WO2023138207A1

WO2023138207A1 - Capacity calculation method and device for power battery

Info

Publication number: WO2023138207A1
Application number: PCT/CN2022/133782
Authority: WO
Inventors: 林文煜; 赵微
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-01-24
Filing date: 2022-11-23
Publication date: 2023-07-27
Also published as: CN115825782A; CN115825782B

Abstract

A capacity calculation method and device for a power battery, wherein the method comprises: acquiring a plurality of pieces of charging condition data of a target power battery (101); respectively using, according to each of the plurality of pieces of charging condition data, at least two battery capacity determination methods to obtain the battery capacity corresponding to each of the at least two battery capacity determination methods (102); obtaining target data according to the battery capacity corresponding to each of the at least two battery capacity determination methods (103); and calculating, on the basis of the target data, the battery capacity corresponding to the target power battery at a target time point, wherein the target time point is any time point in the full life cycle of the target power battery (104). By means of the method, the accuracy of power battery capacity calculation can be improved.

Description

A method and device for calculating the capacity of a power battery

Cross References to Related Applications

This application claims the priority of the Chinese patent application 202210079817.7 entitled "A Capacity Calculation Method and Device for Power Batteries" filed on January 24, 2022, the entire content of which is incorporated herein by reference.

technical field

The present application relates to the technical field of power batteries, in particular to a method and device for calculating the capacity of a power battery.

Background technique

With the rapid development of the new energy industry, new energy vehicles have become one of the main means of transportation for people to travel. New energy vehicles mainly use power batteries as the power source, so the capacity of the power battery directly affects the cruising range and performance of the vehicle. During the use of the power battery, with the charge and discharge cycle of the power battery, the capacity of the power battery will decay. In order to avoid the mileage and performance of new energy vehicles being affected by the capacity of the power battery, it is necessary to calculate the capacity of the power battery, and use the calculated capacity to determine whether to replace the power battery.

At present, the capacity calculation of the power battery mainly relies on the neural network model to complete. The neural network model is trained through a large number of charging condition data samples. Then, the charging condition data sample for training the neural network model is easily distorted, resulting in low accuracy of the neural network model in calculating the capacity of the power battery.

Contents of the invention

In view of the above problems, the present application proposes a method and device for calculating the capacity of a power battery, the main purpose of which is to improve the accuracy of calculating the capacity of the power battery.

In a first aspect, the present application provides a capacity calculation method for a power battery, the method comprising: obtaining multiple pieces of charging condition data of a target power battery; using at least two battery capacity determination methods respectively according to each of the multiple pieces of charging condition data to obtain the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods; obtaining target data according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods; calculating the battery capacity corresponding to the target power battery at a target time point based on the target data. The time point is any time point in the whole life cycle of the target power battery.

In the method for calculating the capacity of the power battery provided in the embodiment of the present application, when it is necessary to calculate the capacity of the target power battery, firstly obtain multiple pieces of charging condition data of the target power battery. Then, according to each piece of charging working condition data in the plurality of pieces of charging working condition data, two or more battery capacity determining methods are respectively used to obtain the battery capacity corresponding to each battery capacity determining method. And the target data is obtained according to the battery capacity corresponding to various battery capacity determination methods. Finally, based on the target data, the battery capacity corresponding to the target power battery at the target time point is calculated. It can be seen that the capacity of the target power battery decays with its charge-discharge cycle, so the battery capacity corresponding to the power battery at the target time point calculated in the solution provided by the embodiment of the present application is the battery capacity of the target power battery after decay. When calculating the battery capacity corresponding to the target time point, two or more battery capacity determination methods are combined. While combining the advantages of various battery capacity determination methods, it can get rid of the limitations and deviations of various battery capacity determination methods, so that the calculated battery capacity is closer to the real power of the target power battery, so the embodiment of the present application can improve the accuracy of power battery capacity calculation.

In some embodiments, at least two battery capacity determination methods are used respectively according to each piece of charging condition data in the multiple pieces of charging condition data to obtain the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determining methods, including: using a battery capacity determination method based on the anode phase transition characteristic point of the power battery to determine the battery capacity of each piece of the charging condition data to obtain the first battery capacity corresponding to each piece of the charging condition data; using a battery capacity determination method based on the state of charge of the power battery to determine the battery capacity for each piece of the charging condition data, Obtaining the second battery capacity corresponding to each piece of charging working condition data.

In some embodiments, a battery capacity determination method based on the anode phase transition feature point of the power battery is used to determine the battery capacity of each piece of the charging condition data, and obtain the first battery capacity corresponding to each piece of the charging condition data, including: For each piece of the charging condition data, perform: based on the charging voltage of the target power battery in the charging condition data, determine the first target time point corresponding to the anode phase change feature point of the target power battery; determine the specific first target battery capacity when the target power battery is charged based on the first target time point; The capacity is compensated to obtain the first battery capacity corresponding to the charging condition data.

In some embodiments, determining the first target time point corresponding to the anode phase transition characteristic point of the target power battery based on the charging voltage of the target power battery in the charging working condition data includes: determining a plurality of target charging voltages in the charging working condition data, wherein the charging voltage includes an initial voltage, a first target voltage, and at least one charging voltage between the initial voltage and the first target voltage, wherein the initial voltage is the initial voltage when the first target battery is charged, and the first target voltage is the first target battery in the target power battery when the charging of the target power battery ends. Voltage, the voltage of the first target cell is the smallest among all the cells of the target power battery; based on the plurality of target charging voltages, a differential curve between the target charging voltage and time is generated; a target local maximum point is selected from all local maximum points of the differential curve, wherein the peak width of the target local maximum point is the widest among all local maximum points; the time point corresponding to the target local maximum point is determined as the first target time point.

In some embodiments, determining the specific first target battery capacity at the end of charging of the target power battery based on the first target time point includes: obtaining the first capacity corresponding to the anode phase transition characteristic point of the target power battery; determining the second capacity charged by the target power battery between the first target time point and the second target time point, the second target time point being the time point when the target power battery ends charging; determining the sum of the first capacity and the second capacity as the first target battery capacity.

In some embodiments, determining the second capacity of the target power battery charged between the first target time point and the second target time point includes: performing ampere-hour integral calculation on the current value in the charging condition data between the first target time point and the second target time point to obtain the second capacity.

In some embodiments, performing compensation processing on the first target battery capacity to obtain the first battery capacity corresponding to the charging condition data includes: performing at least one compensation process based on the charging condition data to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of current compensation processing, temperature compensation processing, and full charge compensation processing; compensating the first target battery capacity through the at least one battery capacity compensation value to obtain the first battery capacity.

In some embodiments, compensating the first target battery capacity by using the at least one battery capacity compensation value to obtain the first battery capacity includes: determining the sum of the at least one battery capacity compensation value and the first target battery capacity as the first battery capacity.

In some embodiments, the battery capacity determination method for each piece of charging condition data based on the state of charge of the power battery is used to determine the battery capacity respectively to obtain the second battery capacity corresponding to each piece of the charging condition data, including: For each piece of the charging condition data, perform: determine the second target battery capacity that is charged after the target power battery is discharged to the target state of charge based on the charging condition data; obtain a fourth target battery capacity based on the second target battery capacity and the third target battery capacity corresponding to the target state of charge; perform compensation processing on the fourth target battery capacity to obtain The second battery capacity corresponding to the charging working condition data.

In some embodiments, determining the second target battery capacity charged after the target power battery is discharged to a target state of charge based on the charging condition data includes: determining a third target time point when charging the target power battery starts and a fourth target time point when charging the target power battery ends, wherein the state of charge at the start of charging the target power battery is the target state of charge; performing an ampere-hour integral calculation on the current value between the third target time point and the fourth target time point in the charging condition data to obtain the second target battery capacity.

In some embodiments, obtaining the fourth target battery capacity based on the second target battery capacity and the third target battery capacity corresponding to the target state of charge includes: based on the voltage value corresponding to the preset state of charge, querying the voltage and power curve of the target power battery, and determining the power value corresponding to the voltage value as the third target battery capacity; determining the sum of the second target battery capacity and the third target battery capacity as the fourth target battery capacity.

In some embodiments, performing compensation processing on the fourth target battery capacity to obtain the second battery capacity corresponding to the charging condition data includes: performing at least one compensation process based on the charging condition data to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of temperature compensation processing and full charge compensation processing; compensating the fourth target battery capacity through the at least one battery capacity compensation value to obtain the second battery capacity.

In some embodiments, compensating the fourth target battery capacity by using the at least one battery capacity compensation value to obtain the second battery capacity includes: determining the sum of the at least one battery capacity compensation value and the fourth target battery capacity as the second battery capacity.

In some embodiments, performing current compensation processing based on the charging working condition data, and obtaining the first battery capacity compensation value corresponding to the current compensation processing includes: obtaining the first battery capacity compensation value corresponding to the current compensation processing based on the first current value corresponding to the first target time point in the charging working condition data.

In some embodiments, obtaining the first battery capacity compensation value corresponding to the current compensation processing based on the current value corresponding to the target time point in the charging working condition data includes: obtaining the first battery capacity compensation value through the following formula:

C _{current compensation} ＝C _C ×(Curr _peak -Curr _offset )

Wherein, C _{current compensation} is the first battery capacity compensation value, Curr _peak is the current value corresponding to the first target time point, C _C is the preset current compensation coefficient, and Curr _offset is the preset current calibration value.

