WO2023245572A1

WO2023245572A1 - Electric device and battery charging method and apparatus therefor, and medium

Info

Publication number: WO2023245572A1
Application number: PCT/CN2022/100897
Authority: WO
Inventors: 王海将; 李海力; 黄帅
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: CN117642954A

Abstract

Disclosed in the present application are an electric device and a battery charging method and apparatus therefor, and a medium. By applying the technical solution of the present application, the current charging stage of a battery can be determined in real time during a battery charging process. In addition, according to a comparison between a requested current value or the maximum cell voltage value reached in the battery and a current threshold value or a voltage threshold value of a corresponding charging stage, a corresponding constant-voltage charging mode or a constant-current charging mode is selected for switching. Therefore, the present application can not only prevent the problem of there being potential safety hazards due to a battery always being charged by using a constant-voltage or constant-current charging mode, but can also prevent the problem occurring in the related art of the charging efficiency not being high due to a battery charging function usually being limited by the regulation and control capability of a charging algorithm of a battery system.

Description

Charging methods, devices and media for electrical devices and their batteries

Technical field

This application relates to battery management technology, in particular to an electrical device and a charging method, device and medium for its battery.

Background technique

With the development of science and technology, more and more electrical devices will realize their operation functions by carrying batteries.

Taking the electrical device as an electric vehicle as an example, among related technologies, with the rapid popularization of new energy electric vehicles, charging time and charging safety have become one of the main concerns of many electric vehicle owners when using their cars in daily life. Especially during long-distance driving, increasing charging speed is one of the important solutions to alleviate the range anxiety that electric vehicle owners have when using electric vehicles.

However, in related technologies, the battery charging function is often limited by the control capability of the charging algorithm of the battery system, resulting in low charging efficiency.

Contents of the invention

Embodiments of the present application provide an electrical device and a charging method, device and medium for its battery. This solves the problem in related technologies that the battery charging function is often limited by the control capability of the charging algorithm of the battery system, resulting in low charging efficiency.

Among them, according to one aspect of the embodiments of the present application, a battery charging method is provided, including:

During the staged charging process of the battery, determine the current charging stage corresponding to the current battery status parameters;

Based on the current battery status parameters, the current threshold and the voltage threshold corresponding to the current charging stage, the battery is alternately charged with constant voltage or constant current.

By applying the technical solution of this application, the current charging stage of the battery can be determined in real time during the charging process of the battery. And based on the comparison between the requested current value or the maximum cell voltage value reached by the battery and the current threshold or voltage threshold of the corresponding charging stage. Choose to switch to the corresponding constant voltage charging method or constant current charging method. This not only avoids the potential safety hazards caused by always charging the battery with constant voltage or constant current charging. It also avoids the problem in related technologies that the battery charging function is often limited by the control capability of the charging algorithm of the battery system, resulting in low charging efficiency.

Optionally, in another embodiment based on the above method of the present application, based on the current battery status parameters, the current threshold and the voltage threshold corresponding to the current charging stage, the battery is alternately charged with constant voltage or constant current, including: if it is determined When the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, the battery is charged at a constant voltage using the voltage threshold; during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the corresponding voltage in the next charging stage. When the current threshold is reached, the battery is charged at a constant current at the current threshold, and the next charging stage is the next charging stage adjacent to the current charging stage. By applying the technical solutions of the embodiments of the present application, during the charging process of the battery, whether to switch to the constant voltage charging mode can be decided based on whether the maximum cell voltage value currently reached by the battery exceeds the voltage threshold corresponding to the current charging stage. And in the constant voltage charging mode, whether to switch to the constant current charging mode is determined based on whether the current requested current value of the battery exceeds the current threshold corresponding to the next charging stage. This achieves a battery charging method that can autonomously switch charging methods, thereby preventing potential safety hazards caused by always charging the battery in a constant voltage or constant current charging method.

Optionally, in another embodiment based on the above method of this application, if it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, performing constant voltage charging on the battery with the voltage threshold includes: if After it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold and the duration exceeds the first time period, the battery is charged at a constant voltage using the voltage threshold. By applying the technical solutions of the embodiments of the present application, during the charging process of the battery, only when the maximum cell voltage value currently reached by the battery exceeds the voltage threshold corresponding to the current charging stage, and only after a certain period of time. Decided to switch to constant voltage charging method. That is to say, it will switch to the constant voltage charging mode only when the maximum cell voltage of the battery is ensured to be continuously exceeded. This prevents the problem of low charging efficiency caused by always charging the battery with constant current charging.

