WO2023245577A1

WO2023245577A1 - Battery charging control method and apparatus, electronic device, and storage medium

Info

Publication number: WO2023245577A1
Application number: PCT/CN2022/100907
Authority: WO
Inventors: 王海将; 黄帅; 倪铭
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2023-12-28
Also published as: CN117642957A

Abstract

Provided are a battery charging control method and apparatus, an electronic device, and a storage medium. The battery charging control method comprises: according to a maximum voltage value of a battery cell of a battery being greater than or equal to a preset maximum voltage threshold, controlling to perform constant-voltage charging on the battery (S10); and in the constant-voltage charging process, according to the magnitude of a requested current value, controlling to perform staged constant-voltage charging on the battery (S20). According to the provided battery charging control method, a power battery charging process does not need to be controlled by obtaining an SOC, and by means of the staged constant-voltage charging, lithium precipitation cannot be caused while a charging current is ensured to be large enough, thereby ensuring the charging safety, and solving the problem in the prior art for when the SOC cannot be accurately obtained, lacking of the technical solution that the power battery charging process is controlled such that the lithium precipitation cannot be caused while ensuring that the charging current is large enough.

Description

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

Technical field

The present application relates to the field of battery technology, and in particular, to a battery charging control method, a battery charging control device, electronic equipment and a storage medium.

Background technique

New energy electric vehicles use power batteries as power sources. Power batteries have the advantages of high energy density, rechargeability, safety and environmental protection. The market share of new energy electric vehicles is increasing. When purchasing new energy electric vehicles, charging speed has become one of the performance indicators of electric vehicles that many consumers are most concerned about. Especially during long-distance driving, when the electric vehicle has insufficient power for charging, a higher charging speed can save charging time. , to relieve car owners’ anxiety during the charging process.

During the charging process, as the battery's state of charge (SOC) increases, the charging current value will decrease, resulting in a decrease in charging speed. When the charging current is too large, it will often lead to lithium precipitation in the battery, causing the charging safety to be greatly affected. . The existing technology lacks a technical solution to control the charging process of the power battery to ensure that the charging current is large enough without causing lithium deposition when the SOC cannot be accurately obtained.

Contents of the invention

Embodiments of the present application provide a battery charging control method, battery charging control device, electronic equipment and storage media. There is no need to obtain SOC to control the charging process of the power battery. Through staged constant voltage charging, it is possible to ensure sufficient charging current. It is large and will not cause lithium deposition, thus ensuring charging safety.

In the first aspect, a battery charging control method is provided, including:

According to the maximum voltage value of the cell cell of the battery being greater than or equal to the preset maximum voltage threshold, control the constant voltage charging of the battery;

During the constant voltage charging process, the battery is controlled to be charged at constant voltage in stages according to the requested current value.

The battery charging control method provided by the embodiment of the present application controls the constant voltage charging of the battery according to the maximum voltage value of the cell cell of the battery is greater than or equal to the preset maximum voltage threshold. During the constant voltage charging process, according to the requested current value size, controlling the staged constant voltage charging of the battery. There is no need to obtain SOC to control the charging process of the power battery. Through staged constant voltage charging, it is achieved to ensure that the charging current is large enough without causing lithium precipitation, thereby ensuring It improves charging safety, thus solving the problem in the existing technology that lacks a technical solution to control the charging process of the power battery to ensure that the charging current is large enough without causing lithium deposition when the SOC cannot be accurately obtained.

In one implementation, during the constant voltage charging process, controlling the phased constant voltage charging of the battery according to the requested current value includes:

According to the current requested current value being less than the preset current threshold corresponding to the current constant voltage charging stage, obtain the preset constant voltage threshold corresponding to the preset current threshold;

According to the preset constant voltage threshold, the next stage of constant voltage charging is performed. Through staged constant voltage charging, the charging current is ensured to be large enough without causing lithium deposition, thereby ensuring charging safety.

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

According to the real-time voltage value, real-time current value and real-time maximum voltage value of the battery cell, the difference between the real-time maximum voltage value and the preset constant voltage threshold is maintained at a preset error corresponding to the current constant voltage charging stage. Within the range, the voltage accuracy of constant voltage charging is ensured.

In one implementation, the method further includes:

In the final constant voltage charging stage, the battery is controlled to enter the constant current charging stage according to the fact that the requested current value is less than or equal to the preset minimum current threshold, and the preset minimum current threshold is less than or equal to the at least one preset current. The minimum value among the lower limits of the value interval. The constant current charging stage can ensure that the charging current value is maintained at a high level and ensures a high charging speed.

