a vehicle's BMS as an example, this time compensation method is specifically used by the BMS to compensate for the battery's static sleep time in the event of an RTC failure. This embodiment may include the following steps:

[0050] S101, obtain the temperature difference threshold relationship, which includes the correspondence between the temperature difference range and the temperature threshold; the temperature difference range represents the degree to which the temperature of the battery deviates from the reference temperature during the last power-off, and the temperature threshold represents the amount of temperature change of the battery during the resting time from power-off to power-on in the corresponding temperature difference range.

[0051] Normally, when a vehicle is powered off and then powered on again, the BMS will read the static sleep time of the vehicle's battery recorded by the RTC during this period. If the BMS cannot read the static sleep time recorded by the RTC or the static sleep time recorded by the RTC is invalid, the BMS will determine that the RTC is faulty.

[0052] For example, the static sleep time of the RTC record read by the BMS can be determined to be invalid when the time ScRTCR_SleepTimeLenSec is 0xFFFFFFFF. Of course, other values ​​can be defined to represent invalid values ​​in practical applications.

[0053] In addition, in this embodiment of the application, the BMS can notify the cloud server when it detects an RTC fault. For example, the BMS can upload the RTC fault flag of the vehicle to the cloud server through the BMU, or directly report that the static sleep time recorded by the RTC is an invalid value to the remote server, so that the cloud server can verify the static state of the vehicle based on this information.

[0054] When the BMS determines an RTC fault, it obtains a temperature difference threshold relationship, which refers to the correspondence between temperature difference ranges and temperature thresholds. The temperature difference range characterizes the degree to which the battery temperature deviated from the reference temperature during the last power-off. The reference temperature refers to the baseline temperature of the operating environment when the vehicle was last powered off. For example, the average temperature of the battery cell system collected and stored by the BMS at the moment of power-off can be used to represent the normal baseline temperature of the operating environment at the time of power-off. In this embodiment, the temperature difference range includes multiple ranges, each representing a different degree of deviation of the battery temperature from the reference temperature when the vehicle is powered off. For example, the temperature difference ranges include T≤20℃, 20℃<T≤40℃, and T>40℃. T≤20℃ means the battery temperature deviated from the reference temperature by less than 20℃ when the vehicle was powered off; 20℃<T≤40℃ means the battery temperature deviated from the reference temperature by less than 20℃; T>40℃ means the battery temperature deviated from the reference temperature by more than 40℃ when the vehicle was powered off.

[0055] Each temperature range corresponds to a temperature threshold, which represents the amount of temperature change required for the battery to reach a resting state during the period from power-off to power-on within that temperature range. In other words, it can be understood as the amount of temperature change required for the battery to reach a resting state within a given temperature range during the period from power-off to power-on. For example, the temperature threshold for a temperature range T≤20℃ is 5℃, meaning that for a battery in the T≤20℃ range, the temperature change during power-off to power-on must be at least 5℃ to indicate that the battery has reached a resting state. The temperature threshold for a temperature range 20℃<T≤40℃ is 8℃, meaning that for a battery in the 20℃<T≤40℃ range, the temperature change during power-off to power-on must be at least 8℃ to indicate that the battery has reached a resting state. The temperature threshold for a temperature range T>40℃ is 10℃, meaning that for a temperature range T>40℃, the temperature change during power-off to power-on must be at least 10℃ to indicate that the battery has reached a resting state.

[0056] In practical applications, temperature difference ranges can be divided based on the degree of deviation between the battery temperature and the reference temperature when different vehicles are powered off, based on a large amount of experimental data, and the temperature threshold of each temperature difference range can be calibrated based on statistical data.

[0057] In this embodiment of the application, the BMS can obtain the temperature difference threshold relationship in real time by receiving the temperature difference threshold relationship sent by the cloud server. For example, when the BMS determines that the RTC is faulty, it requests the temperature threshold of the temperature difference range to which the battery belongs when the vehicle was last powered off, and receives the temperature difference threshold relationship between the temperature difference range and the temperature threshold sent by the cloud server.

[0058] The BMS can also obtain temperature difference threshold relationships from a pre-stored temperature difference threshold relationship table. For example, in the initial stage, the BMS can configure multiple temperature difference ranges and their corresponding initial default temperature thresholds locally based on user configuration commands, and store these in a temperature difference threshold relationship table. The temperature thresholds corresponding to each temperature difference range in this table are collaboratively verified by the cloud server. If the cloud server finds that the temperature threshold corresponding to a certain temperature difference range is inaccurate, it can send the corrected temperature threshold for that range to the BMS. The BMS then updates its locally stored temperature difference threshold relationship table based on the relationship between the temperature difference ranges and temperature thresholds sent by the cloud server. In this way, the BMS can obtain the required temperature difference threshold relationships from this table when retrieving them.

[0059] S102, compensates for the static dormancy time of the battery based on the temperature difference threshold relationship.

[0060] Based on the obtained temperature difference threshold relationship, the BMS can compensate for the static sleep time of the battery. That is, the BMS re-determines a reasonable sleep time based on the obtained temperature difference threshold relationship to replace the static sleep time of the battery during the period from when the vehicle is powered off to when it is powered on again, so as to make up for the sleep time of the battery that was not recorded by the RTC fault.

[0061] The temperature threshold in the temperature difference threshold relationship represents the amount of temperature change of the battery during the period from power-off to power-on within the corresponding temperature difference range. Based on this, the BMS compensates for the static sleep time of the battery according to the temperature difference threshold relationship. It can first determine the battery temperature data from the last power-off to the current power-on and obtain the temperature difference threshold relationship to determine whether the battery has reached a static state during the period from the last power-off to the current power-on. Based on the determined static state of the battery, a reasonable sleep time is determined as the compensated static sleep time in combination with preset rules.

[0062] Here, the preset rule refers to the rule used by the BMS to determine the battery's static sleep time. This rule is pre-configured in the BMS. For example, the preset rule could be set based on the temperature change value between the battery's temperature at the last power-off and the temperature at the current power-on, and the actual rate of temperature change (e.g., temperature change value / actual rate of temperature change). Alternatively, the preset rule could be based on historical real data to establish a mapping relationship between temperature change values ​​and sleep time, directly determining the successfully matched sleep time as the compensated static sleep time for the battery. It could also be a fixed value set based on historical real data as the compensated static sleep time for the battery, etc. This application embodiment does not specifically limit the setting of the preset rule, as long as a reasonable sleep duration can be determined.

[0063] In this embodiment, the essence of BMS compensating for the static dormancy time of the battery based on the temperature difference threshold relationship is to reasonably restore the actual dormancy time of the battery based on the physical characteristics of the temperature change of the battery during the vehicle power-off period, thereby avoiding the failure of functions such as SOC static correction and SOH calculation caused by RTC fault.

[0064] In this embodiment, the BMS compensates for the battery's static dormancy time by acquiring a temperature difference threshold relationship in the event of an RTC failure. This temperature difference threshold relationship includes a correspondence between temperature difference ranges and temperature thresholds. The temperature difference range represents the degree to which the battery's temperature deviated from the reference temperature during the previous power-off, and the temperature threshold represents the amount of temperature change corresponding to the duration of rest during the power-off to power-on period within the corresponding temperature difference range. In this method, the BMS can determine the battery's resting status from the vehicle's last power-off to the current power-on based on the temperature difference range and temperature threshold in the temperature difference threshold relationship. Based on this resting status, the BMS compensates for the battery's resting dormancy time. This allows the BMS to determine a reasonable compensation dormancy time by using the battery's natural thermal changes during the period from the vehicle's last power-off to the current power-on, thus compensating for the battery's static dormancy time and ensuring that subsequent SOC static correction, SOH online calculation, and static equalization by the BMS can be performed normally.

