CN115267560A

CN115267560A - SOC correction method and device for power battery, vehicle and storage medium

Info

Publication number: CN115267560A
Application number: CN202210391537.XA
Authority: CN
Inventors: 康文蓉; 何佳昕
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-11-01

Abstract

The invention provides a method and a device for correcting SOC of a power battery, a vehicle and a storage medium, and belongs to the technical field of vehicles. When the vehicle is in the running state, whether the power battery is in the undervoltage state or not is judged according to the current voltage value of the power battery of the vehicle; then, under the condition that the power battery is in an undervoltage state, acquiring the current temperature, the current power and the current SOC value of the power battery; then, according to the temperature and the power value, inquiring a preset battery temperature-battery power-SOC relation chart, and determining a corresponding target SOC value; and then, correcting the current SOC value according to the target SOC value. According to the method, when the vehicle is under-voltage in the running process, the SOC value can be automatically corrected by acquiring the current working condition parameters and looking up the table, so that the problem that the battery is damaged due to continuous under-voltage caused by inaccurate SOC is avoided.

Description

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

Technical Field

The invention relates to the technical field of vehicles, in particular to a method and a device for correcting SOC of a power battery, a vehicle and a storage medium.

Background

In battery management systems, battery state of charge (SOC) is a very important battery parameter. The SOC is a percentage value of the remaining capacity of the battery pack to the rated capacity, and is used for measuring the currently remaining available capacity of the battery pack. The estimation of the SOC directly influences relevant strategies of the whole vehicle and the safety of the battery, the accurate SOC can effectively improve the performance of the battery and the service life of the battery, and the experience of drivers and passengers is improved. In addition, SOC is the main basis for preventing overcharge and overdischarge of the power battery.

However, since the battery is in a dynamic state during the driving of the vehicle, the SOC cannot be corrected accurately, particularly when a large current is discharged. Therefore, the SOC is prone to be inaccurate, resulting in over-discharge and under-voltage. In the prior art, when the primary undervoltage of the battery, the SOC cannot be effectively corrected, so that the deep undervoltage is easily caused, and the battery is further damaged.

Therefore, in the technical field of vehicles, it is necessary to develop a method for correcting the SOC of a power battery to solve the problem of how to correct the SOC of the power battery in real time when the vehicle is under-voltage during operation.

Disclosure of Invention

In view of this, the present invention aims to provide a method and an apparatus for correcting SOC of a power battery, a vehicle and a readable storage medium, so as to solve the problem of how to correct the SOC of the power battery in real time when undervoltage occurs during the vehicle operation.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method for correcting SOC of a power battery, the method comprising:

when a vehicle is in a running state, judging whether a power battery of the vehicle is in an undervoltage state or not according to the current voltage value of the power battery;

under the condition that the power battery is in an undervoltage state, acquiring a current temperature value, a current power value and a current SOC value of the power battery;

inquiring a preset battery temperature-battery power-SOC relation chart according to the current temperature value and the current power value of the power battery, and determining a corresponding target SOC value; the relation chart shows a mapping relation between the SOC value and the battery temperature and the battery power;

and correcting the current SOC value according to the target SOC value.

Further, the relationship chart includes a plurality of battery power-SOC relationship curves at different temperatures, and the step 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 a corresponding target SOC value includes:

determining a corresponding battery power-SOC relation curve according to the current temperature value of the power battery; the battery power-SOC relation curve shows a mapping relation between the battery power and the SOC value under the current temperature value;

and determining a corresponding target SOC value on the battery power-SOC relation curve according to the current power value of the power battery.

Further, the battery temperature-battery power-SOC relation chart is obtained by respectively measuring power values of the power battery at different SOC values under different temperature conditions by simulating discharge conditions of the power battery under actual conditions, and then drawing the power value.

Further, the determining whether the power battery is in an undervoltage state according to the current voltage value of the power battery includes:

acquiring an undervoltage protection value of the power battery according to the battery core parameter table of the power battery;

detecting the current voltage value of the power battery;

and when the current voltage value is smaller than the undervoltage protection value, judging that the power battery is in an undervoltage state.

