Method and device for SOC correction of power battery

Abstract

The invention provides an SOC correction method for a power battery. The method comprises the following steps: S1, acquiring a dynamic voltage measurement value and a corresponding SOC measurement value of the power battery in a charging and discharging process; s2, an OCV-SOC reference curve of the power battery and a theoretical drift relation between the OCV-SOC reference curve and a dynamic voltage-SOC curve are obtained; s3, determining an actual drift relationship between the OCV-SOC reference curve and the dynamic voltage-SOC curve based on the dynamic voltage measurement value, the SOC measurement value and the OCV-SOC reference curve, and detecting an SOC estimation error through consistency comparison between the actual drift relationship and a theoretical drift relationship; and S4, when an SOC estimation error is detected, correcting the SOC measurement value based on the OCV-SOC reference curve. The invention further provides a device for correcting the SOC of the power battery and a computer program product.

Description

Technical Field

[0001] The present application relates to a method for correcting the SOC of a power battery. The present application also relates to a device for correcting the SOC of a power battery and a computer program product. Background Art

[0002] With the increasing popularity of electric vehicles, accurately estimating the battery's state of charge (SOC) is crucial for optimizing battery performance and improving vehicle efficiency. However, existing SOC correction methods have many limitations.

[0003] A static correction strategy based on open-circuit voltage has been proposed. However, in practical applications, the open-circuit voltage can only be accurately measured after the battery has been allowed to rest for a sufficient period of time. However, during driving, the battery is often not given sufficient rest time, resulting in a limited scope of application for this static calibration method.

[0004] In addition, SOC correction methods based on equivalent circuit models have been proposed. However, the battery's internal resistance parameter has significant temperature dependence and aging nonlinearity, making accurate online identification of internal resistance difficult. Furthermore, under dynamic driving conditions, transient changes in load can lead to a decrease in voltage and current measurement accuracy, further reducing the estimation accuracy of SOC correction methods based on traditional equivalent circuit models, making them difficult to meet the needs of practical application scenarios.

[0005] Therefore, developing a solution that can quickly and reliably correct SOC under actual usage conditions is of great significance to improving the performance of electric vehicles and user experience. Summary of the Invention

[0006] The purpose of the present application is to provide a method for correcting the SOC of a power battery, a device for correcting the SOC of a power battery, and a computer program product, so as to at least solve some of the problems in the prior art.

[0007] According to a first aspect of the present application, a method for correcting the SOC of a power battery is provided, the method comprising the following steps:

[0008] Step S1, obtaining a dynamic voltage measurement value of the power battery during the charge and discharge process, and a corresponding SOC measurement value;

[0009] Step S2, obtaining an OCV-SOC reference curve of the power battery, and a theoretical drift relationship between the OCV-SOC reference curve and a dynamic voltage-SOC curve;

[0010] Step S3, determining an actual drift relationship between the OCV-SOC reference curve and the dynamic voltage-SOC curve based on the dynamic voltage measurement value, the SOC measurement value, and the OCV-SOC reference curve, and detecting SOC estimation errors by comparing the consistency of the actual drift relationship with the theoretical drift relationship; and

[0011] Step S4: When an SOC estimation error is detected, the SOC measurement value is corrected based on the OCV-SOC reference curve.

[0012] The present application particularly includes the following technical concepts: The present application proposes a significant error remediation strategy to replace the traditional refinement strategy, thereby breaking through the reliance on the equivalent circuit model or the battery internal resistance model. The present application makes full use of the prior knowledge of the relative position relationship between the open-circuit voltage curve and the dynamic voltage curve to construct an adaptive correction mechanism based on significant deviation identification. This mechanism can accurately capture obvious SOC estimation errors during the charging and discharging process, thereby avoiding the over-correction or miscorrection problems caused by model inaccuracy in traditional methods. As a result, the robustness of SOC estimation is significantly improved, especially meeting the battery state estimation needs under complex driving conditions.

[0013] In an exemplary embodiment, in step S3: based on the comparison of the current measurement value of the power battery with a preset threshold, it is determined whether the current condition is a charging condition or a discharging condition, and a consistency comparison of the theoretical drift relationship and the actual drift relationship is performed based on the condition determination result, wherein, when the actual drift relationship is inconsistent with the theoretical drift relationship, it is determined that an SOC estimation error is detected; wherein, only when the current measurement value is greater than the first threshold for a duration exceeding a predetermined time period is it confirmed as a charging condition; only when the current measurement value is less than the second threshold for a duration exceeding a predetermined time period is it confirmed as a discharging condition, and the second threshold is less than or equal to the first threshold.

