Calibration method and device for SOC (State of Charge) of battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery SOC calibration method and device. The method comprises the steps of obtaining a current charging temperature value, a maximum monomer voltage, a current charging SOC and a charging current value within a current preset SOC threshold step length of battery charging; according to the current charging temperature value, the maximum monomer voltage, the current charging SOC and the charging current value, the calibrated current charging SOC is determined until the maximum monomer voltage or the current charging SOC meets the calibration requirement; acquiring the current discharge temperature value, the minimum monomer voltage, the current discharge SOC and the discharge current value in the current preset SOC threshold step length of battery discharge; and according to the current discharge temperature value, the minimum monomer voltage, the current discharge SOC and the discharge current value, determining the calibrated current discharge SOC until the minimum monomer voltage or the current discharge SOC meets the calibration requirement. According to the invention, the SOC error of the battery can be calibrated in real time.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method and apparatus for calibrating battery state of charge (SOC). Background Technology

[0002] Currently, with the increasing sales of electric vehicles, the battery is crucial for vehicle safety, making battery research and development paramount. Existing technologies use the ampere-hour integration method to estimate the battery's State of Charge (SOC). However, this method is prone to error, which accumulates over time and amplifies. The open-circuit voltage method is used as a compensation algorithm for calibrating battery SOC using the ampere-hour integration method. However, the open-circuit voltage method requires sufficient resting time and can only be used within a specific SOC range, resulting in stringent calibration conditions and limited calibration opportunities. Therefore, a new battery SOC calibration method is urgently needed that improves calibration conditions and increases calibration opportunities. Summary of the Invention

[0003] Therefore, it is necessary to provide a method and apparatus for calibrating battery SOC to address the aforementioned technical problems.

[0004] Firstly, a method for calibrating the state of charge (SOC) of a battery is provided, the method comprising: Within the current preset SOC threshold step of battery charging, obtain the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery; Based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, determine the calibrated current charging SOC until the maximum single-cell voltage or the current charging SOC reaches the calibration requirements. Within the current preset SOC threshold step of the battery discharge, the current discharge temperature value, minimum single cell voltage, current discharge SOC, and discharge current value of the battery are obtained. Based on the current discharge temperature, the minimum single-cell voltage, the current discharge SOC, and the discharge current, the calibrated current discharge SOC is determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0005] As an optional implementation, determining the calibrated current charging SOC based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements, includes: If the charging current value is not within the preset charging current threshold range, the battery current is determined to be abnormal; otherwise, the current charging dynamic voltage curve corresponding to the current charging temperature value is queried from the pre-stored correspondence between charging temperature value and charging dynamic voltage curve; the charging dynamic voltage curve is composed of multiple charging dynamic voltage thresholds of various step sizes, and the charging dynamic voltage threshold corresponds to the battery's calibration point charging SOC. Based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, the calibrated current charging SOC is determined until the maximum single-cell voltage or the current charging SOC meets the calibration requirements.

[0006] As an optional implementation, determining the calibrated current discharge SOC based on the current discharge temperature value, the minimum single-cell voltage, the current discharge SOC, and the discharge current value, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements, includes: The step of determining the calibrated current discharge SOC based on the current discharge temperature value, the minimum single-cell voltage, the current discharge SOC, and the discharge current value, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements, includes: If the discharge current value is not within the preset discharge current threshold range, the battery current is determined to be abnormal; otherwise, the current discharge dynamic voltage curve corresponding to the current discharge temperature value is queried from the pre-stored correspondence between discharge temperature value and discharge dynamic voltage curve. The discharge dynamic voltage curve is composed of multiple step-size discharge dynamic voltage thresholds, and the discharge dynamic voltage threshold corresponds to the battery's calibration point discharge SOC. Based on the minimum single-cell voltage, the current discharge SOC, the calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, the calibrated current discharge SOC is determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0007] As an optional implementation, determining the calibrated current charging SOC based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements, includes: If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is not equal to the maximum preset SOC threshold, then the charging SOC rate of the battery is reduced to the charging SOC rate of the first preset proportional coefficient, and the sum of the current charging SOC and the product of the first preset proportional coefficient and the charging SOC rate is determined as the calibrated current charging SOC, until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold; If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is equal to the maximum preset SOC threshold, then the value of the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold and the current charging SOC is greater than or equal to the maximum preset SOC threshold, then the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the current charging SOC is equal to the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is less than the difference between the calibration point charging SOC and the second preset proportional coefficient, then according to the preset increase cycle, the sum of the current charging SOC and the second preset proportional coefficient is determined as the calibrated current charging SOC, until the current charging SOC equals the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is greater than or equal to the difference between the calibration point charging SOC and the second preset proportional coefficient, and less than the calibration point charging SOC, then the calibration point charging SOC is determined as the calibrated current charging SOC.

[0008] As an optional implementation, determining the calibrated current discharge SOC based on the minimum single-cell voltage, the current discharge SOC, the calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements, includes: If the minimum single-cell voltage is less than the current discharge dynamic voltage threshold and the current discharge SOC is greater than the calibration point discharge SOC, then the current discharge SOC is reduced by a second preset proportional coefficient according to a preset period until the calibrated current discharge SOC is equal to the calibration point discharge SOC. If the minimum single-cell voltage is greater than the current discharge dynamic voltage threshold and the current discharge SOC is less than the calibration point discharge SOC, then the discharge SOC rate is reduced to the discharge SOC rate of the first preset proportional coefficient, and the sum of the current discharge SOC and the product of the first preset proportional coefficient and the discharge SOC rate is determined as the calibrated current discharge SOC, until the minimum single-cell voltage is equal to the current discharge dynamic voltage threshold.

[0009] As an optional implementation, the method further includes: After the battery starts charging, when the current charging SOC reaches the first calibration point charging SOC, the first current dynamic voltage value of the battery is detected according to the preset SOC threshold step size of the battery, and the second current dynamic voltage value of multiple calibration points is detected. Based on the first current dynamic voltage value, the second current dynamic voltage value, and the pre-stored calibration dynamic voltage, determine whether the battery voltage value is normal; If the voltage is normal, then the steps of obtaining the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of battery charging are executed. If the current charging SOC is equal to the maximum preset SOC threshold and the battery is fully charged, then the target preset SOC is determined as the calibrated current charging SOC.

