CN116953522A

CN116953522A - SOC-OCV mapping relation calibration method, device, equipment, medium and product

Info

Publication number: CN116953522A
Application number: CN202310791235.6A
Authority: CN
Inventors: 贺国达; 陈英杰
Original assignee: Xiamen Xinnengda Technology Co Ltd
Current assignee: Xiamen Xinnengda Technology Co Ltd
Priority date: 2023-06-29
Filing date: 2023-06-29
Publication date: 2023-10-27

Abstract

The application discloses a method, a device, equipment, a medium and a product for calibrating an SOC-OCV mapping relation, wherein the method comprises the following steps: receiving a first state of charge, SOC, and a first number of cycles of the battery pack; acquiring a first OCV corresponding to a first SOC; determining a first SOC-OCV mapping relation corresponding to a first cycle number based on preset experimental data; experimental data is configured as a function between cycle number, OCV and SOC; determining a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship; the first SOC-OCV mapping relationship is calibrated based on the first SOC, the first OCV, and the first calibrated OCV.

Description

SOC-OCV mapping relation calibration method, device, equipment, medium and product

Technical Field

The application relates to the field of batteries, in particular to a method, a device, equipment, a medium and a product for calibrating an SOC-OCV mapping relation.

Background

The State of Charge (SOC) -open circuit voltage (Open circuit voltage, OCV) curve is an important performance indicator of a battery.

In the prior art, when calibrating the SOC-OCV curve of the battery pack, the SOC-OCV curve of the battery pack at different temperatures is usually calibrated.

Disclosure of Invention

The application provides a method, a device, equipment, a medium and a product for calibrating an SOC-OCV mapping relation, which are used for solving the problem of inaccurate SOC-OCV curve in the prior art.

In a first aspect, the present application provides a method for calibrating an SOC-OCV mapping relationship. The method comprises the following steps: receiving a first state of charge (SOC) and a first cycle number of the battery pack, and acquiring a first OCV corresponding to the first SOC; determining a first SOC-OCV mapping relationship corresponding to a first cycle number based on preset experimental data configured as a function of the cycle number, the OCV and the SOC; determining a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship; the first SOC-OCV mapping relationship is calibrated based on the first SOC, the first OCV, and the first calibrated OCV.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the first SOC and the first cycle number of the battery pack can be received, the first OCV corresponding to the first SOC can be obtained, then the first SOC-OCV mapping relation corresponding to the first cycle number is determined based on preset experimental data, the experimental data is configured as a function among the cycle number, the OCV and the SOC, the first calibration OCV corresponding to the first SOC can be determined based on the first SOC-OCV mapping relation, and then the first SOC-OCV mapping relation can be calibrated based on the first SOC, the first OCV and the first calibration OCV. Because the first calibration OCV is determined based on the first SOC-OCV mapping relation corresponding to the first cycle times, the influence of the battery pack cycle aging on the SOC-OCV mapping relation is considered, so that the accuracy of the first calibration OCV is higher, and the accuracy of the SOC-OCV mapping relation is improved by calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

In some embodiments, the acquiring the first OCV corresponding to the first SOC includes: responsive to the battery pack satisfying the first condition, collecting a second OCV of the battery pack, the second OCV configured as an OCV of the battery pack after the battery pack has been stationary for a first time; the first condition is configured such that during the second time, the throughput capacity of the battery pack is less than the nominal capacity of the battery pack; taking the second OCV as the first OCV; the second time is configured as the time that the battery pack is charged or discharged from the second SOC to the first SOC, the second time is smaller than a second time threshold, the throughput capacity of the battery pack is configured as the sum of the charge accumulation capacity and the discharge accumulation capacity of the battery pack in the second time, and the second SOC is configured as the SOC obtained after calibration.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the accuracy of the SOC is higher in a short time after the SOC is calibrated and the throughput is smaller, the acquired second OCV is used as the first OCV corresponding to the first SOC, and the OCV of the battery is more accurate.

In some embodiments, the second SOC is calibrated by one of the following calibration terms: i) Responding to the SOC of any battery cell to a first SOC range when the battery pack is charged or discharged, standing for a third time to obtain the current OCV of the battery pack, and calibrating to obtain a second SOC based on the current OCV and experimental data; ii) when the battery pack is charged, the voltage of any battery cell is larger than the charging cut-off voltage and the charging current is smaller than the first current threshold value, and the time of T1 is continued, and the second SOC is calibrated to be 100%; iii) And when the battery pack discharges, the voltage of any battery cell is smaller than the discharge cut-off voltage, the discharge current is smaller than the second current threshold value, and the second SOC is calibrated to be 0% after the time of T2.

The SOC-OCV mapping relation calibration method provided by the embodiment of the application can accurately calibrate the SOC so as to more accurately calibrate the SOC-OCV mapping relation.

In some embodiments, the difference between different SOCs corresponding to the same OCV is less than a preset threshold for different cycles over the first SOC range.

The SOC-OCV mapping relation calibration method provided by the embodiment of the application can calibrate the SOC more accurately in the range of small SOC variation.

In some embodiments, calibrating the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV includes: and determining a plurality of target SOCs from the first SOC-OCV mapping relation, wherein the target SOCs are configured into SOCs which are arranged at intervals of x percent, x is more than or equal to 1 and less than or equal to 10, and calibrating target OCVs corresponding to the target SOCs to obtain target OCV calibration values. Wherein the target OCV is configured to obtain an OCV corresponding to the target SOC based on the experimental data.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the target OCV corresponding to the target SOCs can be determined by calibrating the target OCVs corresponding to the target SOCs respectively, and then the calibrated first SOC-OCV mapping relation can be determined based on the target OCV corresponding to the target SOCs respectively, so that the calibrated first SOC-OCV mapping relation can be more accurate.

