CN114895205A

CN114895205A - Battery model parameter acquisition method and device, computer equipment and storage medium

Info

Publication number: CN114895205A
Application number: CN202210353819.0A
Authority: CN
Inventors: 王莹; 王彤; 项小雷; 秦雨默; 张艺铭; 丁浩
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2022-04-06
Filing date: 2022-04-06
Publication date: 2022-08-12

Abstract

The application relates to a method and a device for acquiring parameters of a battery model, a computer device, a storage medium and a computer program product. The method comprises the following steps: the target battery is tested for multiple times at different temperatures through the charging and discharging equipment to obtain a test curve, and the target test curves corresponding to the temperatures are determined. And for each temperature, carrying out curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data. For each temperature, a state of charge interval is determined based on the curve slope data. Pulse times for pulse testing are obtained based on the charge state intervals to determine a voltage profile. And performing parameter fitting through a pre-constructed equivalent circuit model based on the voltage change curves corresponding to the temperatures respectively to obtain parameters of a battery model corresponding to the target battery. Thus, the accuracy of the battery model parameters is greatly increased.

Description

Battery model parameter acquisition method and device, computer equipment and storage medium

Technical Field

The present application relates to the field of new energy battery technologies, and in particular, to a method and an apparatus for obtaining battery model parameters, a computer device, a storage medium, and a computer program product.

Background

With the development of new energy battery technology, in order to evaluate the performance of a battery, simulation modeling needs to be performed on the battery to be evaluated. In the process of modeling the battery, parameters of a battery model need to be acquired.

In The conventional technology, in order to obtain parameters of a battery model, HPPC (The Hybrid Pulse Power Characterization, Hybrid Pulse Power performance test) test acquisition may be adopted. During the HPPC test, data is often collected at the same SOC (State Of Charge) interval to save test time. This results in too little data to be collected, and the parameters of the battery model cannot be accurately obtained, thereby greatly reducing the accuracy of obtaining the parameters of the battery model.

Disclosure of Invention

In view of the above, it is necessary to provide a method, an apparatus, a computer device, a computer readable storage medium, and a computer program product for acquiring parameters of a battery model.

In a first aspect, the present application provides a method for obtaining parameters of a battery model. The method comprises the following steps:

the method comprises the steps that a target battery is tested for multiple times at different temperatures through charging and discharging equipment to obtain test curves, and the target test curves corresponding to the temperatures are determined; wherein the target test curve represents the situation that the voltage changes along with the change of the charge state in the test process;

for each temperature, carrying out curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature;

for each temperature, determining a charge state interval corresponding to the target test curve at the corresponding temperature based on curve slope data corresponding to the target test curve at the corresponding temperature, wherein the charge state interval represents an adjustment value of a charge state during a pulse test;

for each temperature, determining a plurality of pulse currents corresponding to the corresponding temperature, and determining pulse time at the corresponding temperature based on the charge state interval and the pulse current corresponding to the target test curve at the corresponding temperature, wherein the pulse time is used for indicating the charge and discharge equipment to perform pulse test;

obtaining voltage change curves which are obtained by performing pulse testing on the target battery by the charging and discharging equipment based on the pulse time and respectively correspond to the temperatures, wherein the voltage change curves represent the change conditions of the voltage along with the pulse current and the time;

and performing parameter fitting through a pre-constructed equivalent circuit model based on the voltage change curves corresponding to the temperatures respectively to obtain parameters of a battery model corresponding to the target battery.

In a second aspect, the application further provides a device for acquiring parameters of the battery model. The device comprises:

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 implementing the following steps when executing the computer program:

In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium, on which a computer program is stored which, when executed by a processor, carries out the steps of:

In a fifth aspect, the present application further provides a computer program product. The computer program product comprising a computer program which when executed by a processor performs the steps of:

According to the method and the device for acquiring the battery model parameters, the computer equipment, the storage medium and the computer program product, the target battery is tested for multiple times at different temperatures through the charging and discharging equipment to obtain the test curve, and the target test curve corresponding to each temperature with high truth and accuracy can be determined from multiple tests; wherein the target test curve characterizes a change in voltage with a change in state of charge during the test. And for each temperature, carrying out curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature. Therefore, whether the curve change is smooth or not in the charging and discharging process can be clearly reflected. For each temperature, a state of charge interval corresponding to the target test curve at the respective temperature is determined based on curve slope data corresponding to the target test curve at the respective temperature, wherein the state of charge interval characterizes an adjustment value of a state of charge during the pulse test. Therefore, according to the curve change condition represented by the target test curve, the adjustment value of the charge state matched with the curve change condition can be quickly and effectively determined, and the time cost of the subsequent parameter determination process is greatly saved. For each temperature, determining a plurality of pulse currents corresponding to the corresponding temperature, and determining pulse time at the corresponding temperature based on the charge state interval and the pulse current corresponding to the target test curve at the corresponding temperature, wherein the pulse time is used for indicating the charge and discharge equipment to perform pulse test. In this way, the pulse time for the pulse test can be reflected in real time. And obtaining voltage change curves which are obtained by performing pulse test on the target battery by the charging and discharging equipment based on the pulse time and respectively correspond to the temperatures, wherein the voltage change curves represent the change conditions of the voltage along with the pulse current and the time. And performing parameter fitting through a pre-constructed equivalent circuit model based on the voltage change curves corresponding to the temperatures respectively to obtain parameters of a battery model corresponding to the target battery. Therefore, on the premise of saving time, the parameters of the battery model with high accuracy can be obtained, and the accuracy of the parameters of the battery model is greatly improved.

Drawings

FIG. 1 is a diagram of an exemplary embodiment of a method for obtaining parameters of a battery model;

FIG. 2 is a schematic flow chart illustrating a method for obtaining parameters of a battery model according to an embodiment;

FIG. 3 is a graph illustrating a target discharge curve according to an embodiment;

FIG. 4 is a graph illustrating pulsed current, state of charge, voltage curves according to one embodiment;

FIG. 5 is a schematic diagram of an equivalent circuit model in one embodiment;

FIG. 6 is a schematic flow chart diagram illustrating the step of determining a target test curve in one embodiment;

FIG. 7 is a schematic flow chart of the step of determining slope data of a curve in one embodiment;

FIG. 8 is a graph illustrating a first derivative curve in one embodiment;

FIG. 9 is a graph showing a comparison of experimental data in one example;

FIG. 10 is a block diagram showing an example of a configuration of a device for acquiring parameters of a battery model;

