CN112083336A - Lithium ion battery pack electrochemical model parameter acquisition method - Google Patents

Lithium ion battery pack electrochemical model parameter acquisition method Download PDF

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CN112083336A
CN112083336A CN202011117166.3A CN202011117166A CN112083336A CN 112083336 A CN112083336 A CN 112083336A CN 202011117166 A CN202011117166 A CN 202011117166A CN 112083336 A CN112083336 A CN 112083336A
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battery
lithium ion
discharge
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battery pack
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CN112083336B (en
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李俊夫
于瀚卿
杨龙
于全庆
王宇海
楚潇
任陆宁
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Harbin Institute of Technology Weihai
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    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/367—Software therefor, e.g. for battery testing using modelling or look-up tables
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
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Abstract

The invention provides a lithium ion battery pack electrochemical model parameter acquisition method, which is characterized in that a voltage curve of a discharging tail end of different individual batteries under an identification working condition is contrastively analyzed based on excitation response analysis, the discharging capacity corresponding to each single battery under the identification working condition is estimated, and the terminal voltage of a resting tail end in the identification working condition is extracted, so that the relevant parameters of the electrochemical model basic working process of different single batteries are identified, further, other parameters are acquired, the application of the electrochemical model on a battery pack is realized, and meanwhile, technical support is provided for simplifying the application of the electrochemical model in a battery management system, such as charge state estimation, health state estimation and the like.

Description

Lithium ion battery pack electrochemical model parameter acquisition method
Technical Field
The invention relates to the field of lithium ion battery pack electrochemical model parameter identification, in particular to a battery pack electrochemical model parameter acquisition method.
Background
The lithium ion battery is widely concerned in various fields as an excellent energy storage device, the health condition of the battery can be more accurately evaluated by accurately acquiring internal parameters of the battery, and the lithium ion battery has important significance for implementing effective battery health management and improving the reliability and safety of battery use.
Part of the inventors of the present invention participated in the development of the following applications: CN201810559026.8, name: the invention discloses a method for acquiring electrochemical model parameters of a lithium ion battery, which provides a rapid and nondestructive method for acquiring electrochemical model parameters of a single battery without an electrochemical measurement method or an intelligent algorithm, and simultaneously realizes the simulation analysis of the change of the battery end voltage and the shell temperature along with the time. The lithium ion battery electrochemical model can accurately describe the complicated reaction process in the battery, and can accurately simulate the internal and external characteristics of the battery, but the model structure is more complicated, the calculation amount is large, the quantity of the model parameters is more, the battery parameters are difficult to accurately obtain, especially after the battery pack is formed by the single batteries, the consistency problem among the single batteries is exposed, so that under the same current excitation condition, different voltage responses can be generated by the single batteries, and further, the problem of inaccurate test of the battery discharge capacity due to incomplete voltage test data exists, and all the single battery model parameters cannot be accurately obtained.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an electrochemical model parameter acquisition method suitable for a lithium ion battery pack.
The technical scheme adopted by the invention for solving the defects of the prior art is as follows: in order to solve the problem that the discharge voltage of each single battery in the battery pack is not synchronous in the last discharge stage of the battery pack, a capacity approximate compensation method is adopted, namely, according to the discharge voltage curve of the single battery which discharges the electricity most quickly in the battery pack, capacity compensation is carried out on the rest monomers which do not discharge electricity, the total capacity of the monomers is respectively determined, and then model parameter distribution identification is carried out.
The specific identification steps are as follows:
step one, establishing an electrochemical model of a lithium ion battery pack; applying a parameter identification working condition to the lithium ion battery pack to charge and discharge the lithium ion battery, and obtaining voltage data and current data of each single battery in the lithium ion battery pack under the charging and discharging conditions; and step three, obtaining model parameters of each single battery of the lithium ion battery pack according to the lithium ion battery pack electrochemical model and the voltage data and the current data of the single batteries of the lithium ion battery pack under the charging and discharging conditions.
