A SOC correction method, device, vehicle and storage medium for a power battery

Abstract

The present invention provides a method, device, vehicle and storage medium for correcting the SOC of a power battery, and belongs to the field of vehicle technology. When the vehicle is in operation, the present invention determines whether the power battery is in an undervoltage state according to the current voltage value of the power battery of the vehicle; then, when the power battery is in an undervoltage state, the current temperature, current power and current SOC value of the power battery are obtained; then, according to the above temperature and power values, a preset battery temperature-battery power-SOC relationship chart is queried to determine the corresponding target SOC value; then, according to the target SOC value, the current SOC value is corrected. According to the method of the present invention, when the vehicle is undervoltage during operation, the current operating condition parameters can be collected and the SOC value can be automatically corrected by looking up the table, thereby avoiding continuous undervoltage caused by inaccurate SOC and damaging the battery.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a SOC correction method, device, vehicle and storage medium for a power battery. Background Art

[0002] In the battery management system, the battery state of charge (SOC) is a very important battery parameter. SOC is the percentage of the remaining capacity of the battery pack to the rated capacity, which is used to measure the remaining available capacity of the battery pack. The estimation of SOC directly affects the relevant strategies of the whole vehicle and the safety of the battery. Accurate SOC can effectively improve the battery performance and battery life, and enhance the experience of the driver and passengers. In addition, SOC is also the main basis for preventing overcharging and over-discharging of power batteries.

[0003] However, during vehicle driving, since the battery is in a dynamic process, the methods for correcting the SOC are very limited, especially when discharging at high current, the SOC cannot be accurately corrected. Therefore, it is easy for the SOC to be inaccurate, leading to over-discharge and undervoltage. In the prior art, when the primary voltage of the battery is undervoltage, the SOC cannot be effectively corrected, which easily leads to deep undervoltage and damages the battery.

[0004] Therefore, in the field of vehicle technology, it is very necessary to develop a SOC correction method for a power battery to solve the problem of how to correct the SOC of the power battery in real time when undervoltage occurs during vehicle operation. Summary of the invention

[0005] In view of this, the present invention aims to propose a SOC correction method, device, vehicle and readable storage medium for a power battery to solve the problem of how to correct the SOC of a power battery in real time when undervoltage occurs during vehicle operation.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A method for correcting SOC of a power battery, the method comprising:

[0008] When the vehicle is in a running state, judging whether the power battery is in an undervoltage state according to a current voltage value of the power battery of the vehicle;

[0009] When the power battery is in an undervoltage state, obtaining a current temperature value, a current power value, and a current SOC value of the power battery;

[0010] According to the current temperature value and the current power value of the power battery, a preset battery temperature-battery power-SOC relationship chart is queried to determine the corresponding target SOC value; the relationship chart shows the mapping relationship between the SOC value and the battery temperature and the battery power;

[0011] The current SOC value is corrected according to the target SOC value.

[0012] Further, the relationship chart includes a plurality of battery power-SOC relationship curves at different temperatures, and the method of querying a preset battery temperature-battery power-SOC relationship chart according to the current temperature value and the current power value of the power battery to determine the corresponding target SOC value includes:

[0013] Determine a corresponding battery power-SOC relationship curve according to the current temperature value of the power battery; the battery power-SOC relationship curve indicates a mapping relationship between the battery power and the SOC value at the current temperature value;

[0014] According to the current power value of the power battery, a target SOC value corresponding to the battery power-SOC relationship curve is determined.

[0015] Furthermore, the battery temperature-battery power-SOC relationship diagram is obtained by simulating the discharge conditions of the power battery under actual working conditions and measuring the power values ​​of the power battery at different SOC values ​​under different temperature conditions.

[0016] Further, judging whether the power battery is in an undervoltage state according to the current voltage value of the power battery includes:

[0017] According to the cell parameter table of the power battery, obtaining the undervoltage protection value of the power battery;

[0018] Detecting the current voltage value of the power battery;

[0019] When the current voltage value is less than the undervoltage protection value, it is determined that the power battery is in an undervoltage state.

