CN117723978A

CN117723978A - Cell power state determining method, device, computer equipment and storage medium

Info

Publication number: CN117723978A
Application number: CN202311631424.3A
Authority: CN
Inventors: 李志飞; 杜仑; 程海峰; 桑文丽; 马宋宋; 徐良渡
Original assignee: Zhejiang Zero Run Technology Co Ltd; Zhejiang Lingxiao Energy Technology Co Ltd
Current assignee: Zhejiang Zero Run Technology Co Ltd; Zhejiang Lingxiao Energy Technology Co Ltd
Priority date: 2023-11-30
Filing date: 2023-11-30
Publication date: 2024-03-19

Abstract

The application relates to a method, a device, computer equipment and a storage medium for determining a battery cell power state. The method comprises the following steps: firstly, acquiring electric core data, charge-discharge protection voltage and power protection voltage, wherein the electric core data comprises current temperature and current charge state; then, determining a calibration power state based on the current temperature and the current state of charge; then, determining the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage; and finally, if the charging and discharging state is the charging and discharging state, determining an updating parameter based on the battery cell data and the power protection voltage, and determining a target power state based on the updating parameter and the calibration power state. The accuracy of the estimation of the power state of the battery cell is improved, and meanwhile, the overcharge and overdischarge of the battery cell are guaranteed, so that the battery cell health of the power battery is facilitated.

Description

Cell power state determining method, device, computer equipment and storage medium

Technical Field

The application relates to the technical field of new energy automobiles, in particular to a method and a device for determining a power state of a battery cell, computer equipment and a storage medium.

Background

With the advent of new energy automobiles, the new energy automobiles rapidly develop in the market due to the characteristics of strong practicability and diversified functions. The State Of the battery cell Power (SOP) including the allowable discharge Power and the allowable charge Power Of the Power battery is an important control parameter in the battery management system (Battery Management System, BMS). Under normal conditions, the SOP needs to be accurately estimated to meet the power requirement of the vehicle, if the estimation is too high, the battery cell is easily over-discharged, irreversible damage is caused, the health of the battery cell is not facilitated, and if the estimation is too low, the performance of the battery cell cannot be fully exerted, the capacity of the battery cell is wasted, and the cost performance of the vehicle is reduced.

In the prior art, a calibration method is generally adopted, pulse tests under different temperatures and different SOCs are carried out on the battery cells in an off-line mode, so that the SOP of the battery cells in the current state is obtained, and a power MAP table is formed. Or calculating the maximum corresponding current by off-line testing the internal resistance of the battery cell, the difference value of the current voltage and the protection voltage. However, in actual use, the battery cell is easily affected by factors such as aging, temperature and the like, the internal resistance is changed, the difference between the actual SOP and the calibration value in the power MAP table is increased, and overcharge and overdischarge of the battery cell are easily caused.

Therefore, there is a need in the art for a way to improve the accuracy of the estimation of the power state of the battery cells.

Disclosure of Invention

In view of the foregoing, it is desirable to provide a method, an apparatus, a computer device, and a computer-readable storage medium for determining a battery cell power state, which can improve the accuracy of battery cell power state estimation.

In a first aspect, the present application provides a method for determining a power state of a battery cell. The method comprises the following steps:

acquiring electric core data, charge-discharge protection voltage and power protection voltage, wherein the electric core data comprises current temperature and current state of charge;

determining a calibrated power state based on the current temperature and the current state of charge;

determining the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage;

and if the charging and discharging state is the charging and discharging state, determining an updating parameter based on the battery cell data and the power protection voltage, and determining a target power state based on the updating parameter and the calibration power state.

Optionally, in an embodiment of the present application, the cell data further includes a current voltage and a current flow direction, and determining the charge and discharge state of the cell based on the cell data and the charge and discharge protection voltage includes:

Judging whether the power core is in a charging state or a discharging state based on the current flow direction;

and judging the power core as being in a charging and discharging state or a charging and discharging ending state based on the current voltage and the charging and discharging protection voltage.

Optionally, in an embodiment of the present application, the calibrating the power state includes calibrating a permitted discharge current and calibrating a permitted charge current, and the method further includes:

if the current voltage is not less than the charging protection voltage and lasts for a preset time, the battery cell is in a charging end state, and a target power state is determined based on a charging limiting coefficient and the calibration allowable charging current;

and if the current voltage is not greater than the discharge protection voltage and lasts for a preset time, the battery cell is in a discharge end state, and a target power state is determined based on a discharge limiting coefficient and the calibration allowable discharge current.

Optionally, in an embodiment of the present application, the charge-discharge state includes a charging state, the cell data further includes a current voltage, the power protection voltage includes an upper power limit voltage, and if the charge-discharge state is the charging-discharge state, determining, based on the cell data and the power protection voltage, an update parameter, and determining, based on the update parameter and a calibration power state, a target power state includes:

And if the charging and discharging state is the charging state, judging whether the input power meets the preset standard or not based on the current voltage and the upper power limit voltage, and if the input power meets the preset standard, determining the calibrated power state as the target power state.