[0010] As an optional implementation, determining whether the battery voltage is normal based on the first current dynamic voltage value, the second current dynamic voltage value, and a pre-stored calibration dynamic voltage includes: The first difference between the first current dynamic voltage value and the first difference between the pre-stored calibrated dynamic voltage, and the second difference between the second current dynamic voltage value and the pre-stored calibrated dynamic voltage, are compared with a preset difference threshold. If both the first difference and the second difference are greater than the preset difference threshold, the battery voltage is determined to be abnormal; otherwise, the voltage is determined to be normal.

[0011] As an optional implementation, the method further includes: During the battery discharge process, if the current charging SOC is equal to the minimum preset SOC threshold and the battery is fully discharged, then 0% is determined as the calibrated current charging SOC.

[0012] Secondly, a battery SOC calibration device is provided, the device comprising: The first acquisition module is used to acquire the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of battery charging. The first calibration module is used to determine the calibrated current charging SOC based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements. The second acquisition module is used to acquire the current discharge temperature value, minimum single cell voltage, current discharge SOC and discharge current value of the battery within the current preset SOC threshold step of the battery discharge. The second calibration module is used to determine the calibrated current discharge SOC based on the current discharge temperature value, the minimum single-cell voltage, the current discharge SOC, and the discharge current value, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0013] As an optional implementation, the first calibration module is specifically used for: If the charging current value is not within the preset charging current threshold range, the battery current is determined to be abnormal; otherwise, the current charging dynamic voltage curve corresponding to the current charging temperature value is queried from the pre-stored correspondence between charging temperature value and charging dynamic voltage curve; the charging dynamic voltage curve is composed of multiple charging dynamic voltage thresholds of various step sizes, and the charging dynamic voltage threshold corresponds to the battery's calibration point charging SOC. Based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, the calibrated current charging SOC is determined until the maximum single-cell voltage or the current charging SOC meets the calibration requirements.

[0014] As an optional implementation, the second calibration module is specifically used for: If the discharge current value is not within the preset discharge current threshold range, the battery current is determined to be abnormal; otherwise, the current discharge dynamic voltage curve corresponding to the current discharge temperature value is queried from the pre-stored correspondence between discharge temperature value and discharge dynamic voltage curve. The discharge dynamic voltage curve is composed of multiple step-size discharge dynamic voltage thresholds, and the discharge dynamic voltage threshold corresponds to the battery's calibration point discharge SOC. Based on the minimum single-cell voltage, the current discharge SOC, the calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, the calibrated current discharge SOC is determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0015] As an optional implementation, the first calibration module is specifically used for: If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is not equal to the maximum preset SOC threshold, then the charging SOC rate of the battery is reduced to the charging SOC rate of the first preset proportional coefficient, and the sum of the current charging SOC and the product of the first preset proportional coefficient and the charging SOC rate is determined as the calibrated current charging SOC, until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold; If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is equal to the maximum preset SOC threshold, then the value of the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold and the current charging SOC is greater than or equal to the maximum preset SOC threshold, then the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the current charging SOC is equal to the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is less than the difference between the calibration point charging SOC and the second preset proportional coefficient, then according to the preset increase cycle, the sum of the current charging SOC and the second preset proportional coefficient is determined as the calibrated current charging SOC, until the current charging SOC equals the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is greater than or equal to the difference between the calibration point charging SOC and the second preset proportional coefficient, and less than the calibration point charging SOC, then the calibration point charging SOC is determined as the calibrated current charging SOC.

[0016] As an optional implementation, the second calibration module is specifically used for: If the minimum single-cell voltage is less than the current discharge dynamic voltage threshold and the current discharge SOC is greater than the calibration point discharge SOC, then the current discharge SOC is reduced by a second preset proportional coefficient according to a preset period until the calibrated current discharge SOC is equal to the calibration point discharge SOC. If the minimum single-cell voltage is greater than the current discharge dynamic voltage threshold and the current discharge SOC is less than the calibration point discharge SOC, then the discharge SOC rate is reduced to the discharge SOC rate of the first preset proportional coefficient, and the sum of the current discharge SOC and the product of the first preset proportional coefficient and the discharge SOC rate is determined as the calibrated current discharge SOC, until the minimum single-cell voltage is equal to the current discharge dynamic voltage threshold.

[0017] As an optional implementation, the device further includes: The detection module is used to detect the first current dynamic voltage value of the battery according to the preset SOC threshold step size of the battery after the battery starts charging and when the current charging SOC reaches the first calibration point charging SOC, and to detect the second current dynamic voltage value of multiple calibration points. The determination module is used to determine whether the voltage value of the battery is normal based on the first current dynamic voltage value, the second current dynamic voltage value and the pre-stored calibration dynamic voltage. The third acquisition module is used to execute the steps of acquiring the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of the battery charging if the voltage is normal. The determination module is used to determine the target preset SOC as the calibrated current charging SOC if the current charging SOC is equal to the maximum preset SOC threshold and the battery is fully charged.

[0018] As an optional implementation, the determination module is specifically used for: The first difference between the first current dynamic voltage value and the first difference between the pre-stored calibrated dynamic voltage, and the second difference between the second current dynamic voltage value and the pre-stored calibrated dynamic voltage, are compared with a preset difference threshold. If both the first difference and the second difference are greater than the preset difference threshold, the battery voltage is determined to be abnormal; otherwise, the voltage is determined to be normal.

[0019] As an optional implementation, the device further includes: During the battery discharge process, if the current charging SOC is equal to the minimum preset SOC threshold and the battery is fully discharged, then 0% is determined as the calibrated current charging SOC.

[0020] Thirdly, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program executable on the processor, and the processor executes the computer program to perform the steps of the method described in the first aspect.