In some embodiments, performing temperature compensation processing based on the charging working condition data to obtain a second battery capacity compensation value corresponding to the temperature compensation processing includes: obtaining the second battery capacity compensation value corresponding to the temperature compensation processing based on a target temperature in the charging working condition data, wherein the target temperature is a temperature of a second target battery cell in the target power battery when charging in the target power battery ends, and wherein the temperature of the second target battery cell is the highest among all cells of the target power battery.

In some embodiments, obtaining the second battery capacity compensation value corresponding to the temperature compensation processing based on the first target temperature in the charging working condition data includes: obtaining the second battery capacity compensation value through the following formula:

C _{temperature compensation} = C _t × (Temp _curr -T')

Wherein, C _{temperature compensation} is the second battery capacity compensation value, Temp _curr is the target temperature, T′ is a preset temperature calibration value, and C _t is a preset temperature compensation coefficient.

In some embodiments, performing full charge compensation processing based on the charging condition data to obtain a third battery capacity compensation value corresponding to the full charge compensation process includes: obtaining the third battery capacity compensation value corresponding to the full charge compensation process based on a second target voltage in the charging condition data, wherein the second target voltage is a voltage of a third target cell in the target power battery when charging in the target power battery ends, and wherein the voltage of the third target cell is the highest among all cells of the target power battery.

In some embodiments, obtaining the third battery capacity compensation value corresponding to the full charge compensation process based on the target voltage in the charging working condition data includes: obtaining the third battery capacity compensation value through the following formula:

C _{full charge compensation} ＝C _f ×(Volt _end -Volt _n )

Wherein, C _{full charge compensation} is the third battery capacity compensation value, Volt _end is the second target voltage, Volt _n is a preset full charge calibration value, and C _f1 is a preset full charge compensation coefficient.

In some embodiments, obtaining the target data according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods includes: performing for each of the first battery capacities: extracting the target second battery capacity occurring in a preset time period from each of the second battery capacities; respectively determining the difference between the first battery capacity and each of the target second battery capacities; determining the average value of all the differences; determining the first battery capacity and the average value as a deviation battery capacity; The slope obtained by linear fitting was determined as the target data.

In some embodiments, calculating the battery capacity corresponding to the target power battery at the target time point based on the target data includes: determining a target duration between the target time point and an initial time point, wherein the initial time point is the time point when the target power battery is first put into use; based on the slope, the initial capacity of the second battery power battery, and the target duration, determining the battery capacity of the target power battery at the target duration.

In some embodiments, based on the slope, the initial capacity of the second battery power battery, and the target duration, determining the battery capacity of the target power battery at the target duration includes: determining the battery capacity of the target power battery at the target duration by the following formula:

Cap _predict =k×t+C'

Wherein, the Cap _predict is the battery capacity of the target power battery under the target duration, k is the slope, t is the target duration, and C' is the initial capacity of the second battery power battery.

In a second aspect, the present application provides a capacity calculation device for a power battery, the device comprising: an acquisition unit, configured to acquire multiple pieces of charging condition data of a target power battery; a first determination unit, configured to use at least two battery capacity determination methods respectively according to each piece of charging condition data in the multiple pieces of charging condition data, to obtain the battery capacity corresponding to each of the at least two battery capacity determination methods; a second determination unit, configured to obtain the target data according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods; and a calculation unit, based on the target data, Calculate the battery capacity corresponding to the target power battery at a target time point, wherein the target time point is any time point within the entire life cycle of the target power battery.

In a third aspect, the present application provides a controller, the controller includes a processor and a machine-readable storage medium, the machine-readable storage medium stores machine-executable instructions that can be executed by the processor, and the instructions are loaded and executed by the processor: to implement the method for calculating the capacity of a power battery according to any one of the first aspect.

In a third aspect, the present application provides a vehicle machine, which includes: the controller described in the third aspect.

In a fourth aspect, the present application provides a vehicle, the vehicle comprising: the vehicle machine described in the fourth aspect.

The above description is only an overview of the technical solution of the embodiment of the utility model. In order to understand the technical means of the embodiment of the utility model more clearly, it can be implemented according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the embodiment of the utility model more obvious and easy to understand, the specific implementation modes of the utility model are enumerated below.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the application. Also, the same reference numerals are used to denote the same components throughout the drawings. In the attached picture:

Fig. 1 shows a flow chart of a method for calculating the capacity of a power battery provided by an embodiment of the present application;

FIG. 2 shows a schematic diagram of a relationship curve between a target charging voltage and time provided by an embodiment of the present application;

FIG. 3 shows a schematic diagram of a differential curve between a target charging voltage and time provided by an embodiment of the present application;

Fig. 4 shows a schematic structural diagram of a power battery capacity calculation device provided by an embodiment of the present application;

Fig. 5 shows a schematic structural diagram of a power battery capacity calculation device provided by another embodiment of the present application.

Detailed ways

Embodiments of the technical solutions of the present application will be described in detail below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present application more clearly, and therefore are only examples, rather than limiting the protection scope of the present application.

Unless otherwise defined, all the technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the application; the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the application; the terms "comprising" and "having" in the specification and claims of the application and the description of the above drawings, as well as any variations thereof, are intended to cover non-exclusive inclusion.

In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "plurality" means two or more, unless otherwise specifically defined.

Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The occurrences of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the embodiment of the present application, the term "and/or" is only an association relationship describing associated objects, which means that there may be three kinds of relationships, such as A and/or B, which may mean: A exists, A and B exist at the same time, and B exists. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two groups (including two), and "multiple pieces" refers to more than two (including two).

In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It should not be construed as limiting the embodiments of the present application by implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it may be a fixed connection, or a detachable connection, or integrated; it may also be a mechanical connection, or an electrical connection; it may be a direct connection, or an indirect connection through an intermediary, or an internal communication between two components or an interaction between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific situations.

At present, with the rapid development of the new energy industry, power batteries, as power sources, are widely used in many fields such as electronic communications, transportation, aviation, and household energy storage. In particular, in recent years, new energy vehicles have become one of the main means of transportation for people to travel, and power batteries are widely used in new energy vehicles as a power source.

The inventors of the present invention have noticed that with the charge and discharge cycle of the power battery, the battery capacity of the power battery will fade. The capacity of the power battery directly affects the mileage and performance of the vehicle. Therefore, during the use of the power battery, it is necessary to calculate the capacity of the power battery to determine the attenuation degree of the power battery capacity based on the calculated battery capacity. In order to replace the power battery in time when the battery capacity decays to a certain extent, so as to avoid the mileage and performance of new energy vehicles being affected.

The inventor noticed that at present, the calculation of the capacity of the power battery mainly depends on the neural network model. When calculating the capacity of the power battery, the charging condition data required for calculating the capacity is input into the neural network model, and the capacity of the power battery is calculated by the neural network model. The method of calculating the capacity of the power battery by the neural network model has at least the following two disadvantages: First, the neural network model requires a large amount of data training, and the accuracy of the neural network model largely depends on the quality of the training data and real vehicle input data. The reality is that the vehicle is driving in a place with weak signal. For example, when the vehicle is driving in a tunnel or a place far away from the signal base station, the data collected by the vehicle-end BMS (battery management system, battery management system) cannot be sent to the background storage, resulting in data loss. In the case of serious data loss, the authenticity of the training data will be greatly affected. Second, the training data of the neural network model is usually collected based on a single cell in the power battery, and the generalization of the neural network model is poor. Combining the above two deficiencies, the accuracy of the trained neural network model to calculate the battery capacity of the power battery is not high.

In order to improve the accuracy of power battery capacity calculation, the applicant has found that at least two battery capacity determination methods can be used for power battery capacity calculation, thereby combining the advantages of at least two battery capacity determination methods to improve the power battery capacity calculation accuracy.

Based on the above considerations, in order to improve the accuracy of power battery capacity calculation, the inventor has designed a power battery capacity calculation method after in-depth research, specifically: obtaining multiple pieces of charging condition data of the target power battery. According to each piece of charging working condition data in the multiple pieces of charging working condition data, at least two battery capacity determining methods are respectively used to obtain the battery capacity corresponding to each battery capacity determining method in the at least two battery capacity determining methods. The target data is obtained according to the battery capacity corresponding to each battery capacity determination method in at least two battery capacity determination methods. Based on the target data, the battery capacity corresponding to the target power battery at the target time point is calculated, wherein the target time point is any time point within the entire life cycle of the target power battery.

The power battery capacity calculation method and device disclosed in the embodiments of the present application can be applied to any power battery, and the power battery can be any one of the following electric devices: mobile phones, tablets, notebook computers, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric boat toys, electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles, spaceships, etc.

The controller disclosed in the embodiment of the present application includes a processor and a machine-readable storage medium, the machine-readable storage medium stores machine-executable instructions that can be executed by the processor, and the instructions are loaded and executed by the processor: to realize the capacity calculation method of the power battery disclosed in the embodiment of the present application.

The vehicle machine disclosed in the embodiments of the present application may be applied to, but not limited to, household or commercial vehicles powered by power batteries.

The method and device for calculating the capacity of the power battery, the controller, the vehicle machine, and the vehicle provided in the embodiments of the present application will be described in detail below.

As shown in Figure 1, the embodiment of the present application provides a method for calculating the capacity of a power battery, which mainly includes:

101. Obtain multiple pieces of charging working condition data of the target power battery.

A power battery is a battery used as a power source on an electric device such as a vehicle, and its capacity will decay with the cycle of charging and discharging. The capacity calculated in the embodiment of the present application refers to the capacity of a power battery at a point in its entire life cycle, that is, the capacity that the power battery decays to at that point in time.

