State of charge update method based on power characteristics of lithium-ion battery electrochemical model

Abstract

The present application proposes a method for updating the state of charge based on the power characteristics of the electrochemical model of a lithium-ion battery, including: S1: obtaining the initial state of charge and a current sequence of constant amplitude; S2: obtaining the initial state of charge information of the battery, and obtaining the battery port voltage at each moment within a preset time period according to the simulation of the lithium-ion battery electrochemical model; S3: obtaining the port power corresponding to the initial state of charge according to the battery port voltage and the current sequence amplitude; S4: adjusting the initial state of charge and the current sequence amplitude, repeating steps S1-S3, and obtaining the current amplitude-state of charge-port power surface; S5: fitting the current amplitude-state of charge-port power surface to a plane equation; S6: using the plane equation to obtain the current amplitude corresponding to the port power and the state of charge, and updating the state of charge according to the current amplitude and the preset time period. The present application can improve the computational efficiency of the electrochemical model in power application scenarios and expand the application scenarios of the electrochemical model in engineering.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion battery energy management and operation, and in particular to a method and device for updating the state of charge based on the power characteristics of a lithium-ion battery electrochemical model. Background Art

[0002] As a flexible, efficient and safe energy storage medium, lithium-ion batteries are widely used in business areas such as electricity and transportation. In the process of lithium-ion battery energy management, the battery state of charge is one of the key information that managers pay attention to. In order to obtain an accurate description of the state of charge to meet the requirements of efficient operation of lithium-ion batteries, it is necessary to use an electrochemical model to consider the time-varying port voltage characteristics of the battery. In the process of characterizing the time-varying port characteristics, it is necessary not only to ensure its accuracy, but also to consider the computational efficiency of the state of charge update in practical applications.

[0003] At present, lithium-ion battery models in engineering applications can be mainly divided into four categories: water tank model, equivalent circuit model, data-driven black box model, and electrochemical model based on chemical reaction mechanism. Among them, water tank model and equivalent circuit model are the most widely used in engineering. During the state of charge update process, the battery voltage is determined or measured by the manufacturer and regarded as a constant. For example, scholars from MIT and Argonne National Laboratory use equivalent circuit models when studying the arbitrage ability of batteries in microgrids, regard the battery voltage as a constant value, and use the port power to directly update the state of charge. For electrochemical models and black box models, the state of charge is generally obtained by state estimation methods in continuous timing simulation. For example, scholars from Beijing Institute of Technology and University of Michigan use joint state estimation methods in electrochemical models to determine the current state of charge of the battery. However, treating the battery port voltage as a constant value essentially ignores the change of the port voltage with respect to the battery state of charge during battery operation, resulting in large errors in the state of charge update process. However, using the state estimation method in continuous time series simulation to determine the state of charge requires repeated solution of the nonlinear high-order differential state equations in the electrochemical model, which requires a large amount of computing resources, has low computational efficiency, and is difficult to adapt to battery energy management operations over a longer period of time. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the first purpose of the present application is to propose a method for updating the state of charge based on the power characteristics of a lithium-ion battery electrochemical model, which solves the technical problem of the mutual exclusion of accuracy and efficiency in updating the state of charge of lithium-ion batteries in existing methods, and utilizes the high simulation accuracy of the external characteristics of the lithium-ion battery electrochemical model to consider the influence of the time-varying port voltage of the battery on the state of charge update without increasing the calculation complexity. This achieves the update of the battery state of charge without continuous timing simulation when the battery power and state of charge are known, thereby improving the calculation efficiency of the electrochemical model in power application scenarios and expanding the application scenarios of the electrochemical model in engineering.

[0006] The second objective of the present application is to provide a charge state updating device based on the power characteristics of the electrochemical model of a lithium-ion battery.

[0007] A third object of the present application is to provide a non-transitory computer-readable storage medium.

[0008] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a method for updating the state of charge based on the power characteristics of the electrochemical model of a lithium-ion battery, including: S1: obtaining the initial state of charge of the battery and a current sequence of constant amplitude; S2: obtaining the initial state information of the battery, and obtaining the battery port voltage at each moment within a preset time period based on the initial state information of the battery and the simulation of the electrochemical model of the lithium-ion battery; S3: calculating the port power corresponding to the initial state of charge based on the battery port voltage and the current sequence amplitude; S4: adjusting the initial state of charge and the current sequence amplitude, repeating steps S1-S3, respectively obtaining the port powers corresponding to multiple different initial states of charge and current sequence amplitudes, and obtaining the current amplitude-state of charge-port power surface based on the port power; S5: fitting the current amplitude-state of charge-port power surface into a plane equation; S6: based on the port power and the state of charge, using the plane equation to obtain the current amplitude corresponding to the port power and the state of charge, and updating the state of charge based on the current amplitude and the preset time period.

[0009] Optionally, in one embodiment of the present application, the initial state information of the battery includes: the surface lithium concentration of the electrode active material, the average lithium concentration of the electrode active material, the electrode electrolyte lithium concentration, and the initial value of the battery temperature.

[0010] Optionally, in one embodiment of the present application, obtaining the battery port voltage at each moment within a preset time period according to the battery initial state information and the lithium-ion battery electrochemical model simulation includes:

[0011] Obtain a battery ambient temperature sequence of constant amplitude, the battery ambient temperature sequence including the battery ambient temperature at each moment within a preset time period,

[0012] At the start of the preset time period, the parameter vector of the current moment is updated according to the lithium concentration of the electrode electrolyte, the average lithium concentration of the electrode active material and the battery temperature at the previous moment:

[0013] θ(k+1)=f θ (c e (k), c s，av (k), T b (k))

[0014] Among them, θ(k+1) is the parameter vector at the current moment, f θ is the parameter update function, c e (k) is the lithium concentration of the electrode electrolyte at the previous moment, c s,av (k) is the average lithium concentration of the electrode active material at the previous moment, T b (k) is the battery temperature at the last moment;

[0015] According to the previous moment's electrode electrolyte lithium concentration, electrode active material surface lithium concentration, battery temperature, port current and current moment parameter vector, update the current moment's reaction current intensity:

[0016] j n (k+1)=f j (c e (k), c s，surf (k), T b (k), I(k), θ(k+1))

[0017] Among them, j n (k+1) is the current intensity of the reaction, f j is the reaction current update function, c e (k) is the lithium concentration of the electrode electrolyte at the previous moment, c s,surf (k) is the lithium concentration on the surface of the electrode active material at the previous moment, T b (k) is the battery temperature at the previous moment, I(k) is the port current at the previous moment, and θ(k+1) is the parameter vector at the current moment;

[0018] According to the current reaction current intensity and parameter vector, update the current electrode surface potential difference:

[0019] φ se (k+1)=f φ (j n (k+1),θ(k+1))