Further, the lithium ion battery cell electrochemical model comprises an open circuit voltage Eocv(t) positive electrode active particle surface intercalation lithium concentration fraction ysurf(t) negative electrode active particle surface lithium intercalation concentration fraction xsurf(t) concentration polarization overpotential ηcon-polarization(t) reaction polarization overpotential ηact-polarization(t), ohmic polarization overpotential ηohm-polarization(t) and terminal voltage Uapp(t)。
Further, voltage data and current data of the single batteries are obtained, and the discharge capacity Q corresponding to the single battery with the fastest discharge speed is calculated by adopting an ampere-hour integration methodallObtaining a battery state of charge (SOC) sequence according to a formula (1), extracting the terminal voltage of the laying terminal,
Figure BDA0002730709770000021
fitting the unknown parameters according to equation (2):
Eocv＝Up[y0+Dy(1-soc)]-Un[x0-Dx(1-soc)] (2)
wherein SOC is the state of charge SOC of the battery, I is the external current, the discharging is specified to be positive, and the charging is specified to be negative; y is0And x0Initial rate of lithium intercalation for positive and negative electrodes, DyAnd DxThe variation range of the initial lithium intercalation rate of the anode and the cathode; positive and negative open circuit potential curve Up、UnIs a known function.
The total discharge capacity of the incompletely discharged cells was calculated: for the battery monomer with the discharge voltage not reduced to the cut-off voltage, comparing the cut-off voltages of the incompletely discharged battery monomer and the completely discharged battery monomer, and determining the electric quantity delta Q which can still be discharged when the completely discharged battery monomer stops discharging by adopting a model simulation-based binary iteration calculation method, wherein the total capacity of the incompletely discharged battery monomer is equal to the electric quantity delta Q and the electric quantity Q which are not dischargedallThe specific implementation process of determining the Δ Q by applying the binary iterative computation method is as follows:
(1) firstly, the voltage of the ith single battery which is not completely discharged when the discharge of the whole battery pack is cut off is obtained and is marked as UiThe discharge performance of the single battery is theoretically consistent with that of the single battery with the fastest discharge, and the slave U is intercepted from the battery data of the single battery with the fastest dischargeiThe prior discharge capacity compensation value corresponding to the cut-off voltage of 2.75V is recorded as delta Qi；
(2) Will be delta QiAnd QallAdding to obtain the total prior discharge capacity of the incompletely discharged single battery, and recording as Qall_i；
(3) Total capacity Q of discharge priorall_iSubstituting the equation (1), obtaining SOC at different moments by using an ampere-hour integral method, and further obtaining a basic working process parameter y of the battery by using an LSF fitting method0、x0、Dy、DxCalculating the positive and negative electrode capacities Q according to the formula (3)pAnd Qn；
Figure BDA0002730709770000022
(4) Under the condition of a given current I, performing voltage simulation on the single battery by using a formula (2), intercepting the time corresponding to the voltage discharge of the battery from full charge to cut-off voltage, and then acquiring the total simulated discharge capacity Q by using an ampere-hour integration methodall_i’；
(5) Comparing the prior total discharge capacity Qall_iAnd total capacity Q of simulated dischargeall_i' if the difference between the two is greater than a given value of 0.01A · s, the mean of the two is taken and then assigned to Qall_iAssigning the optimized Qall_iSubstituting the formula (1), and repeating the steps (3) to (5) until the total prior discharge capacity Qall_iAnd total capacity Q of simulated dischargeall_i' the difference is less than a given value.
