Battery state of charge calibration method, apparatus, medium, terminal, and program product

Abstract

The application provides a battery state of charge calibration method, device, medium, terminal and program product, the method comprises: obtaining the first full charge calibration compensation value and the second full charge calibration compensation value of each full charge state, after the first full charge is completed, if the next charging meets the calibration precondition and the single highest voltage of the current charging state reaches the virtual voltage of the preset virtual point, the state of charge compensation value is calculated according to the compensation formula, and whether the state of charge compensation value is in the allowed calibration range is judged, if yes, the further calibration is executed according to the preset calibration formula, if not, it is ended; if the calibration precondition is met, the single highest voltage does not reach the virtual voltage and the actual state of charge value reaches the virtual state of charge value, then the calibration is carried out according to the preset retention strategy until the single highest voltage reaches the virtual voltage. The application can realize the state of charge calibration under the long time unfull charging condition, and reduces the dependence on open circuit voltage data.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a battery state of charge calibration method, device, medium, terminal and program product. Background Technology

[0002] Accurate estimation of battery State of Charge (SOC) is crucial for battery lifespan, safety, and the driving range of electric vehicles. Currently, SOC estimation is primarily based on battery voltage and charging / discharging current, combined with appropriate algorithms. Mainstream algorithms can be broadly categorized into three types: ampere-hour integration, Kalman filtering, and neural network methods. Among these, the ampere-hour integration method obtains the real-time battery SOC value by calculating the integral of the charging / discharging current over time. Due to its simplicity and ease of implementation, it has been widely used in practice. For lithium iron phosphate batteries, the ampere-hour integration method and its derivative algorithms (such as ampere-hour integration + open-circuit voltage method, ampere-hour integration + Kalman filtering method) are typically used for SOC estimation. These methods update the battery SOC value in real time through current integration and calibrate at the beginning and end of the entire SOC range by incorporating factors such as ambient temperature, current magnitude, and battery aging.

[0003] However, due to the long plateau period of lithium iron phosphate batteries, the accuracy of SOC estimation using the ampere-hour integration method requires frequent full-charge calibration. Otherwise, the accumulated error from integration will gradually increase, leading to a larger and larger SOC estimation error. Currently, new energy heavy-duty trucks use battery swapping technology, but its application scenarios cannot meet the requirement of frequent full-charge calibration of the battery's SOC. For example, when battery swapping stations are built in mountainous operating scenarios, there are long downhill conditions. When vehicles go downhill, they can use regenerative energy to charge the battery. If the battery is frequently fully charged, the energy utilization efficiency in this condition will decrease. When the load rate of the battery swapping station is relatively high, vehicles are queuing to replace batteries, while the charging current at the end of the charging process is small, and the charging time is relatively long. To reduce vehicle waiting time, charging is generally stopped at 95%. If the power battery is not fully charged for a long time, the estimated SOC error will gradually increase, causing the vehicle to break down prematurely, affecting the assessment of battery health status and the optimization of charging and discharging strategies, and thus affecting battery life.

[0004] Furthermore, in practical applications, when using the ampere-hour integration + OCV (Open Circuit Voltage) method for SOC calibration, the calibration is mainly concentrated at the SOC front end (0%~20%) and the end end (96%~100%). Front-end SOC correction requires a certain settling time, and since heavy-duty trucks undergoing battery swapping are constantly in operation, it is difficult to meet the low-end SOC settling conditions. Therefore, SOC calibration for new energy heavy-duty trucks is basically concentrated at the charging end. This charging end calibration uses voltage to calibrate SOC and heavily relies on SOC-OCV data. If there is a deviation in the OCV data, it will affect the accuracy of SOC calibration. At the same time, the power batteries of new energy heavy-duty trucks are usually composed of hundreds of individual cells, and there are voltage differences between the individual cells. However, the existing SOC calibration does not take into account the influence of the individual cell voltage differences, and using only OCV calibration may exacerbate the SOC estimation error.

[0005] Therefore, it is necessary to provide a battery state of charge calibration method, apparatus, medium, terminal, and program product to solve the above-mentioned problems existing in the prior art. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a battery state of charge calibration method, device, medium, terminal and program product to solve the technical problem of the prior art relying on full charge and OCV data for SOC calibration.

[0007] To achieve the above and other related objectives, the first aspect of this application provides a battery state-of-charge calibration method, comprising:

[0008] Determine whether the first full charge is completed. If the first full charge is not completed, return a prompt message to end the calibration. If the first full charge is completed, obtain the first full charge calibration compensation value and the second full charge calibration compensation value calculated in the first full charge state and proceed to the following calibration steps.

[0009] Obtain the highest voltage data of a single cell during this charging state;

[0010] If the calibration prerequisites are met and the highest voltage data of the acquired individual cell reaches the virtual voltage of the preset virtual point, then the state of charge compensation value is calculated based on the virtual state of charge value of the virtual point, the first full charge calibration compensation value and the second full charge calibration compensation value of the first full charge state. If the calculated state of charge compensation value is within the allowable calibration range according to the preset judgment conditions, then further calibration is performed according to the preset calibration formula to obtain the calibrated state of charge value. If the calculated state of charge compensation value is not within the allowable calibration range according to the preset judgment conditions, then the end information is returned.

