Method for dynamically correcting state of charge, apparatus, and electronic device

Abstract

A method for dynamically correcting a state of charge, an apparatus, and an electronic device. The method comprises: calculating the currently available state of charge of a battery pack according to an ampere-hour integral (S110); synchronously updating the displayed state of charge to the currently available state of charge (S120); determining a correction type for the battery pack, and correcting the currently available state of charge according to the correction type to obtain a corrected available state of charge (S130).

Description

Method, device and electronic equipment for dynamically correcting state of charge

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 27, 2023, with application number 202311830691.3. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of battery technology, and specifically to a method, device, and electronic device for dynamically correcting the state of charge. Background Art

[0003] With the market's growing interest in new energy vehicles and energy storage electronics, battery state-of-charge (SOC) has drawn significant attention. Appropriate SOC estimation methods can improve SOC estimation accuracy and remaining battery life, effectively preventing overcharging and over-discharging, and minimizing damage to the battery caused by charging.

[0004] Related SOC estimation methods include Kalman filtering and neural networks. Kalman filtering is suitable for linear systems. However, since battery SOC estimation is nonlinear, extended Kalman filtering (EKF) and unscended Kalman filtering (UKF) are used based on the Kalman filtering principle for nonlinear system estimation. Technical issues

[0005] Neural network methods require a large number of training samples, are complex, and are significantly affected by battery aging. For battery systems with single or multi-cluster packs, using algorithm training for SOC estimation is often difficult due to the large amount of training required and the complexity of the algorithm, which can lead to large errors and is not conducive to practical engineering practice and widespread production. Solution

[0006] In a first aspect, an embodiment of the present application provides a method for dynamically correcting a state of charge, comprising:

[0007] Calculate the current available state of charge of the battery pack based on the ampere-hour integration;

[0008] Synchronously updating the displayed state of charge to the current available state of charge;

[0009] determining a correction type of the battery pack, and correcting the current available state of charge according to the correction type to obtain a corrected available state of charge;

[0010] In the charging state, in response to the displayed state of charge being greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using a first correction rate; in response to the displayed state of charge being less than the corrected available state of charge, the displayed state of charge is corrected and displayed using a second correction rate;

[0011] In the discharge state, in response to the displayed state of charge being greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using a second correction rate; in response to the displayed state of charge being less than the corrected available state of charge, the displayed state of charge is corrected and displayed using a first correction rate; wherein the first correction rate is less than the second correction rate.

[0012] In a second aspect, an embodiment of the present application provides a device for dynamically correcting a state of charge, comprising:

[0013] An ampere-hour integration module is configured to calculate the current available state of charge of the battery pack based on the ampere-hour integration;

[0014] a display smoothing module configured to synchronously update the displayed state of charge to the current available state of charge;

[0015] a correction module configured to determine a correction type of the battery pack, and correct the current available state of charge according to the correction type to obtain a corrected available state of charge;

[0016] In the charging state, in response to the displayed state of charge being greater than the corrected available state of charge, the display smoothing module is further configured to correct the displayed state of charge using a first correction rate; and in response to the displayed state of charge being less than the corrected available state of charge, the display smoothing module is further configured to correct the displayed state of charge using a second correction rate.

[0017] In the discharge state, in response to the displayed state of charge being greater than the corrected available state of charge, it is also configured to correct and display the displayed state of charge using a second correction rate; in response to the displayed state of charge being less than the corrected available state of charge, it is also configured to correct the displayed state of charge using a first correction rate; wherein the first correction rate is displayed less than the second correction rate.

[0018] In a third aspect, an embodiment of the present application provides an electronic device, comprising:

[0019] at least one processor; and

[0020] a memory communicatively connected to the at least one processor; wherein,

[0021] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for dynamically correcting the state of charge described in any embodiment of the present application. Beneficial effects

[0022] The technical solution provided in the present application adopts the ampere-hour integration method to estimate the SOC, and then determines the correction type of the battery pack according to the energy storage working condition of the battery pack, and corrects the current available SOC according to the correction type to obtain the corrected available SOC. The available SOC jumps directly when the correction is generated, and the displayed SOC does not jump directly. Instead, different correction rates are used to smoothly change the displayed SOC to the available SOC value during the charging and discharging process, so that the battery SOC of the battery cluster / group can indicate the actual state of the current SOC remaining power, meet the estimation accuracy requirements, and reduce the complexity of SOC estimation based on the ampere-hour integration method, reduce the application cost of engineering practice, and improve actual applicability in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic flow chart of a method for dynamically correcting state of charge provided in an embodiment of the present application;

[0024] FIG2 is a flow chart of another method for dynamically correcting the state of charge provided in an embodiment of the present application;

[0025] FIG3 is a flow chart of a method for correcting a current available state of charge to obtain a corrected available state of charge, provided in an embodiment of the present application;

[0026] FIG4 is a flow chart of another method for correcting a current available state of charge to obtain a corrected available state of charge, provided in an embodiment of the present application;

