CN116670524A - Method and device for determining state of charge (SOC) of battery pack - Google Patents

Method and device for determining state of charge (SOC) of battery pack Download PDF

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Publication number
CN116670524A
CN116670524A CN202180085513.5A CN202180085513A CN116670524A CN 116670524 A CN116670524 A CN 116670524A CN 202180085513 A CN202180085513 A CN 202180085513A CN 116670524 A CN116670524 A CN 116670524A
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China
Prior art keywords
display
soc
display period
period
battery pack
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CN202180085513.5A
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Chinese (zh)
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黄磊
陈晨
徐广玉
赵微
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Contemporary Amperex Technology Co Ltd
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Contemporary Amperex Technology Co Ltd
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Publication of CN116670524A publication Critical patent/CN116670524A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC

Abstract

The application provides a method and a device for determining a state of charge (SOC) of a battery pack, and relates to the field of battery management. In the method, the actual SOC of the mth sampling period corresponding to the current time k and the display SOC of the nth display period corresponding to the current time k are obtained, wherein the current time k is the time before the end of the nth display period; determining the change rate of the display SOC of the (n+1) th display period according to the charge and discharge state of the battery pack at the current moment k, the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period; and determining the display SOC of the (n+1) th display period according to the change rate of the display SOC of the (n+1) th display period and the display SOC of the (n) th display period. Thus, correction of the display SOC is realized, and the SOC displayed at the n+1th moment is more accurate.

Description

Method and device for determining state of charge (SOC) of battery pack Technical Field
The present application relates to the field of battery management, and in particular, to a method and apparatus for determining a state of charge SOC of a battery pack.
Background
When an electronic device powered by a battery is in use, a display interface of the electronic device typically displays a state of charge (SOC) of the battery. The display SOC may be used to indicate the current remaining charge of the battery so that the user charges or discharges the battery.
However, there is often a deviation between the display SOC and the actual SOC, and how to accurately represent the actual SOC becomes a technical problem to be solved in the field of battery management.
Disclosure of Invention
The application aims to provide a method and a device for determining a display state of charge (SOC) of a battery pack, which are used for improving the accuracy of displaying the SOC.
In a first aspect, the present application provides a method of determining a displayed state of charge, SOC, of a battery pack, comprising:
acquiring an actual SOC of an mth sampling period corresponding to a current time k and a display SOC of an nth display period corresponding to the current time k, wherein the current time k is a time before the end of the nth display period;
determining the change rate of the display SOC of the (n+1) th display period according to the charge and discharge state of the battery pack at the current moment k, the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period;
and determining the display SOC of the (n+1) th display period according to the change rate of the display SOC of the (n+1) th display period and the display SOC of the (n+1) th display period, wherein n is an integer greater than or equal to 1, m is an integer greater than or equal to 1, and k is an integer greater than or equal to 1.
In the above method, when the display SOC at the nth time is deviated from the actual SOC at the nth time, the change rate of the display SOC at the n+1 time may be determined based on the charge/discharge state at the nth time. Further, the display SOC at the n+1th time is calculated from the display SOC at the n time and the determined change rate. Thus, correction of the display SOC is achieved, and the display SOC observed by the user at the n+1th moment is more accurate.
In one possible implementation form of the present application,
the determining the change rate of the display SOC of the n+1th display period according to the charge and discharge state of the battery pack at the current time k, the display SOC of the nth display period, the actual SOC of the mth sampling period, and the change rate of the display SOC of the nth display period includes:
and under the condition that the battery pack is in a charging state at the current moment k and does not reach the charging end, determining the change rate of the display SOC of the (n+1) th display period according to the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period.
In one possible implementation form of the present application,
determining a rate of change of the display SOC for the (n+1) -th display period according to the following formula:
ChangeRate(n+1)＝KC*ChangeRate(n)*[1-(DSOC(n)-ASOC(m))/(FSOC-DSOC(n))]；
wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
ChangeRate (n) is the rate of change of the display SOC for the nth display period;
DSOC (n) is the display SOC of the nth display period of the current time k;
the ASOC (m) is the actual SOC of the mth sampling period of the current moment k;
FSOC is the corresponding display SOC when the set battery pack is fully charged, and the FSOC is larger than DSOC (n);
KC is a preset first adaptive tuning parameter, where KC ε (0, 1).
