CN116190836A

CN116190836A - SOC correction method, battery module and electronic equipment

Info

Publication number: CN116190836A
Application number: CN202310287778.4A
Authority: CN
Inventors: 吴东; 陈熙; 王雷; 罗文强
Original assignee: Ecoflow Technology Ltd
Current assignee: Ecoflow Technology Ltd
Priority date: 2023-03-15
Filing date: 2023-03-15
Publication date: 2023-05-30

Abstract

The application provides an SOC correction method, a battery module and electronic equipment. The SOC correction method comprises the steps of obtaining charging parameters of a battery in each operation period, wherein the charging parameters comprise display SOC and battery voltage; when the charging parameters of the battery meet preset conditions, determining a target SOC of the battery; determining an SOC correction coefficient according to the target SOC and the display SOC; and updating the display SOC according to the SOC correction coefficient, and displaying the updated display SOC. The SOC correction method provided by the application can effectively improve the SOC display precision of the battery.

Description

SOC correction method, battery module and electronic equipment

Technical Field

The application relates to the technical field of batteries, in particular to an SOC correction method, a battery module and electronic equipment.

Background

The State of Charge (SOC) of a battery is an important parameter describing the operating State of the battery, and is expressed as a ratio of the remaining battery power to the actual battery capacity. The user can judge the residual electric quantity of the energy storage product or the electronic product through the SOC. However, the existing SOC calculation method has a certain error, particularly at the end of charge and discharge, the SOC error is amplified, abrupt change or long-time invariance of the SOC is easily caused, the accuracy is low, and the user experience is greatly reduced.

Disclosure of Invention

In view of the above, the present application provides an SOC correction method, a storage medium, a control circuit, and an electronic apparatus to solve the above-mentioned problems.

A first aspect of the present application provides an SOC correction method, including: acquiring charging parameters of the battery in each operation period, wherein the charging parameters comprise display SOC and battery voltage; when the charging parameters of the battery meet preset conditions, determining a target SOC of the battery; determining an SOC correction coefficient according to the target SOC and the display SOC; and updating the display SOC according to the SOC correction coefficient, and displaying the updated display SOC. According to the scheme, the charging parameters of the battery are obtained in each operation period, after the charging parameters of the battery meet the preset conditions, a target SOC which is similar to the actual SOC of the battery is determined, so that the corresponding SOC correction coefficient is determined according to the target SOC, and the display SOC is updated through the SOC correction coefficient, so that the display SOC change trend of the battery is enabled to follow the actual SOC change. Therefore, the SOC correction method can enable the corrected SOC change to be more in line with the actual SOC change trend, so that the phenomenon of abrupt change or long-time invariance of the SOC at the charging terminal is avoided, and the SOC display precision of the battery is effectively improved.

In one embodiment, determining the target SOC of the battery when the charging parameter of the battery satisfies a preset condition includes: and when the display SOC is greater than or equal to the preset SOC and the battery voltage is less than the first voltage threshold, determining the preset SOC as the target SOC.

In one embodiment, the SOC correction method further includes: determining a charging mode of the battery; and determining a preset SOC and a first voltage threshold corresponding to the preset SOC according to the charging mode.

In one embodiment, determining the target SOC of the battery when the charging parameter of the battery satisfies a preset condition includes: when the battery voltage is greater than or equal to the first voltage threshold, a target SOC of the battery is determined based on the battery voltage and a charging mode of the battery.

In one embodiment, determining a target SOC of a battery from a battery voltage and a charging mode of the battery includes: when the charging mode is a first charging mode, acquiring charging current of the battery; determining a target SOC according to the charging current and the battery voltage; or when the charging mode is the second charging mode, determining a target SOC according to the battery voltage and a preset mapping relation; the charging current in the first charging mode is greater than the charging current in the second charging mode.

In one embodiment, determining the SOC correction factors based on the target SOC and the display SOC includes: calculating a difference value between the target SOC and the display SOC to obtain a first SOC difference value; calculating the difference value between the SOC when the battery is full and the target SOC to obtain a second SOC difference value; determining an adjustment step length according to the first SOC difference value and the second SOC difference value; wherein, the adjusting step length and the first SOC difference value form a positive correlation, and the adjusting step length and the second SOC difference value form a negative correlation; and calculating the sum of the initial correction coefficient and the adjustment step length to obtain the SOC correction coefficient.

In one embodiment, updating the display SOC according to the SOC correction coefficient includes: calculating the SOC variation of the battery in the running period; determining a target SOC variation according to the SOC correction coefficient and the SOC variation; and updating the display SOC according to the target SOC variation.

In one embodiment, the SOC correction method further includes: limiting the display SOC to be not more than a preset SOC threshold when the battery voltage is less than a second voltage threshold; or updating the display SOC to the SOC at which the battery is full when the battery voltage is greater than or equal to the second voltage threshold; wherein the preset SOC threshold is less than the SOC at which the battery is full.

A second aspect of the present application provides a battery module comprising a battery, a processor, and a memory, the memory comprising one or more computer instructions. One or more computer instructions are executed by a processor to implement the SOC correction method as recited in any of the preceding claims.

A third aspect of the present application provides an electronic device comprising a battery module as described above.

According to the SOC correction method, after the charging parameters of the battery meet preset conditions, the target SOC close to the actual SOC is introduced, so that the corresponding SOC correction coefficient is determined according to the target SOC, and the display SOC is updated through the SOC correction coefficient, so that the display SOC change trend of the battery is enabled to follow the actual SOC change. Therefore, the SOC correction method can enable the corrected SOC change to be more in line with the actual SOC change trend, so that the phenomenon of abrupt change or long-time invariance of the SOC at the charging terminal is avoided, and the SOC display precision of the battery is effectively improved.