Optionally, in an embodiment of the present application, the battery cell data further includes a voltage at a previous time and a current at a previous time, and if the charge-discharge state is a charging-discharge state, determining, based on the battery cell data and the power protection voltage, an update parameter, and determining, based on the update parameter and the calibration power state, a target power state further includes:

if the current does not meet the preset standard, determining a voltage difference value based on the voltage at the last time and the current voltage, and determining the current internal resistance based on the voltage difference value and the current at the last time;

determining an upper limit difference value based on the current voltage and a power lower limit voltage, and determining an input power state based on the upper limit difference value and a preset redundancy threshold;

determining a residual power current based on the present internal resistance, an upper limit difference value, and an input power state;

a target power state is determined based on the residual power current and the nominal power state.

Optionally, in an embodiment of the present application, the charge-discharge state includes a discharging state, the cell data further includes a current voltage, the power protection voltage includes a lower power limit voltage, and if the charge-discharge state is the discharging state, determining, based on the cell data and the power protection voltage, an update parameter, and determining, based on the update parameter and the calibration power state, a target power state includes:

And if the charging and discharging state is the discharging state, judging whether the output power meets the preset standard or not based on the current voltage and the lower power limit voltage, and if the output power meets the preset standard, determining the calibrated power state as the target power state.

determining a lower limit value based on the current voltage and a lower power limit voltage, and determining an output power state based on the lower limit value and a preset redundancy threshold;

determining a residual power current based on the present internal resistance, a lower limit difference value, and an output power state;

In a second aspect, the present application further provides a device for determining a power state of a battery cell. The device comprises:

The data acquisition module is used for acquiring the electric core data, the charge-discharge protection voltage and the power protection voltage, wherein the electric core data comprises the current temperature and the current state of charge;

the calibration power state determining module is used for determining a calibration power state based on the current temperature and the current state of charge;

the charge and discharge state determining module is used for determining the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage;

and the target power state determining module is used for determining an updating parameter based on the battery cell data and the power protection voltage and determining a target power state based on the updating parameter and the calibration power state if the charging and discharging state is the charging and discharging state.

In a third aspect, the present application also provides a computer device. The computer device comprises a memory storing a computer program and a processor executing the steps of the method according to the various embodiments described above.

In a fourth aspect, the present application also provides a computer-readable storage medium. The computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements the steps of the method described in the above embodiments.

The method, the device, the computer equipment and the storage medium for determining the power state of the battery cell comprise the steps of firstly, acquiring battery cell data, charge-discharge protection voltage and power protection voltage, wherein the battery cell data comprises the current temperature and the current state of charge; then, determining a calibration power state based on the current temperature and the current state of charge; then, determining the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage; and finally, if the charging and discharging state is the charging and discharging state, determining an updating parameter based on the battery cell data and the power protection voltage, and determining a target power state based on the updating parameter and the calibration power state. That is, in the process of charging or discharging the battery core of the power battery, the actual power state SOP value corresponding to the current temperature and the state of charge is updated in real time by acquiring the battery core data in real time and combining the protection voltage, so that the power state is optimal, the estimation accuracy of the power state of the battery core is improved, the overcharge and overdischarge of the battery core are ensured, and the battery core health of the power battery is facilitated.

Drawings

FIG. 1 is a diagram of an application environment for a method of determining a power state of a battery cell in one embodiment;

FIG. 2 is a flow chart of a method of determining a power state of a battery cell according to an embodiment;

FIG. 3 is a schematic diagram of a state of charge peak voltage versus an upper power voltage limit in one embodiment;

FIG. 4 is a diagram of the lowest voltage versus lower power voltage for a discharge state in one embodiment;

FIG. 5 is a flowchart illustrating steps performed in an embodiment of a method for determining a power state of a battery cell;

FIG. 6 is a block diagram of a cell power state determination device in one embodiment;

fig. 7 is an internal structural diagram of a computer device in one embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

The method for determining the power state of the battery cell provided by the embodiment of the application can be applied to an application environment shown in fig. 1. Wherein the terminal 102 communicates with the server 104 via a network. The data storage system may store data that the server 104 needs to process. The data storage system may be integrated on the server 104 or may be located on a cloud or other network server. The terminal 102 may be, but not limited to, various personal computers, notebook computers, smart phones, tablet computers, internet of things devices, and portable wearable devices, where the internet of things devices may be smart speakers, smart televisions, smart air conditioners, smart vehicle devices, and the like. The portable wearable device may be a smart watch, smart bracelet, headset, or the like. The server 104 may be implemented as a stand-alone server or as a server cluster of multiple servers.