The invention has the beneficial effects that: under the condition that the discharge behaviors of the single batteries in the battery pack are not consistent, a parameter acquisition method suitable for the battery pack is provided based on the existing single battery electrochemical model. The method can realize accurate, lossless and quick acquisition of the battery pack and the internal battery monomer model parameters thereof, thereby meeting the simulation precision requirement of the terminal voltage of the battery pack.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a current excitation for a parameter identification condition;
fig. 2 is a battery pack external characteristic response curve;
FIG. 3 is a secondary optimization estimation method for capacity parameters of incompletely discharged single batteries;
FIG. 4 is resting end voltage data for a cell;
FIGS. 5-10 show the simulation results of No. 1-6 batteries under the constant current discharge condition of 0.25C, respectively;
FIG. 11 shows simulation results of the battery pack under a constant current discharge condition of 0.25C;
FIGS. 12-17 show simulation results of batteries No. 1-6 under a constant current discharge condition of 0.5C, respectively;
FIG. 18 shows simulation results of the battery pack under a 0.5C constant current discharge condition;
FIGS. 19-24 show simulation results of No. 1-6 batteries under 1C constant current discharge conditions, respectively;
FIG. 25 shows simulation results of the battery pack under 1C constant current discharge conditions;
fig. 26 shows the voltage simulation result under the complete operating condition of the battery pack.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In order to solve the problem of consistency of single batteries in the battery pack, the current excitation working condition shown in fig. 1 is adopted, but when the battery cut-off condition is set, the voltage of the battery pack is updated: unlike the single battery, when discharging to 18V at a constant current of 1C, the battery was left for 10min, and then the battery was subjected to constant current discharge of 0.02C to a full set cut-off voltage of 17V. The external characteristic response curve of the battery pack is shown in fig. 2.
The lithium ion battery pack electrochemical model parameter acquisition method of the invention is based on a single lithium ion battery electrochemical model as follows:
Figure BDA0002730709770000031
wherein, UappThe terminal voltage of the lithium ion battery is the difference between solid phase potentials of two boundaries of positive and negative electrodes of the lithium ion battery close to a current collector;
Up、Unpositive and negative open circuit potentials;
t is time, t+Is the cation transference number;
ysurfand xsurfThe lithium ion concentration on the solid phase surface of the positive electrode and the negative electrode;
r is an ideal gas constant;
f is a Faraday constant;
t is the working temperature of the lithium ion battery, and the value is a constant value of 25 ℃ without considering the influence of the temperature on the battery behavior;
c0is the first in the electrolyteStarting lithium ion concentration;
mpand mnIs an intermediate variable and has no specific physical meaning;
△c1and Δ c2Is the concentration of lithium ions at the positive and negative electrode current collectors relative to the initial lithium ion concentration c in the electrolyte0The amount of change of (d);
Rohmthe equivalent ohmic internal resistance of the lithium ion battery;
i is the external current, which specifies positive discharge and negative charge.
Because the battery pack adopts a series connection mode, the total voltage U of the battery packapp_packEqual to the sum of the voltages of the single batteries connected in series, and the calculation formula of the terminal voltage of the battery pack is as follows:
Figure BDA0002730709770000041
wherein i is the number of the single batteries of the series battery pack, Uapp_cell_iIs the terminal voltage of the i-th battery.
In order to simulate the terminal voltage behavior of the battery pack, parameters in the single battery model need to be acquired, and then the simulated voltages of the single batteries are summed to obtain a group of terminal voltage behaviors.
The lithium ion battery pack is formed by connecting each battery monomer in series, so the voltage of the battery pack is the sum of the voltages of all the monomers. The lithium ion battery cell is used as a system for analysis, and input variables and output variables of the system are respectively as follows: charge and discharge current and battery terminal voltage. The behavior description of the lithium ion battery is to give the magnitude of the terminal voltage under different external current conditions, and the essence of the lithium ion battery can be described as follows: the physical and chemical processes in the lithium ion battery are comprehensively carried out, and under the condition that the external current is I, the difference of solid phase potentials of two boundaries of the positive and negative electrodes close to a current collector is the terminal voltage UappTo what is the value taken.
Terminal voltage U of lithium ion battery monomerappOne way of calculating equivalence to equation (4) is as follows:
Uapp(t)＝Eocv(t)-ηcon-polarization(t)-ηact-polarization(t)-ηohm-polarization(t) (6)
the terminal voltage can be decomposed into an ideal electromotive force and three-part overpotential: concentration polarization overpotential, reaction polarization overpotential, and ohmic polarization overpotential.
