SOC correction method and device based on rapid OCV correction

Abstract

The invention relates to an SOC correction method and device based on rapid OCV correction. The method comprises the following steps: acquiring OCV test data, judging a standing working condition, acquiring an SOC estimated value after OCV correction, and correcting the SOC. According to the SOC correction method and device based on rapid OCV correction, the OCV characteristics of different time when the electric quantity of an LFP battery is 25% or below are utilized, and the problem that correction cannot be carried out in time due to the fact that the SOC error is too large under the non-full-charge working condition is effectively solved. By adopting the SOC correction method based on the rapid OCV correction, OCV correction can be triggered and the probability of OCV correction can be increased at the interval of traffic lights such as parking, so that the probability of SOC correction is increased, and the problem of inaccurate SOC caused by a long-term non-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-full-

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a SOC correction method and device based on fast OCV correction. Background Art

[0002] The battery management system has many functions, among which the SOC estimation function plays an important role. Since the accurate SOC value can help the vehicle system accurately estimate the remaining mileage of the vehicle, ensuring the accuracy of SOC is an extremely critical technical point.

[0003] The SOC estimation method of LFP batteries currently on the market is based on ampere-hour integration, and open circuit voltage correction and full calibration are used to eliminate the error of ampere-hour integration accumulation. However, due to the long platform period of LFP batteries, there is only an opportunity for open circuit voltage correction when the SOC is less than 25% or greater than 95% and it is left to stand for 1 hour, and the full charge calibration requires the vehicle to be charged to a single cell voltage of 3.65V. Due to differences in vehicle operation scenarios, such as PHEVs that cannot exhaust the power, online ride-hailing vehicles often stop automatically at 90%, and coupled with the limitations of some charging piles, many vehicles have long been unable to obtain full calibration opportunities, resulting in inaccurate SOC. In this way, car owners are likely to misjudge that the current SOC can meet the needs of this car use and continue to use the car, which is very likely to cause the vehicle to break down while driving.

[0004] At present, the method of calculating the SOC value of the battery at time t using the ampere-hour integration method is shown in the following formula:

[0005]

[0006] Among them, SOC t is the SOC value of the battery at time t, SOC0 is the SOC value of the battery's initial state, I is the instantaneous charge and discharge current of the battery, and C is the battery capacity.

[0007] Under ideal conditions, the above formula can calculate the battery SOC value and be used to calculate the remaining mileage of the vehicle. However, in actual operation, considering the acquisition error of the current I under different working conditions and the cumulative error of the BMS, as the algorithm running time increases, the error of the SOC value calculated using the above formula will become larger and larger, and eventually lose its reference significance.

[0008] However, due to the problem of cumulative error in ampere-hour integration, it is necessary to use open circuit voltage (OCV) correction to improve the accuracy of SOC (state of charge) estimation. The OCV (open circuit voltage) correction method means that according to the electrochemical characteristics of the battery, the state of charge SOC value of the battery and its open circuit voltage OCV have a specific corresponding relationship, so the accurate SOC value can be obtained by measuring the OCV of the battery. The prerequisite for triggering OCV correction is SOC < 25%. When the battery remains in a static state for ≥ 1h, the BMS obtains the lowest terminal voltage of the battery cell and obtains the OCV value of the battery; based on the OCV value, the accurate SOC value SOCocv can be obtained by checking the SOC-OCV curve of the battery.

[0009] In actual application scenarios, this correction mechanism faces many challenges. According to the battery parameters, when charging according to the charging MAP, the highest single cell voltage reaches 3.65V, then the charging can be considered complete and the SOC is set to 100%. In actual use scenarios, some charging piles on the market actively stop charging at SOC=95% to prevent safety accidents, making it impossible for the vehicle to be fully charged and calibrated. Some vehicles are operating vehicles and are rarely fully charged. For operation, most of them actively stop charging when the SOC is above 90%. At the same time, they rarely stay in place for more than 1 hour, so they rarely trigger the full charge correction and OCV correction strategies to update the battery SOC value. In these two scenarios, if the SOC is not calibrated for a long time, the accumulated error of the ampere-hour integral will increase, resulting in inaccurate SOC and increasing the risk of the vehicle breaking down on the road.