Further, the detecting the current voltage value of the power battery includes:

and acquiring the voltage value detected by the battery voltage sensor aiming at the power battery at preset time intervals.

Further, the method further comprises:

and when the current voltage value is not less than the under-voltage protection value, judging that the power battery is not in an under-voltage state, and stopping correcting the SOC value of the power battery.

Further, after determining that the power battery is in an under-voltage state, the method further includes:

and sending voltage fault alarm information to a driver terminal.

Further, after the current SOC value is corrected, the method further includes:

and adjusting the output power of the power battery according to the corrected SOC value.

Compared with the prior art, the SOC correction method of the power battery has the following advantages:

1) And accurate correction of the SOC is realized. The invention utilizes the pre-calibrated SOC relation chart (battery temperature-battery power-SOC relation chart) to determine the current real SOC value of the battery according to the related parameters (the current temperature value and the current power value of the battery) of the current battery, thereby realizing the accurate correction of the SOC, making up the defects of the SOC estimation method in the vehicle driving process in the prior art and improving the accuracy of calculating the SOC.

2) Deep under-voltage is avoided. According to the invention, after undervoltage, the power and the temperature of the battery are acquired, the current real SOC value of the battery is obtained by table lookup according to the parameter values, and accurate correction is carried out, so that the problem that the battery is damaged due to deep undervoltage caused by continuous undervoltage of the battery because the SOC cannot be corrected is avoided.

3) The method is simple and accurate. The invention realizes the accurate correction of the SOC in the driving process of the vehicle by utilizing the preset relation chart of the battery temperature, the battery power and the SOC. The method is simple and rapid to operate, and fully considers the change of the SOC values under different temperature conditions and different power conditions, so that the finally obtained SOC value is more accurate.

The invention also aims to provide a device for correcting the SOC of the power battery, so as to solve the problem of how to correct the SOC of the power battery in real time when undervoltage occurs during the running process of a vehicle. In order to achieve the purpose, the technical scheme of the invention is realized as follows:

an SOC correction device of a power battery comprises:

the undervoltage determining module is configured to judge whether the power battery is in an undervoltage state or not according to the voltage value of the current power battery when the vehicle is in a running state;

the vehicle condition determining module is configured to obtain a current temperature value, a current power value and a current SOC value of the power battery after determining that the power battery is in an under-voltage state;

the query module is configured to query a preset battery temperature-battery power-SOC relation chart according to the current temperature value and the current power value of the power battery and determine a corresponding target SOC value; the relation chart shows a mapping relation between the SOC value and the battery temperature and the battery power;

and the correction module is configured to correct the current SOC value according to the target SOC value.

Compared with the prior art, the SOC correction device of the power battery and the SOC correction method of the power battery have the same advantages, and are not repeated herein.

The invention also aims to provide a vehicle to solve the problem of how to correct the SOC of the power battery in real time when undervoltage occurs in the running process of the vehicle. In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a vehicle, the vehicle comprising:

a memory for storing controller executable instructions;

and the controller is used for executing the SOC correction method of the power battery.

Compared with the prior art, the vehicle and the SOC correction method of the power battery have the same advantages, and are not repeated herein.

Another objective 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 the vehicle is under-voltage during operation. In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a computer-readable storage medium having stored thereon computer program instructions, which are executed by a processor, to implement the steps of the above-described SOC correction method of the power battery of the embodiment of the present invention.

The advantages of the computer readable storage medium and the SOC correction method of the power battery are the same as those of the prior art, and are not described herein again.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a flowchart illustrating steps of a method for correcting SOC of a power battery according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an SOC correction device for a power battery according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in which embodiments of the invention are shown. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In order to facilitate understanding of the technical solutions proposed by the present invention, a brief description of related technologies is provided herein.

Overcharge or overdischarge: the battery has a safe use interval, has the highest working voltage and the lowest working voltage, and when the actual working voltage of the battery is lower than the lowest working voltage or higher than the highest working voltage for a long time, the battery can be damaged irreversibly, the battery is seriously damaged, and the performance of the battery is reduced. The problem of over-discharge is that the discharge current of power prediction is larger than the actual discharge capacity of the battery cell, and the failure of power prediction is caused by the error of SOC estimation.