1. Basic working process and parameter identification step
1.1 when the battery pack reaches a predetermined discharge cutoff voltage due to the difference of the individual batteries in the battery pack, the individual voltages are not uniform, but there is inevitably a case where a certain battery first reaches the discharge cutoff voltage of 2.75V or less, and the battery voltage data is sufficient for all data necessary for parameter identification according to the parameter identification process developed in the past. For other batteries whose discharge voltage is not reduced to 2.75V, the voltage test data is not enough to complete the data required for identifying the four basic parameters, so that the capacity of the battery cell which is not completely discharged needs to be checked.
The scheme defaults that the battery screening work is completed in the battery grouping process, the performances of all single batteries in the battery pack are basically close, therefore, the discharge characteristics of different single batteries at the discharge tail end can be assumed to be completely the same, and the battery single battery which is not completely discharged and the electric quantity delta Q which can still be discharged when the whole battery pack stops discharging can be determined by comparing the cut-off voltages of the incompletely discharged battery and the completely discharged battery. Calculating the discharge capacity corresponding to the completely discharged single battery according to an ampere-hour integration method, and recording as Qall_0For the incompletely discharged battery, the unreleased electric quantity Δ Q obtained in the first step is added as the total capacity Q of the ith batteryall_i。
The invention adopts a binary iteration calculation method based on model simulation to carry out Q on the estimated productall_iSecondary optimization is performed to ensure the accuracy of the capacity compensation strategy, and 5 parameters Q are identified by using the voltage test result in FIG. 3all、y0、x0、QpAnd QnThe identification steps are as follows:
(1) firstly, an ith section which is not completely discharged when the discharge of the whole battery pack is cut off is obtainedBulk cell voltage, denoted as UiThe discharge performance of the single battery is theoretically consistent with that of the single battery with the fastest discharge, and the slave U is intercepted from the battery data of the single battery with the fastest dischargeiThe prior discharge capacity compensation value corresponding to the cut-off voltage of 2.75V is recorded as delta Qi；
(2) Will be delta QiAnd QallAdding to obtain the total prior discharge capacity of the incompletely discharged single battery, and recording as Qall_i；
(3) Total capacity Q of discharge priorall_iSubstituting the equation (1), obtaining SOC at different moments by using an ampere-hour integral method, and further obtaining a basic working process parameter y of the battery by using an LSF fitting method0、x0、Dy、DxCalculating the positive and negative electrode capacities Q according to the formula (3)pAnd Qn；
Figure BDA0002730709770000051
(4) Under the condition of a given current I, performing voltage simulation on the single battery by using a formula (2), intercepting the time corresponding to the voltage discharge of the battery from full charge to cut-off voltage, and then acquiring the total simulated discharge capacity Q by using an ampere-hour integration methodall_i’；
(5) Comparing the prior total discharge capacity Qall_iAnd total capacity Q of simulated dischargeall_i' if the difference between the two is greater than a given value of 0.01A · s, the mean of the two is taken and then assigned to Qall_iAssigning the optimized Qall_iSubstituting the formula (1), and repeating the steps (3) to (5) until the total prior discharge capacity Qall_iAnd total capacity Q of simulated dischargeall_i' the difference is less than a given value.
Next, extracting the terminal voltage of each single battery at the resting end in the identification working condition, and fitting the parameter y in the formula 5 by using an LSF method0，x0，Dx，DyQ is obtained according to equation 3pAnd Qn. The voltage data required to fit the above cell parameters are shown in red dot notation in fig. 4.