In one implementation, the method further includes:

In the constant current charging stage, charging is stopped 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, thereby ensuring that the battery is charged with sufficient power.

In one implementation, controlling the battery to enter the constant current charging stage includes: controlling the constant current charging of the battery according to the preset threshold, which can ensure that the charging current value is maintained at a high level, ensuring that Higher charging speed.

In one implementation, the control performs constant current charging of the battery according to the preset threshold, including:

Controlling the difference between the actual charging current value and the preset current threshold to remain within the second preset difference interval, charging the battery can ensure that the charging current value is maintained at a higher level, ensuring higher charging speed.

In one implementation, before controlling the battery to enter the constant voltage charging stage according to the maximum voltage value of the battery cell reaching a first preset condition, the method further includes:

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

The battery is charged at a constant current according to the adaptive charging current value. By controlling the charging of the battery according to the obtained adaptive charging current value, charging safety and maximum charging speed can be ensured.

In one implementation, obtaining the adaptive charging current value based on the real-time temperature and real-time voltage or real-time SOC of the battery includes:

According to the real-time SOC or the real-time voltage, combined with the real-time temperature, the corresponding adaptive charging current value is obtained by looking up the charging window table. By controlling the charging of the battery based on the adaptive charging current value obtained by looking up the table, charging safety and maximum charging speed in the constant current charging stage can be ensured.

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

The difference between the actual charging current value and the adaptive charging current value is controlled to be maintained within a first preset difference interval, and the battery is charged at a constant current. By controlling the difference between the actual charging current value and the adapted charging current value to keep the battery charged within the first preset interval, charging safety and a large charging speed during constant current charging can be ensured.

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

The first control module is used to control the constant voltage charging of the battery according to the maximum voltage value of the cell cell of the battery being greater than or equal to the preset maximum voltage threshold;

The second control module is used to control the phased constant voltage charging of the battery according to the requested current value during the constant voltage charging process.

The battery charging control device provided by the embodiment of the present application controls the constant voltage charging of the battery according to the maximum voltage value of the cell cell of the battery being greater than or equal to the preset maximum voltage threshold. During the constant voltage charging process, the battery is charged according to the requested current value. size, controlling the staged constant voltage charging of the battery. There is no need to obtain SOC to control the charging process of the power battery. Through staged constant voltage charging, it is achieved to ensure that the charging current is large enough without causing lithium precipitation, thereby ensuring It improves charging safety, thus solving the problem in the existing technology that lacks a technical solution to control the charging process of the power battery to ensure that the charging current is large enough without causing lithium deposition when the SOC cannot be accurately obtained.

In a third aspect, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement any of the above battery charging control methods. The electronic device can achieve the same beneficial technical effects as the above-mentioned battery charging control method.

In a fourth aspect, a computer-readable storage medium is provided, with a computer program stored thereon, and the program is executed by a processor to implement any of the above battery charging control methods. The computer-readable storage medium can achieve the same beneficial technical effects as the above-mentioned battery charging control method.

In a fifth aspect, a power device is provided, including a power battery and the electronic device of the third aspect. The power battery is used to provide electric energy, and the electronic device is used to perform any of the above battery charging control methods on the power battery. This power device can achieve the same beneficial technical effects as the above-mentioned battery charging control method.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on the drawings without exerting creative efforts.

Figure 1 is a voltage curve diagram during the charging process of a lithium iron phosphate material battery.

Figure 2 is a flow chart of a battery charging control method provided by an embodiment of the present application.

Figure 3 is the functional schematic diagram of the PID control algorithm.

Figure 4 is a flow chart of using the first difference as the feedback value for negative feedback PID adjustment to adjust the real-time charging voltage value in some embodiments of the present application.

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

Figure 6 is a structural block diagram of a battery charging control device provided by another embodiment of the present application.

Figure 7 is a structural block diagram of an electronic device provided by another embodiment of the present application.

Figure 8 is a schematic diagram of a computer-readable storage medium provided by another embodiment of the present application.

Figure 9 is a structural block diagram of a power device provided by another embodiment of the present application.

Detailed ways

The embodiments of the present application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

In the description of this application, it should be noted that, unless otherwise stated, "plurality" means more than two; the terms "upper", "lower", "left", "right", "inside", " The orientation or positional relationship indicated such as "outside" is only for the convenience of describing the present application and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. Application restrictions. Furthermore, the terms "first," "second," "third," etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable error range. "Parallel" is not parallel in the strict sense, but within the allowable error range.