[0011] If the pre-calibration conditions are met, the highest voltage data of a single cell does not reach the virtual voltage and the actual state of charge value in the current state reaches the virtual state of charge value, then calibration is performed according to the preset holding strategy until the highest voltage data of the single cell reaches the virtual voltage.

[0012] If the current charging state reaches full charge, the first full charge calibration compensation value and the second full charge calibration compensation value for this full charge state are calculated and updated for use in the virtual point charge state calibration during the next charging.

[0013] In some embodiments of the first aspect of this application, the calculation process of the first full-charge calibration compensation value and the second full-charge calibration compensation value at each full-charge state includes: when the battery is charged to a virtual point, obtaining the first state of charge value and the first cumulative charging capacity at the current moment; when the battery is charged to a full-charge state, obtaining the second cumulative charging capacity at the full-charge moment, and calculating the second state of charge value based on the first cumulative charging capacity and the second cumulative charging capacity; calculating the first state of charge deviation value and the second state of charge deviation value based on the second state of charge value, the first state of charge value and the virtual state of charge value of the virtual point; calculating and updating the first full-charge calibration compensation value and the second full-charge calibration compensation value based on the calculated first state of charge deviation value and the second state of charge deviation value, and storing them.

[0014] In some embodiments of the first aspect of this application, the specific process of calculating and updating the first full-charge calibration compensation value and the second full-charge calibration compensation value based on the calculated first state-of-charge deviation value and the second state-of-charge deviation value, and storing them, includes: if the absolute value of the first state-of-charge deviation value is less than or equal to the first error, then the first full-charge calibration compensation value is zero, and the second full-charge calibration compensation value is calculated based on the number of times the charge was not fully charged and the second state-of-charge deviation value; if the absolute value of the calculated second full-charge calibration compensation value is less than or equal to the second error, then the second full-charge calibration compensation value is set to zero; if the absolute value of the first state-of-charge deviation value is between the first error and the third error, then the first full-charge calibration compensation value is calculated based on the first state-of-charge deviation value and the first error; if the first state-of-charge deviation value is between the negative number of the third error and the negative number of the first error, then the first full-charge calibration compensation value is calculated based on the first state-of-charge deviation value and the first error; if the absolute value of the first state-of-charge deviation value exceeds the third error, then the system switches to manual calibration mode.

[0015] In some embodiments of the first aspect of this application, the specific process of calibrating according to a preset holding strategy until the highest voltage data of a single cell reaches the virtual voltage is as follows: obtaining the state of charge value at the current moment and the state of charge value at the next moment, and calculating the change in state of charge value of both; multiplying the change in state of charge value by a holding coefficient to perform holding calibration until the highest voltage data of a single cell reaches the virtual voltage.

[0016] In some embodiments of the first aspect of this application, if the difference between the actual state of charge and the virtual state of charge is less than or equal to the fourth error, the retention coefficient is the first retention coefficient; if the difference between the actual state of charge and the virtual state of charge is between the fourth error and the fifth error, the retention coefficient is the second retention coefficient; if the difference between the actual state of charge and the virtual state of charge is greater than the fifth error, the retention coefficient is the third retention coefficient.

[0017] In some embodiments of the first aspect of this application, the virtual voltage of the virtual point is preset based on the current, the lowest temperature of the single cell, and the number of cycles.

[0018] To achieve the above and other related objectives, a second aspect of this application provides a battery state of charge calibration device, comprising:

[0019] The first full charge judgment module is used to determine whether the first full charge is completed. If the first full charge is not completed, a prompt message to end the calibration is returned. If the first full charge is completed, the first full charge calibration compensation value and the second full charge calibration compensation value calculated in the first full charge state are obtained and the following calibration steps are entered.

[0020] The calibration module is used to acquire the highest voltage data of a single cell during the current charging state. If the calibration preconditions are met and the acquired highest voltage data of a single cell reaches the virtual voltage of a preset virtual point, the state of charge compensation value is calculated based on the virtual state of charge value of the virtual point, the first full-charge calibration compensation value and the second full-charge calibration compensation value of the first full-charge state. If the calculated state of charge compensation value is within the allowable calibration range according to the preset judgment conditions, further calibration is performed according to the preset calibration formula to obtain the calibrated state of charge value. If the calculated state of charge compensation value is not within the allowable calibration range according to the preset judgment conditions, the end information is returned. If the calibration preconditions are met, the highest voltage data of a single cell does not reach the virtual voltage and the actual state of charge value in the current state reaches the virtual state of charge value, calibration is performed according to the preset holding strategy until the highest voltage data of a single cell reaches the virtual voltage.

[0021] The update module is used to calculate and update the first full charge calibration compensation value and the second full charge calibration compensation value when the current charging state reaches the full charge state, so as to be used for virtual point charge state calibration during the next charging.

[0022] To achieve the above and other related objectives, a third aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method.