[0014] In an exemplary embodiment, the OCV-SOC reference curve includes a charging OCV-SOC reference curve and a discharging OCV-SOC reference curve, the dynamic voltage-SOC curve includes a charging dynamic voltage-SOC curve and a discharging dynamic voltage-SOC curve, and the theoretical drift relationship includes the following relationship: the charging OCV-SOC reference curve is above the charging OCV-SOC reference curve; and / or the discharging dynamic voltage-SOC curve is below the discharging OCV-SOC reference curve.

[0015] In an exemplary embodiment, step S3 includes: reading an SOC static value corresponding to a dynamic voltage measurement value on an OCV-SOC reference curve, comparing the SOC static value with the SOC measurement value, and determining whether an SOC estimation error is detected by comparing the magnitude relationship between the two; and step S4 includes: if an SOC estimation error is detected, correcting the SOC measurement value to the SOC static value.

[0016] In an exemplary embodiment, in a charging condition, if the SOC measurement value is greater than the SOC static value, then it is determined that an SOC estimation error has been detected; in a discharging condition, if the SOC measurement value is less than the SOC static value, then it is determined that an SOC estimation error has been detected.

[0017] In an exemplary embodiment, step S3 includes: reading a static voltage corresponding to an SOC measurement value on an OCV-SOC reference curve, comparing the static voltage with a dynamic voltage measurement value, and determining whether an SOC estimation error is detected by comparing the magnitude relationship between the two; and step S4 includes: if an SOC estimation error is detected, correcting the SOC measurement value to an SOC static value corresponding to the dynamic voltage measurement value on the OCV-SOC reference curve.

[0018] In an exemplary embodiment, under charging conditions, if the dynamic voltage measurement value is less than the static voltage, it is determined that an SOC estimation error has been detected; under discharging conditions, if the dynamic voltage measurement value is greater than the static voltage, it is determined that an SOC estimation error has been detected.

[0019] In an exemplary embodiment, step S2 includes: obtaining the current ambient temperature condition of the power battery, and selecting an OCV-SOC reference curve adapted thereto according to the ambient temperature condition, wherein different ambient temperature conditions correspond to different OCV-SOC reference curves.

[0020] According to a second aspect of the present application, a device for SOC correction of a power battery is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor is capable of executing the method described in the first aspect of the present application.

[0021] According to a third aspect of the present application, a computer program product is provided, comprising computer program instructions, wherein the computer program instructions, when executed by one or more processors, enable the one or more processors to perform the method according to the first aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0023] Figure 1 A flow chart showing a method for correcting the SOC of a power battery according to an exemplary embodiment of the present application is shown;

[0024] Figure 2A and Figure 2B The theoretical drift relationship between the open OCV-SOC reference curve and the dynamic voltage-SOC curve at different ambient temperatures is schematically shown respectively;

[0025] Figure 3 A schematic diagram illustrating a method for determining whether an SOC estimation error exists according to an exemplary embodiment of the present application is shown;

[0026] Figure 4 A schematic diagram illustrating a method for determining whether an SOC estimation error exists according to another exemplary embodiment of the present application; and

[0027] Figure 5 A structural block diagram of a device for correcting the SOC of a power battery according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by this application more clearly understood, this application will be further described in detail below with reference to the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit the scope of protection of this application.

[0029] Figure 1 A flow chart of a method for correcting the SOC of a power battery according to an exemplary embodiment of the present application is shown. The method includes, for example, steps S1, S2, S3, and S4.

[0030] In this article, power batteries are high-energy-density batteries that power electric vehicles and other electrically powered devices. They are typically composed of multiple battery cells (e.g., battery modules or cells). Power batteries typically utilize lithium-ion battery technology, but the methods described here are not limited to this technology and are also applicable to other battery types (e.g., lead-acid batteries) and various application scenarios (e.g., aircraft and ships).

[0031] In step S1 , a dynamic voltage measurement value of a power battery during a charge and discharge process and a corresponding SOC measurement value are obtained.

[0032] Dynamic voltage measurements refer to the change in terminal voltage over time at a battery or its contained battery cells (e.g., a battery module or cell) during the battery's charge and discharge processes. Measuring dynamic voltage typically requires a high-precision voltage sensor or data acquisition system. These devices can be included in a battery management system (BMS), for example.