In some embodiments, the first SOC is a plurality of SOCs; the calibrating the target OCV corresponding to the target SOC to obtain a target OCV calibration value includes: determining a first SOC having the smallest absolute value of a difference from a target SOC from among a plurality of first SOCs, and a first calibration OCV corresponding to the first SOC; calculating a first OCV difference value, wherein the first OCV difference value is the difference value between the first calibration OCV and the first OCV; calculating a target first OCV calibration value based on the first OCV difference value; the target OCV calibration value is calculated based on the target OCV corresponding to the target SOC and the first OCV calibration value.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the first OCV difference value corresponding to the target SOC can be determined based on the first calibration OCV corresponding to the first SOC nearest to the target SOC and the first OCV, and then the target OCV calibration value corresponding to the target SOC is gradually calculated, so that the OCV corresponding to the target SOC is accurately calibrated.

In some embodiments, the calculating the target first OCV calibration value based on the first OCV difference value includes: calculating a target first OCV calibration value based on the first OCV difference value, the voltage sampling error coefficient, the current sampling error coefficient and the standing time length error coefficient; wherein the voltage sampling error coefficient is configured to be associated with an error of the voltage sampling chip; the current sampling error coefficient is configured as a function of an error associated with the current sampling chip, the second time threshold, a nominal capacity of the battery pack, and a throughput capacity of the battery pack; the rest duration error coefficient is configured to be associated with a first time and a first time threshold that is a function of a maximum time for which the battery pack is stationary to satisfy the first condition.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the target first OCV calibration value corresponding to the target SOC can be more accurately determined through the first OCV difference value, the voltage sampling error coefficient, the current sampling error coefficient and the standing time length error coefficient, so that the SOC-OCV mapping relation can be more accurately calibrated.

In some embodiments, the target OCV calibration value is an OCV obtained after the battery pack is calibrated in the first state; the method further comprises the steps of: and calibrating the SOC-OCV mapping relation of the battery pack in the second state based on the target OCV calibration value. The first state is one of a charging state and a discharging state of the battery pack, and the second state is the other of the charging state and the discharging state of the battery pack.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the SOC-OCV mapping relation in the discharging state can be calibrated based on the target OCV calibration value in the charging state, or the SOC-OCV mapping relation in the charging state can be calibrated based on the target OCV calibration value in the discharging state, so that the calibration efficiency can be improved.

In some embodiments, calibrating the OSC-OCV mapping of the battery pack in the second state based on the target OCV calibration value further includes: determining a third SOC of the battery pack in the second state, the third SOC corresponding to a target SOC of the battery pack in the first state; determining a third OCV corresponding to the third SOC based on the experimental data; calculating the difference value between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N difference values, and calculating the average value of the N difference values to obtain deviation; based on the deviation and the third OCV, the SOC-OCV map of the battery pack in the second state is calibrated.

According to the SOC-OCV mapping relation calibration method provided by the embodiment of the application, the SOC-OCV mapping relation is calibrated based on the difference relation between the charged OCV and the discharged OCV, so that the accuracy of calibrating the SOC-OCV mapping relation in the discharged state based on the target OCV calibration value in the charged state or calibrating the SOC-OCV mapping relation in the charged state based on the target OCV calibration value in the discharged state can be improved.

In a second aspect, the present application provides an SOC-OCV map calibration apparatus, including: the receiving module is used for receiving the first state of charge (SOC) and the first cycle times of the battery pack; an acquisition module for acquiring a first OCV corresponding to a first SOC; the first determining module is used for determining a first SOC-OCV mapping relation corresponding to the first cycle number based on preset experimental data; experimental data is configured as a function between cycle number, OCV and SOC; the second determining module is used for determining a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relation; the first calibration module is used for calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

According to the SOC-OCV mapping relation calibration device provided by the embodiment of the application, the first SOC and the first cycle times of the battery pack can be received, the first OCV corresponding to the first SOC can be obtained, then the first SOC-OCV mapping relation corresponding to the first cycle times is determined based on preset experimental data, the experimental data is configured as a function among the cycle times, the OCV and the SOC, the first calibration OCV corresponding to the first SOC can be determined based on the first SOC-OCV mapping relation, and then the first SOC-OCV mapping relation can be calibrated based on the first SOC, the first OCV and the first calibration OCV. Because the first calibration OCV is determined based on the first SOC-OCV mapping relation corresponding to the first cycle times, the influence of the battery pack cycle aging on the SOC-OCV mapping relation is considered, so that the accuracy of the first calibration OCV is higher, and the accuracy of the SOC-OCV mapping relation is improved by calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

In a third aspect, the present application provides an electronic device, the device comprising: a processor and a memory storing computer program instructions;

the processor, when executing the computer program instructions, implements the SOC-OCV mapping relation calibration method as shown in any one of the embodiments of the first aspect.

In a fourth aspect, the present application provides a computer storage medium having stored thereon computer program instructions which, when executed by a processor, implement the SOC-OCV map calibration method shown in any one of the embodiments of the first aspect.

In a fifth aspect, embodiments of the present application provide a computer program product, instructions in which, when executed by a processor of an electronic device, cause the electronic device to perform the SOC-OCV map calibration method shown in any of the embodiments of the first aspect.