The specific type of target power battery can be selected based on specific business needs. In principle, any power battery with capacity calculation requirements can be used as the target power battery. Exemplarily, the target power battery is a lithium iron phosphate battery as a power source of a commercial vehicle, that is, LFP.

The charging condition data is the data of the target power battery under the charging condition, which reflects the specific charging situation of the target power battery. In principle, a corresponding piece of charging condition data will be generated once the target power battery is charged. That is to say, a piece of charging condition data corresponds to the primary charging condition of the target power battery. The charging condition data may include but not limited to at least one or more of the following parameters: the charging voltage of each battery cell of the target power battery and the time point corresponding to the charging voltage, the charging current value and the time point corresponding to the charging current value, multiple states of charge during the charging process of each battery cell and the time points corresponding to the state of charge, and the temperature of each battery cell during the charging process. Wherein, the charging voltage, charging current, state of charge and temperature all refer to values at the beginning of charging, at the end of charging, and between the beginning of charging and the end of charging.

The specific process of obtaining multiple pieces of charging condition data of the target power battery is described below, and the process includes the following steps 1 and 2:

Step 1, data cleaning.

During the use of the target power battery, the BMS of the target power battery will collect the charging condition data of the target power battery, that is, once the target power battery is charged, the BMS collects a piece of charging attack data corresponding to the charge. The BMS sends the collected charging condition data to the preset storage platform for storage. A large amount of charging condition data corresponding to the target power battery is stored in the preset storage platform, and there are usually some abnormalities in these data, which will affect the accuracy of the capacity calculation of the target power battery. Therefore, data cleaning is required to remove the abnormal charging condition data. Abnormal situations include but are not limited to data loss and null values, wherein data loss and null values are usually generated during the process of sending charging condition data to the preset storage platform by the BMS. For example, the transmission between the BMS and the preset storage platform is interrupted, resulting in the unsuccessful transmission of some data in the charging working condition data to the preset storage platform, resulting in the loss of some data in the charging working condition data.

Exemplarily, there is charging working condition data 1 in the preset storage platform, and the charging starting voltage and charging ending voltage of each battery cell are missing in the charging working condition data 1. Because the charging working condition data 1 loses the charging starting voltage and charging ending voltage of each battery cell, it lacks the basic data for calculating the capacity, so it is eliminated.

Step 2, extracting multiple pieces of charging working condition data.

After cleaning the charging condition data in the preset storage platform, all or part of the charging condition data can be extracted and used as the charging condition data for calculating the target power battery capacity.

In practical applications, when extracting the charging working condition data, the charging working condition data can be extracted according to the numerical value of the parameters included in the charging working condition data. The method of extracting the charging condition data according to the numerical value of the parameters included in the charging condition data can avoid using the charging condition data which contributes little to the calculation of the power battery capacity. Theoretically, the more charging conditions data are extracted, the more charging conditions are introduced in the capacity calculation, and the more accurate the capacity calculation of the power battery is.

Exemplarily, in order to use more charging condition data to calculate the capacity of the target power battery, the charging condition data whose initial state of charge is less than 55%, and the maximum voltage of the end-of-charge voltage in each battery cell is greater than 3.5 volts are all extracted as the charging condition data required for calculating the capacity of the target power battery.

102. According to each piece of charging working condition data among the pieces of charging working condition data, respectively adopt at least two battery capacity determining methods, and obtain the battery capacity corresponding to each battery capacity determining method in the at least two battery capacity determining methods.

In order to make up for the calculation deviation of one battery capacity determination method, at least two battery capacity determination methods are selected, and at least two battery capacity determination methods are used to determine the capacity of each charging condition data, and the battery capacity corresponding to each battery capacity determination method is obtained.

It should be noted that, for any battery capacity determination method, it is necessary to use the circuit capacity determination method to determine the capacity of each piece of charging condition data to obtain the battery capacity corresponding to each piece of charging condition data. Therefore, the battery capacity corresponding to a battery capacity determining method is the battery capacity corresponding to each piece of charging working condition data obtained after the battery capacity determining method determines the capacity of each piece of charging working condition data. Exemplarily, there are three pieces of charging condition data of the target power battery: charging condition data 1, charging condition data 2 and charging condition data 3, which are processed by battery capacity determination method 1 and battery capacity determination method 2. The battery capacity corresponding to the battery capacity determination method 1 is: the battery capacity corresponding to the charging condition data 1, the battery capacity corresponding to the charging condition data 2, and the battery capacity corresponding to the charging condition data 3. The battery capacity corresponding to the battery capacity determination method 2 is: the battery capacity corresponding to the charging condition data 1, the battery capacity corresponding to the charging condition data 2, and the battery capacity corresponding to the charging condition data 3.

In practical applications, the number and types of battery capacity determination methods can be determined based on business requirements, which are not specifically limited in this embodiment, examples are as follows:

Exemplarily, the following two battery capacity determination methods are selected: a battery capacity determination method based on the phase transition characteristic point of the anode of the power battery and a battery capacity determination method based on the state of charge of the power battery.

Exemplarily, the following three battery capacity determination methods are selected: a battery capacity determination method based on the anode phase transition characteristic point of the power battery, a battery capacity determination method based on the state of charge of the power battery, and a battery capacity determination method based on a neural network model.

103. Obtain target data according to the battery capacity corresponding to each battery capacity determination method in at least two battery capacity determination methods.

Since each battery capacity determination method has different deviations and variances in determining the battery capacity, in order to improve the accuracy of target battery capacity calculation, it is necessary to fuse the battery capacities corresponding to various battery capacity determination methods. The process of fusing battery capacities corresponding to various battery capacity determination methods is mainly a process of determining target data. The target data is key data used to calculate the capacity of the target power battery, which represents the decay rate of the capacity of the target power battery with time.

The key point in the process of obtaining the target data according to the battery capacity corresponding to each battery capacity determination method in at least two battery capacity determination methods is to obtain a set of battery capacities with less deviation based on the battery capacities corresponding to various battery capacity determination methods. A linear fitting is performed on the obtained battery capacity with less deviation to determine the decay of the battery capacity with time. The slope of the curve formed after the linear fitting is determined as the target data, and the slope represents the decay rate of the capacity of the target power battery with time.

104. Based on the target data, calculate the battery capacity corresponding to the target power battery at the target time point, wherein the target time point is any time point within the entire life cycle of the target power battery.

Based on the target data, the specific process of calculating the battery capacity corresponding to the target power battery at the target time point includes: determining the target duration between the target time point and the initial time point, wherein the initial time point is the time point when the target power battery is put into use for the first time. Based on the slope, the initial capacity of the second power battery and the target duration, the battery capacity of the target power battery under the target duration is determined.

During the whole life cycle of the target power battery, with the charge and discharge cycle, the battery capacity of the target power battery will experience capacity decay. During the use of the target power battery, if it is necessary to know the degree of capacity decay at any time point in the entire life cycle, this time point can be determined as the target time point to calculate the battery capacity corresponding to the target power battery at the target time point. The initial time point is the time point when the target power battery is put into use for the first time, that is, the time point when the target power battery undergoes a charge-discharge cycle for the first time. The target duration between the target time point and the initial time point is the cumulative usage time of the target power battery in the entire life cycle.

In the embodiment of the present application, based on the slope, the initial capacity of the second battery power battery, and the target duration, the specific process of determining the battery capacity of the target power battery at the target duration is as follows: determine the battery capacity of the target power battery at the target duration by the following formula:

Cap _predict =k×t+C';

Among them, Cap _predict is the battery capacity of the target power battery under the target duration, k is the slope, t is the target duration, and C′ is the initial capacity of the target power battery.

The slope k represents the decay rate of the battery capacity over time, which is obtained by combining the battery capacities corresponding to at least two battery capacity determination methods, so it can truly represent the decay of the battery capacity of the power battery over time. The target duration is the duration between the target time point and the initial time point, which represents the cumulative usage time of the target power battery in the entire life cycle, and the capacity of the target power battery decays within the target time length. The battery capacity calculated based on the target duration is the remaining capacity after the target power battery capacity decays. The initial capacity of the target battery power battery is the capacity of the target power battery when it is put into use for the first time.

Because the target data used for calculating the battery capacity corresponding to the target time point is obtained by combining two or more battery capacity determination methods. Therefore, it can truly represent the decay rate of the capacity of the target power battery over time, so the battery capacity calculated based on the target data can reflect the real capacity of the target power battery at the target time point.

The above-mentioned step 102 is described in detail below:

In some embodiments of the present application, step 102 adopts at least two battery capacity determination methods according to each piece of charging condition data in the plurality of charging condition data, and obtains the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods. The specific process includes the following steps 201 to 202:

201. Using a battery capacity determination method based on the characteristic points of the anode phase transition of the power battery, respectively determine the battery capacity for each piece of charging condition data, and obtain the first battery capacity corresponding to each piece of charging condition data.

The battery capacity determination method based on the characteristic points of the phase transition of the anode of the power battery is a method of calculating the battery capacity by determining the characteristic points of the phase transition of the anode of the power battery. The key point of this method is to determine the characteristic point of the anode phase transition of the target power battery.