[0021] Fourthly, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0022] This application provides a method for calibrating battery SOC. The technical solution provided by the embodiments of this application brings at least the following beneficial effects: During battery charging or discharging, the actual SOC can be brought closer to the calibration point SOC by accelerating or limiting the SOC based on the dynamic voltage at the calibration point in real time, thereby reducing intermediate errors in real time and avoiding the problem of falsely high or low SOC caused by the cumulative error of the ampere-hour integration method. Timely calibration of SOC through the dynamic voltage calibration point before full charging reduces errors and improves the situation where users end charging before it is fully charged, causing the battery management system to fail to trigger full-charge calibration to eliminate errors. This greatly reduces calibration conditions and increases calibration opportunities.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A flowchart illustrating a battery SOC calibration method provided in this application embodiment; Figure 2 A flowchart illustrating an example of a battery charging SOC calibration method provided in this application embodiment; Figure 3 A schematic diagram of a battery SOC calibration device provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] The following will describe in detail a battery SOC calibration method provided in this application, with reference to specific implementation methods. Figure 1A flowchart illustrating a battery SOC calibration method provided in this application embodiment is shown below. Figure 1 As shown, the specific steps are as follows: Step 101: Within the current preset SOC threshold step size for battery charging, obtain the current charging temperature value, maximum single cell voltage, current charging SOC, and charging current value of the battery.

[0028] In practice, existing technologies use the open-circuit voltage method as a compensation algorithm for calibrating battery SOC using the ampere-hour integration method. However, the open-circuit voltage method requires sufficient rest time, resulting in stringent calibration conditions and limited calibration opportunities. To improve calibration conditions and increase calibration opportunities, this application employs a dynamic voltage calibration method to calibrate the battery's SOC, dividing the calibration into charging SOC during charging and discharging SOC during discharging. First, the charging SOC during charging is calibrated. Since charging temperature significantly affects battery capacity, multiple dynamic charging voltage curves corresponding to different charging temperatures can be calibrated. Dynamic voltage data for other temperatures are obtained through interpolation of existing dynamic voltage data at specific temperature points. Therefore, it is necessary to first obtain the current charging temperature value and the calibration point charging SOC corresponding to the charging dynamic voltage threshold. During battery charging, an error exists between the charging SOC and the calibration point charging SOC. Consequently, errors also exist between the battery's corresponding charging dynamic voltage and the maximum single-cell voltage of the battery pack composed of multiple small cells connected in series. Therefore, it is also necessary to obtain the maximum single-cell voltage and the current charging SOC. The calibration point charging SOC can be obtained based on the dynamic charging voltage curve corresponding to the charging temperature value. It is also necessary to obtain the charging current value to determine whether the battery current is in a normal state; calibration can only be performed if it is in a normal state. Therefore, within the current preset SOC threshold step of battery charging, the current charging temperature value, maximum single-cell voltage, current charging SOC, and charging current value of the battery can be obtained first.

[0029] Step 102: Determine the calibrated current charging SOC based on the current charging temperature, maximum single-cell voltage, current charging SOC, and charging current, until the maximum single-cell voltage or current charging SOC meets the calibration requirements.

[0030] In practice, the current charging SOC of the battery can be calibrated based on the current charging temperature, maximum single-cell voltage, current charging SOC, and charging current to determine the calibrated current charging SOC until the maximum single-cell voltage or current charging SOC meets the calibration requirements.

[0031] Specifically, the process of executing step 102 is as follows: Step 1: If the charging current value is not within the preset charging current threshold range, the battery current is determined to be abnormal. Otherwise, the current charging dynamic voltage curve corresponding to the current charging temperature value is queried from the pre-stored correspondence between charging temperature value and charging dynamic voltage curve. The charging dynamic voltage curve is composed of multiple charging dynamic voltage thresholds of different step sizes, and the charging dynamic voltage threshold corresponds to the battery's calibration point charging SOC.

[0032] In implementation, the battery current is assessed using the acquired charging current value to determine if it is within a normal range. Calibration can only be performed when the battery is in a normal range; attempting calibration when the battery is in an abnormal range will result in incorrect calibration. The charging current is checked against a preset charging current threshold. If the charging current is outside this threshold, the battery current is considered abnormal; if it is within the threshold, the current is considered normal, and calibration can proceed. Since charging temperature significantly impacts battery capacity, multiple dynamic charging voltage curves corresponding to different charging temperatures can be calibrated. Technicians pre-store the correspondence between charging temperature values ​​and dynamic charging voltage curves. The current dynamic charging voltage curve corresponding to the current charging temperature value is then retrieved from this pre-stored database. Each dynamic charging voltage curve consists of multiple dynamic charging voltage thresholds of varying steps, with each threshold representing the battery's state of charge (SOC) at the calibration point.

[0033] Step 2: Determine the calibrated current charging SOC based on the maximum single-cell voltage, current charging SOC, calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, until the maximum single-cell voltage or current charging SOC meets the calibration requirements.

[0034] In practice, the current charging SOC of the battery can be calibrated based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, and the calibrated current charging SOC can be determined until the maximum single-cell voltage or the current charging SOC meets the calibration requirements.

[0035] Specifically, the process for executing step two is as follows: Step A: If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is not equal to the maximum preset SOC threshold, then the battery charging SOC rate is reduced to the charging SOC rate of the first preset proportional coefficient, and the sum of the current charging SOC and the product of the first preset proportional coefficient and the charging SOC rate is determined as the calibrated current charging SOC, until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold.

[0036] In implementation, the maximum single-cell voltage is compared with the current dynamic charging voltage threshold, and the current charging SOC is compared with the calibration point charging SOC. If the maximum single-cell voltage is less than the current dynamic charging voltage threshold, and the current charging SOC is greater than the calibration point charging SOC, it indicates that the current battery charging SOC is artificially high. It is also necessary to compare the calibration point charging SOC with the maximum preset SOC threshold. If the calibration point charging SOC is not equal to the maximum preset SOC threshold, it indicates that the current charging SOC is not fully charged. The maximum preset SOC threshold can be 99%. Therefore, calibration can limit the rate of increase in charging SOC, reducing the battery's charging SOC rate to a first preset proportional coefficient, which can be 1%. This significantly reduces the rate of increase in the current charging SOC. Then, the sum of the current charging SOC and the product of the first preset proportional coefficient and the charging SOC rate is determined as the calibrated current charging SOC, until the maximum single-cell voltage equals the current dynamic charging voltage threshold. When the maximum single-cell voltage catches up with the current dynamic voltage threshold, the rate limiting is removed to restore normal charging logic.