Optionally, in another embodiment based on the above method of the present application, during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold corresponding to the next charging stage, the battery is constant-voltage based on the current threshold. Current charging includes: during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold and the duration exceeds the second time period, performing constant current charging on the battery with the current threshold. By applying the technical solutions of the embodiments of the present application, during the charging process of the battery, only when the current requested current value of the battery is less than the current threshold corresponding to the next charging stage of the current charging stage, and continuously It takes a certain amount of time to decide to switch to constant current charging. That is to say, it will only switch to the constant current charging mode when it is ensured that the battery's requested current value is continuously too low. This prevents potential safety hazards caused by always charging the battery in a constant voltage charging method.

Optionally, in another embodiment based on the above method of this application, constant voltage charging of the battery at a voltage threshold includes: controlling the maximum cell voltage of the battery within a preset voltage range by adjusting the current requested current value of the battery. , the preset voltage interval is obtained from the voltage threshold of the current stage. By applying the technical solutions of the embodiments of the present application, during the process of constant voltage charging of the battery, the maximum cell voltage of the battery can be controlled by adjusting the battery's requested current value in real time, and then based on the control of the maximum cell voltage of the battery. method to ensure charging in a constant voltage manner. To ensure that the battery can exert the maximum charging capacity of the battery core during the constant voltage charging process, and at the same time ensure the charging safety of the battery core.

Optionally, in another embodiment based on the above method of the present application, performing constant current charging on the battery with a current threshold includes: based on the current battery status parameters of the battery, controlling the requested current value of the battery to be within a preset current interval, The preset current interval is obtained from the current threshold of the current stage. By applying the technical solutions of the embodiments of the present application, during the process of constant current charging of the battery, the battery status parameters can be determined in real time to determine the matching request current value. Then, charging in a constant current mode is ensured according to the method of controlling the requested current value. This ensures that the battery can exert the maximum charging capacity of the battery core during constant current charging, while ensuring the charging safety of the battery core.

Optionally, in another embodiment based on the above method of the present application, after performing constant current charging on the battery at the current threshold, the method further includes: if it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage corresponding to the last charging stage. After the threshold value exceeds the third time period, it is determined that charging is completed, and the last charging stage is the charging stage corresponding to the maximum remaining power value in each charging stage. By applying the technical solutions of the embodiments of this application, during the process of constant current charging of the battery, if it is detected that the current maximum cell voltage exceeds the full charge cut-off voltage and continues for a period of time, it can be determined that the battery status has reached the full charge state. , thus ending the charging process. This prevents battery overcharge from affecting charging safety.

Optionally, in another embodiment based on the above method of the present application, determining the current charging stage corresponding to the current battery status parameters includes: collecting the current battery status parameters of the battery in real time during the charging process of the battery. The battery status parameters Including the battery core temperature value, remaining power value and voltage value; based on the battery core temperature value, remaining power value and voltage value, the current charging stage corresponding to the current battery status is determined. By applying the technical solution of this application, during the charging process of the battery, parameters such as the cell temperature value, remaining power value, and voltage value of the battery can be obtained in real time to determine the current charging stage of the battery. So that the corresponding constant voltage charging method or constant current charging method can be selected and switched subsequently based on this parameter. This not only avoids the potential safety hazards caused by always charging the battery with constant voltage or constant current charging. It also avoids the problem in related technologies that the battery charging function is often limited by the control capability of the charging algorithm of the battery system, resulting in low charging efficiency.

Optionally, in another embodiment based on the above method of the present application, before determining the current charging stage corresponding to the current battery status parameter, it further includes: detecting that the electrical device where the battery is located is connected to the charging device, Obtain the maximum output current value of the charging device; calculate the initial current value of the battery based on the current battery status parameters; when it is determined that the initial current value is less than or equal to the maximum output charging current value, charge the battery with the initial current value, and determine the The initial current value corresponds to the initial charging stage. By applying the technical solution of this application, after determining the initial current value of the corresponding battery based on the battery status parameters of the battery, the initial current value can be compared with the maximum output current value that the charging pile can achieve. This ensures that the battery is charged at the smaller current value between the initial current value and the maximum output current value. This not only ensures the safety of battery charging, but also improves the charging efficiency of the battery.