At present, a method for calculating the SOC of a power battery in real time during the running process of a vehicle is mainly an ampere-hour integration algorithm. The ampere-hour integration method does not consider the action mechanism in the battery, and calculates the total electric quantity flowing into and out of the battery by integrating time and current according to certain external characteristics of the system, such as current, time, temperature compensation and the like, and sometimes adding certain compensation coefficients, so as to estimate the SOC of the battery. At present, an ampere-hour integration method is widely applied to a battery management system. The ampere-hour integration method has the advantages that the limitation of the battery is relatively small, the calculation method is simple and reliable, and the SOC of the battery can be estimated in real time. The method has the disadvantages that the ampere-hour metering method belongs to open-loop detection in control, if the current acquisition precision is not high, a given initial SOC has a certain error, and the error generated before is gradually accumulated along with the extension of the system running time, so that the prediction result of the SOC is influenced. And because the ampere-hour integration method is only used for analyzing the SOC from external characteristics, a certain error exists in multiple links.

Based on the above description, the technical solutions of the embodiments of the present invention are described as follows.

Detailed description of the preferred embodiment

The embodiment of the invention provides a method for correcting the SOC of a power battery, and fig. 1 is a flow chart of the steps of the method, and as shown in fig. 1, the method comprises the following steps:

step S1: when the vehicle is in a running state, judging whether the power battery is in an undervoltage state or not according to the current voltage value of the power battery of the vehicle.

Undervoltage means that the voltage of the battery is below the lowest operating voltage. In general, during running of the vehicle, the voltage of the power battery decreases as the SOC decreases due to continuous discharge. When large-current discharge occurs, the voltage is easily reduced sharply and is lower than the lowest working voltage, so that undervoltage is caused. If the voltage is not timely restored to be normal, the voltage is easy to continuously lower, more lithium ions in the negative electrode of the battery are migrated out, the stable structure of the negative electrode is damaged, and the battery is irreversibly damaged. Therefore, the invention provides a scheme for correcting the SOC when detecting that the vehicle has an undervoltage problem in the driving process so as to recover the voltage in time.

Step S2: and under the condition that the power battery is in an undervoltage state, acquiring the current temperature value, the current power value and the current SOC value of the power battery.

The current temperature value refers to the temperature of the single power battery at the moment, and the temperature of the battery at the current moment can be acquired through a temperature sensor of the battery. The current power value refers to the output power of the power battery at the moment, and the output power is mainly obtained by the product of the current voltage and the current of the battery. Since the voltage and the current are in dynamic changes during the running process of the vehicle, the obtained current power value is the instantaneous output power. The current SOC value is an SOC value displayed on an instrument panel of the vehicle at that time, and the SOC value is the current battery SOC estimated by the ampere-hour integration algorithm. The battery management system normally performs power output control in accordance with the SOC value.

The problem of the undervoltage is generally caused by the fact that the discharge current of the power prediction is larger than the actual discharge capacity of the battery cell, and the failure of the power prediction is generally caused by the error of the 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.

And step S3: inquiring a preset battery temperature-battery power-SOC relation chart according to the current temperature value and the current power value of the power battery, and determining a corresponding target SOC value; the map indicates a mapping relationship between the SOC value and the battery temperature and the battery power.

Table 1 is an example of the battery temperature-battery power-SOC relation table, specifically, as shown in table 1, wherein a, b, c, d, e, f, g, h, j, k, l denote specific numbers to represent output powers of different magnitudes, and in this example, a < b < c < d < e < f < g < h < j < k < 1. According to the table header, the transverse data represent the battery power values at different SOC under the same battery temperature; the vertical data represents the battery power values at different temperatures under the same battery SOC.

Under known battery temperature conditions, and preset battery SOC values, a corresponding battery output power may be determined in the relationship chart.