[0037] Step B: If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is equal to the maximum preset SOC threshold, then the charging SOC rate is set to 0, and the current charging SOC remains unchanged until the maximum single-cell voltage equals the current charging dynamic voltage threshold.

[0038] In practice, if the maximum single-cell voltage is less than the current dynamic charging voltage threshold, and the current charging SOC is greater than the calibration point charging SOC, it indicates that the current battery charging SOC is artificially high. It is also necessary to compare the calibration point charging SOC with the maximum preset SOC threshold. If the calibration point charging SOC equals the maximum preset SOC threshold, it means the current charging SOC has reached 100%, the battery is fully charged, and the charging SOC rate is set to 0. The current charging SOC remains unchanged until the maximum single-cell voltage equals the current dynamic charging voltage threshold.

[0039] Step C: If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold and the current charging SOC is greater than or equal to the maximum preset SOC threshold, then the charging SOC rate is set to 0, and the current charging SOC remains unchanged until the current charging SOC equals the calibration point charging SOC.

[0040] In practice, the maximum single-cell voltage is compared with the current dynamic charging voltage threshold, and the current charging SOC is compared with the maximum preset SOC threshold, which can be 99%. If the maximum single-cell voltage is greater than the current dynamic charging voltage threshold, and the current charging SOC is greater than or equal to the maximum preset SOC threshold, it means that the current charging SOC has reached 100%, the battery is fully charged, the charging SOC rate is set to 0, and the current charging SOC remains unchanged until the current charging SOC equals the calibration point charging SOC.

[0041] Step D: If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is less than the difference between the calibration point charging SOC and the second preset proportional coefficient, then according to the preset increase cycle, the sum of the current charging SOC and the second preset proportional coefficient is determined as the calibrated current charging SOC, until the current charging SOC equals the calibration point charging SOC.

[0042] In implementation, the maximum single-cell voltage is compared with the current dynamic charging voltage threshold, and the current charging SOC is compared with the maximum preset SOC threshold, which can be 99%. If the maximum single-cell voltage is greater than the current dynamic charging voltage threshold, but the current charging SOC is less than the maximum preset SOC threshold, it indicates that the current charging SOC has not yet reached 100%. The current charging SOC also needs to be compared with the difference between the calibration point charging SOC and the second preset proportional coefficient. If the current charging SOC is less than the difference, it indicates that the current charging SOC is artificially low and needs to be increased. Following a preset increase period, the sum of the current charging SOC and the second preset proportional coefficient can be determined as the calibrated current charging SOC, until the current charging SOC equals the calibration point charging SOC. The preset increase period can be M seconds, and the second preset proportional coefficient can be 2%.

[0043] Step E: If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is greater than or equal to the difference between the calibration point charging SOC and the second preset proportional coefficient, and less than the calibration point charging SOC, then the calibration point charging SOC is determined as the calibrated current charging SOC.

[0044] In implementation, the maximum single-cell voltage is compared with the current dynamic charging voltage threshold, and the current charging SOC is compared with the maximum preset SOC threshold, which can be 99%. If the maximum single-cell voltage is greater than the current dynamic charging voltage threshold, and the current charging SOC is less than the maximum preset SOC threshold, it indicates that the current charging SOC has not yet reached 100%. It is also necessary to compare the current charging SOC with the difference between the calibration point charging SOC and the second preset proportional coefficient. If the current charging SOC is greater than or equal to the difference between the calibration point charging SOC and the second preset proportional coefficient, and less than the calibration point charging SOC, it indicates that the difference between the current charging SOC and the calibration point charging SOC is small. In this case, the calibration point charging SOC can be directly determined as the calibrated current charging SOC, directly matching the calibration point charging SOC.

[0045] Step 103: Within the current preset SOC threshold step size for battery discharge, obtain the current discharge temperature value, minimum single cell voltage, current discharge SOC, and discharge current value of the battery.

[0046] In implementation, the battery's discharge SOC is calibrated during discharge. Since discharge temperature significantly affects battery capacity, multiple dynamic discharge voltage curves corresponding to different discharge temperatures can be calibrated. Dynamic voltage data for other temperatures are obtained through interpolation of existing dynamic voltage data at specific temperature points. Therefore, the battery's current discharge temperature and the calibration point discharge SOC corresponding to the discharge dynamic voltage threshold can be obtained first. During battery discharge, the discharge SOC and the calibration point discharge SOC may differ, resulting in a discrepancy between the battery's corresponding discharge dynamic voltage and the minimum single-cell voltage of the battery pack composed of multiple small cells connected in series. Therefore, the minimum single-cell voltage and the current discharge SOC also need to be obtained. The calibration point discharge SOC can be obtained based on the discharge dynamic voltage from the dynamic discharge voltage curve corresponding to the discharge temperature. The discharge current value also needs to be obtained to determine if the battery current is within a normal range; calibration can only be performed if it is within this range. Therefore, within the current preset SOC threshold step size for battery discharge, the battery's current discharge temperature, minimum single-cell voltage, current discharge SOC, and discharge current value are obtained.

[0047] Step 104: Determine the calibrated current discharge SOC based on the current discharge temperature, minimum single-cell voltage, current discharge SOC, and discharge current, until the minimum single-cell voltage or current discharge SOC meets the calibration requirements.

[0048] In practice, the current discharge SOC of the battery can be calibrated based on the current discharge temperature, minimum single-cell voltage, current discharge SOC, and discharge current value to determine the calibrated current discharge SOC until the minimum single-cell voltage or current discharge SOC meets the calibration requirements.

[0049] Specifically, the process of executing step 104 is as follows: Step 3: If the discharge current value is not within the preset discharge current threshold range, the battery current is determined to be abnormal. Otherwise, the current discharge dynamic voltage curve corresponding to the current discharge temperature value is queried from the pre-stored correspondence between discharge temperature value and discharge dynamic voltage curve. The discharge dynamic voltage curve is composed of multiple discharge dynamic voltage thresholds of different step sizes. The discharge dynamic voltage threshold corresponds to the battery's calibration point discharge SOC.