Optionally, in another embodiment based on the above method of the present application, after calculating the initial current value of the battery, it further includes: when it is determined that the initial current value is greater than the maximum output current value, charging the battery with the maximum output current value , and determine the initial charging stage corresponding to the maximum output charging current value. By applying the technical solution of this application, after determining the initial current value of the corresponding battery based on the battery status parameters of the battery, the initial current value can be compared with the maximum output current value that the charging pile can achieve. This ensures that the battery is charged at the smaller current value between the initial current value and the maximum output current value. This not only ensures the safety of battery charging, but also improves the charging efficiency of the battery.

Among them, according to another aspect of the embodiment of the present application, a battery charging device is provided, including: a determination module configured to determine the current charging value corresponding to the current battery status parameter during the phased charging process of the battery. Stage; the charging module is configured to alternately perform constant voltage charging or constant current charging on the battery based on the current battery status parameters, the current threshold and the voltage threshold corresponding to the current charging stage.

According to another aspect of the embodiment of the present application, an electrical device is provided, including:

memory for storing executable instructions; and

The display is configured to execute the executable instructions with the memory to complete the operation of any of the above battery charging methods.

According to yet another aspect of the embodiment of the present application, a computer-readable storage medium is provided, which is used to store computer-readable instructions. When the instructions are executed, the operations of any of the battery charging methods described above are performed.

The above description is only an overview of the technical solutions of the present application. In order to have a clearer understanding of the technical means of the present application, they can be implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and understandable. , the specific implementation methods of the present application are specifically listed below.

Description of the drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

The present application may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

Figure 1 is a schematic structural diagram of a power supply device applied to a battery proposed by this application;

Figure 2 is a schematic diagram of a battery charging method proposed in this application;

Figure 3 is a schematic diagram of the charging process of a battery proposed in this application;

Figure 4 is a schematic structural diagram of the battery charging device proposed in this application;

Figure 5 is a schematic diagram of the electrical device proposed in this application.

Detailed ways

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these examples do not limit the scope of the present application unless otherwise specifically stated.

At the same time, it should be understood that, for convenience of description, the dimensions of various parts shown in the drawings are not drawn according to actual proportional relationships.

The following description of at least one exemplary embodiment is merely illustrative in nature and is not intended to limit the application or its application or uses.

Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered a part of the specification.

It should be noted that similar reference numerals and letters refer to similar items in the following figures, so that once an item is defined in one figure, it does not need further discussion in subsequent figures.

In addition, the technical solutions in the various embodiments of the present application can be combined with each other, but it must be based on what a person of ordinary skill in the art can implement. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions is possible. It does not exist and is not within the protection scope required by this application.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of this application are only used to explain the functions of each component in a specific posture (as shown in the drawings). The relative positional relationship, movement conditions, etc., if the specific posture changes, the directional indication will also change accordingly.

A method for charging a battery according to an exemplary embodiment of the present application will be described below with reference to FIGS. 1-3 . It should be noted that the following application scenarios are only shown to facilitate understanding of the spirit and principles of the present application, and the implementation of the present application is not subject to any limitation in this regard. On the contrary, the embodiments of the present application can be applied to any applicable scenario.

Taking the electric device as a car as an example. Among related technologies, cars are one of the important means of transportation for human beings. With the advancement of the times, the per capita ownership of cars in China continues to increase and has entered thousands of households. Electric vehicles that use power batteries to drive vehicles are becoming more and more popular due to their environmentally friendly characteristics.

Furthermore, power batteries are the core component of electric vehicles. Among them, during the charging process of electric vehicles, the charging request current will be calculated based on the SOC status of the lithium-ion battery or the maximum/minimum voltage value of the single battery in the PACK. The traditional charging request current calculation method is usually; According to the maximum temperature/minimum temperature/and (maximum voltage/minimum voltage or maximum SOC/minimum SOC) during the charging process, check the charging stage table and take the smaller value as the charging current requirement of the battery pack; most lithium-ion battery systems The charging dynamic voltage will monotonically increase as the SOC state increases during the charging process. However, there are special batteries. Due to issues such as the over-temperature of the battery or the process capability of the battery during the charging process, the charging dynamic voltage of the lithium-ion battery during the charging process does not increase monotonically. As SOC increases, the voltage fluctuates and increases. Therefore, the same charging dynamic voltage will correspond to multiple charging rate values. For this system of cells, the charging stage is simply checked based on the real-time dynamic voltage of the cell. method is no longer applicable.