FIG. 11 is a diagram illustrating an internal structure 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 is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The method for acquiring the battery model parameters provided by the embodiment of the application can be applied to the application environment shown in fig. 1. Wherein the charging and discharging device 102 communicates with the computer device 104 through a network. The data storage system may store data that computer device 104 needs to process. The data storage system may be integrated on the computer device 104, or may be located on the cloud or other network server. Based on the test curves obtained by testing the target battery for multiple times at different temperatures by the charging and discharging device 102, the computer device 104 determines the target test curves corresponding to the temperatures respectively; wherein the target test curve characterizes a change in voltage with a change in state of charge during the test. For each temperature, the computer device 104 performs curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature. For each temperature, based on the curve slope data corresponding to the target test curve at the respective temperature, the computer device 104 determines a state of charge interval corresponding to the target test curve at the respective temperature, wherein the state of charge interval characterizes an adjustment value of the state of charge during the pulse test. For each temperature, a plurality of pulse currents corresponding to the respective temperature are determined, and based on the charge state interval, the pulse current, corresponding to the target test curve at the respective temperature, a pulse time at the respective temperature is determined, the pulse time being used to instruct the charging and discharging device 102 to perform a pulse test. The computer device 104 obtains voltage variation curves which are obtained by performing pulse test on the target battery through the charging and discharging device 102 based on the pulse time and respectively correspond to the temperatures, and the voltage variation curves represent the variation conditions of the voltage along with the pulse current and the time. Based on the voltage change curves corresponding to the respective temperatures, the computer device 104 performs parameter fitting through a pre-constructed equivalent circuit model to obtain parameters of a battery model corresponding to the target battery. The charging and discharging device 102 may be an electronic measuring device having a charging function and a discharging function, among others. The computer device 104 may indeed be a terminal or a server. The terminal can be but not limited to various personal computers, notebook computers, smart phones, tablet computers, internet of things equipment and portable wearable equipment, and the internet of things equipment can be smart sound boxes, smart televisions, smart air conditioners, smart vehicle-mounted equipment and the like. The portable wearable device can be a smart watch, a smart bracelet, a head-mounted device, and the like. The server may be implemented as a stand-alone server or as a server cluster consisting of a plurality of servers.

In one embodiment, as shown in fig. 2, a method for obtaining parameters of a battery model is provided, which is described by taking the method as an example applied to the computer device in fig. 1, and includes the following steps:

step S202, obtaining a test curve based on multiple tests of a target battery at different temperatures by charging and discharging equipment, and determining target test curves corresponding to the temperatures respectively; wherein the target test curve characterizes a change in voltage with a change in state of charge during the test.

The charging and discharging equipment is an electronic measuring instrument and can be used for carrying out charging and discharging tests on the battery. The test curve may be a charging test curve of a charging process or a discharging test curve of a discharging process. The independent variable Of the test curve and the target test curve is SOC (State Of Charge) and the dependent variable is the voltage Of the battery. Wherein the SOC represents a percentage of the remaining available power of the battery to the total capacity of the battery. The target test curve may be a target charging test curve in a charging process or a target discharging test curve in a discharging process. Wherein the temperature can be-20 deg.C, -10 deg.C, 0 deg.C, 15 deg.C, 25 deg.C, 35 deg.C, 45 deg.C. Typically at-30 ℃ to 50 ℃.

Specifically, the computer device obtains a test curve obtained by performing multiple charging and discharging tests on the battery cell of the target battery at different temperatures by the charging and discharging device. The test curve can be a discharge test curve in a discharge process or a charge test curve in a charge process. And determining the capacity of the test curve based on the test curve. For each temperature, the computer device determines a target test curve corresponding to the respective temperature from the plurality of test curves based on a capacity of the test curve corresponding to the respective temperature. And the charging and discharging equipment performs a plurality of charging and discharging tests on the battery cell at each temperature.

For example, in the case that the temperature of the charging and discharging device is 25 ℃, the charging and discharging device performs 5 charging tests on the battery core of the target battery, and each charging and discharging test obtains a charging test curve C11 and a discharging test curve C12. The computer device obtains 5 charge test curves and 5 discharge test curves at 25 ℃, and determines the capacity of each charge test curve and the capacity of each discharge test curve. The computer device determines a target charging curve at 25 ℃ from among the 5 charging test curves based on the capacities corresponding to the charging test curves, respectively. And a target discharge curve at 25 ℃ was determined from the 5 discharge test curves based on the capacities corresponding to the discharge test curves, respectively. As shown in fig. 3, which is a target discharge curve at 25 ℃, the ordinate Voltage is Voltage and the abscissa SOC is state of charge.

And S204, for each temperature, carrying out curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature.

Wherein the slope of the curve identifies slope data used to determine the curve. Where each point in the target test curve represents a voltage value at a certain state of charge (i.e., SOC). The curve slope data can represent the change condition of two adjacent points in the curve, and therefore, the change condition of the whole target test curve can be represented.

Specifically, for each temperature, the computer device identifies a slope of the target test curve corresponding to the corresponding temperature to obtain slope data of the curve corresponding to each point of the target test curve at the corresponding temperature.

For example, at 25 ℃, the computer device performs curve slope identification on the target charging curve to obtain curve slope data corresponding to each point in the target charging curve. And the computer equipment identifies the slope of the target discharge curve to obtain the slope data of the curve corresponding to each point in the target discharge line.

Step S206, for each temperature, determining a charge state interval corresponding to the target test curve at the corresponding temperature based on the curve slope data corresponding to the target test curve at the corresponding temperature, wherein the charge state interval represents an adjustment value of the charge state during the pulse test.

Wherein the charge state interval characterizes a difference between two charge states.

Specifically, for each temperature, the computer device takes, as a first state of charge, a state of charge corresponding to a large change in curvature slope data, and takes, as a second state of charge, a state of charge corresponding to a gentle change in curvature slope data, based on curve slope data corresponding to a target test curve at the corresponding temperature. The computer device determines a charge state interval for the first charge state as a first interval and determines a charge interval for the second charge state as a second interval. Wherein the first interval is smaller than the second interval. Wherein the first interval for large changes in curvature slope data may be between 1.5% and 3%, and the second interval for gentle changes in curvature slope data may be between 5% and 10%.

It should be noted that, the large change of curvature slope data proves that the voltage change is large when the charge state of each unit is changed; the curve slope data changes smoothly, which proves that the charge state changes little for every unit change. A large change in curvature slope data may be characterized as a rapid rise or a rapid fall on the curve, and a smooth change in curve slope data may be characterized as a smooth curve.

Step S208, determining a plurality of pulse currents corresponding to the corresponding temperatures for each temperature, and determining pulse time at the corresponding temperatures based on the charge state intervals and the pulse currents corresponding to the target test curves at the corresponding temperatures, wherein the pulse time is used for indicating the charge and discharge equipment to perform pulse tests.