In one possible implementation form of the present application,
the determining the change rate of the display SOC of the n+1th display period according to the charge and discharge state of the battery pack at the current time k, the display SOC of the nth display period, the actual SOC of the mth sampling period, and the change rate of the display SOC of the nth display period includes:
determining a change rate of the display SOC of the (n+1) -th display period according to the following formula in a case where the battery pack is in a discharge state at the current time k:
ChangeRate(n+1)＝KD*ChangeRate(n)*[1+(DSOC(n)-ASOC(m))/DSOC(n)]；
wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
ChangeRate (n) is the rate of change of the display SOC for the nth display period;
DSOC (n) is the display SOC of the nth display period of the current time k, and is not 0;
the actual SOC (m) is the actual SOC of the mth sampling period of the current moment k;
KD is a preset second adaptive regulation parameter, wherein KD epsilon (0, 1)
In a possible embodiment, the determining the display SOC of the n+1th display period according to the change rate of the display SOC of the n+1th display period and the display SOC of the n display period includes:
calculating the display SOC at the n+1 time according to the formula DSOC (n+1) =dsoc (n) +stepoc (n+1) ×cd×changerate (n+1);
wherein DSOC (n+1) is the display SOC of the n+1th display period;
DSOC (n) is the display SOC of the nth display period;
stepoc (n+1) is the amount of change in actual SOC in the n+1th display period;
and Cd is a value representing the current direction, when the battery pack is in a charging state, the Cd is +1, and when the battery pack is in a discharging state, the Cd is-1.
In a possible embodiment, the variation of the actual SOC in the n+1th display period is determined by:
StepSOC(n+1)＝Td*I(k)/Ncap；
wherein Td is the duration of one display period;
i (k) is the current value of the battery pack at the current moment k;
ncap is the nominal capacity of the battery pack.
In a second aspect, the present application also provides an apparatus for determining a display state of charge SOC of a battery pack, including:
the acquisition module is used for acquiring the actual SOC of the mth sampling period corresponding to the current time k and the display SOC of the nth display period corresponding to the current time k, wherein the current time k is the time before the end of the nth display period;
the determining module is used for determining the change rate of the display SOC of the (n+1) th display period according to the charge and discharge state of the battery pack at the current moment k, the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period;
the calculation module is used for determining the display SOC of the (n+1) th display period according to the change rate of the display SOC of the (n+1) th display period and the display SOC of the (n+1) th display period, wherein n is an integer greater than or equal to 1, m is an integer greater than or equal to 1, and k is an integer greater than or equal to 1.
In a third aspect, the present application also provides a battery management chip, including: comprising a processor and a memory storing computer readable instructions which, when executed by the processor, perform a method according to the first aspect of the application.
In a fourth aspect, an embodiment of the present application provides an electronic device comprising a processor and a memory storing computer readable instructions which, when executed by the processor, perform the steps of the method as provided in the first aspect above.
In a fifth aspect, an embodiment of the present application provides a readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of the method as provided in the first aspect above.
Additional features and advantages of the application will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the embodiments of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a method for determining a display SOC of a battery pack according to an embodiment of the present application;
fig. 2 is a schematic diagram of two cycles of SOC of a battery pack of the battery pack according to an embodiment of the present application;
fig. 3 is a flowchart two of a method for determining a display SOC of a battery pack according to an embodiment of the present application;
FIG. 4 is a functional block diagram of a battery pack display SOC device according to an embodiment of the present application;
fig. 5 is a circuit connection block diagram of an electronic device according to an embodiment of the present application.
Detailed Description
Interpretation of technical terms:
SOC: state of charge (SOC), the ratio of the remaining capacity of the battery after a period of use or long-term rest to the capacity of its fully charged state.
Displaying SOC: the state of charge of the battery pack is displayed on a display screen of the electronic device.
Actual SOC: the true state of charge of the battery pack of the electronic device.
Terminal voltage: the voltage values of the two ends of the battery core are collected by the power management system.
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application.
Currently, the correction display SOC method is: acquiring a plurality of battery working parameters (such as current, temperature, terminal voltage and the like) of a battery, inputting the battery working parameters into a preset open-circuit voltage calculation model to calculate the open-circuit voltage of the battery, and judging whether the display SOC needs to be calibrated according to the open-circuit voltage value; if yes, determining the open circuit voltage value and displaying the open circuit voltage value of the battery according to a preset calibration table
Target calibration coefficients at SOC; and calibrating the display SOC according to the target calibration coefficient. However, the open circuit voltage value obtained by calculation according to the open circuit voltage calculation model is limited by the model error and the battery cell characteristics of the LFP battery cell, the calculated real SOC is not accurate enough, the display SOC after calibration is also inaccurate, the phenomena of uneven calculation speed, jump and the like of the display SOC can occur, and the use experience of a user is affected.