The method, the device, the equipment, the medium and the product for calibrating the SOC-OCV mapping relation provided by the embodiment of the application can receive the first SOC and the first cycle times of the battery pack, acquire the first OCV corresponding to the first SOC, then determine the first SOC-OCV mapping relation corresponding to the first cycle times based on preset experimental data, the experimental data is configured as a function among the cycle times, the OCV and the SOC, determine the first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relation, and calibrate the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV. Because the first calibration OCV is determined based on the first SOC-OCV mapping relation corresponding to the first cycle times, the influence of the battery pack cycle aging on the SOC-OCV mapping relation is considered, so that the accuracy of the first calibration OCV is higher, and the accuracy of the SOC-OCV mapping relation is improved by calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

Drawings

Features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

FIG. 1 is a flow chart of a calibration method for SOC-OCV mapping relation according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an SOC-OCV curve according to an embodiment of the present application;

FIG. 3 is a schematic diagram illustrating a structure of an SOC-OCV mapping relation calibration device according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the application.

In the drawings, the drawings are not necessarily to scale.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

As background art, state of Charge (SOC) -open circuit voltage (Open circuit voltage, OCV) curve is an important performance indicator of a battery pack.

When calibrating the SOC-OCV curve of the battery pack, the SOC-OCV curve of the battery pack can be calibrated at different temperatures.

However, the actual SOC-OCV curve of the battery pack changes after the battery pack is cycled, and the influence of the battery pack cycle aging on the SOC-OCV curve is not considered in the prior art, so that the calibration of the SOC-OCV curve in the prior art is low in accuracy.

First, a detailed description will be given of an SOC-OCV mapping relation calibration method provided in an embodiment of the present application with reference to fig. 1.

Fig. 1 is a flow chart illustrating an SOC-OCV mapping relation calibration method according to an embodiment of the present application, which is to be noted that the SOC-OCV mapping relation calibration method may be applied to an SOC-OCV mapping relation calibration apparatus, such as a battery management system (Battery Management System, BMS). In some embodiments of the present application, the battery management system may be embodied in the form of a printed circuit board, and various electronic components may be disposed on the battery management system to implement the calibration method of the present application, where the electronic components may include a microcontroller, an analog front end, a charge switch, a discharge switch, a fuse, a capacitor, a resistor, and the like.

As shown in fig. 1, the SOC-OCV mapping relation calibration method may include the steps of:

s110, receiving a first state of charge (SOC) and a first cycle number of the battery pack;

s120, acquiring a first OCV corresponding to the first SOC;

s130, determining a first SOC-OCV mapping relation corresponding to a first cycle number based on preset experimental data;

s140, determining a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relation;

S150, calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

Thus, a first SOC and a first number of cycles of the battery pack may be received, and a first OCV corresponding to the first SOC may be acquired, and then a first SOC-OCV map corresponding to the first number of cycles may be determined based on preset experimental data configured as a function between the number of cycles, the OCV, and the SOC, and based on the first SOC-OCV map, a first calibrated OCV corresponding to the first SOC may be determined, and then the first SOC-OCV map may be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Because the first calibration OCV is determined based on the first SOC-OCV mapping relation corresponding to the first cycle times, the influence of the battery pack cycle aging on the SOC-OCV mapping relation is considered, so that the accuracy of the first calibration OCV is higher, and the accuracy of the SOC-OCV mapping relation is improved by calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

Referring to S110, the calibration SOC-OCV map may be to calibrate OCVs corresponding to a plurality of SOCs, respectively. Considering the influence of battery pack aging on the SOC-OCV mapping relation, the SOC-OCV mapping relation under a plurality of different cycle times can be pre-calibrated, and then the SOC-OCV mapping relation under the plurality of different cycle times is respectively calibrated.

For example, the number of different cycles may be 10, 200, 300, 500, 700, 1000, or the like, or may be selected according to y=100×x+10, where y is the number of cycles, and x is 1,2, … n. The application does not limit the number of different cycles.

Battery cycle number= (charge accumulation capacity + discharge accumulation capacity)/(2 x Capstd), where Capstd is the nominal capacity of the battery pack.

Here, the first cycle number may be a cycle number corresponding to the SOC-OCV map to be calibrated.

Referring to S120, the first OCV may be an OCV test value corresponding to the first SOC, which may be used to calibrate a calibrated OCV corresponding to the first SOC. In one specific implementation, the OCV of the battery pack in the inactive state (i.e., the rest state) may be collected through an analog front end on the BMS.

In some embodiments, to obtain a more accurate first OCV, S120 may include:

responsive to the battery pack satisfying the first condition, collecting a second OCV of the battery pack;

the second OCV is taken as the first OCV.

Wherein the second OCV may be configured as an OCV of the battery pack after the battery pack is left standing for the first time. The first condition may be configured such that the throughput capacity of the battery pack is less than the nominal capacity of the battery pack during the second time. The second time may be configured as a time that the battery pack has elapsed from the charging or discharging of the second SOC to the first SOC, and the second time is less than a second time threshold. The throughput capacity of the battery pack may be configured to be a sum of the charge accumulated capacity and the discharge accumulated capacity of the battery pack during the second time. The second SOC may be configured as a calibrated SOC.

Here, the battery pack satisfying the first condition may indicate that the time from the previous calibration of the SOC is short, and it may be considered that the SOC at this time, i.e., the first SOC, is also accurate, and thus the second OCV may be acquired through the analog front end.