In one embodiment, as shown in fig. 2, a method for determining a power state of a battery cell is provided, and the method is applied to the server in fig. 1 for illustration, and includes the following steps:

s201: and acquiring the electric core data, the charge-discharge protection voltage and the power protection voltage, wherein the electric core data comprises the current temperature and the current state of charge.

In this embodiment, first, electric core data, charge-discharge protection voltage and power protection voltage are collected in real time, where the electric core data at least includes data such as current temperature, current state of charge SOC, real-time voltage, real-time current, etc., the charge-discharge protection voltage refers to a voltage protection upper and lower limit value that is considered unable to continue charging or discharging when the voltage drops or rises to a certain extent or below in the charging or discharging process of the electric core, and the power protection voltage refers to a voltage value corresponding to the most suitable charge-discharge power.

S203: and determining a calibration power state based on the current temperature and the current state of charge.

In the embodiment of the application, after the electric core data are acquired, the corresponding calibration power state is found by looking up the form of the power MAP table based on the current temperature and the current state of charge SOC therein. The power MAP table is a power state table with two dimensions of temperature and state of charge (SOC) obtained by charge and discharge test calibration at the battery cell level in the early stage, the form of the power MAP table is shown as follows, wherein the interval precision of the temperature and the state of charge is determined by a calibration process, and the corresponding determined value is a calibration power state.

Temperature/state of charge

0

20

40

60

80

100

Temperature 1

A

B

C

D

E

F

Temperature 2

G

H

I

J

K

L

Temperature 3

M

N

O

P

Q

R

Temperature 4

S

T

U

V

W

X

S205: and determining the charge and discharge states of the battery cells based on the battery cell data and the charge and discharge protection voltage.

In this embodiment of the present application, after determining the calibration power state based on the current temperature and the current state of charge, the charge and discharge state of the battery cell is determined based on the battery cell data and the charge and discharge protection voltage, specifically, the charge and discharge state refers to the current state of the battery cell, such as discharging, charging, discharging, and the like, where the current real-time current state of the collected battery cell can be combined, and the magnitudes of the real-time voltage and the charge and discharge protection voltage are compared, so as to determine which state the battery cell is in.

S207: and if the charging and discharging state is the charging and discharging state, determining an updating parameter based on the battery cell data and the power protection voltage, and determining a target power state based on the updating parameter and the calibration power state.

In this embodiment of the present application, if it is determined that the battery cell is currently in a charging state or a discharging state, an update parameter is determined based on collected battery cell data and a power protection voltage, specifically, whether the current charging input power or discharging output power meets a standard may be determined by determining a relationship between a real-time voltage and the power protection voltage, if there is more or less charging input power or discharging output power, the update parameter is determined as a specific residual value or a lack value, and then, based on the update parameter, an actual power state of the battery cell is determined based on a calibrated power state, that is, a target power state.

In the above method for determining the power state of the battery cell, firstly, obtaining the battery cell data, the charge-discharge protection voltage and the power protection voltage, wherein the battery cell data comprises the current temperature and the current state of charge; then, determining a calibration power state based on the current temperature and the current state of charge; then, determining the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage; and finally, if the charging and discharging state is the charging and discharging state, determining an updating parameter based on the battery cell data and the power protection voltage, and determining a target power state based on the updating parameter and the calibration power state. That is, in the process of charging or discharging the battery core of the power battery, the actual power state SOP value corresponding to the current temperature and the state of charge is updated in real time by acquiring the battery core data in real time and combining the protection voltage, so that the power state is optimal, the estimation accuracy of the power state of the battery core is improved, the overcharge and overdischarge of the battery core are ensured, and the battery core health of the power battery is facilitated.

In one embodiment of the present application, the battery cell data further includes a present voltage and current flow direction, and determining the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage includes:

S301: and judging whether the power core is in a charging state or a discharging state based on the current flow direction.

S303: and judging the power core as being in a charging and discharging state or a charging and discharging ending state based on the current voltage and the charging and discharging protection voltage.

In one embodiment of the present application, the collected cell data includes a current flow direction, and according to the current flow direction, it can be determined whether the cell is currently in a charging state or a discharging state, specifically, when the current flow direction is positive, it is indicated that the cell is in the discharging state, and when the current flow direction is negative, it is indicated that the cell is in the charging state. The collected battery cell data also comprises the current voltage, and according to the current voltage and the charge-discharge protection voltage, the battery cell can be judged to be in a charge-discharge state or a charge-discharge end state at present, specifically, if the current voltage reaches or exceeds the charge-discharge protection voltage for a certain time, that is, when the current voltage V_now is not less than the upper voltage protection limit V_Hpro or the current voltage V_now is not less than the lower voltage protection limit V_Lpro for a certain time, the battery cell is indicated to be in the charge-discharge end state at present, otherwise, when the current voltage V_now is less than the upper voltage protection limit V_Hpro or the current voltage V_now is not more than the lower voltage protection limit V_Lpro, the battery cell is indicated to be in the charge-discharge state at present. Optionally, the certain time is a redundant value, so as to prevent false triggering, and the specific value is selected according to the polarization characteristic of the battery cell, and generally 5s, 10s and the like can be selected.