Drawings

Fig. 1 is a schematic diagram showing the SOC of a conventional battery.

Fig. 2 is a schematic diagram showing the SOC of another conventional battery.

Fig. 3 is a block diagram illustrating a battery module to which the SOC correction method of the present application is applied.

Fig. 4 is a flowchart of an SOC correction method according to an embodiment of the present application.

Fig. 5 is a flowchart illustrating specific steps of step S430 shown in fig. 4 according to an embodiment of the present application.

Fig. 6 is a flowchart illustrating specific steps of step S440 shown in fig. 4 according to an embodiment of the present application.

Fig. 7a is a schematic diagram of SOC curves before and after the battery in the fast charge mode is applied to the SOC correction method according to an embodiment of the present application.

Fig. 7b is a schematic diagram of SOC curves before and after the battery in the slow charge mode is applied to the SOC correction method according to an embodiment of the present application.

Fig. 7c is a schematic diagram of SOC curves before and after the SOC correction method according to an embodiment of the present application is applied to the battery in the low-current charging mode.

Fig. 8a is a graph showing the change of the voltage of the battery charged in the fast charge mode with time.

Fig. 8b is a graph showing the change of the charging current with time in the fast charging mode.

Fig. 9 is a graph showing the change of the voltage of the charged battery with time in the small current mode.

Fig. 10a is a schematic diagram of SOC curves before and after a battery in a fast charge mode is applied to an SOC correction method according to another embodiment of the present application.

Fig. 10b is a schematic diagram of SOC curves before and after the battery in the slow charge mode is applied to the SOC correction method according to another embodiment of the present application.

Fig. 10c is a schematic diagram of SOC curves before and after the battery in the low current mode is applied to the SOC correction method according to another embodiment of the present application.

Fig. 11 is a functional block diagram of a battery module according to an embodiment of the present application.

Fig. 12 is a block diagram of an electronic device according to an embodiment of the present application.

Description of the main reference signs

10-Battery Module 11-Battery management System, BMS 12-Battery

121-cell 13-processor 14-memory

1-electronic device

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments. The following embodiments and features of the embodiments may be combined with each other without conflict.

The flow diagrams depicted in the figures are merely illustrative and not necessarily all of the elements and operations/steps are included or performed in the order described. For example, some operations/steps may be further divided, combined, or partially combined, some of the steps may be deleted, and thus the order of actual execution may be changed according to actual situations.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It should be noted that the terms "first" and "second" in the specification, claims and drawings of this application are used for distinguishing between similar objects and not for describing a particular sequential or chronological order.

The State of Charge (SOC) of a battery is an important parameter describing the operating State of the battery, and is expressed as a ratio of the remaining battery power to the actual battery capacity. The user can judge the residual electric quantity of the energy storage product or the electronic product by displaying the SOC. However, the existing display SOC calculation method has certain errors, particularly at the charge and discharge end, the SOC errors are amplified, abrupt change or long-time invariance of the display SOC is easy to cause, the accuracy is low, and the user experience is greatly reduced.

For example, in the fast charge mode or the slow charge mode, the display SOC of the charge end stagnates at 99% for a long time. Referring to fig. 1, fig. 1 is a schematic diagram showing the increase of SOC with time in the fast charge mode. As can be seen from fig. 1, in the fast charge mode, the increasing trend of the SOC from 0 to 99% is stable, but the charging end stays at 99% for a long time, for example, the SOC shown at the point a and the point b in fig. 1 is 99%, but stagnates for about 41 minutes. When the slow charge mode is used for charging, there is also a phenomenon that the SOC stagnates at 99% for a long period of time.

For another example, in the small current mode, the display SOC at the end of charge is abrupt. Referring to fig. 2, fig. 2 is a graph showing the increase of SOC with time during battery charging in a low current mode (charging current between 1.2A and 3A). As can be seen from fig. 2, in the low current mode, it is shown that SOC increases to 93% (see point c of fig. 2) and then increases to 100% (see point d of fig. 2) at a rapid rate within 5 seconds.

Therefore, the application provides an SOC correction method, a battery module and electronic equipment, so that the display accuracy of the display SOC of a battery is improved. These embodiments will be described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

Referring first to fig. 3, fig. 3 is a schematic diagram of an implementation environment according to the present application. The battery module 10 is taken as an example of the implementation environment. In fig. 3, the battery module 10 includes a battery management system (Battery Manatement System, BMS) 11 and a battery 12. The battery management system 11 is used to control the charging and discharging of the battery 12. The battery 12 includes at least one cell 121. In the example shown in fig. 3, the battery management system 11 in the battery module 10 is also used to make SOC corrections to the battery 12 of the battery module 10. That is, the SOC correction method provided by the present application is executed by the battery management system 11. Further, it may be executed by a processor (not shown in the figure) loaded with the battery management system 11.

It is understood that, in some embodiments, the battery management system 11 may also be configured outside the battery module 10, for example, loaded on another processor independent of the battery module 10, and then the SOC correction method of the present application is executed by the other processor independent of the battery module 10.

Fig. 4 is a flowchart of an SOC correction method according to an embodiment of the present application. The SOC correction method comprises the following steps:

step S410: at each operating cycle, a charging parameter of the battery is obtained, the charging parameter including a display SOC and battery voltage.

In step S410, the operation cycle may be an operation cycle of the controller, and during the operation cycle, the controller acquires battery parameters to perform the SOC correction method. That is, the controller periodically executes the SOC correction method and updates the display SOC at each operation cycle. In this way, a timed refresh of the display SOC of the battery can be achieved, the refresh frequency of which depends on the operating period of the controller, when the operating period is extremely small, the display SOC approaches the real-time SOC.