[0020] Furthermore, the detecting the current voltage value of the power battery includes:

[0021] At preset time intervals, a voltage value detected by a battery voltage sensor for the power battery is obtained.

[0022] Furthermore, the method further comprises:

[0023] When the current voltage value is not less than the undervoltage protection value, it is determined that the power battery is not in an undervoltage state, and the SOC value correction of the power battery is stopped.

[0024] Furthermore, after determining that the power battery is in an undervoltage state, the method further includes:

[0025] Send voltage fault alarm information to the driver terminal.

[0026] Furthermore, after correcting the current SOC value, the method further includes:

[0027] According to the corrected SOC value, the output power of the power battery is adjusted.

[0028] Compared with the prior art, the SOC correction method of a power battery described in the present invention has the following advantages:

[0029] 1) Accurate correction of SOC. The present invention uses a pre-calibrated SOC relationship chart (battery temperature-battery power-SOC relationship chart) to determine the current real SOC value of the battery according to the relevant parameters of the current battery (current battery temperature value and power value), thereby achieving accurate correction of SOC, making up for the shortcomings of the SOC estimation method in the prior art during vehicle driving, and improving the accuracy of calculating SOC.

[0030] 2) Avoid deep undervoltage. The present invention obtains the power and temperature of the battery after undervoltage, and according to the above parameter values, performs a table lookup to obtain the current real SOC value of the battery, and makes an accurate correction, thereby avoiding the situation where the battery continues to be undervoltage because the SOC cannot be corrected, resulting in deep undervoltage and damage to the battery.

[0031] 3) The method is simple and accurate. The present invention uses a preset battery temperature-battery power-SOC relationship chart to achieve accurate correction of SOC during vehicle driving. This method is simple and fast to operate, and fully considers the changes in SOC values ​​under different temperature conditions and different power conditions, so that the final SOC value is more accurate.

[0032] Another object of the present invention is to provide a power battery SOC correction device to solve the problem of how to correct the power battery SOC in real time when undervoltage occurs during vehicle operation. To achieve the above object, the technical solution of the present invention is implemented as follows:

[0033] A SOC correction device for a power battery, comprising:

[0034] The undervoltage determination module is configured to determine whether the power battery is in an undervoltage state according to the current voltage value of the power battery when the vehicle is in a running state;

[0035] A vehicle condition determination module is configured to, after determining that the power battery is in an undervoltage state, obtain a current temperature value, a current power value, and a current SOC value of the power battery;

[0036] A query module is configured to query a preset battery temperature-battery power-SOC relationship chart according to the current temperature value and the current power value of the power battery, and determine the corresponding target SOC value; the relationship chart shows the mapping relationship between the SOC value and the battery temperature and the battery power;

[0037] The correction module is configured to correct the current SOC value according to the target SOC value.

[0038] The advantages of the SOC correction device of the power battery and the SOC correction method of the power battery described above relative to the prior art are the same, and will not be described in detail here.

[0039] Another object of the present invention is to provide a vehicle to solve the problem of how to correct the power battery SOC in real time when undervoltage occurs during vehicle operation. To achieve the above object, the technical solution of the present invention is implemented as follows:

[0040] A vehicle, comprising:

[0041] a memory for storing instructions executable by the controller;

[0042] The controller is used to execute the SOC correction method of the power battery according to the embodiment of the present invention.

[0043] The advantages of the vehicle and the SOC correction method of the power battery described above over the prior art are the same and will not be elaborated here.

[0044] Another object of the present invention is to provide a computer-readable storage medium to solve the problem of how to correct the power battery SOC in real time when undervoltage occurs during vehicle operation. To achieve the above object, the technical solution of the present invention is implemented as follows:

[0045] A computer-readable storage medium stores computer program instructions, which are executed by a processor to implement the steps of the SOC correction method of the power battery in the embodiment of the present invention.