In this embodiment, by determining that the battery cell is in a charging state or a discharging state based on the current flow direction, and determining that the battery cell is in a charging and discharging state or a charging and discharging end state based on the current voltage and the charging and discharging protection voltage, the current state of the battery cell can be accurately divided, the power state can be updated in time, and the influence of aging of the battery cell is small.

In one embodiment of the present application, the nominal power state includes a nominal allowed discharge current and a nominal allowed charge current, the method further comprising:

s401: and if the current voltage is not less than the charging protection voltage and lasts for a preset time, the battery cell is in a charging end state, and a target power state is determined based on the charging limiting coefficient and the calibration allowable charging current.

S403: and if the current voltage is not greater than the discharge protection voltage and lasts for a preset time, the battery cell is in a discharge end state, and a target power state is determined based on a discharge limiting coefficient and the calibration allowable discharge current.

In one embodiment of the present application, the determined calibration power states include a calibration allowable charge current char_curr_int and a calibration allowable discharge current dis_curr_int, when it is determined that the battery cell is currently in a charge-discharge end state, specifically, when the current voltage is not less than the charge protection voltage and lasts for a preset time, that is, when the current voltage v_now is greater than or equal to the voltage protection upper limit v_hpro and lasts for a certain time, the battery cell is in the charge end state, a target power state is determined according to the charge limiting coefficient and the calibration allowable charge current, and a specific calculation formula is as follows:

Char_Curr_int＝Lc*Char_Curr_int

Wherein Lc is a limiting coefficient, and is obtained by calibrating according to the polarization characteristic of the battery cell and the power characteristic of the whole vehicle.

When the current voltage is not greater than the discharge protection voltage and lasts for a preset time, namely the current voltage V_now is less than or equal to the voltage protection lower limit V_Lpro and lasts for a certain time, the battery cell is in a discharge end state, and then the target power state is determined according to the discharge limiting coefficient and the calibration allowable discharge current, wherein the specific calculation formula is as follows:

Dis_Curr_int＝Ld*Dis_Curr_int

and Ld is a limiting coefficient, and is obtained by calibrating according to the polarization characteristic of the battery cell and the power characteristic of the whole vehicle.

Optionally, the preset time is a redundancy value, so as to prevent false triggering, and the specific value is selected according to the polarization characteristic of the battery cell, and generally 5s, 10s and the like can be selected.

In this embodiment, if the current voltage is not less than the charging protection voltage and lasts for a preset time, the battery cell is in a charging end state, and the target power state is determined based on the charging limiting coefficient and the calibration allowable charging current. If the current voltage is not greater than the discharge protection voltage and lasts for the preset time, the battery cell is in a discharge end state, a target power state is determined based on the discharge limiting coefficient and the calibration allowable discharge current, and the power state can be updated in time according to the charge and discharge end state, so that the power current reaches the optimal value.

In one embodiment of the present application, the charge-discharge state includes a charging state, the cell data further includes a current voltage, the power protection voltage includes a power upper limit voltage, and if the charge-discharge state is the charging-discharge state, determining an update parameter based on the cell data and the power protection voltage, and determining a target power state based on the update parameter and a calibration power state includes:

In one embodiment of the present application, if the battery cell is in a charging state, i.e., the current voltage v_now < the upper voltage protection limit v_hpro, it is determined whether the input power meets a preset standard, i.e., whether the current charging input power is suitable or not, based on the current voltage and the upper power limit voltage, and in a specific application, it is determined whether the absolute value of the difference between the current voltage v_now and the upper power limit voltage v_high is less than the voltage redundancy threshold v_ syc, i.e., |v_now-v_high| < v_ syc, wherein the voltage redundancy threshold v_ syc is an experimental experience value. If the inequality is satisfied, it indicates that the current charging input power is appropriate, that is, meets the preset standard, as shown in scenario 2 in fig. 3, the calibration power state is determined to be the target power state, that is, the calibration power state corresponding to the current temperature and the current state of charge is not updated.

In this embodiment, if the charging and discharging state is the charging state, it is determined whether the input power meets the preset standard based on the current voltage and the upper power limit voltage, and if the input power meets the preset standard, the calibration power state is determined to be the target power state, so that the problem of excessive or insufficient power caused by deviation of the power lookup table due to inaccurate temperature acquisition can be avoided.

In an embodiment of the present application, the battery cell data further includes a last time voltage and a last time current, and if the charge-discharge state is a charge-discharge state, determining an update parameter based on the battery cell data and the power protection voltage, and determining the target power state based on the update parameter and the calibration power state further includes:

s501: if the current does not meet the preset standard, determining a voltage difference value based on the voltage at the last time and the current voltage, and determining the current internal resistance based on the voltage difference value and the current at the last time.