Specifically, for each temperature, the computer device determines a current range corresponding to the respective temperature, and determines a plurality of pulse currents from the current range corresponding to the respective temperature. And determining the pulse time at the corresponding temperature based on the charge state interval and the pulse current corresponding to the target test curve at the corresponding temperature. And the computer equipment sends the pulse time and each pulse current respectively corresponding to each pulse current at the corresponding temperature to the charging and discharging equipment. And the charging and discharging equipment performs pulse testing based on the pulse time and the pulse current to obtain voltage change curves corresponding to all temperatures respectively. Wherein, in the process of pulse test, the standing time T is more than or equal to 5min after each pulse is finished, for example, the standing time T is more than or equal to 8min and less than or equal to 180 min. Wherein at 25 ℃, the interval of the state of charge is 2% with a state of charge of less than 20%, 5% with a state of charge of between 20% and 80%, and 2% with a state of charge of more than 80% and less than 100%.

It should be noted that each temperature corresponds to a current range, and any two current ranges may overlap, may have an intersection, and may not overlap. For example, the current range at 25 ℃ and 15 ℃ is the same at the normal temperature, such as from 1C to 3C, and the current range at the subzero temperature is different from that at the normal temperature, and considering that the battery is damaged by too high temperature at the subzero temperature, the current range at the subzero temperature is generally not as high as 3C (the battery capacity is 40Ah, i.e. the pulse current is 120 Ah).

Step S210, obtaining voltage variation curves corresponding to the temperatures respectively, obtained by performing a pulse test on the target battery based on the pulse time by the charging and discharging device, where the voltage variation curves represent the variation of the voltage with the pulse current and the time.

Specifically, for each temperature, the charging and discharging equipment performs pulse testing at the corresponding temperature according to the pulse time of the target test curve, so as to obtain voltage change curves corresponding to the temperatures respectively. And the computer equipment acquires voltage change curves corresponding to the temperatures sent by the charging and discharging equipment respectively. As shown in fig. 4, a voltage (i.e., voltage) variation curve is 4c, where 4a is a pulse law of a pulse current (i.e., current) in the pulse test, and 4b is a change of a state of charge (SOC) with Time when the pulse test is performed according to pulses at various times (i.e., Time in the figure) in 4 a.

Step S212, performing parameter fitting through a pre-established equivalent circuit model based on the voltage variation curves corresponding to the respective temperatures to obtain parameters of the battery model corresponding to the target battery.

The equivalent circuit model in the present application is a second-order equivalent circuit model, and the equivalent circuit model is formed by connecting an equivalent circuit with a power supply Voc, an ohmic internal resistance R0 and 2 RC units in series, and each RC unit is formed by connecting a polarization resistor and a polarization capacitor in parallel, as shown in fig. 5 specifically. The parameters include ohmic resistance, polarization resistance, time constant, polarization capacitance.

Specifically, the computer device performs parameter fitting on voltage change curves corresponding to the temperatures respectively through a pre-established equivalent circuit model to obtain parameters corresponding to the temperatures, the pulse currents and the charge states. For example, when the temperature is t, the pulse current is I1, and the state of charge is X1, the value of ohmic resistance, the value of polarization resistance, the value of time constant, and the value of polarization capacitance are given. The parameter fitting can be performed by at least one of data processing software such as Matlab, GT-sute, Amesim and the like through a least square method, a Bayesian identification algorithm and a Kalman filtering algorithm.

Wherein, the formula of the equivalent circuit model is as follows:

C ₁ ＝τ ₁ /R ₁

C ₂ ＝τ ₂ /R ₂

wherein U is the battery terminal voltage, U _oc Is an open circuit voltage, R ₀ Is ohmic resistance, R1, R2 are polarization resistances, tau ₁ 、τ ₂ For time constants, C1 and C2 are polarization capacitors, and I is a pulse current. Wherein, the order N of the RC loop is more than or equal to 1, preferably, N is more than or equal to 2 and less than or equal to 5; the model with too few RC loop orders is not accurate enough, and the RC loop is too large in calculation amount, so that parameter identification and simulation are not facilitated.

In the method for acquiring the parameters of the battery model, the target battery is tested for multiple times at different temperatures based on the charging and discharging equipment to obtain the test curve, and the target test curve corresponding to each temperature with high truth and accuracy can be determined from multiple tests; wherein the target test curve characterizes a change in voltage with a change in state of charge during the test. And for each temperature, carrying out curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature. Therefore, whether the curve change is smooth or not in the charging and discharging process can be clearly reflected. For each temperature, a state of charge interval corresponding to the target test curve at the respective temperature is determined based on curve slope data corresponding to the target test curve at the respective temperature, wherein the state of charge interval characterizes an adjustment value of a state of charge during the pulse test. Therefore, according to the curve change condition represented by the target test curve, the adjustment value of the charge state matched with the curve change condition can be quickly and effectively determined, and the time cost of the subsequent parameter determination process is greatly saved. For each temperature, determining a plurality of pulse currents corresponding to the corresponding temperature, and determining pulse time at the corresponding temperature based on the charge state interval and the pulse current corresponding to the target test curve at the corresponding temperature, wherein the pulse time is used for indicating the charge and discharge equipment to perform pulse test. In this way, the pulse time for the pulse test can be reflected in real time. And obtaining voltage change curves which are obtained by performing pulse test on the target battery by the charging and discharging equipment based on the pulse time and respectively correspond to the temperatures, wherein the voltage change curves represent the change conditions of the voltage along with the pulse current and the time. And performing parameter fitting through a pre-constructed equivalent circuit model based on the voltage change curves corresponding to the temperatures respectively to obtain parameters of a battery model corresponding to the target battery. Therefore, on the premise of saving time, the parameters of the battery model with high accuracy can be obtained, and the accuracy of the parameters of the battery model is greatly improved.

In one embodiment, as shown in fig. 6, determining a target test curve corresponding to each temperature based on a test curve obtained by performing multiple tests on a target battery at different temperatures by using a charging and discharging device includes:

step S602, for each temperature, under the condition that the current test frequency is the first test frequency, obtaining first test curves of a first number at the corresponding temperature; wherein the first number is determined by the first number of tests.

The test times are times of charging and discharging tests of the charging and discharging equipment on the electric core of the target battery, wherein for each temperature, one test time corresponds to a charging test curve and a discharging test curve.

Specifically, for each temperature, in the case that the current number of tests is the first number of tests, the computer device obtains a first number of first test curves at the corresponding temperature. For example, at 25 ℃, assuming that the first test number is 3 and the current test number is 3, the computer device acquires 6 first test curves at 25 ℃.