The anode phase transition characteristic point is a characteristic point of the power battery. Under the same charging current and the same aging degree, when the power battery is charged to the anode phase transition characteristic point, its battery capacity is a constant. Therefore, when the battery capacity determination method based on the anode phase transition characteristic point of the power battery is used to determine the capacity for any piece of charging condition data, after the anode phase transition characteristic point is determined, it is not necessary to calculate the battery capacity before the anode phase transition characteristic point, but only need to calculate the battery capacity after the anode phase transition characteristic point.

202. Using a battery capacity determination method based on the state of charge of the power battery, respectively determine the battery capacity for each piece of charging condition data, and obtain the second battery capacity corresponding to each piece of charging condition data.

The battery capacity determination method based on the state of charge of the power battery is a method of calculating the battery capacity by determining the state of charge of the power battery specific to the power battery. The key point of this method is to determine the specific state of charge of the power battery.

The state of charge of the power battery specific to the power battery is the state of charge corresponding to the start of charging of the target power battery, and the state of charge is a corresponding state of charge when the discharge of the target power battery stops before the current charging. The state of charge is a state of charge that affects the normal use of the power battery, and it can be flexibly set based on business requirements. The battery capacity corresponding to the state of charge is a constant. Therefore, when the battery capacity determination method based on the state of charge of the power battery determines the capacity for any piece of charging condition data, it is not necessary to calculate the battery capacity before the state of charge, but only the charged battery capacity after the state of charge is calculated. After the battery capacity after the preset state of charge is calculated, the sum of the calculated battery capacity and the constant corresponding to the state of charge can be determined as the second battery capacity corresponding to the charging condition data.

Step 201 to step 202 are described in detail below:

In some embodiments of the present application, the above step 201 adopts the battery capacity determination method based on the anode phase transition characteristic point of the power battery to determine the battery capacity of each piece of charging condition data respectively, and obtain the first battery capacity corresponding to each piece of charging condition data. The specific execution process includes:

For each piece of charging condition data, the following steps 201A to 201C are performed:

201A. Based on the charging voltage of the target power battery in the charging condition data, determine the first target time point corresponding to the anode phase transition characteristic point of the target power battery.

201B. Determine the specific first target battery capacity at the end of charging of the target power battery based on the first target time point.

201C. Perform compensation processing on the first target battery capacity to obtain the first battery capacity corresponding to the charging condition data.

The above steps 201A to 201C are described in detail below:

In some embodiments of the present application, the specific process of determining the first target time point corresponding to the anode phase transition characteristic point of the target power battery in the above step 201A based on the charging voltage of the target power battery in the charging working condition data includes: determining multiple target charging voltages in the charging working condition data, and generating a differential curve between the target charging voltage and time based on the multiple target charging voltages. Select the target local maximum point from all local maximum points of the differential curve. The time point corresponding to the target local highest point is determined as the first target time point. Wherein, the multiple target charging voltages include an initial voltage, a first target voltage, and at least one charging voltage between the initial voltage and the first target voltage, wherein the initial voltage is the initial voltage when charging the first target battery, and the first target voltage is the voltage of the first target battery in the target power battery when the charging of the target power battery ends, and the voltage of the first target battery is the smallest among all the batteries of the target power battery. The peak width of the target local maximum is the widest among all local maximums.

The primary charging condition of the target power battery corresponds to a piece of charging condition data. The charging condition data includes the initial voltage of each cell in the target power battery when charging, the first target voltage at the end of charging, multiple charging voltages during the charging process, the initial voltage, the first target voltage, and the time point when each charging voltage occurs. Wherein, the time points at which the multiple charging voltages occur are located between the time points of the initial voltage and the time points of the first target voltage, and there is a certain time interval between the charging voltages.

When determining the first target time point corresponding to the anode phase transition characteristic point of the target power battery, it is first necessary to select the first target cell in the target power battery, and the first target cell is the cell with the minimum voltage at the end of charging among all the cells of the target power battery. Because the capacity of the power battery is usually determined by the cell with the lowest voltage, the cell with the smallest voltage at the end of charging is selected as the first target cell.

After the first target cell is selected, the initial voltage of the first target cell, the first target voltage, and the charging voltage between the initial voltage and the first target voltage are all selected as the target charging voltage, and based on each target charging voltage and a time point at which each target charging voltage occurs, a relationship curve between the target charging voltage and time is generated. As shown in Figure 2, it is the relationship curve between the target charging voltage and time.

After determining multiple target charging voltages, differential processing is performed on all target charging voltages and times to generate a differential curve between target charging voltages and times, namely

curve. As shown in Figure 3, it is the differential curve between the target charging voltage and time.

In practical applications, such as the charging of power batteries in vehicles, segmental charging is used to achieve safe and fast charging, so the current switching of segmental charging will bring multiple local peaks to the differential curve. In addition, when the charging of the power battery reaches the characteristic point of the anode phase transition, it will also bring a local maximum point to the differential curve. Therefore, after generating the differential curve between the target charging voltage and time, it is necessary to determine all the local maximum points in the differential curve, so as to select the local maximum point caused by the characteristic point of the anode phase transition among all the local maximum points.

In order to ensure the stability of power battery charging, the jump of the target charging voltage caused by the current switching of segmental charging usually occurs in a short time, and the peak width of the local peak caused by it is narrow. However, the jump of the target charging voltage caused by the anode phase transition usually lasts for a long time, and the peak width of the local peak caused by it is relatively wide. Therefore, the local maximum point with the widest peak width is selected from all local maximum points of the differential curve as the target local maximum point, and the target local maximum point is the characteristic point of the anode phase transition. As shown in Figure 3, point A in Figure 3 is the local highest point of the target.

After selecting the target local maximum point from all the local maximum points of the differential curve, the time point corresponding to the target local maximum point is determined as the first target time point, and the first target time point is the time point when the characteristic point of the anode phase transition occurs. The first target time point is obtained based on the relationship curve between the target charging voltage and time and the corresponding relationship of the time axis in the differential curve between the target charging voltage and time.

In some embodiments of the present application, the specific process of determining the specific first target battery capacity at the end of charging of the target power battery based on the first target time point in step 201B includes: obtaining the first capacity corresponding to the anode phase transition characteristic point of the target power battery. Determine the second capacity of the target power battery charged between the first target time point and the second target time point. The sum of the first capacity and the second capacity is determined as the first target battery capacity. Wherein, the second target time point is the time point when the target power battery finishes charging.

The anode phase transition characteristic point is a characteristic point of the power battery. Under the same charging current and the same aging degree, when the power battery is charged to the anode phase transition characteristic point, its battery capacity is a constant. Therefore, after the anode phase transition feature point of the target power battery is determined, the first capacity corresponding to the anode phase transition feature point of the target power battery can be directly obtained by searching from the preset table of correspondence between anode phase transition point and capacity.

After determining the characteristic point of the anode phase transition, instead of calculating the battery capacity before the characteristic point of the anode phase transition, the first capacity corresponding to the characteristic point of the anode phase transition can be obtained by looking up the preset table. Therefore, it is only necessary to calculate the battery capacity after the characteristic point of the anode phase transition. The second capacity of this application is the battery capacity charged by the power battery after the characteristic point of the anode phase transition.

The second capacity is the charging capacity of the target power battery between the first target time point and the second target time point. Wherein, the first target time point is the time point when the target power battery reaches the characteristic point of the anode phase transition, and the second target time point is the time point when the target power battery finishes charging.

In the embodiment of the present application, the specific process of determining the second capacity of the target power battery charged between the first target time point and the second target time point is: performing an ampere-hour integral calculation on the current value between the first target time point and the second target time point in the charging condition data to obtain the second capacity.

Specifically, the ampere-hour integral calculation is performed on the current value between the first target time point and the second target time point in the charging condition data, and the process of obtaining the second capacity can be expressed by the following formula:

Wherein, Cap _{after_phase} is the second capacity, t _end is the second target time point, t _phase is the first target time point, It is the current value corresponding to the time point t, and I _t-1 is the current value corresponding to the time point t-1.

In some embodiments of the present application, step 201C performs compensation processing on the first target battery capacity, and the specific process of obtaining the first battery capacity corresponding to the charging condition data includes the following steps 201C1 to 201C2:

201C1. Perform at least one compensation process based on the charging condition data to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of current compensation process, temperature compensation process, and full charge compensation process.

During the charging process of the target power battery, the charging current, temperature, and voltage at full charge will all bring certain deviations to the battery capacity. Therefore, in order to reduce the existence of deviations and improve the accuracy of battery capacity calculation, at least one compensation process needs to be performed based on the charging condition data.

In practical applications, the at least one compensation process may be selected from at least one of the following: at least one of current compensation process, temperature compensation process and full charge compensation process. When each compensation processing is performed based on the charging working condition data, a battery capacity compensation value corresponding to each compensation processing will be obtained.

The current compensation process is a compensation method based on the current value of the charging condition. The temperature compensation process is based on the compensation method based on the relative temperature of the charging condition. The full charge compensation process is based on the full charge voltage compensation method.

201C2. Compensate the first target battery capacity by using at least one battery capacity compensation value to obtain the first battery capacity.

The purpose of compensating the first target battery capacity by the battery capacity compensation value is to obtain the first battery capacity closer to the real capacity of the target power battery.

The process of compensating the first target battery capacity by using at least one battery capacity compensation value usually includes adding each battery capacity compensation value to the first target battery capacity, and determining the sum result as the first battery capacity.