[0033] The SOC measurement value refers to the state of charge measurement value of the power battery or the battery cells it contains. This can be estimated in real time, for example, using the ampere-hour integration method. The ampere-hour integration method is a SOC estimation method based on current integration. Its basic principle is to measure the current of the battery during the charge and discharge process and integrate it with time to calculate the charge and discharge amount of the battery, and then estimate the current SOC. The formula is as follows:

[0034]

[0035] Where SOC is the real-time estimated state of charge measurement value; SOC0 is the initial state of charge; C n is the rated capacity of the battery (in ampere-hours, Ah); t is the time; I(t) is the current that changes with time.

[0036] In step S2, an OCV-SOC reference curve of the power battery and a theoretical drift relationship between the OCV-SOC reference curve and a dynamic voltage-SOC curve are obtained.

[0037] In one embodiment, the current ambient temperature of the power battery can be obtained first, and an OCV-SOC reference curve adapted to the ambient temperature can be selected according to the ambient temperature. Different ambient temperature conditions correspond to different OCV-SOC reference curves.

[0038] Ambient temperature conditions can, for example, refer to different temperature intervals (for example, at intervals of 5°C, covering the range of -30°C to 60°C). Since the electrochemical characteristics of the battery change with temperature, each temperature interval corresponds to a specific OCV-SOC reference curve. For example, under low temperature conditions, the internal resistance of the battery will increase, resulting in an increase in voltage drop, while under high temperature conditions, the internal resistance of the battery will decrease and the voltage performance will also be different. Therefore, the relationship curve between the battery's OCV (open circuit voltage) and SOC (state of charge) will be different in different temperature intervals. In order to estimate the SOC more accurately, it is necessary to select the corresponding OCV-SOC reference curve according to the current temperature interval to ensure the accuracy and reliability of the SOC estimation.

[0039] For example, a database of rigorously calibrated OCV-SOC reference curves is stored locally in the vehicle or on a cloud server. This database can be organized by battery type (e.g., LFP, NCM, etc.) and ambient temperature (-30°C to 60°C, in 5°C increments). While the vehicle is in motion, the battery management system can dynamically call the optimally matched OCV-SOC reference curve based on the current battery type and ambient temperature.

[0040] In this context, the theoretical drift relationship refers to the voltage offset phenomenon caused by the polarization effect under the dynamic working state of the power battery. This offset has a clear directional characteristic.

[0041] In one embodiment, for certain battery types, battery hysteresis may not be significant, resulting in a smaller difference between the static OCV-SOC reference curves for charge and discharge. In this case, for simplicity, voltage hysteresis can be ignored, and a unified or normalized OCV-SOC reference curve is used.

[0042] During charging, due to the combined effects of electrochemical polarization and concentration polarization, the electrode potential deviates from the equilibrium potential in the positive direction, causing the charging dynamic voltage-SOC curve to be above the OCV-SOC reference curve, which satisfies the following relationship, for example:

[0043] V chg =OCV+|V ohm |+|V act |+|V conc |,

[0044] During discharge, the polarization effect causes the electrode potential to shift negatively, so that the discharge dynamic voltage-SOC curve is below the OCV-SOC reference curve, which satisfies the following relationship, for example:

[0045] V dis =OCV-|V ohm |-|V act |-|V conc |

[0046] Among them, V chg is the charging dynamic voltage, V dis is the discharge dynamic voltage, |V ohm | is ohmic polarization, |V act | is the electrochemical polarization, |V conc | is concentration polarization.

[0047] In another embodiment, the battery hysteresis effect is significant and cannot be ignored. Therefore, the OCV-SOC reference curve can be further divided into a charging OCV-SOC reference curve and a discharging OCV-SOC reference curve. The static charging curve is generally below the static discharging curve due to the energy difference between lithium ion insertion and extraction during the charging and discharging process. Therefore, the theoretical drift relationship can be updated as follows: the charging OCV-SOC reference curve is above the charging OCV-SOC reference curve; the charging OCV-SOC reference curve is above the discharging OCV-SOC reference curve; and the discharging dynamic voltage-SOC curve is below the discharging OCV-SOC reference curve.