In this embodiment, the display SOC may be calculated from the capacity information of the battery. The manner of calculating the display SOC may be different, for example, the display SOC may be calculated by an ampere-hour integration method, or the display SOC may be calculated based on an extended kalman filter (Extended Kalman Filter, EKF), which is not limited in this application, and in other embodiments, the display SOC may be calculated by other manners. It will be appreciated that the battery management system 11 may retrieve the currently calculated display SOC directly from memory or registers. However, as shown in fig. 1 and 2, the existing SOC calculation method has a certain error, especially the SOC error at the charge and discharge end is amplified, and the accuracy is low. In this way, the display SOC acquired in step S410 has a certain error, and is not necessarily the actual SOC of the battery.

In this embodiment, the battery management system 11 may acquire parameters of the battery through the front-end analog chip to acquire the battery voltage. It is understood that the manner of obtaining the charging parameters of the battery may be set according to actual requirements, which is not limited in this application.

Step S420: when the charging parameter of the battery meets the preset condition, determining the target SOC of the battery.

In step S420, the preset condition refers to a condition that triggers the SOC correction method. Thus, when the charging parameters of the battery meet the preset conditions, the current display SOC has a large error, and at the moment, the controller triggers the SOC correction method and acquires the target SOC of the battery.

In step S420, the target SOC is an SOC value that approaches the actual SOC of the battery when the charging parameter of the battery satisfies a preset condition. The battery parameters include the display SOC and the battery voltage, so in step S420, the target SOC may be determined when the display SOC and the battery voltage satisfy the predetermined conditions.

Specifically, in some embodiments, a lookup table may be established for displaying the SOC, the battery voltage, and the target SOC. Thus, in step S420, after the display SOC and the battery voltage are obtained, a lookup operation may be performed to determine the target SOC. In other embodiments, the battery module 10 may further include a memory in which a functional relation for displaying the SOC, the battery voltage, and the target SOC may be stored. In this way, in step S420, the target SOC can be calculated from the functional relation after the display SOC and the battery voltage are acquired. The lookup table and the functional relation can be obtained based on a plurality of groups of test data about the battery module in a laboratory.

As can be appreciated, existing SOC correction methods typically trigger SOC correction by the voltage of the battery. However, taking the example of the battery being in the fast charge mode or the slow charge mode, there is a constant voltage charging phase during the battery charging process. Thus, when the SOC is virtually high (i.e., the SOC is shown to be greater than the actual SOC) and the battery is in a constant voltage charging stage (the battery voltage is unchanged), even if the battery voltage does not reach a voltage value that triggers the SOC correction, there is a possibility that the battery SOC as shown in fig. 1 stagnates for a long period of time at 99%. When the battery SOC is virtually low (i.e., the SOC is shown to be less than the actual SOC), the battery voltage may correct the battery SOC at the instant when the voltage value triggering the SOC correction is reached, thereby causing the battery SOC to suddenly increase, resulting in a battery SOC surge condition as shown in fig. 2.

In step S420 of the present application, the battery parameters include the display SOC and the battery voltage, and the SOC correction is triggered when the display SOC and the battery voltage of the battery satisfy the preset conditions. Thus, step S420 comprehensively considers two factors of the battery voltage and the display SOC, and can achieve more accurate SOC correction.

Step S430: and determining an SOC correction coefficient according to the target SOC and the display SOC.

In step S430, the correction coefficient is related to the target SOC and the display SOC. And the SOC correction coefficient is used to characterize the difference between the displayed SOC and the target SOC during the run period, i.e., the SOC correction coefficient is used to characterize the difference between the displayed SOC and the actual SOC during the run period. When the absolute value of the SOC correction coefficient is larger, the current display SOC deviates from the actual SOC by a larger degree, and the correction rate is faster; when the absolute value of the SOC correction coefficient is smaller, the degree of deviation of the current display SOC from the actual SOC is smaller, and the correction rate is smaller.

Step S440: and updating the display SOC according to the SOC correction coefficient, and displaying the updated display SOC.

In step S440, the display SOC is adjusted according to the SOC correction coefficient to reduce the gap between the display SOC and the actual SOC, and the updated display SOC is displayed. In this way, by adjusting the display SOC according to the SOC correction coefficient determined by the target SOC, the display SOC variation trend of the battery can be made to follow the target SOC variation, i.e., the display SOC variation of the battery is made to more conform to the actual SOC variation trend.

It can be understood that in the SOC correction method provided by the present application, by acquiring the charging parameter of the battery, and introducing the target SOC close to the actual SOC when the charging parameter of the battery meets the preset condition, so as to determine the SOC correction coefficient according to the display SOC and the target SOC, so that the display SOC is updated according to the SOC correction coefficient, so that the display SOC variation trend of the battery follows the actual SOC variation. Therefore, the SOC correction method can enable the corrected SOC change to be more in line with the actual SOC change trend, so that the SOC mutation at the charging terminal is reduced or the SOC is unchanged for a long time, and the SOC display precision of the battery is effectively improved.

Further, the charging parameters include a display SOC and a battery voltage, and compared with the existing method for triggering SOC correction based on the battery voltage only, the battery voltage and the display SOC can be comprehensively considered, so that more accurate SOC correction is realized.

It can be understood that, after step S410 is performed, when there is an error in the display SOC obtained in step S410, the obtained display SOC may have a virtual high or a virtual low. The following embodiments of the present application continue to describe a specific working process of the SOC correction method provided by the present application with two obtained scenes of displaying the SOC virtual high trigger correction or displaying the SOC virtual low trigger correction.

