CN117642957A

CN117642957A - Battery charging control method and device, electronic equipment and storage medium

Info

Publication number: CN117642957A
Application number: CN202280013374.XA
Authority: CN
Inventors: 王海将; 黄帅; 倪铭
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2024-03-01
Also published as: WO2023245577A1

Abstract

The application provides a battery charging control method, a battery charging control device, electronic equipment and a storage medium. The battery charge control method includes: controlling the constant voltage charging of the battery according to the fact that the maximum voltage value of the battery cell is larger than or equal to a preset maximum voltage threshold; in the constant voltage charging process, the battery is controlled to be charged in stages at constant voltage according to the magnitude of the request current value. According to the battery charging control method, the power battery charging process is not required to be controlled by acquiring the SOC, lithium precipitation is not caused while the charging current is ensured to be large enough through staged constant-voltage charging, so that charging safety is ensured, and the problem of the technical scheme that the charging current is ensured to be large enough and lithium precipitation is not caused under the condition that the SOC cannot be accurately obtained in the prior art is solved.

Description

Battery charging control method and device, electronic equipment and storage medium

Technical Field

The present disclosure relates to the field of battery technologies, and in particular, to a battery charging control method, a battery charging control device, an electronic device, and a storage medium.

Background

The new energy electric automobile adopts the power battery as a power supply source, and the power battery has the advantages of high energy density, recycling charging, safety, environmental protection and the like, and the market share of the new energy electric automobile is higher and higher. When a new energy electric vehicle is purchased, the charging speed becomes one of the most concerned electric vehicle performance indexes of a plurality of consumers, particularly in the long-distance driving process, when the electric vehicle is charged due to insufficient electric quantity, the charging time can be saved due to the higher charging speed, and the anxiety emotion of a vehicle owner in the charging process is relieved.

In the charging process, as the SOC of the battery is increased, the charging current value is decreased, resulting in a decrease in the charging speed, and when the charging current is too large, the situation of lithium precipitation of the battery is often caused, resulting in a great influence on the charging safety. In the prior art, a technical scheme for controlling the charging process of a power battery under the condition that the SOC cannot be accurately obtained so as to ensure that the charging current is large enough and lithium precipitation cannot be caused at the same time is lacking.

Disclosure of Invention

The embodiment of the application provides a battery charging control method, a battery charging control device, electronic equipment and a storage medium, the power battery charging process is not required to be controlled by acquiring the SOC, and lithium precipitation is not caused while the charging current is ensured to be large enough through staged constant voltage charging, so that charging safety is ensured.

In a first aspect, there is provided a battery charge control method including:

controlling the constant voltage charging of the battery according to the fact that the maximum voltage value of the battery cell is larger than or equal to a preset maximum voltage threshold;

in the constant voltage charging process, the battery is controlled to be charged in a constant voltage stage by stage according to the magnitude of the request current value.

According to the battery charging control method, the battery is controlled to be charged at a constant voltage according to the fact that the maximum voltage value of the battery cell is larger than or equal to the preset maximum voltage threshold, in the constant voltage charging process, the battery is controlled to be charged at a constant voltage stage according to the magnitude of the request current value, the power battery charging process is not required to be controlled by acquiring the SOC, lithium precipitation is not caused while the charging current is ensured to be large enough through the staged constant voltage charging, so that charging safety is ensured, and the problem that in the prior art, a technical scheme that lithium precipitation is not caused while the charging current is ensured to be large enough by controlling the power battery charging process under the condition that the SOC cannot be accurately obtained is solved.

In one implementation manner, in the constant voltage charging process, controlling the battery to perform staged constant voltage charging according to the magnitude of the request current value includes:

Acquiring a preset constant voltage threshold corresponding to a preset current threshold according to the fact that the current request current value is smaller than the preset current threshold corresponding to the current constant voltage charging stage;

and carrying out constant voltage charging at the next stage according to the preset constant voltage threshold value. The charging safety is ensured by the staged constant voltage charging, and the lithium precipitation is not caused while the charging current is ensured to be large enough.

In one implementation manner, the performing constant voltage charging of the next stage according to the preset constant voltage threshold value includes:

and regulating the difference between the real-time maximum voltage value and the preset constant voltage threshold value to be maintained in a preset error interval corresponding to the current constant voltage charging stage according to the real-time voltage value, the real-time current value and the real-time maximum voltage value of the battery cell, so that the voltage accuracy of constant voltage charging is ensured.

In one implementation, the method further comprises:

and in the final constant voltage charging stage, controlling the battery to enter a constant current charging stage according to the fact that the request current value is smaller than or equal to a preset minimum current threshold value, wherein the preset minimum current threshold value is smaller than or equal to the minimum value in the lower limit value of the at least one preset current value interval. The constant current charging phase ensures that the charging current value is kept at a higher level and a higher charging speed is ensured.