[0048] Generally speaking, regardless of battery conditions (including current, temperature, voltage, operating state, etc.), the theoretical drift relationship between dynamic voltage (charging dynamic voltage or discharging dynamic voltage) and static OCV (open circuit voltage) always exists. This stability makes it an important basis for determining whether the SOC estimation error is excessive.

[0049] In step S3, the actual drift relationship between the OCV-SOC reference curve and the dynamic voltage-SOC curve is determined based on the dynamic voltage measurement value, the SOC measurement value and the OCV-SOC reference curve, and the SOC estimation error is detected by comparing the consistency of the actual drift relationship with the theoretical drift relationship.

[0050] In one embodiment, different theoretical drift relationships exist for charging and discharging conditions. Therefore, it is first necessary to determine whether the current operating condition is charging or discharging based on a comparison of the power battery current measurement value with a preset threshold. Subsequently, a consistency comparison between the theoretical drift relationship and the actual drift relationship is performed separately for the charging and discharging conditions.

[0051] For example, it can be specified that when the current measurement value I is greater than a first threshold (e.g., 0 A), the charging condition is determined. When the current measurement value I is less than a second threshold (e.g., 0 A), the discharging condition is determined. In addition, to eliminate measurement errors, the threshold for determining the charging condition can be set to slightly greater than zero, while the threshold for determining the discharging condition can be set to slightly less than zero.

[0052] To further enhance the reliability of operating condition determination, it can also be specified that a charging condition is only confirmed when the current measurement value I remains above a first threshold for a predetermined period of time; a discharging condition is only confirmed when the current measurement value I remains below a second threshold for a predetermined period of time, where the second threshold is less than or equal to the first threshold. For example, a timer can be used to directly measure the continuous duration of the current in a specific state. Alternatively, a counter can be used to sample and count the current state at regular intervals. When a predetermined number of samples meet the current condition, the corresponding charging or discharging condition is confirmed.

[0053] In one embodiment, if the actual drift relationship is found to be inconsistent with the theoretical drift relationship, it is determined that an SOC estimation error has been detected. Specifically, the consistency comparison can be achieved by comparing the dynamic voltage with the static voltage at the same SOC, or by comparing the SOC measurement value with the SOC static value at the same voltage. Figure 3-4 Further elaboration is not repeated here.

[0054] Specifically, the consistency comparison between the actual drift relationship and the theoretical drift relationship primarily involves checking whether the direction of the dynamic curve's shift relative to the static curve is consistent with theoretical expectations, rather than strictly pursuing the numerical accuracy of the shift. Accordingly, "SOC estimation errors" specifically refer to abnormalities that clearly violate electrochemical laws, rather than conventional minor estimation errors.

[0055] In step S4 , when an SOC estimation error is detected, the SOC measurement value is corrected based on the OCV-SOC reference curve.

[0056] In one embodiment, if an SOC estimation error is detected, the corresponding static SOC value can be found on the OCV-SOC reference curve. This value can be used as a more accurate SOC reference. Then, depending on actual needs, a direct replacement method can be used to update the abnormal SOC measurement to the static SOC value on the reference curve to achieve rapid correction. Furthermore, depending on actual needs, it is also possible to consider adding a compensation term to the static SOC value (the size of which is related to temperature and current, for example).

[0057] In particular, if no SOC estimation error is detected (i.e., the actual drift relationship matches the theoretical drift relationship), no SOC correction operation is triggered and the current SOC measurement value is retained. This ensures that corrections are only made when there is a clear error in the SOC estimation, avoiding unnecessary over-correction, thereby ensuring the stability and reliability of the SOC estimation.

[0058] In one embodiment, if an SOC estimation error is detected within N consecutive sampling periods (e.g., N=5), or if a cumulative number of non-continuous errors (e.g., M=10) occurs, it indicates a potential BMS system error or measurement device failure, and the system activates further emergency response measures. For example, this may include lighting a malfunction indicator light in the vehicle, sending a diagnostic report to the vehicle backend, or generating a fault code.

[0059] In one embodiment, if an estimation error is detected and a correction is made using the static SOC value on the reference curve, the corrected SOC value may be displayed with a label "roughly corrected value." This labeling serves to remind the user that, although the value has been corrected to avoid significant errors, it may still contain some error and not be completely accurate.

[0060] Figure 2A and Figure 2B The theoretical drift relationship between the OCV-SOC reference curve and the dynamic voltage-SOC curve at different ambient temperatures is schematically shown.