First scenario: display SOC virtual high triggering SOC correction

It will be appreciated that as the charge duration increases, the display SOC and battery voltage generally increase. And the test data between the battery voltages and the corresponding actual SOCs can be obtained through multiple groups of tests performed in a laboratory in the charging process. And the value of the minimum battery voltage corresponding to a specific actual SOC value can be determined through the plurality of groups of test data; or the maximum actual SOC corresponding to a particular battery voltage value. In this manner, it may be determined whether the acquired display SOC is virtually high based on the sets of test data.

For example, in some embodiments, step S420 may include the following step S421:

step S421: and when the display SOC is greater than or equal to the preset SOC and the battery voltage is less than the first voltage threshold, determining the preset SOC as the target SOC.

In step S421, the value of the minimum battery voltage corresponding to the preset SOC is the first voltage threshold. When the display SOC is greater than or equal to the preset SOC and the corresponding battery voltage value is greater than the first voltage threshold, the acquired display SOC is not in a virtual height. And when the display SOC is larger than or equal to the preset SOC and the corresponding battery voltage value is smaller than the first voltage threshold value, indicating that the acquired display SOC is virtually high. In this way, by comparing the obtained display SOC and the battery voltage with the preset SOC and the first voltage threshold, respectively, it is possible to confirm whether the current display SOC is virtually high.

In step S421, when it is confirmed that the display SOC is virtually high, the preset SOC is determined as the target SOC to trigger SOC correction by the preset SOC. Obviously, when the acquired display SOC is virtually high, the preset SOC is closer to the actual SOC than the acquired display SOC. In this way, by taking the preset SOC as the target SOC to participate in correcting the display SOC, the tendency of variation in the display SOC can be corrected.

Further, it is considered that when the battery has different charging modes, the preset SOC and the first voltage threshold corresponding to the different charging modes may be different. As such, in some embodiments, step S420 in the SOC correction method provided herein further includes the following steps before performing step S421:

Step S422: a charging mode of the battery is determined.

In some embodiments, the battery parameters further include a charging current. In step S422, the current battery charging mode may be determined by acquiring a charging current. For example, when a charging current between 1.2A (amperes) and 3A is detected, the battery is considered to be charged in a first charging mode; when a charging current greater than 3A is detected, the battery is considered to be charged in the second charging mode. Wherein the first charging mode may be a low current mode; the second charging mode may be a fast charging mode or a slow charging mode.

In some embodiments, the battery voltage or charging power is different for different charging modes. Thus, the lookup operation can be performed through the obtained battery voltage or charging power to determine the charging mode of the battery. The present application is not limited to a method of determining a battery charging mode, for example, in other embodiments, the battery management system 11 may also communicate with the power supply device via a charging protocol, and determine the corresponding charging mode by reading the charging setting parameters in the charging protocol.

Step S423: and determining a preset SOC and a first voltage threshold corresponding to the preset SOC according to the charging mode.

In the embodiment of the present application, when it is confirmed in step S422 that the battery is in the first charging mode, the preset SOC may be 90%, and the first voltage threshold may be 4040mV (millivolts); when it is confirmed in step S422 that the battery is in the second charge mode, the preset SOC may be 87.7%, and the first voltage threshold may be 4110mV (millivolt). For example, the first charging mode may be a fast charging mode or a slow charging mode, and the second charging mode may be a low current charging mode.

It can be appreciated that, in the embodiment of the present application, the values of the preset SOC and the first voltage threshold in step S423 can be obtained by a plurality of sets of laboratory test data. The values of the preset SOC and the first voltage threshold are not limited in this application. In other embodiments, the preset SOC and the first voltage threshold may be adjusted accordingly according to different specifications of the battery, the charging mode of the battery, and corresponding laboratory test data.

Thus, in some embodiments, the determination target SOC in step S420 may be achieved by performing step S421 (or performing step S422, step S423, and step S421) described above.

With continued reference to fig. 5, in some embodiments, after determining the target SOC, step S430 includes the steps of:

Step S510: and calculating the difference value of the target SOC and the display SOC to obtain a first SOC difference value.

For example, with the target SOC being e and the display SOC being f, the first SOC difference is e-f.

Step S520: and calculating the difference value between the SOC when the battery is full and the target SOC to obtain a second SOC difference value.

Understandably, the SOC at battery full is 100%. Thus, the second SOC difference is 100% -e.

Step S530: determining an adjustment step length according to the first SOC difference value and the second SOC difference value; the adjusting step length and the first SOC difference value form a positive correlation, and the adjusting step length and the second SOC difference value form a negative correlation.

For example, in some embodiments, the calculation formula for the adjustment step size may be:

g＝k*(e-f)/(100％-e) (1)

wherein g in the calculation formula (1) is an adjustment step length, and k is an adjustment coefficient. The adjusting coefficient is used for limiting the adjusting step length to limit the value of the adjusting step length within a proper interval range. It is understood that in other embodiments, the adjustment step may be other calculation formulas, and the application is not limited thereto, as long as the adjustment step and the first SOC difference value satisfy a positive correlation, and the adjustment step and the second SOC difference value satisfy a negative correlation.

Step S540: and calculating the sum of the initial correction coefficient and the adjustment step length to obtain the SOC correction coefficient.

In the embodiment of the present application, the initial correction coefficient is 1. Thus, the calculation formula of the SOC correction coefficient is:

m= 1+g; i.e.

m＝1+k*(e-f)/(100％-e) (2)

Wherein m in the calculation formula (2) is an SOC correction coefficient.

With continued reference to fig. 6, after obtaining the SOC correction coefficient, step S440 includes the following steps:

step S610: and calculating the SOC variation of the battery in the operation period.