The specific compensation process in the above step 201C1 is described below:

In some embodiments of the present application, the specific process of performing current compensation processing based on the charging working condition data and obtaining the first battery capacity compensation value corresponding to the current compensation processing includes: obtaining the first battery capacity compensation value corresponding to the current compensation processing based on the first current value corresponding to the first target time point in the charging working condition data. The first target time point is the time point when the target power battery reaches the characteristic point of the anode phase transition.

In the embodiment of the present application, based on the current value corresponding to the target time point in the charging working condition data, the first battery capacity compensation value corresponding to the current compensation processing is obtained, which can be expressed by the following formula:

C _{current compensation} = C _C × (Curr _peak -Curr _offset );

The current value corresponding to the first target time point where the characteristic point of the anode phase transition is located is Curr _peak . The preset current compensation coefficient is calibrated based on a large amount of power battery experimental data, and can be set based on specific business needs. For example, according to the experimental data of the same power battery as the target power battery, a linear relationship is generated from the voltage differential peak value to the total capacity of the full charge under different charging gears, and the preset current compensation coefficient is obtained based on the linear relationship. Similarly, the preset current calibration value is calibrated based on a large amount of power battery experimental data, and can be set based on specific business needs.

In some embodiments of the present application, the specific process of performing temperature compensation processing based on the charging working condition data to obtain the second battery capacity compensation value corresponding to the temperature compensation processing includes: obtaining the second battery capacity compensation value corresponding to the temperature compensation processing based on the target temperature in the charging working condition data, wherein the target temperature is the temperature of the second target cell in the target power battery at the end of charging in the target power battery, wherein the temperature of the second target cell is the highest among all cells of the target power battery.

The same battery cell can be charged with different capacities at different temperatures, so it is necessary to introduce temperature compensation processing to accurately calculate the true capacity of the target power battery. The rechargeable capacity of the target power battery is determined by the second target cell with the highest temperature at the end of charging, so the temperature compensation process is performed based on the temperature of the second target cell. In the embodiment of the present application, this kind of temperature compensation processing can correctly calculate the real capacity of the power battery of commercial vehicles such as buses that run all year round.

In the embodiment of the present application, based on the first target temperature in the charging working condition data, the second battery capacity compensation value corresponding to the temperature compensation processing is obtained, which can be expressed by the following formula:

C _{temperature compensation} = C _t × (Temp _curr -T');

Wherein, C _{temperature compensation} is a second battery capacity compensation value, Temp _curr is a target temperature, T′ is a preset temperature calibration value, and C _t is a preset temperature compensation coefficient.

When the charging of the target power battery ends, the temperature of the second target cell with the highest temperature is the target temperature. The preset temperature compensation coefficient is calibrated based on a large amount of power battery experimental data, and can be set based on specific business needs. Similarly, the target temperature is calibrated based on a large amount of power battery experimental data and can be set based on specific business needs. For example, the target temperature can be the ambient temperature of the power battery at the target point, 25°C.

In some embodiments of the present application, the full charge compensation process is performed based on the charging working condition data, and the specific process of obtaining the third battery capacity compensation value corresponding to the full charge compensation process includes: obtaining the third battery capacity compensation value corresponding to the full charge compensation process based on the second target voltage in the charging working condition data, wherein the second target voltage is the voltage of the third target battery cell in the target power battery when charging in the target power battery ends, and the voltage of the third target battery cell is the highest among all the cells of the target power battery.

In the embodiment of this application, based on the target voltage in the charging condition data, the third battery capacity compensation value corresponding to the full charge compensation process is obtained, which can be expressed by the following formula:

C _{full compensation} = C _f × (Volt _end -Volt _n );

Wherein, C _{full charge compensation} is the third battery capacity compensation value, Volt _end is the second target voltage, Volt _n is the preset full charge calibration value, and C _f is the preset full charge compensation coefficient.

When the charging of the target power battery ends, the voltage of the third target cell with the highest voltage is the second target voltage. The preset full charge compensation coefficient is calibrated based on a large number of power battery experimental data and can be set based on specific business needs. For example, in order to obtain more effective charging cycles, the filter condition for full charging is set as long as the maximum voltage at the end exceeds 3.5V, it is judged as full charging, and the remaining capacity is obtained by linear fitting of the charging capacity of the maximum voltage intercepted during the historical charging process of a single vehicle during the period of 3.5V-3.7V. C _f . Similarly, the preset full-charge calibration value is calibrated based on a large number of power battery experimental data and can be set based on specific business needs.

The above steps 201C2 are described below:

In some embodiments of the present application, the specific process of step 201C2 compensating the first target battery capacity with at least one battery capacity compensation value to obtain the first battery capacity includes: the sum of at least one battery capacity compensation value and the first target battery capacity is determined as the first battery capacity.

Exemplarily, the at least one capacitance compensation value includes a first battery capacity compensation value corresponding to current compensation processing, a second battery capacity compensation value corresponding to temperature compensation processing, and a third battery capacity compensation value corresponding to full charge compensation processing. Then the first battery capacity can be determined by the following formula:

C′ ₁ =C ₁ +C _{current compensation} +C _{temperature compensation} +C _{full compensation} ;

Among them, _C'1 is the first battery capacity, _C1 is the first target battery capacity, C _{current compensation} is the first battery capacity compensation value, C _{temperature compensation} is the second battery capacity compensation value, and C _{full charge compensation} is the third battery capacity compensation value.

The following is an explanation of the above-mentioned non-going 202:

In some embodiments of the present application, step 202 uses a battery capacity determination method based on the state of charge of the power battery to determine the battery capacity for each piece of charging condition data, and the specific process of obtaining the second battery capacity corresponding to each piece of charging condition data includes:

For each piece of charging condition data, the following steps 202A to 202C are performed:

202A. Determine the second target battery capacity charged after the target power battery is discharged to the target state of charge based on the charging working condition data.

202B. Obtain a fourth target battery capacity based on the second target battery capacity and the third target battery capacity corresponding to the target state of charge.

202C. Perform compensation processing on the fourth target battery capacity to obtain a second battery capacity corresponding to the charging working condition data.

The above-mentioned steps 202A to 202C are described in detail below:

In some embodiments of the present application, the above-mentioned step 202A determines the second target battery capacity charged after the target power battery is discharged to the target state of charge based on the charging condition data. The specific process includes: determining the third target time point when the target power battery is charged and the fourth target time point when the target power battery is charged; performing an ampere-hour integral calculation on the current value between the third target time point and the fourth target time point in the charging condition data to obtain the second target battery capacity.

The target state of charge is the state of charge of the target power battery at the beginning of charging, that is, the target state of charge is the state of charge of the target power battery after the last discharge before the current charge. When the target power battery is currently being charged, it is charged with the target state of charge as the initial state of charge. The second target battery capacity is the amount of electricity charged into the target power battery after it has the target state of charge. It should be noted that the target state of charge is generally the lowest target state of charge of the traction battery that can be discharged, and the discharge of the traction battery lower than the target state of charge will cause damage to the traction battery.

Specifically, the ampere-hour integral calculation is performed on the current value between the third target time point and the fourth target time point in the charging condition data, and the process of obtaining the second target battery capacity can be expressed by the following formula:

Wherein, Cap ₁ is the second target battery capacity, t _end is the fourth target time point when the charging of the target power battery ends, t _begin is the third target time point when the target power battery charging starts, It is the current value corresponding to the time point t between the third target time point and the fourth target time point, and It _-1 is the current value corresponding to the time point t-1 between the third target time point and the fourth target time point.

In some embodiments of the present application, the above-mentioned step 202B is based on the second target battery capacity and the third target battery capacity corresponding to the target state of charge, and the specific process of obtaining the fourth target battery capacity includes: based on the voltage value corresponding to the target state of charge, querying the voltage and power curve of the target power battery, and determining the power value corresponding to the voltage value as the third target battery capacity; determining the sum of the second target battery capacity and the third target battery capacity as the fourth target battery capacity.

The battery capacity of the target power battery in the target state of charge is constant, so the voltage and power curve of the target power battery can be queried based on the voltage value corresponding to the target state of charge, and the power value corresponding to the voltage value is determined as the third target battery capacity. The third target battery capacity is the battery capacity of the target power battery in the target state of charge.

The second target battery capacity is the amount of electricity charged into the target power battery after it has the target state of charge. The third target battery capacity is the battery capacity of the target power battery in the target state of charge. Therefore, the sum of the second target battery capacity and the third target battery capacity is determined as the fourth target battery capacity. The fourth target battery capacity is the capacity of the target power battery after charging is completed under a charging condition.

In some embodiments of the present application, the above step 202C performs compensation processing on the fourth target battery capacity, and the specific process of obtaining the second battery capacity corresponding to the charging condition data includes the following steps 202C1 to 202C2:

202C1. Perform at least one compensation process based on the charging condition data to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of temperature compensation process and full charge compensation process.

During the charging process of the target power battery, the charging current and temperature will bring a certain deviation to the battery capacity. Therefore, in order to reduce the storage of deviations and improve the accuracy of battery capacity calculation, at least one compensation process needs to be performed based on the charging condition data.

In practical applications, the at least one compensation process may be selected from at least one of the following: at least one of temperature compensation process and full-fill compensation process. When each compensation processing is performed based on the charging working condition data, a battery capacity compensation value corresponding to each compensation processing will be obtained.

The temperature compensation process is based on the compensation method based on the relative temperature of the charging condition. The full charge compensation process is based on the full charge voltage compensation method.

202C2. Compensate the fourth target battery capacity by using at least one battery capacity compensation value to obtain the second battery capacity.