[0061] exist Figure 2A and Figure 2B In the figure, the vertical axis represents voltage, and the horizontal axis represents SOC. Four curves 101, 102, 201, and 202 are shown. The two center curves 101 and 102 represent the charge OCV-SOC reference curve and the discharge OCV-SOC reference curve, respectively. The charge curve 101 lies above the discharge curve 102, and the vertical distance between the two curves intuitively reflects the magnitude of the voltage hysteresis effect.

[0062] The top curve 201 represents the charging dynamic voltage-SOC curve, which is above the charging OCV-SOC reference curve 101. The offset between the two is caused by the charging polarization effect. The bottom curve 203 represents the discharging dynamic voltage-SOC curve, which is below the discharging OCV-SOC reference curve 102. The offset between the two is caused by the discharge polarization effect.

[0063] Figure 2A The corresponding ambient temperature is 25℃, and Figure 2B The corresponding ambient temperature is 10℃. By comparison, it is found that the ambient temperature has a certain impact on both the open circuit voltage (OCV) curve and the dynamic voltage curve. Under low temperature conditions, the chemical reaction rate slows down and the polarization effect is enhanced, so Figure 2B The OCV-SOC reference curve in Figure 2A The OCV-SOC reference curve in the figure moves downward as a whole. In addition, temperature changes will also affect the magnitude of the hysteresis effect. Figure 2B Under the low temperature conditions shown, the hysteresis effect is more significant, which is manifested in that the distance (hysteresis window) between the charging OCV-SOC reference curve 101 and the discharging OCV-SOC reference curve 102 increases.

[0064] Further observation revealed that Figure 2A Compared with the normal temperature conditions shown in Figure 2BUnder the low-temperature conditions shown, dynamic voltage curves 201 and 202 deviate significantly from the corresponding static OCV-SOC reference curves 101 and 102. This is primarily due to the more pronounced polarization effect on the battery at low temperatures, which exacerbates the deviation between the dynamic voltage and the equilibrium voltage during charge and discharge. However, regardless of temperature fluctuations, the relationship between dynamic voltage curves 201 and 202 and the OCV-SOC reference curves 101 and 102 consistently conforms to the theoretical drift law. The stability of this theoretical relationship makes it an important basis for determining whether the SOC estimation error is excessive.

[0065] It should be pointed out that Figure 2A and Figure 2B The specific positions of the dynamic voltage curves 201 and 202 and their offsets relative to the static reference curves 101 and 102 are for illustration only. As long as the theoretical drift law is satisfied, the charging dynamic voltage-SOC curve 201 may actually be located anywhere above the charging OCV-SOC reference curve 101. Similarly, the discharging dynamic voltage-SOC curve 202 may actually be located anywhere below the discharging OCV-SOC reference curve 102.

[0066] Figure 3 A schematic diagram illustrating determining whether an SOC estimation error exists according to an exemplary embodiment of the present application is shown.

[0067] Figure 3 Two sets of key curves are shown: measured charge and discharge dynamic voltage-SOC curves 201 and 202, and static OCV-SOC reference curves 101 and 102. In this embodiment, the consistency of the actual drift relationship with the theoretical drift relationship is verified by comparing the magnitude relationship between the measured SOC value and the static SOC value under the same dynamic voltage.

[0068] Under charging conditions, when the dynamic charging voltage measurement value is 3.285V, the real-time estimated SOC value read from the dynamic charging voltage-SOC curve 201 is 16.5%. The static SOC value corresponding to 3.285V read from the charging OCV-SOC reference curve 101 is 20.5%. Since 16.5% is less than 20.5%, the dynamic charging voltage-SOC curve 201 is above the charging OCV-SOC reference curve 101. This is consistent with the theoretical drift relationship and indicates that the SOC estimation is normal. Therefore, the real-time estimated SOC measurement value can continue to be used.

[0069] Under discharge conditions, when the discharge dynamic voltage measurement value is 3.235V, the real-time estimated SOC measurement value 31 read from the charge dynamic voltage-SOC curve 201 is 17.4%. The static SOC value 32 corresponding to 3.225V read from the discharge OCV-SOC reference curve 102 is 18%. Since 17.4% is less than 18%, the discharge dynamic voltage-SOC curve 202 lies above the discharge OCV-SOC reference curve 102. This is inconsistent with the theoretical drift relationship and indicates an SOC estimation error. Therefore, the abnormal SOC measurement value 31 can be corrected to the static SOC value 32, that is, 18%, to avoid excessive estimation errors.