[0023] To achieve the above and other related objectives, a fourth aspect of this application provides a computer program product comprising computer program code that, when executed on a computer, causes the computer to implement the method.

[0024] To achieve the above and other related objectives, a fifth aspect of this application provides an electronic terminal, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program to implement the method.

[0025] As described above, the battery state-of-charge calibration method, apparatus, medium, terminal, and program product of this application have the following beneficial effects:

[0026] The system calculates a first full-charge calibration compensation value and a second full-charge calibration compensation value during each full charge. These values ​​are then used to calibrate the state of charge (SOC) when the virtual charging point is reached during the next charge. Specifically, provided that the pre-calibration conditions are met, if the highest voltage data of the acquired individual cell reaches the virtual voltage of the preset virtual point, then the SOC compensation value is calculated based on the virtual SOC value of the virtual point and the first and second full-charge calibration compensation values ​​calculated during the previous full charge. Furthermore, the system determines whether the calculated SOC compensation value is within the allowable calibration range based on preset judgment conditions. If it is within the allowable calibration range... If the calibration is not within the allowable calibration range, the calibration will be further performed according to the preset calibration formula to obtain the calibrated state of charge value. If the value is not within the allowable calibration range, the end information will be returned. If the highest voltage data of the obtained single cell does not reach the virtual voltage but the actual state of charge value under the current state reaches the virtual state of charge value, the calibration will be performed according to the preset holding strategy until the highest voltage data of the single cell reaches the virtual voltage. When the virtual voltage is reached, the calibration will be performed according to the above calibration steps. This application can realize the state of charge calibration under the condition of long-term uncharged operation and reduce the dependence on open circuit voltage data, thereby improving the accuracy of state of charge calibration. Attached Figure Description

[0027] Figure 1 The diagram shown is a flowchart illustrating a battery state-of-charge calibration method according to an embodiment of this application.

[0028] Figure 2 The diagram shown illustrates the working principle of a battery state-of-charge calibration method in one embodiment of this application.

[0029] Figure 3 The diagram shown is a block diagram of a battery state of charge calibration device according to an embodiment of this application.

[0030] Figure 4 The diagram shown is a structural schematic of an electronic terminal according to an embodiment of this application. Detailed Implementation

[0031] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0032] In the embodiments of this application, terms such as "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, "first XX" and "second XX" are merely used to distinguish different XXs and do not limit their order. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or execution order, and that "first" and "second" do not necessarily imply that they are different.

[0033] It should be noted that, in the embodiments of this application, the words "exemplary" or "for example" indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0034] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0035] Before providing a further detailed description of the present invention, the nouns and terms used in the embodiments of the present invention are explained, and the nouns and terms used in the embodiments of the present invention are subject to the following interpretations:

[0036] <1> Cycle: This is the most critical laboratory indicator for measuring battery life. A complete "cycle" is usually defined as the process of discharging the battery from a fully charged state to a specified cutoff charge and then fully charging it again.

[0037] <2> EEPROM (Electrically Erasable Programmable Read Only Memory) is a non-volatile memory that does not lose data even when power is off. It uses electrical signals to erase and write data and is widely used in embedded systems, IoT devices, and other scenarios that require storing variable data.

[0038] <3> State of Health (SOH) data is a core indicator for measuring the degree of battery degradation and remaining lifespan. Its accurate assessment directly affects the operational safety of new energy equipment, range prediction, and the formulation of operation and maintenance strategies.

[0039] <4> Battery Management System (BMS): Responsible for monitoring the status of the battery pack (such as voltage, current, and temperature), balancing the cells, estimating the remaining charge (SOC), and protecting battery safety.

[0040] To facilitate understanding of the embodiments of this application, in conjunction with Figure 1 and Figure 2 Detailed explanation. Figure 1 A flowchart illustrating a battery state of charge calibration method according to an embodiment of the present invention is shown. Figure 1 A schematic diagram illustrating the working principle of a battery state-of-charge calibration method according to an embodiment of the present invention is shown. The battery state-of-charge calibration method in this embodiment includes the following steps:

[0041] Step S11: Determine whether the first full charge is completed. If the first full charge is not completed, return a prompt message indicating the end of calibration. If the first full charge is completed, obtain the first full charge calibration compensation value and the second full charge calibration compensation value calculated under the first full charge state and proceed to the following calibration steps.

[0042] It should be noted that the first full charge of the battery is a prerequisite for the battery state of charge calibration method of this application. Subsequent calibration steps will only be triggered after the first full charge is completed. If the first full charge is not completed, a prompt message indicating the end of calibration will be returned.

[0043] Step S12: Obtain the highest voltage data of a single cell under the current charging state; if the calibration preconditions are met and the obtained highest voltage data of a single cell reaches the virtual voltage of a preset virtual point, then calculate the state of charge compensation value based on the virtual state of charge value of the virtual point, the first full charge calibration compensation value and the second full charge calibration compensation value of the first full charge state; if the calculated state of charge compensation value is within the allowable calibration range according to the preset judgment conditions, then perform further calibration according to the preset calibration formula to obtain the calibrated state of charge value; if the calculated state of charge compensation value is not within the allowable calibration range according to the preset judgment conditions, then return the end information; if the calibration preconditions are met, the highest voltage data of a single cell does not reach the virtual voltage and the actual state of charge value under the current state reaches the virtual state of charge value, then perform calibration according to the preset holding strategy until the highest voltage data of a single cell reaches the virtual voltage.