T\SOC

≤2％

3％

4％

5％

10％

15％

20％

25％

30％

35％

40％

45％

50％

55％

60％

65％

70％

75％

80％

85％

90％

95％

≥100％

＜-30℃

a

-30℃

a

b

c

d

e

-25℃

a

b

c

d

e

-20℃

a

b

c

d

e

f

-15℃

a

b

c

d

e

f

g

-10℃

a

b

c

d

e

f

g

-5℃

a

b

c

d

e

f

g

0℃

a

b

c

d

e

f

g

h

5℃

a

b

c

d

e

f

g

h

10℃

a

b

c

d

e

f

h

j

15℃

a

b

c

e

f

g

h

j

20℃

a

c

e

g

h

j

k

25℃

a

c

e

g

h

j

k

l

30℃

a

c

e

g

h

j

k

l

35℃

a

c

e

g

h

j

k

l

40℃

a

c

e

g

h

j

k

l

45℃

a

c

e

g

h

j

k

l

50℃

a

c

d

g

h

j

51℃

a

c

d

e

f

52℃

a

b

d

e

55℃

a

b

d

e

＞55℃

a

TABLE 1

Optionally, the battery temperature-battery power-SOC relation graph may be obtained by plotting power values of the power battery at different SOC values under different temperature conditions by simulating discharge conditions of the power battery under actual conditions.

In this embodiment, the battery temperature-battery power-SOC relation chart may be obtained by simulating a discharge condition of the battery, measuring the relevant parameter values, and performing a sorting process. Specifically, the temperature and the SOC of the battery can be controlled, the battery is enabled to work and discharge according to a certain power under the conditions of different battery temperatures and battery SOC values, the minimum power value of the battery, which can reduce the voltage to the under-voltage protection value within 10s, is the maximum output power of the battery under the battery temperatures and the SOC, and the maximum output power is the corresponding output power of the battery under the conditions of the temperatures and the SOC. According to the method, the output power of the battery under different temperature and SOC values is measured, and the corresponding relation and the values of a plurality of groups of temperature, power and SOC parameters are recorded, so that a battery temperature-battery power-SOC relation chart is drawn. In practical application, the relation chart is stored in a battery management system, when the problem of undervoltage of the battery is detected, the current temperature value and the current power value of the battery are measured, the values can be directly brought into the relation chart, a corresponding target SOC value is obtained through reverse checking, the target SOC value refers to the real SOC value of the power battery under the current working condition, therefore, the accurate SOC value can be simply and quickly obtained through table checking, meanwhile, the influence of the current temperature and power on the SOC is considered, and errors easily generated when the SOC is estimated by adopting an ampere-hour integration algorithm are solved.

And step S4: and correcting the current SOC value according to the target SOC value.

And the target SOC value is the real SOC value of the power battery under the current working condition obtained by looking up the table. And the current SOC value refers to the SOC value displayed on an instrument panel of the vehicle at the moment, and the value is estimated by the battery management system through an ampere-hour integration algorithm. Correcting the SOC value means that the current SOC value is corrected to a target SOC value and displayed on an instrument panel of the vehicle.

Therefore, by the SOC correction method provided by the embodiment of the invention, when the vehicle is judged to have the undervoltage problem in the running process, the real SOC under the current working condition can be quickly obtained by acquiring the current temperature and power values of the battery and looking up the table so as to automatically correct the SOC value. Besides, continuous undervoltage caused by inaccurate SOC can be avoided, and the battery is prevented from being damaged.

Optionally, step S1 comprises the steps of:

step S11: and acquiring the undervoltage protection value of the power battery according to the battery core parameter table of the power battery.

Step S12: and detecting the current voltage value of the power battery.

Step S13: and when the current voltage value is smaller than the undervoltage protection value, judging that the power battery is in an undervoltage state.

The undervoltage protection value refers to the lowest working voltage of the power battery, and the parameter of the undervoltage protection value can be obtained on a battery core parameter table of the battery generally. By detecting the current voltage value of the battery in real time, when the current voltage value of the power battery is judged to be lower than the undervoltage protection value, the undervoltage problem of the current battery is indicated.

In one embodiment, step S12 includes:

In the running process of the vehicle, the voltage of the power battery is detected in real time through the battery voltage inductor, specifically, the voltage is detected once every preset time, and whether the undervoltage problem occurs or not is judged. For example, the voltage may be detected every 5S, every 30S, and every 60S, which is not limited herein. In the embodiment, the battery voltage is detected once every preset time, so that the problem of battery under-voltage can be found in time, and continuous low discharge of the battery is avoided.