The directional words appearing in the following description are the directions shown in the figures and do not limit the specific structure of the present application. In the description of this application, it should also be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. Detachable connection, or integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application may be understood based on specific circumstances.

With the development of science and technology and the advancement of the times, new energy vehicles can effectively promote energy conservation and emission reduction due to their good environmental performance, low noise, and low cost of use. They can meet environmental protection requirements and are conducive to the sustainable development of social economy. Its market share has been increasing. New energy vehicles use power batteries as their power source, of which lithium-ion batteries are the most commonly used type of power battery.

Currently, electric vehicles usually choose lithium-ion battery systems as their power source. Since lithium-ion batteries are chemical system products, the charging capacity of lithium ions is restricted by the multi-step chemical reactions inside the battery. The inventor of this application discovered that during the charging process, electrons move from the positive electrode to the negative electrode outside the battery. In synchronization with the movement of electrons, the lithium ions in the positive electrode solid phase diffuse from the bulk phase to the surface, and charge transfer occurs at the solid/liquid interface. ; It reaches the anode surface through liquid phase mass transfer, passes through the solid-liquid interface film (Solid Eletrolyte Interface-SEI) at the anode interface, enters the graphite surface, and then diffuses into the anode (usually graphite) with the electronic system waiting in the anode conductive network. Bulk phase lattice; since graphite has layered channels, when lithium ions are embedded in the channels and form carbon-lithium compounds with carbon, graphite interlayer compounds such as LiC _x (x=1~6) are formed, and then solid-phase transmission occurs in the graphite; As the amount of lithium embedded in graphite increases, the value of Corresponding to the above-mentioned lithium insertion chemical phase transition, a potential platform appears near N ₁ V, N ₂ V, and N ₃ V (vs Li ⁺ /Li) on the charge and discharge curve; when the lithium ion insertion amount is greater than 50%, The potential of the graphite negative electrode of the lithium-ion battery will gradually decrease from N ₂ V to N ₃ V, corresponding to the transition of the lithium ion insertion amount from LiC ₁₂ to LiC ₆ .

Lithium precipitation in the negative electrode is the main cause of safety accidents in lithium-ion batteries. There are many factors leading to lithium precipitation in the negative electrode of lithium-ion batteries. Excessive charging current is one of the main reasons for lithium precipitation in the negative electrode. Lithium precipitation in the negative electrode will reduce the thermal stability of the battery negative electrode. At the same time, the lithium dendrites formed may pierce the separator, causing the positive and negative electrodes to short-circuit, resulting in battery safety accidents.

During the charging process of electric vehicles, how to ensure that the charging current is large enough without causing lithium deposition during charging are two aspects that require a comprehensive balance. In addition, the inventor also found that during the charging process, the higher the state of charge (State Of Charge-SOC), the greater the amount of embedded lithium, and the smaller the charging capacity current of the battery cell. Therefore, under the same ambient temperature, the charging capacity of the low-end SOC area is higher than that of the high-end SOC area; as the SOC state increases, the charging capacity of the battery cell gradually decreases.

Therefore, during the charging process of electric vehicles, the charging request current is usually calculated based on the SOC state value of the lithium-ion battery or the voltage value of the single cell during the charging process. However, the battery cells of the lithium iron phosphate system have different characteristics due to the characteristics of the lithium iron phosphate material. Chemical properties: Lithium iron phosphate undergoes a two-phase reaction during the charge and discharge process. According to Gibbs' phase law, degree of freedom = number of material components - number of phases + external factors. It can be calculated that the reaction of lithium iron phosphate material during the charge and discharge process The voltage value remains unchanged and there is a voltage platform area; therefore, it has a flat charge and discharge platform around 3.4V; due to the voltage platform area problem of the lithium iron phosphate battery, the SOC calculation of the battery cell is inaccurate, and the SOC value during charging cannot be guaranteed. accuracy requirements.

The lithium iron phosphate material battery has a large charging rate in the low-end SOC range and a small charging rate in the high-end SOC range. Therefore, during the charging process, due to the polarization of the lithium-ion cell, the lithium iron phosphate material battery has a higher charging rate in the mid-to-low-end SOC range. The charging dynamic voltage in this range is higher than the dynamic voltage in the high-end SOC range, as shown in Figure 1. When the SOC calculation is inaccurate, how to ensure safe and rapid charging of the cells of lithium iron phosphate battery is a technical problem that the battery management system (BMS) needs to solve.