[0046] The advantages of the computer-readable storage medium and the SOC correction method of the power battery described above over the prior art are the same, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0048] Figure 1 A flowchart of a method for correcting the SOC of a power battery according to an embodiment of the present invention;

[0049] Figure 2 The figure is a schematic structural diagram of a SOC correction device for a power battery according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The exemplary embodiments of the present invention will be described in more detail below in conjunction with the accompanying drawings in the embodiments of the present invention. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0051] In order to facilitate understanding of the technical solution proposed by the present invention, a brief description of the relevant technology is first given here.

[0052] Overcharge or over discharge: The battery has a safe range of use, with a maximum operating voltage and a minimum operating voltage. When the actual operating voltage of the battery is lower than the minimum operating voltage or higher than the maximum operating voltage for a long time, it will cause irreversible damage to the battery, seriously damaging the battery and causing battery performance to decline. The problem of over discharge is usually that the power predicted discharge current is greater than the actual discharge capacity of the battery cell, and the failure of power prediction is usually caused by SOC estimation errors.

[0053] At present, the main method for calculating the SOC of the power battery in real time while the vehicle is driving is the ampere-hour integration algorithm. The ampere-hour integration method does not consider the internal mechanism of the battery. According to certain external characteristics of the system, such as current, time, temperature compensation, etc., the total amount of electricity flowing into and out of the battery is calculated by integrating time and current, and sometimes adding certain compensation coefficients, so as to estimate the SOC of the battery. At present, the ampere-hour integration method is widely used in battery management systems. The advantage of the ampere-hour integration method is that it is relatively less restricted by the battery's own conditions, the calculation method is simple and reliable, and the battery's SOC can be estimated in real time. The disadvantage is that since the ampere-hour measurement method belongs to open-loop detection in control, if the current acquisition accuracy is not high, the given initial SOC has a certain error. With the extension of the system operation time, the errors generated before will gradually accumulate, thereby affecting the prediction results of the SOC. And because the ampere-hour integration method only analyzes the SOC from external characteristics, there are certain errors in multiple links.

[0054] Based on the above description, the technical solution of the embodiment of the present invention is introduced as follows. Specific embodiment 1

[0056] The embodiment of the present invention provides a method for correcting the SOC of a power battery. Figure 1 is a flow chart of the steps of the method, such as Figure 1 As shown, the method includes:

[0057] Step S1: when the vehicle is in a running state, judging whether the power battery is in an undervoltage state according to the current voltage value of the power battery of the vehicle.

[0058] Undervoltage means that the voltage of the battery is lower than the minimum operating voltage. Usually, during the operation of the vehicle, due to continuous discharge, the voltage of the power battery will decrease as the SOC decreases. When a large current discharge occurs, it is easy to cause a sharp drop in voltage, lower than the minimum operating voltage, causing undervoltage. At this time, if the voltage is not restored to normal in time, it is easy for the voltage to remain low, causing more lithium ions in the negative electrode of the battery to migrate out, destroying the stable structure of the negative electrode, and causing irreversible damage to the battery. Therefore, the present invention proposes a solution for correcting the SOC when it is detected that the vehicle has an undervoltage problem during driving, so as to restore the voltage in time.

[0059] Step S2: when the power battery is in an undervoltage state, obtaining a current temperature value, a current power value and a current SOC value of the power battery.

[0060] The current temperature value refers to the temperature of the power battery cell at that moment, and the battery temperature value at the current moment can be collected by the battery temperature sensor. The current power value refers to the output power of the power battery at that moment, and the output power is mainly obtained by multiplying the current voltage and current of the battery. Since the vehicle is in the process of driving, the voltage and current are in dynamic change, and the current power value obtained is the instantaneous output power. The current SOC value refers to the SOC value displayed on the dashboard of the vehicle at that moment, and the SOC value is the current battery SOC estimated by the ampere-hour integration algorithm. Usually the battery management system controls the power output according to the SOC value.

[0061] The problem of undervoltage is usually caused by the discharge current predicted by power being greater than the actual discharge capacity of the battery cell, and the failure of power prediction is usually caused by an error in SOC estimation. Therefore, when the battery has an undervoltage problem, it usually means that the current SOC value obtained by the ampere-hour integration algorithm is not accurate enough.