S503: an upper limit value is determined based on the current voltage and a power upper limit voltage, and an input power state is determined based on the upper limit value and a preset redundancy threshold.

S505: and determining a residual power current based on the current internal resistance, the upper limit difference value and the input power state.

S507: a target power state is determined based on the residual power current and the nominal power state.

In one embodiment of the present application, if the preset criterion is not met, i.e. the inequality is not satisfied, |v_now-v_high|is greater than or equal to v_ syc, it is indicated that the current charging input power is not suitable, more likely, less likely, the voltage difference is determined based on the previous time voltage and the current voltage, the current internal resistance is determined based on the voltage difference and the current at the previous time, specifically, the voltage difference Vdiff is obtained according to the voltage v_lsat and the current voltage v_now, and the current internal resistance r_last is determined according to the voltage difference Vdiff and the current value curr_last at the previous time, and the specific calculation formula is as follows:

Vdiff＝|V_lsat-V_now|，R_last＝Vdiff/Curr_last

then, an upper limit difference value is determined based on the current voltage and the upper power limit voltage, and an input power state is determined based on the upper limit difference value and a preset redundancy threshold, namely that the input power is more or less, specifically, the input power can be judged by an inequality v_high-v_now > v_ syc, if the inequality is satisfied, the current input power is less, as shown in a scenario 1 of fig. 3, and if the inequality is not satisfied, the current input power is more, as shown in a scenario 3 of fig. 3.

Then, determining an update parameter, namely a residual power current SY_curr, based on the current internal resistance R_last, the upper limit difference value V_high-V_now and the input power state, wherein the current internal resistance and the upper limit difference value determine the magnitude of the update parameter, the input power state determines the positive and negative of the update parameter, namely the negative when the input power is more, and the positive when the input power is less, and the specific calculation formula is as follows:

SY_Curr＝(V_high-V_now)/R_last

Recording SY_Curr as SYI_1, calculating residual power current meeting the standard for a plurality of times, averaging, updating on the basis of the calibration power state, and determining the target power state. The specific calculation formula is as follows:

Char_Curr_int＝Char_Curr_int+AVG(SY1+…+SYA)

wherein Char_Curr_int refers to the allowable charging current, SY1 and SYA refer to the residual power current meeting the standard calculated for a plurality of times, the standard meeting refers to the condition that the residual power current SY_Curr is calculated for A times in the state of charge floating sliding window change DeltaSOC at the current temperature, the floating sliding window change DeltaSOC is related to the state of charge SOC interval marked in the power MAP table, for example, the interval is 1, the DeltaSOC is also 1%, in specific application, the condition that the residual power current SY_Curr is calculated between 59 and 60 is calculated when the current SOC is 60, and the condition that the residual power current SY_Curr is calculated between 59.1 and 60.1 is calculated when the SOC is 60.1. The value of the times A is a tested value or a test calibration value.

In this embodiment, by determining a voltage difference value based on the voltage at the previous time and the current voltage, determining a current internal resistance based on the voltage difference value and the current at the previous time, determining an upper limit difference value based on the current voltage and the upper limit voltage of the power, determining an input power state based on the upper limit difference value and a preset redundancy threshold, determining a remaining power current based on the current internal resistance, the upper limit difference value and the input power state, and determining a target power state based on the remaining power current and the calibrated power state, the remaining power current amount can be estimated according to the real-time voltage and the upper limit voltage difference value of the power, and the power ammeter is updated continuously, so that the power is optimal. The power state is adjusted in real time by means of the voltage of the battery cell, so that the method is suitable for different battery cells and wide in application range.

In one embodiment of the present application, the charge-discharge state includes a discharging state, the cell data further includes a current voltage, the power protection voltage includes a power lower limit voltage, and if the charge-discharge state is the discharging state, determining an update parameter based on the cell data and the power protection voltage, and determining a target power state based on the update parameter and a calibration power state includes:

In one embodiment of the present application, if the battery cell is in a discharging state, i.e., the current voltage v_now > the voltage protection lower limit v_lpro, it is determined whether the output power meets a preset standard based on the current voltage and the power lower limit voltage, i.e., whether the current discharge output power is suitable, and in a specific application, it is determined whether the absolute value of the difference between the current voltage v_now and the power upper limit voltage v_low is smaller than the voltage redundancy threshold v_sy, i.e., |v_now-v_low| < v_sy, wherein the voltage redundancy threshold v_sy is an experimental experience value. If the inequality is satisfied, it indicates that the current discharge output power is appropriate, that is, meets the preset standard, and if the scenario 2 shown in fig. 4 is determined that the calibration power state is the target power state, that is, the calibration power state corresponding to the current temperature and the current state of charge is not updated.