Optionally, the method further comprises:

When the battery voltage collected in the step S1 is not lower than the undervoltage protection value, the current battery is not considered to have undervoltage problem, the current SOC value is still accurate, and the correction is not necessary, so that the SOC value correction of the power battery can be stopped without performing the subsequent steps, and the unnecessary calculation process is reduced.

Optionally, after determining that the power battery is in an under-voltage state, the method further includes:

and sending voltage fault alarm information to a driver terminal.

When the power battery is judged to have the undervoltage problem, a voltage fault alarm can be sent to a terminal of a driver or a display instrument panel of a vehicle. The driver can stop the vehicle according to the alarm information to carry out relevant maintenance operation, or reduce the speed of the vehicle and limit the running power of the vehicle.

In one embodiment, the step of determining the target SOC value includes the steps of:

determining a corresponding battery power-SOC relation curve according to the current temperature value of the power battery; the battery power-SOC relation curve indicates a mapping relation between the battery power and the SOC value under the current temperature value; and determining a corresponding target SOC value on the battery power-SOC relation curve according to the current power value of the power battery.

When a vehicle runs, the voltage and the current of the power battery are always in dynamic change, and the embodiment considers that the SOC value of the power battery is not only related to the temperature, but also influenced by the current and the voltage change in the running process, so that the relation curves of the SOC and the battery power under different temperature conditions are obtained through multiple groups of tests by controlling variables. According to the embodiment, a plurality of influence factors on the SOC of the battery are considered, and data are obtained through multiple tests of the control variables, so that the SOC value obtained by using the relation chart is more accurate and real.

Optionally, after the current SOC value is corrected, the method further includes:

And a 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 problem of undervoltage of the battery occurs mainly because the SOC before correction is higher than the actual SOC value of the battery, which results in excessively high output power. After correcting the SOC of the battery, the power prediction module in the battery management system may reduce the output power of the battery accordingly after detecting the SOC reduction. The reduction in power causes the current flowing through the battery to be small, thereby further causing the partial pressure of the battery to be small. The terminal voltage of the battery is equal to the static voltage of the battery minus the divided voltage, so that when the divided voltage is reduced, the terminal voltage of the battery is properly increased, and the battery is recovered to a normal state, and the problem that the battery is damaged because the voltage cannot be recovered all the time and deep undervoltage is generated when the undervoltage problem occurs is solved.

According to the embodiment of the invention, when the vehicle is in the running state, whether the power battery is in the undervoltage state or not is judged according to the current voltage value of the power battery of the vehicle; under the condition that the power battery is in an undervoltage state, acquiring the current temperature, the current power and the current SOC value of the power battery; then, according to the current temperature value and the current power value, inquiring a preset battery temperature-battery power-SOC relation chart, and determining a corresponding target SOC value; then, correcting the current SOC value according to the target SOC value; and finally, adjusting the output power value of the power battery according to the corrected SOC value. Therefore, when the vehicle is under-voltage in the running process, the SOC value can be automatically corrected through table lookup, so that the output power of the power battery is adjusted, the voltage returns to be normal, and the battery is prevented from being damaged due to continuous under-voltage.

Detailed description of the invention

Based on the same inventive concept, an embodiment of the present invention further provides an SOC correction apparatus for a power battery, fig. 2 is a schematic structural diagram of the apparatus, and as shown in fig. 2, the apparatus includes:

Optionally, the relation table includes a plurality of battery power-SOC relation curves at different temperatures, and the query module includes:

the first query submodule is used for determining a corresponding battery power-SOC relation curve according to the current temperature value of the power battery; the battery power-SOC relation curve shows a mapping relation between the battery power and the SOC value under the current temperature value;

and the second query submodule is used for determining a corresponding target SOC value on the battery power-SOC relation curve according to the current power value of the power battery.

Optionally, the under-voltage determination module includes:

the first determining submodule is used for acquiring an undervoltage protection value of the power battery according to a battery core parameter table of the power battery;

the second determining submodule is used for detecting the current voltage value of the power battery;

and the third determining submodule is used for judging that the power battery is in an undervoltage state when the current voltage value is smaller than the undervoltage protection value.