[0027] FIG5 is a flow chart of another method for correcting a current available state of charge to obtain a corrected available state of charge, provided in an embodiment of the present application;

[0028] FIG6 is a schematic structural diagram of a device for dynamically correcting state of charge provided in an embodiment of the present application;

[0029] FIG7 is a schematic structural diagram of another device for dynamically correcting the state of charge according to an embodiment of the present application;

[0030] FIG8 is a schematic structural diagram of an electronic device provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0031] FIG1 is a flow chart of a method for dynamically correcting the state of charge provided by an embodiment of the present application. This embodiment is applicable to the case of dynamic correction of battery SOC. The method can be performed by a dynamic state of charge correction device, which can be implemented in hardware and / or software. The method includes the following steps:

[0032] S110, calculating the current available state of charge of the battery pack based on the ampere-hour integral;

[0033] The ampere-hour integration method integrates the current flowing into or out of the battery with time. Based on the battery's initial state of charge (SOC) value, the remaining charge in the battery at that moment can be calculated. In other words, the ampere-hour integration method integrates the current during the charge and discharge process and divides it by the battery's total capacity to obtain the corresponding SOC value. Compared to other algorithms, the ampere-hour integration method is simpler and easier to implement. For example, by calculating the integral of the current and the charge and discharge time over a preset time period, such as 500ms, the capacity change Q1 is obtained. The capacity change Q1 is then divided by the rated capacity Q0 to obtain the change in state of charge (ΔSOC). When a battery pack is discharging, the discharge current is positive, and the calculated ampere-hour integration is a positive number, meaning that ΔSOC is a positive number. The current available state of charge can be expressed as SOC = SOC0 - ΔSOC, where SOC0 is the initial SOC value. During discharge, the current available state of charge is limited to a minimum of 0%. In other words, the displayed SOC of the battery pack during discharge cannot be less than 0%. When a battery pack is charging, the charging current is negative, and the calculated ampere-hour integral is a negative number, that is, ΔSOC is a negative number. The current available state of charge can be expressed as SOC = SOC0 − ΔSOC, where SOC0 is the initial SOC value. During charging, the current available state of charge is limited to 100%. In other words, the maximum SOC displayed on the battery pack's state of charge cannot exceed 100%.

[0034] S120 , synchronously updating the displayed state of charge to the current available state of charge.

[0035] The state of charge display is updated synchronously to show the current available state of charge in real time. This allows real-time feedback data to be displayed on the device, improving the user experience.

[0036] S130 , determining a correction type of the battery pack, and correcting the current available state of charge according to the correction type to obtain a corrected available state of charge.

[0037] The accuracy of the ampere-hour integration algorithm depends on the precision of the current collected by the current sensor. To reduce the error introduced by the current sensor, the current available state of charge (SOC) needs to be corrected. First, the conditions for entering the correction process are determined. For example, the correction process determines whether the entire correction process is complete, and a series of judgment conditions, such as cell temperature, maximum cell voltage, minimum cell voltage, and whether the battery management system (BMS) startup time is normal, are determined. If these conditions are met, the correction process can be invoked. Exemplary SOC correction types include static open-circuit voltage correction, pre-charge correction, full-charge correction, static low-end correction, extreme low-end correction, extreme high-end correction, and temperature-dependent battery capacity correction. Using these different correction types, the current available state of charge is corrected to obtain a corrected available state of charge.

[0038] S140. In the charging state, if the displayed state of charge is greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using a first correction rate; if the displayed state of charge is less than the corrected available state of charge, the displayed state of charge is corrected and displayed using a second correction rate;

[0039] In the discharge state, if the displayed state of charge is greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using the second correction rate; if the displayed state of charge is less than the corrected available state of charge, the displayed state of charge is corrected and displayed using the first correction rate; wherein the first correction rate is less than the second correction rate.

[0040] Since the corrected available state of charge is not completely consistent with the current available state of charge obtained by ampere-hour integration, the available SOC will jump after each correction. In the usual SOC display method, an SOC display value presented to the end user is added, namely the display state of charge (display SOC). In other words, the available SOC jumps directly when the correction is made, but the displayed SOC does not jump directly. Instead, the displayed SOC smoothly transitions to the corrected available SOC. In other words, the data with upward fluctuations is pulled down, and the data with downward fluctuations is pulled up, so that the data is as continuous as possible, rather than discrete, to prevent jumps. When the available SOC is corrected to 100%, it is necessary to jump directly to 100% when displaying the SOC.

[0041] When there is current, the displayed SOC needs to follow the change of the available SOC and automatically adjust the acceleration correction rate according to different differences. For example, in the charging condition where 10% < SOC < 90%, if the displayed SOC is greater than the corrected available SOC, in order to make the displayed SOC closer to the actual value and have higher accuracy, display correction is required. The displayed state of charge is corrected and displayed at the first correction rate. Exemplarily, the first correction rate is 0.25. That is to say, the following speed of the displayed state of charge is slowed down, so as to wait for the supplementary charge to reach the displayed SOC. When the displayed SOC is approximately equal to the corrected available SOC, the correction rate can be no longer set. When the displayed SOC is less than the corrected available SOC, the displayed state of charge is corrected and displayed at the second correction rate. Exemplarily, the second correction rate is 4. That is to say, the following speed is increased, so as to quickly reach the corrected available SOC.