In this embodiment, if the charge-discharge state is the discharging state, it is determined whether the output power meets the preset standard based on the current voltage and the lower power limit voltage, and if the output power meets the preset standard, the calibration power state is determined to be the target power state, so that the problem of excessive or insufficient power caused by deviation of the power lookup table due to inaccurate temperature acquisition can be avoided.

s601: if the current does not meet the preset standard, determining a voltage difference value based on the voltage at the last time and the current voltage, and determining the current internal resistance based on the voltage difference value and the current at the last time.

S603: and determining a lower limit value based on the current voltage and a lower power limit voltage, and determining an output power state based on the lower limit value and a preset redundancy threshold.

S605: and determining a residual power current based on the current internal resistance, the lower limit difference value and the output power state.

S607: a target power state is determined based on the residual power current and the nominal power state.

In one embodiment of the present application, if the preset criterion is not met, i.e. the inequality is not satisfied, |v_now-v_low|is not equal to or greater than v_sy, it is indicated that the current discharge output power is not suitable, more likely, less likely, the voltage difference is determined based on the previous time voltage and the current voltage, the current internal resistance is determined based on the voltage difference and the current at the previous time, specifically, the voltage difference Vdiff is obtained according to the voltage v_lsat and the current voltage v_now, and the current internal resistance r_last is determined according to the voltage difference Vdiff and the current value curr_last at the previous time, and the specific calculation formula is as follows:

Vdiff＝|V_lsat-V_now|，R_last＝Vdiff/Curr_last

then, a lower limit difference value is determined based on the current voltage and the lower power limit voltage, and an output power state, that is, more output power or less output power, is determined based on the lower limit difference value and a preset redundancy threshold, specifically, the output power state can be judged by an inequality v_now-v_low > v_sy, if the inequality is established, the current output power is indicated to be less, as shown in a scenario 1 of fig. 4, and if the inequality is not established, the current output power is indicated to be more, as shown in a scenario 3 of fig. 4.

Then, determining an update parameter, namely a residual power current SY_Curr, based on the current internal resistance R_last, an upper limit difference value V_now-V_low and an output power state, wherein the current internal resistance and the lower limit difference value determine the magnitude of the update parameter, the output power state determines the positive and negative of the update parameter, namely the negative when the output power is more, and the positive when the output power is less, and the specific calculation formula is as follows:

SY_Curr＝(V_now-V_low)/R_last

Dis_Curr_int＝Dis_Curr_int+AVG(SY1+…+SYN)

wherein dis_curr_int refers to allowable discharge current, SY1 and SYN refer to calculating residual power current meeting a standard for a plurality of times, the meeting standard refers to the situation that the residual power current sy_curr is calculated in the state of charge floating sliding window change Δsoc for N times under the current temperature, the floating sliding window change Δsoc is related to the state of charge SOC interval marked in the power MAP table, for example, the interval is 1, Δsoc is also 1%, in specific application, when the current SOC is 60, the situation that the residual power current sy_curr is calculated between 59-60 is calculated, and when the SOC is 60.1, the situation that the residual power current sy_curr is calculated between 59.1-60.1 is calculated. The number of times N is a tested value or a test calibration value.

In this embodiment, by determining a voltage difference value based on the voltage at the previous time and the current voltage, determining a current internal resistance based on the voltage difference value and the current at the previous time, determining a lower limit difference value based on the current voltage and the lower limit voltage of the power, determining an output power state based on the lower limit difference value and a preset redundancy threshold, determining a remaining power current based on the current internal resistance, the lower limit difference value and the output power state, and determining a target power state based on the remaining power current and the calibration power state, the remaining power current amount can be estimated according to the real-time voltage and the lower limit voltage difference value of the power, and the power ammeter is updated continuously, so that the power is optimal. The power state is adjusted in real time by means of the voltage of the battery cell, so that the method is suitable for different battery cells and wide in application range.

The following describes, in one embodiment, the steps of a method for determining a power state of a battery cell according to the present application. As shown in fig. 5, first, at S701, cell data including a current temperature and a current state of charge, a charge-discharge protection voltage, and a power protection voltage are acquired. Thereafter, a calibration power state is determined based on the current temperature and the current state of charge, S703. For example, the current state of charge SOC is 50%, and the maximum allowable charge current char_curr_int and the maximum allowable discharge current dis_curr_int are determined by table look-up.