In step S610, the SOC variation amount refers to the SOC variation amount of the battery in the current operation period. For example, in some embodiments, when the display SOC is calculated using the ampere-hour integration method, the SOC variation amount may be an SOC integrated value obtained by integrating calculation based on the battery capacity, the battery current, and the charge-discharge efficiency in the operation period.

Step S620: and determining a target SOC variation according to the SOC correction coefficient and the SOC variation.

In some embodiments, the calculation formula of the target SOC variation is

ΔSOC＝j*m*n+d (3)

Wherein Δsoc in the calculation formula (3) is the target SOC variation; j is a first adjustment parameter; n is the SOC variation; d is a second adjustment parameter. It is understood that the first adjustment parameter j and the second adjustment parameter d are used to jointly adjust the target SOC variation amount to clip the target SOC variation amount. Wherein j is a percentage less than or equal to 1; d is a constant and d may be a positive or negative value.

In the embodiment of the present application, the first adjustment parameter j is 1, and the second adjustment parameter d is 0. That is, in the embodiment of the present application, the target SOC variation amount is the product between the SOC correction coefficient m and the SOC variation amount n. It can be appreciated that in other embodiments, the values of the first adjustment parameter j and the second adjustment parameter d may be adjusted according to the debugging situation to obtain the target SOC variation amount.

Step S630: and updating the display SOC according to the target SOC variation.

In the embodiment of the present application, the updated display SOC is the sum of the acquired display SOC and the target SOC variation amount.

Understandably, since the adjustment step size m has a positive correlation with the first SOC difference value, the adjustment step size m has a negative correlation with the second SOC difference value, so that when the target SOC differs more from the acquired display SOC (i.e., the larger the value of e-f), the larger the absolute value of the adjustment step size is, the faster the correction rate is; when the target SOC month is close to the SOC at which the battery is full (i.e., the smaller the value of 100% -e), the larger the absolute value of the adjustment step is, the faster the correction rate is. Thus, the adjustment step length in the embodiment of the application is a dynamic value according to the change of the display SOC and the target SOC, so that the dynamic correction of the display SOC can be realized, and the adjustment precision is higher.

Understandably, when the SOC is displayed to be virtually high, then the first SOC difference value is negative. Thus, the adjustment step length calculated according to the formula is a negative number, and the SOC correction coefficient is smaller than 1, so that the target SOC variation is still a positive number, but smaller than the SOC variation, the display SOC updated according to the target SOC variation can be decelerated and increased, and the updated display SOC is more in line with the increasing trend of the actual SOC of the battery.

Understandably, when the adjustment step size is too large, the modified display SOC is easy to jump; when the adjustment step is too small, the target SOC variation is too small to quickly catch up with the variation of the actual SOC of the battery. In this way, by setting the adjustment coefficient k, the adjustment step length can be maintained within a reasonable range, and the calculated target SOC variation can better correct the difference between the display SOC and the actual SOC, so that the updated display SOC approaches to the actual SOC of the battery.

It can be understood that the value of the adjustment coefficient k is not specifically limited in this application, and the adjustment coefficient k can be adjusted accordingly according to the debugging situation.

Understandably, when the SOC correction method is executed again upon entering the next operation cycle, the display SOC acquired in step S410 is the updated display SOC. Therefore, through SOC correction of a plurality of operation periods, the development trend of the displayed SOC of the battery is similar to that of the actual SOC of the battery, the occurrence of the condition that the displayed SOC is suddenly changed or unchanged for a long time is reduced, and the SOC display precision of the battery is effectively improved.

In some embodiments, after updating the acquired display SOC, the SOC correction method provided in the present application further includes the following steps:

limiting the display SOC to be not more than a preset SOC threshold when the battery voltage is less than a second voltage threshold; or (b)

When the battery voltage is greater than or equal to the second voltage threshold, the display SOC is updated to the SOC at which the battery is full.

It will be appreciated that the second voltage threshold is the battery voltage when the battery is full, and that overvoltage protection will be triggered when the battery voltage is the second voltage threshold. That is, when the battery voltage is greater than or equal to the second voltage threshold, it is indicated that the battery is already full; when the battery voltage is less than the second voltage threshold, it is indicated that the battery is not yet full. And because the preset SOC threshold value is smaller than the SOC (100%) when the battery is full, when the battery voltage is smaller than the second voltage threshold value, the updated display SOC is limited to be smaller than or equal to the preset SOC threshold value, so that the updated display SOC is smaller than 100%, and the updated display SOC is prevented from displaying that the battery is full by mistake. When the battery voltage is greater than or equal to the second voltage threshold, the display SOC is updated to 100%, and the display SOC can be corrected in time. In some embodiments, the preset SOC threshold value is 99%.

Referring to fig. 7a, 7b and 7c, fig. 7 a-7 c are schematic diagrams of SOC curves before and after the SOC correction method in the first scenario is applied to the battery in the fast charge mode, the slow charge mode and the low current mode, respectively. The curve S1 in fig. 7a is a raw SOC curve when the battery is charged in the fast charge mode, and the curve S2 in fig. 7a is an SOC curve obtained by correcting the display SOC according to the SOC correction method provided in the above embodiment when the battery is charged in the fast charge mode. Curve S3 of fig. 7b is an SOC curve in the related art when the battery is charged in the slow charge mode, and curve S4 of fig. 7b is an SOC curve after the display SOC is corrected according to the SOC correction method provided in the above-described embodiment when the battery is charged in the slow charge mode. Curve S5 of fig. 7c is a raw SOC curve when the battery is charged in the low current mode, and curve S6 of fig. 7c is a SOC curve after the display SOC is corrected according to the SOC correction method provided in the above-described embodiment when the battery is charged in the low current mode. Obviously, according to fig. 7 a-7 c, after the SOC correction method provided by the present application is applied, the SOC abrupt change phenomenon occurring at the charging terminal can be reduced in various charging modes, and the duration of the SOC maintenance is reduced, so that the SOC variation more accords with the actual SOC variation trend, and the SOC display precision of the battery is effectively improved.