The inventor also discovered that constant voltage charging is an effective charging method that balances charging time and charging safety. When the battery enters the constant voltage charging stage, because the positive electrode of the battery is constantly releasing lithium ions, the potential is gradually increasing; while the negative electrode is gradually increasing. As lithium ions continue to be embedded, the potential is gradually decreasing; when constant voltage charging is performed, the positive electrode potential is continuously increasing, and the current gradually decreases, which will cause the negative electrode potential to slowly rise; therefore, when entering the constant voltage charging process, The negative electrode potential does not have a lithium precipitation potential as low as 0V. During the constant voltage charging process, it will not cause lithium precipitation in the lithium-ion battery and cause safety accidents.

For ease of description, the application of power batteries to new energy vehicles (power vehicles) will be used as an example for description below. The battery in the embodiment of the present application can be a single cell, a battery module or a battery pack, which is not limited here. In terms of application scenarios, batteries can be used in power devices such as cars and ships. For example, it can be used in power vehicles to power the motors of power vehicles and serve as the power source of electric vehicles. The battery can also power other electrical devices in electric vehicles, such as in-car air conditioners, car players, etc.

In order to solve the technical problem of being unable to ensure that the charging current is large enough while ensuring that lithium precipitation does not occur when the SOC calculation is inaccurate during the charging process, the battery charging control method in the embodiment of the present application is based on the fact that the maximum voltage value of the battery cell is greater than Or equal to the preset maximum voltage threshold, the constant voltage charging of the battery is controlled. During the constant voltage charging process, the battery is controlled to be charged at a staged constant voltage according to the requested current value. There is no need to obtain the SOC to charge the power battery. Control is carried out to ensure that the charging current is large enough without causing lithium precipitation through staged constant voltage charging, thereby ensuring charging safety. Thus, when the SOC cannot be accurately obtained, the power battery charging process is controlled to ensure charging. The current is large enough without causing lithium deposition during charging, thereby ensuring charging safety and realizing safe and fast charging of the battery.

As shown in Figure 2, one embodiment of the present application provides a battery charging control method, including steps S10 to S20.

The execution subject of the battery charging control method may be the battery management system BMS. For example, when the high voltage on the vehicle enters fast charging, the charging gun is inserted for charging. The charging pile and the vehicle complete information exchange, and the vehicle and the battery management system (BMS) complete internal communication. The battery management system (BMS) responds to the current voltage , temperature and SOC and other information calculate the acceptable charging capacity of the battery cell and send it to the vehicle system and the charging pile. When the charging pile receives the charging request current-related information sent by the BMS, it responds promptly and outputs the relevant requested charging current. The battery management system obtains the maximum output current value of the charging pile based on the interactive information of the charging pile, and the battery management system charges based on the maximum output current value of the charging pile. The battery includes at least one cell, which may be a cell made of lithium iron phosphate material.

S10. Control the constant voltage charging of the battery according to the fact that the maximum voltage value of the battery cell is greater than or equal to the preset maximum voltage threshold.

When the maximum voltage value of the battery cell is greater than or equal to the preset maximum voltage threshold, the battery is controlled to enter the constant voltage charging stage. Specifically, the maximum voltage value of the battery cell during the charging process is detected in real time. When the maximum voltage value of the battery cell is greater than or equal to the preset maximum voltage threshold Volt_Max, the battery is controlled to enter the constant voltage charging stage. The preset maximum voltage threshold can be, for example, 3.0V, 3.2V or 3.5V, and can be set according to actual needs.

S20. During the constant voltage charging process, the battery is controlled to be charged at constant voltage in stages according to the requested current value. Through staged constant voltage charging, the charging current is ensured to be large enough without causing lithium deposition, thereby ensuring charging safety.

In some embodiments, according to the current request current value being less than the preset current threshold corresponding to the current constant voltage charging stage, the preset constant voltage threshold corresponding to the preset current threshold is obtained; according to the preset constant voltage threshold, the next step is performed. stages of constant voltage charging.

For example, the current requested current value is 0.7A, and the preset current threshold corresponding to the current constant voltage charging stage is 0.8A. Since the current requested current value of 0.7A is smaller than the preset current threshold 0.8A corresponding to the current constant voltage charging stage, It is determined that the preset constant voltage threshold corresponding to the preset current threshold of 0.8A is 3.5V, and then the next stage of constant voltage charging is performed according to the preset constant voltage threshold of 3.5V.