The applicant has noticed that there are at least the following problems in the prior art. That is, current electric vehicles usually choose lithium-ion battery systems as power sources. Since lithium-ion batteries are chemical system products, the charging ability of lithium ions is affected by the multi-step chemistry inside the battery. reaction constraints.

During the charging process, outside the battery, electrons move from the positive electrode to the negative electrode. In synchronization with the electron movement, 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; through liquid phase mass transfer, they reach the The surface of the negative electrode passes through the solid-liquid interface film (Solid Eletrolyte Interface-SEI) at the negative electrode interface and enters the graphite surface layer, and then diffuses into the bulk lattice of the negative electrode (usually graphite) with the electronic system waiting in the negative electrode conductive network; due to Graphite has layered channels. When lithium ions are embedded in the channels, they form carbon-lithium compounds with carbon, forming graphite interlayer compounds such as LiCx (x=1~6), which are then solid-phase transported in the graphite; as lithium is embedded in the graphite As the amount increases, the value of

Corresponding to the above-mentioned lithium insertion chemical phase transition, potential platforms appear near 0.21V, 0.12V, and 0.08V (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 0.12V to 0.08V, corresponding to the transition of the lithium ion insertion amount from LiC12 to LiC6;

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 cause the battery to The thermal stability of the negative electrode is reduced, and the lithium dendrites formed at the same time may pierce the separator, causing a short circuit of the positive and negative electrodes, resulting in battery safety accidents;

Furthermore, during the charging process of electric vehicles, how to ensure that the charging current is large enough without causing lithium deposition during charging is a contradiction that requires a comprehensive balance; during the charging process of lithium-ion batteries, the charging state of charge (State Of Charge- The higher the SOC), the more lithium is embedded, and the smaller the charging capacity current of the battery cell; therefore, at 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.

In addition, during the charging process of electric vehicles, the charging request current is calculated based on the SOC status of the lithium-ion battery or the maximum/minimum voltage value of the single battery in the PACK. The traditional charging request current calculation method is usually based on the charging process. The maximum temperature/minimum temperature/and (maximum voltage/minimum voltage or maximum SOC/minimum SOC) are combined in pairs to check the charging stage table and take the smaller value as the charging request current value of the battery pack. The table lookup method is usually divided into linear Table lookup method and stepped table lookup method;

The following example is used to explain the difference between linear interpolation table lookup and ladder lookup table. Assume that the charging rate corresponding to 10% SOC is 2.0C, and the charging rate corresponding to 20% SOC is 1.0C; then when the SOC is 15% SOC, According to the formula (15% SOC-10% SOC)/(20% SOC-10% SOC)*(2.0C-1.0C), the charging rate of linear interpolation is 1.5C;

The principle of the stepped table lookup is that when the SOC is in the 10-20% SOC range, the charging request magnification is 2.0C; when the SOC is greater than or equal to 20% SOC, the charging request magnification is 1.0C.

Among them, the charging stage of the lithium-ion battery is based on the actual calculation of the lithium deposition stage of the battery cell. The charging stage of the lithium-ion battery is equivalent to the lithium deposition stage of the battery cell to a certain extent; the charging stage of the lithium-ion battery changes with the SOC state. It changes with changes. Different SOC values correspond to different charging rates in the charging stage; the relationship between the charging stage and the change of the SOC state is not a simple linear relationship or a STEP relationship, so whether it is linear interpolation or STEP charging. , none of them can perfectly match the relationship between the battery's lithium precipitation phase and the SOC change during the charging process; and the SOC interval in the charging phase, when used in normal engineering projects, it is impossible to divide the SOC value interval into infinitesimal values, usually 5% Or 10% SOC interval; therefore, how to transition charging in the SOC interval is a scientific issue that needs to be studied and controlled by the battery management system.

Based on the above problems, embodiments of the present application propose a method of charging the battery using constant voltage charging. Among them, 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 As lithium ions continue to be embedded, the potential gradually decreases; when charged at constant voltage, the positive electrode potential continues to increase, and the current gradually decreases, which will cause the negative electrode potential to slowly rise.