[0062] Step S3: According to the current temperature value and the current power value of the power battery, query the preset battery temperature-battery power-SOC relationship chart to determine the corresponding target SOC value; the relationship chart shows the mapping relationship between the SOC value and the battery temperature and battery power.

[0063] Table 1 is an example of the battery temperature-battery power-SOC relationship chart. Specifically, as shown in Table 1, a, b, c, d, e, f, g, h, j, k, and l refer to specific numbers to represent output powers of different sizes, and in this example, a<b<c<d<e<f<g<h<j<k<1. As shown in the table header, the horizontal data represents the battery power values ​​at different SOCs at the same battery temperature; the vertical data represents the battery power values ​​at different temperatures at the same battery SOC.

[0064] Under known battery temperature conditions and a preset battery SOC value, a corresponding battery output power can be determined in the relationship chart.

[0065]

[0066] Table 1

[0067] Optionally, the battery temperature-battery power-SOC relationship diagram can be obtained by simulating discharge conditions under actual working conditions for the power battery and measuring power values ​​of the power battery at different SOC values ​​under different temperature conditions.

[0068] In this embodiment, the battery temperature-battery power-SOC relationship chart can be obtained by simulating the discharge condition of the battery and measuring the values ​​of the relevant parameters. Specifically, the battery temperature and SOC can be controlled to discharge the battery at a certain power under different battery temperatures and battery SOC values. The minimum power value at which the battery can reduce the voltage to the undervoltage protection value within 10 seconds is the maximum output power of the battery at the battery temperature and SOC. The maximum output power is the output power corresponding to the battery at the temperature and SOC. According to the above method, the output power of the battery under different temperature and SOC value conditions is measured, and the corresponding relationship and values ​​of multiple groups of temperature, power, and SOC parameters are recorded, so as to draw a battery temperature-battery power-SOC relationship chart. In practical applications, the relationship chart is stored in the battery management system. When an undervoltage problem is detected in the battery, the current temperature and power values ​​of the battery are measured, and the above values ​​can be directly brought into the relationship chart, and the corresponding target SOC value can be obtained by reverse query. The target SOC value refers to the actual SOC value of the power battery under the current working conditions. In this way, an accurate SOC value can be obtained simply and quickly by looking up the table, while taking into account the influence of the current temperature and power on the SOC, and also solving the errors that are easy to occur when estimating the SOC using the ampere-hour integration algorithm.

[0069] Step S4: Correcting the current SOC value according to the target SOC value.

[0070] The target SOC value is the actual SOC value of the power battery under the current working condition obtained by looking up the table. The current SOC value refers to the SOC value displayed on the vehicle's dashboard at that moment, which is the value estimated by the battery management system through the ampere-hour integration algorithm. Correcting the SOC value means correcting the current SOC value to the target SOC value and displaying it on the vehicle's dashboard.

[0071] Therefore, through the SOC correction method provided by the embodiment of the present invention, when it is determined that the vehicle has an undervoltage problem during operation, the actual SOC under the current working condition can be quickly obtained by collecting the current battery temperature and power values ​​and looking up the table to automatically correct the SOC value. This method is simple, fast, and accurate. In addition, it can also avoid continuous undervoltage caused by inaccurate SOC and damage to the battery.

[0072] Optionally, step S1 includes the following steps:

[0073] Step S11: acquiring an undervoltage protection value of the power battery according to a cell parameter table of the power battery.

[0074] Step S12: Detect the current voltage value of the power battery.

[0075] Step S13: when the current voltage value is less than the undervoltage protection value, it is determined that the power battery is in an undervoltage state.

[0076] The undervoltage protection value refers to the minimum operating voltage of the power battery, and the parameters of the undervoltage protection value can usually be obtained from the battery cell parameter table. By real-time detection of the current voltage value of the battery, when it is determined that the current voltage value of the power battery is lower than the undervoltage protection value, it means that the current battery has an undervoltage problem.