In one implementation, the method further comprises:

and in the constant current charging stage, stopping charging when the voltage of the battery cell is greater than or equal to the full charge cut-off voltage for a preset period of time, so that the battery is ensured to be charged with enough electric quantity.

In one implementation, the controlling the battery to enter a constant current charging phase includes: and controlling constant-current charging of the battery according to the preset threshold value, so that the charging current value can be ensured to be kept at a higher level, and a higher charging speed can be ensured.

In one implementation, the controlling constant current charging the battery according to the preset threshold includes:

and controlling the difference value between the actual charging current value and the preset current threshold value to be kept in a second preset difference value interval, and charging the battery, so that the charging current value can be ensured to be kept at a higher level, and a higher charging speed can be ensured.

In one implementation, before the maximum voltage value of the battery cell according to the battery reaches a first preset condition, the method further includes:

acquiring an adaptive charging current value according to the real-time temperature and the real-time voltage or the real-time SOC of the battery;

And carrying out constant-current charging on the battery according to the adaptive charging current value. By controlling the battery to be charged according to the acquired adaptive charging current value, charging safety and a larger charging speed can be ensured.

In one implementation, the obtaining the adapted charging current value according to the real-time temperature and the real-time voltage or the real-time SOC of the battery includes:

and according to the real-time SOC or the real-time voltage and the real-time temperature, acquiring a corresponding adaptive charging current value by looking up a charging window table. The battery is charged by controlling the adaptive charging current value obtained according to the table lookup, so that the charging safety and the larger charging speed in the constant-current charging stage can be ensured.

In one implementation, the constant current charging of the battery according to the adapted charging current value includes:

and controlling the difference value between the actual charging current value and the adaptive charging current value to be kept within a first preset difference value interval, and carrying out constant current charging on the battery. The difference value between the actual charging current value and the adaptive charging current value is controlled to be kept in the first preset interval to charge the battery, so that the charging safety and the larger charging speed during constant-current charging can be ensured.

In a second aspect, there is provided a battery charge control device including:

the first control module is used for controlling constant voltage charging of the battery according to the fact that the maximum voltage value of the battery cell is larger than or equal to a preset maximum voltage threshold;

and the second control module is used for controlling the battery to be subjected to staged constant voltage charging according to the magnitude of the request current value in the constant voltage charging process.

According to the battery charging control device, the battery is controlled to be charged at a constant voltage according to the fact that the maximum voltage value of the battery cell is larger than or equal to the preset maximum voltage threshold, in the constant voltage charging process, the battery is controlled to be charged at a constant voltage stage by stage according to the magnitude of the request current value, the power battery charging process is not required to be controlled by acquiring the SOC, lithium precipitation is not caused when the charging current is ensured to be large enough through the staged constant voltage charging, and therefore charging safety is ensured, and the problem that in the prior art, the technical scheme that lithium precipitation is not caused when the charging current is ensured to be large enough through controlling the power battery charging process under the condition that the SOC cannot be accurately obtained is solved.

In a third aspect, there is provided an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the battery charge control method of any one of the above. The electronic equipment can achieve the same beneficial technical effects as the battery charging control method.

In a fourth aspect, there is provided a computer-readable storage medium having stored thereon a computer program that is executed by a processor to implement the battery charge control method of any one of the above. The computer readable storage medium can achieve the same advantageous technical effects as the battery charge control method described above.

In a fifth aspect, there is provided a power plant comprising a power battery for supplying electric energy and the electronic device of the third aspect for performing the battery charge control method of any one of the above on the power battery. The power device can achieve the same beneficial technical effects as the battery charging control method.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a graph of voltage during charging of a lithium iron phosphate material battery.

Fig. 2 is a flowchart of a battery charge control method according to an embodiment of the present application.

Fig. 3 is a functional schematic of a PID control algorithm.

FIG. 4 is a flow chart of adjusting a real-time charging voltage value as a feedback value for a negative feedback PID adjustment according to some embodiments of the application.

Fig. 5 is a flow chart of controlling constant current charging of a battery in some embodiments of the present application.

Fig. 6 is a block diagram of a battery charge control device according to another embodiment of the present application.

Fig. 7 is a block diagram of an electronic device according to another embodiment of the present application.

Fig. 8 is a schematic diagram of a computer readable storage medium according to another embodiment of the present application.

Fig. 9 is a block diagram of a power plant according to another embodiment of the present application.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the present application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like indicate an orientation or positional relationship merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

The directional terms appearing in the following description are all directions shown in the drawings and do not limit the specific structure of the present application. In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present application can be understood as appropriate by one of ordinary skill in the art.

Along with the development of science and technology and the progress of the era, the new energy automobile has the advantages of good environmental protection performance, low noise, low use cost and the like, can effectively promote energy conservation and emission reduction, can meet environmental protection requirements, is beneficial to sustainable development of social economy, and has higher market share. The new energy automobile uses a power battery as a power source, wherein a lithium ion battery is the most commonly used power battery.