The application provides a method for determining a state of charge (SOC) of a battery pack, which is applied to electronic equipment needing to display the SOC to a user. Specifically, a battery management system (Battery Management System, abbreviated as BMS) may be disposed in the electronic device, and the method for determining the display SOC of the battery pack provided by the present application may be specifically applied to the BMS. The electronic device may be, but is not limited to, an electronic device powered by a battery pack, such as a smart phone, a tablet computer, an electric automobile, etc.
As shown in fig. 1, the method for determining the display state of charge SOC of the battery pack according to the embodiment of the present application may include the following steps.
S21: and acquiring the actual SOC of the mth sampling period corresponding to the current time k and the display SOC of the nth display period corresponding to the current time k.
The current time k is the time before the end of the nth display period. Illustratively, the current time k may be any time after the nth display period and the nth display period is a specified proportion. For example, the current time k may be any time after four fifth of the nth display period. For example, the current time k may be at a nine tenth period time of the nth display period. As another example, the current time k may be at a fourteenth period time of fifteenth display period.
The current time may be located at a critical time of two adjacent sampling periods, or may be located in any one sampling period.
The power management system typically records parameters associated with the battery pack, such as charge and discharge status, actual SOC, display SOC, etc., for each acquisition time period within a fixed time period. Alternatively, the time length of each parameter acquisition period may be the same or different (in the example shown in fig. 2, the display period of the display SOC is different from the sampling period of the actual SOC).
As a possible implementation manner, the battery management system acquires and records the actual SOC in each sampling period; the display SOC in each display period is acquired and recorded in the display period.
The sampling period may be a fixed value during the active use of the battery pack, and the display period may be a fixed value during the active use of the battery pack, depending on specific requirements. Currently, if there are other demands, the sampling period may take different values at different life stages of the battery pack, and the display period may take different values at different life stages of the battery pack.
As shown in fig. 2, two cycle diagrams of the battery pack are shown in the drawing, a display cycle and a sampling cycle, respectively. Wherein a plurality of display periods are shown on the display period: td1, td2, td3, …, td (n), td (n+1), …, and the display SOC corresponding to each display period, for example, the display SOC corresponding to the first display period Td1 is DSOC (1) and the display SOC corresponding to the nth display period Td (n) is DSOC (n). A number of sampling periods are shown over the sampling period: ts1, ts2, ts3, …, ts (m), …, and an actual SOC corresponding to each sampling period, for example, the actual SOC corresponding to the first sampling period Ts1 is ASOC (1), and the actual SOC corresponding to the mth display period Td (m) is ASOC (m).
In the example shown in fig. 2, the current time k is a critical time between the nth display period T (n) and the nth display period T (n+1), and the current time k is located in the mth sampling period.
In order to facilitate recording of different moments and sampling periods and display periods corresponding to the moments, the moments are recorded as: time 0, time 1, time 2, time 3, … …, time k-1, time k, time k+1, time …. The sampling period is recorded as: sample period 1, sample period 2, sample period 3, sample period … …, sample period m-1, sample period m, sample period m+1th sample period …. The display period is recorded as: the 1 st display period, the 2 nd display period, the 3 rd display period, … …, the n-1 st display period, the n display period, the n+1 th display period …. Wherein k, n and m are integers greater than or equal to 1.
As one possible implementation, the electronic device may acquire the display SOC by: the electronic device records and displays the SOC to the memory before each power-down. At the initial time of powering up the electronic device, the display SOC recorded before the last powering down of the memory may be read as the display SOC of the 1 st display period.
As a possible implementation manner, the electronic device may obtain the actual SOC by: parameters such as the current temperature, current, working condition and usable electric quantity interval of the battery core in the battery pack are collected, and in each sampling period, the actual SOC in each sampling period is calculated according to the parameters such as the temperature, current, working condition and usable electric quantity interval of the battery core in the battery pack and an ampere-hour integration method.
As a possible implementation manner, as shown in fig. 2, the battery management system may determine, according to the current time k, an mth sampling period and an nth display period that the current time k falls into. Based on the time at which the current time k is located, the actual SOC of the mth sampling period and the display SOC of the nth display period corresponding to the current time k may be determined.