For example, if the battery pack is a lithium iron battery, the first time may be any time greater than 20 minutes and less than 60 minutes; if the battery pack is a ternary battery, the first time may be any time greater than 10 minutes and less than 30 minutes. The second time may be 48 hours.

Therefore, when the SOC is calibrated for a short time and the throughput is small, the accuracy of the SOC is still high, and the acquired second OCV is used as the first OCV corresponding to the first SOC, so that the accuracy is high.

In some embodiments, to improve accuracy of the SOC-OCV mapping, the second SOC may be calibrated by one of the following calibration terms:

i) Responding to the SOC of any battery cell to a first SOC range when the battery pack is charged or discharged, standing for a third time to obtain the current OCV of the battery pack, and calibrating to obtain a second SOC based on the current OCV and experimental data;

ii) when the battery pack is charged, the voltage of any one of the battery cells is larger than the charge cut-off voltage and the charge current is smaller than the first current threshold value, and the time of T1 is continued, and the second SOC is calibrated to be 100%;

iii) And when the battery pack discharges, the voltage of any battery cell is smaller than the discharge cut-off voltage, the discharge current is smaller than the second current threshold value, and the second SOC is calibrated to be 0% after the time of T2.

Here, the second SOC may be a calibrated SOC. The SOC of the battery pack may be selected to be in the first SOC range, the full charge point, and the discharge cut-off point as SOC calibration points.

In some embodiments, to more accurately calibrate the SOC, the difference between different SOCs corresponding to the same OCV is less than a preset threshold at different cycles within the first SOC range.

That is, the first SOC range may be a range in which the SOC corresponding to the same OCV does not change much at different cycle times. The calibration of the SOC is more accurate in the range where the SOC does not change much.

Illustratively, the first SOC range may be SOC < X1% and SOC > X2%, where X1% may be 14% and X2% may be 96%. The positions of X1% and X2% may be as shown in fig. 2.

Illustratively, the third time may be 20 minutes. If the positive electrode material of the battery core is lithium iron phosphate, the charge cut-off voltage can be 3.6V or 3.65V, and the discharge cut-off voltage can be set to be between 2.0V and 2.5V; if the positive electrode material of the battery core is nickel cobalt manganese (i.e., ternary battery core), the charge cut-off voltage can be 4.2V or 4.25V, and the discharge cut-off voltage can be set between 2.5V and 3.2V. The first current threshold and the second current threshold may each be 0.1C. The time T1 and the time T2 may each be any time greater than 3s and less than 10 s.

For example, after SOC of any one cell is less than 14% or greater than 96% and left for 20min when the battery pack is charged or discharged, the current OCV may be collected and the OCV-SOC curve calibrated in the test chamber is verified using the current OCV, with the queried SOC as the second SOC. When the battery pack is charged, any one of the battery cells of the battery pack has a voltage greater than 3.6V and a charging current less than 0.1C for 5 seconds, the second SOC can be calibrated to be 100%. When the battery pack is discharged, the voltage of any cell of the battery pack is less than 2V, the discharge current is less than 0.1C, and the second SOC can be calibrated to be 0% for 5 seconds.

In this way, the SOC can be accurately calibrated so as to more accurately calibrate the SOC-OCV mapping relationship.

Referring to S130, experimental data may be configured as a function between cycle number, OCV, and SOC.

For example, experimental data may be obtained by calibrating the SOC-OCV mapping relationship under different cycle numbers in a laboratory in advance, and storing the SOC-OCV curves under different cycle numbers in a register of the BMS according to each X% SOC, for example, when X is 5, the SOC is 0%,5%,10%, …,95%,100%. The fitting coefficients can also be stored as tables by using polynomials to fit SOC-OCV curves at different cycle times.

For example, the battery pack may be controlled to start discharging from full charge at a certain cycle number, and left to stand for 120min after each 5% SOC is discharged, and the OCV corresponding to the SOC is collected until the OCV is less than 2.0V (discharge cut-off voltage), so as to obtain a plurality of SOCs and OCVs corresponding to the SOCs respectively. And the battery pack can be controlled to start charging from full charge, and the battery pack is kept stand for 120min after 5% of SOC is charged, so that the OCV corresponding to the SOC is collected until the OCV is more than 3.6V (charge cut-off voltage), and a plurality of SOCs and the OCVs corresponding to the SOCs are obtained.

Specifically, the experimental data may include SOC-OCV mappings corresponding to a plurality of cycle numbers, from which a first SOC-OCV mapping corresponding to a first cycle number may be found.

If the pre-calibrated experimental data does not include the SOC-OCV mapping relation corresponding to the first cycle number, the SOC-OCV mapping relation corresponding to the first cycle number can be interpolated according to the SOC-OCV mapping relation under different cycle numbers.

Referring to S140, an OCV corresponding to the first SOC in the first SOC-OCV map may be used as the first calibration OCV.

Referring to S150, OCVs corresponding to a plurality of SOCs may be calibrated based on the first SOC, the first OCV, and the first calibration OCV, respectively, to calibrate the first SOC-OCV map.

In some embodiments, in order to more accurately calibrate the SOC-OCV mapping relationship, S150 may include:

determining a plurality of target SOCs from the first SOC-OCV mapping relation, wherein the target SOCs can be configured into SOCs which are arranged at intervals of x%, x is more than or equal to 1 and less than or equal to 10, and calibrating target OCVs corresponding to the target SOCs to obtain target OCV calibration values;

wherein the target OCV may be configured as an OCV corresponding to the target SOC based on experimental data.