Wherein, the open circuit potential curve U of the positive and negative electrodesp、UnFor a known function, the functional form is as follows:
Figure BDA0002730709770000052
Figure BDA0002730709770000061
1.2 extracting the change value delta U of the battery terminal voltage when applying current excitation, and utilizing the directly assigned ohmic internal resistance RohmCalculating reaction polarization overpotential eta by using external current Iact-polarizationFitting by using an LSF method according to the following formula to obtain a reaction polarization coefficient Pact：
Figure BDA0002730709770000062
Figure BDA0002730709770000063
Wherein R is an ideal gas constant, F is a Faraday constant, c0Is the initial lithium ion concentration in the electrolyte, T is the operating temperature of the lithium ion battery, mpAnd mnIs an intermediate variable, has no specific physical meaning, c0Is the initial lithium ion concentration, P, in the electrolyteactThe polarization coefficient is reflected.
1.3 to ensure the model has better simulation precision, the parameter value R is set based on the prior experienceohm，τe，c0，τp，τn，Pcon_a，Pcon_bIs constant, and the model parameters of different single batteries have the same value, respectively 0.03 omega, 100s and 1000mol/m3，10s，10s，950mol/(A·m3)，500mol/(A·m3)。
2. Experimental procedure
The battery test equipment used in the invention is a 60V-20A battery charge and discharge tester produced by New Wille electronics Limited of Shenzhen, and the voltage precision and the current precision of the tester are one thousandth.
2.1 battery pack model parameter acquisition steps are as follows:
a) the design identification condition is shown in fig. 1, and a discharge voltage curve of the battery pack under the condition is obtained, as shown in fig. 2.
b) The total capacity Q of each single battery of the battery pack is obtained by utilizing a time safety integration method and combining with the battery capacity compensationallEstimating four parameters y of the basic working process of each single battery by using a least square method0，x0，QpAnd Qn；
c) Extracting the change value of the terminal voltage of each single battery when current excitation is applied, and utilizing the directly assigned ohmic internal resistance RohmCalculating reaction polarization overpotential eta by using external current Iact-polarizationtPerforming least square fitting according to the formulas (8) and (9) to estimate the reaction polarization parameter P of each single batteryact；
d) Due to the parameter Rohm，τe，c0，τp，τn，Pcon_a，Pcon_bDifferent battery cells do not change much, so the battery cells are directly assigned on the basis of a large number of experiments.
2.2 Voltage simulation with Single cell
After obtaining the parameters of the single battery, firstly carrying out voltage simulation on the single battery, wherein the simulation calculation steps are as follows: a) four basic parameters y obtained by identification0，x0，QpAnd QnAnd calculating the average lithium ion concentration of the anode solid phase and the cathode solid phase according to the following calculation formula:
yavg(t)＝y0+I(t)t/Qp，xavg(t)＝x0-I(t)t/Qn (11)
wherein t is time, yavgAnd xavgThe average lithium ion concentration of the positive and negative solid phases. For calculating the open-circuit voltage E of the lithium ion batteryocvCalculation of lithium on the solid-phase surface of the positive and negative electrodesIon concentration ysurf、xsurfTheir average lithium ion concentration yavg、xavgAre denoted as Δ y and Δ x, respectively, and the relationship between the above variables is as follows:
ysurf(t)＝yavg(t)+Δy(t) (12)
xsurf(t)＝xavg(t)-Δx(t) (13)
the calculated equations for Δ y and Δ x are as follows:
Figure BDA0002730709770000071
wherein, taupAnd τnThe time constants of solid phase diffusion of the positive electrode and the negative electrode are, delta y 'and delta x' are intermediate variables, the initial values of the intermediate variables are 0, and the iterative calculation form is as follows:
Figure BDA0002730709770000072
Figure BDA0002730709770000073
calculating to obtain the open circuit potential U of the anode and the cathode according to the following formulapAnd Un
Figure BDA0002730709770000074
Figure BDA0002730709770000075
The open circuit voltage E is then obtained according to the following equationocv
Eocv(t)＝Up(ysurf(t))-Un(xsurf(t)) (19)