[0020] Among them, φ se (k+1) is the electrode surface potential difference at the current moment, f φ is the electrode surface potential difference update function, j n(k+1) is the reaction current intensity at the current moment, θ(k+1) is the parameter vector at the current moment;

[0021] Update the lithium concentration of the electrode active material at the current moment according to the average lithium concentration of the electrode active material at the previous moment, the lithium concentration on the surface of the electrode active material, the reaction current intensity at the current moment, the parameter vector at the current moment and the sampling interval:

[0022] c s，av (k+1)=f av (c s，av (k), c s，surf (k), j n (k+1), θ(k+1), Δt)

[0023] c s，surf (k+1)=f surf (c s，av (k), c s，surf (k), j n (k+1), θ(k+1), Δt)

[0024] Among them, c s，av (k+1) is the average lithium concentration of the electrode active material at the current moment, f av is the average lithium concentration update function of the electrode active material, c s，av (k) is the average lithium concentration of the electrode active material at the previous moment, c s，surf (k) is the lithium concentration on the surface of the electrode active material at the previous moment, j n (k+1) is the reaction current intensity at the current moment, θ(k+1) is the parameter vector at the current moment, Δt is the sampling interval, c s，surf (k+1) is the lithium concentration on the surface of the electrode active material at the current moment, f surf is the lithium concentration update function on the surface of the electrode active material, c s，av (k) is the average lithium concentration of the electrode active material at the previous moment, c s，surf (k) is the lithium concentration on the surface of the electrode active material at the previous moment, j n (k+1) is the reaction current intensity at the current moment, θ(k+1) is the parameter vector at the current moment, and Δt is the sampling interval;

[0025] Update the current electrode electrolyte lithium concentration based on the previous moment's electrode electrolyte lithium concentration, port current, current moment parameter vector and sampling interval:

[0026] c e (k+1)=f e (c e (k), I(k), θ(k+1), Δt)

[0027] Among them, ce (k+1) is the lithium concentration of the electrode electrolyte at the current moment, f e is the electrode electrolyte lithium concentration update function, c e (k) is the lithium concentration of the electrode electrolyte at the previous moment, I(k) is the port current at the previous moment, θ(k+1) is the parameter vector at the current moment, and Δt is the sampling interval;

[0028] According to the current electrode electrolyte lithium concentration, electrode active material surface lithium concentration, reaction current intensity, parameter vector and the battery temperature and port current at the previous moment, the current battery port voltage V and the battery internal potential difference U are obtained:

[0029] V(k+1)=f V (c e (k+1), c s，surf (k+1), j n (k+1), T b (k), I(k), θ(k+1))

[0030] U(k+1)=f U (c e (k+1), c s，surf (k+1), j n (k+1), T b (k), I(k), θ(k+1))

[0031] Among them, V(k+1) is the battery terminal voltage at the current moment, f V is the battery port voltage update function, c e (k+1) is the lithium concentration of the electrode electrolyte at the current moment, c s，surf (k+1) is the lithium concentration on the surface of the electrode active material at the current moment, j n (k+1) is the current intensity of the reaction, T b (k) is the battery temperature at the previous moment, I(k) is the port current at the previous moment, θ(k+1) is the parameter vector at the current moment, U(k+1) is the potential difference in the battery at the current moment, and f U is the potential difference update function in the battery, c e (k+1) is the lithium concentration of the electrode electrolyte at the current moment, c s,surf (k+1) is the lithium concentration on the surface of the electrode active material at the current moment, j n (k+1) is the current intensity of the reaction, T b (k) is the battery temperature at the previous moment, I(k) is the port current at the previous moment, and θ(k+1) is the parameter vector at the current moment;

[0032] According to the battery port voltage, the potential difference in the battery, the reaction current intensity, the parameter vector and the battery temperature, the ambient temperature, the port current and the sampling interval at the previous moment, the battery temperature at the current moment is obtained:

[0033] T b (k+1)=f T (V(k+1),U(k+1),j n (k+1),T b (k),T amb (k),I(k),θ(k+1),Δt)

[0034] Among them, T b (k+1) is the battery temperature at the current moment, f T is the battery temperature update function, V(k+1) is the battery terminal voltage at the current moment, U(k+1) is the potential difference in the battery at the current moment, j n (k+1) is the current intensity of the reaction, T b (k) is the battery temperature at the last moment, T amb (k) is the ambient temperature at the previous moment, I(k) is the port current at the previous moment, θ(k+1) is the parameter vector at the current moment, and Δt is the sampling interval;

[0035] Repeat the above simulation iteration update steps, and cyclically update the current state value from the previous state value: parameter vector, reaction current intensity, electrode surface potential difference, electrode active material lithium concentration, electrode electrolyte lithium concentration, and output the battery port voltage and battery temperature according to the state update result until the preset time period ends, so as to obtain the battery port voltage at each moment within the preset time period.

[0036] Among them, the battery port voltage at each moment in the preset time period can be expressed as

[0037] V=[V1 V2 … V k … V N ]

[0038] Where V is the battery port voltage at each moment within the preset time period, V k is the voltage value of the battery port at the kth moment, V N is the battery port voltage value at the Nth moment.

[0039] Optionally, in one embodiment of the present application, the port power corresponding to the initial state of charge is calculated according to the battery port voltage and current sequence amplitude, including:

[0040] The average port voltage within a preset time period is obtained according to the battery port voltage, and the port power corresponding to the initial state of charge and the current sequence amplitude is calculated according to the average port voltage and the current sequence amplitude.

[0041] Among them, the average port voltage is expressed as:

[0042]

[0043] in, is the average port voltage, V k is the voltage value of the battery port at the kth moment, V N is the battery port voltage value at the Nth moment, N is the total number of moments in the preset time period,

[0044] The port power is expressed as:

[0045]

[0046] Where P is the port power, SOC0 is the initial state of charge, T amb is the set battery ambient temperature value, I is the current sequence amplitude, is the average port voltage.

[0047] Optionally, in one embodiment of the present application, the initial state of charge and the current sequence amplitude are adjusted, and steps S1-S3 are repeated to obtain port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, respectively, and a current amplitude-state of charge-port power surface is obtained according to the port power, including:

[0048] While keeping the battery ambient temperature constant, adjust the initial state of charge and current sequence amplitude of the battery, repeat S1-S3, obtain the port power corresponding to multiple different initial states of charge and current sequence amplitudes, connect the port power smoothly, and obtain the current amplitude-state of charge-port power surface.

[0049] Among them, the current amplitude-charge state-port power surface is expressed as:

[0050]

[0051] Among them, f P T = T amb The current amplitude-state of charge-port power surface function at the time of SOC0 is the initial state of charge, P is the port power, I is the current sequence amplitude, T amb is the set battery ambient temperature value, and T is the actual battery ambient temperature.