The second scenario: display SOC false low triggering SOC correction

In the second scenario, after acquiring the display SOC and the battery voltage in step S410, step S420 includes:

step S424: when the battery voltage is greater than or equal to the first voltage threshold, a target SOC of the battery is determined based on the battery voltage and a charging mode of the battery.

Similarly, based on tests performed by the laboratory between the sets of battery voltages and the actual SOC of the battery, it was confirmed that the displayed SOC of the battery is generally virtually low when the battery voltage is greater than or equal to the first voltage threshold. Thus, in step S424, when the battery voltage is greater than or equal to the first voltage threshold, it is determined that the display SOC of the battery is low. That is, when the SOC is displayed to be low, the SOC correction is triggered by the battery voltage.

It is understood that the target SOC is related to the charge mode of the battery and the battery voltage. In some embodiments, a mapping relationship between battery voltage and target SOC may be established in different charging modes based on laboratory-acquired sets of test data between battery voltage and target SOC, and a lookup table or computational function may be generated. Thus, in step S424, when the corresponding battery voltage in a certain charging mode of the battery is obtained, the processor in the battery management system 11 may perform a look-up table operation or perform calculation to confirm the corresponding target SOC, thereby correcting the display SOC.

Further, some embodiments are also provided herein for determining a target SOC of a battery based on a battery voltage and a charging mode of the battery. For example, in some embodiments, step S424 may include:

step S425: when the charging mode is a first charging mode, acquiring charging current of the battery; the target SOC is determined based on the charging current and the battery voltage.

The first charging mode may be a fast charging mode or a slow charging mode. The charging current of the battery can be obtained by the battery management system 11 through the front-end analog chip. The following description illustrates the process of determining the target SOC of the battery based on the charging current and the battery voltage, taking the first charging mode as the fast charging mode charging example.

First, a first voltage V1 and a second voltage V2 are selected (see fig. 8 a), and a first equation about the virtual correction voltage is established based on the first voltage V1 and the second voltage V2. In some embodiments, the first voltage V1 is a first voltage threshold. The first voltage threshold may be a voltage value corresponding to an actual SOC of the battery of 90%, for example 4110mV (millivolts). The second voltage V2 is the battery voltage value at which the battery enters the constant voltage charging stage during charging, for example 4175mV. In some embodiments, the second voltage V2 may also be a difference between the battery voltage value in the constant voltage charging stage and the preset voltage value, so that by subtracting the preset voltage value, the occurrence of the limit condition can be reduced, and the charging safety of the battery can be improved.

Then, first virtual voltage coordinates (V1, 4) and second virtual voltage coordinates (V2, 0) are constructed based on the first voltage V1 and the second voltage V2. Finally, a first equation for the virtual correction voltage is determined on the basis of the first virtual voltage coordinates (V1, 4) and the second virtual voltage coordinates (V2, 0):

Yvolt＝-X1/15+278

where Yvolt is the virtual correction voltage and X1 is the battery voltage value used to determine the target SOC.

Then, the first current I1 and the second current I2 are selected (see fig. 8 b), and a second equation for the virtual correction current is established based on the first current I1 and the second current I2. In some embodiments, the first current I1 is the charging current of the last constant current charging phase during battery charging, for example 16000mA (milliamp). The second current I2 is a sum of a charge cutoff current (e.g., 3000 mA) and an initial current (e.g., 1A), and thus, the second current I2 may be 4000mA. It can be understood that by adding the initial current on the basis of the cut-off current, the occurrence of the limit condition can be reduced, and the charging safety of the battery can be improved.

Then, first virtual current coordinates (I1, 5) and second virtual current coordinates (I2, 9) are constructed based on the first current I1 and the second current I2. Finally, a second equation for the virtual correction current is determined on the basis of the first virtual current coordinates (I1, 5) and the second virtual current coordinates (I2, 9):

Ycur＝-X2/3000+31/3

Where Ycur is a virtual correction current, and X2 is a charging current value for determining the target SOC.

Please refer to fig. 8a and 8b together. Fig. 8a and 8b are voltage and current curves of the same battery in the fast charge mode, respectively. As can be seen from fig. 8a and 8b, the charging current decreases as the battery voltage increases when entering the charging end of the battery. In the SOC calculation method (for example, ampere-hour integration method) that is generally used, since both the battery voltage and the charging current have an influence on the battery SOC, virtual correction points (for example, 4, 0, 5, 9, etc.) are introduced into the first virtual voltage coordinate, the second virtual voltage coordinate, the first virtual current coordinate, and the second virtual current coordinate in the process of constructing the map between both the battery voltage and the charging current and the target SOC, so that the target SOC is calculated. The virtual correction point boundary values of the voltages are 4 and 0 in the first virtual voltage coordinate and the second virtual voltage coordinate, that is, the corresponding virtual correction points may be 4, 3, 2, 1, and 0 in sequence during the voltage rising process of the charging terminal. The virtual correction point boundary values of the current are 5 and 9 in the first virtual current coordinate and the second virtual current coordinate, that is, the corresponding virtual correction points may be 5, 6, 7, 8, and 9 in sequence during the current drop of the charging end. It is understood that the virtual correction point has no specific physical meaning, and is only an intermediate quantity when calculating the map of the target SOC with the battery voltage and the charging current.