[0065] Based on the above embodiments, the following several embodiments provide an implementation method for BMS to compensate for the static sleep time of the battery based on the temperature difference threshold relationship.

[0066] like Figure 3 As shown, in one embodiment, the above S102 includes the following steps:

[0067] S201, based on the temperature difference range to which the temperature difference belongs, obtain the corresponding temperature threshold in the temperature difference threshold relationship.

[0068] Here, temperature difference refers to the temperature difference between the battery temperature at the time of the vehicle's last power-off, as determined by the BMS, and a reference temperature. Based on this temperature difference, the BMS can determine the temperature range to which the battery belonged during the vehicle's last power-off. Thus, the BMS can determine the temperature threshold corresponding to this temperature range in the temperature difference threshold relationship as the temperature threshold required to determine the battery's resting condition from the last power-off to the current power-on.

[0069] For example, if the temperature difference falls within the range T ≤ 20℃, and assuming the temperature threshold corresponding to the T ≤ 20℃ range is 5℃, then the required temperature threshold for the battery's static state during the period from the last power-off to the current power-on is 5℃. The logic is the same for other temperature ranges, and will not be elaborated further here. This tiered design of temperature ranges allows the BMS to adapt to changes in battery temperature characteristics under different scenarios, regardless of climate, environment, or vehicle power-off duration, improving scenario versatility. Furthermore, the established correspondence between temperature ranges and temperature thresholds provides clear judgment criteria, and the judgment logic is reproducible, enabling the BMS to easily trace faults when compensating for battery static sleep time.

[0070] S202, determine the static dormancy time of the battery based on the temperature threshold and temperature change value.

[0071] The temperature change value refers to the amount of temperature change in the battery determined by the BMS from the last time the vehicle was powered off to the current time it was powered on. It reflects the heat change of the battery during the period from the last time the vehicle was powered off to the current time it was powered on. The temperature threshold is a threshold that can be used to determine the resting state of the battery during the period from the last time the vehicle was powered off to the current time it was powered on. Therefore, based on the temperature threshold and the temperature change value, the resting state of the battery during the period from the last time the vehicle was powered off to the current time it was powered on can be determined. Then, based on the resting state of the battery, the BMS can further determine the static dormancy time of the battery in conjunction with the preset rules mentioned in the aforementioned embodiments.

[0072] In this embodiment, the BMS determines the battery's static dormancy time based on a temperature threshold and a temperature change value by comparing the two. The determination logic follows that the temperature threshold is used as the basis for determining whether the battery has reached a static state. For example, if the temperature change value exceeds the temperature threshold, the battery is considered to have reached a static state. In another implementation, the BMS can also use the temperature threshold and temperature change value as input to an algorithm model, which analyzes and determines the battery's static state. This algorithm model can be deployed locally on the BMS, on a cloud server, or on other third-party devices.

[0073] S203 compensates for RTC based on static sleep time.

[0074] Based on the determined static sleep time, the BMS compensates the RTC by directly assigning the determined static sleep time to the sleep time of the battery recorded by the RTC. For example, if the determined sleep time is 61min / 3660s, then ScRTCR_SleepTimeLen=61min / 3660s.

[0075] In this embodiment, the BMS combines the physical characteristics of the battery with the temperature change pattern of the battery during rest, and matches the temperature threshold in different grades to adapt to the temperature drop differences in different temperature environments, reducing the compensation error caused by the environment or resting time. Furthermore, through the correlation logic between the temperature difference range and the temperature threshold, the physical signal of battery temperature change is converted into static sleep time, avoiding the failure of functions such as SOC static correction, SOH calculation, and static equalization.

[0076] In one embodiment, an implementation of determining the static sleep time of the battery based on a temperature threshold and a temperature change value may include the following steps: when the temperature change value is greater than or equal to the temperature threshold, determining the static sleep time as a first compensation value, the first compensation value representing the shortest duration required for the BMS to perform the battery static management function, the shortest duration being greater than 0; or, when the temperature change value is less than the temperature threshold or the temperature change value falls under other circumstances, determining the static sleep time as 0; other circumstances refer to any situation other than the temperature change value being greater than or equal to the temperature threshold and the temperature change value being less than the temperature threshold.

[0077] The BMS determines the battery's resting status based on the relationship between the temperature change value and the temperature threshold.

[0078] In this context, a temperature change value greater than or equal to a temperature threshold indicates that the battery's temperature change during the period from the vehicle's last power-off to the current power-on meets the temperature change threshold corresponding to the required resting time, thus determining the battery to be in a resting state. In this case, the battery's static sleep time can be set to a preset first compensation value. This preset first compensation value is a minimum duration required for the BMS to perform battery static management functions, which can be set based on empirical data and is greater than 0. For example, assuming in practical applications, the BMS compares the static sleep time recorded by the RTC with 60 minutes, and determines the resting state as "yes" when it exceeds 60 minutes, considering the requirement of exceeding 60 minutes, the first compensation value can be set to 61 minutes. This 61 minutes is the minimum duration required for the BMS to perform battery static management functions; that is, when the change in battery temperature between the last power-off and the current power-on is greater than or equal to the temperature threshold, the battery's static sleep time ScRTCR_SleepTimeLen is set to 61 minutes, or ScRTCR_SleepTimeLenSec = 3660 seconds.

[0079] In this case, a temperature change value less than the temperature threshold indicates that the battery temperature change was very small between the last power-off and the current power-on. This means the battery had a very short resting time during the power-off period, such as when the vehicle was powered on immediately after being powered off, or when the vehicle was only parked for a few minutes. Therefore, the battery is considered not to have reached a resting state. In these situations, the battery has almost no need for self-discharge, static aging, SOC, and SOH calculations, and the BMS's requirement for the battery's static sleep time is also very low. Therefore, the sleep time can be directly determined to be 0. For example, if the change value between the battery temperature at the last power-off and the current power-on temperature is less than the temperature threshold, the battery's static sleep time ScRTCR_SleepTimeLen is set to 0. In this way, setting it to 0 seconds will not affect the calculation accuracy of the BMS's static management function, and will also avoid misjudgment by the BMS due to setting a false static sleep time.

[0080] Additionally, if the battery temperature change value between the vehicle's last power-off and current power-on falls under the "other circumstances" category (meaning any situation other than a temperature change value greater than or equal to a temperature threshold or a temperature change value less than a temperature threshold, such as an invalid temperature change value, invalid temperature data itself, or other special cases), the battery's static sleep time can be set to 0. This allows the BMS to perform static management functions based on the battery being in a non-static state. Of course, if it's necessary to remind the BMS that subsequent functions do not rely on the static sleep time when the temperature change value falls under "other circumstances," the battery's static sleep time can be directly set to an invalid value. This allows the BMS to more accurately and flexibly respond to subsequent battery management in different situations.

[0081] In this embodiment, battery static sleep time compensation is performed using binary decision logic, eliminating the need for complex calculations and reducing the computational burden on the BMS to some extent. When the RTC fails, a minimum static management duration compensation is provided when the temperature change value is greater than or equal to the temperature threshold, ensuring that functions such as SOC correction and static balancing have effective time support and preventing functional paralysis. Furthermore, the setting of the minimum duration aligns with the core requirements of battery static management, ensuring functionality while avoiding overcompensation, thus balancing efficiency and accuracy. When the temperature change value is less than the temperature threshold or in other situations, the compensation value is set to 0, avoiding parameter calculation errors caused by invalid compensation while mitigating abnormal data interference and improving system stability.