[0052] Optionally, in one embodiment of the present application, the current amplitude-state of charge-port power surface is fitted into a plane equation, which is expressed as:

[0053]

[0054] Among them, f P T = T amb The current amplitude-state of charge-port power surface function at the time of SOC0 is the initial state of charge, P is the port power, I is the current sequence amplitude, T amb is the set battery ambient temperature value, T is the actual battery ambient temperature. A, B, C are the plane fitting coefficients, and D is the plane fitting constant coefficient.

[0055] Optionally, in one embodiment of the present application, according to the port power and the state of charge, the current amplitude corresponding to the port power and the state of charge is obtained by using a plane equation, and the state of charge is updated according to the current amplitude and a preset time period, including:

[0056] Under the condition of keeping the battery ambient temperature constant, according to the known port power and state of charge, the current amplitude is obtained by using the plane equation.

[0057] Among them, the current amplitude is expressed as:

[0058]

[0059] Where I is the current amplitude, f I is the current amplitude function, SOC0 is the initial state of charge, T amb is the set ambient temperature value, T is the actual ambient temperature of the battery, a0 is the constant coefficient of the current amplitude function, a1 is the first-order coefficient corresponding to SOC0 in the current amplitude function, a2 is the first-order coefficient corresponding to P in the current amplitude function, P is the port power,

[0060] a0, a1, a2 can be derived from the plane fitting coefficients A, B, C, D:

[0061]

[0062]

[0063]

[0064] Among them, A, B, C are the plane fitting coefficients, D is the plane fitting constant coefficient, a0 is the constant coefficient of the current amplitude function, a1 is the first-order coefficient corresponding to SOC0 in the current amplitude function, and a2 is the first-order coefficient corresponding to P in the current amplitude function;

[0065] The state of charge is updated according to the current amplitude and the preset time period, which is expressed as:

[0066]

[0067] ΔT=NΔt

[0068] SOC T+1 =SOC T +ΔSOC

[0069] Where ΔSOC is the change in state of charge in adjacent time periods, I is the current amplitude, C0 is the total battery capacity in ampere-hours, ΔT is the length of the preset time period, N is the total number of moments in the preset time period, is the sampling interval, and SOC T+1 The battery state of charge at the beginning of the next time period, SOC T The battery state of charge at the beginning of this time period.

[0070] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a charge state updating device based on the power characteristics of the lithium-ion battery electrochemical model, comprising:

[0071] An acquisition module, used for acquiring an initial state of charge of the battery and a current sequence of a constant amplitude;

[0072] The processing module is used to obtain the initial state information of the battery, and obtain the battery port voltage at each moment within a preset time period according to the initial state information of the battery and the electrochemical model simulation of the lithium-ion battery;

[0073] A calculation module, used to calculate the port power corresponding to the initial state of charge according to the battery port voltage and current sequence amplitude;

[0074] A circulation module is used to adjust the initial state of charge and the current sequence amplitude, repeatedly call the acquisition module, the processing module and the calculation module, respectively obtain the port powers corresponding to multiple different initial states of charge and current sequence amplitudes, and obtain the current amplitude-state of charge-port power surface according to the port power;

[0075] A fitting module, used for fitting the current amplitude-charge state-port power surface into a plane equation;

[0076] The update module is used to obtain the current amplitude corresponding to the port power and the state of charge by using the plane equation according to the port power and the state of charge, and update the state of charge according to the current amplitude and a preset time period.

[0077] In order to achieve the above-mentioned objectives, the third aspect embodiment of the present application proposes a non-temporary computer-readable storage medium, which, when the instructions in the storage medium are executed by a processor, can execute a charge state update method based on the power characteristics of the lithium-ion battery electrochemical model.

[0078] The state of charge update method based on the power characteristics of the lithium-ion battery electrochemical model, the state of charge update device based on the power characteristics of the lithium-ion battery electrochemical model, and the non-temporary computer storable medium of the embodiments of the present application solve the technical problem of the mutual exclusion of accuracy and efficiency of the lithium-ion battery state of charge update in the existing method, and utilize the high simulation accuracy of the external characteristics of the lithium-ion battery electrochemical model to consider the influence of the time-varying port voltage of the battery on the state of charge update without increasing the calculation complexity, so that when the battery power and state of charge are known, the battery state of charge can be updated without continuous timing simulation, thereby improving the calculation efficiency of the electrochemical model in power application scenarios and expanding the application scenarios of the electrochemical model in engineering.

[0079] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0081] Figure 1 A flow chart of a method for updating the state of charge based on the power characteristics of the electrochemical model of a lithium-ion battery provided in Example 1 of the present application;

[0082] Figure 2 A schematic diagram of the structure of a lithium-ion battery cell according to a method for updating the state of charge based on the power characteristics of a lithium-ion battery electrochemical model according to an embodiment of the present application;

[0083] Figure 3 Another flow chart of the method for updating the state of charge based on the power characteristics of the electrochemical model of a lithium-ion battery according to an embodiment of the present application;

[0084] Figure 4 A schematic diagram of the structure of a charge state updating device based on the power characteristics of the electrochemical model of a lithium-ion battery provided in Example 2 of the present application. DETAILED DESCRIPTION

[0085] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0086] In existing research on lithium-ion battery energy operation management, (1) if the port voltage is regarded as a constant value and the state of charge is determined directly using the port power, it is difficult to ensure the accuracy of the state of charge update; (2) if the state estimation is performed in a continuous timing simulation, the calculation efficiency is low and a large amount of computing resources are required for long-term management. In view of the above problems, an efficient state of charge update method that can reflect the true power characteristics of the battery operation remains to be studied. Therefore, the state of charge update method for the power characteristics of the lithium-ion battery electrochemical model needs to accurately consider the time-varying characteristics of the battery port voltage and meet the computational efficiency in long-term battery energy operation management.

[0087] The present application proposes a method for updating the state of charge based on the power characteristics of the electrochemical model of a lithium-ion battery. The method utilizes the high simulation accuracy of the external characteristics of the electrochemical model of the lithium-ion battery, and considers the influence of the time-varying port voltage of the battery on the update of the state of charge without increasing the calculation complexity. When the battery power and state of charge are known, the battery state of charge can be updated without continuous timing simulation, which improves the calculation efficiency of the electrochemical model in power application scenarios and expands the application scenarios of the electrochemical model in engineering.

[0088] The relevant technologies of this application include: Lithium-ion battery electrochemical model construction and simulation technology: The lithium-ion electrochemical model is composed of a set of nonlinear high-order differential state equations, which provide relatively accurate internal state information and external characteristic information by accurately describing the internal chemical reactions of the battery. Multivariate equation fitting technology: Multivariate equation fitting is to connect a series of sample points in three-dimensional or high-dimensional space using a smooth surface so that the surface can approximate the distribution of sample points. In this application, plane fitting in three-dimensional space is used, which involves sample point fitting of three variables, thereby giving the required fitting coefficients.