[0077] In one embodiment, step S12 includes:

[0078] At preset time intervals, a voltage value detected by a battery voltage sensor for the power battery is obtained.

[0079] During the driving process of the vehicle, the voltage of the power battery is detected in real time by the battery voltage sensor. Specifically, it can be detected once every preset time to determine whether there is an undervoltage problem. For example, the voltage can be detected once every 5 seconds, once every 30 seconds, or once every 60 seconds, and there is no limitation on it. In this embodiment, the battery voltage is detected once every preset time, so that the battery undervoltage problem can be discovered in time, avoiding the continuous low discharge of the battery.

[0080] Optionally, the method further comprises:

[0081] When the current voltage value is not less than the undervoltage protection value, it is determined that the power battery is not in an undervoltage state, and the SOC value correction of the power battery is stopped.

[0082] When the battery voltage collected in step S1 is not lower than the undervoltage protection value, it is considered that the current battery does not have an undervoltage problem, the current SOC value is still accurate, and there is no need to correct it. The subsequent steps can be omitted, that is, the SOC value correction of the power battery is stopped, thereby reducing unnecessary calculation processes.

[0083] Optionally, after determining that the power battery is in an undervoltage state, the method further includes:

[0084] Send voltage fault alarm information to the driver terminal.

[0085] When it is determined that the power battery has an undervoltage problem, a voltage fault alarm can be sent to the driver's terminal or the vehicle's display dashboard. The driver can stop the vehicle for relevant maintenance operations or reduce the vehicle speed and limit its operating power according to the alarm information.

[0086] In one embodiment, the relationship chart includes a plurality of battery power-SOC relationship curves at different temperatures, and the method of querying a preset battery temperature-battery power-SOC relationship chart according to the current temperature value and the current power value of the power battery to determine the corresponding target SOC value includes:

[0087] According to the current temperature value of the power battery, the corresponding battery power-SOC relationship curve is determined; the battery power-SOC relationship curve shows the mapping relationship between battery power and SOC value under the current temperature value; according to the current power value of the power battery, the corresponding target SOC value on the battery power-SOC relationship curve is determined.

[0088] When the vehicle is driving, the voltage and current of the power battery will be in dynamic change. This embodiment takes into account that the SOC value of the power battery is not only related to the temperature, but also affected by the current and voltage changes during driving. Therefore, by controlling variables, multiple groups of tests are performed to obtain the relationship curve between SOC and battery power under different temperature conditions. This embodiment takes into account multiple factors affecting the battery SOC, and then obtains data by controlling variables for multiple tests, so that the SOC value obtained using the relationship chart is more accurate and true.

[0089] Optionally, after correcting the current SOC value, the method further includes:

[0090] According to the corrected SOC value, the output power of the power battery is adjusted.

[0091] The power prediction module in the battery management system can adjust the output power of the power battery according to the corrected SOC value. Specifically, the battery has an undervoltage problem mainly because the SOC before correction is higher than the actual SOC value of the battery, resulting in too high output power. After correcting the battery SOC, the power prediction module in the battery management system can reduce the output power of the battery accordingly after detecting that the SOC has decreased. The reduction in power reduces the current flowing through the battery, which further reduces the voltage division of the battery. Since the terminal voltage of the battery is equal to the static voltage of the battery minus the voltage division, when the voltage division becomes smaller, the terminal voltage of the battery will increase appropriately, thereby returning to a normal state, avoiding the problem of deep undervoltage and damage to the battery when the voltage cannot be restored due to undervoltage problems.