As a possible implementation manner, the current time k is a time before the end of the nth display period, and the next time k+1 of the current time k may be a time when the n+1th display period starts.
S22: and determining the change rate of the display SOC of the (n+1) th display period according to the charge and discharge state of the battery pack, the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period at the current moment k.
The charging and discharging states comprise a charging state and a discharging state, wherein the charging state comprises a direct charging state and a recharging state.
As a possible implementation manner, when detecting that a charging device (such as a charging gun, a charging bank and the like) is plugged into a charging interface of the electronic device and the current direction is an input direction, acquiring that the battery pack is in a direct charging state; on the other hand, when the charging interface of the electronic equipment is not detected to be plugged with charging equipment (such as a charging gun, a charging device and the like) and the current direction is the input direction, acquiring that the battery pack is in a recharging state; in yet another aspect, when the current direction of the electronic device is detected as the output direction, the battery pack is obtained to be in a discharge state.
In general, the display SOC at the same time is deviated from the actual SOC. Wherein the deviation includes being higher or lower. It can be understood that if the display SOC of the nth display period corresponding to the current time k is greater than the actual SOC of the mth sampling period or exceeds the first preset magnitude of the actual SOC of the mth sampling period, it is determined that the display SOC of the nth display period is higher; if the actual SOC of the mth sampling period corresponding to the current time k is larger than the display SOC of the nth display period or exceeds the display SOC of the nth display period by a second preset amplitude, determining that the display SOC of the nth display period is lower.
As a possible implementation manner, S22 may specifically be: when the battery pack is in a charged state at the current time k and the charging end is not reached, the display SOC at the time n+1 is calculated according to the display SOC at the time n and the change rate of the display SOC at the time n+1.
Based on the above, S22 may include the following four possible embodiments:
the first scheme is as follows: when the battery pack is in a charging state at the current moment k and does not reach the charging end and the display SOC of the nth display period is higher, determining the change rate of the display SOC of the (n+1) th display period according to the change rate of the display SOC of the nth display period, wherein the change rate of the display SOC of the (n+1) th display period is smaller than the change rate of the display SOC of the (n) th display period.
In this embodiment, when the battery pack is in a charged state at the current time k and does not reach the charging end and the display SOC of the nth display period is higher, the rate of change of the display SOC needs to be reduced in the (n+1) th display period so that the display SOC of the (n+1) th display period is closer to the actual SOC.
The second scheme is as follows: when the battery pack is in a charging state at the current moment k and does not reach the charging end and the display SOC of the nth display period is low, determining the change rate of the display SOC of the (n+1) th display period according to the change rate of the display SOC of the nth display period, wherein the change rate of the display SOC of the (n+1) th display period is larger than the change rate of the display SOC of the (n) th display period.
In this embodiment, when the battery pack is in a charged state at the current time k and does not reach the charging end, and the display SOC of the nth display period is low, the rate of change of the display SOC needs to be increased in the (n+1) th display period, so that the display SOC at the (n+1) th time is closer to the actual SOC.
In this embodiment, in the first and second aspects described above, it may be determined that the battery pack is in the charge end state when it is detected that any one of the following conditions is satisfied. Conditions include, but are not limited to: the current value of the charging current is smaller than a preset current value, the voltage value of the cell terminal voltage of the battery pack is larger than a preset voltage value, or the magnitude of the display SOC is larger than a preset SOC value. Otherwise, it is determined that the battery pack is not in the end-of-charge state.
When the charging end is not reached, the display SOC of the n+1th display period is calculated using the change rate of the display SOC of the n+1th display period, and the accuracy of the display SOC can be achieved without occurrence of a jump.
Third scheme: when the battery pack is in a discharging state at the current moment k and the display SOC of the nth display period is higher, determining the change rate of the display SOC of the (n+1) th display period according to the change rate of the display SOC of the nth display period, wherein the change rate of the display SOC of the (n+1) th display period is larger than the change rate of the display SOC of the (n) th display period.
In this embodiment, when the battery pack is in a discharge state at the current time k and the display SOC of the nth display period is high, the rate of change of the display SOC needs to be increased in the (n+1) th display period so that the display SOC at the (n+1) th time is closer to the actual SOC.