[0089] The following describes a method and device for updating the state of charge based on the power characteristics of a lithium-ion battery electrochemical model according to an embodiment of the present application with reference to the accompanying drawings.

[0090] Figure 1 This is a flow chart of a method for updating the state of charge based on the power characteristics of the electrochemical model of a lithium-ion battery provided in Example 1 of the present application.

[0091] like Figure 1 As shown, the charge state updating method based on the power characteristics of the lithium-ion battery electrochemical model includes the following steps:

[0092] S1: Obtain the initial state of charge of the battery and a current sequence of constant amplitude;

[0093] S2: Obtaining the initial state information of the battery, and obtaining the battery port voltage at each moment within a preset time period according to the initial state information of the battery and the electrochemical model simulation of the lithium-ion battery;

[0094] S3: Calculate the port power corresponding to the initial state of charge according to the battery port voltage and current sequence amplitude;

[0095] S4: adjusting the initial state of charge and the current sequence amplitude, repeating steps S1-S3, respectively obtaining the port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, and obtaining a current amplitude-state of charge-port power surface according to the port power;

[0096] S5: Fitting the current amplitude-state of charge-port power surface into a plane equation;

[0097] S6: According to the port power and the state of charge, the plane equation is used to obtain the current amplitude corresponding to the port power and the state of charge, and the state of charge is updated according to the current amplitude and a preset time period.

[0098] The state of charge updating method based on the power characteristics of the electrochemical model of a lithium-ion battery in the embodiment of the present application includes: S1: obtaining the initial state of charge of the battery and a current sequence of constant amplitude; S2: obtaining the initial state information of the battery, and obtaining the battery port voltage at each moment within a preset time period according to the initial state information of the battery and the electrochemical model simulation of the lithium-ion battery; S3: calculating the port power corresponding to the initial state of charge according to the battery port voltage and the current sequence amplitude; S4: adjusting the initial state of charge and the current sequence amplitude, repeating steps S1-S3, respectively obtaining the port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, and obtaining a current amplitude-state of charge-port power surface according to the port power; S5: fitting the current amplitude-state of charge-port power surface into a plane equation; S6: according to the port power and the state of charge, obtaining the current amplitude corresponding to the port power and the state of charge using the plane equation, and updating the state of charge according to the current amplitude and the preset time period. As a result, the technical problem of the mutually exclusive accuracy and efficiency of updating the state of charge of lithium-ion batteries in the existing methods can be solved. The high accuracy of the simulation of the external characteristics of the electrochemical model of the lithium-ion battery is utilized, and the influence of the time-varying port voltage of the battery on the update of the state of charge is considered without increasing the calculation complexity. When the battery power and state of charge are known, the update of the battery state of charge is completed without continuous timing simulation, which improves the calculation efficiency of the electrochemical model in power application scenarios and expands the application scenarios of the electrochemical model in engineering.

[0099] This application proposes a method for updating the state of charge based on the power characteristics of the electrochemical model of lithium-ion batteries. The electrochemical model is used to describe the time-varying characteristics of the lithium-ion battery port voltage as the state of charge changes. At the same time, a power-current characteristic description method is adopted to construct a current amplitude-state of charge-port power surface and perform plane fitting. While improving the accuracy of state update, long-term continuous time series simulation of the electrochemical model in battery energy management is avoided. This method is used to test the battery in a short period of time, and the power-current characteristics are described using a fitting plane based on the electrochemical model. In a long period of time, the above characteristic plane equation is used to perform relevant calculations for battery energy operation management.

[0100] While retaining the time-varying characteristics of the port voltage during the operation of the lithium-ion battery, the present application does not increase the computational complexity of the battery energy operation management. The present application can apply the electrochemical model of the lithium-ion battery to long-term optimization scenarios such as day-ahead planning and joint scheduling without the need for continuous timing simulation of the electrochemical model with high computational complexity. It provides charge state update information that takes into account both accuracy and efficiency for the battery energy operation management, supports the efficient and economic operation of lithium-ion batteries in different scenarios, and has important practical significance and good application prospects.

[0101] Set the battery ambient temperature, denoted as T amb ,In this application, the battery ambient temperature remains constant.

[0102] The initial state of charge of the battery is obtained, denoted as SOC0, where the domain of the initial state of charge is [0,1].

[0103] To obtain a current sequence with a constant amplitude, it can be written as:

[0104]

[0105] Where I is the current sequence amplitude, N is the total number of moments in the preset time period, and the current action period at each moment is t k ≤t <t k+1 , the sampling interval is Δt = t k+1 -t k .

[0106] Furthermore, in the embodiment of the present application, the initial state information of the battery includes: the surface lithium concentration of the electrode active material, the average lithium concentration of the electrode active material, the lithium concentration of the electrode electrolyte, and the initial value of the battery temperature.

[0107] Obtaining the initial state information of the battery, including: obtaining the type of electrode active material used for the electrode to be analyzed, querying the average lithium concentration of the electrode active material corresponding to the maximum and minimum charge states of the electrode active material, obtaining the initial value of the average lithium concentration of the electrode active material according to the proportional relationship between the charge state and the average lithium concentration, assuming that the initial distribution of the lithium concentration of the electrode active material is uniform under the initial state, obtaining the surface lithium concentration of the electrode active material equal to the initial value of the average lithium concentration, obtaining the initial value of the electrode electrolyte lithium concentration according to the parameter setting, and setting the initial value of the battery temperature to the ambient temperature;

[0108] The average lithium concentration of the electrode active material is:

[0109]

[0110] The lithium concentration on the surface of the electrode active material is:

[0111]

[0112] The lithium concentration of the electrode electrolyte is:

[0113] c e (0) = f init，e (c e0 )

[0114] The initial value of battery temperature is:

[0115] T b (0) = T amb

[0116] in, is the initial average lithium concentration of the positive and negative electrode active materials, f init , is the initial value setting function of the average lithium concentration of the electrode active material, It is the theoretical minimum value of the average lithium concentration of the active materials in the positive and negative electrodes of the battery. It is the theoretical maximum value of the average lithium concentration of the active materials in the positive and negative electrodes of the battery, SOC0 is the initial state of charge, is the initial lithium concentration on the surface of the positive and negative electrode active materials, c e (0) is the initial value of the lithium concentration of the electrode electrolyte, f init , is the initial value setting function of the electrode electrolyte lithium concentration, c e0 is the electrode electrolyte lithium concentration material parameter, T b (0) is the initial value of battery temperature, T amb is the battery ambient temperature.