b) According to ohm's law, combined with set ohmic internal resistance RohmComputing ohmic poleOverpotential ηohm-polarizationThe calculation formula is as follows:
ηohm-polarization(t)＝RohmI(t) (20)
c) according to the set parameter Pcon_a，Pcon_bCalculating the lithium ion concentration at the positive and negative electrode current collectors with respect to the initial lithium ion concentration c in the electrolyte0Change amount Δ c of1And Δ c2The calculation process is as follows:
Figure BDA0002730709770000076
Figure BDA0002730709770000077
wherein, Δ c1And Δ c2Has an initial value of 0. When calculating to obtain deltac1And Δ c2Then, the concentration polarization overpotential eta can be obtainedcon-polarizationThe calculation formula of (A) is as follows:
Figure BDA0002730709770000078
d) obtaining a parameter P according to the identificationactAnd Δ c obtained in the previous step1And Δ c2Calculating the reaction polarization overpotential eta using the following formulaact-polarization。
Figure BDA0002730709770000081
Figure BDA0002730709770000082
Wherein R is an ideal gas constant, F is a Faraday constant, c0Is the initial lithium ion concentration in the electrolyte, T is the operating temperature of the lithium ion battery, mpAnd mnIs an intermediate variable, without specific physical significance,. DELTA.c1And Δ c2Is the concentration of lithium ions at the positive and negative electrode current collectors relative to the initial lithium ion concentration c in the electrolyte0The amount of change of (d); pactIs a reaction polarization coefficient;
based on the steps, the terminal voltage U of the lithium ion battery monomerapp_cell_iThe calculation can be made with reference to equation 3. After the voltages of the single batteries are respectively calculated, the voltages are added up to obtain the whole group of voltage Uapp_packAnd (5) simulation results.
3 Experimental verification
The invention carries out simulation verification on the battery made of the lithium iron phosphate anode material, the battery pack adopts a 6-section one-string configuration mode, and the serial numbers of the 6-section batteries are respectively 1-6. And comparing the voltage obtained by model simulation and the voltage obtained by test measurement under the constant current discharge working conditions of 0.25C, 0.5C and 1C, as shown in the attached figures 5-26.
The invention provides a corresponding solution for the problem that the existing electrochemical model can not be accurately simulated in a battery pack, namely a battery pack model parameter acquisition method based on excitation response analysis is provided, voltage curves of discharging terminals of different individual batteries under an identification working condition are contrastively analyzed, discharging capacity corresponding to the identification working condition is estimated, terminal voltage of a laying terminal is extracted, so that relevant parameters of basic working processes of electrochemical models of different single batteries are identified, further acquisition of other parameters is implemented, application of the electrochemical model to the battery pack is realized, and technical support is provided for simplifying application of the electrochemical model in a battery management system, such as charge state estimation, health state estimation and the like.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. A lithium ion battery pack electrochemical model parameter acquisition method is characterized by comprising the following steps:
step one, establishing an electrochemical model of a lithium ion battery pack;
applying a parameter identification working condition to the lithium ion battery pack to charge and discharge the lithium ion battery, and obtaining voltage data and current data of each single battery in the lithium ion battery pack under the charging and discharging conditions;
thirdly, calculating the discharge capacity Q corresponding to the monomer battery with the fastest discharge by adopting an ampere-hour integration method according to the electrochemical model of the lithium ion battery pack and the voltage data and the current data of each monomer battery of the lithium ion battery pack under the charging and discharging conditionsallAnd further acquiring the total electric capacity of the single batteries which are not completely discharged by a binary iterative calculation method, thereby acquiring the model parameters of each single battery of the lithium ion battery pack.