Currently, an electric automobile generally selects a lithium ion battery system as a power source, and since the lithium ion battery is a chemical system product, the charging capability of lithium ions is limited by multi-step chemical reactions inside the battery. The inventors of the present application found that, when electrons move from the positive electrode to the negative electrode outside the battery during charging, lithium ions in the solid phase of the positive electrode diffuse from the bulk phase to the surface in synchronization with the movement of the electrons, and charge transfer occurs at the solid/liquid interface; reaching the surface of the negative electrode through liquid phase mass transfer, and passing through a solid-liquid interface film (Solid Eletrolyte Interface-SEI) on the interface of the negative electrode to enter the surface layer of graphite, and then diffusing into the bulk lattice of the negative electrode (usually graphite) with an electronic system waiting in a conductive network of the negative electrode; since graphite has lamellar channels, when lithium ions intercalate into the channels to form carbon lithium compounds with carbon, liC is formed _x (x=1 to 6) such graphite intercalation compounds, followed by solid phase transport in the graphite; as the intercalation amount of lithium in graphite increases, the value of x increases from x=0 to x=1, so that lithium intercalation compounds of different phases such as 1, 4, 3, 2L, 2 and 1 are gradually generated; n appears on the charge-discharge curve corresponding to the phase transition with the lithium intercalation chemical ₁ V，N ₂ V，N ₃ V(vs Li ⁺ A potential plateau appears near Li); when the lithium ion intercalation amount is more than 50%, the lithium ion batteryThe potential of the graphite cathode will appear from N ₂ V gradually goes to N ₃ V decreasing transition process corresponding to lithium ion intercalation amount from LiC ₁₂ Towards LiC ₆ And (5) transition.

The lithium is separated from the negative electrode, which is the most main cause of safety accidents of the lithium ion battery, and the lithium is separated from the negative electrode of the lithium ion battery, wherein the excessive charging current is one of the main causes of the lithium separation from the negative electrode. Lithium precipitation from the negative electrode can result in reduced thermal stability of the battery negative electrode, and meanwhile, formed lithium dendrites can puncture the separator, so that the positive electrode and the negative electrode are short-circuited, and battery safety accidents are caused.

In the charging process of the electric automobile, how to ensure that the charging current is large enough and meanwhile, lithium is not separated out during charging is two aspects of comprehensive balance. In addition, the inventors have found that the higher the State Of Charge (State Of Charge-SOC) is during charging, the more the lithium intercalation amount is, and the smaller the charging capability current Of the battery cell is. Therefore, the charging capacity of the low-end SOC area is higher than that of the high-end SOC area at the same ambient temperature; with the increase of the SOC state, the charging capability of the battery cell gradually decreases.

Therefore, in the charging process of the electric automobile, the charging request current is generally used as a reference calculation basis according to the SOC state value of the lithium ion battery or the single battery cell voltage value in the charging process; however, the battery core of the lithium iron phosphate system is subjected to two-phase reaction in the charge and discharge process due to the chemical property of the lithium iron phosphate material, and according to the Gibbs phase law, the degree of freedom = substance component number-phase number + external factors, the voltage value of the lithium iron phosphate material in the charge and discharge process can be calculated and known to be unchanged, and a voltage platform area exists; so that it has a flat charge-discharge plateau around 3.4V; due to the problem of a voltage platform area of the lithium iron phosphate battery core, the SOC calculation of the battery core is inaccurate, and the requirement on the accuracy of the SOC value during charging cannot be ensured.

The lithium iron phosphate material battery has larger charging multiplying power in the low-end SOC section and small charging multiplying power in the high-end SOC section, so that in the charging process, the charging dynamic voltage of the lithium iron phosphate material battery in the middle-end and low-end SOC section is higher than the dynamic voltage of the high-end SOC section due to polarization of a lithium ion battery core, as shown in fig. 1. When the SOC is not calculated, how to ensure the safe and rapid charging of the battery core of the lithium iron phosphate material battery is a technical problem which needs to be solved by a Battery Management System (BMS).

The inventor also finds that constant voltage charging is an effective charging mode for balancing charging time and charging safety, and when the battery enters a constant voltage charging stage, the potential is gradually increased as the positive electrode of the battery is continuously separated from lithium ions; while the potential of the negative electrode gradually decreases along with the continuous intercalation of lithium ions; when the constant voltage charge is carried out, the potential of the positive electrode is continuously increased, and the current is gradually reduced, so that the potential of the negative electrode is slowly increased; therefore, when the constant voltage charging process is carried out, the potential of the negative electrode is not as low as 0V, and the lithium ion battery is not leached to cause safety accidents in the constant voltage charging process.