Therefore, when entering constant voltage charging, the negative electrode potential does not have a lithium deposition potential as low as 0V. During the constant voltage charging process, it will not cause lithium deposition in the lithium-ion battery, leading to safety accidents; at the same time, the constant voltage charging process is based on the battery core. The reaction rate of the internal multi-step chemical reaction self-regulates to the process of rebalancing the multi-step kinetic reaction process inside the battery cell, so that the depolarization of the constant voltage charging current perfectly conforms to the depolarization kinetic curve of the battery cell; therefore, the constant Pressure charging can perfectly bring out the maximum charging capacity of the battery core while ensuring the charging safety of the battery core.

Embodiments of the present application provide an electrical device with a battery as a power source. The electrical device can be but is not limited to mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.

In one way, the battery pack in this application is rechargeable and dischargeable, such as lithium-ion battery, nickel-hydrogen battery, nickel-chromium battery, nickel-zinc battery, etc.

For the convenience of explanation in the following embodiments, a vehicle 1000 is used as an example in which an electrical device according to an embodiment of the present application is used.

Please refer to FIG. 1 , which is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 . The battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 . The vehicle 1000 may also include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .

In some embodiments of the present application, the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

In one way, this application also proposes a charging method, device and medium for an electrical device and its battery.

FIG. 2 schematically shows a flow chart of a battery charging method according to an embodiment of the present application. As shown in Figure 2, this method includes:

S201. During the staged charging process of the battery, determine the current charging stage corresponding to the current battery status parameters.

Furthermore, in the embodiment of the present application, the electrical device can start charging the battery in stages after receiving the charging start command. In one way, the charging start instruction can be an instruction generated after the user connects the electrical device to the charging device. As an example, the user can insert the charging plug of the electrical device into the power supply device (such as a charging pile) to enter charging.

In a possible implementation, when the charging pile and the electrical device complete information exchange, and the electrical device and the battery management system (BMS) complete internal communication, the battery management system (BMS) can calculate the current battery according to the internal calculation logic. The acceptable charging capacity of the battery cell is sent to the electrical device and charging pile. Further, when the charging pile receives the charging request current and related information sent by the BMS, it can respond and output the relevant requested charging current.

Among them, the BMS (battery management system) in the electrical device receives the charging start command acting on the battery. Among them, BMS is to intelligently manage and maintain each battery unit, prevent the battery from overcharging and over-discharging, extend the service life of the battery, and monitor the status of the battery.

In one way, the BMS battery management system unit includes a BMS battery management system, a control module, a display module, a wireless communication module, electrical equipment, a battery pack for powering the electrical equipment, and a battery pack for collecting battery information. The acquisition module, the BMS battery management system is connected to the wireless communication module and the display module respectively through the communication interface, the output end of the acquisition module is connected to the input end of the BMS battery management system, and the output end of the BMS battery management system is connected to the control module. The input end of the battery pack is connected, the control module is connected to the battery pack and electrical equipment respectively, and the BMS battery management system is connected to the server through the wireless communication module.

It should be noted that in the embodiment of the present application, the charging process of the battery can be implemented according to a charging stage set table including multiple charging stages. Each charging stage includes corresponding current thresholds, voltage thresholds and corresponding battery status parameters. In this way, during the subsequent staged charging process of the battery, the BMS can select the current charging stage corresponding to the current battery status parameters.

S202: Based on the current battery status parameters, the current threshold and the voltage threshold corresponding to the current charging stage, alternately perform constant voltage charging or constant current charging on the battery.

As an example, the charging stage set table includes charging stage 1 to charging stage 3, where:

Charging stage 1 includes battery status parameter a (for example, battery cell temperature value a, battery remaining capacity value a, and battery voltage value a) - current threshold a - voltage threshold a;

Charging stage 2 includes battery status parameter b (for example, battery cell temperature value b, battery remaining capacity value b, and battery voltage value b) - current threshold b - voltage threshold b;

Charging stage 3 includes battery status parameter c (for example, battery cell temperature value c, battery remaining capacity value c, and battery voltage value c) - current threshold c - voltage threshold c.