The specific compensation process in the above step 202C1 is described below:

C _{temperature compensation} = C _t × (Temp _curr -T');

In the embodiment of the present application, based on the target voltage in the charging condition data, the third battery capacity compensation value corresponding to the full charge compensation process is obtained, which can be expressed by the following formula:

C _{full compensation} = C _f × (Volt _end -Volt _n );

Wherein, C _{full charge compensation} is the third battery capacity compensation value, Volt _end is the second target voltage, Volt _n is the preset full charge calibration value, and C _f1 is the preset full charge compensation coefficient.

The above step 202C2 is described below:

In some embodiments of the present application, the specific process of step 202C2 compensating the fourth target battery capacity by at least one battery capacity compensation value to obtain the second battery capacity includes: the sum of at least one battery capacity compensation value and the fourth target battery capacity is determined as the second battery capacity.

Exemplarily, the at least one capacity compensation value includes a second battery capacity compensation value corresponding to temperature compensation processing and a third battery capacity compensation value corresponding to full charge compensation processing. Then the second battery capacity can be determined by the following formula:

C′ ₂ =C ₂ +C _{temperature compensation} +C _{full compensation} ;

Among them, C' ₂ is the second battery capacity, C ₂ is the fourth target battery capacity, C _{current compensation} is the first battery capacity compensation value, C _{temperature compensation} is the second battery capacity compensation value, C _{full charge compensation} is the third battery capacity compensation value.

The above-mentioned step 103 is described in detail below:

In some embodiments of the present application, the specific process of step 103 to obtain target data according to the battery capacity corresponding to each battery capacity determination method in at least two battery capacity determination methods includes the following steps 301 to 303:

301. Execute for each first battery capacity: extract the target second battery capacity occurring in a preset time period from each second battery capacity; respectively determine the difference between the first battery capacity and each target second battery capacity; determine the average value of all the differences; determine the first battery capacity and the average value as the deviation battery capacity.

302. Perform linear fitting on the deviation battery capacities of all first battery capacities and the occurrence time of each first battery capacity.

303. Determine the slope obtained by the linear fitting as the target data.

The above steps 301 to 303 are described in detail below:

In some embodiments of the present application, step 301 is performed for each first battery capacity: extracting target second battery capacities that occur within a preset time period from each second battery capacity; respectively determining the difference between the first battery capacity and each target second battery capacity; determining the average value of all differences; determining the first battery capacity and the average value as the deviation battery capacity.

Various battery capacity determination methods have different deviations and variances in calculating battery capacity, so it is necessary to combine the calculation advantages of various battery capacity determination methods to calculate battery capacity, so as to reduce the deviation and variance of the calculated battery capacity as much as possible. For example, the first battery capacity is obtained by a battery capacity determination method based on the characteristic point of phase transition of the anode of the power battery, and its deviation and variance are relatively large. The second battery capacity is obtained based on the battery capacity determination method of the state of charge of the power battery, and its deviation is small and the variance is large.

Combining various battery capacity determination methods to calculate the calculation advantage of the battery capacity is as follows: for each first battery capacity: extract the target second battery capacity occurring in a preset time period from each second battery capacity; respectively determine the difference between the first battery capacity and each target second battery capacity; determine the average value of all differences; determine the first battery capacity and the average value as the deviation battery capacity. This process is to minimize the bias and variance between the first battery capacity and the second battery capacity.

Exemplarily, for a first battery capacity occurring in May, the second battery capacity occurring in the time period "January to June" is extracted as the target second battery capacity. The difference between the first battery capacity and each target second battery capacity is then determined, and the difference is then divided by the sum of the target second battery capacities to obtain an average of all differences. The first battery capacity and the average value are determined as the deviation battery capacity. Such an operation can reduce the bias and variance between the first battery capacity and the second battery capacity.

In some embodiments of the present application, the specific process of step 302 performing linear fitting on the deviation battery capacity of all first battery capacities and the occurrence time of each first battery capacity is: determining the time point corresponding to each first battery capacity, wherein each first battery capacity has a corresponding time point, and this time point is the time point at which the charging condition data for calculating the first battery capacity occurs. The deviation battery capacity of all the first battery capacities and the occurrence time of each first battery capacity are linearly fitted to obtain a curve of the first battery capacity and time, which reflects the change of the battery capacity with time.

In some embodiments of the present application, the specific process of determining the slope obtained by the linear fitting as the target data in step 303 is: determining the slope obtained by the linear fitting as the target data. Linear fitting reflects the decay of battery capacity over time, so its slope can represent the decay rate of battery capacity over time, so the slope is determined as the target data.

The above-mentioned step 104 is described below:

In some embodiments of the present application, step 104 is based on the target data, and the specific process of calculating the battery capacity corresponding to the target power battery at the target time point includes: determining the target duration between the target time point and the initial time point, wherein the initial time point is the time point when the target power battery is put into use for the first time. Based on the slope, the initial capacity of the second power battery and the target duration, the battery capacity of the target power battery under the target duration is determined.

During the whole life cycle of the target power battery, with the charge and discharge cycle, the battery capacity of the target power battery will experience capacity decay. During the use of the target power battery, if it is necessary to know the degree of capacity decay at any time point in the entire life cycle, this time point can be determined as the target time point to calculate the battery capacity corresponding to the target power battery at the target time point. The initial time point is the time point when the target power battery is put into use for the first time, that is, the time point when the target power battery performs a charge-discharge cycle for the first time. The target duration between the target time point and the initial time point is the cumulative usage time of the target power battery in the entire life cycle.

Cap _predict =k×t+C';

The slope k represents the decay rate of the battery capacity over time, which is obtained by combining the battery capacities corresponding to at least two battery capacity determination methods, so it can truly represent the decay of the battery capacity of the power battery over time. The unit of the slope k can be Ah/s or Ah/h.

The target duration is the duration between the target time point and the initial time point, which represents the cumulative usage time of the target power battery in the entire life cycle, and the capacity of the target power battery decays within the target time length. The battery capacity calculated based on the target duration is the remaining capacity after the target power battery capacity decays. The unit of the target duration can be seconds.

The initial capacity of the target battery power battery is the capacity of the target power battery when it is put into use for the first time.

Exemplarily, the slope is -2Ah/H, the target duration is 50 hours, and the initial capacity is 50000Ah, then

Cap _predict ＝-2×50+50000＝49900;

Further, according to the above method embodiment, another embodiment of the present application also provides a power battery capacity calculation device, as shown in Figure 4, the device includes:

The acquisition unit 41 is used to obtain a plurality of pieces of charging condition data of the target power battery; the first determination unit 42 is used to respectively adopt at least two battery capacity determination methods according to each piece of charging condition data in the plurality of pieces of charging condition data, and obtain the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods; the second determination unit 43 is used to obtain the target data according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods; the calculation unit 44 is used to calculate the battery capacity corresponding to the target power battery at the target time point based on the target data, wherein , the target time point is any time point in the whole life cycle of the target power battery.

The power battery capacity calculation device provided in the embodiment of the present application, when it is necessary to calculate the capacity of the target power battery, first obtains multiple pieces of charging condition data of the target power battery. Then, according to each piece of charging working condition data in the plurality of pieces of charging working condition data, two or more battery capacity determining methods are respectively used to obtain the battery capacity corresponding to each battery capacity determining method. And the target data is obtained according to the battery capacity corresponding to various battery capacity determination methods. Finally, based on the target data, the battery capacity corresponding to the target power battery at the target time point is calculated. It can be seen that the capacity of the target power battery decays with its charge-discharge cycle, so the battery capacity corresponding to the power battery at the target time point calculated in the solution provided by the embodiment of the present application is the battery capacity of the target power battery after decay. When calculating the battery capacity corresponding to the target time point, two or more battery capacity determination methods are combined. While combining the advantages of various battery capacity determination methods, it can get rid of the limitations and deviations of various battery capacity determination methods, so that the calculated battery capacity is closer to the real power of the target power battery, so the embodiment of the present application can improve the accuracy of power battery capacity calculation.

In some embodiments of the present application, as shown in FIG. 5 , the first determination unit 42 includes: a first determination subunit 421, configured to determine the battery capacity of each piece of charging condition data by using a battery capacity determination method based on the anode phase transition characteristic point of the power battery, and obtain the first battery capacity corresponding to each piece of charging condition data; a second determination subunit 422, used to determine the battery capacity of each piece of charging condition data by using a battery capacity determination method based on the state of charge of the power battery, and obtain the second battery capacity corresponding to each piece of charging condition data.

In some embodiments of the present application, as shown in FIG. 5 , the first determining subunit 421 is specifically configured to execute for each piece of charging working condition data: based on the charging voltage of the target power battery in the charging working condition data, determine the first target time point corresponding to the anode phase transition feature point of the target power battery; determine the specific first target battery capacity at the end of charging of the target power battery based on the first target time point; perform compensation processing on the first target battery capacity to obtain the first battery capacity corresponding to the charging working condition data.

In some embodiments of the present application, as shown in FIG. 5 , the first determining subunit 421 includes: a first determining module 421A, configured to determine a plurality of target charging voltages in the charging working condition data, wherein the charging voltage includes an initial voltage, a first target voltage, and at least one charging voltage between the initial voltage and the first target voltage, wherein the initial voltage is the initial voltage when charging the first target battery cell, and the first target voltage is the voltage of the first target battery cell in the target power battery when the charging of the target power battery ends, and the voltage of the first target battery cell is the smallest among all the battery cells of the target power battery; The module 421B is used to generate a differential curve between the target charging voltage and time based on multiple target charging voltages; the selection module 421C is used to select the target local maximum point from all the local maximum points of the differential curve, wherein the peak width of the target local maximum point is the widest among all the local maximum points; the second determination module 421D is used to determine the time point corresponding to the target local maximum point as the first target time point.