For convenience of description, an application of the power battery to a new energy vehicle (power vehicle) will be explained below as an example. The battery in the embodiment of the application may be a battery cell unit, a battery module or a battery pack, which is not limited herein. From the application scene, the battery can be applied to power devices such as automobiles, ships and the like. For example, the device can be applied to a power automobile to supply power for a motor of the power automobile and serve as a power source of the electric automobile. The battery can also supply power to other electrical devices in the electric automobile, such as in-car air conditioners, car players and the like.

In order to solve the technical problem that lithium precipitation cannot be ensured while ensuring that the charging current is sufficiently large in the charging process when SOC calculation is inaccurate, according to the battery charging control method, constant voltage charging is controlled to be performed on the battery according to the fact that the maximum voltage value of a battery cell is greater than or equal to a preset maximum voltage threshold value, in the constant voltage charging process, the battery is controlled to be subjected to staged constant voltage charging according to the magnitude of a request current value, the power battery charging process is not required to be controlled by acquiring the SOC, lithium precipitation cannot be caused while ensuring that the charging current is sufficiently large through staged constant voltage charging, so that charging safety is ensured, charging safety is ensured while ensuring that the charging current is sufficiently large and lithium precipitation cannot be caused through controlling the power battery charging process when the SOC cannot be accurately obtained, and safe and rapid charging of the battery is realized.

As shown in fig. 2, an embodiment of the present application provides a battery charge control method including steps S10 to S20.

The execution subject of the battery charge control method may be a battery management system BMS. For example, when the vehicle is charged at high voltage, the charging gun is inserted for charging, the charging pile and the vehicle complete information interaction, the vehicle and a Battery Management System (BMS) complete internal communication, the Battery Management System (BMS) calculates acceptable charging capacity of the battery cell according to current voltage, temperature, SOC and other information and sends the acceptable charging capacity to the vehicle system and the charging pile, after the charging pile receives charging request current related information sent by the BMS, the charging pile timely responds and outputs related request charging current, and the battery management system obtains a maximum output current value of the charging pile according to the interaction information of the charging pile, and charges according to the maximum output current value of the charging pile. The battery comprises at least one cell, which may be a cell of lithium iron phosphate material.

And S10, controlling the constant voltage charge of the battery according to the fact that the maximum voltage value of the battery cell is larger than or equal to a preset maximum voltage threshold.

And when the maximum voltage value of the battery cell unit of the battery is greater than or equal to a preset maximum voltage threshold value, controlling the battery to enter a constant voltage charging stage. Specifically, the maximum voltage value of the battery cell in the charging process is detected in real time, and when the maximum voltage value of the battery cell is greater than or equal to a preset maximum voltage threshold volt_max, the battery is controlled to enter a constant voltage charging stage. The preset maximum voltage threshold may be, for example, 3.0V, 3.2V or 3.5V, and may be specifically set according to actual needs.

S20, in the constant voltage charging process, controlling the battery to be subjected to constant voltage charging in stages according to the magnitude of the request current value. The charging safety is ensured by the staged constant voltage charging, and the lithium precipitation is not caused while the charging current is ensured to be large enough.

In some embodiments, according to the current request current value being smaller than a preset current threshold corresponding to the current constant voltage charging stage, a preset constant voltage threshold corresponding to the preset current threshold is obtained; and according to the preset constant voltage threshold value, constant voltage charging in the next stage is carried out.

For example, the current request current value is 0.7A, the preset current threshold corresponding to the current constant voltage charging stage is 0.8A, and since the current request current value is 0.7A and is smaller than the preset current threshold corresponding to the current constant voltage charging stage by 0.8A, the preset constant voltage threshold corresponding to the preset current threshold 0.8A is 3.5V, constant voltage charging in the next stage is performed according to the preset constant voltage threshold 3.5V.

Illustratively, performing the constant voltage charging of the next stage according to the preset constant voltage threshold value may include: according to the real-time voltage value, the real-time current value and the real-time maximum voltage value of the battery cell single body, the difference between the real-time maximum voltage value and the preset constant voltage threshold is regulated to be maintained in a preset error interval corresponding to the current constant voltage charging stage, and the voltage accuracy of constant voltage charging is ensured.

For example, when constant voltage charging is performed according to a preset constant voltage threshold value of 3.5V, a closed loop algorithm such as PID algorithm is adopted to adjust the difference between the real time maximum voltage value and the preset constant voltage threshold value to be within a preset error interval [ -0.15,0.15] corresponding to the current constant voltage charging stage, namely, the real time maximum voltage value of-0.15V is ensured to be less than or equal to-3.5V is ensured to be less than or equal to 0.15V, so that the interval to which the real time maximum voltage value belongs is ensured to be [3.35,3.65] V.

In some embodiments, step S20 may include: and regulating to maintain the maximum voltage value of the battery in a corresponding preset voltage value interval according to the request current value and at least one preset current value interval of the current management system.