It should be noted that the first test curves may be a charging test curve in a charging process, or may be a discharging test curve in a discharging process, that is, at a temperature, two first test curves are added for each test, that is, the first test curves are the charging test curve in the charging process and the discharging test curve in the discharging process, respectively, that is, the first number is twice the number of the first tests under the condition that it is ensured that the temperature is not changed.

Step S604, for each temperature, determining a first capacity corresponding to each first test curve at the corresponding temperature, and determining whether a target capacity exists in the plurality of first capacities based on the first capacities corresponding to each first test curve at the corresponding temperature.

The first test curve may be a first charging test curve in a charging process or a first discharging test curve in a discharging process. The first capacity may be a first discharge capacity of a discharge process or a first charge capacity of a charge process. The target capacity may be a target discharge capacity of the discharge process or a target charge capacity of the charge process.

Specifically, for each temperature, the computer device determines first capacities corresponding to the first test curves at the corresponding temperature, determines whether a target charge capacity exists in the first charge capacities based on the first charge capacity of the first charge test curve representing the discharge process, and determines whether a target discharge capacity exists in the first discharge capacities based on the first discharge capacity of the first discharge test curve representing the charge process.

Step S606, for each temperature, under the condition that the target capacity does not exist in the plurality of first capacities, continuing to collect until the current number of tests is the second number of tests.

The second test frequency can be generally greater than or equal to 2, preferably the second test frequency can be 4, and the problem that the result is unstable due to too few test frequencies is avoided. Meanwhile, the problem that test time and resources are wasted due to excessive test times can be solved.

Specifically, for each temperature, under the condition that the target charging capacity does not exist in the plurality of first charging capacities and the target discharging capacity exists in the plurality of first discharging capacities, the collection is continued until the current test frequency is the second test frequency to determine the target charging capacity. Or, for each temperature, under the condition that the target charging capacity exists in the plurality of first charging capacities and the target discharging capacity does not exist in the plurality of first discharging capacities, continuing to collect the current time until the current test time is the second test time to determine the target discharging capacity. Or, for each temperature, under the condition that the target charging capacity does not exist in the plurality of first charging capacities and the target discharging capacity does not exist in the plurality of first discharging capacities, continuing to collect the current time until the current test time is the second test time, so as to determine the target charging capacity and the target discharging capacity.

Step S608, for each temperature, obtaining a second number of second test curves at the corresponding temperature; wherein the second number is determined by the second number of tests.

It should be noted that the first number of tests is smaller than the second number of tests. The second test curve may be a second charging test curve during charging or a second discharging test curve during discharging.

Step S610, for each temperature, determining a second capacity corresponding to each second test curve at the corresponding temperature, and determining a second capacity average value based on a plurality of second capacities.

The second test curve may be a second charging test curve in a charging process or a second discharging test curve in a discharging process. The second capacity may be a second discharge capacity of the discharging process and may also be a second charge capacity of the charging process. The second average capacity value may be a second average discharge capacity value of the discharging process or a second average charge capacity value of the charging process.

Specifically, for each temperature, under the condition of the discharge process and the corresponding temperature, the second discharge capacity corresponding to each second discharge test curve is determined. And the computer equipment performs average calculation on the second discharge capacity and determines the average value of the second discharge capacity. And for each temperature, determining second charging capacity corresponding to each second charging test curve respectively in the charging process and under the condition of the corresponding temperature. The computer device averages the second charge capacity and determines a second charge capacity average.

Step S612, for each temperature, comparing each second capacity at the corresponding temperature with the second capacity average value, respectively, to obtain a second capacity comparison result corresponding to each second capacity at the corresponding temperature.

Specifically, for each temperature, under the condition of the discharge process and the corresponding temperature, the computer equipment respectively compares each second discharge capacity with the average value of the second discharge capacities to obtain second discharge capacity comparison results respectively corresponding to each second discharge capacity in the discharge process and the corresponding temperature. For each temperature, under the condition of the charging process and the corresponding temperature, the computer equipment respectively compares each second charging capacity with the average value of the second charging capacity to obtain second charging capacity comparison results respectively corresponding to each second charging capacity in the charging process and the corresponding temperature.

And step S614, for each temperature, determining a target capacity from the plurality of second capacities based on the second capacity comparison result corresponding to each second capacity at the corresponding temperature, and using a second test curve corresponding to the target capacity as a target test curve at the corresponding temperature.

The target test curve may be a target charging test curve in a charging process or a target discharging test curve in a discharging process.

Specifically, in the case of the discharge process and the corresponding temperature, the computer device determines a discharge difference value between each second discharge capacity and an average value of the second discharge capacities based on a comparison result of the second discharge capacities corresponding to each second discharge capacity, and sets a second discharge capacity corresponding to a minimum discharge difference value as a target discharge capacity. And the computer equipment takes the second discharge test curve corresponding to the target discharge capacity as a target discharge test curve at a corresponding temperature. In the case of the charging process and the corresponding temperature, the computer device determines second charging differences of the respective second charging capacities from the second charging capacity average value, based on the second charging capacity comparison results corresponding to the respective second charging capacities, and takes the second charging capacity corresponding to the minimum second charging difference as the target charging capacity. And the computer equipment takes the second charging test curve corresponding to the target charging capacity as a target charging test curve at the corresponding temperature.

In this embodiment, for each temperature, when the current test frequency is the first test frequency, the first capacity of the first test curve is pre-determined, whether the target capacity exists in the first capacity can be quickly and effectively determined by the curve, and by performing coarse screening on each first test curve, additional tests can be avoided when the target capacity exists in the first capacity, thereby saving test time. And for each temperature, under the condition that the target capacity does not exist in the plurality of first capacities, and under the condition that the current test frequency is the second test frequency, judging the second capacity of the second test curve again. And combining the second capacity average value, and directly taking the second capacity with the minimum difference with the second capacity average value as the target capacity, so that the effectiveness and the accuracy of the target test curve are ensured.

In one embodiment, the determining whether the target capacity exists in the plurality of first capacities based on the first capacities corresponding to the respective first test curves at the respective temperatures includes: and determining a maximum value of the capacity, a minimum value of the capacity and a mean value of the first capacity based on the first capacity respectively corresponding to each first test curve at the corresponding temperature. And comparing the difference between the maximum capacity value and the minimum capacity value with the first average capacity value to obtain a difference comparison result. And determining that the target capacity exists in the plurality of first capacities when the difference comparison result is smaller than the difference threshold, and determining that the target capacity does not exist in the plurality of first capacities when the difference comparison result is larger than or equal to the difference threshold.