[0082] When the BMS determines that the vehicle is in a static state, it will synchronize this determination result with the cloud server so that the cloud server can collaboratively verify whether the BMS's determination result is correct. In one embodiment, if the static sleep time is determined to be the first compensation value, the vehicle's static state is determined to be static, and the cloud server is notified so that the cloud server can verify the vehicle's static state.

[0083] Static flags can be pre-set; for example, 1 indicates the battery is in a static state, and 0 indicates the battery is not in a static state. The BMS can then upload these static flags to the cloud server via the BMU to notify the cloud server that the BMS determined the battery was in a static state during the vehicle's most recent power outage. This method of having the cloud server verify the vehicle's static state avoids misjudgments caused by single local sensor failures or environmental interference, improving the accuracy of the battery's static sleep time compensation function.

[0084] The following two embodiments illustrate an achievable method for a BMS to determine the temperature difference between the battery temperature at the last power-off point in the vehicle and a reference temperature, as well as to determine the temperature change of the battery from the last power-off point to the current power-on point.

[0085] In one embodiment, determining the temperature difference between the battery temperature during the last power-off of the vehicle and a reference temperature includes obtaining a first average temperature and a reference temperature of multiple battery cells at the time of the last power-off, and determining the temperature difference between the battery temperature during the last power-off of the vehicle and the reference temperature based on the temperature difference between the first average temperature and the reference temperature; the reference temperature is the lowest temperature under the most recent multiple complete charge-discharge cycles before the last power-off.

[0086] In this embodiment of the application, when acquiring temperature data, it is necessary to determine that the cell temperature data collected by the temperature sensor is valid. For example, after the power-on reaches 1 second, it is determined that the cell temperature data has been effectively uploaded, and then the temperature data calculation is started.

[0087] Specifically, the first average temperature of the battery cells at the time of the last power-off can be determined based on the temperature data of each cell pre-stored in the non-volatile memory (NVM) immediately before the vehicle's last power-off. The reference temperature can be determined based on the temperature data of the battery during the most recent multiple complete charge-discharge cycles pre-stored in the NVM, using this data to determine the lowest temperature representing the battery's reference temperature during those most recent multiple complete charge-discharge cycles. For example, the reference temperature can be determined based on the lowest temperature during the 10 most recent complete charge-discharge cycles before the vehicle's last power-off.

[0088] The temperature difference between the first average temperature and the reference temperature is defined as the temperature difference between the battery's temperature during the last power-off in the vehicle and the reference temperature. This temperature difference is used to determine the temperature range to which the battery belonged during the last power-off in the vehicle. In this embodiment, the temperature difference can also be an absolute value. For example, if the calculated temperature difference between the first average temperature and the reference temperature is 15°C, then the temperature range to which the battery belonged during the last power-off in the vehicle is determined to be T≤20°C. Then, based on the correspondence between the temperature range and the temperature threshold, the temperature threshold is determined to be 5°C. Similarly, the logic for the temperature ranges of 20°C<T≤40°C and T>40°C is the same, and will not be elaborated here.

[0089] In this embodiment, the reference temperature is the lowest temperature from the most recent multiple complete charge-discharge cycles before the last power-off. This temperature difference is calculated by combining the first average temperature of multiple cells at the time of power-off, avoiding extreme temperature interference from a single charge-discharge cycle and better reflecting the long-term temperature variation characteristics of the battery. This makes the temperature difference between the power-off temperature and the reference temperature more accurately reflect the true temperature difference of the battery. Calculating the temperature difference based on the average temperature of multiple cells reduces the impact of abnormal data from individual cells, improves the reliability of the temperature difference value, and provides a core basis for subsequent temperature threshold matching and static state determination, ensuring the normal operation of the BMS's static management functions.

[0090] In one embodiment, determining the temperature change value of the battery from the last time the vehicle was powered off to the current time it was powered on includes: obtaining a first average temperature of a plurality of battery cells at the time of the last power-off, and obtaining a second average temperature of the plurality of battery cells at the time of the current power-on; and determining the absolute value of the difference between the first average temperature and the second average temperature as the temperature change value.

[0091] The second average temperature is the average temperature of each cell in the battery at the moment the vehicle is currently powered on. This average temperature can be determined based on the temperature data of each cell uploaded by the temperature sensor when the vehicle is powered on.

[0092] Based on the first average temperature obtained earlier, the absolute value of the difference between the first average temperature and the second average temperature is determined as the temperature change value. Here, considering that the battery temperature may decrease or increase during the period from the last power-off to the current power-on, the absolute value of the difference between the first average temperature and the second average temperature is used when calculating the temperature change value.

[0093] In this embodiment, calculating the average temperature of multiple cells can reduce the impact of abnormal data from a single cell and improve the reliability of the temperature data calculation results. Furthermore, the temperature change value is taken as the absolute value of the difference between the average temperatures of multiple cells when powering on and off, which not only reduces the impact of abnormal data from a single cell but also avoids interference from the direction of heating or cooling, focusing only on the magnitude of the change and further improving the accuracy of the data.

[0094] Please see Figure 4 A flowchart illustrating the BMS execution time compensation method in an embodiment of this application. From Figure 4 It can be seen that after the BMS starts up at the current power-on moment of the vehicle, it reads the battery's sleep time recorded by the RTC during the power-off period. When it detects that ScRTCR_SleepTimeLen=0xFFFFFFFF or ScRTCR_SleepTimeLenSec=0xFFFFFFFF, it determines that the RTC is faulty. Then, it waits for 1 second after the vehicle is powered on (1 second is the average cell temperature upload time, indicating that the temperature data is valid) before starting to execute the locally preset time compensation strategy to compensate for the battery's static sleep time.

[0095] Specifically, the BMS executes the following steps: First, it reads the lowest battery temperature from the NVM over the last 10 cycles as the reference temperature of the battery at the time of the vehicle's last power-off. Next, it reads the average cell temperature from the NVM at the time of the vehicle's last power-off as the first average cell temperature. Then, it obtains the average cell temperature collected at the time of the vehicle's current power-on as the second average cell temperature. Assuming these temperature data are valid, it calculates the temperature difference |ΔT1| between the first average cell temperature and the reference temperature, and the absolute value |ΔT| between the first and second average cell temperatures. Based on |ΔT1|, it determines the temperature range to which the battery belonged at the time of the vehicle's last power-off from a pre-stored temperature difference threshold relationship (T≤20℃, corresponding to Thre=5℃; 20℃<T≤40℃, corresponding to Thre=8℃; T>40℃, corresponding to Thre=10℃). The temperature threshold of this temperature range is then determined as the Thre temperature threshold to be used for battery time compensation. The temperature difference threshold relationship can be the initial default value configured by the user for the BMS in the initial state, or it can be the temperature difference threshold relationship updated by the cloud server at a certain stage of vehicle operation.