[0010] Therefore, there is an urgent need for an SOC correction method based on fast OCV correction to improve the SOC estimation accuracy and adapt to more practical scenarios. Summary of the invention

[0011] The purpose of the present invention is to provide a SOC correction method and device based on fast OCV correction, which can solve the problem in the prior art that the SOC is not allowed to run and the vehicle breaks down due to long-term under-charging.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A SOC correction method based on rapid OCV correction, the method comprising the following steps:

[0014] S1. Obtain OCV test data

[0015] The battery OCV test method is used to perform an OCV test on the battery at temperature T to obtain the static voltage corresponding to different SOC values ​​of the battery at different time points. According to the obtained test data, a table based on the battery SOC value, static voltage and static time is established.

[0016] OCV is the voltage of the battery under no-load conditions, and it has a direct relationship with SOC, and this relationship changes over time, especially more significantly at low SOC levels. Therefore, accurately mapping these relationships is crucial to accurately estimate SOC. By performing OCV tests on batteries at different SOC levels and resting times, a data table containing the relationship between SOC, resting voltage and resting time is established, and detailed OCV tests are introduced, including multiple time points and SOC levels, providing more comprehensive data support. The present invention solves the problem of SOC estimation error caused by changes in the OCV-SOC relationship over time and temperature, and improves the accuracy of SOC estimation, especially in the low SOC area.

[0017] S2. Determination of static working condition

[0018] Obtain the battery current and determine whether to enter the static working condition based on the battery current.

[0019] Only when the battery is at rest can its OCV be accurately measured, because the chemical reaction inside the battery has stabilized. Judging whether the battery is at rest (i.e. the current is less than the set threshold) avoids the error caused by measuring OCV during battery charging or discharging, ensures the accuracy of OCV measurement, and thus improves the reliability of SOC estimation.

[0020] S3. Obtain the estimated SOC value after OCV correction

[0021] After the battery enters the static condition, the current static time of the battery and the current battery cell voltage are obtained, and according to the current battery cell voltage and the current static time, the corresponding SOC value is determined as the SOC estimate SOCocv after OCV correction by querying a table based on the battery SOC value, static voltage and static time.

[0022] Real-time SOC estimation may be affected by many factors, such as temperature, aging, etc., and OCV-based estimation can provide a reference point independent of these factors. The measured rest time and cell voltage are used to query the pre-built data table to determine the corresponding SOC value as the corrected SOC estimate, which solves the error accumulation problem that may occur in real-time SOC estimation, provides an SOC estimate that is closer to the true value, and enhances the robustness of the system. The present invention allows OCV correction to be completed in a short time, increases the correction opportunity, and is particularly suitable for short-term stay scenarios.

[0023] S4, SOC correction

[0024] The current real SOC value RealSOC is obtained, and the SOC value is corrected according to the relationship between the real SOC value RealSOC and the SOC estimated value SOCocv.

[0025] Even with OCV correction, there may be some deviations, and a mechanism is needed to smoothly transition to the new estimated value. The estimated SOCocv is compared with the current real SOC (RealSOC), and the displayed SOC value (DispalySOC) is adjusted according to certain rules, which solves the confusion caused to users by sudden changes in the SOC estimate, achieves a smoother SOC display update, and improves the user experience. The present invention introduces a smooth correction coefficient so that the SOC display value can gradually and naturally follow the changes in the actual SOC, rather than abruptly jumping.

[0026] The present invention solves the problem of inaccurate SOC caused by long-term under-full discharge by introducing an OCV correction mechanism, especially triggering the correction during short stops such as parking gaps, and brings higher SOC estimation accuracy and more stable display results. In addition, the present invention also proposes a specific hardware device to implement this algorithm, making it easy to integrate into the existing battery management system, providing a more reliable energy management solution for electric vehicles and other applications.