Specifically, for each temperature, the computer device determines a maximum charge capacity value, a minimum charge capacity value, and a first average charge capacity value based on the first charge capacities corresponding to the respective first charge test curves during the charging process and at the corresponding temperature. And the computer equipment subtracts the minimum value of the charging capacity from the maximum value of the charging capacity to obtain a first charging difference value, and subtracts the average value of the first charging capacity from the first charging difference value to obtain a charging difference value comparison result. And determining that the target charging capacity exists in the plurality of first charging capacities when the charging difference comparison result is less than the charging difference threshold, and determining that the target charging capacity does not exist in the plurality of first charging capacities when the charging difference comparison result is greater than or equal to the charging difference threshold.

For each temperature, in the discharging process and at the corresponding temperature, the computer equipment determines the maximum value of the discharging capacity, the minimum value of the discharging capacity and the average value of the first discharging capacity based on the first discharging capacities corresponding to the first discharging test curves respectively. And the computer equipment subtracts the minimum value of the discharge capacity from the maximum value of the discharge capacity to obtain a first discharge difference value, and subtracts the average value of the first discharge capacity from the first discharge difference value to obtain a discharge difference value comparison result. And determining that the target discharge capacity exists in the plurality of first discharge capacities when the discharge difference comparison result is smaller than a discharge difference threshold, and determining that the target discharge capacity does not exist in the plurality of first discharge capacities when the discharge difference comparison result is larger than or equal to the discharge difference threshold.

For example, at 25 ℃ and during discharge, the first test number is 3, and there are 3 first discharge capacities of the first discharge test curve. The computer equipment obtains a first discharge difference value by subtracting the discharge capacity minimum value from the discharge capacity maximum value based on the 3 first discharge capacities, the discharge capacity maximum value, the discharge capacity minimum value and the first discharge capacity average value. And the computer equipment subtracts the average value of the first discharge capacity from the first discharge difference value to obtain the capacity range difference of 3 times of tests. And if the capacity range is less than 1%, determining that the target discharge capacity exists, and stopping the test.

In this embodiment, the maximum value of the capacity, the minimum value of the capacity, and the average value of the first capacity are determined based on the first capacities corresponding to the respective first test curves at the respective temperatures. And the first capacity of the first test curve is pre-judged based on the maximum capacity value, the minimum capacity value and the average first capacity value, whether the target capacity exists in the first capacity can be quickly and effectively determined by the curve, and extra tests can be avoided by roughly screening each first test curve under the condition that the target capacity exists in the first capacity, so that the test time is saved.

In one embodiment, the method further comprises: for each temperature, in the case where there is a target capacity among the plurality of first capacities, an average value of the first capacities at the respective temperatures is determined based on the first capacities corresponding to the respective first test curves at the respective temperatures. And for each temperature, comparing each first capacity at the corresponding temperature with the average value of the first capacities at the corresponding temperature respectively to obtain a first capacity comparison result corresponding to each first capacity at the corresponding temperature. For each temperature, determining a target capacity from the plurality of first capacities based on a first capacity comparison result corresponding to the respective first capacity at the corresponding temperature, and using a first test curve corresponding to the target capacity as a target test curve at the corresponding temperature.

Specifically, for each temperature, in the case where the target discharge capacity exists in the first discharge capacities during the discharge process and at the corresponding temperature, the computer device performs an average calculation of the plurality of first discharge capacities to obtain an average value of the first discharge capacities. And the computer equipment compares the average value of each first discharge capacity with each first discharge capacity to obtain first discharge capacity comparison results respectively corresponding to each first discharge capacity. And the computer equipment determines that each first discharge capacity corresponds to a first discharge difference value respectively with the average value of the first discharge capacities based on the comparison result of the first discharge capacities, and takes the first discharge capacity corresponding to the minimum first discharge difference value as the target discharge capacity. And the computer equipment takes the first discharge test curve corresponding to the target discharge capacity as a target discharge test curve at a corresponding temperature.

For each temperature, the computer device performs an average calculation of the plurality of first charging capacities under the condition that the target charging capacity exists in the first charging capacities during the charging process and at the corresponding temperature, and obtains a first charging capacity average value. The computer device compares each average value of the first charging capacities with each first charging capacity to obtain a first charging capacity comparison result corresponding to each first charging capacity. The computer device determines, based on the first charging capacity comparison results, that each of the first charging capacities corresponds to a first charging difference value respectively from the first charging capacity average value, and sets, as a target charging capacity, a first charging capacity corresponding to a minimum of the first charging difference values. And the computer equipment takes the first charging test curve corresponding to the target charging capacity as a target charging test curve at a corresponding temperature.

In the present embodiment, in the case where it is determined that the target capacity exists in the first capacities, the first capacity average value is determined directly based on the first capacities. The first capacity with the minimum difference with the first capacity average value is directly used as the target capacity by combining the first capacity average value, so that the target test curve can be effectively and accurately determined without additionally carrying out multiple tests. On the basis of saving the testing time, the accuracy can be ensured, and the efficiency of the target testing curve is greatly improved.

In one embodiment, as shown in fig. 7, for each temperature, performing curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature includes:

step S702, for each temperature, determining a first derivative curve corresponding to the target test curve at the corresponding temperature by performing first derivative on the target test curve corresponding to the corresponding temperature.

Specifically, for each temperature, the computer device performs first derivation on the target test curve corresponding to the corresponding temperature through MATLAB, ORIGIN, or exocel software, and determines a first derivative curve corresponding to the target test curve at the corresponding temperature. For example, as shown in fig. 8, the first derivative curve is obtained by performing the first derivative on the target test curve shown in fig. 3 at 25 ℃.

Step S704, determining curve slope data corresponding to the target test curve at the corresponding temperature based on the first derivative curve corresponding to the target test curve at the corresponding temperature.

The curve slope data is slope values corresponding to all state intervals in the first-order wire curve respectively.

For each temperature, determining a state-of-charge interval corresponding to the target test curve at the respective temperature based on curve slope data corresponding to the target test curve at the respective temperature, comprising:

step S706, for each temperature, comparing the curve slope data corresponding to the target test curve at the corresponding temperature with a slope threshold to obtain a plurality of slope comparison results corresponding to the target test curve at the corresponding temperature.

Specifically, for each temperature, the computer device compares the slope data of the curve corresponding to the target test curve at the corresponding temperature with the slope threshold value, respectively, to obtain the slope comparison result corresponding to the target test curve at the corresponding temperature.

In step S708, for the plurality of slope comparison results corresponding to the target test curve at the corresponding temperature, the state of charge interval corresponding to the target test curve at the corresponding temperature is determined.