[0042] In the discharging condition where 10% < SOC < 90%, if the displayed SOC is greater than the corrected available SOC, in order to make the displayed SOC closer to the actual value and have higher accuracy, display correction is required. The displayed state of charge is corrected and displayed at the second correction rate. Exemplarily, the second correction rate is 4. That is to say, the following speed of the displayed state of charge is increased, so as to catch up with the displayed value of the available SOC. When the displayed SOC is approximately equal to the corrected available SOC, the correction rate can be no longer set. When the displayed SOC is less than the corrected available SOC, the displayed state of charge is corrected and displayed at the first correction rate. Exemplarily, the first correction rate is 0.25. That is to say, the following speed of the displayed state of charge is reduced, so as to wait for the available SOC to release charge and then make the value of the displayed SOC catch up with the value of the available SOC.

[0043] In the embodiments of the present application, the ampere-hour integration method is used to estimate the SOC, and then according to the energy storage condition of the battery pack, the correction type of the battery pack is determined, and the current available SOC is corrected according to the correction type to obtain the corrected available SOC. The available SOC jumps directly when correction occurs, and the displayed SOC does not jump directly, but smoothly changes the displayed SOC to the available SOC value during the charge and discharge process using different correction rates, so that the battery SOC of the battery cluster / group can indicate the true state of the current remaining SOC, meet the estimation accuracy requirements, and reduce the complexity of SOC estimation based on the ampere-hour integration method, reduce the application cost of engineering practice, and improve the practical applicability of production.

[0044] In some embodiments, FIG. 2 is a schematic flow chart of another method for dynamically correcting the state of charge provided by the embodiments of the present application. Referring to FIG. 2, the method includes the following steps:

[0045] S210. Obtain the accumulated charge and discharge ampere-hours of the battery pack.

[0046] The accumulated charge and discharge ampere-hours are typically stored in the BMS and can be directly read. During the charge and discharge process, the charge and discharge ampere-hours are constantly changing. In some embodiments, after obtaining the current accumulated charge and discharge ampere-hours, they are compared with the previously stored backup ampere-hours to determine the change between the two. If the change is normal, the stored value is updated to the accumulated charge and discharge ampere-hours to ensure real-time data.

[0047] S220: Calculate the change in ampere-hours within a preset time period according to the ampere-hour integration method.

[0048] The integral of the current and the charge / discharge time within a preset time, such as 500ms, is: where i is the current and t is the charge / discharge time. Thus, the capacity change Q1, i.e., the change in ampere-hours, is obtained.

[0049] S230: Obtain the current ampere-hours according to the accumulated charge and discharge ampere-hours and the change value.

[0050] The current ampere-hours are obtained by summing the accumulated charge and discharge ampere-hours and the change in ampere-hours.

[0051] S240: Calculate the current available state of charge based on the current ampere-hours and the rated ampere-hours.

[0052] The change in state of charge (ΔSOC) is calculated by ratioing the change in capacity (Q1), or ampere-hours, to the rated capacity (Q0), or rated ampere-hours. When the battery pack is discharging, the discharge current is positive, and the integral of the ampere-hours is positive, meaning ΔSOC is positive. The current available state of charge can be expressed as SOC = SOC0 − ΔSOC, where SOC0 is the initial SOC value. During discharge, the current available state of charge is limited to a minimum of 0%. In other words, the displayed SOC during the discharge state of the battery pack cannot be less than 0%. When the battery pack is charging, the charge current is negative, and the integral of the ampere-hours is negative, meaning ΔSOC is negative. The current available state of charge can be expressed as SOC = SOC0 − ΔSOC, where SOC0 is the initial SOC value. During charging, the current available state of charge is limited to a maximum of 100%. In other words, the displayed SOC during the charge state of the battery pack cannot exceed 100%.

[0053] S250: Synchronously update the displayed state of charge to the current available state of charge.

[0054] S260: Determine the correction type of the battery pack, and correct the current available state of charge according to the correction type to obtain a corrected available state of charge.

[0055] S270: In the charging state, if the displayed state of charge is greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using a first correction rate; if the displayed state of charge is less than the corrected available state of charge, the displayed state of charge is corrected and displayed using a second correction rate;

[0056] In the discharge state, if the displayed state of charge is greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using the second correction rate; if the displayed state of charge is less than the corrected available state of charge, the displayed state of charge is corrected and displayed using the first correction rate; wherein the first correction rate is less than the second correction rate.

[0057] In some embodiments, the correction types include at least one or more of static open circuit voltage correction, pre-charge correction, full charge correction, static low end correction, extreme low end correction, extreme high end correction, and temperature correction of battery capacity.