2. The method for obtaining parameters of an electrochemical model of a lithium ion battery pack according to claim 1, wherein the electrochemical model of the lithium ion battery cells established in the first step comprises an open circuit voltage Eocv(t) positive electrode active particle surface intercalation lithium concentration fraction ysurf(t) negative electrode active particle surface lithium intercalation concentration fraction xsurf(t) concentration polarization overpotential ηcon-polarization(t) reaction polarization overpotential ηact-polarization(t), ohmic polarization overpotential ηohm-polarization(t) and terminal voltage Uapp(t)。
3. The method for obtaining parameters of an electrochemical model of a lithium ion battery pack according to claim 2, wherein in the second step, voltage data and current data of the single battery under the charging and discharging conditions are obtained, and an ampere-hour integration method is adopted to calculate the discharging capacity Q corresponding to the single battery with the fastest discharging speedallObtaining a battery state of charge (SOC) sequence according to the formula (1), anda terminal voltage of the resting end is extracted,
Figure FDA0002730709760000011
fitting the unknown parameters according to equation (2):
Eocv＝Up[y0+Dy(1-soc)]-Un[x0-Dx(1-soc)] (2)
wherein SOC is the state of charge SOC of the battery, I is the external current, the discharging is specified to be positive, and the charging is specified to be negative; y is0And x0Initial rate of lithium intercalation for positive and negative electrodes, DyAnd DxThe variation range of the initial lithium intercalation rate of the anode and the cathode; positive and negative open circuit potential curve Up、UnIs a known function;
for the battery cell of which the discharge voltage does not drop to the cut-off voltage, calculating the electric quantity delta Q which can still be discharged when the whole group stops discharging by comparing the cut-off voltages of the incompletely discharged battery cell and the completely discharged battery cell, wherein the total capacity of the incompletely discharged battery cell is equal to the electric quantity delta Q which is not discharged and the electric quantity Q which is dischargedallAnd (4) adding.
4. The method for obtaining parameters of an electrochemical model of a lithium ion battery pack according to claim 3, wherein the Δ Q is calculated by a binary iteration method, and the implementation process is as follows:
(1) firstly, the voltage of the ith single battery which is not completely discharged when the discharge of the whole battery pack is cut off is obtained and is marked as UiThe discharge performance of the single battery is theoretically consistent with that of the single battery with the fastest discharge, and the slave U is intercepted from the battery data of the single battery with the fastest dischargeiThe prior discharge capacity compensation value corresponding to the cut-off voltage of 2.75V is recorded as delta Qi；
(2) Will be delta QiAnd QallAdding to obtain the total prior discharge capacity of the incompletely discharged single battery, and recording as Qall_i；
(3) Will be a prioriTotal discharge capacity Qall_iSubstituting the equation (1), obtaining SOC at different moments by using an ampere-hour integral method, and further obtaining a basic working process parameter y of the battery by using an LSF fitting method0、x0、Dy、DxCalculating the positive and negative electrode capacities Q according to the formula (3)pAnd Qn；
Figure FDA0002730709760000021
(4) Under the condition of a given current I, performing voltage simulation on the single battery by using a formula (2), intercepting the time corresponding to the voltage discharge of the battery from full charge to cut-off voltage, and then acquiring the total simulated discharge capacity Q by using an ampere-hour integration methodall_i’；
(5) Comparing the prior total discharge capacity Qall_iAnd total capacity Q of simulated dischargeall_i' if the difference between the two is greater than a given value of 0.01A · s, the mean of the two is taken and then assigned to Qall_iAssigning the optimized Qall_iSubstituting the formula (1), and repeating the steps (3) to (5) until the total prior discharge capacity Qall_iAnd total capacity Q of simulated dischargeall_i' the difference is less than a given value.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113138343A (en) * 2021-04-09 2021-07-20 阳光三星(合肥)储能电源有限公司 Capacity calibration method of battery system, battery system and readable storage medium