[0117] Further, in the embodiment of the present application, the battery port voltage at each moment in a preset time period is obtained according to the battery initial state information and the electrochemical model simulation of the lithium-ion battery, including:

[0118] A battery environment temperature sequence with a constant amplitude is obtained, where the battery environment temperature sequence includes the battery environment temperature at each moment within a preset time period, wherein the environment temperature sequence can be recorded as:

[0119]

[0120] Among them, T amb is the battery environment temperature, N is the total number of moments in the preset time period, and the battery environment temperature action period at each moment is t k ≤t <t k+1 , the sampling interval is Δt = t k+1 -t k .

[0121] At the start of the preset time period, the parameter vector of the current moment is updated according to the lithium concentration of the electrode electrolyte, the average lithium concentration of the electrode active material and the battery temperature at the previous moment:

[0122] θ(k+1)=f θ (c e (k), c s，av (k), T b (k))

[0123] Among them, θ(k+1) is the parameter vector at the current moment, f θ is the parameter update function, c e (k) is the lithium concentration of the electrode electrolyte at the previous moment, c s,av (k) is the average lithium concentration of the electrode active material at the previous moment, T b (k) is the battery temperature at the last moment;

[0124] According to the previous moment's electrode electrolyte lithium concentration, electrode active material surface lithium concentration, battery temperature, port current and current moment parameter vector, update the current moment's reaction current intensity:

[0125] j n (k+1)=f j (c e (k), c s，surf (k), T b (k), I(k), θ(k+1))

[0126] Among them, j n (k+1) is the current intensity of the reaction, f j is the reaction current update function, c e (k) is the lithium concentration of the electrode electrolyte at the previous moment, c s,surf (k) is the lithium concentration on the surface of the electrode active material at the previous moment, T b(k) is the battery temperature at the previous moment, I(k) is the port current at the previous moment, and θ(k+1) is the parameter vector at the current moment;

[0127] According to the current reaction current intensity and parameter vector, update the current electrode surface potential difference:

[0128] φ se (k+1)=f φ (j n (k+1),θ(k+1))

[0129] Among them, φ se (k+1) is the electrode surface potential difference at the current moment, f φ is the electrode surface potential difference update function, j n (k+1) is the reaction current intensity at the current moment, θ(k+1) is the parameter vector at the current moment;

[0130] Update the lithium concentration of the electrode active material at the current moment according to the average lithium concentration of the electrode active material at the previous moment, the lithium concentration on the surface of the electrode active material, the reaction current intensity at the current moment, the parameter vector at the current moment and the sampling interval:

[0131] c s，av (k+1)=f av (c s，av (k), c s，surf (k), j n (k+1), θ(k+1), Δt)

[0132] c s，surf (k+1)=f surf (c s，av (k), c s，surf (k), j n (k+1), θ(k+1), Δt)

[0133] Among them, c s，av (k+1) is the average lithium concentration of the electrode active material at the current moment, f av is the average lithium concentration update function of the electrode active material, c s，av (k) is the average lithium concentration of the electrode active material at the previous moment, c s，surf (k) is the lithium concentration on the surface of the electrode active material at the previous moment, j n (k+1) is the reaction current intensity at the current moment, θ(k+1) is the parameter vector at the current moment, Δt is the sampling interval, c s，surf (k+1) is the lithium concentration on the surface of the electrode active material at the current moment, f surf is the lithium concentration update function on the surface of the electrode active material, c s，av (k) is the average lithium concentration of the electrode active material at the previous moment, cs，surf (k) is the lithium concentration on the surface of the electrode active material at the previous moment, j n (k+1) is the reaction current intensity at the current moment, θ(k+1) is the parameter vector at the current moment, and Δt is the sampling interval;

[0134] Update the current electrode electrolyte lithium concentration based on the previous moment's electrode electrolyte lithium concentration, port current, current moment parameter vector and sampling interval:

[0135] c e (k+1)=f e (c e (k), I(k), θ(k+1), Δt)

[0136] Among them, c e (k+1) is the lithium concentration of the electrode electrolyte at the current moment, f e is the electrode electrolyte lithium concentration update function, c e (k) is the lithium concentration of the electrode electrolyte at the previous moment, I(k) is the port current at the previous moment, θ(k+1) is the parameter vector at the current moment, and Δt is the sampling interval;

[0137] According to the current electrode electrolyte lithium concentration, electrode active material surface lithium concentration, reaction current intensity, parameter vector and the battery temperature and port current at the previous moment, the current battery port voltage V and the battery internal potential difference U are obtained:

[0138] V(k+1)=f V (c e (k+1), c s，surf (k+1), j n (k+1), T b (k), I(k), θ(k+1))

[0139] U(k+1)=f U (c e (k+1), c s，surf (k+1), j n (k+1), T b (k), I(k), θ(k+1))

[0140] Among them, V(k+1) is the battery terminal voltage at the current moment, f V is the battery port voltage update function, c e (k+1) is the lithium concentration of the electrode electrolyte at the current moment, c s，surf (k+1) is the lithium concentration on the surface of the electrode active material at the current moment, j n (k+1) is the current intensity of the reaction, T b(k) is the battery temperature at the previous moment, I(k) is the port current at the previous moment, θ(k+1) is the parameter vector at the current moment, U(k+1) is the potential difference in the battery at the current moment, and f U is the potential difference update function in the battery, c e (k+1) is the lithium concentration of the electrode electrolyte at the current moment, c s，surf (k+1) is the lithium concentration on the surface of the electrode active material at the current moment, j n (k+1) is the current intensity of the reaction, T b (k) is the battery temperature at the previous moment, I(k) is the port current at the previous moment, and θ(k+1) is the parameter vector at the current moment;

[0141] According to the battery port voltage, the potential difference in the battery, the reaction current intensity, the parameter vector and the battery temperature, the ambient temperature, the port current and the sampling interval at the previous moment, the battery temperature at the current moment is obtained:

[0142] T b (k+1)=f T (V(k+1),U(k+1),j n (k+1), T b (k), T amb (k), I(k), θ(k+1), Δt)

[0143] Among them, T b (k+1) is the battery temperature at the current moment, f T is the battery temperature update function, V(k+1) is the battery terminal voltage at the current moment, U(k+1) is the potential difference in the battery at the current moment, j n (k+1) is the current intensity of the reaction, T b (k) is the battery temperature at the last moment, T amb (k) is the ambient temperature at the previous moment, I(k) is the port current at the previous moment, θ(k+1) is the parameter vector at the current moment, and Δt is the sampling interval;

[0144] Repeat the above simulation iteration update steps, and cyclically update the current state value from the previous state value: parameter vector, reaction current intensity, electrode surface potential difference, electrode active material lithium concentration, electrode electrolyte lithium concentration, and output the battery port voltage and battery temperature according to the state update result until the preset time period ends, so as to obtain the battery port voltage at each moment within the preset time period.