[0092] The embodiment of the present invention determines whether the power battery is in an undervoltage state according to the current voltage value of the power battery of the vehicle when the vehicle is in operation; when the power battery is in an undervoltage state, the current temperature, current power and current SOC value of the power battery are obtained; then, according to the current temperature value and the current power value, the preset battery temperature-battery power-SOC relationship chart is queried to determine the corresponding target SOC value; then, according to the target SOC value, the current SOC value is corrected; finally, according to the corrected SOC value, the output power value of the power battery is adjusted. Therefore, when the vehicle is undervoltage during operation, the SOC value can be automatically corrected by looking up the table, thereby adjusting the output power of the power battery, so that the voltage returns to normal, avoiding continuous undervoltage and damage to the battery. Specific embodiment 2

[0094] Based on the same inventive concept, an embodiment of the present invention further provides a SOC correction device for a power battery. Figure 2 is a structural schematic diagram of the device, such as Figure 2 As shown, the device comprises:

[0095] The undervoltage determination module is configured to determine whether the power battery is in an undervoltage state according to the current voltage value of the power battery when the vehicle is in a running state;

[0096] A vehicle condition determination module is configured to, after determining that the power battery is in an undervoltage state, obtain a current temperature value, a current power value, and a current SOC value of the power battery;

[0097] A query module is configured to query a preset battery temperature-battery power-SOC relationship chart according to the current temperature value and the current power value of the power battery, and determine the corresponding target SOC value; the relationship chart shows the mapping relationship between the SOC value and the battery temperature and the battery power;

[0098] The correction module is configured to correct the current SOC value according to the target SOC value.

[0099] Optionally, the relationship chart includes a plurality of battery power-SOC relationship curves at different temperatures, and the query module includes:

[0100] A first query submodule is used to determine a corresponding battery power-SOC relationship curve according to the current temperature value of the power battery; the battery power-SOC relationship curve indicates a mapping relationship between the battery power and the SOC value at the current temperature value;

[0101] The second query submodule is used to determine the target SOC value corresponding to the battery power-SOC relationship curve according to the current power value of the power battery.

[0102] Optionally, the undervoltage determination module includes:

[0103] A first determination submodule, configured to obtain an undervoltage protection value of the power battery according to a cell parameter table of the power battery;

[0104] A second determination submodule, used to detect a current voltage value of the power battery;

[0105] The third determination submodule is used to determine that the power battery is in an undervoltage state when the current voltage value is less than the undervoltage protection value.

[0106] Optionally, the second determining submodule includes:

[0107] The detection submodule is used to obtain the voltage value detected by the battery voltage sensor for the power battery at preset time intervals.

[0108] Optionally, the undervoltage determination module further includes:

[0109] The stop submodule is used to determine that the power battery is not in an undervoltage state when the current voltage value is not less than the undervoltage protection value, and then stop correcting the SOC value of the power battery.

[0110] Optionally, the device further comprises:

[0111] The alarm module is used to send voltage fault alarm information to the driver terminal.

[0112] Optionally, the device further comprises:

[0113] The regulating module is used to regulate the output power of the power battery according to the corrected SOC value. Specific embodiment three

[0115] Based on the same inventive concept, an embodiment of the present invention further provides a vehicle, comprising:

[0116] a memory for storing instructions executable by the controller;

[0117] The controller is used to execute a SOC correction method of a power battery provided in an embodiment of the present invention. Specific embodiment 4

[0119] Based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium having computer program instructions stored thereon, and the program instructions are executed by a processor to implement the steps of a power battery SOC correction method provided in an embodiment of the present invention.

[0120] The present invention provides a method, device, vehicle and storage medium for correcting the SOC of a power battery, and belongs to the field of vehicle technology. The present invention first determines whether the power battery is in an undervoltage state according to the current voltage value of the power battery of the vehicle when the vehicle is in a running state; then, when the power battery is in an undervoltage state, the current temperature, current power and current SOC value of the power battery are obtained; then, according to the above temperature and power values, a preset battery temperature-battery power-SOC relationship chart is queried to determine the corresponding target SOC value; finally, according to the target SOC value, the current SOC value is corrected. The method of the present invention, when the vehicle is undervoltage during operation, can automatically correct the SOC value by collecting the current operating condition parameters and looking up the table, thereby avoiding continuous undervoltage caused by inaccurate SOC and damaging the battery.

[0121] For the method embodiments, for the sake of simplicity, they are all described as a series of operation combinations, but those skilled in the art should know that the present invention is not limited by the described operation sequence, because according to the present invention, some steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the operations and experimental conditions involved are not necessarily required by the present invention.