Further, during the process of charging the battery, it is necessary to monitor at least one of the current cell temperature value, remaining power value and voltage value of the battery in real time. As an example, when it is determined that the current cell temperature value of the battery reaches b, the remaining power value reaches b, and the voltage value reaches b, it can be determined that the current battery status parameters of the battery meet the charging process of reaching charging stage 2, and then it can be Based on the current threshold b and voltage threshold c corresponding to charging stage 2, constant voltage charging or constant current charging is selected for the battery.

Furthermore, during the process of charging the battery in a certain constant voltage charging state or constant current charging state, it is still necessary to monitor at least one of the current cell temperature value, remaining power value and voltage value of the battery in real time. As another example, for example, when it is determined that the current cell temperature value of the battery reaches c, the remaining power value reaches c, and the voltage value reaches c, it can be determined that the current battery status parameters of the battery meet the charging process of reaching charging stage 3, Then, based on the current threshold c and voltage threshold c corresponding to charging stage 3, you can choose to charge the battery in another way (that is, switch from constant voltage charging to constant current charging, or switch from constant current charging to constant voltage charging). . Thus, a technical solution is realized that alternately performs constant voltage charging or constant current charging on the battery during the charging process of the battery. This not only avoids the problem in related technologies that the battery charging function is often limited by the control capability of the charging algorithm of the battery system, resulting in low charging efficiency. It can also avoid potential safety hazards caused by always charging the battery with constant voltage or constant current charging.

In one way, as shown in Figure 3, taking the electrical device as an electric vehicle as an example, the battery charging method proposed in this application is further described in detail:

Step 1. The user inserts the plug gun into the charging pile so that the charging pile and the vehicle complete information interaction. The vehicle completes internal communication with the battery management system (BMS). The battery management system obtains the maximum output of the charging pile based on the interaction information of the charging pile. Current value and other information.

Furthermore, in the initial stage of charging, the battery management system needs to comprehensively evaluate the temperature/voltage/SOC status of the current cell of the battery to calculate the corresponding initial charging current and initial charging stage (the initial charging stage Step is the nth Step( n=0,1,2...), the following takes the initial charging stage as charging stage 1 as an example), and the battery is charged with this initial charging current.

Step 2. During the charging process, as the SOC state of the battery gradually increases, the cell voltage is also gradually rising. When the battery management system detects that the maximum voltage value of a single cell in the battery is greater than or equal to the value corresponding to charging stage 1 After the voltage threshold is 5V and continues for a period of time (i.e., the first time period), it is determined that the battery charging process enters the constant voltage charging state.

Step 3. When the battery charging process enters the constant voltage charging state, the battery management system (BMS) needs to perform charging based on the maximum current capacity value of the battery cell, as well as the real-time collected maximum cell voltage value and current requested current value. The closed-loop algorithm is adjusted to maintain the maximum cell voltage value of the battery within a preset voltage range (for example, the voltage threshold ± deviation threshold corresponding to charging stage 1). Then, the purpose of constant current charging of the battery is achieved by controlling the maximum cell voltage of the battery within a preset voltage range.

Step 4. When the battery charging process enters the constant voltage charging state, the actual charging current of the battery will continuously and adaptively decrease according to the dynamic capability of the battery cell. Among them, when the current requested current value of the battery is less than or equal to the current threshold 3A corresponding to charging stage 2 (i.e., the next (n+1) charging step), and continues for a period of time (i.e., the second time period), it is determined to exit the constant state. voltage charging and enter the constant current charging process.

In one method, the constant current charging process can determine the current requested current value based on the current temperature/voltage/SOC status of the battery.

Step 5. Repeat the charging process of steps 2 to 4 above until the current requested current value of the battery is detected to be less than or equal to the current threshold 1A corresponding to charging stage 5 (i.e., the last charging step), and continues for a period of time (i.e., the second time section), it is determined to exit the current constant voltage charging and enter the constant current charging process.

Step 6. During the constant current charging process, as the SOC state of the battery gradually increases, the cell voltage is also gradually rising. When the battery management system detects that the maximum voltage value of a single cell in the battery is greater than or equal to charging stage 5, After the corresponding voltage threshold is 10V (i.e., the full charge cut-off voltage) and continues for a period of time (i.e., the first time period), it is determined that the battery charging process is over.