Optionally, the second determining sub-module includes:

and the detection submodule is used for acquiring the voltage value detected by the battery voltage sensor aiming at the power battery at preset time intervals.

Optionally, the under-voltage determination module further includes:

and the stopping submodule is used for judging that the power battery is not in an undervoltage state when the current voltage value is not less than the undervoltage protection value, and stopping correcting the SOC value of the power battery.

Optionally, the apparatus further comprises:

and the alarm module is used for sending voltage fault alarm information to the driver terminal.

Optionally, the apparatus further comprises:

and the adjusting module is used for adjusting the output power of the power battery according to the corrected SOC value.

Detailed description of the preferred embodiment

Based on the same inventive concept, an embodiment of the present invention further provides a vehicle, including:

a memory for storing controller executable instructions;

the controller is used for executing the SOC correction method of the power battery provided by the embodiment of the invention.

Detailed description of the invention

Based on the same inventive concept, embodiments of the present invention further provide a computer-readable storage medium, on which computer program instructions are stored, where the program instructions are executed by a processor to implement the steps of the SOC correction method for a power battery provided by the embodiments of the present invention.

The invention provides a method and a device for correcting SOC of a power battery, a vehicle and a storage medium, and belongs to the technical field of vehicles. Firstly, when a vehicle is in a running state, judging whether a power battery of the vehicle is in an undervoltage state or not according to the current voltage value of the power battery; then, under the condition that the power battery is in an undervoltage state, acquiring the current temperature, the current power and the current SOC value of the power battery; then, according to the temperature and the power value, inquiring a preset battery temperature-battery power-SOC relation chart, and determining a corresponding target SOC value; and finally, correcting the current SOC value according to the target SOC value. According to the method, when the vehicle is under-voltage in the running process, the SOC value can be automatically corrected by collecting the current working condition parameters and looking up the table, so that the problem that the battery is damaged due to continuous under-voltage caused by inaccurate SOC is avoided.

For simplicity of description, the method embodiments are described as a series of operational combinations, but those skilled in the art will recognize that the invention is not limited by the order of operation, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art will also appreciate that the embodiments described in the specification are presently preferred and that no requirement is necessarily placed on the invention for the exact operation and experimental conditions involved.

The SOC correction method, the SOC correction device, the vehicle and the storage medium for the power battery provided by the present invention are described in detail above, and specific examples are applied herein to illustrate the principle and the implementation of the present invention, and the description of the above embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A method for correcting SOC of a power battery is characterized by comprising the following steps:

and correcting the current SOC value according to the target SOC value.

2. The method according to claim 1, wherein the relationship chart comprises a plurality of battery power-SOC relationship curves at different temperatures, and the step 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 a corresponding target SOC value comprises:

3. The method as claimed in claim 1, wherein the battery temperature-battery power-SOC relation chart is obtained by simulating discharge conditions of the power battery under actual working conditions, and respectively measuring power values of the power battery under different temperature conditions and different SOC values, and then drawing the power battery.

4. The method according to claim 1, wherein the determining whether the power battery is in an undervoltage state according to the current voltage value of the power battery comprises:

detecting the current voltage value of the power battery;

5. The method according to claim 4, wherein the detecting the current voltage value of the power battery comprises:

6. The method of claim 4, further comprising:

7. The method of any of claims 1-6, wherein after determining that the power cell is under-voltage, the method further comprises:

and sending voltage fault alarm information to a driver terminal.

8. The method of any of claims 1-6, wherein after correcting the current SOC value, the method further comprises:

9. An SOC correction device for a power battery, comprising:

the undervoltage determining module is configured to judge whether the power battery is in an undervoltage state or not according to the current voltage value of the power battery when the vehicle is in a running state;

10. A vehicle, characterized in that the vehicle comprises:

a memory for storing controller executable instructions;

a controller for performing the method of any one of claims 1 to 8.

11. A computer-readable storage medium having computer program instructions stored thereon for execution by a processor to perform the steps of the method of any one of claims 1 to 8.