Here, the target SOC may be preset. For example, the target SOC may be 0%,5%,10%, …,95%,100%. It is understood that the target SOC may also be set at 4% intervals, i.e., 4%,8%,12%,16%, …,96%,100%. The specific arrangement mode of the target SOC is not limited in the present application.

Specifically, based on the plurality of target SOCs and their respective corresponding target OCV calibration values, a calibrated first SOC-OCV mapping relationship may be determined.

In this way, by calibrating the target OCV corresponding to each of the plurality of target SOCs, the target OCV calibration value may be determined, and then the calibrated first SOC-OCV mapping relationship may be determined based on the plurality of target SOCs and the target OCV calibration value, so that the calibrated first SOC-OCV mapping relationship may be more accurate.

In some embodiments, the first SOC may be plural, and in order to accurately calibrate the OCV corresponding to the target SOC, the calibrating the target OCV corresponding to the target SOC to obtain the target OCV calibration value may include:

determining a first SOC having the smallest absolute value of a difference from a target SOC from among a plurality of first SOCs, and a first calibration OCV corresponding to the first SOC;

calculating a first OCV difference value, wherein the first OCV difference value is the difference value between the first calibration OCV and the first OCV;

calculating a target first OCV calibration value based on the first OCV difference value;

the target OCV calibration value is calculated based on the target OCV corresponding to the target SOC and the first OCV calibration value.

Specifically, a target OCV corresponding to the target SOC may be determined based on the experimental data.

For example, if the target SOC is 5%, then based on the first SOC-OCV map, an OCV corresponding to an SOC of 5% may be determined as the target OCV.

Then, the difference between the first calibration OCV and the first OCV is calculated to obtain a first OCV difference value, a target first OCV calibration value is calculated based on the first OCV difference value, and a target OCV calibration value corresponding to the target SOC is calculated based on the target OCV corresponding to the target SOC and the first OCV calibration value.

For example, the calculation formula of the first OCV difference value may be:

DeltaOCV(SOC)＝OCVTable(SOC)-OCVTest(SOC)

the DeltaOCV (SOC) is a first OCV difference value, the OCVTable (SOC) is a first calibration OCV corresponding to the target SOC, and the OCVTest (SOC) is the first OCV.

The calculation formula of the target OCV calibration value may be:

NewOCV(SOC)＝OCVTable(SOC)+OCVcorrect(SOC)

the new OCV (SOC) is a target OCV calibration value, the OCVTable (SOC) is a first calibration OCV corresponding to the target SOC, and the OCVcorrect (SOC) is a first OCV calibration value.

In this way, the first OCV difference may be calculated based on the first calibration OCV and the first OCV corresponding to the first SOC closest to the target SOC, and then the target OCV calibration value corresponding to the target SOC may be gradually calculated, so as to accurately calibrate the OCV corresponding to the target SOC.

As one example, the battery pack is charged or discharged from the second SOC to the first SOC, which may be plural, and exemplary, the first SOC is 3.2%,5.9%,8.5%,12.6%, … …. When the target OCV with the target SOC of 5% is to be calibrated, a first SOC with the minimum absolute value of the difference value with the target SOC is firstly taken, the first SOC which can be used for calibration is 5.9%, then a first calibration OCV corresponding to the SOC of 5.9% is searched according to experimental data, and the DeltaOCV (SOC) is the difference value between the first calibration OCV and the first OCV acquired by the battery pack meeting the first condition.

In some embodiments, to calibrate the SOC-OCV mapping relationship more accurately, the calculating the target first OCV calibration value based on the first OCV difference value may include:

calculating a target first OCV calibration value based on the first OCV difference value, the voltage sampling error coefficient, the current sampling error coefficient and the standing time length error coefficient;

wherein the voltage sampling error coefficient is configured to be associated with an error of the voltage sampling chip;

the current sampling error coefficient is configured as a function of an error associated with the current sampling chip, the second time threshold, a nominal capacity of the battery pack, and a throughput capacity of the battery pack;

the rest duration error coefficient is configured to be associated with a first time and a first time threshold that is a function of a maximum time for which the battery pack is stationary to satisfy the first condition.

For example, the calculation formula of the target first OCV calibration value may be:

OCVcorrect(SOC)＝Alpha_correct*DeltaOCV(SOC)

wherein OCVcorrect (SOC) is the target first OCV calibration value, alpha_correction is the calibration coefficient, and DeltaOCV (SOC) is the first OCV difference.

Alpha_correction=voltage sampling error coefficient current sampling error coefficient standing time error coefficient.

Wherein, voltage sampling error coefficient= (DeltaOCV (SOC) -sampling error of voltage sampling chip)/sampling error of voltage sampling chip, current sampling error coefficient = current sampling error coefficient 1 current sampling error coefficient 2. The rest duration error coefficient= |first time-first time threshold|/first time threshold.

Current sampling error coefficient 1= (1-current sampling accuracy) × (72-t 1)/72. Current sampling error coefficient 2= (2×capstd-Q)/2×capstd.

Wherein t1 is the time from the SOC calibration to the first OCV calibration, i.e., the sum of the time elapsed from the charging or discharging of the battery pack from the second SOC to the first SOC and the first time the battery pack is stationary, and Q is the discharge throughput from the SOC calibration to the first OCV calibration.

Therefore, the target first OCV calibration value corresponding to the target SOC can be more accurately determined through the first OCV difference value, the voltage sampling error coefficient, the current sampling error coefficient and the standing time length error coefficient, so that the SOC-OCV mapping relation can be more accurately calibrated.