Then, S705 determines the charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage. Specifically, S707 to S709 determine that the current flow direction determines that the cell is in a charging state or a discharging state, and determine that the cell is in a charging/discharging state or a charging/discharging end state based on the current voltage and the charging/discharging protection voltage. S711, if the current voltage is not less than the charging protection voltage and lasts for a preset time, the battery cell is in a charging end state, and a target power state is determined based on a charging limiting coefficient and the calibration allowable charging current; judging that v_now > =3600 mV and lasts for 1 second, v_hpro is the upper voltage protection limit, if yes, char_curr_int=0% char_curr_int, lc is a limiting coefficient, returning to S701; if not, the process proceeds to S715. And S713, if the current voltage is not greater than the discharge protection voltage and lasts for a preset time, the battery cell is in a discharge end state, and a target power state is determined based on the discharge limiting coefficient and the calibration allowable discharge current. Judging that the current voltage v_now < =2000 mV and lasts for 3 seconds, if yes, returning to S701, wherein dis_curr_int=10%; if not, the process proceeds to S715.

And S715, if the charging and discharging state is the charging and discharging state, determining an updating parameter based on the battery cell data and the power protection voltage, and determining a target power state based on the updating parameter and the calibration power state. Specifically, if the charge and discharge state is the charging state, S717 determines whether the input power meets a preset standard based on the current voltage and the upper power voltage, and if so, determines that the calibration power state is the target power state. That is, it is judged that |v_now-3500mv| <20mV, if yes, the process returns to S701. If not, S719-725, if not, determining a voltage difference value based on the voltage at the last time and the current voltage, and determining the current internal resistance based on the voltage difference value and the current at the last time; determining an upper limit difference value based on the current voltage and a power lower limit voltage, and determining an input power state based on the upper limit difference value and a preset redundancy threshold; determining a residual power current based on the present internal resistance, an upper limit difference value, and an input power state; a target power state is determined based on the residual power current and the nominal power state.

And judging 3500-V_now >20mV. If yes, the voltage difference is calculated according to the voltage V_lsat (3200 mV) at the previous moment and the current voltage V_now (3400 mV), and Vdiff= |3200-3400|=200mV; calculating internal resistance r_last=200/10000=0.002 according to current value curr_last (-10000 mA) at the last moment; estimating a residual power current sy_curr= (3500-3400)/0.002=50000 mA according to the calculated internal resistance r_last; recording the SY_Curr as SYI_1, updating the corresponding Char_Curr_int=Char_Curr_int+AVG (SY1+ … +SY3) at the current temperature of 50% when the SY_Curr calculation is met for 3 times within ΔSOC=1%, and avG (SY1+ … +SY3) is the average value of 3 SYI.

If not, the voltage difference is calculated according to the 3200mV voltage and the 3550mV voltage at the previous moment, and Vdiff= |3200-3550|=350 mV; calculating internal resistance r_last=350/10000=0.035 according to current value curr_last (-10000 mA) at the last moment; estimating a residual power current SY_Curr= (3500-3550)/0.035= -14280mA according to the calculated internal resistance R_last; recording the SY_Curr as SYI_1, updating the corresponding Char_Curr_int=Char_Curr_int+AVG (SY1+ … +SY3) at the current temperature of 50% when the SY_Curr calculation is met for 3 times within ΔSOC=1%, and avG (SY1+ … +SY3) is the average value of 3 SYI.

In another discharging case, S727, if the charging and discharging state is in a discharging state, determining whether the output power meets a preset standard based on the current voltage and the power lower limit voltage, and if so, determining that the calibration power state is the target power state. Judging that the I V_now-2500mV is <20mV, if yes, returning to S701, if not, S729-735, if not, determining a voltage difference value based on the voltage at the last time and the current at the last time, and determining the current internal resistance based on the voltage difference value and the current at the last time; determining a lower limit value based on the current voltage and a lower power limit voltage, and determining an output power state based on the lower limit value and a preset redundancy threshold; determining a residual power current based on the present internal resistance, a lower limit difference value, and an output power state; a target power state is determined based on the residual power current and the nominal power state.

V_now-2500mV >20mV was judged. If yes, the voltage difference is calculated according to the voltage V_lsat (3300 mV) at the previous moment and the current voltage V_now (3000 mV), and Vdiff= |3300-3000|; calculating internal resistance r_last=300/10000=0.03 according to current value curr_last (10000 mA) at the last moment; estimating a residual power current sy_curr= (3000 mV-2500 mV)/0.03= 16666mA according to the calculated internal resistance r_last; recording the SY_Curr as SYI_1, and updating the corresponding Dis_Curr_int=Dis_Curr_int+AVG (SY1+ … +SY3) at the current temperature of 50% when the SY_Curr calculation is met for 3 times within ΔSOC=1%, wherein AVG (SY1+ … +SY3) is the average value of 3 SYI times.

If not, the voltage difference is calculated according to the voltage (3300 mV) at the previous moment and the current voltage (2100 mV), and Vdiff= |3300-2100|=1200mV; calculating internal resistance r_last=1200/10000=0.12 according to current value curr_last (10000 mA) at the last moment; estimating a residual power current SY_Curr= (2100 mV-2500 mV)/0.12= -3333mA according to the calculated internal resistance R_last; recording the SY_Curr as SYI_1, and updating the corresponding Dis_Curr_int=Dis_Curr_int+AVG (SY1+ … +SY3) at the current temperature of 50% when the SY_Curr calculation is met for 3 times within ΔSOC=1%, wherein AVG (SY1+ … +SY3) is the average value of 3 SYI times.