Specifically, the computer device characterizes the slope comparison result as a charge state corresponding to a large curvature slope change as a first charge state, and characterizes the slope comparison result as a charge state corresponding to a gentle curvature slope data change as a second charge state. The computer device determines a charge state interval for a first charge state from a first range of intervals and a charge interval for a second charge state from a second range of intervals. For example, the first charge state may be a charge state below 20%, or a charge state above 80%, and the second charge state may be a charge state between 20% and 80%. It should be noted that the first interval range is smaller than the second interval range. For example, the first interval range is less than 5%, and the second interval range is greater than or equal to 5%.

In the embodiment, the first-order derivation is performed on the target test curve, so that the curve slope data can be rapidly determined, the curve change condition of the target test curve can be accurately represented based on the curve slope data, the charge state interval matched with the curve change condition can be rapidly and effectively determined according to the curve change condition represented by the target test curve, and the time cost of the subsequent parameter determination process is greatly saved.

In one embodiment, for each temperature, the pulse time corresponding to each pulse current at the corresponding temperature is determined by a pulse time calculation formula based on the plurality of pulse currents corresponding to the corresponding temperature and the charge state interval corresponding to the corresponding temperature.

The pulse time t is calculated as follows:

where C is the rate of discharge and N is the charge state interval to be adjusted. For example, the charge state interval is 2%, the pulse rate is 3C (i.e., the pulse current 120Ah), and the pulse time is 24 s. For a 5% state-of-charge interval, a pulse rate of 3C (i.e., pulse current 120Ah), and a pulse time of 60 s.

In this embodiment, the pulse time can be adapted to the curve conditions based on the charge state interval that can faithfully reflect the target test curve conditions. Therefore, the voltage change curve with high accuracy and effectiveness can be obtained through the charge state interval and the pulse time which are matched with the target test curve.

In order to more clearly understand the technical solution of the present application, a more detailed embodiment is provided for description. Specifically, the following are:

the method comprises the following steps: the target test curve is determined, and the following description will be given by taking the discharge process as an example.

Specifically, for each temperature, under the condition that the current test times is the first test times, first test curves of a first number at the corresponding temperature are obtained. And determining a maximum value of the capacity, a minimum value of the capacity and a mean value of the first capacity based on the first capacity respectively corresponding to each first test curve at the corresponding temperature. And comparing the difference between the maximum capacity value and the minimum capacity value with the first average capacity value to obtain a difference comparison result. And determining that the target capacity exists in the plurality of first capacities when the difference comparison result is smaller than the difference threshold, and determining that the target capacity does not exist in the plurality of first capacities when the difference comparison result is larger than or equal to the difference threshold. For each temperature, under the condition that the target capacity does not exist in the plurality of first capacities, continuing to collect the temperature until the current test frequency is the second test frequency. For each temperature, a second number of second test curves at the corresponding temperature is obtained. For each temperature, determining a second capacity corresponding to each second test curve at the corresponding temperature, and determining a second capacity average value based on a plurality of second capacities. And for each temperature, comparing each second capacity at the corresponding temperature with the average value of the second capacities respectively to obtain a second capacity comparison result corresponding to each second capacity at the corresponding temperature. For each temperature, a target capacity is determined from the plurality of second capacities based on a second capacity comparison result corresponding to the respective second capacity at the corresponding temperature, and a second test curve corresponding to the target capacity is taken as a target test curve at the corresponding temperature.

For each temperature, in the case where the target capacity exists in the plurality of first capacities, an average value of the first capacities at the corresponding temperature is determined based on the first capacities corresponding to the respective first test curves at the corresponding temperature. And for each temperature, comparing each first capacity at the corresponding temperature with the average value of the first capacities at the corresponding temperature respectively to obtain a first capacity comparison result corresponding to each first capacity at the corresponding temperature. For each temperature, determining a target capacity from the plurality of first capacities based on a first capacity comparison result corresponding to the respective first capacity at the corresponding temperature, and using a first test curve corresponding to the target capacity as a target test curve at the corresponding temperature.

Step two: a charge state interval is determined.

Specifically, for each temperature, a first derivative curve corresponding to the target test curve at the corresponding temperature is determined by performing a first derivative on the target test curve corresponding to the corresponding temperature through MATLAB software or Origin software. And determining curve slope data corresponding to the target test curve at the corresponding temperature based on the first derivative curve corresponding to the target test curve at the corresponding temperature. And for each temperature, comparing the curve slope data corresponding to the target test curve at the corresponding temperature with a slope threshold value to obtain a plurality of slope comparison results corresponding to the target test curve at the corresponding temperature. For a plurality of slope comparisons corresponding to the target test curve at respective temperatures, a state of charge interval corresponding to the target test curve at the respective temperature is determined.

Step three: the pulse time is determined.

Specifically, for each temperature, a plurality of pulsed currents corresponding to the respective temperature is determined. For each temperature, determining pulse time corresponding to each pulse current at the corresponding temperature through a pulse time calculation formula based on the plurality of pulse currents corresponding to the corresponding temperature and the charge state interval corresponding to the corresponding temperature. And the computer equipment sends the pulse time and each pulse current respectively corresponding to each pulse current at the corresponding temperature to the charging and discharging equipment. And the charging and discharging equipment performs pulse testing based on the pulse time and the pulse current to obtain voltage change curves corresponding to all temperatures respectively.

Step four: based on the equivalent circuit model, parameters of the battery model are determined.

Specifically, a second-order equivalent circuit model is constructed based on a power supply, ohmic internal resistance, polarization resistance and polarization capacitance. And performing parameter fitting through a pre-constructed equivalent circuit model according to the voltage change curves corresponding to the temperatures respectively to obtain a parameter table containing parameters of the battery model corresponding to the target battery. For example, the parameter table may be a three-dimensional table, and the independent variables are charge state, temperature, and pulse current.

In addition, in order to verify the accuracy of the parameters of the cell model of the present application, the conventional HPPC method and the method of the present application were compared. As shown in fig. 9, the discharge simulation data after the conventional HPPC test (10% interval) and the second-order equivalent circuit model established after the sampling interval in this embodiment. The scheme adopted by the embodiment can ensure the accuracy of the acquired parameters.