[0058] In some embodiments, static open-circuit voltage (OCV) correction combined with the ampere-hour integration method can significantly improve SOC estimation accuracy. The open-circuit voltage method uses only the discharge OCV for estimation, considering OCV-SOC curves at different temperatures or at a specific temperature. The open-circuit voltage method determines the available SOC based on a table of open-circuit voltage and OCV-SOC relationships after the battery's charge and discharge cycles have completed and its voltage characteristics have stabilized. Static OCV correction triggers when the battery pack has been idle for a certain period of time (e.g., more than one hour), the time between the BMS powering down from low voltage and the next power-on exceeds one hour (power-on static OCV correction), or the BMS powering down from low voltage but with current less than 0.1C for more than one hour (low-current static OCV correction). Power-on static OCV correction must be triggered within 600ms after the power-on automatic addressing is completed; low-current static OCV correction is triggered 10s after the automatic addressing is completed.

[0059] In addition, the battery needs to be in a discharged state before it is fully rested, that is, it must be discharged to the ampere-hour corresponding to at least 1% SOC. When the SOC is discharged to 1%, the battery is considered to be in a discharged state, and the discharge OCV-SOC curve can be used for correction. Discharge state judgment logic: The cumulative charge and discharge ampere-hours, that is, the ampere-hours corresponding to each change in SOC by a certain value (for example, 1.5% SOC), trigger a judgment. If the cumulative discharge ampere-hour change is greater than or equal to the ampere-hour corresponding to 1% SOC, the battery is considered to be in a discharged state.

[0060] If the above determination conditions are met, the correction type can be determined to perform static OCV correction. FIG3 is a flow chart of a method for correcting the current available state of charge to obtain a corrected available state of charge, provided in an embodiment of the present application. The method includes the following steps:

[0061] S310: Obtain the open circuit voltage of the battery pack at a preset temperature.

[0062] S320 , selecting a corresponding state of charge according to a state of charge and open circuit voltage fitting curve.

[0063] S330 : Correct the current available state of charge according to the corresponding state of charge to obtain a corrected available state of charge.

[0064] Since the battery pack is in a static state, the open circuit voltage of the battery can be directly measured at a preset temperature, and the corresponding SOC can be selected according to the state of charge and open circuit voltage fitting curve. The state of charge and open circuit voltage fitting curve can be pre-measured according to the measurement fitting method of the relevant technology, which will not be described in detail here. The state of charge and open circuit voltage fitting curve are stored as storage data in the electronic device, and the electronic device can directly retrieve the fitting curve data for matching to obtain the corresponding SOC. The available SOC calculated by the ampere-hour integration method is compared with the corresponding SOC obtained according to the fitting curve data. If the difference between the two is within the allowable range, the available SOC does not need to be corrected. If the difference between the two exceeds the allowable range, the available SOC will be corrected to the corresponding SOC obtained according to the fitting curve data.

[0065] In some embodiments, after the battery pack enters the charging state for a certain period of time, for example, 5 minutes, if the minimum temperature is greater than 0°C and continues for a certain period of time, for example, 30 seconds, and the configured relationship data between the charge rate and the cell voltage value is satisfied, a pre-charge correction of the SOC will be performed to reduce the SOC error. For example, Table 1 provides a relationship data between the charge rate and the average cell voltage for an embodiment of the present application. The relationship data between the charge rate and the cell voltage value can be enriched by measuring the charge rate and cell voltage values ​​at different SOCs multiple times.

[0066] Table 1 provides a relationship between the charging rate and the average cell voltage (temperature 10-20°C) for the embodiment of the present application.

[0067]

[0068] When performing charging pre-correction, FIG4 is a flow chart of another method for correcting the current available state of charge to obtain a corrected available state of charge according to an embodiment of the present application. Referring to FIG4 , the method includes the following steps:

[0069] S410. Select at least one high-end state-of-charge calibration point and at least one low-end state-of-charge calibration point based on a data relationship between an average cell voltage and the state of charge in the battery pack at different preset charging rates; wherein the state-of-charge value of the high-end state-of-charge calibration point is greater than the state-of-charge value of the low-end state-of-charge calibration point.

[0070] Based on the aforementioned relationship between the average cell voltage and state of charge in the battery pack, at least one high-end state of charge calibration point is selected near 100% SOC, for example, 94% and 87% SOC. Similarly, at least one low-end state of charge calibration point is selected near 0% SOC, for example, 22% and 7% SOC. This allows corrections to be made at both ends of the available SOC, namely, those near 100% SOC and those near 0% SOC, thereby increasing the accuracy of the SOC values ​​at both ends.