[0027] As a further improvement of the above technical solution, in step S1, obtaining OCV test data includes:

[0028] S11. Obtain the static voltage corresponding to different SOC values ​​of the battery at different time points, including: recording the static voltage corresponding to the battery when the SOC value is 25%, 20%, 15%, 10%, and 5% at temperature T and the static time is 60S, 90S, 120S, 180S, 240S, 300S, 360S, 520S, 480S, 540S, 600S, 660S, 720S, 780S, 900S, 1800S, and 3600S respectively.

[0029] S12. According to the test data, a table based on the SOC value, rest voltage and rest time of the battery is established.

[0030] As a further improvement of the above technical solution, in step S1, the value of the temperature T is 25°C.

[0031] As a further improvement of the above technical solution, in step S2, obtaining the battery current and determining whether to enter the static working condition according to the battery current include:

[0032] The battery current is obtained. If the battery current is less than the set current threshold, it is determined that the battery enters the static working condition.

[0033] As a further improvement of the above technical solution, the current threshold is 3A.

[0034] As a further improvement of the above technical solution, in step S3, obtaining the estimated SOC value after OCV correction includes:

[0035] S31. After the battery enters a static working condition, the current static time of the battery is obtained.

[0036] S32: If the current rest time meets the requirement, the current battery cell voltage is obtained by using the battery management system BMS.

[0037] S33. According to the current battery cell voltage and the current rest time, by querying a table based on the battery SOC value, rest voltage and rest time, the corresponding SOC value is determined. The SOC value is the SOC estimated value SOCocv corrected by OCV.

[0038] As a further improvement of the above technical solution, in step S4, the SOC correction includes:

[0039] S41. Obtain the current real SOC value RealSOC.

[0040] S42. Compare the real SOC value RealSOC with the SOC estimated value SOCocv.

[0041] S43. If the estimated SOC value SOCocv is not equal to the real SOC value RealSOC, the real SOC value RealSOC is corrected to the estimated SOC value SOCocv; if the estimated SOC value SOCocv is equal to the real SOC value RealSOC, the real SOC value RealSOC does not need to be corrected.

[0042] S44. The displayed value DispalySOC follows the real SOC value RealSOC according to the set correction rate.

[0043] As a further improvement of the above technical solution, in step S44, if the real SOC value RealSOC and the displayed value DispalySOC are the same, the change rate of the displayed value DispalySOC and the real SOC value RealSOC is determined to be 1:1; if the displayed value DispalySOC and the real SOC value RealSOC are different during the following process, the smoothing correction coefficient is calculated according to the displayed value DispalySOC and the real SOC value RealSOC.

[0044] As a further improvement of the above technical solution, in step S44, when the vehicle is traveling, the real SOC value RealSOC is calculated according to the ampere-hour integral, and the display value DispalySOC is calculated according to the ampere-hour integral growth rate*smoothing correction coefficient.

[0045] The present invention also includes an SOC correction device based on rapid OCV correction, which includes: an OCV test data acquisition module, a static working condition determination module, a module for acquiring an SOC estimation value after OCV correction, and an SOC correction module.

[0046] The OCV test data acquisition module is used to perform an OCV test on the battery at temperature T using a battery OCV test method, obtain the static voltage corresponding to different SOC values ​​of the battery at different time points, and establish a table based on the battery's SOC value, static voltage and static time according to the acquired test data.

[0047] The stationary operating condition determination module is used to obtain the battery current and determine whether to enter the stationary operating condition according to the battery current.

[0048] The module for obtaining the estimated SOC value after OCV correction is used to obtain the estimated SOC value after OCV correction. After the battery enters the static working condition, the current static time of the battery and the current battery cell voltage are obtained, and according to the current battery cell voltage and the current static time, the corresponding SOC value is determined as the estimated SOC value SOCocv after OCV correction by querying a table based on the SOC value, static voltage and static time of the battery.

[0049] The SOC correction module is used to obtain the current real SOC value RealSOC, and correct the SOC value according to the relationship between the real SOC value RealSOC and the SOC estimated value SOCocv.