CN115081332A (en) * 2022-06-30 2022-09-20 上海玫克生储能科技有限公司 Working condition sensitivity analysis and data processing method and device for parameter identification
CN116595807A (en) * 2023-07-14 2023-08-15 中国第一汽车股份有限公司 Method and device for generating battery model
WO2023201781A1 (en) * 2022-04-22 2023-10-26 清华大学 State of charge update method based on power characteristic of lithium ion battery electrochemical model

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114660478B (en) * 2022-05-12 2022-09-02 中创新航科技股份有限公司 Battery device, detection method thereof, screening method and screening device for battery cells

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202130320U (en) * 2011-07-01 2012-02-01 陈永强 Intelligent vehicle-mounted storage battery energy meter
CN103688181A (en) * 2011-05-20 2014-03-26 雷诺股份公司 A method of estimating the state of charge of an electric battery
CN105866700A (en) * 2016-05-30 2016-08-17 广西大学 Lithium ion battery quick screening method
CN107576919A (en) * 2017-10-20 2018-01-12 广东石油化工学院 Power battery charged state estimating system and method based on ARMAX models
CN107656216A (en) * 2017-11-15 2018-02-02 国网辽宁省电力有限公司鞍山供电公司 A kind of lead-acid accumulator on-line monitoring is safeguarded and early warning system and performance estimating method
US20180143257A1 (en) * 2016-11-21 2018-05-24 Battelle Energy Alliance, Llc Systems and methods for estimation and prediction of battery health and performance
US20180198300A1 (en) * 2017-01-11 2018-07-12 The Chancellor Masters and Scholars of the Univers ity of Oxford Method and apparatus estimating and controlling battery state
CN108761341A (en) * 2018-06-01 2018-11-06 哈尔滨工业大学 A kind of lithium ion battery battery chemical modeling parameter acquisition methods
CN111707951A (en) * 2020-06-22 2020-09-25 北京理工大学 Battery pack consistency evaluation method and system

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103688181A (en) * 2011-05-20 2014-03-26 雷诺股份公司 A method of estimating the state of charge of an electric battery
CN202130320U (en) * 2011-07-01 2012-02-01 陈永强 Intelligent vehicle-mounted storage battery energy meter
CN105866700A (en) * 2016-05-30 2016-08-17 广西大学 Lithium ion battery quick screening method
US20180143257A1 (en) * 2016-11-21 2018-05-24 Battelle Energy Alliance, Llc Systems and methods for estimation and prediction of battery health and performance
US20180198300A1 (en) * 2017-01-11 2018-07-12 The Chancellor Masters and Scholars of the Univers ity of Oxford Method and apparatus estimating and controlling battery state
CN107576919A (en) * 2017-10-20 2018-01-12 广东石油化工学院 Power battery charged state estimating system and method based on ARMAX models
CN107656216A (en) * 2017-11-15 2018-02-02 国网辽宁省电力有限公司鞍山供电公司 A kind of lead-acid accumulator on-line monitoring is safeguarded and early warning system and performance estimating method
CN108761341A (en) * 2018-06-01 2018-11-06 哈尔滨工业大学 A kind of lithium ion battery battery chemical modeling parameter acquisition methods
CN111707951A (en) * 2020-06-22 2020-09-25 北京理工大学 Battery pack consistency evaluation method and system

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
JUNFU LI: "A parameter estimation method for a simplified electrochemical", 《ELECTROCHIMICA ACTA》 *
JUNFU LIA: "An electrochemical model for high C-rate conditions in lithium-ion batteries", 《JOURNAL OFPOWERSOURCES》 *
刘璇: "锂离子电池建模与参数识别", 《电源学报》 *
徐 兴: "车用锂离子动力电池电化学模型修正方法", 《机械工程学报》 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113138343A (en) * 2021-04-09 2021-07-20 阳光三星(合肥)储能电源有限公司 Capacity calibration method of battery system, battery system and readable storage medium
CN113138343B (en) * 2021-04-09 2023-12-26 阳光储能技术有限公司 Capacity calibration method for battery system, battery system and readable storage medium
WO2023201781A1 (en) * 2022-04-22 2023-10-26 清华大学 State of charge update method based on power characteristic of lithium ion battery electrochemical model
CN115081332A (en) * 2022-06-30 2022-09-20 上海玫克生储能科技有限公司 Working condition sensitivity analysis and data processing method and device for parameter identification
CN116595807A (en) * 2023-07-14 2023-08-15 中国第一汽车股份有限公司 Method and device for generating battery model
CN116595807B (en) * 2023-07-14 2023-10-27 中国第一汽车股份有限公司 Method and device for generating battery model

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