[0096] Among them, with Figure 4Taking the temperature difference threshold relationship as an example, if |△T1| is determined to be within T≤20℃, then the temperature threshold Thre is determined to be 5℃; if |△T1| is determined to be within 20℃<T≤40℃, then the temperature threshold Thre is determined to be 8℃; if |△T1| is determined to be within T>40℃, then the temperature threshold Thre is determined to be 10℃. Based on the determined temperature threshold Thre, the BMS compares the magnitude of |△T| with the temperature threshold Thre. If |△T| is greater than Thre, the static sleep time compensated for by the battery is determined to be 61 minutes; if |△T| is less than Thre, the static sleep time compensated for by the battery is determined to be 0; if |△T| is fault data or other situations, the static sleep time of the battery is determined to be an invalid value. Depending on actual needs, in this case, the static sleep time of the battery can also be directly set to 0.

[0097] In this embodiment, a time compensation strategy is configured locally in the BMS. When the BMS detects an RTC fault, this strategy is activated to compensate for the battery's static sleep time, forming an alternative solution for the battery's static sleep time when the RTC fails, based on the battery's physical temperature change characteristics. Furthermore, by using the lowest temperature of 10 cycles as the baseline temperature and combining it with the average temperature of the cells when the vehicle was last powered off, the temperature difference is calculated, effectively avoiding interference from extreme temperatures, making the temperature difference range matching more accurate, and ensuring reliable temperature threshold selection. Temperature thresholds are set in tiers for the temperature difference range and support cloud updates, allowing for flexible adaptation to different climate scenarios and battery aging characteristics, making it highly versatile. The compensation time is determined by comparing the temperature change value with the temperature threshold, resulting in simple logic, reduced BMS computing power consumption, and compatibility with existing hardware without additional hardware. Simultaneously, using the average temperature of multiple cells when calculating temperature data can reduce single-point data errors, and abnormal data adaptation processing can avoid interference, ensuring continuous operation of core functions such as SOC correction and SOH calculation when the RTC fails, reducing compensation errors, and improving the reliability of the BMS's time compensation function.

[0098] The following describes an embodiment of a time compensation method executed by a cloud server. This time compensation method, executed by the cloud server, assists the BMS in compensating for battery static sleep time in the event of a BMS RTC failure. Figure 5 As shown, in one embodiment, this application provides a time compensation method, the method comprising:

[0099] S301, Generate the temperature difference threshold relationship of the vehicle; the temperature difference threshold relationship includes the correspondence between the temperature difference range and the temperature threshold; the temperature difference range represents the degree to which the temperature of the vehicle's battery deviates from the reference temperature during the last power-off, and the temperature threshold represents the amount of temperature change of the battery during the period from power-off to power-on in the corresponding temperature difference range, corresponding to the resting time.

[0100] The cloud server can proactively generate temperature difference threshold relationships for vehicles. Here, "vehicle" refers to any vehicle among all vehicles managed by the cloud server that has an RTC (Real-Time Control) fault. The cloud server can manage multiple vehicles simultaneously. Each vehicle's BMS (Battery Management System) uploads an RTC fault flag to the cloud server via its BMU (Battery Management Unit) when it detects its own RTC fault. The cloud server checks the RTC fault flags of all vehicles it manages at a certain frequency, filtering out all vehicles with RTC faults. It then verifies the static state of each vehicle with an RTC fault. If the BMS's determination of a vehicle's static state is incorrect, it generates a temperature difference threshold relationship for that vehicle. This temperature difference threshold relationship includes a temperature difference range and a temperature threshold. For a description of the temperature difference range and temperature threshold, please refer to the BMS-side implementation example; it will not be repeated here.

[0101] The temperature difference threshold relationship generated by the cloud server for the vehicle is not a relationship between all temperature difference ranges and their corresponding temperature thresholds, but rather a relationship between the temperature difference range to which the battery belonged when the vehicle was last powered off, determined during the verification process. For example, if the cloud server determines that the battery's temperature difference range is T≤20℃ during the verification of the vehicle's stationary state, then it establishes a temperature difference threshold relationship between T≤20℃ and the calculated correct temperature threshold for that temperature difference range.

[0102] In some cases, the cloud server can also passively generate temperature difference threshold relationships, i.e., upon receiving a request signal from the BMS of a vehicle it manages. This could occur if the temperature difference threshold relationship stored locally in the BMS is lost, the BMS lacks the function to store it locally, a malfunction occurs when the BMS calls the temperature difference threshold relationship, or the BMS has not received an update command from the cloud server for a certain period. In these situations, the BMS will send a request signal for the temperature difference threshold relationship to the cloud server in real time when it detects an RTC fault. This request signal can further specify the required temperature difference range, so the cloud server only needs to generate the temperature difference threshold relationship from the temperature difference range requested by the BMS and its corresponding temperature thresholds.

[0103] S302, send the temperature difference threshold relationship to the vehicle's BMS so that the BMS can compensate for the battery's static dormancy time according to the temperature difference threshold relationship.

[0104] The cloud server sends the generated temperature difference threshold relationship to the vehicle's BMS, so that the BMS can use the temperature difference threshold relationship to compensate for the battery's static sleep time, or the BMS can update the locally stored temperature difference threshold relationship table based on the received temperature difference threshold relationship.

[0105] In this embodiment, the cloud server generates and distributes a temperature difference threshold relationship to the vehicle's BMS. This relationship includes a correspondence between temperature difference ranges and temperature thresholds. The temperature difference range represents the degree to which the battery's temperature deviated from the reference temperature during the previous power-off, and the temperature threshold represents the amount of temperature change corresponding to the battery's resting time during the corresponding temperature difference range from power-off to power-on. Thus, the BMS can determine the battery's resting status from the previous power-off to the current power-on using the temperature difference range and temperature threshold in the relationship. Based on this resting status, it compensates for the battery's resting dormancy time. This allows the BMS to determine a reasonable compensation dormancy time by using the battery's natural thermal changes during the period from the previous power-off to the current power-on, compensating for the battery's static dormancy time and ensuring that subsequent SOC static correction, SOH online calculation, and static equalization by the BMS can be performed normally.

[0106] The following example illustrates the process of the cloud server generating the temperature difference threshold relationship of vehicles by taking the scenario where the cloud server actively manages all RTC vehicles.

[0107] In one embodiment, such as Figure 6 As shown, the process of generating the temperature difference threshold relationship for vehicles includes:

[0108] S401, determine the sleep time temperature difference relationship of the vehicle under the current power failure according to the sleep time temperature difference relationship table; the sleep time temperature difference relationship table includes the sleep time temperature difference relationship of the battery of multiple RTC fault vehicles under the current power failure.

[0109] The sleep time temperature difference relationship table is established by the cloud server based on the vehicle data of all vehicles with RTC faults selected by the managed vehicles. The sleep time temperature difference relationship table is shown in Table 1 below, which includes the relationship between the battery sleep time and temperature difference of each vehicle with RTC fault during the most recent power outage.

[0110] Table 1

[0111]

[0112] The data in Table 1 above is only one example. For ease of illustration, typical data is sampled. A total of 18 sets of data represent the temperature difference relationship of the sleep time of 18 vehicles with RTC faults.

[0113] Specifically, the cloud server traverses the vehicle data of all managed vehicles. This vehicle data is uploaded by the BMU in each vehicle's BMS. This vehicle data includes at least the temperature data of each cell in each vehicle's battery at various times, the displayed SOC, the battery cycle data under each charge-discharge cycle, as well as the battery's static flags and the vehicle's RTC fault flags. Based on the vehicle's RTC fault flags, the cloud server filters out vehicles with RTC faults and then begins to calculate for each vehicle with an RTC fault: the battery temperature change value and battery temperature difference under the current power outage, the vehicle's battery dormancy time and temperature change rate per unit time under the current power outage, etc., to establish the aforementioned dormancy time-temperature difference relationship table.