[0145] Among them, the battery port voltage at each moment in the preset time period can be expressed as

[0146] V=[V1 V2 … V k … V N ]

[0147] Where V is the battery port voltage at each moment within the preset time period, V k is the voltage value of the battery port at the kth moment, V N is the battery port voltage value at the Nth moment,

[0148] The above simulation iterative update can be recorded as:

[0149] V=f bat (SOC0, T amb , I)

[0150] Where V is the battery port voltage at each moment within the preset time period, f bat is a set of state update functions, SOC0 is the initial state of charge, T amb is the battery ambient temperature, and I is the current sequence amplitude.

[0151] In this application, the parameters such as reaction current intensity, electrode surface potential difference, electrode electrolyte lithium concentration, electrode active material surface lithium concentration, and electrode active material average lithium concentration are all vectors, and there are 8 sampling points in space at each moment. The specific examples are as follows:

[0152] The reaction current intensity, electrode surface potential difference, electrode electrolyte lithium concentration, electrode active material surface lithium concentration, and electrode active material average lithium concentration are measured at four sampling points along the electrode thickness direction at the positive and negative electrodes of the battery, respectively. Figure 2 As shown, it is written as:

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] Among them, j n (k) is the current intensity of the reaction current at the current moment, is the reaction current intensity at sampling point 1 at the current moment, is the reaction current intensity at sampling point 4 at the current moment, φ se (k) is the electrode surface potential difference at the current moment, is the electrode surface potential difference at sampling point 1 at the current moment, is the electrode surface potential difference at sampling point 4 at the current moment, c e (k) is the lithium concentration of the electrode electrolyte at the current moment, is the electrode electrolyte lithium concentration at the current coordinate sampling point 1, is the electrode electrolyte lithium concentration at the current coordinate sampling point 4, c s,av (k) is the average lithium concentration of the electrode active material at the current moment, is the average lithium concentration of the electrode active material at the sampling point 1 at the current time, is the average lithium concentration of the electrode active material at the sampling point 4 at the current time, c s,surf (k) is the lithium concentration on the surface of the electrode active material at the current moment, is the lithium concentration on the surface of the electrode active material at the sampling point 1 at the current time, is the lithium concentration on the surface of the electrode active material at the sampling point 4 at the current moment.

[0159] Further, in the embodiment of the present application, the port power corresponding to the initial state of charge is calculated based on the battery port voltage and current sequence amplitude, including:

[0160] The average port voltage within a preset time period is obtained according to the battery port voltage, and the port power corresponding to the initial state of charge and the current sequence amplitude is calculated according to the average port voltage and the current sequence amplitude.

[0161] Among them, the average port voltage is expressed as:

[0162]

[0163] in, is the average port voltage, V k is the voltage value of the battery port at the kth moment, V N is the battery port voltage value at the Nth moment, N is the total number of moments in the preset time period,

[0164] The port power is expressed as:

[0165]

[0166] Where P is the port power, SOC0 is the initial state of charge, T amb is the set battery ambient temperature value, I is the current sequence amplitude, is the average port voltage.

[0167] Further, in the embodiment of the present application, the initial state of charge and the current sequence amplitude are adjusted, and steps S1-S3 are repeated to obtain the port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, respectively, and according to the port power, a current amplitude-state of charge-port power surface is obtained, including:

[0168] While keeping the battery ambient temperature constant, adjust the initial state of charge and current sequence amplitude of the battery, repeat S1-S3, obtain the port power corresponding to multiple different initial states of charge and current sequence amplitudes, connect the port power smoothly, and obtain the current amplitude-state of charge-port power surface.

[0169] Among them, the current amplitude-charge state-port power surface is expressed as:

[0170]

[0171] Among them, f P T = T amb The current amplitude-state of charge-port power surface function at the time of SOC0 is the initial state of charge, P is the port power, I is the current sequence amplitude, T amb is the set battery ambient temperature value, and T is the actual battery ambient temperature.

[0172] Further, in the embodiment of the present application, the current amplitude-state of charge-port power surface is fitted into a plane equation, which is expressed as:

[0173]

[0174] Among them, f P T = T amb The current amplitude-state of charge-port power surface function at the time of SOC0 is the initial state of charge, P is the port power, I is the current sequence amplitude, T amb is the set battery ambient temperature value, T is the actual battery ambient temperature. A, B, C are the plane fitting coefficients, and D is the plane fitting constant coefficient.

[0175] Further, in the embodiment of the present application, according to the port power and the state of charge, the current amplitude corresponding to the port power and the state of charge is obtained by using a plane equation, and the state of charge is updated according to the current amplitude and a preset time period, including:

[0176] Under the condition of keeping the battery ambient temperature constant, according to the known port power and state of charge, the current amplitude is obtained by using the plane equation.

[0177] Among them, the current amplitude is expressed as:

[0178]

[0179] Where I is the current amplitude, f I is the current amplitude function, SOC0 is the initial state of charge, T ambis the set ambient temperature value, T is the actual ambient temperature of the battery, a0 is the constant coefficient of the current amplitude function, a1 is the first-order coefficient corresponding to SOC0 in the current amplitude function, a2 is the first-order coefficient corresponding to P in the current amplitude function, P is the port power,

[0180] a0, a1, a2 can be derived from the plane fitting coefficients A, B, C, D:

[0181]

[0182]

[0183]

[0184] Among them, A, B, C are the plane fitting coefficients, D is the plane fitting constant coefficient, a0 is the constant coefficient of the current amplitude function, a1 is the first-order coefficient corresponding to SOC0 in the current amplitude function, and a2 is the first-order coefficient corresponding to P in the current amplitude function;

[0185] The state of charge is updated according to the current amplitude and the preset time period, which is expressed as:

[0186]

[0187] ΔT=NΔt

[0188] SOC T+1 =SOC T +ΔsOC

[0189] Where ΔSOC is the change in state of charge in adjacent time periods, I is the current amplitude, C0 is the total battery capacity in ampere-hours, ΔT is the length of the preset time period, N is the total number of moments in the preset time period, Δt is the sampling interval, and SOC T+1 The battery state of charge at the beginning of the next time period, SOC T The battery state of charge at the beginning of this time period.

[0190] Figure 3 This is another flow chart of a method for updating the state of charge based on the power characteristics of a lithium-ion battery electrochemical model according to an embodiment of the present application.

[0191] like Figure 3As shown, the battery ambient temperature and initial state of charge are preset to obtain a constant amplitude current sequence. Perform electrochemical model simulation according to the preset parameters and the constant amplitude current sequence, update the parameter vector, reaction current intensity, electrode surface potential difference, electrode active material lithium concentration, electrode electrolyte lithium concentration, and calculate the battery port voltage and temperature. Calculate the port average power under the current state of charge and current amplitude based on the calculated port voltage average value and current sequence amplitude. Adjust the initial state of charge and current sequence amplitude, repeat the above steps, form a current amplitude-state of charge-port power surface, and use the plane equation to fit the above surface in engineering. When the state of charge is updated, the current sequence amplitude can be derived from the above plane equation based on the known battery port power and initial state of charge, and the state of charge can be updated using the obtained amplitude.