[0050] In practice, the battery current is determined by the obtained discharge current value to ensure it is within a normal range. Calibration can only be performed when the battery is in a normal range; calibration under abnormal conditions will lead to incorrect calibration. The system checks if the discharge current is within a preset discharge current threshold range. If the discharge current is outside this range, the battery current is considered abnormal; if it is within the threshold range, the current is considered normal and calibration can proceed. Since discharge temperature significantly affects battery capacity, multiple dynamic discharge voltage curves corresponding to different discharge temperatures can be calibrated. Technicians pre-store the correspondence between discharge temperature values ​​and dynamic discharge voltage curves. The system then queries the current dynamic discharge voltage curve corresponding to the current discharge temperature value from this pre-stored database. Each dynamic discharge voltage curve consists of multiple step-size dynamic discharge voltage thresholds, and each threshold corresponds to the battery's calibration point discharge state of charge (SOC).

[0051] Step 4: Determine the calibrated current discharge SOC based on the minimum single-cell voltage, current discharge SOC, calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, until the minimum single-cell voltage or current discharge SOC meets the calibration requirements.

[0052] In practice, the current discharge SOC of the battery can be calibrated based on the minimum single-cell voltage, the current discharge SOC, the discharge SOC at the calibration point, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, and the calibrated current discharge SOC can be determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0053] Specifically, the process for step four is as follows: Step a: If the minimum single-cell voltage is less than the current discharge dynamic voltage threshold and the current discharge SOC is greater than the calibration point discharge SOC, then the current discharge SOC is reduced by a second preset proportional coefficient according to a preset period until the calibrated current discharge SOC is equal to the calibration point discharge SOC.

[0054] In implementation, the minimum single-cell voltage is compared with the current dynamic discharge voltage threshold, and the current discharge SOC is compared with the calibration point discharge SOC. If the minimum single-cell voltage is less than the current dynamic discharge voltage threshold, and the current discharge SOC is greater than the calibration point discharge SOC, it indicates that the current battery discharge SOC is artificially high. The current discharge SOC can be reduced by a second preset proportional coefficient at a preset period until the calibrated current discharge SOC equals the calibration point discharge SOC. The second preset proportional coefficient can be 2%, and the preset period can be M seconds. For example, the current discharge SOC can be reduced by 2% every M seconds to catch up to the calibration point discharge SOC, after which normal discharge logic is restored.

[0055] Step b: If the minimum single-cell voltage is greater than the current discharge dynamic voltage threshold and the current discharge SOC is less than the calibration point discharge SOC, then the discharge SOC rate is reduced to the discharge SOC rate of the first preset proportional coefficient, and the sum of the current discharge SOC and the product of the first preset proportional coefficient and the discharge SOC rate is determined as the calibrated current discharge SOC, until the minimum single-cell voltage is equal to the current discharge dynamic voltage threshold.

[0056] In implementation, the minimum single-cell voltage is compared with the current discharge dynamic voltage threshold, and the current discharge SOC is compared with the calibration point discharge SOC. If the minimum single-cell voltage is greater than the current discharge dynamic voltage threshold, and the current discharge SOC is less than the calibration point discharge SOC, it indicates that the current discharge SOC is falsely low. The current discharge SOC after calibration can be determined by the sum of the current discharge SOC and the product of a first preset proportional coefficient and the discharge SOC rate, until the minimum single-cell voltage equals the current discharge dynamic voltage threshold. The first preset proportional coefficient can be 1%. For example, the current discharge SOC can be limited to 1% of its original value. Once the minimum single-cell voltage catches up to the current discharge dynamic voltage threshold corresponding to the current discharge SOC, normal logic is restored.

[0057] Furthermore, to avoid miscalibration when calibrating a battery with an abnormal dynamic voltage, it is necessary to first determine whether the battery voltage is in an abnormal state. The specific process is as follows: Step 1) After the battery starts charging, when the current charging SOC reaches the first calibration point charging SOC, the first current dynamic voltage value of the battery is detected according to the preset SOC threshold step size of the battery, and the second current dynamic voltage value of multiple calibration points is detected.

[0058] In implementation, after the battery begins charging, when the current state of charge (SOC) reaches the first calibration point SOC, the battery's first current dynamic voltage value is detected according to a preset SOC threshold step size, and the second current dynamic voltage value at multiple calibration points is also detected. These multiple calibration points can be A1, A2, A3, and A4, with SOC calibration points set in an incremental gradient; A4 can be 99%. Because the battery charge / discharge curve exhibits plateau and non-plateau periods, calibration points need to be selected during non-plateau periods. The preset SOC threshold step size can be 0.5%. For example, when the SOC reaches calibration point A1, the battery's first current dynamic voltage value is recorded starting with a ΔSOC step size of 0.5%, along with the second current dynamic voltage value at the detection point. This approach, combined with the fact that the dynamic voltage does not require sufficient resting time and the setting of multiple calibration points, significantly increases calibration opportunities.

[0059] Step 2) Determine whether the battery voltage is normal based on the first current dynamic voltage value, the second current dynamic voltage value, and the pre-stored calibration dynamic voltage.

[0060] During implementation, after obtaining the first and second current dynamic voltage values, it is necessary to determine whether these values ​​are within the normal range. This can be achieved by using pre-stored calibrated dynamic voltage values ​​to determine if the battery voltage is normal.

[0061] Specifically, in step 2): the first difference between the first current dynamic voltage value and the first difference between the pre-stored calibrated dynamic voltage, the second difference between the second current dynamic voltage value and the second difference between the pre-stored calibrated dynamic voltage, and the preset difference threshold are compared. If both the first difference and the second difference are greater than the preset difference threshold, the battery voltage is determined to be abnormal; otherwise, the voltage is determined to be normal.

[0062] In practice, the first difference between the current dynamic voltage value and the pre-stored calibration dynamic voltage, and the second difference between the current dynamic voltage value and the pre-stored calibration dynamic voltage, can be compared with a preset difference threshold. If both the first and second differences are greater than the preset difference threshold, the dynamic voltage is considered abnormal and calibration cannot be performed, thus indicating an abnormal battery voltage. If both the first and second differences are less than the preset difference threshold, the dynamic voltage is considered normal, SOC calibration can be performed, and the voltage is determined to be normal.

[0063] Step 3) If the voltage is normal, then execute the steps of obtaining the current charging temperature, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of battery charging.