In this embodiment, the target test curves respectively corresponding to the temperatures with high fidelity and accuracy can be determined through multiple tests. Whether curve change is gentle or not in the charging and discharging process can be clearly reflected by carrying out first-order derivation on the target test curve. Therefore, according to the curve change condition represented by the target test curve, the charge state interval matched with the curve change condition can be quickly and effectively determined, and the time cost of the subsequent parameter determination process is greatly saved. And pulse testing is performed based on the charge state interval with high adaptability, so that a voltage change curve with high accuracy can be obtained. Therefore, on the premise of saving time, the parameters of the battery model with high accuracy can be obtained, and the accuracy of the parameters of the battery model is greatly improved. In addition, compared to the conventional HPPC test method, in the present embodiment, it takes about 4-6 hours to test the pulse curve data at one temperature and one magnification, and a test period of about one day is required for testing different magnifications (for example, testing 4 different magnifications) at a certain temperature, whereas for the conventional HPPC test method, if the test temperature is not 25 ℃, the charge state needs to be adjusted again to 25 ℃ each time, and then adjusted to the response temperature to perform pulse discharge tests at different magnifications (different magnifications can be tested at the same time), so that the test period is very long when the conventional HPPC test method tests different SOCs at a certain temperature, and the charge state is adjusted while the discharge pulse is adopted in the present embodiment, and the adjustment is not required to return to the normal temperature, so that the temperature adaptation time is saved, that is, the test period is greatly shortened, and the test accuracy is improved.

It should be understood that, although the steps in the flowcharts related to the embodiments as described above are sequentially displayed as indicated by arrows, the steps are not necessarily performed sequentially as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a part of the steps in the flowcharts related to the embodiments described above may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the execution order of the steps or stages is not necessarily sequential, but may be rotated or alternated with other steps or at least a part of the steps or stages in other steps.

Based on the same inventive concept, the embodiment of the present application further provides an apparatus for acquiring battery model parameters, which is used for implementing the method for acquiring battery model parameters. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so that specific limitations in the following embodiment of the device for acquiring one or more battery model parameters may refer to the limitations in the above method for acquiring the battery model parameters, and are not described herein again.

In one embodiment, as shown in fig. 10, there is provided a battery model parameter obtaining apparatus, including: a first determination module 1002, a recognition module 1004, a second determination module 1006, a third determination module 1008, an acquisition module 1010, and a fitting module 1012, wherein:

the first determining module 1002 is configured to obtain a test curve based on multiple tests performed on a target battery at different temperatures by a charging and discharging device, and determine a target test curve corresponding to each temperature; wherein the target test curve characterizes a change in voltage with a change in state of charge during the test.

The identifying module 1004 is configured to, for each temperature, perform curve slope identification on the target test curve corresponding to the corresponding temperature to obtain curve slope data corresponding to the target test curve at the corresponding temperature.

A second determining module 1006, configured to determine, for each temperature, a state-of-charge interval corresponding to the target test curve at the corresponding temperature based on the curve slope data corresponding to the target test curve at the corresponding temperature, wherein the state-of-charge interval represents an adjustment value of a state of charge during the pulse test.

A third determining module 1008, configured to determine, for each temperature, a plurality of pulse currents corresponding to the corresponding temperature, and determine, based on the charge state interval and the pulse current corresponding to the target test curve at the corresponding temperature, a pulse time at the corresponding temperature, where the pulse time is used to instruct the charging and discharging device to perform a pulse test.

The obtaining module 1010 is configured to obtain voltage variation curves which are obtained by performing a pulse test on the target battery by the charging and discharging device based on the pulse time and respectively correspond to the temperatures, and the voltage variation curves represent the variation conditions of the voltage along with the pulse current and the time.

A fitting module 1012, configured to perform parameter fitting through a pre-constructed equivalent circuit model based on the voltage change curves corresponding to the respective temperatures, to obtain parameters of a battery model corresponding to the target battery.

In one embodiment, the first determining module 1002 is configured to, for each temperature, obtain a first number of first test curves at the corresponding temperature when the current test time is a first test time; wherein the first number is determined by the first number of tests. For each temperature, determining first capacities corresponding to the first test curves at the corresponding temperature, and judging whether the target capacity exists in the plurality of first capacities based on the first capacities corresponding to the first test curves at the corresponding temperature. For each temperature, under the condition that the target capacity does not exist in the plurality of first capacities, continuing to collect the temperature until the current test frequency is the second test frequency. For each temperature, obtaining a second number of second test curves at the corresponding temperature; wherein the second number is determined by the second number of tests. For each temperature, determining a second capacity corresponding to each second test curve at the corresponding temperature, and determining a second capacity average value based on a plurality of second capacities. And for each temperature, comparing each second capacity at the corresponding temperature with the average value of the second capacities respectively to obtain a second capacity comparison result corresponding to each second capacity at the corresponding temperature. For each temperature, a target capacity is determined from the plurality of second capacities based on a second capacity comparison result corresponding to the respective second capacity at the corresponding temperature, and a second test curve corresponding to the target capacity is taken as a target test curve at the corresponding temperature.

In one embodiment, the first determining module 1002 is configured to determine a maximum capacity value, a minimum capacity value, and a first average capacity value based on the first capacities corresponding to the respective first test curves at the respective temperatures. And comparing the difference between the maximum capacity value and the minimum capacity value with the first average capacity value to obtain a difference comparison result. And determining that the target capacity exists in the plurality of first capacities when the difference comparison result is smaller than the difference threshold, and determining that the target capacity does not exist in the plurality of first capacities when the difference comparison result is larger than or equal to the difference threshold.

In one embodiment, the first determining module 1002 is configured to determine, for each temperature, a first average value of the capacities at the corresponding temperature based on the first capacities corresponding to the respective first test curves at the corresponding temperature in a case where the target capacity exists among the plurality of first capacities. And for each temperature, comparing each first capacity at the corresponding temperature with the average value of the first capacities at the corresponding temperature respectively to obtain a first capacity comparison result corresponding to each first capacity at the corresponding temperature. For each temperature, a target capacity is determined from the plurality of first capacities based on a first capacity comparison result corresponding to the respective first capacity at the corresponding temperature, and a first test curve corresponding to the target capacity is taken as a target test curve at the corresponding temperature.

In one embodiment, the identifying module 1004 is configured to determine, for each temperature, a first derivative curve corresponding to the target test curve at the corresponding temperature by performing a first derivative on the target test curve corresponding to the corresponding temperature. And determining curve slope data corresponding to the target test curve at the corresponding temperature based on the first derivative curve corresponding to the target test curve at the corresponding temperature. And for each temperature, comparing the curve slope data corresponding to the target test curve at the corresponding temperature with a slope threshold value to obtain a plurality of slope comparison results corresponding to the target test curve at the corresponding temperature. For a plurality of slope comparisons corresponding to the target test curve at the respective temperatures, a state-of-charge interval corresponding to the target test curve at the respective temperatures is determined.

In one embodiment, the third determining module 1008 is configured to determine, for each temperature, a pulse time corresponding to each pulse current at the corresponding temperature through a pulse time calculation formula based on the plurality of pulse currents corresponding to the corresponding temperature and the state of charge interval corresponding to the corresponding temperature.