Optionally, in another embodiment based on the above method of the present application, based on the current battery status parameters, the current threshold and the voltage threshold corresponding to the current charging stage, the battery is alternately charged with constant voltage or constant current, including: if it is determined When the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, the battery is charged at a constant voltage using the voltage threshold; during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the corresponding voltage in the next charging stage. When the current threshold is reached, the battery is charged at a constant current at the current threshold, and the next charging stage is the next charging stage adjacent to the current charging stage.

In one way, the process of switching to the constant voltage charging mode in this application is based on whether the maximum cell voltage of the battery exceeds the voltage threshold corresponding to the current charging stage. It is understandable that during the charging process, as the battery SOC status gradually increases, the cell voltage will also increase accordingly. Excessive voltage may cause safety hazards to the battery during the charging process. Therefore, in order to avoid this problem, this application can determine whether to use the battery based on real-time monitoring of whether the cell voltage is greater than the voltage threshold corresponding to the current charging stage. Charge using constant voltage charging method.

In another way, in this application, whether to switch to the constant current charging mode is determined by whether the current value of the battery is less than the current threshold corresponding to the next charging stage of the current charging stage. It is understandable that during the constant voltage charging process, the actual charging current will continue to adaptively decrease according to the dynamic capabilities of the battery cell. Too small a voltage may lead to low charging efficiency during the charging process. Therefore, in order to avoid this problem, this application can determine whether the requested current value is less than the current threshold corresponding to the next charging stage based on real-time monitoring. Charging is done using constant current charging.

It should be noted that in the embodiment of the present application, the voltage threshold and current threshold corresponding to each charging stage are preset.

By applying the technical solutions of the embodiments of the present application, during the charging process of the battery, whether to switch to the constant voltage charging mode can be decided based on whether the maximum cell voltage value currently reached by the battery exceeds the voltage threshold corresponding to the current charging stage. And in the constant voltage charging mode, whether to switch to the constant current charging mode is determined based on whether the current requested current value of the battery exceeds the current threshold corresponding to the next charging stage. This achieves a battery charging method that can autonomously switch charging methods, thereby preventing potential safety hazards caused by always charging the battery in a constant voltage or constant current charging method.

Optionally, in another embodiment based on the above method of this application, if it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, performing constant voltage charging on the battery with the voltage threshold includes: if After it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold and the duration exceeds the first time period, the battery is charged at a constant voltage using the voltage threshold. By applying the technical solutions of the embodiments of the present application, during the charging process of the battery, only when the maximum cell voltage value currently reached by the battery exceeds the voltage threshold corresponding to the current charging stage, and only after a certain period of time. Decided to switch to constant voltage charging method. That is to say, it will switch to the constant voltage charging mode only when the maximum cell voltage of the battery is ensured to be continuously exceeded. This prevents the problem of low charging efficiency caused by always charging the battery in a constant current charging mode.

Optionally, in another embodiment based on the above method of the present application, during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold corresponding to the next charging stage, the battery is constant-voltage based on the current threshold. Current charging includes: during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold and the duration exceeds the second time period, performing constant current charging on the battery with the current threshold.

By applying the technical solutions of the embodiments of the present application, during the charging process of the battery, only when the current requested current value of the battery is less than the current threshold corresponding to the next charging stage of the current charging stage, and continuously It takes a certain amount of time to decide to switch to constant current charging. That is to say, it will only switch to the constant current charging mode when it is ensured that the battery's requested current value is continuously too low. This prevents potential safety hazards caused by always charging the battery in a constant voltage charging method.

It should be noted that this application does not specifically limit the first time period and the second time period. For example, they can be the same value or different values. In one method, it can be 5 seconds or 10 seconds.

Optionally, in another embodiment based on the above method of this application, constant voltage charging of the battery at a voltage threshold includes: controlling the maximum cell voltage of the battery within a preset voltage range by adjusting the current requested current value of the battery. , the preset voltage interval is obtained from the voltage threshold of the current stage.

It should be noted that in this application, when the maximum cell voltage of the battery is about to exceed the upper limit of the preset voltage interval, this can be achieved by adjusting the current request current value of the battery to become smaller. Or, when it is detected that the maximum cell voltage of the battery is about to exceed the lower line of the preset voltage interval, this can be achieved by adjusting the current requested current value of the battery to become larger.