[0050] Compared with the prior art, the advantages of the present invention are:

[0051] The SOC correction method and device based on fast OCV correction described in the present invention utilize the OCV characteristics of the LFP battery at different times when the power level is below 25%, effectively solving the problem of too large SOC error and too late correction under the condition of not fully charged. The SOC correction method based on fast OCV correction described in the present invention can trigger OCV correction in the intervals of parking and waiting for traffic lights, increase the probability of OCV correction, and thus increase the probability of SOC correction, effectively solving the problem of inaccurate SOC caused by long-term not fully charged discharge scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a method flow chart of the SOC correction method based on rapid OCV correction in the present invention;

[0053] Figure 2 This is a table example diagram based on the battery's SOC value, resting voltage, and resting time;

[0054] Figure 3 is the smoothing correction coefficient setting diagram;

[0055] Figure 4 The curve after SOC correction using the method of the present invention is Figure 1 ;

[0056] Figure 5 The curve after SOC correction using the method of the present invention is Figure 2 . DETAILED DESCRIPTION

[0057] The present invention will be further described below in conjunction with the accompanying drawings:

[0058] The present invention proposes a SOC correction method based on fast OCV correction, which can solve the problem of SOC inaccurate driving and vehicle breakdown due to long-term under-charging.

[0059] like Figure 1 As shown, the SOC correction method based on rapid OCV correction includes the following steps:

[0060] S1. Obtain OCV test data

[0061] The battery OCV test method is used to perform an OCV test on the battery at temperature T, and the corresponding static voltage of the battery at different SOC values ​​at different time points is obtained. According to the obtained test data, a table based on the battery SOC value, static voltage and static time is established. Preferably, the temperature T is 25°C.

[0062] In this embodiment, the static voltage corresponding to different SOC values ​​of the battery at different time points is obtained, including: recording the static voltage corresponding to the battery at 25°C when the SOC value is 25%, 20%, 15%, 10%, and 5%, and the static time is 60S, 90S, 120S, 180S, 240S, 300S, 360S, 520S, 480S, 540S, 600S, 660S, 720S, 780S, 900S, 1800S, and 3600S. According to the data obtained from the test, a table based on the SOC value, static voltage, and static time of the battery is established, such as Figure 2 As shown. Since the relationship between voltage change and time is the basis for fast OCV to obtain SOC, the present invention can quickly obtain the relationship between voltage change and time at different SOCs of the battery at 25°C by establishing a table based on the SOC value, static voltage and static time of the battery, thereby obtaining the SOC value.

[0063] S2. Determination of static working condition

[0064] The battery current is obtained, and whether the battery enters the static state is determined according to the battery current. If the battery current is less than a set current threshold, the battery is determined to enter the static state. Preferably, the current threshold is 3A.

[0065] S3. Obtain the estimated SOC value after OCV correction

[0066] After the battery enters the static condition, the current static time of the battery is obtained. If the current static time meets the requirements, the battery management system BMS is used to obtain the current battery cell voltage, and according to the current battery cell voltage and the current static time, the corresponding SOC value is determined by querying the table based on the battery's SOC value, static voltage and static time. The SOC value is the SOC estimated value SOCocv corrected by OCV. The battery management system BMS needs to determine whether a certain scene in the operation of the vehicle can start the fast OCV strategy based on this condition. Among them, the static time is not a fixed value. The static time meets the requirements, which means that the static time is within the static time range contained in the table based on the battery's SOC value, static voltage and static time. Different static times correspond to a voltage value. According to the static time and the current voltage, the corresponding SOC value can be obtained through a table based on the battery's SOC value, static voltage and static time. The SOC value is the SOC estimated value SOCocv.