It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.

Based on the same inventive concept, the embodiment of the application also provides a battery cell power state determining device for realizing the above-mentioned related battery cell power state determining method. The implementation of the solution provided by the device is similar to the implementation described in the above method, so the specific limitation in the embodiments of the device for determining a cell power state provided below may be referred to the limitation of the method for determining a cell power state hereinabove, and will not be repeated herein.

In one embodiment, as shown in fig. 6, there is provided a cell power state determining apparatus 600, comprising: a data acquisition module 601, a calibration power state determination module 603, a charge and discharge state determination module 605, and a target power state determination module 607, wherein:

the data acquisition module 601 is configured to acquire electrical core data, a charge-discharge protection voltage, and a power protection voltage, where the electrical core data includes a current temperature and a current state of charge.

A calibration power state determination module 603 is configured to determine a calibration power state based on the current temperature and the current state of charge.

The charge and discharge state determining module 605 is configured to determine a charge and discharge state of the battery cell based on the battery cell data and the charge and discharge protection voltage.

And a target power state determining module 607, configured to determine an update parameter based on the cell data and the power protection voltage, and determine a target power state based on the update parameter and a calibration power state if the charge-discharge state is in a charge-discharge state.

In one embodiment of the present application, the cell data further includes a present voltage and current flow direction, and the charge and discharge state determining module is further configured to:

In one embodiment of the present application, the nominal power state includes a nominal allowed discharge current and a nominal allowed charge current, and the target power state determination module is further configured to:

In one embodiment of the present application, the charge-discharge state includes a charging state, the cell data further includes a current voltage, the power protection voltage includes a power upper limit voltage, and the target power state determination module is further configured to:

In one embodiment of the present application, the cell data further includes a last time voltage and a last time current, and the target power state determining module is further configured to:

In one embodiment of the present application, the charge-discharge state includes a discharging state, the cell data further includes a current voltage, the power protection voltage includes a lower power limit voltage, and the target power state determination module is further configured to:

The above-described respective modules in the cell power state determination apparatus may be implemented in whole or in part by software, hardware, and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and the internal structure of which may be as shown in fig. 7. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a method of determining a power state of a battery cell. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be keys, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by those skilled in the art that the structure shown in fig. 7 is merely a block diagram of some of the structures associated with the present application and is not limiting of the computer device to which the present application may be applied, and that a particular computer device may include more or fewer components than shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the method embodiments described above when the computer program is executed.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the steps of the method embodiments described above.

In an embodiment, a computer program product is provided, comprising a computer program which, when executed by a processor, implements the steps of the method embodiments described above.

It should be noted that, user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, presented data, etc.) referred to in the present application are information and data authorized by the user or sufficiently authorized by each party.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in the various embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the various embodiments provided herein may include at least one of relational databases and non-relational databases. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processors referred to in the embodiments provided herein may be general purpose processors, central processing units, graphics processors, digital signal processors, programmable logic units, quantum computing-based data processing logic units, etc., without being limited thereto.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.

Claims

1. A method of determining a power state of a battery cell, the method comprising:

2. The method of claim 1, wherein the cell data further comprises a present voltage and current flow direction, and wherein determining the charge-discharge state of the cell based on the cell data and the charge-discharge protection voltage comprises:

3. The method of claim 2, wherein the nominal power state comprises a nominal allowed discharge current and a nominal allowed charge current, the method further comprising:

4. The method of claim 1, wherein the charge-discharge state comprises a charging state, the cell data further comprises a present voltage, the power protection voltage comprises a power upper limit voltage, and determining an update parameter based on the cell data and the power protection voltage if the charge-discharge state is the charging-discharge state, determining a target power state based on the update parameter and a nominal power state comprises:

5. The method of claim 4, wherein the cell data further comprises a last time voltage and a last time current, wherein if the charge-discharge state is a charging-discharge state, determining an update parameter based on the cell data and a power protection voltage, and determining a target power state based on the update parameter and a nominal power state further comprises:

6. The method of claim 1, wherein the charge-discharge state comprises a discharging state, the cell data further comprises a present voltage, the power protection voltage comprises a lower power limit voltage, and determining an update parameter based on the cell data and the power protection voltage if the charge-discharge state is the discharging state, determining a target power state based on the update parameter and a nominal power state comprises:

7. The method of claim 6, wherein the cell data further comprises a last time voltage and a last time current, wherein if the charge-discharge state is a charging-discharge state, determining an update parameter based on the cell data and a power protection voltage, and determining a target power state based on the update parameter and a nominal power state further comprises:

8. A cell power state determination apparatus, the apparatus comprising:

9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 7 when the computer program is executed.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.