For example, performing the next stage of constant voltage charging according to the preset constant voltage threshold may include: adjusting the real-time maximum voltage value to the predetermined value according to the real-time voltage value, real-time current value and real-time maximum voltage value of the cell cell. Assuming that the difference between the constant voltage thresholds is maintained within a preset error interval corresponding to the current constant voltage charging stage, the voltage accuracy of constant voltage charging is ensured.

For example, when performing constant voltage charging according to the preset constant voltage threshold of 3.5V, based on the real-time voltage value, real-time current value and real-time maximum voltage value of the battery cell, a closed-loop algorithm such as a PID algorithm is used to adjust the real-time maximum voltage value to the preset value. Assume that the difference between the constant voltage thresholds is maintained within the preset error interval [-0.15, 0.15] corresponding to the current constant voltage charging stage, that is, ensuring that -0.15V ≤ real-time maximum voltage value -3.5V ≤ 0.15V, thereby ensuring the real-time maximum voltage The interval to which the value belongs is [3.35,3.65]V.

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

Specifically, the adjustment method may adopt a closed-loop algorithm adjustment method, such as a PID adjustment algorithm. As shown in Figure 3, the PID control algorithm is a control algorithm that combines the three operating links of proportion, integral and differential. It is based on the input deviation value and performs operations according to the functional relationship of proportion, integral and differential. The operation results are used to control output.

As shown in Figure 4, in some implementations, step S20 may include steps S201 to S203:

S201. Determine the preset current value interval to which the requested current value belongs, and the corresponding preset constant voltage threshold and corresponding preset error interval corresponding to the corresponding preset current value interval.

Each preset current value interval in the at least one preset current value interval corresponds to a preset constant voltage threshold and a preset error interval respectively. As shown in Table 1, there are multiple preset current value intervals and corresponding preset constant voltage thresholds and corresponding preset error intervals.

Table 1

预设电流值区间：APreset current value range: A	预设恒压阈值：VPreset constant voltage threshold: V	预设误差区间：VPreset error interval: V
(1.0,1.2](1.0,1.2]	4.04.0	[-0.15,0.15][-0.15,0.15]
(0.6,0.9](0.6,0.9]	3.53.5	[-0.15,0.15][-0.15,0.15]
(0.3,0.6](0.3,0.6]	3.03.0	[-0.10,0.10][-0.10,0.10]
………	………	………
(0.1,0.2](0.1,0.2]	1.01.0	[-0.05,0.05][-0.05,0.05]
………	………	………

For example, if the current request current value is 0.7A, then according to Table 1, it can be determined 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. According to the real-time voltage value, real-time current value and real-time maximum voltage value of the battery cell, adjust so that the difference between the real-time maximum voltage value and the corresponding preset constant voltage threshold is maintained within the corresponding preset error interval.

Specifically, the adjustment method can be adjusted using a PID adjustment algorithm. During the constant voltage charging stage, the battery management system BMS performs closed-loop algorithm adjustments based on the real-time voltage value collected in real time by the battery cell, the real-time maximum voltage value collected in real time, and the real-time current value collected in real time, thereby maintaining the real-time maximum voltage value at the corresponding Preset constant voltage threshold ± deviation threshold. The closed-loop algorithm may be, for example, a PID adjustment algorithm.

S203. When the requested current value changes to belong to another preset current value interval, the requested current value is updated, and the cycle is executed to determine the preset current value interval to which the requested current value belongs, until the requested current value is less than or equal to the preset threshold. .

Specifically, during the constant voltage charging stage, the actual current value continuously decreases according to the adaptive adjustment of the dynamic performance of the battery cell. When the corresponding requested current value is less than the preset current threshold I_req_NumOne, the corresponding current value is found according to the preset current threshold I_req_NumOne. Constant voltage threshold V_Constant_One, the battery management system BMS adjusts the closed-loop algorithm (such as PID algorithm) based on the latest constant voltage threshold, combined with the real-time collected maximum voltage value and real-time collected current value, to maintain the battery's maximum voltage value at the constant voltage threshold. V_Constant_One±deviation threshold value; in the new constant voltage threshold constant voltage charging stage, when the actual current adaptively adjusts and continues to decrease according to the dynamic performance of the cell, when the requested current in the constant voltage stage is less than a certain current threshold, re-confirm A new constant voltage threshold for constant voltage charging. When the actual current value decreases, the preset current value range and the corresponding preset constant voltage threshold and preset error range can be tested and calibrated according to different cell material systems.