[0067] S4, SOC correction

[0068] The current real SOC value RealSOC is obtained, and the real SOC value RealSOC is compared with the SOC estimated value SOCocv. If the SOC estimated value SOCocv and the real SOC value RealSOC are not equal, the real SOC value RealSOC is corrected to the SOC estimated value SOCocv, and the displayed value DispalySOC follows the real SOC value RealSOC at a certain correction rate. If the SOC estimated value SOCocv and the real SOC value RealSOC are equal, the real SOC value RealSOC does not need to be corrected. In step S4, the current battery SOC estimated value SOCocv is obtained through the OCV data using the method described in step S3, and compared with the current real SOC value RealSOC calculated by the battery management system BMS. According to the comparison result, the SOC display value DispalySOC is adjusted, and the user determines whether to find a charging pile for charging according to the SOC display value.

[0069] Combined with the SOC calibration strategy at the charging end, the SOC accuracy can be improved, and the problem of excessive SOC error caused by long-term lack of full charge calibration can be avoided to a certain extent. The SOC (State of Charge) calibration strategy at the charging end is an important part of ensuring the accuracy of SOC estimation in the battery management system (BMS) in the prior art. SOC calibration at the end of charging can correct the accumulated error and ensure that the SOC display value is consistent with the actual charge. Choosing a suitable SOC calibration strategy at the charging end depends on the specific application requirements, hardware limitations and the desired level of accuracy. In actual applications, adjustments and optimizations are required according to specific circumstances.

[0070] When the current is less than 3A, it enters the static condition. After the static time is met, the battery management system BMS obtains the current battery cell voltage and the current static time, and then looks up the table to obtain the corresponding SOC estimation value SOCocv, which is then compared with the current real SOC value RealSoc. When SOCocv≠RealSOC, the real SOC value RealSOC is corrected to the SOC estimation value SOCocv; and the SOC display value DispalySOC follows the real SOC value RealSOC at a certain correction rate. Among them, the static time is not a fixed value. Meeting the static time means that the static time is within the static time range contained in the table based on the battery's SOC value, static voltage and static time. Different static times correspond to a voltage value. According to the static time and the current voltage, the corresponding SOC value can be obtained through a table based on the battery's SOC value, static voltage and static time. This SOC value is the SOC estimation value SOCocv. The SOC value can smoothly and accurately reflect the true state of charge of the battery while avoiding poor user experience due to rapid changes or sudden jumps. The specific SOC correction rate can be defined as the maximum change allowed per minute or per second. For example, some systems may stipulate that DisplaySOC can complete the correction from the current value to the new value within a few minutes, depending on the needs of the application. Depending on different application scenarios (such as static, low-speed driving, high-speed driving, etc.), the correction rate can also be dynamically adjusted. For example, while the vehicle is stopped, a slower correction rate can be used; while in the driving process, the correction speed can be appropriately accelerated according to the actual situation.

[0071] When the real SOC value RealSOC and the SOC display value DispalySOC are the same, the change rate of the SOC display value DispalySOC and the real SOC value RealSOC is 1:1; when the SOC display value DispalySOC and the real SOC value RealSOC are different during the following process, the smoothing correction coefficient is calculated based on the SOC display value DispalySOC and the real SOC value RealSOC. When the vehicle is driving, the real SOC is calculated according to the normal ampere-hour integral, and the SOC display value DispalySOC is calculated according to the normal ampere-hour integral growth rate * smoothing correction coefficient. In order to prevent the smoothing correction coefficient from being too large and causing the SOC to change too quickly, the smoothing correction coefficient is set as follows: Figure 3 Limitations shown.

[0072] like Figure 4 As shown, the SOC is calibrated to 28%, the SOC is artificially high by 20%, and the rapid OCV correction is triggered after standing for 170 seconds. The OCV rapid correction method of the present invention is used to correct it to 11.4%, which is 0.4% different from the SOC calculated by ampere-hour integration.

[0073] like Figure 5 As shown, the SOC is calibrated to 28%, the SOC is 20% higher, and the real SOC triggers a fast OCV correction to 11.4%. Then the discharge is followed, and the SOC displayed at the end is consistent with the real SOC. The method in the prior art requires standing for 1 hour in the non-plateau period to trigger the OCV correction. Combined with the vehicle operation scenario, the probability of triggering the OCV correction and thus calibrating the SOC is relatively low.