Fourth scheme: when the battery pack is in a discharging state at the current moment k and the display SOC of the nth display period is lower, determining the change rate of the display SOC of the (n+1) th display period according to the change rate of the display SOC of the nth display period, wherein the change rate of the display SOC of the (n+1) th display period is smaller than the change rate of the display SOC of the (n) th display period.
In this embodiment, when the battery pack is in a discharge state at the current time k and the display SOC of the nth display period is low, the rate of change of the display SOC needs to be reduced in the (n+1) th display period so that the display SOC of the (n+1) th display period is closer to the actual SOC.
S23: and determining the display SOC of the (n+1) th display period according to the change rate of the display SOC of the (n+1) th display period and the display SOC of the (n) th display period.
It is understood that the display SOC of the n+1th display period depends on at least the magnitude of the display SOC of the n-th display period and the rate of change of the display SOC of the n+1th display period. This iterative calculation manner allows the display SOC of the next display period to have higher accuracy.
As one possible implementation, the scheme of determining the display SOC of the n+1th display period includes, but is not limited to, the following two:
scheme one: if the battery pack is in a discharge state, determining a change rate of the display SOC of the (n+1) th display period according to the following formula:
ChangeRate(n+1)＝KD*ChangeRate(n)*[1+(DSOC(n)-ASOC(n))/(DSOC(n))]。
wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
ChangeRate (n) is the rate of change of the display SOC for the nth display period;
DSOC (n) is the display SOC of the nth display period of the current time k;
the ASOC (n) is the actual SOC of the mth sampling period of the current moment k;
KD is a second preset adaptive tuning parameter, wherein KD epsilon (0, 1).
It can be understood that (DSOC (n) -ASOC (n))/DSOC (n) is a deviation rate showing SOC when the battery pack is in a discharged state. When the difference between DSOC (n) and ASOC (n) is greater than 0, it indicates that the SOC is higher, the rate of change of the SOC is lower, and [1+ (DSOC (n) -ASOC (n))/DSOC (n) ] is greater than 1, the ChangeRate (n+1) may be greater than ChangeRate (n). When DSOC (n) -ASOC (n) is less than 0, it is indicated that the SOC is displayed to be low, the rate of change of the SOC is displayed to be high, and [1+ (DSOC (n) -ASOC (n))/DSOC (n) ] is less than 1, the ChangeRate (n+1) may be made smaller than ChangeRate (n).
Scheme II: if the battery pack is in a charged state and does not reach a charged end state, determining a change rate of the display SOC of the (n+1) th display period according to the following formula:
ChangeRate(n+1)＝KC*ChangeRate(n)*[1-(DSOC(n)-ASOC(n))/(FSOC-DSOC(n))]，
wherein,
ChangeRate (n+1) is the rate of change of the display SOC for the (n+1) th display period;
ChangeRate (n) is the rate of change of the display SOC for the nth display period;
DSOC (n) is the display SOC of the nth display period of the current time k;
the ASOC (n) is the actual SOC of the mth sampling period of the current moment k;
FSOC is the corresponding display SOC when the set battery pack is full;
KC is a preset first adaptive tuning parameter, where KC ε (0, 1).
For example, (DSOC (n) -ASOC (n))/(FSOC-DSOC (n)) is a deviation rate showing SOC when the battery pack is in a charged state and the end-of-charge state is not reached. The FSOC is greater than DSOC (n) because the charge end is not reached. When DSOC (n) -ASOC (n) is greater than 0, the instruction shows that SOC is higher, and [1- (DSOC (n) -ASOC (n))/(FSOC-DSOC (n)) ] is less than 1, changeRate (n+1) may be made smaller than ChangeRate (n). When DSOC (n) -ASOC (n) is less than 0, the description shows that SOC is low, and [1- (DSOC (n) -ASOC (n))/(FSOC-DSOC (n)) ] is greater than 1, changeRate (n+1) may be made greater than ChangeRate (n).
As one possible implementation, calculating the display SOC of the n+1th display period may be performed as follows:
as shown in fig. 3, the method for determining the display SOC for calculating the n+1th display period includes:
s31: and judging whether the battery pack is in a charging state and does not reach a charging end state.
If so, S32 is performed.