Specifically, the adjustment mode may be a closed-loop algorithm adjustment mode, such as a PID adjustment algorithm. As shown in fig. 3, the PID control algorithm is a control algorithm combining three operation links of proportional, integral and differential, that is, according to the input deviation value, the PID control algorithm performs operation according to the functional relationship of proportional, integral and differential, and the operation result is used to control output.

As shown in fig. 4, in some embodiments, step S20 may include steps S201 to S203:

s201, determining a preset current value interval to which the request current value belongs, and a corresponding preset constant voltage threshold value and a corresponding preset error interval corresponding to the preset current value interval to which the request current value belongs.

Each preset current value interval in the at least one preset current value interval corresponds to a preset constant voltage threshold value and a preset error interval respectively. As shown in table 1, the preset constant voltage threshold and the preset error interval are set for a plurality of preset current value intervals.

TABLE 1

Presetting a current value interval: a is that	Presetting a constant voltage threshold value: v (V)	Presetting an error interval: v (V)
(1.0,1.2]	4.0	[-0.15,0.15]
(0.6,0.9]	3.5	[-0.15,0.15]
(0.3,0.6]	3.0	[-0.10,0.10]
……	……	……
(0.1,0.2]	1.0	[-0.05,0.05]
……	……	……

For example, if the current request current value is 0.7A, it can be determined from table 1 that the interval to which 0.7A belongs is (0.6,0.9), the corresponding preset constant voltage threshold is 3.5V, and the corresponding preset error interval is [ -0.15,0.15].

S202, adjusting to enable the difference between the real-time maximum voltage value and the corresponding preset constant voltage threshold value to be maintained in the corresponding preset error interval according to the real-time voltage value, the real-time current value and the real-time maximum voltage value of the battery cell.

Specifically, the adjustment mode can be adjusted by adopting a PID adjustment algorithm. In the constant voltage charging stage, the battery management system BMS performs closed-loop algorithm adjustment according to the real-time voltage value, the real-time maximum voltage value and the real-time current value acquired in real time by the battery cell unit, so that the real-time maximum voltage value is maintained to be kept at a corresponding preset constant voltage threshold value +/-deviation threshold value. The closed loop algorithm may be, for example, a PID tuning algorithm.

And S203, updating the request current value when the request current value changes to belong to another preset current value interval, and turning to the preset current value interval to which the request current value belongs to be determined and circularly executing until the request current value is smaller than or equal to a preset threshold value.

Specifically, in the Constant voltage charging stage, the actual current value is adaptively adjusted to continuously decrease according to the dynamic performance of the battery cell, when the corresponding request current value is smaller than the preset current threshold value i_req_numone, the corresponding Constant voltage threshold value v_constant_one is found out according to the preset current threshold value i_req_numone, and the battery management system BMS performs closed-loop algorithm (for example, PID algorithm) adjustment according to the latest Constant voltage threshold value by combining the real-time acquired maximum voltage value and the real-time acquired current value, so as to maintain the maximum voltage value of the battery to be kept at the Constant voltage threshold value v_constant_one±deviation threshold value; and in a new constant voltage threshold constant voltage charging stage, when the actual current is continuously reduced according to the dynamic performance self-adaptive regulation of the battery core, and when the request current in the constant voltage stage is smaller than a certain current threshold value, a new constant voltage threshold value is reconfirmed, and constant voltage charging is carried out. The actual current value is preset in a current value interval and a corresponding preset constant voltage threshold value and a corresponding preset error interval in the descending process, and the actual current value can be tested and calibrated according to different electric core material systems.

Corresponding to the example shown in table 1, the preset threshold value is 0.1A. And stopping updating the request current value when the request current value is less than or equal to 0.1A.

For example, taking table 1 as an example, if the request current value is 0.7A, it can be determined from table 1 that the interval to which 0.7A belongs is (0.6,0.9), the corresponding preset constant voltage threshold is 3.5V, and the corresponding preset error interval is [ -0.15,0.15], when the request current value is reduced to 0.5A, it can be determined from table 1 that the interval to which 0.5A belongs is (0.3, 0.6), the corresponding preset constant voltage threshold is 3.0V, and the corresponding preset error interval is [ -0.10,0.10], that is, the loop is turned to S201 until the request current value is less than or equal to the preset threshold 0.1A.

In some implementations, the method of the present embodiment may further include:

s30, in the final constant voltage charging stage, controlling the battery to enter a constant current charging stage according to the fact that the request current value is smaller than or equal to a preset minimum current threshold value, wherein the preset minimum current threshold value is smaller than or equal to the minimum value in each lower limit value of at least one preset current value interval. The constant current charging phase ensures that the charging current value is kept at a higher level and a higher charging speed is ensured.