[0064] During implementation, if the battery voltage is normal, it means that the calibration step can be performed. Then, within the current preset SOC threshold step size of battery charging, the steps of obtaining the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery are executed.

[0065] Step 4) If the current charging SOC is equal to the maximum preset SOC threshold and the battery is fully charged, then the target preset SOC is determined as the calibrated current charging SOC.

[0066] In practice, during battery charging, the current charging SOC is compared with the maximum preset SOC threshold. If the current charging SOC equals the maximum preset SOC threshold and the battery is fully charged, the target preset SOC is determined as the calibrated current charging SOC. In this way, the current charging SOC changes from 99% to 100% when fully charged, avoiding the possibility of a jump from 90% to 100% when the SOC is artificially low.

[0067] Furthermore, after the battery begins discharging, when the current discharge SOC reaches the first calibration point discharge SOC, the third current dynamic voltage value of the battery is detected according to the battery's preset SOC threshold step size, and the fourth current dynamic voltage value of multiple calibration points is also detected. These multiple calibration points can be B1, B2, B3, and B4, where B4 can be 1%, and the multiple calibration points are arranged in a decreasing gradient. Based on the third current dynamic voltage value, the fourth current dynamic voltage value, and the pre-stored calibration dynamic voltage, it is determined whether the battery voltage value is normal. If the voltage is normal, the steps of obtaining the battery's current discharge temperature value, minimum single-cell voltage, current discharge SOC, and discharge current value within the current preset SOC threshold step size are executed.

[0068] Furthermore, during the battery discharge process, if the current charging SOC is equal to the minimum preset SOC threshold and the battery is fully discharged, then 0% is determined as the calibrated current charging SOC. In this way, when fully discharged, the current discharge SOC changes from 1% to 0%, which can avoid the possibility of the SOC jumping from 10% to 0% when it is artificially high.

[0069] In practice, during the battery discharge process, the current charging SOC is compared with the minimum preset SOC threshold. If the current charging SOC is equal to the minimum preset SOC threshold and the battery is fully discharged, then 0% is determined as the calibrated current charging SOC.

[0070] This application provides a method for calibrating battery SOC. Based on the dynamic voltage at a calibration point, it accelerates or limits the SOC to bring the actual SOC closer to the calibration point, reducing intermediate errors and improving the problem of artificially high or low SOC caused by accumulated errors in the ampere-hour integration method. Before full charging and discharging, the SOC is calibrated to 99% or 1% using dynamic voltage calibration points at 99% or 1%, avoiding jumps during full charging or discharging due to excessive errors. Timely calibration of the SOC using dynamic voltage calibration points before full charging reduces errors, improving situations where users stop charging before full charge, preventing the BMS system from triggering full-charge calibration to eliminate errors. Setting multiple calibration points, combined with the characteristic that dynamic voltage does not require sufficient rest time, increases SOC calibration opportunities and alleviates the relatively stringent OCV calibration conditions. Anomaly detection of dynamic voltage is added to avoid miscalibration caused by abnormal dynamic voltage.

[0071] Figure 2 A flowchart illustrating an example of a battery charging SOC calibration method provided in this application embodiment. Figure 2 As shown, after calibration begins, the maximum single-cell voltage Vmax, charging current, and current charging temperature are collected. The current charging temperature and the current charging dynamic voltage threshold Vthr1 corresponding to the calibration point SOC are then obtained. If Vmax < Vthr1, timer 1 is cleared and timing begins. After timer 1 ≥ N seconds, the current comparison result is considered stable. If the current charging SOC is greater than the calibration point SOC, it is necessary to determine if the calibration point is equal to 99%. If the current charging SOC equals the calibration point SOC, the calibrated current charging SOC is: SOC = SOC + ΔSOC × 0%. If the current charging SOC is not equal to the calibration point SOC, the calibrated current charging SOC is: SOC = SOC + ΔSOC × 1%. If Vmax ≥ Vthr1, then clear timer 2 and start timing. After timer 2 ≥ M seconds, the current comparison result is considered stable. Determine if the current charging SOC is greater than or equal to 99%. If yes, the calibrated current charging SOC is: SOC = SOC + ΔSOC × 0%. If the current charging SOC is less than 99%, it is also necessary to determine if the current charging SOC < calibration point SOC - 2%. If SOC < calibration point SOC - 2%, the calibrated current charging SOC is: SOC = SOC + 2%. If SOC ≥ calibration point SOC - 2% and SOC < calibration point SOC, the calibrated current charging SOC is: SOC = calibration point SOC.

[0072] It should be understood that, although Figures 1 to 2The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figures 1 to 2 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0073] It is understood that the same / similar parts between the various embodiments of the methods described above in this specification can be referred to each other. Each embodiment focuses on the differences from other embodiments, and relevant parts can be referred to the description of other method embodiments.

[0074] This application also provides a battery SOC calibration device, such as... Figure 3 As shown, the device includes: The first acquisition module 301 is used to acquire the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of battery charging. The first calibration module 302 is used to determine the calibrated current charging SOC based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements. The second acquisition module 303 is used to acquire the current discharge temperature value, minimum single cell voltage, current discharge SOC and discharge current value of the battery within the current preset SOC threshold step of the battery discharge. The second calibration module 304 is used to determine the calibrated current discharge SOC based on the current discharge temperature value, the minimum single-cell voltage, the current discharge SOC, and the discharge current value, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0075] As an optional implementation, the first calibration module 302 is specifically used for: If the charging current value is not within the preset charging current threshold range, the battery current is determined to be abnormal; otherwise, the current charging dynamic voltage curve corresponding to the current charging temperature value is queried from the pre-stored correspondence between charging temperature value and charging dynamic voltage curve; the charging dynamic voltage curve is composed of multiple charging dynamic voltage thresholds of various step sizes, and the charging dynamic voltage threshold corresponds to the battery's calibration point charging SOC. Based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, the calibrated current charging SOC is determined until the maximum single-cell voltage or the current charging SOC meets the calibration requirements.