[0044] In some embodiments of this application, the virtual voltage of the virtual point is preset based on the current, the lowest temperature of the single cell, and the number of cycles.

[0045] Actual operational data from vehicle lithium batteries shows that as the number of battery cycles increases, the virtual voltage at virtual points decreases. A significant change has occurred. Virtual voltage. The preconditions are obtained, and the virtual voltages corresponding to different number of cycles under the preconditions are obtained. As shown in Table 1 below:

[0046] Table 1. Prerequisites for obtaining virtual voltage corresponding to virtual points

[0047]

[0048] As shown in Table 1, under the conditions of a current of 0.5C ± 10 and a minimum cell temperature of 20°C or higher, the virtual voltages corresponding to different aging stages are obtained before the first cycle (<cycle 1). virtual1 Between the first and second cycle counts (cycle1~cycle2), the corresponding virtual voltage (V) is obtained. virtual2 After the second loop iteration, obtain the corresponding virtual voltage (V). virtual3 It should be noted that all data in Table 1 are laboratory data.

[0049] In some embodiments of this application, the calculation process of the first full-charge calibration compensation value and the second full-charge calibration compensation value at each full-charge state includes: when the battery is charged to a virtual point, obtaining the first state of charge value and the first cumulative charging capacity at the current moment; when the battery is charged to a full-charge state, obtaining the second cumulative charging capacity at the full-charge moment, and calculating the second state of charge value based on the first cumulative charging capacity and the second cumulative charging capacity; calculating the first state of charge deviation value and the second state of charge deviation value based on the second state of charge value, the first state of charge value, and the virtual state of charge value of the virtual point; calculating and updating the first full-charge calibration compensation value and the second full-charge calibration compensation value based on the calculated first state of charge deviation value and the second state of charge deviation value, and storing them.

[0050] In this embodiment, a full-charge calibration feedback is triggered each time the battery is fully charged, and a first full-charge calibration compensation value is calculated and output. Second full charge calibration compensation value This is used for calibration compensation of the virtual points during the next charging. The specific calculation process is as follows:

[0051] When the highest voltage data of a single cell during this charging state is greater than or equal to the virtual voltage of the virtual point... That is, when the battery is charged to a virtual point, the first state of charge value at that moment is recorded. (If this full charge is not the first full charge, then the first state of charge value is the value after virtual point calibration) and the first cumulative charging capacity. .

[0052] When the battery is fully charged, record the second cumulative charging capacity at that moment. And perform the conversion to the second state of charge value during the process from the virtual point to the fully charged state. The calculation formula is as follows:

[0053] ;Formula (1)

[0054] in, This refers to the battery's rated capacity. This is the battery's health status data.

[0055] Then based on the second state of charge value First state of charge value Virtual state of charge values ​​of virtual points The first state-of-charge deviation value is calculated based on the preset value. Second state of charge deviation value The specific calculation formulas are as follows:

[0056] ;Formula (2)

[0057] in, The theoretical state of charge value for the interval from the virtual point to the fully charged state is calculated using the following formula:

[0058] When the battery cycle count is ≤ 3, then:

[0059] ;Formula (3)

[0060] Here, cycle3 is the third cycle number, and cycle is the actual number of cycles the battery has undergone.

[0061] When the battery cycle count > cycle 3, at this time:

[0062] ;Formula (4)

[0063] Therefore, the first state of charge deviation value is calculated according to formulas (2), (3) and (4). It is the deviation value of the charged amount between the virtual point and the fully charged state.

[0064] Second state of charge deviation value This represents the deviation between the actual state of charge (SOC) value of a single cell after the highest voltage data reaches the virtual voltage and the virtual SOC value of the virtual point. The specific calculation formula is as follows:

[0065] ;Formula (5)

[0066] The first state of charge deviation value calculated according to the above formulas (2), (3) and (4) and the second state of charge deviation value calculated by formula (5) Calculate and update the first full-charge calibration compensation value. Second full charge calibration compensation value .

[0067] In some embodiments of this application, the specific process of calculating and updating the first full-charge calibration compensation value and the second full-charge calibration compensation value based on the calculated first state-of-charge deviation value and the second state-of-charge deviation value, and storing them, includes: if the absolute value of the first state-of-charge deviation value is less than or equal to the first error, then the first full-charge calibration compensation value is zero, and the second full-charge calibration compensation value is calculated based on the number of times the charge was not fully charged and the second state-of-charge deviation value; if the absolute value of the calculated second full-charge calibration compensation value is less than or equal to the second error, then the second full-charge calibration compensation value is set to zero; if the absolute value of the first state-of-charge deviation value is between the first error and the third error, then the first full-charge calibration compensation value is calculated based on the first state-of-charge deviation value and the first error; if the first state-of-charge deviation value is between the negative number of the third error and the negative number of the first error, then the first full-charge calibration compensation value is calculated based on the first state-of-charge deviation value and the first error; if the absolute value of the first state-of-charge deviation value exceeds the third error, then the system switches to manual calibration mode.