[0070] Figure 4 A schematic diagram illustrating determining whether an SOC estimation error exists according to another exemplary embodiment of the present application is shown.

[0071] and Figure 3 Similarly, Figure 4 Two sets of key curves are also shown: measured charge and discharge dynamic voltage-SOC curves 201 and 202, and static OCV-SOC reference curves 101 and 102. In this embodiment, the consistency of the actual drift relationship with the theoretical drift relationship is verified by comparing the dynamic voltage measurement values ​​and the static voltage at the same SOC.

[0072] Under charging conditions, when the real-time estimated SOC value is 20%, the dynamic charging voltage measured from the dynamic charging voltage-SOC curve 201 is 3.305V, while the static voltage corresponding to 20% SOC, read from the OCV-SOC reference curve 101, is 3.283V. Since 3.305V is greater than 3.283V, the dynamic charging voltage-SOC curve 201 is above the OCV-SOC reference curve 101. This is consistent with the theoretical drift relationship, indicating that the SOC estimation is normal. Therefore, the real-time estimated SOC value can continue to be used.

[0073] Under discharge conditions, when the real-time estimated SOC measurement is 17.4%, the charge dynamic voltage measurement value read from the charge dynamic voltage-SOC curve 201 is 3.235V, while the static voltage corresponding to a 20% SOC read from the charge OCV-SOC reference curve 101 is 3.23V. Since 3.235V is greater than 3.23V, the discharge dynamic voltage-SOC curve 202 lies above the discharge OCV-SOC reference curve 102. This is inconsistent with the theoretical drift relationship and indicates an SOC estimation error. Therefore, the abnormal SOC measurement value 31 can be corrected to the SOC static value 32 corresponding to 3.235V (dynamic voltage measurement value) on the discharge OCV-SOC reference curve 102, that is, to 18%, to avoid excessive estimation errors.

[0074] It should be noted that although Figure 3 and Figure 4 The SOC correction process is only noted for one point (point 31) on the discharge dynamic voltage-SOC curve 202. However, as can be seen from the figure, the portion of curve 202 formed by other points near point 31 also lies above the discharge OCV-SOC reference curve 102, thus not conforming to the theoretical drift relationship. Therefore, these nearby points should also be corrected. After correction, this portion of curve 202 should overlap with the OCV-SOC reference curve 102.

[0075] Figure 5 A structural block diagram of a device for correcting the SOC of a power battery according to an exemplary embodiment of the present application is shown.

[0076] The device 500 may be implemented as a battery management system (BMS) of a vehicle or a component thereof, and in practical applications may be connected to each battery cell of a power battery of the vehicle.

[0077] like Figure 5 As shown, the device 500 includes a memory 510 and a processor 520, which may be coupled together via a bus. However, it should be understood that Figure 5 This is merely an example and does not limit the scope of this application. For example, in different application scenarios, device 500 may also include an input interface and an output interface, which is not limited herein. Optionally, device 500 may also be equipped with a communication interface to retrieve an open circuit voltage (OCV)-SOC reference curve adapted for a specific ambient temperature from a local vehicle or cloud server, if necessary.

[0078] The memory 510 stores a computer program. When the processor 520 executes the computer program, the processor 520 is capable of executing the method for correcting the SOC of a power battery according to an exemplary embodiment of the present application. This has been described in detail above and will not be repeated here for the sake of brevity. The computer program instructions may be stored in a computer-readable storage medium. The computer-readable storage medium may include, for example, a high-speed random access memory, a non-volatile memory, or a volatile solid-state memory device.

[0079] The processor 520 may be a central processing unit, or may be other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays, or other programmable logic devices.

[0080] It should be noted that the features and advantages of the method described above are also applicable to the apparatus 500 , and vice versa.

[0081] It is understood that the methods of the various embodiments of the present application can be implemented by computer programs / software. Such software can be loaded into a working memory of a processor and used to execute the methods according to the various embodiments of the present application when run.

[0082] According to another embodiment of the present application, a computer program product is provided, such as a machine (e.g., computer) readable medium, such as a CD-ROM, which includes computer program code that, when executed, causes a computer or processor to perform the methods according to various embodiments of the present application. The machine-readable medium is, for example, an optical storage medium or solid-state medium supplied with or as part of other hardware.