Corresponding to the example shown in Table 1, the preset threshold is 0.1A. Stop 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 requested current value is 0.7A, then according to Table 1, it can be determined 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 The interval is [-0.15, 0.15]. When the requested current value drops to 0.5A, according to Table 1, the interval to which 0.5A belongs can be re-determined as (0.3, 0.6], and the corresponding preset constant voltage threshold is 3.0V, and the corresponding The preset error interval is [-0.10, 0.10], that is, turning to S201 and executing the loop until the requested current value is less than or equal to the preset threshold 0.1A.

In some implementations, the method of this embodiment may also include:

S30. In the final constant voltage charging stage, the battery is controlled to enter the constant current charging stage based on the requested current value being less than or equal to the preset minimum current threshold. The preset minimum current threshold is less than or equal to each lower limit of at least one preset current value interval. The smallest value among the values. The constant current charging stage can ensure that the charging current value is maintained at a high level and ensures a high charging speed.

The final constant voltage charging stage can be the last n constant voltage charging stages, n is a positive integer. For example, the final constant voltage charging stage can be the last constant voltage charging stage, the last two constant voltage charging stages, or the last three constant voltage charging stages. Charging stage, etc., the value of n can be selected according to actual application needs, that is, the final constant voltage charging stage is a relatively late stage relative to the entire charging stage.

As shown in Table 1, the minimum value among the lower limits of each preset current value range is 0.1A. In this example, the preset threshold is 0.1A. When the requested current value is less than or equal to 0.1A, the battery is controlled to enter the constant current charging stage.

In some embodiments, controlling the battery to enter the constant current charging stage may include: controlling the constant current charging of the battery according to a preset threshold, which can ensure that the charging current value is maintained at a higher level and ensures a higher charging speed.

For example, controlling the constant current charging of the battery according to the preset threshold may include: controlling the difference between the actual charging current value and the preset current threshold to remain within the second preset difference interval, and charging the battery to ensure that The charging current value is kept at a high level to ensure a high charging speed.

For example, the battery management system BMS can send a request current value to the charging pile. The charging pile receives the charging request current-related information sent by the BMS and responds promptly and outputs the relevant requested charging current, thereby controlling the actual charging current value and the preset current threshold. The difference is maintained within the second preset difference interval, and the battery is charged. The BMS can compare the difference between the actual charging current value detected in real time and the preset current threshold with the second preset difference interval. When the difference exceeds the upper limit of the second preset difference interval, the BMS Send an instruction to reduce the charging current value to the charging pile, so that the charging current value output by the charging pile is reduced until the difference is within the second preset difference interval; when the difference is less than the second preset difference When the lower limit value of the interval is reached, the BMS sends an instruction to increase the charging current value to the charging pile, so that the charging current value output by the charging pile increases until the difference is within the second preset difference interval.

In some embodiments, the method further includes:

S40. In the constant current charging stage, charging stops when the voltage of the battery cell reaches the preset stop condition.

Specifically, stopping charging when the voltage of the battery cell reaches a preset stop condition may include: 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, thereby ensuring that the battery is charged. Insert enough power.

In some embodiments, before controlling the battery to enter the constant voltage charging stage according to the maximum cell cell voltage value of the battery reaching the first preset condition, the method further includes:

S00, control the constant current charging of the battery.

Specifically, step S00 may include:

S001. Obtain the adaptive charging current value based on the real-time temperature and real-time voltage or real-time SOC of the battery.

For example, step S001 may include: obtaining the corresponding adaptive charging current value by looking up the charging window table according to the real-time SOC or real-time voltage, combined with the real-time temperature. By controlling the charging of the battery based on the adaptive charging current value obtained by looking up the table, charging safety and maximum charging speed in the pre-charging stage can be ensured.

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

S002. Perform constant current charging on the battery according to the adaptive charging current value.

By controlling the constant current charging of the battery according to the obtained adaptive charging current value, a larger charging speed and charging safety can be ensured.

For example, step S002 may include: controlling the difference between the actual charging current value and the adapted charging current value to remain within a first preset difference interval to charge the battery. By controlling the difference between the actual charging current value and the adapted charging current value to keep the battery charged within the first preset difference interval, charging safety and a large charging speed in the precharge stage can be ensured.