[0071] S420, comparing the maximum cell voltage value in the battery pack with the average cell voltage corresponding to the high-end state of charge calibration point; if the maximum cell voltage value is greater than the average cell voltage corresponding to the high-end state of charge calibration point, and the current available state of charge is less than the state of charge value at the high-end state of charge calibration point, correcting the current available state of charge to the state of charge value at the high-end state of charge calibration point;

[0072] Alternatively, the minimum cell voltage value in the battery pack is compared with the average cell voltage corresponding to the low-end state of charge calibration point; if the maximum cell voltage value is greater than the average cell voltage corresponding to the low-end state of charge calibration point, and the current available state of charge is less than the state of charge value of the low-end state of charge calibration point, then the current available state of charge is corrected to the state of charge value of the low-end state of charge calibration point.

[0073] The high-end SOC calibration point is determined using the maximum cell voltage in the battery pack. If the maximum cell voltage is greater than the voltage corresponding to the high-end SOC calibration point, but the available SOC is lower than the SOC corresponding to the high-end SOC calibration point, the available SOC is corrected to the SOC corresponding to the high-end SOC calibration point, thereby making the high-end SOC closer to the true SOC. The low-end SOC calibration point is determined using the minimum cell voltage in the battery pack. If the minimum cell voltage is greater than the voltage corresponding to the low-end SOC calibration point, but the available SOC is lower than the SOC corresponding to the low-end SOC calibration point, the available SOC is corrected to the SOC corresponding to the low-end SOC calibration point, thereby making the low-end SOC closer to the true SOC.

[0074] In some embodiments, when a battery pack is charging normally according to a charging strategy and the charge current drops to the full charge stage, a SOC full charge correction is triggered to reduce SOC errors. If the average cell voltage is greater than a configured threshold, such as 3.38V, the battery is fully charged, and the available SOC is directly corrected to 100%, and the displayed SOC also changes rapidly to 100%.

[0075] In some embodiments, when the battery changes from a discharge state to a static state, the characteristics of the battery show that the battery will have a rebound voltage. The real-time monitored single cell voltage plus the accurate rebound voltage value can be close to the OCV voltage, but the accurate rebound voltage is not easy to obtain. In order to conservatively correct the SOC and reduce some SOC errors, the rebound voltage can be taken as a larger value to perform a static low-end correction of the SOC. By determining the triggering conditions for the static low-end correction, for example, when the battery management system BMS is powered on at low voltage for a certain period of time (for example, 5 minutes), there is no current greater than 1C within 30s, the current is <0.1C for more than 15s, the minimum voltage change within 200ms is less than 50mv, the minimum temperature is ≥0°C; the minimum voltage is less than the configured minimum voltage threshold (for example, 3.2V), and the average voltage is less than the configured average voltage threshold (for example, 3.2V). It is determined that the correction type used is a static low-end correction. Figure 5 is another flow chart of a method for correcting the current available state of charge to obtain a corrected available state of charge according to an embodiment of the present application. Referring to Figure 5, the method includes the following steps:

[0076] S510 : Obtain a rebound voltage of the battery pack when the battery pack changes from a discharge state to a static state.

[0077] S520 , adding the rebound voltage to the minimum cell voltage value in the battery pack to obtain a reference voltage.

[0078] S530 : Select a target state of charge corresponding to a reference voltage according to a state of charge and an open circuit voltage fitting curve.

[0079] S540: If the target SOC is less than the preset reference SOC, and the current available SOC is greater than or equal to the sum of the target SOC and the error threshold, correct the current available SOC to the target SOC.

[0080] The reference voltage is obtained by adding the rebound voltage to the minimum cell voltage. The state of charge corresponding to the reference voltage, i.e., the target SOC, is obtained by fitting a curve to the state of charge and open-circuit voltage or by looking up the state of charge and open-circuit voltage in a table. If the target SOC is lower than the configured reference SOC threshold (to ensure accuracy on the low-end side of the SOC, the reference SOC threshold can be set to 25%), and the current available SOC ≥ the target SOC + an error threshold (an exemplary error threshold of 3% in the embodiment of the present application), a static low-end correction is performed if these conditions are met. For example, if the current available SOC is 50% and the actual battery SOC is 15%, but the rebound voltage value is too high, resulting in a target SOC of 20% obtained by looking up the table based on the minimum cell voltage plus the rebound voltage, the state of charge, and open-circuit voltage. If the target SOC is lower than the configured reference SOC threshold of 25%, and the current available SOC 50% ≥ the target SOC 20% + 3%, the available SOC is corrected from 50% to 20%.

[0081] In some embodiments, if the minimum cell voltage in a battery pack is less than a preset extreme low-end correction threshold for a first period of time, an extreme low-end correction is performed, correcting the current available state of charge to 0%. For example, if the minimum cell voltage is less than the preset extreme low-end correction threshold (e.g., 2.5V) for 60 seconds, the battery pack is considered to have completed discharge at the low point, and the available SOC is corrected to 0%.

[0082] In some embodiments, if the maximum cell voltage in the battery pack is less than a preset upper limit correction threshold for a second period of time, an upper limit correction is performed to correct the current available SOC to 100%. For example, if the maximum cell voltage is greater than a preset upper limit correction threshold (e.g., 3.65V) for 60 seconds, the battery pack is considered to have completed charging to the upper limit, and the available SOC is corrected to 100%.