Further, the third party program is satisfied between the virtual correction point and the virtual correction voltage and the virtual correction current:

Ysoc＝Ycur–Yvolt，Ysoc∈[1,9]

finally, in fig. 8a and 8b, the voltage value and the current value corresponding to the same time point of the battery are obtained and substituted into the first to third party programs, and the actual SOC of the corresponding time point of the battery is obtained, so that a mapping relation table between the virtual correction point and the actual SOC of the battery can be obtained. For example, please refer to the following table:

mapping relation table between virtual correction point Ysoc and battery SOC

Further, the Ysoc in the table above is fitted to the target SOC to generate a corresponding fourth aspect, for example:

Tsoc＝h*Ysoc ² +i*Ysoc+p

where h= -0.02335, i=1.662, p=86.06, tsoc represents the target SOC, and Tsoc e [87.7,99]. Thus, the mapping relationship between the target SOC and the charging current and battery voltage can be established by the virtual correction point Ysoc. That is, in step S425, according to the battery voltage, the charging current, the first equation, the second equation and the third equation, the virtual correction points corresponding to the battery voltage and the charging current can be calculated; and obtaining the target SOC corresponding to the current battery voltage and charging current according to the calculated virtual correction point and the fourth program.

In other embodiments, step S424 may include:

step S426: and when the charging mode is the second charging mode, determining the target SOC according to the battery voltage and a preset mapping relation.

Wherein the second charging mode may be a low current charging mode. And the charging current in the first charging mode is greater than the charging current in the second charging mode. For example, in some embodiments, the charging current in the first charging mode is greater than 3A (amps) and the charging current in the second charging mode is greater than or equal to 1.2A and less than or equal to 3A.

Referring to fig. 9, fig. 9 is a graph showing a voltage change of the battery with an increase of the charging time in the low current mode. In the small current mode, the battery is charged without switching between a constant current stage and a constant voltage stage, that is, the current dropping process is not generated in the battery charging process in the small current mode. Therefore, the mapping relation between the battery voltage and the target SOC can be established by directly acquiring the two voltages and the corresponding SOC values of the battery in the voltage change curve in the small current mode.

For example, the third voltage V3 and the fourth voltage V4 in fig. 9 are selected. The third voltage V3 is a voltage value corresponding to the SOC of the battery being 90%, for example, 4040mV; the fourth voltage V4 is a voltage corresponding to 100% SOC of the battery, for example, 4140mV. Thus, a fifth equation representing the map between the battery voltage and the target SOC in the low-current mode can be obtained:

Tsoc＝X3/10–314

Where X3 is a battery voltage value in the small current mode, and Tsoc represents a target SOC.

Thus, in step S426, the target SOC corresponding to the battery voltage is determined according to the battery voltage and the fifth equation.

It will be appreciated that in the second scenario, steps S510-S540, and steps S610-S630 described in the first scenario may be continued to update the display SOC. That is, in the second scenario, the step S240 of acquiring the target SOC in the first scenario is replaced with the step S420 in the second scenario, so that the update of the display SOC in the second scenario can be realized.

Please continue to refer to fig. 10a, 10b and 10c. Fig. 10a, 10b and 10c are schematic diagrams of SOC curves before and after the SOC correction method in the second scenario of battery application in the fast charge mode, the slow charge mode and the low current mode, respectively. The curve S7 in fig. 10a is a display SOC curve in a related scheme during battery charging in the fast charge mode, and the curve S8 in fig. 10a is a display SOC curve after the display SOC is corrected according to the SOC correction method provided in the above embodiment during battery charging in the fast charge mode. Curve S9 of fig. 10b is a display SOC curve in the related scheme when the battery is charged in the slow charge mode, and curve S10 of fig. 10b is a display SOC curve after the display SOC is corrected according to the SOC correction method provided in the above embodiment when the battery is charged in the slow charge mode. Curve S11 of fig. 10c is a display SOC curve in the related scheme when the battery is charged in the low current mode, and curve S12 of fig. 10c is a display SOC curve after the display SOC is corrected according to the SOC correction method provided in the above embodiment when the battery is charged in the low current mode. It is apparent from fig. 10a to 10b that, in one case, the display SOC curve in the related scheme is virtually low during the start time of charging, so that the increase speed of the display SOC is relatively fast during the latter period of charging to compensate for the slow increase speed before the compensation, however, in this way, the display SOC in the related scheme is left to stand for a long time at the end of charging after the display SOC is increased to virtually high; as can be seen from fig. 10c, in another case, if the display SOC in the related scheme is always in a virtual low state, the display SOC of the battery is corrected at the instant when the voltage of the battery during charging increases to a voltage value that can trigger the SOC correction, so that the display SOC is instantaneously increased. Obviously, the existing scheme cannot solve the situation of displaying the abnormal increase of the SOC in the two situations. However, as can be seen from fig. 10a to 10c, after the SOC correction method provided by the present application is applied, the display SOC is enabled to follow the actual SOC variation, so that the increase is more gradual, the gap between the display SOC and the actual SOC is gradually reduced, so that the SOC abrupt change phenomenon occurring at the charging end can be reduced in various charging modes, the duration of the SOC maintenance is reduced, the SOC variation is enabled to more conform to the actual SOC variation trend, and the SOC display accuracy of the battery is effectively improved.

It can be understood that the working principle and working process of the SOC correction method provided in the present application are only illustrated in the fast charge mode, the slow charge mode and the small current mode in the embodiments of the present application. The charging modes mentioned in the SOC correction method are not limited, and in other embodiments, the values of the parameters such as the first voltage threshold and the preset SOC may be adjusted according to the corresponding charging modes to implement the SOC correction method provided in the present application.