The modules in the device for acquiring the battery model parameters can be wholly or partially realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as shown in fig. 11. The computer device includes a processor, a memory, an Input/Output interface (I/O for short), and a communication interface. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface is connected to the system bus through the input/output interface. 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, a computer program, and a database. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The database of the computer device is used for storing the acquired data of the battery model parameters. The input/output interface of the computer device is used for exchanging information between the processor and an external device. The communication interface of the computer device is used for connecting and communicating with an external terminal through a network. The computer program is executed by a processor to implement a method of obtaining parameters of a battery model.

Those skilled in the art will appreciate that the architecture shown in fig. 11 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is further provided, which includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method embodiments when executing the computer program.

In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

In an embodiment, a computer program product is provided, comprising a computer program which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, database, or other medium used in the 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 (MRAM), Ferroelectric Random Access Memory (FRAM), Phase Change Memory (PCM), graphene Memory, and the like. Volatile Memory can include Random Access Memory (RAM), external cache Memory, and the like. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others. The databases referred to in various embodiments provided herein may include at least one of relational and non-relational databases. The non-relational database may include, but is not limited to, a block chain 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 devices, quantum computing based data processing logic devices, etc., without limitation.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for obtaining parameters of a battery model is characterized by comprising the following steps:

2. The method of claim 1, wherein determining the target test curves corresponding to the respective temperatures based on the test curves obtained by performing a plurality of tests on the target battery at different temperatures by the charging and discharging device comprises:

for each temperature, under the condition that the current test times are first test times, obtaining first test curves of a first number at the corresponding temperature; wherein the first number is determined by the first number of tests;

for each temperature, determining first capacities corresponding to the first test curves at the corresponding temperature respectively, and judging whether a target capacity exists in the first capacities based on the first capacities corresponding to the first test curves at the corresponding temperature respectively;

for each temperature, under the condition that the target capacity does not exist in the plurality of first capacities, continuously collecting until the current test frequency is the second test frequency;

for each temperature, obtaining a second number of second test curves at the corresponding temperature; wherein a second number is determined by the second number of tests;

for each temperature, determining second capacities corresponding to the second test curves at the corresponding temperature respectively, and determining a second capacity average value based on the plurality of second capacities;

for each temperature, comparing each second capacity at the corresponding temperature with the average value of the second capacities respectively to obtain a second capacity comparison result corresponding to each second capacity at the corresponding temperature;

for each temperature, determining a target capacity from a plurality of second capacities based on a second capacity comparison result corresponding to the respective second capacities at the respective temperatures, and using a second test curve corresponding to the target capacity as a target test curve at the respective temperature.

3. The method of claim 2, wherein determining whether a target capacity exists in the plurality of first capacities based on the first capacities corresponding to the respective first test curves at the respective temperatures comprises:

determining a maximum value of the capacity, a minimum value of the capacity and a first average value of the capacity based on the first capacity respectively corresponding to each first test curve at the corresponding temperature;

comparing the difference between the maximum capacity value and the minimum capacity value with the first average capacity value to obtain a difference comparison result;

and determining that the target capacity exists in the plurality of first capacities when the difference comparison result is smaller than the difference threshold, and determining that the target capacity does not exist in the plurality of first capacities when the difference comparison result is larger than or equal to the difference threshold.

4. The method of claim 2, further comprising:

for each temperature, determining a first capacity average value at the corresponding temperature based on the first capacities corresponding to the respective first test curves at the corresponding temperature under the condition that the target capacity exists in the plurality of first capacities;

for each temperature, comparing each first capacity at the corresponding temperature with the average value of the first capacities at the corresponding temperature respectively to obtain a first capacity comparison result corresponding to each first capacity at the corresponding temperature;

for each temperature, determining a target capacity from the plurality of first capacities based on a first capacity comparison result corresponding to the respective first capacity at the corresponding temperature, and using a first test curve corresponding to the target capacity as a target test curve at the corresponding temperature.

5. The method of claim 1, wherein for each temperature, identifying a slope of the target test curve corresponding to the respective temperature to obtain slope data corresponding to the target test curve at the respective temperature comprises:

for each temperature, determining a first derivative curve corresponding to the target test curve at the corresponding temperature by performing first derivative on the target test curve corresponding to the corresponding temperature;

determining curve slope data corresponding to the target test curve at the corresponding temperature based on the first derivative curve corresponding to the target test curve at the corresponding temperature;

for each temperature, comparing curve slope data corresponding to the target test curve at the corresponding temperature with a slope threshold value to obtain a plurality of slope comparison results corresponding to the target test curve at the corresponding temperature;

for a plurality of slope comparisons corresponding to the target test curve at respective temperatures, a state of charge interval corresponding to the target test curve at the respective temperature is determined.

6. The method of claim 1, wherein determining the pulse time at the respective temperature based on the charge state interval, the pulse current, corresponding to the target test curve at the respective temperature comprises:

and for each temperature, determining the pulse time corresponding to each pulse current at the corresponding temperature through a pulse time calculation formula based on the plurality of pulse currents corresponding to the corresponding temperature and the charge state interval corresponding to the corresponding temperature.

7. An apparatus for obtaining parameters of a battery model, the apparatus comprising:

the first determining module is used for obtaining a test curve based on multiple tests of the target battery at different temperatures by the charging and discharging equipment, and determining target test curves corresponding to the temperatures respectively; wherein the target test curve represents the situation that the voltage changes along with the change of the charge state in the test process;

the identification module is used for identifying the slope of the curve of the target test curve corresponding to the corresponding temperature for each temperature to obtain the slope data of the curve corresponding to the target test curve at the corresponding temperature;

a second determining module, configured to determine, for each temperature, a charge state interval corresponding to the target test curve at the corresponding temperature based on curve slope data corresponding to the target test curve at the corresponding temperature, where the charge state interval represents an adjustment value of a charge state during a pulse test;

the third determining module is used for determining a plurality of pulse currents corresponding to corresponding temperatures for each temperature, and determining pulse time at the corresponding temperatures based on the charge state intervals and the pulse currents corresponding to the target test curves at the corresponding temperatures, wherein the pulse time is used for indicating the charging and discharging equipment to perform pulse tests;

the acquisition module is used for acquiring voltage change curves which are obtained by performing pulse test on the target battery through the charging and discharging equipment based on the pulse time and respectively correspond to the temperatures, and the voltage change curves represent the change conditions of the voltage along with the pulse current and the time;

and the fitting module is used for performing parameter fitting through a pre-constructed equivalent circuit model based on the voltage change curves respectively corresponding to the temperatures to obtain parameters of the battery model corresponding to the target battery.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method of any of claims 1 to 6.

9. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that the computer program realizes the steps of the method of any one of claims 1 to 6 when executed by a processor.