[0114] The cloud server first performs a validity screening of vehicle data for each RTC-faulted vehicle. Based on the displayed State of Charge (SOC) at the most recent power-down and power-up timestamps for each RTC-faulted vehicle, vehicle data with consistent SOC and timestamp intervals exceeding 30 minutes are filtered out. Data with intervals less than 30 minutes is considered temporary power-downs and is defined as invalid data. A baseline temperature T0 is determined based on the lowest temperature of the last 10 charge-discharge cycles for each of the filtered RTC-faulted vehicles at the most recent power-down timestamp. The average cell temperature Tlast is calculated based on the temperature data of each cell at the most recent power-down timestamp, and the average cell temperature Tagv is calculated based on the temperature data of each cell at the most recent power-up timestamp. Then, for a single vehicle, the time difference between the vehicle's most recent power-on time and most recent power-off time is determined as the battery's dormancy time. The absolute value of the difference between Tlast and T0 is taken as the vehicle's battery temperature difference. The absolute value of the difference between Tagv and Tlast is taken as the vehicle's battery temperature change value. The ratio of the battery temperature change value to the dormancy time is determined as the vehicle's battery temperature change rate per unit time.

[0115] Therefore, the battery temperature change values, battery temperature difference, sleep time, and temperature change rate per unit time of multiple RTC-faulted vehicles were calculated. Based on this data, a sleep time-temperature difference relationship table was established for these multiple RTC-faulted vehicles. Based on this sleep time-temperature difference relationship table, the cloud server can obtain the sleep time-temperature difference relationship of any vehicle to be verified.

[0116] S402 determines the stationary state of the vehicle based on the temperature difference relationship during dormancy.

[0117] After the cloud server obtains the sleep time temperature difference relationship of the vehicle to be verified, it means that it has obtained parameters such as the battery temperature change value, battery temperature difference, sleep time and temperature change rate per unit time under the current power outage cycle. Then, it analyzes the static state of the vehicle based on these parameters.

[0118] In one embodiment, a state analysis model can be constructed based on parameters such as battery temperature change, battery temperature difference, dormancy time, and temperature change rate per unit time, according to the relationship between the dormancy time and temperature difference of multiple vehicles statistically analyzed under historical power outages. The relevant parameters of the vehicle are input into the state analysis model, and the static state of the vehicle is analyzed through the state analysis model.

[0119] In another embodiment, the process of determining the vehicle's stationary state based on the temperature difference relationship during sleep time includes: determining the temperature difference range to which the vehicle's battery belongs under the current power outage based on the battery temperature difference; obtaining the current temperature threshold used by the BMS in the most recent determination of the vehicle's stationary state based on the temperature difference range; determining the vehicle's stationary state as static if the battery temperature change value is greater than or equal to the current temperature threshold; and determining the vehicle's stationary state as non-static if the battery temperature change value is less than the current temperature threshold.

[0120] The cloud server determines the temperature range to which the vehicle belongs based on its battery temperature difference, and obtains the current temperature threshold used by the vehicle's BMS within that temperature range. The vehicle's static state is determined by comparing the battery temperature change with the current temperature threshold. Specifically, a battery temperature change greater than or equal to the current temperature threshold indicates a static state, while a battery temperature change less than the current temperature threshold indicates a non-static state. The principles and logic behind this static state determination based on the magnitude relationship are the same as those on the BMS side; please refer to the BMS-side documentation.

[0121] For example, please refer to the first row of Table 2 below. If the battery temperature difference of the vehicle is 15℃, the temperature difference range is determined to be T≤20℃. Assuming the current temperature threshold used by the vehicle's BMS in the T≤20℃ temperature difference range is 5℃, then the battery temperature change value of 4℃ is compared with this 5℃ to determine that the vehicle's stationary state is non-static. Similarly, the stationary states determined by this logic in the second row to the last row of Table 2 are shown in Table 2. The current temperature thresholds in Table 2 are illustrated using the following example: a temperature threshold of 5 for the T≤20℃ temperature difference range, a temperature threshold of 8 for the 20<T≤40℃ temperature difference range, and a temperature threshold of 10 for the T>40℃ temperature difference range.

[0122] Table 2

[0123]

[0124] In this embodiment, the range is determined by the battery temperature difference, so that the temperature threshold matches the current battery temperature change, avoiding the judgment deviation caused by the general threshold and improving the scenario adaptability of the static state judgment; and when the cloud server performs static state analysis and judgment of the vehicle, it reuses the current temperature threshold of the vehicle's BMS most recently judged, ensuring the consistency of the judgment standard and reducing the risk of misjudgment.

[0125] S403, if the result of determining the stationary state does not match the vehicle's static flag, generate the temperature difference threshold relationship of the vehicle; the static flag indicates the stationary state of the vehicle as determined by the vehicle's BMS.

[0126] If the static state determination result matches the vehicle's static flag, it means that the static state determined by the cloud server is the same as the static state determined by the vehicle's BMS, indicating that the static state determined by the vehicle's BMS is correct and no intervention is needed. However, if the static state determination result does not match the vehicle's static flag, it means that the static state determined by the cloud server is different from the static state determined by the vehicle's BMS. Therefore, the temperature threshold used by the BMS needs to be corrected. In this case, the cloud server needs to generate the vehicle's temperature difference threshold relationship and send it to the vehicle's BMS.

[0127] For example, a cloud server can determine the corrected temperature threshold for a vehicle within its temperature range based on a preset mapping relationship between the temperature states and temperature thresholds of various vehicles, thus forming the vehicle's temperature threshold relationship. This mapping relationship between the temperature states and temperature thresholds of various vehicles can be established based on battery temperature data, ambient temperature data, and the relationship between the temperature data of each vehicle and its static state for different battery models and usage scenarios. This ensures that the established mapping relationship adapts to various vehicles, different climates, and regional environmental differences, guaranteeing the accuracy of the determined corrected temperature threshold.

[0128] In this embodiment, the cloud server determines the vehicle's static state based on the temperature difference relationship during the vehicle's hibernation time, making the determination more reliable. Furthermore, the determination result is compared with the local static flag in the BMS to verify the local determination result, thus avoiding the limitations of local BMS determination. Additionally, when the determination result does not match the static state determined locally by the BMS, a temperature difference threshold relationship for the vehicle is generated and sent to the BMS for temperature threshold correction, making subsequent static determinations by the BMS more accurate.

[0129] In one embodiment, the process of the cloud server generating the temperature difference threshold relationship of the vehicle includes: determining the compensation error type of the BMS based on the sleep time and the temperature change rate per unit time; determining the corrected temperature threshold of the vehicle based on the compensation error type and the temperature change values ​​of multiple batteries under multiple power outages; and determining the temperature difference range and the corrected temperature threshold as the temperature difference threshold relationship.

[0130] The mismatch between the static status determination result of the cloud server and the static sign of the vehicle can be divided into two situations: the static status determination result of the cloud server is non-static, while the static sign of the vehicle is static; and the static status determination result of the cloud server is static, while the static sign of the vehicle is non-static.