Referring to fig. 11, an embodiment of the present application further provides a battery module 10. The battery module 10 includes a battery 12, a processor 13, and a memory 14. The processor 13 is connected to the battery 12 and the memory 14. Memory 14 includes one or more computer instructions. One or more computer instructions are executed by the processor 13 for implementing the SOC correction method as set forth in any of the preceding claims. It will be appreciated that in some embodiments at least one of the processor 13 and the memory 14 may be integrated on the battery management system 11. In other embodiments, the processor 13 may also be a stand-alone controller. The battery 12 includes, but is not limited to, a rechargeable battery such as a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, a secondary alkaline zinc manganese battery, etc., and the type of battery 12 is not limited in this application.

With continued reference to fig. 12, an embodiment of the present application further provides an electronic device 1. The electronic device 1 includes the battery module 10 as described above. The electronic device 1 comprises at least two battery modules 10 as described above.

It is understood that the electronic device 1 may be a stand-alone power supply device, and the power conversion device may be integrated inside the electronic device 1, so that the electronic device 1 may form a micro grid system with an external power supply source, such as an ac power supply source, a dc power supply source. For example, the electronic apparatus 1 may be a household large-sized storage battery, a portable outdoor power source, or the like. In other embodiments, the electronic device 1 may be a device integrated with a battery module, including but not limited to a robot, a sweeper, a weeder, a notebook, etc., that requires a display of the battery SOC.

The present application also provides a computer-readable medium having stored thereon a computer program which, when executed by a processor, implements the SOC correction method as in the above technical scheme. The computer readable medium may take the form of a portable compact disc read only memory (CD-ROM) and include program code that can be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto, and in this document, a readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

The program product described above may take the form of any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium would include the following: an electrical connection having one or more wires, a portable disk, a hard disk, random Access Memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

The computer readable signal medium may include a data signal propagated in baseband or as part of a carrier wave with readable program code embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A readable signal medium may also be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device, partly on a remote computing device, or entirely on the remote computing device or server. In the case of remote computing devices, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., connected via the Internet using an Internet service provider).

Furthermore, the above-described drawings are only schematic illustrations of processes included in the method according to the exemplary embodiment of the present invention, and are not intended to be limiting. It will be readily appreciated that the processes shown in the above figures do not indicate or limit the temporal order of these processes. In addition, it is also readily understood that these processes may be performed synchronously or asynchronously, for example, among a plurality of modules.

In addition, those of ordinary skill in the art will recognize that the above embodiments are presented for purposes of illustration only and are not intended to be limiting, and that suitable modifications and variations of the above embodiments are within the scope of the disclosure of the present application.

Claims

1. An SOC correction method, comprising:

acquiring charging parameters of the battery in each operation period, wherein the charging parameters comprise display SOC and battery voltage;

when the charging parameters of the battery meet preset conditions, determining a target SOC of the battery;

determining an SOC correction coefficient according to the target SOC and the display SOC;

and updating the display SOC according to the SOC correction coefficient, and displaying the updated display SOC.

2. The SOC correction method of claim 1, wherein the determining the target SOC of the battery when the charging parameter of the battery satisfies a preset condition includes:

and when the display SOC is greater than or equal to a preset SOC and the battery voltage is less than a first voltage threshold, determining that the preset SOC is the target SOC.

3. The SOC correction method of claim 2, further comprising:

Determining a charging mode of the battery;

and determining the preset SOC and a first voltage threshold corresponding to the preset SOC according to the charging mode.

4. The SOC correction method of claim 1, wherein the determining the target SOC of the battery when the charging parameter of the battery satisfies a preset condition includes:

and when the battery voltage is greater than or equal to a first voltage threshold, determining a target SOC of the battery according to the battery voltage and a charging mode of the battery.

5. The SOC correction method of claim 4, wherein the determining a target SOC of the battery based on the battery voltage and a charging mode of the battery includes:

when the charging mode is a first charging mode, acquiring the charging current of the battery; determining the target SOC from the charging current and the battery voltage; or (b)

When the charging mode is a second charging mode, determining the target SOC according to the battery voltage and a preset mapping relation; the charging current in the first charging mode is greater than the charging current in the second charging mode.

6. The SOC correction method of any of claims 1-5, wherein the determining an SOC correction coefficient based on the target SOC and the display SOC includes:

Calculating the difference value of the target SOC and the display SOC to obtain a first SOC difference value;

calculating the difference value between the SOC of the battery when the battery is full and the target SOC to obtain a second SOC difference value;

determining an adjustment step according to the first SOC difference value and the second SOC difference value; wherein the adjustment step length and the first SOC difference value form a positive correlation, and the adjustment step length and the second SOC difference value form a negative correlation;

and calculating the sum of the initial correction coefficient and the adjustment step length to obtain the SOC correction coefficient.

7. The SOC correction method of any of claims 1-5, wherein the updating the display SOC according to the SOC correction coefficient includes:

calculating the SOC variation of the battery in the running period;

determining a target SOC variation according to the SOC correction coefficient and the SOC variation;

and updating the display SOC according to the target SOC variation.

8. The SOC correction method of any of claims 1-5, further comprising:

when the battery voltage is smaller than a second voltage threshold value, limiting the display SOC to be not larger than a preset SOC threshold value; or (b)

Updating the display SOC to the SOC at which the battery is full when the battery voltage is greater than or equal to the second voltage threshold; wherein the preset SOC threshold is less than the SOC of the battery when full.

9. A battery module comprising a battery, a processor, and a memory, the memory comprising one or more computer instructions executable by the processor for implementing the SOC modification method of any of claims 1-7.

10. An electronic device comprising the battery module according to claim 9.