[0068] Specifically, when | When, it indicates virtual voltage The corresponding state of charge value is relatively accurate, and no compensation is needed in this case. That is, the first full charge calibration compensation value Under this premise, the second full-charge calibration compensation value is then calculated. The calculation is detailed below:

[0069] when When the actual state of charge value is small, the second full-charge calibration compensation value is adjusted accordingly. The specific calculation formula is as follows:

[0070] ;Formula (6)

[0071] when When the actual state of charge value is large, the second full-charge calibration compensation value is... The specific calculation formula is as follows:

[0072] ;Formula (7)

[0073] in, The first acceptable error is a fixed value. ; It is a constant; This represents the number of times the battery was not fully charged, stored in the BMS. The number of charges will be cleared after the battery is fully charged.

[0074] Formulas (6) and (7) are The control function is used to calculate the second full-charge calibration compensation value. When the error is small, the compensation value can be increased to speed up the actual SOC correction; when the error is large, the maximum compensation value can be limited to prevent erroneous calibration.

[0075] Existing SOC calibration schemes based on partial charge do not consider the number of times the battery has been partially charged. The number of partial charge cycles can cause varying degrees of deviation in SOC estimation accuracy; generally, the more partial charge cycles, the greater the error in SOC estimation. Therefore, in this embodiment, the number of partial charge cycles stored in the BMS is used as a calculation parameter to correct the SOC value, thereby improving the accuracy of SOC calibration.

[0076] In addition, to avoid increased state-of-charge estimation errors caused by overcalibration, the second full-charge calibration compensation value is adjusted. To impose restrictions, that is, when The absolute value is less than the second error When its value is 0.5%, Set to zero; no compensation will be performed at this time. The first full-charge calibration compensation value will then be... Second full charge calibration compensation value The maximum compensation is limited to the fourth error. Its value is 1%, which is for and Limit the scope.

[0077] Furthermore, when When this time, it indicates that the amount of charge received from the virtual location to the fully charged state is greater than [a certain value]. When the voltage reaches the pressure The actual state of charge value is lower afterward, at which point the first full charge calibration compensation value is lower. The calculation formula is as follows:

[0078] ;Formula (8)

[0079] in, The third error is 0.8%.

[0080] Furthermore, when When this occurs, it indicates that the amount of charge received from the virtual location to the fully charged state is less than [a certain value]. When the voltage reaches The actual state of charge value is too high, at which point the first full charge calibration compensation value is... The calculation formula is as follows:

[0081] ;Formula (9)

[0082] Furthermore, when | When, it indicates The corresponding actual state of charge value deviates significantly, requiring manual analysis to determine the cause. In this case, the first full-charge calibration compensation value should be cleared. Second full charge calibration compensation value .

[0083] The calibration process is explained using the charging phase between the first full charge and the second full charge as an example. The calibration compensation value for the first full charge is shown in the diagram. Second full charge calibration compensation value This data is calculated based on the initial full charge. After the initial full charge, when the highest voltage data of a single cell reaches the virtual voltage of the virtual point and meets the preconditions for enabling virtual point state of charge (SOC) calibration, virtual point SOC calibration is initiated. Specifically, the preconditions are: normal charging without any fault exiting charging; stable charging current, specifically, the charging current is stable within the range of 0.5C±10A for 10 seconds; the lowest temperature of a single cell is greater than 15℃ and the highest temperature of a single cell is less than 50℃; if the SOC starts above 85% during charging, virtual point calibration is not performed for this charge. Under the premise of meeting the preconditions, when the highest voltage data of a single cell during this charging phase reaches the virtual voltage, virtual point calibration is performed based on the difference between the actual SOC value and the virtual SOC value. The specific calibration process is as follows:

[0084] First, perform a full-charge calibration compensation, with the state-of-charge compensation value... The compensation formula is as follows:

[0085] ;Formula (10)

[0086] The state of charge compensation value calculated according to formula (10) is compared with the preset judgment conditions to determine whether it is within the allowable calibration range. If it is within the allowable calibration range, further calibration is performed according to the calibration formula; if it is not within the allowable calibration range, the end information is returned, as follows:

[0087] when or If the error is too large, it indicates that human intervention is needed to analyze the cause. Further calibration is required.

[0088] when If the error is small, it means that an error is permissible and is not acceptable. Further calibration is required.

[0089] when If the error is within the allowable calibration range, further calibration should be performed. The calibration formula is as follows:

[0090] ;Formula (11)

[0091] in, The state of charge value after further calibration.

[0092] when If the error is within the allowable calibration range, further calibration should be performed. The calibration formula is as follows:

[0093] ;Formula (12)

[0094] when If the error is within the allowable calibration range, then the state of charge (SOC) value needs to be calibrated downwards. Since the SOC value cannot be calibrated downwards during charging, this calibration will be performed at the start of the next discharge. The calibration formula is as follows:

[0095] ;Formula (13)

[0096] in, , , , , The preset threshold, ; ; ; ; ; This is the state of charge value at the start of discharge; The cumulative charging capacity at the end of the charging process; This refers to the cumulative charging capacity when virtual point calibration is enabled.