As shown in Figure 6, another embodiment of the present application provides a battery charging control device, including:

The first control module is used to control constant voltage charging of the battery based on the maximum voltage value of the battery cell being greater than or equal to the preset maximum voltage threshold;

In some implementations, the second control module may include:

The first sub-module is used to obtain the preset constant voltage threshold corresponding to the preset current threshold according to the current requested current value being less than the preset current threshold corresponding to the current constant voltage charging stage;

The second sub-module is used to perform the next stage of constant voltage charging according to the preset constant voltage threshold.

In some embodiments, the second sub-module performs the next stage of constant voltage charging according to the preset constant voltage threshold, including:

According to the real-time voltage value, real-time current value and real-time maximum voltage value of the battery cell, the adjustment is made so that the difference between the real-time maximum voltage value and the preset constant voltage threshold is maintained within the preset error interval corresponding to the current constant voltage charging stage.

In some embodiments, the device further includes:

The third control module is used to control the battery to enter the constant current charging stage according to the requested current value being less than or equal to the preset minimum current threshold in the last constant voltage charging stage. The preset minimum current threshold is less than or equal to at least one preset current value. The minimum value among the lower limits of the interval.

In some embodiments, the device further includes:

The charging stop module is used to stop charging when the voltage of the battery cell is greater than or equal to the full charge cut-off voltage for a preset time during the constant current charging stage.

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

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

The difference between the actual charging current value and the preset current threshold is controlled to be maintained within a second preset difference interval, and the battery is charged.

In some embodiments, the device further includes a precharge module, which is used to control the battery before entering the constant voltage charging stage according to the maximum cell cell voltage value of the battery reaching the first preset condition. Perform precharge.

Specifically, the precharge module may include:

The adaptive charging current value acquisition unit is used to obtain the adaptive charging current value based on the real-time temperature and real-time voltage or real-time SOC of the battery;

The constant current charging unit is used for constant current charging of the battery according to the adaptive charging current value.

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

In some embodiments, performing constant current charging on the battery according to the adapted charging current value includes: controlling the difference between the actual charging current value and the adapted charging current value to remain within a first preset difference interval, and performing constant current charging on the battery. Stream charging.

The battery charging control device provided by the embodiment of the present application can control the constant voltage charging of the battery according to the maximum voltage value of the battery cell is greater than or equal to the preset maximum voltage threshold. During the constant voltage charging process, according to the requested current value The size of the battery is controlled by phased constant voltage charging. There is no need to obtain SOC to control the charging process of the power battery. Through phased constant voltage charging, it is achieved to ensure that the charging current is large enough without causing lithium precipitation, thus Charging safety is ensured, thus solving the problem in the existing technology that lacks a technical solution to control the charging process of the power battery to ensure that the charging current is large enough without causing lithium deposition when the SOC cannot be accurately obtained.

Another embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the computer program to implement any of the above embodiments. Battery charging control method. The electronic device may be, for example, a battery management system (BMS) or other device.

As shown in Figure 7, the electronic device 10 may include: a processor 100, a memory 101, a bus 102 and a communication interface 103. The processor 100, the communication interface 103 and the memory 101 are connected through the bus 102; the memory 101 stores information available in the processor. A computer program running on the computer 100. When the processor 100 runs the computer program, it executes the method provided by any of the foregoing embodiments of the application.

Among them, the memory 101 may include high-speed random access memory (RAM: Random Access Memory), or may also include non-volatile memory (non-volatile memory), such as at least one disk memory. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 103 (which can be wired or wireless), and the Internet, wide area network, local network, metropolitan area network, etc. can be used.

The bus 102 may be an ISA bus, a PCI bus, an EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. The memory 101 is used to store a program, and the processor 100 executes the program after receiving the execution instruction. The method disclosed in any of the embodiments of the present application can 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. During the implementation process, each step of the above method can be completed by instructions in the form of hardware integrated logic circuits or software in the processor 100 . The above-mentioned processor 100 can be a general-purpose processor, which can include a central processing unit (Central Processing Unit, CPU for short), a network processor (Network Processor, NP for short), etc.; it can also be a digital signal processor (DSP), a dedicated integrated processor Circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Each method, step and logical block diagram disclosed in the embodiment of this application can be implemented or executed. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly implemented by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field. The storage medium is located in the memory 101. The processor 100 reads the information in the memory 101 and completes the steps of the above method in combination with its hardware.

The electronic device provided by the embodiments of the present application and the method provided by the embodiments of the present application are based on the same inventive concept, and have the same beneficial effects as the methods adopted, run or implemented.