S32: the display SOC for the n+1th display period is calculated according to the following formula:
DSOC(n+1)＝DSOC(n)+StepSOC(n+1)*Cd*ChangeRate(n+1)；
wherein DSOC (n+1) shows SOC for time n+1;
the display SOC (n) is the display SOC at the nth time;
stepoc (n+1) is the amount of change in actual SOC in the n+1th display period;
and Cd is a value representing the current direction, when the battery pack is in a charging state, the Cd is +1, and when the battery pack is in a discharging state, the Cd is-1.
The change amount of the actual SOC in one display period can be calculated by an ampere-hour integration method and the actual current flowing through the battery pack. Illustratively, the above-described amount of change in the actual SOC in the n+1th display period may be determined by:
StepSOC(n+1)＝Td*I(k)/Ncap；
wherein Td is the duration of one display period;
i (k) is the current value of the battery pack at the current moment k, and the current value I (k) of the battery pack is the current value of the main loop at the current moment k in the charging and discharging process of the battery pack.
Ncap is the nominal capacity of the battery pack. In this embodiment, the nominal capacity Ncap of the battery pack is a preset value, and may be determined according to the currently calculated battery pack.
In the present embodiment, the display SOC at the n+1 th time in the first embodiment is calculated from the change rate (n+1) of the display SOC at the n+1 th time, and the change rate (n+1) of the display SOC at the n+1 th time is calculated from the actual SOC.
Referring to fig. 3, the present application further provides an apparatus 40 for determining a state of charge SOC of a battery pack, which is applied to an electronic device powered by the battery pack in an operating state. Specifically, the electronic device includes a battery management system (Battery Management System, abbreviated as BMS), and the display SOC determination method of the battery pack described above may be specifically applied to the BMS. It should be noted that, in the device 40 for determining SOC of a battery pack according to the embodiment of the present application, the basic principle and the technical effects thereof are the same as those of the above embodiment, and for brevity, reference may be made to the corresponding contents of the above embodiment. The apparatus 40 comprises an acquisition module 41, a determination module 42 and a calculation module 43, wherein,
an obtaining module 41, configured to obtain an actual SOC of an mth sampling period corresponding to a current time k and a display SOC of an nth display period corresponding to the current time k, where the current time k is a time before the end of the nth display period;
a determining module 42, configured to determine a rate of change of the display SOC of the n+1th display period according to the charge/discharge state of the battery pack at the current time k, the display SOC of the n display period, the actual SOC of the m sampling period, and the rate of change of the display SOC of the n display period;
the calculating module 43 is configured to determine the display SOC of the n+1th display period according to the change rate of the display SOC of the n+1th display period and the display SOC of the n display period, where n is an integer greater than or equal to 1, m is an integer greater than or equal to 1, and k is an integer greater than or equal to 1.
In a possible design, the determining module 42 may be specifically configured to determine, when the battery pack is in a charging state at the current time k and does not reach the charging end, a rate of change of the display SOC of the n+1th display period according to the display SOC of the n-th display period, the actual SOC of the m-th sampling period, and the rate of change of the display SOC of the n-th display period.
In one possible embodiment, the rate of change of the display SOC of the n+1th display period is determined according to the following formula:
ChangeRate(n+1)＝KC*ChangeRate(n)*[1-(DSOC(n)-ASOC(m))/(FSOC-DSOC(n))]；
wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
ChangeRate (n) is the rate of change of the display SOC for the nth display period;
DSOC (n) is the display SOC of the nth display period of the current time k;
the ASOC (m) is the actual SOC of the mth sampling period of the current moment k;
FSOC is the corresponding display SOC when the set battery pack is fully charged, and the FSOC is larger than DSOC (n);
KC is a preset first adaptive tuning parameter, where KC ε (0, 1).
In one possible embodiment, when the battery pack is in a discharge state at the current time k, the rate of change of the display SOC of the n+1th display period is determined according to the following formula:
ChangeRate(n+1)＝KD*ChangeRate(n)*[1+(DSOC(n)-ASOC(m))/DSOC(n)]；
wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
ChangeRate (n) is the rate of change of the display SOC for the nth display period;
DSOC (n) is the display SOC of the nth display period of the current time k, and is not 0;
the actual SOC (m) is the actual SOC of the mth sampling period of the current moment k;
KD is a second preset adaptive tuning parameter, wherein KD epsilon (0, 1).