[0097] If this charge is fully charged, or during this charging period If this happens, then no state of charge calibration will be performed at the start of the next discharge.

[0098] The calibration process between the first and second full charges, between the second and third full charges, between the third and fourth full charges, and so on, is the same as described above. For the sake of simplicity, it will not be repeated here.

[0099] In some embodiments of this application, the specific process of calibrating according to a preset holding strategy until the highest voltage data of a single cell reaches the virtual voltage is as follows: obtaining the state of charge value at the current moment and the state of charge value at the next moment, and calculating the change value of the state of charge of both; multiplying the change value of the state of charge by a holding coefficient to perform holding calibration until the highest voltage data of a single cell reaches the virtual voltage.

[0100] In some embodiments of this application, if the difference between the actual state of charge (SBC) and the virtual state of charge (VBC) is less than or equal to the fourth error, the retention coefficient is the first retention coefficient; if the difference between the SBC and the VBC is between the fourth error and the fifth error, the retention coefficient is the second retention coefficient; and if the difference between the SBC and the VBC is greater than the fifth error, the retention coefficient is the third retention coefficient.

[0101] Specifically, if, under the pre-calibration conditions, the highest voltage data of a single cell does not reach the virtual voltage, but the actual state of charge (SOC) value under the current state reaches the virtual SOC value, it indicates that the actual SOC value at this time... If the value is too high, calibration will be performed according to the preset holding strategy, specifically:

[0102] The change in state of charge between the current state of charge and the next state of charge is calculated at each time. Multiply by a retention factor This continues until the highest voltage of the individual cell reaches the virtual voltage. At this point, the hold strategy is discontinued, and the aforementioned virtual point calibration steps based on the first and second full-charge calibration compensation values ​​are performed. Hold coefficient. The system is dynamically adjusted based on the difference between the actual state of charge (SOC) value and the virtual SOC value, as follows:

[0103] when At this time, the coefficient is maintained. ;when At this time, the coefficient is maintained. ;when At this time, the coefficient is maintained. .in, The fifth error is 2%.

[0104] Step S13: If the current charging state reaches full charge, calculate and update the first full charge calibration compensation value and the second full charge calibration compensation value for the current full charge state, so as to be used for virtual point charge state calibration during the next charging.

[0105] Each time the battery is fully charged, a full charge calibration feedback is triggered, and the first full charge calibration compensation value is calculated and output. Second full charge calibration compensation value The system updates the value and stores it in the EEPROM for virtual point state of charge calibration during the next charge cycle.

[0106] The battery state-of-charge (SOC) calibration method provided in this application calculates a first full-charge calibration compensation value and a second full-charge calibration compensation value during each full charge. During the next charge, when the highest voltage of a single cell reaches the virtual voltage, these two values ​​are added to the actual SOC value to obtain a compensated SOC value. The compensated SOC value is then compared with the virtual SOC value, and the actual SOC value is recalibrated based on the deviation between the two, thus obtaining a calibrated SOC value. This calibration method fills the correction gap outside the front-end and back-end SOC correction intervals, reduces the dependence on OCV voltage accuracy, and weakens the impact of errors when virtual point calibration occurs using the cumulative capacity calibration method. It also reduces the dependence on full-charge correction and improves the accuracy of SOC estimation under multiple non-full-charge conditions.

[0107] Figure 3 This is a schematic block diagram of the battery state-of-charge calibration device provided in the embodiments of this application. Figure 3 As shown, the battery state-of-charge calibration device 300 includes:

[0108] The first full charge judgment module 301 is used to determine whether the first full charge is completed. If the first full charge is not completed, a prompt message to end the calibration is returned. If the first full charge is completed, the first full charge calibration compensation value and the second full charge calibration compensation value calculated in the first full charge state are obtained and the following calibration steps are entered.

[0109] The calibration module 302 is used to acquire the highest voltage data of a single cell during the current charging state. If the calibration preconditions are met and the acquired highest voltage data of a single cell reaches the virtual voltage of a preset virtual point, then the state of charge compensation value is calculated based on the virtual state of charge value of the virtual point, the first full-charge calibration compensation value and the second full-charge calibration compensation value of the first full-charge state. If the calculated state of charge compensation value is within the allowable calibration range according to the preset judgment conditions, then further calibration is performed according to the preset calibration formula to obtain the calibrated state of charge value. If the calculated state of charge compensation value is not within the allowable calibration range according to the preset judgment conditions, then the end information is returned. If the calibration preconditions are met, the highest voltage data of a single cell does not reach the virtual voltage and the actual state of charge value in the current state reaches the virtual state of charge value, then calibration is performed according to the preset holding strategy until the highest voltage data of a single cell reaches the virtual voltage.

[0110] The update module 303 is used to calculate and update the first full charge calibration compensation value and the second full charge calibration compensation value when the current charging state reaches the full charge state, so as to be used for virtual point charge state calibration during the next charging.