[0131] If the cloud server determines the vehicle's static state as non-static and the vehicle's static flag is static, then if the battery's sleep time during the most recent power-down to power-up period is less than 1 hour, the BMS compensation error type is determined to be a mis-repair. If the cloud server determines the vehicle's static state as static and the vehicle's static flag is non-static, then if the battery's sleep time during the most recent power-down to power-up period is greater than or equal to 1 hour, the BMS compensation error type is determined to be a missed repair. This 1 hour is a critical sleep time value. A mis-repair occurs when the battery is briefly de-energized, and the BMS uses an excessively low temperature threshold, mistakenly classifying the vehicle as static. The temperature threshold needs to be increased. Therefore, for the mis-repair error type, the median, average, or maximum value of multiple battery temperature changes during multiple power-down periods is determined as the corrected temperature threshold. A missed repair occurs when the battery is de-energized for a long period, and the BMS uses an excessively high temperature threshold, causing a situation that should have been classified as static to be missed. The temperature threshold needs to be lowered. Therefore, for the missed repair error type, the minimum value of multiple battery temperature changes during multiple power-down periods is determined as the corrected temperature threshold.

[0132] In addition, the temperature change rate per unit time reflects the temperature drop per hour. If the temperature change rate per unit time exceeds the reasonable range under static conditions, such as the rate being stable at 0.5-2℃ / h under static conditions and fluctuating greatly under non-static conditions, this can help verify the accuracy of the error type determination of incorrect repair / missed repair.

[0133] The cloud server can also send the unit time temperature change rate in the hibernation time temperature difference relationship table to the BMU, so that the BMS can verify the accuracy of the local hibernation time determination based on the unit time temperature change rate. For example, when the BMS determines the hibernation time to be 61 minutes, it needs to check the actual temperature drop rate and the unit time temperature change rate sent by the cloud server. If the error is within a certain range, it is considered to be within the reasonable range, thereby ensuring the reliability of the time compensation of the BMS.

[0134] Based on the determined corrected temperature threshold of the vehicle, the cloud server determines the correspondence between the temperature difference range to which the vehicle's temperature difference belongs and the corrected temperature threshold as the temperature difference threshold relationship of the vehicle.

[0135] In this embodiment, the cloud server combines the sleep time and the temperature change rate per unit time to determine the type of compensation error, accurately locate the root cause of the error, provide a clear direction for threshold correction, and avoid blind adjustment; and determine the correction temperature threshold based on the error type and the battery temperature change value of the vehicle in multiple historical power outage cycles. Multiple sets of data support make the correction result fit the long-term temperature change characteristics of the vehicle, and improve the accuracy of temperature threshold correction.

[0136] like Figure 7 As shown in the diagram, this application embodiment provides a flowchart of a time compensation method executed by a cloud server. In this embodiment, when the cloud server detects that the vehicle's RTC flag is activated, it determines that the vehicle has an RTC fault. Then, it calculates the vehicle's battery's lowest temperature T0 during the 10 charge-discharge cycles before the vehicle's last power-off, the average cell temperature Tlast at the time of the last power-off, and the average cell temperature Tagv at the time of the current power-on. Furthermore, it determines the absolute value of the difference between Tlast and T0 as the battery temperature difference, and the absolute value of the difference between Tlast and Tagv as the battery temperature change value. Based on this battery temperature difference, the battery temperature change value, and the time interval between the last power-off and the current power-on, the cloud server determines the battery's sleep time and establishes the sleep time-temperature difference relationship for the vehicle. Then, the cloud server determines the temperature threshold of the temperature range to which the vehicle belongs based on the vehicle's sleep time temperature difference relationship and the vehicle's current temperature threshold. If the battery temperature change is greater than or equal to the temperature threshold, the vehicle is determined to be in a static state. This static state determination result is further compared with the vehicle's static indicator. If the static state determination result does not match the vehicle's static indicator, it is determined that the BMS time compensation has been incorrectly repaired. If the battery temperature change is less than the temperature threshold, the vehicle is determined to be in a non-static state. Furthermore, if the static state determination result does not match the vehicle's static indicator, it is determined that the BMS time compensation has been missed.

[0137] For cases of incorrect or missed repairs, the cloud server continues to determine the corrected temperature threshold and sends the corrected temperature threshold and its corresponding temperature difference range to the BMS so that the BMS can update its local temperature threshold. If, after the cloud server sends the corrected temperature threshold to the BMS and receives a successful correction response from the BMS, the static state of the vehicle reassessed by the cloud server is still inconsistent with the static flag retransmitted locally by the BMS, the BMS needs to be notified to update the content of the locally configured time compensation method. This means instructing the BMS to upgrade its software package to update the time compensation method. Specifically, if the cloud server finds that the vehicle's static flag is set when comparing the static state determination result with the vehicle's static flag, it determines that the time compensation on the BMS side is not performing correctly and can request the BMS to retransmit the vehicle's static flag. If the vehicle's static flag is still set after the retransmission, the cloud server also needs to instruct the BMS to upgrade its software package to notify the BMS to update the configuration of the time compensation method. In this way, if the temperature threshold still does not match after the update or the static flag is abnormal, the BMS will be triggered to update the content of the time compensation method, which will solve the problem of invalid temperature threshold adjustment, continuously ensure the effectiveness of the time compensation method, and ensure the reliable operation of BMS functions in RTC failure scenarios.

[0138] In this embodiment of the application, the process by which the cloud server sends a corrected temperature threshold to the BMS, and the BMS updates its local temperature difference threshold relationship based on the received corrected temperature threshold, can be implemented in the following way:

[0139] The cloud server sends the temperature threshold parameter value and calibration status identifier parameter value corresponding to the target temperature difference range to the BMU through a dedicated communication message for temperature threshold update. The temperature threshold parameter value corresponding to the target temperature difference range is used by the BMS to update the temperature threshold value of the target temperature difference range stored locally, and the calibration status identifier parameter value is used to distinguish the updates sent to the BMS at different times.

[0140] The BMS terminal detects whether the parameter value of the temperature threshold corresponding to the target temperature difference range is valid.

[0141] If the parameter value of the temperature threshold corresponding to the target temperature difference range is valid on the BMS side, and the calibration status identifier parameter value is different from the calibration status identifier parameter value sent by the cloud server last time, the temperature threshold of the target temperature difference range stored locally will be set to the parameter value of the temperature threshold corresponding to the target temperature difference range sent by the cloud server.

[0142] The BMS sends threshold feedback parameters and status feedback parameters to the cloud server through the BMU;

[0143] If the threshold feedback parameter matches the temperature threshold value corresponding to the target temperature difference range, and the status feedback parameter matches the calibration status identifier parameter value, the cloud server determines that the BMS has successfully updated the temperature threshold corresponding to the target temperature difference range.

[0144] The following example uses the temperature threshold update for a temperature difference range of T≤20℃ as an example:

[0145] Temperature threshold updates for the temperature difference range T≤20℃:

[0146] Cloud Server: The cloud server sends the R2U_TheFirstTempDropthre and R2U_RTCCompsat parameters to the BMU via a dedicated communication message 0x0108FFFE. The R2U_TheFirstTempDropthre parameter must be a valid value (not 0x00), and the value of the R2U_RTCCompsat parameter must not be equal to the value sent to the BMU at the previous moment. When the cloud server receives the U2R_TheFirstTempDropthre and U2R_RTCCompensation_FB returned by the BMU, and the value of U2R_TheFirstTempDropthre is equal to the value of R2U_TheFirstTempDropthre and the value of U2R_RTCCompensation_FB are equal to the value of R2U_RTCCompsat, the cloud server considers that the BMS has successfully updated the temperature threshold corresponding to the temperature difference range of T≤20℃ and records it.