And calculating the target OCV calibration value based on the target OCV corresponding to the target SOC and the first OCV calibration value, wherein the target OCV calibration value is calculated and is equal to target OCV+ OCVcorrect (SOC).

In some embodiments, to calibrate the SOC-OCV mapping relationship more efficiently, the target OCV calibration value may be an OCV obtained after the battery pack is calibrated in the first state, and the method may further include:

calibrating the SOC-OCV mapping relation of the battery pack in the second state based on the target OCV calibration value;

the first state is one of a charging state and a discharging state of the battery pack, and the second state is the other of the charging state and the discharging state of the battery pack.

Here, the SOC-OCV map in the discharged state may be calibrated based on the target OCV calibration value in the charged state, or the SOC-OCV map in the charged state may be calibrated based on the target OCV calibration value in the discharged state.

In this way, since the SOC-OCV map in the discharged state can be calibrated based on the target OCV calibration value in the charged state, or the SOC-OCV map in the charged state can be calibrated based on the target OCV calibration value in the discharged state, the calibration efficiency can be improved.

In some embodiments, to further improve accuracy of the SOC-OCV mapping relationship, the calibrating the OSC-OCV mapping relationship of the battery pack in the second state based on the target OCV calibration value may include:

Determining a third SOC of the battery pack in the second state, the third SOC corresponding to a target SOC of the battery pack in the first state;

determining a third OCV corresponding to the third SOC based on the experimental data;

calculating the difference value between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N difference values, and calculating the average value of the N difference values to obtain deviation;

based on the deviation and the third OCV, the SOC-OCV map of the battery pack in the second state is calibrated.

Here, the third SOC is equal to the target SOC. The number of third SOCs and the target SOCs may each be N, where N is a positive integer.

Illustratively, if the target SOC is 5%, 10%, and 15%, the target OCV calibration values corresponding to the target SOC are NewOCV (5%), newOCV (10%), and NewOCV (15%), respectively, the third SOC is 5%, 10%, and 15%, and based on experimental data, the third OCV corresponding to the third SOC is OCVTable (5%), OCVTable (10%), and OCVTable (15%), respectively, then the 3 differences are NewOCV (5%) -OCVTable (5%), newOCV (10%) -OCVTable (10%), and NewOCV (15%) -OCVTable (15%), respectively, and the deviation is the average of the above 3 differences.

The SOC-OCV mapping relationship of the calibration battery pack in the second state may be a third SOC to which the plurality of third SOCs respectively correspond, and specifically, a sum of the third OCV and the deviation may be determined as a calibrated OCV to which the third SOC corresponds.

In this way, the SOC-OCV mapping relationship is calibrated based on the difference relationship between the charged OCV and the discharged OCV, so that the accuracy of calibrating the SOC-OCV mapping relationship in the discharged state based on the target OCV calibration value in the charged state or calibrating the SOC-OCV mapping relationship in the charged state based on the target OCV calibration value in the discharged state can be improved.

Based on the same inventive concept, the embodiment of the application also provides a device for calibrating the mapping relation of SOC-OCV. The SOC-OCV map calibration apparatus according to the embodiment of the present application is described in detail below with reference to fig. 3.

Fig. 3 is a schematic structural diagram of an SOC-OCV mapping relation calibration apparatus according to an embodiment of the present application.

As shown in fig. 3, the SOC-OCV map calibration apparatus may include:

a receiving module 301, configured to receive a first state of charge SOC and a first number of cycles of the battery pack;

an acquiring module 302, configured to acquire a first open circuit voltage OCV corresponding to a first SOC;

a first determining module 303, configured to determine a first SOC-OCV mapping relationship corresponding to the first cycle number based on preset experimental data; experimental data is configured as a function between cycle number, OCV and SOC;

A second determining module 304, configured to determine a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship;

the first calibration module 305 is configured to calibrate the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV.

In some embodiments, to obtain a more accurate first OCV, the acquisition module 302 may include:

an acquisition sub-module for acquiring a second OCV of the battery pack in response to the battery pack satisfying a first condition;

the second OCV is configured as an OCV of the battery pack after the battery pack is left standing for a first time;

the first condition is configured such that, during a second time, a throughput capacity of the battery pack is less than a nominal capacity of the battery pack;

a processing sub-module configured to take the second OCV as the first OCV;

wherein the second time is configured as a time elapsed from the charging or discharging of the battery pack from the second SOC to the first SOC, and the second time is less than a second time threshold;

the throughput capacity of the battery pack is configured to be a sum of a charge accumulated capacity and a discharge accumulated capacity of the battery pack during the second time;

the second SOC is configured as a calibrated SOC.

In some embodiments, to improve accuracy of the SOC-OCV mapping, the second SOC is calibrated by one of the following calibration terms:

i) Responding to the charge or discharge of any battery cell of the battery pack to a first SOC range, standing for a third time, obtaining the current OCV of the battery pack, and calibrating to obtain the second SOC based on the current OCV and the experimental data;

ii) when the battery pack is charged, the voltage of any one of the battery cells is larger than the charging cut-off voltage and the charging current is smaller than a first current threshold value, and the time of T1 is continued, and the second SOC is calibrated to be 100%;

iii) And when the battery pack is discharged, the voltage of any battery cell is smaller than the discharge cut-off voltage, the discharge current is smaller than a second current threshold value, and the second SOC is calibrated to be 0% after the time of T2.