[0074] exist Figure 4 and Figure 5 In the figure, the horizontal axis represents time in seconds, and the vertical axis represents SOC in %. Figure 4 and Figure 5 In the example, the SOC is calibrated to 28%, that is, the current SOC value is assumed to be 28%, while the actual SOC value is 8%. Therefore, the SOC is falsely high by 20%. Based on the method described in the present invention, the SOC is corrected, and the corrected result is 11.4%. This result is obtained by measuring the voltage in the table based on the SOC value, static voltage and static time of the battery. The corrected result is 11.4%, which is 3.4% different from the actual SOC value of 8%, which meets the industry's requirements for SOC accuracy (not more than 5%), indicating that the accuracy of the SOC correction method described in the present invention is very high.

[0075] In the industry, everyone tends to use the voltage data of the battery after it has been stationary for 1 hour to obtain the SOC. This method increases the data sampling points and the probability of triggering OCV, thereby solving the problem of inaccurate SOC in specific customer vehicle use scenarios. However, due to operational needs, electric taxi drivers often do not fully charge their vehicles, which will lead to inaccurate SOC and frequent vehicle stalling. After using the method described in the present invention, even if the driver uses the vehicle according to their habits, the SOC can be calibrated, and the vehicle will not stall halfway.

[0076] The present invention also includes an SOC correction device based on rapid OCV correction, which includes: an OCV test data acquisition module, a static working condition determination module, a module for acquiring an SOC estimation value after OCV correction, and an SOC correction module.

[0077] The OCV test data acquisition module is used to perform an OCV test on the battery at temperature T using a battery OCV test method, obtain the static voltage corresponding to different SOC values ​​of the battery at different time points, and establish a table based on the battery's SOC value, static voltage and static time according to the acquired test data.

[0078] The stationary operating condition determination module is used to obtain the battery current and determine whether to enter the stationary operating condition according to the battery current.

[0079] The module for obtaining the estimated SOC value after OCV correction is used to obtain the estimated SOC value after OCV correction. After the battery enters the static working condition, the current static time of the battery and the current battery cell voltage are obtained, and according to the current battery cell voltage and the current static time, the corresponding SOC value is determined as the estimated SOC value SOCocv after OCV correction by querying a table based on the SOC value, static voltage and static time of the battery.

[0080] The SOC correction module is used to obtain the current real SOC value RealSOC, and correct the SOC value according to the relationship between the real SOC value RealSOC and the SOC estimated value SOCocv.

[0081] In summary, the SOC correction method and device based on rapid OCV correction described in the present invention utilize the OCV characteristics of the LFP battery at different times when the power level is below 25%, effectively solving the problem of too large SOC error and too late to correct under the condition of not fully charged. The SOC correction method based on rapid OCV correction described in the present invention can trigger OCV correction in the intervals of parking and waiting for traffic lights, increase the probability of OCV correction, and thus increase the probability of SOC correction, effectively solving the problem of inaccurate SOC caused by long-term not fully charged discharge scenarios.

[0082] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A SOC correction method based on fast OCV correction, characterized in that: The method comprises the following steps: S1. Obtain OCV test data Perform an OCV test on the battery at temperature T using a battery OCV test method to obtain the corresponding static voltage of the battery at different SOC values ​​at different time points, and establish a table based on the battery's SOC value, static voltage, and static time based on the obtained test data; S2. Determination of static working condition Obtain the battery current and determine whether to enter the static working state according to the battery current; S3. Obtain the estimated SOC value after OCV correction After the battery enters the static working condition, the current static time of the battery and the current battery cell voltage are obtained, and according to the current battery cell voltage and the current static time, the corresponding SOC value is determined as the SOC estimation value SOCocv after OCV correction by querying a table based on the SOC value, static voltage and static time of the battery; S4, SOC correction The current real SOC value RealSOC is obtained, and the SOC value is corrected according to the relationship between the real SOC value RealSOC and the SOC estimated value SOCocv.