In one possible design, the calculation module 43 may be specifically configured to:
calculating the display SOC at the n+1 time according to the formula DSOC (n+1) =dsoc (n) +stepoc (n+1) ×cd×changerate (n+1);
wherein DSOC (n+1) is the display SOC of the n+1th display period;
DSOC (n) is the display SOC of the nth display period;
stepoc (n+1) is the amount of change in actual SOC in the n+1th display period;
and Cd is a value representing the current direction, when the battery pack is in a charging state, the Cd is +1, and when the battery pack is in a discharging state, the Cd is-1.
In one possible embodiment, the change in the actual SOC in the n+1th display period is determined by:
StepSOC(n+1)＝Td*I(k)/Ncap；
wherein Td is the duration of one display period;
i (k) is the current value of the battery pack at the current moment k;
ncap is the nominal capacity of the battery pack.
The above prior art solutions have all the drawbacks that the inventors have obtained after practice and careful study, and thus the discovery process of the above problems and the solutions presented below by the embodiments of the present application for the above problems should be all contributions to the present application by the inventors during the present application.
In addition, the application also provides a battery management chip, which comprises: comprising a processor and a memory storing computer readable instructions which, when executed by the processor, perform a method of determining the display SOC of a battery pack as in the above-described embodiment of the application.
Referring to fig. 4, fig. 4 is a schematic structural diagram of an electronic device for performing a display SOC determining method of a battery pack according to an embodiment of the present application, the electronic device may include: at least one processor 110, such as a CPU, at least one communication interface 120, at least one memory 130, and at least one communication bus 140. Wherein the communication bus 140 is used to enable direct connection communication of these components. The communication interface 120 of the device in the embodiment of the present application is used for performing signaling or data communication with other node devices. The memory 130 may be a high-speed RAM memory or a nonvolatile memory (non-volatile memory), such as at least one disk memory. Memory 130 may also optionally be at least one storage device located remotely from the aforementioned processor. The memory 130 has stored therein computer readable instructions which, when executed by the processor 110, perform the method process described above in fig. 2.
It will be appreciated that the configuration shown in fig. 4 is merely illustrative, and that the electronic device may also include more or fewer components than shown in fig. 4, or have a different configuration than shown in fig. 4. The components shown in fig. 4 may be implemented in hardware, software, or a combination thereof.
The apparatus may be a module, a program segment, or code on an electronic device. It should be understood that the apparatus corresponds to the above embodiment of the method of fig. 2, and is capable of performing the steps involved in the embodiment of the method of fig. 2, and specific functions of the apparatus may be referred to in the above description, and detailed descriptions thereof are omitted herein as appropriate to avoid redundancy.
It should be noted that, for convenience and brevity, a person skilled in the art will clearly understand that, for the specific working procedure of the system and apparatus described above, reference may be made to the corresponding procedure in the foregoing method embodiment, and the description will not be repeated here.
An embodiment of the application provides a readable storage medium having stored thereon a computer program which, when executed by a processor, performs a method procedure performed by an electronic device in the method embodiment shown in fig. 2.
The present embodiment discloses a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, are capable of performing the methods provided by the above-described method embodiments, for example, comprising: acquiring a charge and discharge state of a battery pack at an nth time, a display SOC at the nth time and an actual SOC at the nth time; determining a deviation of the display SOC from an actual SOC at the nth time; determining the change rate of the display SOC at the time n+1 according to the deviation and the charge and discharge state at the time n; and calculating the display SOC at the n+1th moment according to the change rate of the display SOC at the n+1th moment and the display SOC at the n moment, wherein n is an integer greater than or equal to 1.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.
Further, the units described as separate units may or may not be physically separate, and units displayed as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
Furthermore, functional modules in various embodiments of the present application may be integrated together to form a single portion, or each module may exist alone, or two or more modules may be integrated to form a single portion.
In this document, relational terms such as first and second, and the like may be 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.
The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

  1. A method of determining a state of charge, SOC, of a battery pack, comprising:
    acquiring an actual SOC of an mth sampling period corresponding to a current time k and a display SOC of an nth display period corresponding to the current time k, wherein the current time k is a time before the end of the nth display period;
    determining the change rate of the display SOC of the (n+1) th display period according to the charge and discharge state of the battery pack at the current moment k, the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period;
    and determining the display SOC of the (n+1) th display period according to the change rate of the display SOC of the (n+1) th display period and the display SOC of the (n+1) th display period, wherein n is an integer greater than or equal to 1, m is an integer greater than or equal to 1, and k is an integer greater than or equal to 1.