[0076] As an optional implementation, the second calibration module 304 is specifically used for: If the discharge current value is not within the preset discharge current threshold range, the battery current is determined to be abnormal; otherwise, the current discharge dynamic voltage curve corresponding to the current discharge temperature value is queried from the pre-stored correspondence between discharge temperature value and discharge dynamic voltage curve. The discharge dynamic voltage curve is composed of multiple step-size discharge dynamic voltage thresholds, and the discharge dynamic voltage threshold corresponds to the battery's calibration point discharge SOC. Based on the minimum single-cell voltage, the current discharge SOC, the calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, the calibrated current discharge SOC is determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

[0077] As an optional implementation, the first calibration module 302 is specifically used for: If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is not equal to the maximum preset SOC threshold, then the charging SOC rate of the battery is reduced to the charging SOC rate of the first preset proportional coefficient, and the sum of the current charging SOC and the product of the first preset proportional coefficient and the charging SOC rate is determined as the calibrated current charging SOC, until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold; If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is equal to the maximum preset SOC threshold, then the value of the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold and the current charging SOC is greater than or equal to the maximum preset SOC threshold, then the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the current charging SOC is equal to the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is less than the difference between the calibration point charging SOC and the second preset proportional coefficient, then according to the preset increase cycle, the sum of the current charging SOC and the second preset proportional coefficient is determined as the calibrated current charging SOC, until the current charging SOC equals the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is greater than or equal to the difference between the calibration point charging SOC and the second preset proportional coefficient, and less than the calibration point charging SOC, then the calibration point charging SOC is determined as the calibrated current charging SOC.

[0078] As an optional implementation, the second calibration module 304 is specifically used for: If the minimum single-cell voltage is less than the current discharge dynamic voltage threshold and the current discharge SOC is greater than the calibration point discharge SOC, then the current discharge SOC is reduced by a second preset proportional coefficient according to a preset period until the calibrated current discharge SOC is equal to the calibration point discharge SOC. If the minimum single-cell voltage is greater than the current discharge dynamic voltage threshold and the current discharge SOC is less than the calibration point discharge SOC, then the discharge SOC rate is reduced to the discharge SOC rate of the first preset proportional coefficient, and the sum of the current discharge SOC and the product of the first preset proportional coefficient and the discharge SOC rate is determined as the calibrated current discharge SOC, until the minimum single-cell voltage is equal to the current discharge dynamic voltage threshold.

[0079] As an optional implementation, the device further includes: The detection module is used to detect the first current dynamic voltage value of the battery according to the preset SOC threshold step size of the battery after the battery starts charging and when the current charging SOC reaches the first calibration point charging SOC, and to detect the second current dynamic voltage value of multiple calibration points. The determination module is used to determine whether the voltage value of the battery is normal based on the first current dynamic voltage value, the second current dynamic voltage value and the pre-stored calibration dynamic voltage. The third acquisition module is used to execute the steps of acquiring the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of the battery charging if the voltage is normal. The determination module is used to determine the target preset SOC as the calibrated current charging SOC if the current charging SOC is equal to the maximum preset SOC threshold and the battery is fully charged.

[0080] As an optional implementation, the determination module is specifically used for: The first difference between the first current dynamic voltage value and the first difference between the pre-stored calibrated dynamic voltage, and the second difference between the second current dynamic voltage value and the pre-stored calibrated dynamic voltage, are compared with a preset difference threshold. If both the first difference and the second difference are greater than the preset difference threshold, the battery voltage is determined to be abnormal; otherwise, the voltage is determined to be normal.

[0081] As an optional implementation, the device further includes: During the battery discharge process, if the current charging SOC is equal to the minimum preset SOC threshold and the battery is fully discharged, then 0% is determined as the calibrated current charging SOC.

[0082] This application provides a battery SOC calibration device. Based on the dynamic voltage at a calibration point, it accelerates or limits the SOC to bring the actual SOC closer to the calibration point, reducing intermediate errors and improving the problem of artificially high or low SOC caused by accumulated errors in the ampere-hour integration method. Before full charging and discharging, the SOC is calibrated to 99% or 1% using dynamic voltage calibration points at 99% or 1%, avoiding jumps during full charging or discharging due to excessive errors. Timely calibration of the SOC using dynamic voltage calibration points before full charging reduces errors, improving situations where users stop charging before full charge, preventing the BMS system from triggering full charge calibration to eliminate errors. Multiple calibration points are set, and considering the characteristic that dynamic voltage does not require sufficient rest time, increasing SOC calibration opportunities and improving the relatively stringent OCV calibration conditions. Anomaly detection of dynamic voltage is added to avoid miscalibration caused by abnormal dynamic voltage.

[0083] Specific limitations regarding the calibration device for battery SOC can be found in the limitations of the battery SOC calibration method described above, and will not be repeated here. Each module in the aforementioned battery SOC calibration device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0084] In one embodiment, a computer device is provided, such as Figure 4As shown, it includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the above-described battery SOC calibration method steps.

[0085] In one embodiment, a computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the above-described battery SOC calibration method.

[0086] Those skilled in the art will understand that all or part of the processes in the methods of 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, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0087] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0088] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope 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 protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for calibrating the state of charge (SOC) of a battery, characterized in that, The method includes: Within the current preset SOC threshold step of battery charging, obtain the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery; Based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, determine the calibrated current charging SOC until the maximum single-cell voltage or the current charging SOC reaches the calibration requirements. Within the current preset SOC threshold step of the battery discharge, the current discharge temperature value, minimum single cell voltage, current discharge SOC, and discharge current value of the battery are obtained. Based on the current discharge temperature, the minimum single-cell voltage, the current discharge SOC, and the discharge current, the calibrated current discharge SOC is determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

2. The method according to claim 1, characterized in that, The step of determining the calibrated current charging SOC based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements, includes: If the charging current value is not within the preset charging current threshold range, the battery current is determined to be abnormal; otherwise, the current charging dynamic voltage curve corresponding to the current charging temperature value is queried from the pre-stored correspondence between charging temperature value and charging dynamic voltage curve; the charging dynamic voltage curve is composed of multiple charging dynamic voltage thresholds of various step sizes, and the charging dynamic voltage threshold corresponds to the battery's calibration point charging SOC. Based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, the calibrated current charging SOC is determined until the maximum single-cell voltage or the current charging SOC meets the calibration requirements.