[0111] It should be understood that the specific process of each module performing the above-mentioned steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0112] It should also be understood that the module division in the embodiments of this application is illustrative and only represents a logical functional division; in actual implementation, there may be other division methods. Furthermore, the functional modules in the various embodiments of this application can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0113] Figure 4 This is a schematic block diagram of the electronic terminal provided in an embodiment of this application. Figure 4 As shown, the electronic terminal 400 includes at least one processor 401, a memory 402, at least one network interface 403, and a user interface 405. The various components in the electronic terminal 400 are coupled together via a bus system 404. It is understood that the bus system 404 is used to implement communication between these components. In addition to a data bus, the bus system 404 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in… Figure 4 The general will label all buses as bus systems.

[0114] The user interface 405 may include a monitor, keyboard, mouse, trackball, clicker, button, touchpad, or touch screen.

[0115] It is understood that memory 402 can be volatile memory or non-volatile memory, or both. Non-volatile memory can be read-only memory (ROM) or programmable read-only memory (PROM), used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM) and synchronous static random access memory (SSRAM). The memories described in the embodiments of this invention are intended to include, but are not limited to, these and any other suitable categories of memory.

[0116] In this embodiment of the invention, the memory 402 is used to store various types of data to support the operation of the electronic terminal 400. Examples of this data include: any executable program for operation on the electronic terminal 400, such as the operating system 4021 and application programs 4022; the operating system 4021 contains various system programs, such as the framework layer, core library layer, driver layer, etc., for implementing various basic services and handling hardware-based tasks. The application program 4022 may contain various applications, such as a media player, browser, etc., for implementing various application services. The methods provided in this embodiment of the invention can be included in the application program 4022.

[0117] The methods disclosed in the above embodiments of the present invention can be applied to processor 401, or implemented by processor 401. Processor 401 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in processor 401 or by instructions in the form of software. The processor 401 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Processor 401 can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. General-purpose processor 401 may be a microprocessor or any conventional processor, etc. The steps of the accessory optimization method provided in the embodiments of the present invention can be directly reflected as being executed by a hardware decoding processor, or being executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, which is located in a memory. The processor reads the information in the memory and combines it with its hardware to complete the steps of the aforementioned method.

[0118] In an exemplary embodiment, the electronic terminal 400 may be used by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), or complex programmable logic devices (CPLDs) to execute the aforementioned method.

[0119] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute... Figures 1 to 2 The method of any of the embodiments shown.

[0120] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing program code, which, when executed on a computer, causes the computer to perform... Figures 1 to 2 The method of any of the embodiments shown.

[0121] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0122] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0123] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0125] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0127] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., high-density digital video discs (DVDs), or semiconductor media (e.g., solid-state disks (SSDs)).

[0128] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0129] In summary, addressing the technical problem of existing technologies relying on full charge and OCV data for SOC calibration, this application provides a battery state of charge calibration method, apparatus, medium, terminal, and program product. It calculates a first full charge calibration compensation value and a second full charge calibration compensation value during each full charge state, which are used to calibrate the state of charge when reaching a virtual point during the next charge. Specifically, under the premise of meeting the calibration preconditions, if the acquired highest voltage data of a single cell reaches the virtual voltage of a preset virtual point, then a state of charge compensation value is calculated based on the virtual state of charge value of the virtual point and the first and second full charge calibration compensation values ​​calculated during the previous full charge. Furthermore, it determines whether the calculated state of charge compensation value is within the allowable calibration range according to preset judgment conditions. If the value is within the allowable calibration range, further calibration is performed according to the preset calibration formula to obtain the calibrated state of charge (SOC) value. If the value is outside the allowable calibration range, an end message is returned. If, under the premise of meeting the preconditions for calibration, the acquired highest voltage data of a single cell does not reach the virtual voltage, but the actual SOC value under the current state reaches the virtual SOC value, calibration is performed according to the preset hold strategy until the highest voltage data of the single cell reaches the virtual voltage. When the virtual voltage is reached, calibration is performed according to the above calibration steps. This application can achieve SOC calibration under long-term uncharged conditions and reduces the dependence on open-circuit voltage data. Even if there is a certain deviation in the open-circuit voltage data at the virtual point, the impact of the open-circuit voltage data on the accuracy of SOC estimation can be reduced, thereby improving the accuracy of SOC calibration. Therefore, this application effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0130] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for calibrating the state of charge of a battery, characterized in that, include: Determine if the first full charge is complete. If the first full charge is not complete, return a prompt message indicating the end of calibration. If the first full charge is completed, obtain the first full charge calibration compensation value and the second full charge calibration compensation value calculated under the first full charge state and proceed to the following calibration steps; Obtain the highest voltage data of a single cell during this charging state; If the preconditions for calibration are met and the highest voltage data of the acquired individual cell reaches the virtual voltage of the preset virtual point, then the state of charge compensation value is calculated based on the virtual state of charge value of the virtual point, the first full charge calibration compensation value and the second full charge calibration compensation value of the first full charge state; if the calculated state of charge compensation value is within the allowable calibration range according to the preset judgment conditions, then further calibration is performed according to the preset calibration formula to obtain the calibrated state of charge value. If the calculated state of charge compensation value is not within the allowable calibration range according to the preset judgment conditions, the end message is returned. If the pre-calibration conditions are met, the highest voltage data of a single cell does not reach the virtual voltage and the actual state of charge value in the current state reaches the virtual state of charge value, then calibration is performed according to the preset holding strategy until the highest voltage data of the single cell reaches the virtual voltage. If the current charging state reaches full charge, the first full charge calibration compensation value and the second full charge calibration compensation value for this full charge state are calculated and updated for use in the virtual point charge state calibration during the next charging.