The last constant voltage charging stage may be the last n constant voltage charging stages, where n is a positive integer, for example, the last constant voltage charging stage, the last two constant voltage charging stages, or the last three constant voltage charging stages may be the last constant voltage charging stage, and the value of n may be selected according to practical application requirements, that is, the last constant voltage charging stage is a relatively later stage with respect to the whole charging stage.

As shown in table 1, the minimum value of the lower limit values of the preset current value intervals is 0.1A, and the preset threshold value in this example is 0.1A. And when the request current value is less than or equal to 0.1A, controlling the battery to enter a constant current charging stage.

In some embodiments, controlling the battery to enter a constant current charging phase may include: and the constant-current charging is controlled to be carried out on the battery according to a preset threshold value, so that the charging current value can be ensured to be kept at a higher level, and the higher charging speed can be ensured.

Illustratively, controlling constant current charging of the battery according to a preset threshold may include: the difference value between the actual charging current value and the preset current threshold value is controlled to be kept in a second preset difference value interval, and the battery is charged, so that the charging current value can be ensured to be kept at a higher level, and the higher charging speed can be ensured.

For example, the battery management system BMS may send a request current value to the charging pile, and the charging pile receives charging request current related information sent by the BMS and then timely responds to and outputs the related request charging current, so as to control the difference between the actual charging current value and the preset current threshold to be kept within a second preset difference interval, and charge the battery. The BMS can compare the difference value between the actual charging current value detected in real time and the preset current threshold value with a second preset difference value interval, and when the difference value exceeds the upper limit value of the second preset difference value interval, the BMS sends an instruction for reducing the charging current value to the charging pile so as to reduce the charging current value output by the charging pile until the difference value is positioned in the second preset difference value interval; when the difference is smaller than the lower limit value of the second preset difference interval, the BMS sends an instruction for improving the charging current value to the charging pile so as to enable the charging current value output by the charging pile to be increased until the difference is located in the second preset difference interval.

In some embodiments, the method further comprises:

and S40, in the constant current charging stage, stopping charging when the voltage of the battery cell reaches a preset stopping condition.

Specifically, stopping the charging when the voltage of the battery cell reaches a preset stop condition may include: and stopping charging when the voltage of the battery cell is greater than or equal to the full charge cut-off voltage for a preset period of time, so that the battery is ensured to be charged with enough electric quantity.

In some embodiments, before the battery is controlled to enter the constant voltage charging phase according to the first preset condition being reached by the maximum voltage value of the battery cell, the method further comprises:

s00, controlling constant current charging of the battery.

Specifically, step S00 may include:

s001, acquiring an adaptive charging current value according to the real-time temperature and the real-time voltage or the real-time SOC of the battery.

Illustratively, step S001 may include: and according to the real-time SOC or the real-time voltage and the real-time temperature, acquiring a corresponding adaptive charging current value by looking up a charging window table. The battery is charged by controlling the adaptive charging current value obtained according to the table lookup, so that the charging safety and the larger charging speed in the pre-charging stage can be ensured.

Specifically, the SOC value or the voltage value of the battery cell can be accurately identified, the temperature of the battery cell can be combined, the corresponding adaptive charging current value can be obtained by accurately identifying the maximum SOC, the minimum SOC or the real-time voltage value according to the battery cell, and the maximum temperature and the minimum temperature of the battery cell can be combined, and the adaptive charging current value can be obtained by looking up the charging window table.

And S002, constant-current charging is carried out on the battery according to the adaptive charging current value.

The battery is subjected to constant current charging according to the obtained adaptive charging current value, so that a large charging speed and charging safety can be ensured.

Illustratively, step S002 may include: and controlling the difference value between the actual charging current value and the adaptive charging current value to be kept within a first preset difference value interval, and charging the battery. The difference value between the actual charging current value and the adaptive charging current value is controlled to be kept within the first preset difference value interval to charge the battery, so that the charging safety and the larger charging speed in the pre-charging stage can be ensured.

According to the battery charging control method, the battery is controlled to be charged at a constant voltage according to the fact that the maximum voltage value of the battery cell is larger than or equal to the preset maximum voltage threshold, in the constant voltage charging process, the battery is controlled to be charged at a constant voltage stage according to the magnitude of the request current value, the power battery charging process is not required to be controlled by acquiring the SOC, lithium precipitation is not caused while the charging current is ensured to be large enough through the staged constant voltage charging, and therefore charging safety is ensured, and the problem that in the prior art, a technical scheme that lithium precipitation is not caused while the charging current is ensured to be large enough through controlling the power battery charging process under the condition that the SOC cannot be obtained accurately is solved.

As shown in fig. 6, another embodiment of the present application provides a battery charge control device, including:

and the second control module is used for controlling the battery to be charged in a constant voltage stage by stage according to the magnitude of the request current value in the constant voltage charging process.