In some embodiments, to calibrate the SOC more accurately, the difference between different SOCs corresponding to the same OCV is less than a preset threshold value at different cycles within the first SOC range.

In some embodiments, to more accurately calibrate the SOC-OCV mapping, the first calibration module 305 may include:

the first calibration sub-module is used for determining a plurality of target SOCs from a first SOC-OCV mapping relation, wherein the target SOCs are configured as SOCs which are arranged at intervals of x percent, x is more than or equal to 1 and less than or equal to 10, and target OCVs corresponding to the target SOCs are calibrated to obtain target OCV calibration values;

wherein the target OCV is configured as an OCV corresponding to the target SOC based on the experimental data.

In some embodiments, the first SOC is a plurality; in order to accurately calibrate the OCV corresponding to the target SOC, the first calibration sub-module may include:

A determination unit configured to determine a first SOC, from among a plurality of the first SOCs, at which an absolute value of a difference from the target SOC is smallest, and a first calibration OCV corresponding to the first SOC;

the first calculating unit is used for calculating a first OCV difference value, wherein the first OCV difference value is the difference value between the first calibration OCV and the first OCV;

the second calculating unit is used for calculating a target first OCV calibration value based on the first OCV difference value;

and a third calculation unit, configured to calculate the target OCV calibration value based on the target OCV corresponding to the target SOC and the first OCV calibration value.

In some embodiments, to calibrate the SOC-OCV map more accurately, the second calculation unit may include:

a calculating subunit, configured to calculate a target first OCV calibration value based on the first OCV difference, the voltage sampling error coefficient, the current sampling error coefficient, and the standing duration error coefficient;

wherein the voltage sampling error coefficient is configured to be associated with an error of a voltage sampling chip;

the current sampling error coefficient is configured as a function of an error associated with a current sampling chip, the second time threshold, a nominal capacity of the battery pack, and a throughput capacity of the battery pack;

The resting duration error coefficient is configured to be associated with the first time and a first time threshold that is a function of a maximum time for which the battery pack meets a first condition to rest.

In some embodiments, the target OCV calibration value is an OCV of the battery pack after calibration in the first state; in order to calibrate the SOC-OCV mapping relation more efficiently, the apparatus may further include:

a second calibration module for calibrating the SOC-OCV mapping relationship of the battery pack in a second state based on the target OCV calibration value;

wherein the first state is one of a charge state or a discharge state of the battery pack, and the second state is the other of the charge state or the discharge state of the battery pack.

In some embodiments, to further improve accuracy of the SOC-OCV mapping relationship, the second calibration module may include:

a first determination sub-module for determining a third SOC of the battery pack in a second state, the third SOC corresponding to the target SOC of the battery pack in the first state;

a second determination sub-module for determining a third OCV corresponding to the third SOC based on the experimental data;

The calculating sub-module is used for calculating the difference value between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N difference values, and calculating the average value of the N difference values to obtain deviation;

and a second calibration sub-module for calibrating the SOC-OCV mapping relation of the battery pack in the second state based on the deviation and the third OCV.

Fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

As shown in fig. 4, the electronic device 4 is capable of implementing a structure diagram of an exemplary hardware architecture of the electronic device according to the SOC-OCV map calibration method and the SOC-OCV map calibration apparatus in the embodiment of the present application. The electronic device may refer to an electronic device in an embodiment of the present application.

The electronic device 4 may comprise a processor 401 and a memory 402 in which computer program instructions are stored.

In particular, the processor 401 described above may include a Central Processing Unit (CPU), or an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), or may be configured as one or more integrated circuits implementing embodiments of the present application.

Memory 402 may include mass storage for data or instructions. By way of example, and not limitation, memory 402 may comprise a Hard Disk Drive (HDD), floppy Disk Drive, flash memory, optical Disk, magneto-optical Disk, magnetic tape, or universal serial bus (Universal Serial Bus, USB) Drive, or a combination of two or more of the foregoing. Memory 402 may include removable or non-removable (or fixed) media, where appropriate. Memory 402 may be internal or external to the integrated gateway disaster recovery device, where appropriate. In a particular embodiment, the memory 402 is a non-volatile solid state memory. In particular embodiments, memory 402 may include Read Only Memory (ROM), random Access Memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical/tangible memory storage devices. Thus, in general, memory 402 includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software comprising computer-executable instructions and when the software is executed (e.g., by one or more processors) it is operable to perform the operations described with reference to a method in accordance with an aspect of the application.

The processor 401 reads and executes the computer program instructions stored in the memory 402 to implement any one of the SOC-OCV map calibration methods of the above embodiments.

In one example, the electronic device may also include a communication interface 403 and a bus 404. As shown in fig. 4, the processor 401, the memory 402, and the communication interface 403 are connected to each other by a bus 404 and perform communication with each other.

The communication interface 403 is mainly used to implement communication between each module, device, unit and/or apparatus in the embodiment of the present application.

Bus 404 includes hardware, software, or both, that couple components of the electronic device to one another. By way of example, and not limitation, the buses may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an infiniband interconnect, a Low Pin Count (LPC) bus, a memory bus, a micro channel architecture (MCa) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a video electronics standards association local (VLB) bus, or other suitable bus, or a combination of two or more of the above. Bus 404 may include one or more buses, where appropriate. Although embodiments of the application have been described and illustrated with respect to a particular bus, the application contemplates any suitable bus or interconnect.

The electronic device can execute the SOC-OCV mapping relation calibration method in the embodiment of the application, so that the SOC-OCV mapping relation calibration method and the device described in connection with figures 1 to 3 are realized.