[0083] Although specific embodiments of the present application are described in detail herein, they are provided for illustrative purposes only and should not be considered to limit the scope of the present application. Various replacements, changes, and modifications may be conceived without departing from the spirit and scope of the present application.

Claims

1. A method for correcting the SOC of a power battery, the method comprising the following steps: Step S1, obtaining a dynamic voltage measurement value of the power battery during the charge and discharge process, and a corresponding SOC measurement value; Step S2, obtaining an OCV-SOC reference curve of the power battery, and a theoretical drift relationship between the OCV-SOC reference curve and a dynamic voltage-SOC curve; Step S3, determining an actual drift relationship between the OCV-SOC reference curve and the dynamic voltage-SOC curve based on the dynamic voltage measurement value, the SOC measurement value, and the OCV-SOC reference curve, and detecting SOC estimation errors by comparing the consistency of the actual drift relationship with the theoretical drift relationship; as well as Step S4: When an SOC estimation error is detected, the SOC measurement value is corrected based on the OCV-SOC reference curve.

2. The method according to claim 1, wherein In step S3: based on the comparison between the current measurement value of the power battery and the preset threshold value, it is determined whether the current operating condition is charging or discharging, and a consistency comparison is performed between the theoretical drift relationship and the actual drift relationship based on the operating condition determination result. When the actual drift relationship is inconsistent with the theoretical drift relationship, it is determined that an SOC estimation error has been detected; Among them, the charging condition is confirmed only when the current measurement value is greater than the first threshold for a duration exceeding a predetermined time period; the discharging condition is confirmed only when the current measurement value is less than the second threshold for a duration exceeding a predetermined time period, and the second threshold is less than or equal to the first threshold.

3. The method according to claim 1 or 2, wherein: The OCV-SOC reference curve includes a charging OCV-SOC reference curve and a discharging OCV-SOC reference curve, the dynamic voltage-SOC curve includes a charging dynamic voltage-SOC curve and a discharging dynamic voltage-SOC curve, and the theoretical drift relationship includes the following relationship: The charging OCV-SOC reference curve is above the charging OCV-SOC reference curve; and / or The discharge dynamic voltage-SOC curve is below the discharge OCV-SOC reference curve.

4. The method according to any one of claims 1 to 3, wherein Step S3 includes: reading a static SOC value corresponding to the dynamic voltage measurement value on the OCV-SOC reference curve, comparing the static SOC value with the SOC measurement value, and determining whether an SOC estimation error is detected by comparing the magnitude relationship between the two; and Step S4 includes: in the case where an SOC estimation error is detected, correcting the SOC measurement value to an SOC static value.

5. The method according to claim 4, wherein In the charging condition, if the SOC measurement value is greater than the SOC static value, it is determined that an SOC estimation error has been detected; in the discharging condition, if the SOC measurement value is less than the SOC static value, it is determined that an SOC estimation error has been detected.

6. The method according to any one of claims 1 to 5, wherein Step S3 includes: reading a static voltage corresponding to the SOC measurement value on the OCV-SOC reference curve, comparing the static voltage with the dynamic voltage measurement value, and determining whether an SOC estimation error is detected by comparing the magnitude relationship between the static voltage and the dynamic voltage measurement value; Step S4 includes: in the case where an SOC estimation error is detected, correcting the SOC measurement value to an SOC static value corresponding to the dynamic voltage measurement value on the OCV-SOC reference curve.

7. The method according to claim 6, wherein: In a charging condition, if the dynamic voltage measurement value is less than the static voltage, it is determined that an SOC estimation error is detected; in a discharging condition, if the dynamic voltage measurement value is greater than the static voltage, it is determined that an SOC estimation error is detected.

8. The method according to any one of claims 1 to 7, wherein Step S2 includes: obtaining the current ambient temperature condition of the power battery, and selecting an OCV-SOC reference curve adapted thereto according to the ambient temperature condition, wherein different ambient temperature conditions correspond to different OCV-SOC reference curves.

9. A device for correcting the SOC of a power battery, comprising a memory and a processor, wherein: The memory stores a computer program, and when the computer program is executed by the processor, the processor is capable of performing the method according to any one of claims 1 to 8.

10. A computer program product comprising computer program instructions, wherein: The computer program instructions, when executed by one or more processors, enable the one or more processors to perform the method according to any one of claims 1 to 8.

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