[0147] BMS: When the BMU receives a valid R2U_TheFirstTempDropthre value sent by the cloud server via DCAN and R2U_RTCCompsat is not equal to the previous value, it sets the temperature threshold (ScRTCR_DeltaTemp) for the temperature difference ≤20℃ range (|ScRTCR_LastTenCycleMinTempInit-ScRTCR_LastShtdnAvgTimeInit|≤20) to the value of R2U_TheFirstTempDropthre; and feeds back U2R_TheFirstTempDropthre and U2R_RTCCompensation_FB to the cloud server, where the value of U2R_TheFirstTempDropthre is the value of R2U_TheFirstTempDropthre and the value of U2R_RTCCompensation_FB is the value of R2U_RTCCompsat.

[0148] Similarly, if the temperature threshold updates correspond to temperature difference ranges of 20 < T ≤ 40℃ and T > 40℃, the corresponding identifiers representing these temperature difference ranges in the parameters can be modified. For example, the temperature difference range of T ≤ 20℃ is identified as "First" in the parameters, the range of 20 < T ≤ 40℃ can be identified as "Second," and the range of T > 40℃ can be identified as "Third." Of course, this identification method is just an example; other methods can be used to identify different temperature difference ranges, as long as the parameters for different temperature difference ranges can be distinguished.

[0149] Among them, the valid value range of R2U_RTCCompsat is 0~99.

[0150] In this embodiment, the cloud server sends out correction thresholds according to three temperature difference ranges via dedicated messages. After receiving the messages, the BMS terminal sends back confirmation parameters, forming a closed-loop update mechanism from sending to execution to feedback, ensuring that the temperature threshold updates are accurately implemented.

[0151] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0152] Based on the same inventive concept, this application also provides a time compensation device for implementing the time compensation method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more time compensation device embodiments provided below can be found in the limitations of the time compensation method described above, and will not be repeated here.

[0153] In one embodiment, this application provides a time compensation device, the device comprising:

[0154] The relationship acquisition module is used to acquire the temperature difference threshold relationship, which includes the correspondence between temperature difference range and temperature threshold. The temperature difference range represents the degree to which the temperature of the battery deviates from the reference temperature during the last power-off, and the temperature threshold represents the amount of temperature change of the battery during the resting time from power-off to power-on in the corresponding temperature difference range. The compensation module is used to compensate the static dormancy time of the battery according to the temperature difference threshold relationship.

[0155] In one embodiment, the device further includes: a temperature data determination module, configured to determine the temperature difference between the battery's temperature during the vehicle's last power-off and a reference temperature; and to determine the temperature change value of the battery from the vehicle's last power-off to the current power-on; the compensation module includes: a threshold determination unit, configured to obtain a corresponding temperature threshold in a temperature difference threshold relationship based on the temperature difference range to which the temperature difference belongs; a sleep time determination unit, configured to determine the battery's static sleep time based on the temperature threshold and the temperature change value; and a compensation unit, configured to compensate the RTC based on the static sleep time.

[0156] In one embodiment, the sleep time determination unit is further configured to determine the static sleep time as a first compensation value when the temperature change value is greater than or equal to a temperature threshold, the first compensation value representing the shortest duration required for the BMS to perform the battery static management function, the shortest duration being greater than 0; or to determine the static sleep time as 0 when the temperature change value is less than the temperature threshold or when the temperature change value falls under other circumstances; other circumstances refer to any situation other than the temperature change value being greater than or equal to the temperature threshold and the temperature change value being less than the temperature threshold.

[0157] In one embodiment, the time compensation device further includes a static synchronization module, which is used to determine that the vehicle's stationary state is static when the static sleep time is determined to be a first compensation value, and to notify the cloud server so that the cloud server can verify the vehicle's stationary state.

[0158] In one embodiment, the temperature data determination module includes: a first temperature acquisition unit, configured to acquire a first average temperature of multiple cells of the battery at the time of the last power-off; a reference temperature acquisition unit, configured to acquire a reference temperature; the reference temperature is the lowest temperature under the most recent multiple complete charge-discharge cycles before the last power-off; and a temperature difference determination unit, configured to determine the temperature difference between the battery temperature at the time of the last power-off in the vehicle and the reference temperature based on the temperature difference between the first average temperature and the reference temperature.

[0159] In one embodiment, the temperature data determination module includes: a second temperature acquisition unit, configured to acquire a first average temperature of multiple cells of the battery when it was last powered off, and to acquire a second average temperature of multiple cells when it is currently powered on; and a temperature change value determination unit, configured to determine the absolute value of the difference between the first average temperature and the second average temperature as the temperature change value.

[0160] In one embodiment, this application provides a time compensation device, the device comprising:

[0161] The relationship generation module is used to generate the temperature difference threshold relationship of the vehicle. The temperature difference threshold relationship includes the correspondence between temperature difference range and temperature threshold. The temperature difference range represents the degree to which the temperature of the vehicle's battery deviates from the reference temperature during the last power-off. The temperature threshold represents the amount of temperature change of the battery during the resting time from power-off to power-on in the corresponding temperature difference range. The relationship sending module is used to send the temperature difference threshold relationship to the vehicle's BMS so that the BMS can compensate for the static dormancy time of the battery according to the temperature difference threshold relationship.

[0162] In one embodiment, the relationship generation module includes: a time-temperature difference relationship determination unit, used to determine the sleep time-temperature difference relationship of the vehicle under the current power outage according to the sleep time-temperature difference relationship table; the sleep time-temperature difference relationship table includes the sleep time-temperature difference relationship of the batteries of multiple RTC fault vehicles under the current power outage; a static state determination unit, used to determine the static state of the vehicle based on the sleep time-temperature difference relationship; and a relationship generation unit, used to generate a temperature difference threshold relationship of the vehicle when the static state determination result does not match the static flag of the vehicle; the static flag represents the static state of the vehicle as determined by the vehicle's BMS.

[0163] In one embodiment, the dormancy time temperature difference relationship includes the battery temperature change value and battery temperature difference corresponding to the current power outage of the vehicle; the static state determination unit includes: a temperature difference range determination subunit, used to determine the temperature difference range to which the vehicle's battery belongs under the current power outage based on the battery temperature difference; a temperature threshold determination subunit, used to obtain the current temperature threshold used by the BMS in the most recent determination of the vehicle's static state based on the temperature difference range to which the vehicle belongs; and a static state determination subunit, used to determine that the vehicle's static state is static when the battery temperature change value is greater than or equal to the current temperature threshold; and to determine that the vehicle's static state is non-static when the battery temperature change value is less than the current temperature threshold.

[0164] In one embodiment, the dormancy time temperature difference relationship also includes the vehicle's battery dormancy time and temperature change rate per unit time under the current power outage; the relationship generation unit includes: an error type determination subunit, used to determine the compensation error type of the BMS based on the dormancy time and temperature change rate per unit time; a correction threshold determination subunit, used to determine the vehicle's correction temperature threshold based on the compensation error type and multiple battery temperature change values ​​under multiple power outages; and a relationship determination subunit, used to determine the temperature difference range and correction temperature threshold as a temperature difference threshold relationship.

[0165] Each module in the aforementioned time compensation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the electronic device in hardware form or independent of it, or stored in the memory of the electronic device in software form, so that the processor can call and execute the operations corresponding to each module.

[0166] In one embodiment, this application provides a battery management system, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of any time compensation method provided in this application, which uses the battery management system as the execution subject.

[0167] In one embodiment, this application also provides a vehicle that includes the battery management system provided in the foregoing embodiments.

[0168] In one embodiment, this application also provides a cloud server, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in any of the time compensation methods provided in this application, which use a cloud server as the execution subject.