  2. The method according to claim 1, wherein the determining the change rate of the display SOC of the n+1th display period according to the charge-discharge state of the battery pack at the current time k, the display SOC of the n-th display period, the actual SOC of the m-th sampling period, and the change rate of the display SOC of the n-th display period includes:
    and under the condition that the battery pack is in a charging state at the current moment k and does not reach the charging end, determining the change rate of the display SOC of the (n+1) th display period according to the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period.
  3. The method of claim 2, wherein the rate of change of the display SOC for the n+1th display period is determined according to the following formula:
    ChangeRate(n+1)＝KC*ChangeRate(n)*[1-(DSOC(n)-ASOC(m))/(FSOC-DSOC(n))]；
    wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
    ChangeRate (n) is the rate of change of the display SOC for the nth display period;
    DSOC (n) is the display SOC of the nth display period of the current time k;
    the ASOC (m) is the actual SOC of the mth sampling period of the current moment k;
    FSOC is the corresponding display SOC when the set battery pack is fully charged, and the FSOC is larger than DSOC (n);
    KC is a preset first adaptive tuning parameter, where KC ε (0, 1).
  4. The method according to claim 1, wherein the determining the change rate of the display SOC of the n+1th display period according to the charge-discharge state of the battery pack at the current time k, the display SOC of the n-th display period, the actual SOC of the m-th sampling period, and the change rate of the display SOC of the n-th display period includes:
    determining a change rate of the display SOC of the (n+1) -th display period according to the following formula in a case where the battery pack is in a discharge state at the current time k:
    ChangeRate(n+1)＝KD*ChangeRate(n)*[1+(DSOC(n)-ASOC(m))/DSOC(n)]；
    wherein ChangeRate (n+1) is the rate of change of the display SOC for the n+1th display period;
    ChangeRate (n) is the rate of change of the display SOC for the nth display period;
    DSOC (n) is the display SOC of the nth display period of the current time k, and is not 0;
    the actual SOC (m) is the actual SOC of the mth sampling period of the current moment k;
    KD is a second preset adaptive tuning parameter, wherein KD epsilon (0, 1).
  5. The method according to claim 3 or 4, wherein the determining the display SOC of the n+1th display period from the rate of change of the display SOC of the n+1th display period and the display SOC of the n display period includes:
    calculating the display SOC at the n+1 time according to the formula DSOC (n+1) =dsoc (n) +stepoc (n+1) ×cd×changerate (n+1);
    wherein DSOC (n+1) is the display SOC of the n+1th display period;
    DSOC (n) is the display SOC of the nth display period;
    stepoc (n+1) is the amount of change in actual SOC in the n+1th display period;
    and Cd is a value representing the current direction, when the battery pack is in a charging state, the Cd is +1, and when the battery pack is in a discharging state, the Cd is-1.
  6. The method according to claim 5, wherein the amount of change in the actual SOC in the n+1th display period is determined by:
    StepSOC(n+1)＝Td*I(k)/Ncap；
    wherein Td is the duration of one display period;
    i (k) is the current value of the battery pack at the current moment k;
    ncap is the nominal capacity of the battery pack.
  7. An apparatus for determining a state of charge, SOC, of a battery pack, comprising:
    the acquisition module is used for acquiring the actual SOC of the mth sampling period corresponding to the current time k and the display SOC of the nth display period corresponding to the current time k, wherein the current time k is the time before the end of the nth display period;
    the determining module is used for determining the change rate of the display SOC of the (n+1) th display period according to the charge and discharge state of the battery pack at the current moment k, the display SOC of the (n) th display period, the actual SOC of the (m) th sampling period and the change rate of the display SOC of the (n) th display period;
    the calculation module is used for determining the display SOC of the (n+1) th display period according to the change rate of the display SOC of the (n+1) th display period and the display SOC of the (n+1) th display period, wherein n is an integer greater than or equal to 1, m is an integer greater than or equal to 1, and k is an integer greater than or equal to 1.
  8. A battery management chip, comprising: comprising a processor and a memory storing computer readable instructions which, when executed by the processor, perform the method of any of claims 1-6.
  9. An electronic device comprising a processor and a memory storing computer readable instructions that, when executed by the processor, perform the method of any of claims 1-6.
  10. A readable storage medium having stored thereon a computer program which, when executed by a processor, performs the method of any of claims 1-6.
CN202180085513.5A 2021-09-26 2021-09-26 Method and device for determining state of charge (SOC) of battery pack Pending CN116670524A (en)

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