3. The method according to claim 1, characterized in that, The step of determining the calibrated current discharge SOC based on the current discharge temperature value, the minimum single-cell voltage, the current discharge SOC, and the discharge current value, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements, includes: If the discharge current value is not within the preset discharge current threshold range, the battery current is determined to be abnormal; otherwise, the current discharge dynamic voltage curve corresponding to the current discharge temperature value is queried from the pre-stored correspondence between discharge temperature value and discharge dynamic voltage curve. The discharge dynamic voltage curve is composed of multiple step-size discharge dynamic voltage thresholds, and the discharge dynamic voltage threshold corresponds to the battery's calibration point discharge SOC. Based on the minimum single-cell voltage, the current discharge SOC, the calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, the calibrated current discharge SOC is determined until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

4. The method according to claim 2, characterized in that, The step of determining the calibrated current charging SOC based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements, includes: If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is not equal to the maximum preset SOC threshold, then the charging SOC rate of the battery is reduced to the charging SOC rate of the first preset proportional coefficient, and the sum of the current charging SOC and the product of the first preset proportional coefficient and the charging SOC rate is determined as the calibrated current charging SOC, until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold; If the maximum single-cell voltage is less than the current charging dynamic voltage threshold, the current charging SOC is greater than the calibration point charging SOC, and the calibration point charging SOC is equal to the maximum preset SOC threshold, then the value of the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the maximum single-cell voltage is equal to the current charging dynamic voltage threshold. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold and the current charging SOC is greater than or equal to the maximum preset SOC threshold, then the charging SOC rate is determined to be 0, and the current charging SOC remains unchanged until the current charging SOC is equal to the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is less than the difference between the calibration point charging SOC and the second preset proportional coefficient, then according to the preset increase cycle, the sum of the current charging SOC and the second preset proportional coefficient is determined as the calibrated current charging SOC, until the current charging SOC equals the calibration point charging SOC. If the maximum single-cell voltage is greater than the current charging dynamic voltage threshold, the current charging SOC is less than the maximum preset SOC threshold, and the current charging SOC is greater than or equal to the difference between the calibration point charging SOC and the second preset proportional coefficient, and less than the calibration point charging SOC, then the calibration point charging SOC is determined as the calibrated current charging SOC.

5. The method according to claim 3, characterized in that, The step of determining the calibrated current discharge SOC based on the minimum single-cell voltage, the current discharge SOC, the calibration point discharge SOC, and the current discharge dynamic voltage threshold in the current discharge dynamic voltage curve, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements, includes: If the minimum single-cell voltage is less than the current discharge dynamic voltage threshold and the current discharge SOC is greater than the calibration point discharge SOC, then the current discharge SOC is reduced by a second preset proportional coefficient according to a preset period until the calibrated current discharge SOC is equal to the calibration point discharge SOC. If the minimum single-cell voltage is greater than the current discharge dynamic voltage threshold and the current discharge SOC is less than the calibration point discharge SOC, then the discharge SOC rate is reduced to the discharge SOC rate of the first preset proportional coefficient, and the sum of the current discharge SOC and the product of the first preset proportional coefficient and the discharge SOC rate is determined as the calibrated current discharge SOC, until the minimum single-cell voltage is equal to the current discharge dynamic voltage threshold.

6. The method according to claim 1, characterized in that, The method further includes: After the battery starts charging, when the current charging SOC reaches the first calibration point charging SOC, the first current dynamic voltage value of the battery is detected according to the preset SOC threshold step size of the battery, and the second current dynamic voltage value of multiple calibration points is detected. Based on the first current dynamic voltage value, the second current dynamic voltage value, and the pre-stored calibration dynamic voltage, determine whether the battery voltage value is normal; If the voltage is normal, then the steps of obtaining the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of battery charging are executed. If the current charging SOC is equal to the maximum preset SOC threshold and the battery is fully charged, then the target preset SOC is determined as the calibrated current charging SOC.

7. The method according to claim 6, characterized in that, The step of determining whether the battery voltage is normal based on the first current dynamic voltage value, the second current dynamic voltage value, and the pre-stored calibration dynamic voltage includes: The first difference between the first current dynamic voltage value and the first difference between the pre-stored calibrated dynamic voltage, and the second difference between the second current dynamic voltage value and the pre-stored calibrated dynamic voltage, are compared with a preset difference threshold. If both the first difference and the second difference are greater than the preset difference threshold, the battery voltage is determined to be abnormal; otherwise, the voltage is determined to be normal.

8. The method according to claim 1, characterized in that, The method further includes: During the battery discharge process, if the current charging SOC is equal to the minimum preset SOC threshold and the battery is fully discharged, then 0% is determined as the calibrated current charging SOC.

9. A device for calibrating battery SOC, characterized in that, The device includes: The first acquisition module is used to acquire the current charging temperature value, maximum single cell voltage, current charging SOC and charging current value of the battery within the current preset SOC threshold step size of battery charging. The first calibration module is used to determine the calibrated current charging SOC based on the current charging temperature value, the maximum single-cell voltage, the current charging SOC, and the charging current value, until the maximum single-cell voltage or the current charging SOC meets the calibration requirements. The second acquisition module is used to acquire the current discharge temperature value, minimum single cell voltage, current discharge SOC and discharge current value of the battery within the current preset SOC threshold step of the battery discharge. The second calibration module is used to determine the calibrated current discharge SOC based on the current discharge temperature value, the minimum single-cell voltage, the current discharge SOC, and the discharge current value, until the minimum single-cell voltage or the current discharge SOC meets the calibration requirements.

10. The apparatus according to claim 9, characterized in that, The first calibration module is specifically used for: If the charging current value is not within the preset charging current threshold range, the battery current is determined to be abnormal; otherwise, the current charging dynamic voltage curve corresponding to the current charging temperature value is queried from the pre-stored correspondence between charging temperature value and charging dynamic voltage curve; the charging dynamic voltage curve is composed of multiple charging dynamic voltage thresholds of various step sizes, and the charging dynamic voltage threshold corresponds to the battery's calibration point charging SOC. Based on the maximum single-cell voltage, the current charging SOC, the calibration point charging SOC, and the charging dynamic voltage threshold in the current charging dynamic voltage curve, the calibrated current charging SOC is determined until the maximum single-cell voltage or the current charging SOC meets the calibration requirements.

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