[0169] In addition to the memory and processor, the battery management system and cloud server in this embodiment may also include input / output (I / O) interfaces and communication interfaces. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interfaces are used for communicating with external terminals via a network. In some cases, the battery management system and cloud server may also include a display unit and an input device. The display unit is used to form a visually visible image and may be a display screen, a projection device, or a virtual reality imaging device. The display screen may be a liquid crystal display screen or an e-ink display screen, and the input device may be a keyboard, mouse, etc.

[0170] In one embodiment, this application also provides a vehicle service system, which includes the aforementioned battery management system and cloud server. Of course, in practical applications, the vehicle service system may also include other components and modules according to actual functional requirements, and this application does not limit this.

[0171] In one embodiment, this application also provides a non-transitory computer-readable storage medium including instructions, such as a memory including instructions, which can be executed by a processor of an electronic device to complete the steps in any of the time compensation methods provided in this application. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0172] In one embodiment, this application also provides a computer program product that, when executed by a processor, can implement the steps of any of the time compensation methods provided in this application. The computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, all or part of the methods described in this application can be implemented according to the processes or functions described in this application.

[0173] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application to facilitate a specific and detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims.Therefore, the scope of protection of this patent application shall be determined by the contents of the appended claims, and the specification and drawings may be used to interpret the contents of the claims.

Claims

1. A time compensation method, characterized in that, The method for compensating for the static sleep time of a battery in the event of a failure of its real-time clock (RTC) in a battery management system (BMS) includes: In the event of an RTC fault, the system requests a temperature threshold for the temperature range to which the battery temperature belongs when the vehicle was last powered off, based on the temperature range to which the battery temperature belongs when the vehicle was last powered off. The system also receives a temperature difference threshold relationship between the temperature range and the temperature threshold sent by the cloud server. The temperature range represents the degree to which the battery temperature deviates from the reference temperature when the vehicle was last powered off, and the temperature threshold represents the amount of temperature change required for the battery to reach a static state from power off to power on within the corresponding temperature range. Determine the temperature difference between the battery temperature at the last power-off point in the vehicle and the reference temperature, and determine the temperature change of the battery from the last power-off point in the vehicle to the current power-on point. Based on the temperature difference range to which the temperature difference belongs, the corresponding temperature threshold is obtained from the temperature difference threshold relationship; The static dormancy time of the battery is determined based on the temperature threshold and the temperature change value. The RTC is compensated based on the static sleep time.

2. The method according to claim 1, characterized in that, Determining the static sleep time of the battery based on the temperature threshold and the temperature change value includes: If the temperature change value is greater than or equal to the temperature threshold, the static sleep time is determined as a first compensation value, where the first compensation value represents the minimum duration required for the BMS to perform battery static management functions, and the minimum duration is greater than 0; or If the temperature change value is less than the temperature threshold or if the temperature change value falls under other circumstances, the static sleep time is determined to be 0; the other circumstances refer to any situation other than the temperature change value being greater than or equal to the temperature threshold and the temperature change value being less than the temperature threshold.

3. The method according to claim 2, characterized in that, The method further includes: If the static sleep time is determined to be the first compensation value, the vehicle's stationary state is determined to be static, and the cloud server is notified so that the cloud server can verify the vehicle's stationary state.

4. The method according to any one of claims 1-3, characterized in that, Determining the temperature difference between the battery's temperature during the previous power-off in the vehicle and a reference temperature includes: Obtain the first average temperature of multiple cells of the battery at the time of the last power-off; The reference temperature is obtained; the reference temperature is the lowest temperature under the most recent multiple complete charge-discharge cycles before the last power-off. The temperature difference between the battery's temperature during the first power-off in the vehicle and the reference temperature is determined based on the temperature difference between the first average temperature and the reference temperature.

5. The method according to any one of claims 1-3, characterized in that, Determining the temperature change of the battery from the last time the vehicle was powered off to the current time it was powered on includes: The first average temperature of the multiple cells of the battery at the last power-off time is obtained, and the second average temperature of the multiple cells at the current power-on time is obtained; The absolute value of the difference between the first average temperature and the second average temperature is determined as the temperature change value.

6. A time compensation method, used by a cloud server to assist in compensating for the static sleep time of the battery in the event of a failure of the real-time clock (RTC) of the battery management system (BMS), characterized in that, The method includes: Upon receiving the temperature difference range of the battery when the vehicle was last powered off, sent by the vehicle's BMS, a temperature difference threshold relationship for the vehicle is generated. The temperature difference threshold relationship includes the correspondence between the temperature difference range and the temperature threshold. The temperature difference range represents the degree to which the temperature of the vehicle's battery deviates from the reference temperature when it was last powered off, and the temperature threshold represents the amount of temperature change required for the battery to reach a static state from power off to power on within the corresponding temperature difference range. The temperature difference threshold relationship is sent to the vehicle's BMS so that the BMS can determine the temperature difference between the battery's temperature during the vehicle's last power-off and the reference temperature, as well as the temperature change value of the battery from the vehicle's last power-off to the current power-on. Based on the temperature difference range to which the temperature difference belongs, the corresponding temperature threshold is obtained from the temperature difference threshold relationship. Based on the temperature threshold and the temperature change value, the static sleep time of the battery is determined, and the RTC is compensated based on the static sleep time.

7. The method according to claim 6, characterized in that, The generated temperature difference threshold relationship for vehicles includes: The dormancy time temperature difference relationship of the vehicle under the current power outage is determined according to the dormancy time temperature difference relationship table; the dormancy time temperature difference relationship table includes the dormancy time temperature difference relationship of the battery of multiple RTC fault vehicles under the current power outage; Based on the temperature difference relationship during the dormancy period, the stationary state of the vehicle is determined; If the result of the static state determination does not match the static flag of the vehicle, a temperature difference threshold relationship of the vehicle is generated; the static flag represents the static state of the vehicle as determined by the BMS of the vehicle.

8. The method according to claim 7, characterized in that, The dormancy time temperature difference relationship includes the battery temperature change value and battery temperature difference corresponding to the current power outage of the vehicle; Determining the stationary state of the vehicle based on the temperature difference relationship during the dormancy period includes: The temperature range of the vehicle's battery under the current power outage is determined based on the battery temperature difference. Based on the temperature difference range, obtain the current temperature threshold used by the BMS in the most recent determination of the vehicle's stationary state. If the battery temperature change value is greater than or equal to the current temperature threshold, the vehicle's stationary state is determined to be static. If the battery temperature change is less than the current temperature threshold, the vehicle's stationary state is determined to be non-static.

9. The method according to claim 8, characterized in that, The dormancy time temperature difference relationship also includes the vehicle's battery dormancy time and temperature change rate per unit time under the current power outage. The generation of the temperature difference threshold relationship for the vehicle includes: The compensation error type of the BMS is determined based on the sleep time and the temperature change rate per unit time. Based on the compensation error type and the multiple battery temperature change values ​​of the vehicle under multiple power outages, the corrected temperature threshold of the vehicle is determined. The temperature difference range and the corrected temperature threshold are determined to be the temperature difference threshold relationship.

10. A battery management system, characterized in that, The battery management system includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method of any one of claims 1 to 5.

11. A vehicle, characterized in that, The vehicle includes the battery management system as described in claim 10.

12. A cloud server, characterized in that, The cloud server includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method of any one of claims 6 to 9.

13. A vehicle service system, characterized in that, The vehicle service system includes the battery management system as described in claim 10 and the cloud server as described in claim 12.

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