Another embodiment of the present application provides a computer-readable storage medium on which a computer program is stored, and the program is executed by a processor to implement the battery charging control method of any of the above embodiments.

The embodiment of the present application also provides a computer-readable storage medium corresponding to the method provided by the previous embodiment. Refer to Figure 8. The computer-readable storage medium shown is an optical disk 20, and a computer program ( That is, a program product), when the computer program is run by the processor, it will execute the method provided by any of the foregoing embodiments.

It should be noted that examples of computer-readable storage media may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), and other types of random access memory. Memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical and magnetic storage media will not be described in detail here.

The computer-readable storage medium provided by the above embodiments of the present application is based on the same inventive concept as the method provided by the embodiments of the present application, and has the same beneficial effects as the methods adopted, run or implemented by the application programs stored therein.

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

Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be described again here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.

A unit described as a separate component may or may not be physically separate. A component shown as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed to multiple network units. Some or all of the units can 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 can be integrated into one processing unit, each unit can exist physically alone, or two or more units can be integrated into one unit.

Functions may be stored in a computer-readable storage medium when implemented in the form of software functional units and sold or used as independent products. Based on this understanding, the technical solution of the present application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions. It is used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code. .

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present application. are covered by the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

A battery charging control method, characterized by including:

According to the maximum voltage value of the cell cell of the battery being greater than or equal to the preset maximum voltage threshold, control the constant voltage charging of the battery;

During the constant voltage charging process, the battery is controlled to be charged at constant voltage in stages according to the requested current value.
The method according to claim 1, characterized in that, during the constant voltage charging process, controlling the phased constant voltage charging of the battery according to the size of the requested current value includes:

According to the current requested current value being less than the preset current threshold corresponding to the current constant voltage charging stage, obtain the preset constant voltage threshold corresponding to the preset current threshold;

According to the preset constant voltage threshold, the next stage of constant voltage charging is performed.
The method of claim 2, wherein performing the next stage of constant voltage charging according to the preset constant voltage threshold includes:

According to the real-time voltage value, real-time current value and real-time maximum voltage value of the battery cell, the difference between the real-time maximum voltage value and the preset constant voltage threshold is maintained at a preset error corresponding to the current constant voltage charging stage. within the interval.
The method of claim 1, further comprising:

In the final constant voltage charging stage, the battery is controlled to enter the constant current charging stage according to the fact that the requested current value is less than or equal to the preset minimum current threshold, and the preset minimum current threshold is less than or equal to the at least one preset current. The minimum value among the lower limits of the value interval.
The method of claim 4, further comprising:

In the constant current charging stage, charging is stopped 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 according to claim 4, wherein the controlling the battery to enter the constant current charging stage includes: controlling the constant current charging of the battery according to the preset threshold.
The method according to claim 6, characterized in that the control performs constant current charging of the battery according to the preset threshold, including:

The difference between the actual charging current value and the preset current threshold is controlled to be maintained within a second preset difference interval, and the battery is charged.
The method according to claim 1, characterized in that:

Before controlling the battery to enter the constant voltage charging stage according to the maximum voltage value of the battery cell reaching the first preset condition, the method further includes:

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

The battery is charged at a constant current according to the adaptive charging current value.
The method of claim 8, wherein obtaining the adaptive charging current value based on the real-time temperature and real-time voltage or real-time SOC of the battery includes:

According to the real-time SOC or the real-time voltage, combined with the real-time temperature, the corresponding adaptive charging current value is obtained by looking up the charging window table.
The method of claim 8, wherein performing constant current charging on the battery according to the adaptive charging current value includes:

The difference between the actual charging current value and the adaptive charging current value is controlled to be maintained within a first preset difference interval, and the battery is charged at a constant current.
A battery charging control device, characterized by including:

The first control module is used to control the constant voltage charging of the battery according to the maximum voltage value of the cell cell of the battery being greater than or equal to the preset maximum voltage threshold;

The second control module is used to control the phased constant voltage charging of the battery according to the requested current value during the constant voltage charging process.
An electronic device, characterized in that it includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the program to implement claims 1- The battery charging control method according to any one of 10.
A computer-readable storage medium with a computer program stored thereon, characterized in that the program is executed by a processor to implement the battery charging control method as claimed in any one of claims 1-10.
A power device, characterized in that it includes a power battery and the electronic device as claimed in claim 13, the power battery is used to provide electric energy, and the electronic device is used to perform the power battery as claimed in claims 1-10 The battery charging control method described in any one of the above.