[0083] In some embodiments, the correction of battery capacity to temperature can be performed based on the available capacity data of battery cells at different temperatures provided by the battery manufacturer. Generally, the correction coefficient is 100% when the temperature is greater than 25°C.

[0084] Table 2 shows the relationship between the available capacity of the battery and the correction factor at different temperatures

[0085]

[0086] If the time between the last power-on and power-off exceeds 5 minutes, the battery management system (BMS) will trigger the temperature battery capacity correction function after power-on. The BMS will correct the battery's available capacity and available SOC based on the minimum temperature. During subsequent BMS operation, it will determine whether the minimum temperature change is greater than or equal to 2°C every 5 minutes. If the minimum temperature change is greater than or equal to 2°C, the temperature battery capacity correction function will be triggered, and the available capacity data of the battery cells at different temperatures will be corrected. The available SOC will also be corrected synchronously.

[0087] FIG6 is a schematic structural diagram of a device for dynamically correcting state of charge according to an embodiment of the present application, and includes:

[0088] An ampere-hour integration module is configured to calculate the current available state of charge of the battery pack based on the ampere-hour integration;

[0089] A display smoothing module configured to synchronize the displayed state of charge with the current available state of charge;

[0090] a correction module configured to determine a correction type of the battery pack, and correct the current available state of charge according to the correction type to obtain a corrected available state of charge;

[0091] In the charging state, if the displayed state of charge is greater than the corrected available state of charge, the display smoothing module is further configured to correct the displayed state of charge using a first correction rate; if the displayed state of charge is less than the corrected available state of charge, the display smoothing module is further configured to correct the displayed state of charge using a second correction rate;

[0092] In the discharge state, if the displayed state of charge is greater than the corrected available state of charge, it is also set to correct the displayed state of charge using the second correction rate; if the displayed state of charge is less than the corrected available state of charge, it is also set to correct the displayed state of charge using the first correction rate; wherein the first correction rate is displayed less than the second correction rate.

[0093] The ampere-hour integration method integrates the current flowing into or out of the battery with time. Based on the battery's initial state of charge (SOC) value, the remaining charge in the battery at that moment can be calculated. Specifically, the ampere-hour integration module integrates the current during the charge and discharge processes and divides it by the battery's total capacity to determine the corresponding SOC value. Compared to other algorithms, the ampere-hour integration method is simpler and easier to implement. For example, the ampere-hour integration module calculates the capacity change Q1 by integrating the current and charge / discharge time over a preset time period, such as 500ms. This capacity change Q1 is then compared to the rated capacity Q0 to determine the change in state of charge (ΔSOC). When a battery pack is discharging, the discharge current is positive, and the calculated ampere-hour integration is a positive number, meaning that ΔSOC is positive. The current available state of charge can be expressed as SOC = SOC0 − ΔSOC, where SOC0 is the initial SOC value. During discharge, the current available state of charge is limited to a minimum of 0%. In other words, the displayed SOC of the battery pack during discharge cannot be less than 0%. When a battery pack is charging, the charging current is negative, and the calculated ampere-hour integral is a negative number, that is, ΔSOC is a negative number. The current available state of charge can be expressed as SOC = SOC0 − ΔSOC, where SOC0 is the initial SOC value. During charging, the current available state of charge is limited to 100%. In other words, the maximum SOC displayed on the battery pack's state of charge cannot exceed 100%.

[0094] The display smoothing module synchronously updates the displayed state of charge to display the current available state of charge in real time. This allows real-time feedback data to be displayed on the device, improving the user experience.

[0095] During the correction process, the correction module determines whether the entire correction is complete, cell temperature, maximum and minimum cell voltage values, and whether the BMS startup time is normal. If these conditions are met, the correction program is invoked. Exemplary SOC correction types include static open-circuit voltage correction, pre-charge correction, full-charge correction, static low-end correction, extreme low-end correction, extreme high-end correction, and temperature-dependent battery capacity correction, or a combination thereof. The correction module uses these different correction types to modify the current available state of charge (USC) to obtain a corrected USC.

[0096] Since the corrected available state of charge is not exactly the same as the current available state of charge obtained by ampere-hour integration, the available SOC jumps each time it is corrected. In the usual SOC display method, an SOC display value presented to the end user is added, that is, the displayed state of charge (displayed SOC). That is to say, when the available SOC is corrected, it jumps directly, but the displayed SOC does not jump directly. Instead, the displayed SOC is smoothly transitioned to the corrected available SOC. That is to say, the display smoothing module pulls down the data with fluctuations above and pulls up the data with fluctuations below, making the data as continuous as possible rather than discrete, to prevent jumps. It should be noted that when the available SOC is corrected to 100%, the displayed SOC jumps directly to 100%.