In some embodiments, the second control module may include:

the first submodule is used for acquiring a preset constant voltage threshold corresponding to the preset current threshold according to the fact that the current value of the current request is smaller than the preset current threshold corresponding to the current constant voltage charging stage;

and the second sub-module is used for carrying out constant voltage charging at the next stage according to the preset constant voltage threshold value.

In some embodiments, the constant voltage charging performed by the second sub-module according to the preset constant voltage threshold value, includes:

and regulating to maintain the difference between the real-time maximum voltage value and a preset constant voltage threshold value within a preset error interval corresponding to the current constant voltage charging stage according to the real-time voltage value, the real-time current value and the real-time maximum voltage value of the battery cell.

In some embodiments, the apparatus further comprises:

and the third control module is used for controlling the battery to enter the constant-current charging stage according to the fact that the request current value is smaller than or equal to a preset minimum current threshold value in the last constant-voltage charging stage, and the preset minimum current threshold value is smaller than or equal to the minimum value in each lower limit value of at least one preset current value interval.

In some embodiments, the apparatus further comprises:

and the charging stopping module is used for stopping charging when the voltage of the battery cell monomer is greater than or equal to the full charge cut-off voltage for a preset period of time in the constant current charging stage.

In some embodiments, controlling the battery to enter a constant current charging phase includes: and controlling constant current charging of the battery according to a preset threshold value.

In some embodiments, controlling constant current charging of the battery according to a preset threshold includes:

and controlling the difference value between the actual charging current value and the preset current threshold value to be kept in a second preset difference value interval, and charging the battery.

In some embodiments, the apparatus further comprises a pre-charging module for controlling the pre-charging of the battery before the battery is controlled to enter the constant voltage charging phase according to the maximum voltage value of the battery cell reaching a first preset condition.

Specifically, the precharge module may include:

the adaptive charging current value acquisition unit is used for acquiring an adaptive charging current value according to the real-time temperature and the real-time voltage or the real-time SOC of the battery;

and the constant-current charging unit is used for carrying out constant-current charging on the battery according to the adaptive charging current value.

In some embodiments, the adaptive charging current value obtaining unit is further specifically configured to obtain, according to the real-time SOC or the real-time voltage, a corresponding adaptive charging current value by looking up a charging window table in combination with the real-time temperature.

In some embodiments, constant current charging of the battery according to the adapted charge current value comprises: and controlling the difference value between the actual charging current value and the adaptive charging current value to be kept within a first preset difference value interval, and carrying out constant-current charging on the battery.

According to the battery charging control device, the battery can be subjected to constant voltage charging according to the fact that the maximum voltage value of the battery cell is larger than or equal to the preset maximum voltage threshold, in the constant voltage charging process, the battery is controlled to be subjected to staged constant voltage charging according to the magnitude of the request current value, the power battery charging process is not required to be controlled through obtaining the SOC, lithium precipitation can not be caused when the charging current is ensured to be large enough through staged constant voltage charging, so that charging safety is ensured, and the problem that in the prior art, the technical scheme that lithium precipitation cannot be caused when the charging current is ensured to be large enough through controlling the power battery charging process under the condition that the SOC cannot be accurately obtained is solved.

Another embodiment of the present application provides an electronic device including a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor executing the computer program to implement the battery charge control method of any of the above embodiments. The electronic device may be, for example, a battery management system BMS or the like.

As shown in fig. 7, the electronic device 10 may include: processor 100, memory 101, bus 102 and communication interface 103, processor 100, communication interface 103 and memory 101 being connected by bus 102; the memory 101 has stored therein a computer program executable on the processor 100, which when executed by the processor 100 performs the method provided by any of the embodiments described herein.

The memory 101 may include a high-speed random access memory (RAM: random Access Memory), and may further include a non-volatile memory (non-volatile memory), such as at least one disk memory. The communication connection between the system network element and the at least one other network element is implemented via at least one communication interface 103 (which may be wired or wireless), the internet, a wide area network, a local network, a metropolitan area network, etc. may be used.

Bus 102 may be an ISA bus, a PCI bus, an EISA bus, or the like. The buses may be divided into address buses, data buses, control buses, etc. The memory 101 is configured to store a program, and the processor 100 executes the program after receiving an execution instruction, and the method disclosed in any of the foregoing embodiments of the present application may be applied to the processor 100 or implemented by the processor 100.

The processor 100 may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in the processor 100 or by instructions in the form of software. The processor 100 may be a general-purpose processor, and may include a central processing unit (Central Processing Unit, CPU for short), a network processor (Network Processor, NP for short), and the like; but may also be a Digital Signal Processor (DSP), application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The disclosed methods, steps, and logic blocks in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in the memory 101, and the processor 100 reads the information in the memory 101 and, in combination with its hardware, performs the steps of the method described above.

The electronic device provided by the embodiment of the application and the method provided by the embodiment of the application are the same in the invention conception, and have the same beneficial effects as the method adopted, operated or realized by the electronic device.