In some embodiments of the present application, as shown in FIG. 5 , the first determination subunit 421 includes: an acquisition module 421E, configured to acquire the first capacity corresponding to the anode phase transition characteristic point of the target power battery; a third determination module 421F, used to determine the second capacity of the target power battery charged between the first target time point and the second target time point, and the second target time point is the time point when the target power battery ends charging; a fourth determination module 421G, used to determine the sum of the first capacity and the second capacity as the first target battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the second determination module 421F is specifically configured to perform an ampere-hour integral calculation on the current value between the first target time point and the second target time point in the charging condition data to obtain the second capacity.

In some embodiments of the present application, as shown in FIG. 5 , the first determining subunit 421 includes: a first compensation module 421H, configured to perform at least one compensation process based on the charging condition data, to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of current compensation processing, temperature compensation processing, and full charge compensation processing; a second compensation module 421I, configured to compensate the first target battery capacity through at least one battery capacity compensation value, to obtain the first battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the first compensation module 421H includes: a first compensation sub-module 421H1 configured to obtain a first battery capacity compensation value corresponding to the current compensation process based on the first current value corresponding to the first target time point in the charging working condition data.

In some embodiments of the present application, as shown in FIG. 5 , the first compensation sub-module 421H1 is specifically used to obtain the first battery capacity compensation value through the following formula:

C _{current compensation} = C _C × (Curr _peak -Curr _offset );

In some embodiments of the present application, as shown in FIG. 5 , the first compensation module 421H includes: a second compensation submodule 421H2, configured to obtain a second battery capacity compensation value corresponding to the temperature compensation process based on the target temperature in the charging condition data, wherein the target temperature is the temperature of the second target battery cell in the target power battery when charging in the target power battery ends, wherein the temperature of the second target battery cell is the highest among all the cells of the target power battery.

In some embodiments of the present application, as shown in FIG. 5 , the second compensation sub-module 421H2 is specifically used to obtain the second battery capacity compensation value through the following formula:

C _{temperature compensation} = C _t × (Temp _curr -T');

In some embodiments of the present application, as shown in FIG. 5 , the first compensation module 421H includes: a third compensation sub-module 421H3, configured to obtain a third battery capacity compensation value corresponding to the full charge compensation process based on the second target voltage in the charging condition data, wherein the second target voltage is the voltage of the third target cell in the target power battery when charging in the target power battery ends, wherein the voltage of the third target cell is the highest among all cells of the target power battery.

In some embodiments of the present application, as shown in FIG. 5, the third compensation sub-module 421H3 is specifically used to obtain the third battery capacity compensation value through the following formula:

C _{full compensation} = C _f × (Volt _end -Volt _n );

In some embodiments of the present application, as shown in FIG. 5 , the second compensation module 421I is specifically configured to determine the sum of at least one battery capacity compensation value and the first target battery capacity as the first battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the second determining subunit 422 is specifically configured to execute for each piece of charging condition data: determine the second target battery capacity charged after the target power battery is discharged to the target state of charge based on the charging condition data; obtain the fourth target battery capacity based on the second target battery capacity and the third target battery capacity corresponding to the target state of charge; perform compensation processing on the fourth target battery capacity to obtain the second battery capacity corresponding to the charging condition data.

In some embodiments of the present application, as shown in FIG. 5 , the second determining subunit 422 includes: a fifth determining module 422A, configured to determine a third target time point when charging the target power battery starts and a fourth target time point when charging the target power battery ends, wherein the state of charge at the start of charging the target power battery is the target state of charge; a calculation module 422B, used to perform an ampere-hour integral calculation on the current value between the third target time point and the fourth target time point in the charging condition data to obtain the second target battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the second determination subunit 422 includes: a query module 422C, configured to query the voltage and power curve of the target power battery based on the voltage value corresponding to the preset state of charge, and determine the power value corresponding to the voltage value as the third target battery capacity; a sixth determination module 422D, configured to determine the sum of the second target battery capacity and the third target battery capacity as the fourth target battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the second determination subunit 422 includes: a third compensation module 422E, configured to perform at least one compensation process based on the charging working condition data, to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of temperature compensation processing and full charge compensation processing; a fourth compensation module 422F, configured to compensate the fourth target battery capacity through at least one battery capacity compensation value, to obtain the second battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the third compensation module 422E includes: a fifth compensation submodule 422E1, configured to obtain a second battery capacity compensation value corresponding to the temperature compensation process based on the target temperature in the charging condition data, wherein the target temperature is the temperature of the second target battery cell in the target power battery when charging in the target power battery ends, wherein the temperature of the second target battery cell is the highest among all the cells of the target power battery.

In some embodiments of the present application, as shown in FIG. 5 , the fifth compensation submodule 422E1 is specifically used to obtain the second battery capacity compensation value through the following formula:

C _{temperature compensation} = C _t × (Temp _curr -T');

In some embodiments of the present application, as shown in FIG. 5 , the third compensation module 422E includes: a sixth compensation sub-module 422E2, configured to obtain a third battery capacity compensation value corresponding to the full charge compensation process based on the second target voltage in the charging condition data, wherein the second target voltage is the voltage of the third target cell in the target power battery when charging in the target power battery ends, wherein the voltage of the third target cell is the highest among all cells of the target power battery.

In some embodiments of the present application, as shown in FIG. 5 , the sixth compensation submodule 422E2 is specifically used to obtain the third battery capacity compensation value through the following formula:

C _{full compensation} = C _f × (Volt _end -Volt _n );

In some embodiments of the present application, as shown in FIG. 5 , the fourth compensation module 422F is specifically configured to determine the sum of at least one battery capacity compensation value and the fourth target battery capacity as the second battery capacity.

In some embodiments of the present application, as shown in FIG. 5 , the second determining unit 43 includes: a third determining subunit 431, configured to execute for each first battery capacity: extracting target second battery capacities occurring within a preset time period from each second battery capacity; respectively determining the difference between the first battery capacity and each target second battery capacity; determining the average value of all differences; determining the first battery capacity and the average value as a deviation battery capacity; A determining subunit 433, configured to determine the slope obtained by linear fitting as the target data.

In some embodiments of the present application, as shown in FIG. 5 , the calculation unit 44 includes: a fifth determination subunit 441, configured to determine the target duration between the target time point and the initial time point, wherein the initial time point is the time point when the target power battery is put into use for the first time; a sixth determination subunit 442, used to determine the battery capacity of the target power battery under the target duration based on the slope, the initial capacity of the second battery power battery, and the target duration.

In some embodiments of the present application, as shown in FIG. 5 , the sixth determination subunit 442 is specifically used to determine the battery capacity of the target power battery under the target duration by the following formula:

Cap _predict =k×t+C';

Among them, Cap _predict is the battery capacity of the target power battery under the target duration, k is the slope, t is the target duration, and C′ is the initial capacity of the second battery power battery.

In the power battery capacity calculation device provided in the embodiment of the present application, for detailed explanations of the methods adopted during the operation of each functional module, please refer to the corresponding method detailed explanations of the method embodiment in FIG. 1 , which will not be repeated here.

Further, according to the above embodiment, another embodiment of the present application also provides a controller, the controller includes a processor and a machine-readable storage medium, the machine-readable storage medium stores machine-executable instructions that can be executed by the processor, and the instructions are loaded and executed by the processor: to realize the capacity calculation method of the power battery in Figure 1 .

Further, according to the above-mentioned embodiment, another embodiment of the present application also provides a car machine, which includes: the above-mentioned controller.

Further, according to the above-mentioned embodiment, another embodiment of the present application also provides a vehicle, and the vehicle includes: the above-mentioned vehicle machine.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

It can be understood that related features in the above methods and devices can refer to each other. In addition, "first", "second" and so on in the above embodiments are used to distinguish each embodiment, and do not represent the advantages and disadvantages of each embodiment.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the various embodiments of the application, which should be included in the scope of the claims and description of the application. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

A method for calculating the capacity of a power battery, characterized in that the method comprises:

Obtain multiple pieces of charging condition data of the target power battery;

According to each piece of charging working condition data in the multiple pieces of charging working condition data, at least two battery capacity determining methods are respectively used to obtain the battery capacity corresponding to each battery capacity determining method in the at least two battery capacity determining methods;

Obtaining target data according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods;

Based on the target data, calculate the battery capacity corresponding to the target power battery at a target time point, wherein the target time point is any time point within the entire life cycle of the target power battery.
The method according to claim 1, wherein, according to each piece of charging working condition data in the plurality of pieces of charging working condition data, at least two battery capacity determining methods are respectively used to obtain the battery capacity corresponding to each battery capacity determining method in the at least two battery capacity determining methods, including:

Using the battery capacity determination method based on the anode phase transition feature point of the power battery to determine the battery capacity of each piece of the charging condition data respectively, to obtain the first battery capacity corresponding to each piece of the charging condition data;

A battery capacity determination method based on the state of charge of the power battery is used to determine the battery capacity for each piece of charging condition data, and obtain the second battery capacity corresponding to each piece of charging condition data.
The method according to claim 2, wherein the battery capacity determination method based on the phase transition characteristic point of the anode of the power battery is used to determine the battery capacity of each piece of the charging condition data respectively, and obtain the first battery capacity corresponding to each piece of the charging condition data, including:

For each piece of charging condition data, execute:

Based on the charging voltage of the target power battery in the charging condition data, determine the first target time point corresponding to the anode phase transition characteristic point of the target power battery;

determining a specific first target battery capacity at the end of charging of the target power battery based on the first target time point;

Perform compensation processing on the first target battery capacity to obtain the first battery capacity corresponding to the charging condition data.
The method according to claim 3, wherein, based on the charging voltage of the target power battery in the charging condition data, determining the first target time point corresponding to the anode phase transition characteristic point of the target power battery includes:

Determine a plurality of target charging voltages in the charging condition data, wherein the charging voltage includes an initial voltage, a first target voltage, and at least one charging voltage between the initial voltage and the first target voltage, wherein the initial voltage is the initial voltage when charging the first target battery cell, and the first target voltage is the voltage of the first target battery cell in the target power battery when the charging of the target power battery ends, and the voltage of the first target battery cell is the smallest among all the cells of the target power battery;

generating a differential curve between target charging voltages and time based on the plurality of target charging voltages;

Selecting a target local maximum point from all local maximum points of the differential curve, wherein the peak width of the target local maximum point is the widest among all local maximum points;

The time point corresponding to the target local highest point is determined as the first target time point.
The method according to claim 3, wherein determining the specific first target battery capacity at the end of charging of the target power battery based on the first target time point includes:

Obtaining the first capacity corresponding to the anode phase transition characteristic point of the target power battery;

determining a second capacity charged by the target power battery between the first target time point and a second target time point, the second target time point being the time point when the target power battery ends charging;

The sum of the first capacity and the second capacity is determined as the first target battery capacity.
The method according to claim 5, wherein determining the second capacity of the target power battery charged between the first target time point and the second target time point comprises:

The second capacity is obtained by performing ampere-hour integral calculation on the current value between the first target time point and the second target time point in the charging working condition data.
The method according to claim 3, wherein performing compensation processing on the first target battery capacity to obtain the first battery capacity corresponding to the charging working condition data includes:

Performing at least one compensation process based on the charging condition data to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of current compensation process, temperature compensation process, and full charge compensation process;

Compensating the first target battery capacity by using the at least one battery capacity compensation value to obtain the first battery capacity.
The method according to claim 7, wherein compensating the first target battery capacity through the at least one battery capacity compensation value to obtain the first battery capacity comprises:

The sum of the at least one battery capacity compensation value and the first target battery capacity is determined as the first battery capacity.
The method according to claim 2, wherein the battery capacity determination method based on the state of charge of the power battery is used to determine the battery capacity of each piece of charging condition data, and obtain the second battery capacity corresponding to each piece of charging condition data, including:

For each piece of charging condition data, execute:

determining a second target battery capacity charged after the target power battery is discharged to a target state of charge based on the charging working condition data;

Obtaining a fourth target battery capacity based on the second target battery capacity and a third target battery capacity corresponding to the target state of charge;

Compensation processing is performed on the fourth target battery capacity to obtain a second battery capacity corresponding to the charging working condition data.
The method according to claim 9, wherein determining the second target battery capacity charged after the target power battery is discharged to the target state of charge based on the charging working condition data includes:

Determine a third target time point when charging the target power battery starts and a fourth target time point when charging the target power battery ends, wherein the state of charge of the target power battery when charging starts is the target state of charge;

An ampere-hour integral calculation is performed on the current value between the third target time point and the fourth target time point in the charging working condition data to obtain the second target battery capacity.
The method according to claim 9, wherein the fourth target battery capacity is obtained based on the second target battery capacity and the third target battery capacity corresponding to the target state of charge, comprising:

Based on the voltage value corresponding to the preset state of charge, query the voltage and power curve of the target power battery, and determine the power value corresponding to the voltage value as the third target battery capacity;

The sum of the second target battery capacity and the third target battery capacity is determined as the fourth target battery capacity.
The method according to claim 9, wherein performing compensation processing on the fourth target battery capacity to obtain the second battery capacity corresponding to the charging working condition data includes:

Performing at least one compensation process based on the charging condition data to obtain at least one corresponding battery capacity compensation value, wherein the at least one compensation process includes at least one of temperature compensation process and full charge compensation process;

Compensating the fourth target battery capacity by using the at least one battery capacity compensation value to obtain the second battery capacity.
The method according to claim 12, wherein compensating the fourth target battery capacity through the at least one battery capacity compensation value to obtain the second battery capacity comprises:

The sum of the at least one battery capacity compensation value and the fourth target battery capacity is determined as the second battery capacity.
The method according to claim 7, characterized in that performing current compensation processing based on the charging working condition data to obtain a first battery capacity compensation value corresponding to the current compensation processing, comprising:

Based on the first current value corresponding to the first target time point in the charging working condition data, the first battery capacity compensation value corresponding to the current compensation processing is obtained.
The method according to claim 14, wherein the first battery capacity compensation value corresponding to the current compensation processing is obtained based on the current value corresponding to the target time point in the charging working condition data, comprising:

The first battery capacity compensation value is obtained by the following formula:

C current compensation ＝C C ×(Curr peak -Curr offset )

Wherein, C current compensation is the first battery capacity compensation value, Curr peak is the current value corresponding to the first target time point, C C is the preset current compensation coefficient, and Curr offset is the preset current calibration value.
The method according to claim 7 or 12, characterized in that performing temperature compensation processing based on the charging working condition data to obtain a second battery capacity compensation value corresponding to the temperature compensation processing, comprising:

Based on the target temperature in the charging working condition data, the second battery capacity compensation value corresponding to the temperature compensation processing is obtained, wherein the target temperature is the temperature of a second target battery cell in the target power battery when charging in the target power battery ends, wherein the temperature of the second target battery cell is the highest among all the cells of the target power battery.
The method according to claim 16, wherein the second battery capacity compensation value corresponding to the temperature compensation processing is obtained based on the first target temperature in the charging condition data, comprising:

The second battery capacity compensation value is obtained by the following formula:

C temperature compensation = C t × (Temp curr -T')

Wherein, C temperature compensation is the second battery capacity compensation value, Temp curr is the target temperature, T′ is a preset temperature calibration value, and C t is a preset temperature compensation coefficient.
The method according to claim 7 or 12, wherein the full charge compensation process is performed based on the charging condition data, and the third battery capacity compensation value corresponding to the full charge compensation process is obtained, including:

Based on the second target voltage in the charging working condition data, a third battery capacity compensation value corresponding to the full charge compensation process is obtained, wherein the second target voltage is the voltage of a third target cell in the target power battery when charging in the target power battery ends, wherein the voltage of the third target cell is the highest among all cells in the target power battery.
The method according to claim 18, wherein, based on the target voltage in the charging condition data, obtaining the third battery capacity compensation value corresponding to the full charge compensation process includes:

The third battery capacity compensation value is obtained by the following formula:

C full charge compensation ＝C f ×(Volt end -Volt n )

Wherein, C full charge compensation is the third battery capacity compensation value, Volt end is the second target voltage, Volt n is a preset full charge calibration value, and C f1 is a preset full charge compensation coefficient.
The method according to claim 2, wherein the target data is obtained according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods, including:

Executing for each of the first battery capacities: extracting a target second battery capacity occurring within a preset time period from each of the second battery capacities; respectively determining a difference between the first battery capacity and each of the target second battery capacities; determining an average value of all the differences; determining the first battery capacity and the average value as a deviation battery capacity;

performing a linear fit on the offset battery capacities of all first battery capacities and the time at which each of said first battery capacities occurs;

The slope obtained by linear fitting was determined as the target data.
The method according to claim 20, wherein, based on the target data, calculating the battery capacity corresponding to the target power battery at the target time point includes:

determining a target duration between the target time point and an initial time point, wherein the initial time point is the time point when the target power battery is put into use for the first time;

Based on the slope, the initial capacity of the second battery power battery, and the target duration, the battery capacity of the target power battery under the target duration is determined.
The method according to claim 21, wherein, based on the slope, the initial capacity of the second battery power battery, and the target duration, determining the battery capacity of the target power battery under the target duration includes:

The battery capacity of the target power battery under the target duration is determined by the following formula:

Cap predict =k×t+C'

Wherein, the Cap predict is the battery capacity of the target power battery under the target duration, k is the slope, t is the target duration, and C' is the initial capacity of the second battery power battery.
A capacity calculation device for a power battery, characterized in that the device comprises:

The acquisition unit is used to acquire multiple pieces of charging condition data of the target power battery;

The first determination unit is configured to respectively adopt at least two battery capacity determination methods according to each piece of charging condition data in the plurality of charging condition data, and obtain the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods;

The second determination unit is configured to obtain the target data according to the battery capacity corresponding to each battery capacity determination method in the at least two battery capacity determination methods;

The calculation unit is configured to calculate the battery capacity corresponding to the target power battery at a target time point based on the target data, wherein the target time point is any time point within the entire life cycle of the target power battery.
A controller, characterized in that the controller includes a processor and a machine-readable storage medium, the machine-readable storage medium stores machine-executable instructions that can be executed by the processor, and the instructions are loaded and executed by the processor: to implement the method for calculating the capacity of a power battery according to any one of claims 1-22.
A locomotive, characterized in that the locomotive comprises: the controller according to claim 24.
A vehicle, characterized in that the vehicle comprises: the vehicle machine as claimed in claim 25.