In addition, in combination with the SOC-OCV mapping relation calibration method in the above embodiment, the embodiment of the present application may be implemented by providing a computer storage medium. The computer storage medium has stored thereon computer program instructions; the computer program instructions, when executed by a processor, implement any of the SOC-OCV map calibration methods of the embodiments described above.

It should be understood that the application is not limited to the particular arrangements and instrumentality described above and shown in the drawings. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method processes of the present application are not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between steps, after appreciating the spirit of the present application.

The functional blocks shown in the above-described structural block diagrams may be implemented in hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, a plug-in, a function card, or the like. When implemented in software, the elements of the application are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transfer information. Examples of machine-readable media include electronic circuitry, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio Frequency (RF) links, and the like. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

It should also be noted that the exemplary embodiments mentioned in this disclosure describe some methods or systems based on a series of steps or devices. However, the present application is not limited to the order of the above-described steps, that is, the steps may be performed in the order mentioned in the embodiments, or may be performed in a different order from the order in the embodiments, or several steps may be performed simultaneously.

Aspects of the present application are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions/acts specified in the flowchart and/or block diagram block or blocks. Such a processor may be, but is not limited to being, a general purpose processor, a special purpose processor, an application specific processor, or a field programmable logic circuit. It will also be understood that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware which performs the specified functions or acts, or combinations of special purpose hardware and computer instructions.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application, and in particular, the technical features set forth in the various embodiments may be combined in any manner so long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. The SOC-OCV mapping relation calibration method is characterized by comprising the following steps of:

receiving a first state of charge, SOC, and a first number of cycles of the battery pack;

acquiring a first Open Circuit Voltage (OCV) corresponding to the first SOC;

determining a first SOC-OCV mapping relation corresponding to the first cycle number based on preset experimental data; the experimental data is configured as a function between cycle number, OCV and SOC;

determining a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship;

the first SOC-OCV map is calibrated based on the first SOC, the first OCV, and the first calibrated OCV.

2. The method of claim 1, wherein the obtaining a first OCV corresponding to the first SOC comprises:

Responsive to the battery pack satisfying a first condition, collecting a second OCV of the battery pack;

taking the second OCV as the first OCV;

the second SOC is configured as a calibrated SOC.

3. The method of claim 2, wherein the second SOC is calibrated by one of the following calibration terms:

4. The method of claim 3, wherein the difference between different SOCs corresponding to the same OCV at different cycles is less than a preset threshold within the first SOC range.

5. The method of any one of claims 1 to 4, wherein the calibrating the first SOC-OCV map based on the first SOC, the first OCV, the first calibrated OCV, comprises:

determining a plurality of target SOCs from a first SOC-OCV mapping relation, wherein the target SOCs are configured to SOCs which are arranged at intervals of x%, x is more than or equal to 1 and less than or equal to 10, and calibrating target OCVs corresponding to the target SOCs to obtain target OCV calibration values;

wherein the target OCV is configured to acquire an OCV corresponding to the target SOC based on the experimental data.

6. The method of claim 5, wherein the first SOC is a plurality of;

the calibrating the target OCV corresponding to the target SOC to obtain a target OCV calibration value comprises the following steps:

determining a first SOC having a smallest absolute value of a difference from the target SOC, and a first calibration OCV corresponding to the first SOC, from among the plurality of first SOCs;

and calculating the target OCV calibration value based on the target OCV corresponding to the target SOC and the first OCV calibration value.

7. The method of claim 6, wherein calculating a target first OCV calibration value based on the first OCV difference value comprises:

8. The method of claim 6 or 7, the target OCV calibration value being an OCV of the battery pack after calibration in the first state;

the method further comprises the steps of:

calibrating an SOC-OCV mapping relation of the battery pack in a second state based on the target OCV calibration value;

9. The method of claim 8, the calibrating the OSC-OCV map of the battery pack in a second state based on the target OCV calibration value, comprising:

determining a third SOC of the battery pack in a second state, the third SOC corresponding to the target SOC of the battery pack in the first state;

calculating the difference value between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N difference values, and calculating the average value of the N difference values to obtain a deviation;

and calibrating the SOC-OCV mapping relation of the battery pack in the second state based on the deviation and the third OCV.

10. An SOC-OCV map calibration apparatus, the apparatus comprising:

the receiving module is used for receiving the first state of charge (SOC) and the first cycle times of the battery pack;

an acquisition module, configured to acquire a first open-circuit voltage OCV corresponding to the first SOC;

the first determining module is used for determining a first SOC-OCV mapping relation corresponding to the first cycle times based on preset experimental data; the experimental data is configured as a function between cycle number, OCV and SOC;

the second determining module is used for determining a first calibration OCV corresponding to the first SOC based on the first SOC-OCV mapping relation;

and the first calibration module is used for calibrating the first SOC-OCV mapping relation based on the first SOC, the first OCV and the first calibration OCV.

11. An electronic device, the device comprising: a processor and a memory storing computer program instructions;

the processor, when executing the computer program instructions, implements the SOC-OCV map calibration method as recited in any one of claims 1-9.

12. A computer storage medium having stored thereon computer program instructions which, when executed by a processor, implement the SOC-OCV mapping relation calibration method of any one of claims 1-9.

13. A computer program product, characterized in that instructions in the computer program product, when executed by a processor of an electronic device, cause the electronic device to perform the SOC-OCV mapping relation calibration method of any of claims 1-9.