Another embodiment of the present application provides a computer-readable storage medium having stored thereon a computer program that is executed by a processor to implement the battery charge control method of any of the above embodiments.

The present application further provides a computer readable storage medium corresponding to the method provided in the foregoing embodiments, and referring to fig. 8, the computer readable storage medium is shown as an optical disc 20, on which a computer program (i.e. a program product) is stored, where the computer program, when executed by a processor, performs the method provided in any of the foregoing embodiments.

It should be noted that examples of the computer readable storage medium may also include, but are not limited to, a phase change memory (PRAM), a Static Random Access Memory (SRAM), a Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), a Read Only Memory (ROM), an Electrically Erasable Programmable Read Only Memory (EEPROM), a flash memory, or other optical or magnetic storage medium, which will not be described in detail herein.

The computer readable storage medium provided by the above-described embodiments of the present application has the same advantageous effects as the method adopted, operated or implemented by the application program stored therein, for the same inventive concept as the method provided by the embodiments of the present application.

As shown in fig. 9, another embodiment of the present application provides a power device, including a power battery and an electronic device according to any one of the foregoing embodiments, where the power battery is configured to provide electric energy, and the electronic device is configured to perform the battery charging control method according to any one of the foregoing embodiments on the power battery. The power device may be, for example, an electric vehicle such as an electric vehicle, or may be another electric power device.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions should be covered in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A battery charge control method, characterized by comprising:

controlling the constant voltage charging of the battery according to the fact that the maximum voltage value of the battery cell is larger than or equal to a preset maximum voltage threshold;

in the constant voltage charging process, the battery is controlled to be charged in a constant voltage stage by stage according to the magnitude of the request current value.
The method of claim 1, wherein controlling the step-wise constant voltage charging of the battery according to the magnitude of the requested current value during the constant voltage charging includes:

acquiring a preset constant voltage threshold corresponding to a preset current threshold according to the fact that the current request current value is smaller than the preset current threshold corresponding to the current constant voltage charging stage;

and carrying out constant voltage charging at the next stage according to the preset constant voltage threshold value.
The method according to claim 2, wherein the performing constant voltage charging of the next stage according to the preset constant voltage threshold value includes:

and regulating to maintain the difference between the real-time maximum voltage value and the preset constant voltage threshold value within a preset error interval corresponding to the current constant voltage charging stage according to the real-time voltage value, the real-time current value and the real-time maximum voltage value of the battery cell.
The method according to claim 1, wherein the method further comprises:

and in the final constant voltage charging stage, controlling the battery to enter a constant current charging stage according to the fact that the request current value is smaller than or equal to a preset minimum current threshold value, wherein the preset minimum current threshold value is smaller than or equal to the minimum value in the lower limit value of the at least one preset current value interval.
The method according to claim 4, wherein the method further comprises:

and in the constant current charging stage, stopping charging when the voltage of the battery cell is greater than or equal to the full charge cut-off voltage for a preset period of time.
The method of claim 4, wherein said controlling the battery to enter a constant current charging phase comprises: and controlling constant current charging of the battery according to the preset threshold value.
The method of claim 6, wherein the controlling constant current charging the battery according to the preset threshold comprises:

and controlling the difference value between the actual charging current value and the preset current threshold value to be kept in a second preset difference value interval, and charging the battery.
The method of claim 1, wherein the step of determining the position of the substrate comprises,

Before the maximum voltage value of the battery cell according to the battery reaches a first preset condition and the battery is controlled to enter a constant voltage charging stage, the method further comprises:

acquiring an adaptive charging current value according to the real-time temperature and the real-time voltage or the real-time SOC of the battery;

and carrying out constant-current charging on the battery according to the adaptive charging current value.
The method of claim 8, wherein the obtaining an adapted charge current value based on the real-time temperature and the real-time voltage or the real-time SOC of the battery comprises:

and according to the real-time SOC or the real-time voltage and the real-time temperature, acquiring a corresponding adaptive charging current value by looking up a charging window table.
The method of claim 8, wherein the constant current charging the battery according to the adapted charge current value comprises:

and controlling the difference value between the actual charging current value and the adaptive charging current value to be kept within a first preset difference value interval, and carrying out constant current charging on the battery.
A battery charge control device, characterized by comprising:

the first control module is used for controlling constant voltage charging of the battery according to the fact that the maximum voltage value of the battery cell is larger than or equal to a preset maximum voltage threshold;

And the second control module is used for controlling the battery to be subjected to staged constant voltage charging according to the magnitude of the request current value in the constant voltage charging process.
An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the battery charge control method of any one of claims 1-10.
A computer-readable storage medium having stored thereon a computer program, characterized in that the program is executed by a processor to implement the battery charge control method according to any one of claims 1 to 10.
A power plant comprising a power battery for supplying electric energy and an electronic device according to claim 13 for performing the battery charge control method according to any one of claims 1-10 on the power battery.