[0097] Therefore, when there is current, the displayed SOC needs to follow the change of the available SOC and automatically adjust the acceleration correction rate according to different differences. For example, in the charging condition where 10% < SOC < 90%, if the displayed SOC is greater than the corrected available SOC, in order to make the displayed SOC closer to the actual value and have higher accuracy, display correction is required. The display smoothing module corrects and displays the displayed SOC at the first correction rate. Exemplarily, the first correction rate is 0.25. That is to say, the following speed of the displayed state of charge is slowed down, so as to wait for the supplementary charge to reach the displayed SOC. When the displayed SOC is approximately equal to the corrected available SOC, the display smoothing module can stop setting the correction rate. When the displayed SOC is less than the corrected available SOC, the display smoothing module corrects and displays the displayed SOC at the second correction rate. Exemplarily, the second correction rate is 4. That is to say, the following speed is increased, so as to quickly reach the corrected available SOC.

[0098] In the discharging condition where 10% < SOC < 90%, if the displayed SOC is greater than the corrected available SOC, in order to make the displayed SOC closer to the actual value and have higher accuracy, display correction is required. The display smoothing module corrects and displays the displayed SOC at the second correction rate. Exemplarily, the second correction rate is 4. That is to say, the following speed of the displayed state of charge is increased, so as to catch up with the available SOC display value. When the displayed SOC is approximately equal to the corrected available SOC, the display smoothing module can stop setting the correction rate. When the displayed SOC is less than the corrected available SOC, the display smoothing module corrects and displays the displayed SOC at the first correction rate. Exemplarily, the first correction rate is 0.25. That is to say, the following speed of the displayed state of charge is reduced, so as to wait for the available SOC to release charge and then make the value of the displayed SOC catch up with the value of the available SOC.

[0099] In the embodiment of the present application, the ampere-hour integration module uses the ampere-hour integration method to estimate the SOC, and the correction module determines the correction type of the battery pack according to the energy storage working condition of the battery pack, and corrects the current available SOC according to the correction type to obtain the corrected available SOC. The available SOC jumps directly when the correction is generated, and the displayed SOC does not jump directly. Instead, different correction rates are set by the display smoothing module to smoothly change the displayed SOC to the available SOC value during the charging and discharging process, so that the battery SOC of the battery cluster / group can indicate the actual state of the current SOC remaining power, meet the estimation accuracy requirements, and reduce the complexity of SOC estimation based on the ampere-hour integration method, reduce the application cost of engineering practice, and improve actual applicability in production.

[0100] Based on the above embodiments, FIG7 is a structural schematic diagram of another device for dynamically correcting the state of charge according to an embodiment of the present application. Referring to FIG7 , the device for dynamically correcting the state of charge may further include an SOC fault diagnosis module 640, an SOC-OCV table lookup module 650, and an SOH calculation module 660. The SOC fault diagnosis module 640 is configured to diagnose SOC-related faults. The SOC-OCV table lookup module 650 is configured to obtain OCV values ​​at different temperatures and different SOCs through cell testing, organize the OCV-SOC data table, and perform table lookup correction according to the correction instruction during the correction process. The SOH calculation module 660 is configured to calculate the battery state of health (SOH) based on parameters such as the cumulative total discharge capacity, the number of battery cycle life, the actual discharge capacity, and the rated capacity.

[0101] FIG8 shows a block diagram of an electronic device 10 that can be used to implement an embodiment of the present application. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are for example only and are not intended to limit the implementation of the present application described and / or claimed herein.

[0102] As shown in Figure 8, electronic device 10 includes at least one processor 11 and memory, such as read-only memory (ROM) 12 and random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. Processor 11 can perform various appropriate actions and processes based on the computer programs stored in ROM 12 or loaded from storage unit 18 into RAM 13. RAM 13 can also store various programs and data required for the operation of electronic device 10. Processor 11, ROM 12, and RAM 13 are interconnected via bus 14. An input / output (I / O) interface 15 is also connected to bus 14.

[0103] Multiple components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0104] Processor 11 can be a variety of general-purpose and / or specialized processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU) 121, a graphics processing unit (GPU) 121, various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any other suitable processor, controller, microcontroller, etc. Processor 11 executes the various methods and processes described above, such as the method for dynamically correcting the state of charge.

[0105] In some embodiments, the thin film measurement method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the method for dynamically correcting the state of charge described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the method for dynamically correcting the state of charge through any other suitable means (e.g., via firmware).

[0106] Computer programs for implementing the methods of the present application may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

Claims

1. A method for dynamically correcting a state of charge, comprising: Calculate the current available state of charge of the battery pack based on the ampere-hour integration; Synchronously updating the displayed state of charge to the current available state of charge; Determining a correction type of the battery pack, and correcting the current available state of charge according to the correction type to obtain the corrected available state of charge; In the charging state, in response to the displayed state of charge being greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using a first correction rate; In response to the displayed state of charge being less than the corrected available state of charge, the displayed state of charge is corrected and displayed using a second correction rate; In the discharge state, in response to the displayed state of charge being greater than the corrected available state of charge, the displayed state of charge is corrected and displayed using a second correction rate; In response to the displayed state of charge being less than the corrected available state of charge, the displayed state of charge is corrected and displayed using a first correction rate; wherein the first correction rate is less than the second correction rate.