[0192] Figure 4 A schematic diagram of the structure of a charge state updating device based on the power characteristics of the electrochemical model of a lithium-ion battery provided in Example 2 of the present application.

[0193] like Figure 4 As shown, the charge state updating device based on the power characteristics of the lithium-ion battery electrochemical model includes:

[0194] An acquisition module 10 is used to acquire an initial state of charge of the battery and a current sequence of a constant amplitude;

[0195] The processing module 20 is used to obtain the initial state information of the battery, and obtain the battery port voltage at each moment within a preset time period according to the initial state information of the battery and the electrochemical model simulation of the lithium-ion battery;

[0196] A calculation module 30, used to calculate the port power corresponding to the initial state of charge according to the battery port voltage and current sequence amplitude;

[0197] The circulation module 40 is used to adjust the initial state of charge and the current sequence amplitude, repeatedly call the acquisition module, the processing module and the calculation module, respectively obtain the port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, and obtain the current amplitude-state of charge-port power surface according to the port power;

[0198] A fitting module 50, used for fitting the current amplitude-state of charge-port power surface into a plane equation;

[0199] The updating module 60 is used to obtain the current amplitude corresponding to the port power and the state of charge by using the plane equation according to the port power and the state of charge, and update the state of charge according to the current amplitude and a preset time period.

[0200] The state of charge updating device based on the power characteristics of the lithium-ion battery electrochemical model of the embodiment of the present application includes an acquisition module, which is used to acquire the initial state of charge of the battery and a current sequence of constant amplitude; a processing module, which is used to acquire the initial state of charge information of the battery, and obtain the battery port voltage at each moment within a preset time period according to the initial state of the battery and the electrochemical model simulation of the lithium-ion battery; a calculation module, which is used to calculate the port power corresponding to the initial state of charge according to the battery port voltage and the current sequence amplitude; a circulation module, which is used to adjust the initial state of charge and the current sequence amplitude, repeatedly call the acquisition module, the processing module and the calculation module, respectively obtain the port power corresponding to multiple different initial states of charge and current sequence amplitudes, and obtain the current amplitude-state of charge-port power surface according to the port power; a fitting module, which is used to fit the current amplitude-state of charge-port power surface into a plane equation; an update module, which is used to obtain the current amplitude corresponding to the port power and the state of charge using the plane equation according to the port power and the state of charge, and update the state of charge according to the current amplitude and the preset time period. As a result, the technical problem of the mutually exclusive accuracy and efficiency of updating the state of charge of lithium-ion batteries in the existing methods can be solved. The high accuracy of the simulation of the external characteristics of the electrochemical model of the lithium-ion battery is utilized, and the influence of the time-varying port voltage of the battery on the update of the state of charge is considered without increasing the calculation complexity. When the battery power and state of charge are known, the update of the battery state of charge is completed without continuous timing simulation, which improves the calculation efficiency of the electrochemical model in power application scenarios and expands the application scenarios of the electrochemical model in engineering.

[0201] In order to implement the above-mentioned embodiments, the present application also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the charge state update method based on the power characteristics of the lithium-ion battery electrochemical model of the above-mentioned embodiment is implemented.

[0202] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0203] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0204] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0205] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0206] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0207] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0208] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0209] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for updating the state of charge based on the power characteristics of a lithium-ion battery electrochemical model, characterized in that: The following steps are involved: S1: Obtain the initial state of charge of the battery and a current sequence of constant amplitude; S2: Obtaining the initial state information of the battery, and obtaining the battery port voltage at each moment within a preset time period according to the initial state information of the battery and the electrochemical model simulation of the lithium-ion battery, wherein the initial state information of the battery includes: the surface lithium concentration of the electrode active material, the average lithium concentration of the electrode active material, the lithium concentration of the electrode electrolyte, and the initial value of the battery temperature; S3: Calculating the port power corresponding to the initial state of charge according to the battery port voltage and current sequence amplitude; S4: adjusting the initial state of charge and the current sequence amplitude, repeating steps S1-S3, respectively obtaining port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, and obtaining a current amplitude-state of charge-port power surface according to the port power; S5: fitting the current amplitude-state of charge-port power surface into a plane equation; S6: According to the port power and the state of charge, the plane equation is used to obtain the current amplitude corresponding to the port power and the state of charge, and the state of charge is updated according to the current amplitude and the preset time period.

2. The method according to claim 1, characterized in that The battery initial state information includes: surface lithium concentration of electrode active materials, average lithium concentration of electrode active materials, electrode electrolyte lithium concentration, and initial value of battery temperature.