2. The SOC correction method based on rapid OCV correction according to claim 1, characterized in that: In step S1, obtaining OCV test data includes: S11. Obtain the static voltage corresponding to different SOC values ​​of the battery at different time points, including: recording the static voltage corresponding to the battery when the SOC values ​​are 25%, 20%, 15%, 10%, and 5% at temperature T and the static time is 60S, 90S, 120S, 180S, 240S, 300S, 360S, 520S, 480S, 540S, 600S, 660S, 720S, 780S, 900S, 1800S, and 3600S respectively; S12. According to the test data, a table based on the SOC value, rest voltage and rest time of the battery is established.

3. The SOC correction method based on rapid OCV correction according to claim 1 or 2, characterized in that: In the step S1, the temperature T is set to 25°C.

4. The SOC correction method based on rapid OCV correction according to claim 1, characterized in that: In step S2, the obtaining of the battery current and determining whether to enter the static working state according to the battery current include: The battery current is obtained. If the battery current is less than the set current threshold, it is determined that the battery enters the static working condition.

5. The SOC correction method based on rapid OCV correction according to claim 4, characterized in that: The current threshold is 3A.

6. The SOC correction method based on rapid OCV correction according to claim 1, characterized in that: In step S3, obtaining the estimated SOC value after OCV correction includes: S31, after the battery enters the static working condition, obtaining the current static time of the battery; S32, if the current rest time meets the requirement, obtain the current battery cell voltage using the battery management system BMS; S33. According to the current battery cell voltage and the current rest time, by querying a table based on the battery SOC value, rest voltage and rest time, the corresponding SOC value is determined. The SOC value is the SOC estimated value SOCocv corrected by OCV.

7. The SOC correction method based on rapid OCV correction according to claim 1, characterized in that: In step S4, the SOC correction includes: S41, obtaining the current real SOC value RealSOC; S42, comparing the real SOC value RealSOC with the SOC estimated value SOCocv; S43, if the estimated SOC value SOCocv is not equal to the real SOC value RealSOC, the real SOC value RealSOC is corrected to the estimated SOC value SOCocv; if the estimated SOC value SOCocv is equal to the real SOC value RealSOC, the real SOC value RealSOC does not need to be corrected; S44. The displayed value DispalySOC follows the real SOC value RealSOC according to the set correction rate.

8. The SOC correction method based on rapid OCV correction according to claim 7, characterized in that: In the step S44, if the real SOC value RealSOC and the displayed value DispalySOC are the same, then the change rate of the displayed value DispalySOC and the real SOC value RealSOC is determined to be 1:1; If the displayed value DispalySOC and the real SOC value RealSOC are different during the following process, the smoothing correction coefficient is calculated according to the displayed value DispalySOC and the real SOC value RealSOC.

9. The SOC correction method based on rapid OCV correction according to claim 8, characterized in that: In the step S44, when the vehicle is running, the real SOC value RealSOC is calculated according to the ampere-hour integration, and the display value DispalySOC is calculated according to the ampere-hour integration growth rate*smoothing correction coefficient.

10. A SOC correction device based on fast OCV correction, characterized in that: The device comprises: an OCV test data acquisition module, a static working condition determination module, an SOC estimation value acquisition module after OCV correction, and an SOC correction module; The OCV test data acquisition module is used to perform an OCV test on the battery at a temperature T using a battery OCV test method, obtain the static voltage corresponding to different SOC values ​​of the battery at different time points, and establish a table based on the SOC value, static voltage and static time of the battery according to the acquired test data; The static working condition determination module is used to obtain the battery current and determine whether to enter the static working condition according to the battery current; The module for obtaining the estimated SOC value corrected by OCV is used to obtain the estimated SOC value corrected by OCV, obtain the current rest time of the battery and the current battery cell voltage after the battery enters the rest condition, and determine the corresponding SOC value as the estimated SOC value SOCocv corrected by OCV by querying a table based on the SOC value, rest voltage and rest time of the battery according to the current battery cell voltage and the current rest time; The SOC correction module is used to obtain the current real SOC value RealSOC, and correct the SOC value according to the relationship between the real SOC value RealSOC and the SOC estimated value SOCocv.

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