2. The method for dynamically correcting the state of charge according to claim 1, wherein: The calculating the current available state of charge of the battery pack according to the ampere-hour integration includes: Obtaining the accumulated charge and discharge ampere-hours of the battery pack; Calculate the change value of the ampere-hour within the preset time according to the ampere-hour integration method; Obtaining a current ampere-hour according to the accumulated charge and discharge ampere-hours and the change value; The current available state of charge is calculated based on the current ampere-hours and the rated ampere-hours.

3. The method for dynamically correcting the state of charge according to any one of claims 1 to 2, wherein: The correction type includes at least one or more of static open circuit voltage correction, charge pre-correction, static low-end correction, extreme low-end correction and extreme high-end correction.

4. The method for dynamically correcting the state of charge according to claim 3, wherein: In response to determining that the correction type is static open circuit voltage correction, correcting the current available state of charge according to the correction type to obtain the corrected available state of charge includes: Obtaining an open circuit voltage of the battery pack at a preset temperature; Select the corresponding state of charge according to the state of charge and open circuit voltage fitting curve; The current available state of charge is corrected according to the corresponding state of charge to obtain the corrected available state of charge.

5. The method for dynamically correcting the state of charge according to claim 3, wherein: In response to determining that the correction type is charging pre-correction, correcting the current available state of charge according to the correction type to obtain the corrected available state of charge includes: According to the data relationship between the average single cell voltage and the state of charge in the battery pack at different preset charging rates, at least one high-end state of charge calibration point and at least one low-end state of charge calibration point are selected; wherein the state of charge value of the high-end state of charge calibration point is greater than the state of charge value of the low-end state of charge calibration point; Comparing the maximum cell voltage value in the battery pack with the average cell voltage corresponding to the high-end state of charge calibration point; in response to the maximum cell voltage value being greater than the average cell voltage corresponding to the high-end state of charge calibration point, and the current available state of charge being less than the state of charge value of the high-end state of charge calibration point, correcting the current available state of charge to the state of charge value of the high-end state of charge calibration point; Or compare the minimum single cell voltage value in the battery pack with the average single cell voltage corresponding to the low-end state of charge calibration point; in response to the maximum single cell voltage value being greater than the average single cell voltage corresponding to the low-end state of charge calibration point, the current available state of charge is less than the state of charge value of the low-end state of charge calibration point, and the current available state of charge is corrected to the state of charge value of the low-end state of charge calibration point.

6. The method for dynamically correcting the state of charge according to claim 3, wherein: In response to the correction type being a static low-end correction, correcting the current available state of charge according to the correction type to obtain the corrected available state of charge includes: Acquire the rebound voltage of the battery pack when the battery pack changes from a discharge state to a static state; Adding the rebound voltage to the minimum cell voltage value in the battery pack to obtain a reference voltage; Selecting a target state of charge corresponding to the reference voltage according to a state of charge and an open circuit voltage fitting curve; In response to the target state of charge being less than a preset reference state of charge and the current available state of charge being greater than or equal to the sum of the target state of charge and an error threshold, the current available state of charge is corrected to the target state of charge.

7. The method for dynamically correcting the state of charge according to claim 3, wherein: In response to the correction type being an extreme low-end correction, correcting the current available state of charge according to the correction type to obtain the corrected available state of charge includes: The minimum single cell voltage value in the battery pack is less than the preset limit low-end correction threshold value and lasts for a first time, and the current available charge state is corrected to 0%.

8. The method for dynamically correcting the state of charge according to claim 3, wherein: In response to the correction type being an extreme high-end correction, correcting the current available state of charge according to the correction type to obtain the corrected available state of charge includes: The maximum single cell voltage value in the battery pack is less than the preset limit high-end correction threshold value and lasts for a second time, and the current available state of charge is corrected to 100%.

9. A device for dynamically correcting a state of charge, comprising: An ampere-hour integration module, configured to calculate the current available state of charge of the battery pack according to the ampere-hour integration method; A display smoothing module, configured to synchronously update the displayed state of charge to the current available state of charge; A correction module, configured to determine a correction type of the battery pack, and correct the current available state of charge according to the correction type to obtain the corrected available state of charge; In the charging state, in response to the displayed state of charge being greater than the corrected available state of charge, the display smoothing module is further configured to correct the displayed state of charge using a first correction rate for display; in response to the displayed state of charge being less than the corrected available state of charge, the display smoothing module is further configured to correct the displayed state of charge using a second correction rate for display; In the discharge state, in response to the displayed state of charge being greater than the corrected available state of charge, it is also configured to correct and display the displayed state of charge using a second correction rate; in response to the displayed state of charge being less than the corrected available state of charge, it is also configured to correct the displayed state of charge using a first correction rate; wherein the first correction rate is displayed less than the second correction rate.

10. An electronic device comprising: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the method for dynamically correcting the state of charge according to any one of claims 1-8.

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