3. The method according to claim 2, characterized in that The method of obtaining the battery port voltage at each moment within a preset time period according to the battery initial state information and the lithium-ion battery electrochemical model simulation includes: Obtain a battery ambient temperature sequence of constant amplitude, the battery ambient temperature sequence including the battery ambient temperature at each moment within a preset time period, At the start of the preset time period, the parameter vector of the current moment is updated according to the lithium concentration of the electrode electrolyte, the average lithium concentration of the electrode active material and the battery temperature at the previous moment: in, is the parameter vector at the current moment, is the parameter update function, is the lithium concentration of the electrode electrolyte at the previous moment, is the average lithium concentration of the electrode active material at the previous moment, The battery temperature at the last moment; According to the previous moment's electrode electrolyte lithium concentration, electrode active material surface lithium concentration, battery temperature, port current and current moment parameter vector, update the current moment's reaction current intensity: in, is the current intensity of the reaction at the current moment, is the reaction current update function, is the lithium concentration of the electrode electrolyte at the previous moment, is the lithium concentration on the surface of the electrode active material at the previous moment, is the battery temperature at the last moment, is the port current at the previous moment, is the parameter vector at the current moment; According to the current reaction current intensity and parameter vector, update the current electrode surface potential difference: in, is the electrode surface potential difference at the current moment, is the electrode surface potential difference update function, is the current intensity of the reaction at the current moment, is the parameter vector at the current moment; Update the lithium concentration of the electrode active material at the current moment according to the average lithium concentration of the electrode active material at the previous moment, the lithium concentration on the surface of the electrode active material, the reaction current intensity at the current moment, the parameter vector at the current moment and the sampling interval: in, is the average lithium concentration of the electrode active material at the current moment, is the update function of the average lithium concentration of electrode active materials, is the average lithium concentration of the electrode active material at the previous moment, is the lithium concentration on the surface of the electrode active material at the previous moment, is the current intensity of the reaction at the current moment, is the parameter vector at the current moment, is the sampling interval, is the lithium concentration on the surface of the electrode active material at the current moment, is the updated function of lithium concentration on the surface of electrode active materials, is the average lithium concentration of the electrode active material at the previous moment, is the lithium concentration on the surface of the electrode active material at the previous moment, is the current intensity of the reaction at the current moment, is the parameter vector at the current moment, is the sampling interval; Update the current electrode electrolyte lithium concentration based on the previous moment's electrode electrolyte lithium concentration, port current, current moment parameter vector and sampling interval: in, is the lithium concentration of the electrode electrolyte at the current moment, is the electrode electrolyte lithium concentration update function, is the electrode electrolyte lithium concentration at the previous moment, is the port current at the previous moment, is the parameter vector at the current moment, is the sampling interval; According to the current moment of electrode electrolyte lithium concentration, electrode active material surface lithium concentration, reaction current intensity, parameter vector and the battery temperature and port current of the previous moment, the current moment of battery port voltage is obtained. and the potential difference within the battery : in, is the battery port voltage at the current moment, is the battery port voltage update function, is the lithium concentration of the electrode electrolyte at the current moment, is the lithium concentration on the surface of the electrode active material at the current moment, is the current intensity of the reaction at the current moment, is the battery temperature at the last moment, is the port current at the previous moment, is the parameter vector at the current moment, is the potential difference in the battery at the current moment, is the potential difference update function in the battery, is the lithium concentration of the electrode electrolyte at the current moment, is the lithium concentration on the surface of the electrode active material at the current moment, is the current intensity of the reaction at the current moment, is the battery temperature at the last moment, is the port current at the previous moment, is the parameter vector at the current moment; According to the battery port voltage, the potential difference in the battery, the reaction current intensity, the parameter vector and the battery temperature, the ambient temperature, the port current and the sampling interval at the previous moment, the battery temperature at the current moment is obtained: in, is the current battery temperature, is the battery temperature update function, is the battery port voltage at the current moment, is the potential difference in the battery at the current moment, is the current intensity of the reaction at the current moment, is the battery temperature at the last moment, is the ambient temperature at the previous moment, is the port current at the previous moment, is the parameter vector at the current moment, is the sampling interval; Repeat the above simulation iteration update steps, and cyclically update the current state value from the previous state value: parameter vector, reaction current intensity, electrode surface potential difference, electrode active material lithium concentration, electrode electrolyte lithium concentration, and output the battery port voltage and battery temperature according to the state update result until the preset time period ends, so as to obtain the battery port voltage at each moment within the preset time period. The battery port voltage at each moment in the preset time period is expressed as in, is the battery port voltage at each moment within the preset time period, is the voltage value of the battery port at the kth moment, is the battery port voltage value at the Nth moment.

4. The method according to claim 3, characterized in that The calculating the port power corresponding to the initial state of charge according to the battery port voltage and current sequence amplitude includes: The average port voltage within a preset time period is obtained according to the battery port voltage, and the port power corresponding to the initial state of charge and the current sequence amplitude is calculated according to the average port voltage and the current sequence amplitude. Among them, the average port voltage is expressed as: in, is the average port voltage, is the voltage value of the battery port at the kth moment, is the battery port voltage value at the Nth moment, N is the total number of moments in the preset time period, The port power is expressed as: in, is the port power, is the initial state of charge, is the set battery ambient temperature value, is the current sequence amplitude, is the average port voltage.

5. The method according to claim 4, characterized in that The adjusting the initial state of charge and the current sequence amplitude, repeating steps S1-S3, respectively obtaining port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, and obtaining a current amplitude-state of charge-port power surface according to the port power, comprises: While keeping the battery ambient temperature constant, adjust the initial state of charge and current sequence amplitude of the battery, repeat S1-S3, obtain the port powers corresponding to multiple different initial states of charge and current sequence amplitudes, connect the port powers smoothly, and obtain the current amplitude-state of charge-port power surface. Among them, the current amplitude-charge state-port power surface is expressed as: in, for The current amplitude-charge state-port power surface function at is the initial state of charge, is the port power, is the current sequence amplitude, is the set battery ambient temperature value, is the actual ambient temperature of the battery.

6. The method according to claim 5, characterized in that The current amplitude-state of charge-port power surface is fitted into a plane equation, which is expressed as: in, for The current amplitude-charge state-port power surface function at is the initial state of charge, is the port power, is the current sequence amplitude, is the set battery ambient temperature value, is the actual ambient temperature of the battery, A, B, C are the plane fitting coefficients, and D is the plane fitting constant coefficient.

7. The method according to claim 6, characterized in that The method of obtaining the current amplitude corresponding to the port power and the state of charge by using the plane equation according to the port power and the state of charge, and updating the state of charge according to the current amplitude and the preset time period includes: Under the condition of keeping the battery ambient temperature constant, according to the known port power and state of charge, the current amplitude is obtained by using the plane equation. Among them, the current amplitude is expressed as: in, is the current amplitude, is the current amplitude function, is the initial state of charge, is the set ambient temperature value, is the actual ambient temperature of the battery, is the constant coefficient of the current amplitude function, is the current amplitude function The corresponding first-order coefficient is, is the current amplitude function The corresponding first-order coefficient is, is the port power, By plane fitting coefficient Export: Among them, A, B, C are the plane fitting coefficients, and D is the plane fitting constant coefficient. is the constant coefficient of the current amplitude function, is the current amplitude function The corresponding first-order coefficient is, is the current amplitude function The corresponding first-order coefficient; The state of charge is updated according to the current amplitude and the preset time period, which is expressed as: in, is the change in state of charge in adjacent time periods, is the current amplitude, is the total battery capacity in ampere-hours, is the length of the preset time period, N is the total number of moments in the preset time period, is the sampling interval, is the battery charge state at the beginning of the next time period, The battery state of charge at the beginning of this time period.

8. A charge state updating device based on the power characteristics of the electrochemical model of a lithium-ion battery, characterized in that: include: An acquisition module, used for acquiring an initial state of charge of the battery and a current sequence of a constant amplitude; A processing module is used to obtain the initial state information of the battery, and obtain the battery port voltage at each moment in a preset time period according to the initial state information of the battery and the electrochemical model simulation of the lithium-ion battery, wherein the initial state information of the battery includes: the surface lithium concentration of the electrode active material, the average lithium concentration of the electrode active material, the lithium concentration of the electrode electrolyte, and the initial value of the battery temperature; A calculation module, used for calculating the port power corresponding to the initial state of charge according to the battery port voltage and current sequence amplitude; A circulation module, used for adjusting the initial state of charge and the current sequence amplitude, repeatedly calling the acquisition module, the processing module and the calculation module, respectively obtaining the port powers corresponding to a plurality of different initial states of charge and current sequence amplitudes, and obtaining a current amplitude-state of charge-port power surface according to the port power; A fitting module, used for fitting the current amplitude-state of charge-port power surface into a plane equation; The updating module is used to obtain the current amplitude corresponding to the port power and the state of charge by using the plane equation according to the port power and the state of charge, and update the state of charge according to the current amplitude and the preset time period.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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