[0122] The SOC correction method, device, vehicle and storage medium of a power battery provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for correcting the SOC of a power battery, characterized in that: The method comprises: When the vehicle is in a running state, judging whether the power battery is in an undervoltage state according to the current voltage value of the power battery of the vehicle; the undervoltage state refers to a state in which the current voltage value of the power battery is lower than the minimum operating voltage; When the power battery is in an undervoltage state, obtaining a current temperature value, a current power value, and a current SOC value of the power battery; According to the current temperature value and the current power value of the power battery, a preset battery temperature-battery power-SOC relationship chart is queried to determine the corresponding target SOC value; the relationship chart shows the mapping relationship between the SOC value and the battery temperature and the battery power; the battery power in the relationship chart represents the minimum power value of the power battery to reduce the voltage to the undervoltage protection value within 10 seconds under the corresponding battery temperature and SOC value; The current SOC value is corrected according to the target SOC value.

2. The method according to claim 1, characterized in that: The relationship chart includes a plurality of battery power-SOC relationship curves at different temperatures, and the preset battery temperature-battery power-SOC relationship chart is queried according to the current temperature value and the current power value of the power battery to determine the corresponding target SOC value, including: Determine a corresponding battery power-SOC relationship curve according to the current temperature value of the power battery; the battery power-SOC relationship curve indicates a mapping relationship between the battery power and the SOC value at the current temperature value; According to the current power value of the power battery, a target SOC value corresponding to the battery power-SOC relationship curve is determined.

3. The method according to claim 1, characterized in that: The battery temperature-battery power-SOC relationship diagram is obtained by simulating the discharge conditions of the power battery under actual working conditions and measuring the power values ​​of the power battery at different SOC values ​​under different temperature conditions.

4. The method according to claim 1, characterized in that: The determining, according to the current voltage value of the power battery, whether the power battery is in an undervoltage state comprises: According to the cell parameter table of the power battery, obtaining the undervoltage protection value of the power battery; Detecting the current voltage value of the power battery; When the current voltage value is less than the undervoltage protection value, it is determined that the power battery is in an undervoltage state.

5. The method according to claim 4, characterized in that: The detecting the current voltage value of the power battery includes: At preset time intervals, a voltage value detected by a battery voltage sensor for the power battery is obtained.

6. The method according to claim 4, characterized in that: The method further comprises: When the current voltage value is not less than the undervoltage protection value, it is determined that the power battery is not in an undervoltage state, and the SOC value correction of the power battery is stopped.

7. The method according to any one of claims 1 to 6, characterized in that: After determining that the power battery is in an undervoltage state, the method further includes: Send voltage fault alarm information to the driver terminal.

8. The method according to any one of claims 1 to 6, characterized in that: After correcting the current SOC value, the method further includes: According to the corrected SOC value, the output power of the power battery is adjusted.

9. A SOC correction device for a power battery, characterized in that: include: The undervoltage determination module is configured to determine whether the power battery is in an undervoltage state according to the current voltage value of the power battery when the vehicle is in a running state; The undervoltage state refers to a state where the current voltage value of the power battery is lower than the minimum operating voltage; A vehicle condition determination module is configured to, after determining that the power battery is in an undervoltage state, obtain a current temperature value, a current power value, and a current SOC value of the power battery; A query module is configured to query a preset battery temperature-battery power-SOC relationship chart according to a current temperature value and a current power value of the power battery, and determine a corresponding target SOC value; The relationship chart shows the mapping relationship between the SOC value and the battery temperature and battery power; the battery power in the relationship chart represents the minimum power value of the power battery to reduce the voltage to the undervoltage protection value within 10 seconds under the corresponding battery temperature and SOC value; The correction module is configured to correct the current SOC value according to the target SOC value.

10. A vehicle, characterized in that: The vehicle comprises: a memory for storing instructions executable by the controller; A controller for executing the method according to any one of claims 1 to 8.

11. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: The program instructions are executed by a processor to implement the steps of the method according to any one of claims 1 to 8.

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