2. The battery state-of-charge calibration method according to claim 1, characterized in that, The calculation process for the first and second full-charge calibration compensation values ​​for each full-charge state includes: When the battery is charged to the virtual point, obtain the first state of charge value and the first cumulative charging capacity at the current moment; When the battery is fully charged, the second cumulative charging capacity at the time of full charge is obtained, and the second state of charge value is calculated based on the first cumulative charging capacity and the second cumulative charging capacity. The first state of charge deviation value and the second state of charge deviation value are calculated based on the second state of charge value, the first state of charge value, and the virtual state of charge value of the virtual point. The first and second full charge calibration compensation values ​​are calculated, updated, and stored based on the calculated first and second state of charge deviation values.

3. The battery state-of-charge calibration method according to claim 2, characterized in that, The specific process of calculating, updating, and storing the first and second full-charge calibration compensation values ​​based on the calculated first and second state-of-charge deviation values ​​includes: If the absolute value of the first state of charge deviation is less than or equal to the first error, the first full charge calibration compensation value is zero, and the second full charge calibration compensation value is calculated based on the number of times the charge was not fully charged and the second state of charge deviation value. If the absolute value of the calculated second full charge calibration compensation value is less than or equal to the second error, the second full charge calibration compensation value is set to zero. If the absolute value of the first state of charge deviation is between the first error and the third error, then the first full charge calibration compensation value is calculated based on the first state of charge deviation and the first error. If the first state of charge deviation value is between the negative of the third error and the negative of the first error, then the first full charge calibration compensation value is calculated based on the first state of charge deviation value and the first error. If the absolute value of the first state of charge deviation exceeds the third error, then switch to manual calibration mode.

4. The battery state-of-charge calibration method according to claim 1, characterized in that, The calibration process based on the preset holding strategy until the highest voltage data of the single cell reaches the virtual voltage is as follows: obtain the state of charge value at the current moment and the state of charge value at the next moment, and calculate the change value of the state of charge of both; multiply the change value of the state of charge by the holding coefficient to perform holding calibration until the highest voltage data of the single cell reaches the virtual voltage.

5. The battery state-of-charge calibration method according to claim 4, characterized in that, If the difference between the actual state of charge (SNC) and the virtual state of charge (VNC) is less than or equal to the fourth error, the retention factor is the first retention factor; if the difference between the actual SNC and the VNC is between the fourth and fifth errors, the retention factor is the second retention factor; if the difference between the actual SNC and the VNC is greater than the fifth error, the retention factor is the third retention factor.

6. The battery state-of-charge calibration method according to claim 1, characterized in that, The virtual voltage of the virtual point is preset based on the current, the lowest temperature of the single unit, and the number of cycles.

7. A battery state-of-charge calibration device, characterized in that, include: The first full charge determination module is used to determine whether the first full charge is completed. If the first full charge is not completed, a prompt message indicating the end of calibration is returned. If the first full charge is completed, obtain the first full charge calibration compensation value and the second full charge calibration compensation value calculated under the first full charge state and proceed to the following calibration steps; The calibration module is used to obtain the highest voltage data of a single cell during this charging state; If the preconditions for calibration are met and the highest voltage data of the acquired individual cell reaches the virtual voltage of the preset virtual point, then the state of charge compensation value is calculated based on the virtual state of charge value of the virtual point, the first full charge calibration compensation value and the second full charge calibration compensation value of the first full charge state; if the calculated state of charge compensation value is within the allowable calibration range according to the preset judgment conditions, then further calibration is performed according to the preset calibration formula to obtain the calibrated state of charge value. If the calculated state of charge compensation value is not within the allowable calibration range according to the preset judgment conditions, the end information is returned; if the calibration preconditions are met, the highest voltage data of the single cell does not reach the virtual voltage and the actual state of charge value in the current state reaches the virtual state of charge value, then the calibration is performed according to the preset holding strategy until the highest voltage data of the single cell reaches the virtual voltage. The update module is used to calculate and update the first full charge calibration compensation value and the second full charge calibration compensation value when the current charging state reaches the full charge state, so as to be used for virtual point charge state calibration during the next charging.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.

9. A computer program product, characterized in that, The computer program product includes computer program code that, when run on a computer, causes the computer to implement the method as described in any one of claims 1 to 6.

10. An electronic terminal, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method as described in any one of claims 1 to 6.

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