By applying the technical solutions of the embodiments of the present application, during the process of constant voltage charging of the battery, the maximum cell voltage of the battery can be controlled by adjusting the battery's requested current value in real time, and then based on the control of the maximum cell voltage of the battery. method to ensure charging in a constant voltage manner. To ensure that the battery can exert the maximum charging capacity of the battery core during the constant voltage charging process, and at the same time ensure the charging safety of the battery core.

Optionally, in another embodiment based on the above method of the present application, performing constant current charging on the battery with a current threshold includes: based on the current battery status parameters of the battery, controlling the requested current value of the battery to be within a preset current interval, The preset current interval is obtained from the current threshold of the current stage.

By applying the technical solutions of the embodiments of the present application, during the process of constant current charging of the battery, the battery status parameters can be determined in real time to determine the matching request current value. Then, charging in a constant current mode is ensured according to the method of controlling the requested current value. This ensures that the battery can exert the maximum charging capacity of the battery core during constant current charging, while ensuring the charging safety of the battery core.

Optionally, in another embodiment based on the above method of the present application, after performing constant current charging on the battery at the current threshold, the method further includes: if it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage corresponding to the last charging stage. After the threshold value exceeds the third time period, it is determined that charging is completed, and the last charging stage is the charging stage corresponding to the maximum remaining power value in each charging stage.

By applying the technical solutions of the embodiments of this application, during the process of constant current charging of the battery, if it is detected that the current maximum cell voltage exceeds the full charge cut-off voltage and continues for a period of time, it can be determined that the battery status has reached the full charge state. , thus ending the charging process. This prevents battery overcharge from affecting charging safety.

Optionally, in another embodiment based on the above method of the present application, before determining the current charging stage corresponding to the current battery status parameter, it further includes: detecting that the electrical device where the battery is located is connected to the charging device, Obtain the maximum output current value of the charging device; calculate the initial current value of the battery based on the current battery status parameters; when it is determined that the initial current value is less than or equal to the maximum output charging current value, charge the battery with the initial current value, and determine the The initial current value corresponds to the initial charging stage.

In this application, in the process of determining the initial current value, the true maximum charging current capability of the current battery core can be determined by looking up a table based on the obtained battery SOC value and the battery's current maximum/minimum temperature value and other battery status parameters. (i.e. the maximum charging current value).

Furthermore, it is necessary to compare the maximum charging current value with the maximum output current value sent by the charging pile to the entire vehicle, and select the smaller charging current value as the initial charging current value. And determine the initial charging stage corresponding to the initial current value.

By applying the technical solution of this application, after determining the initial current value of the corresponding battery based on the battery status parameters of the battery, the initial current value can be compared with the maximum output current value that the charging pile can achieve. To ensure that the battery is charged with the smaller current value between the initial current value and the maximum output current value. This not only ensures the safety of battery charging, but also improves the charging efficiency of the battery.

Optionally, in another embodiment of the present application, as shown in FIG. 4 , the present application also provides a battery charging device. Among them, include:

The determination module 301 is configured to determine the current charging stage corresponding to the current battery status parameter during the staged charging process of the battery;

The charging module 302 is configured to alternately perform constant voltage charging or constant current charging on the battery based on the current battery status parameter, the current threshold and the voltage threshold corresponding to the current charging stage.

In another implementation of the present application, the charging module 302 is configured as:

If it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, perform constant voltage charging of the battery with the voltage threshold;

During the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold corresponding to the next charging stage, the battery is charged with constant current at the current threshold, and the next charging stage is the next charging stage adjacent to the current charging stage.

If it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold and the duration exceeds the first time period, the battery is charged at a constant voltage using the voltage threshold.

During the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold and the duration exceeds the second time period, the battery is charged with a constant current using the current threshold.

By adjusting the current requested current value of the battery, the maximum cell voltage of the battery is controlled to be in a preset voltage interval, and the preset voltage interval is obtained by the voltage threshold of the current stage.

Based on the current battery status parameters of the battery, the requested current value of the battery is controlled to be within a preset current interval, and the preset current interval is obtained from the current threshold of the current stage.

If it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the last charging stage and exceeds the third time period, charging is determined to be completed. The last charging stage corresponds to the maximum remaining power value in each charging stage. charging stage.

In another implementation of the present application, the determination module 301 is configured as:

During the charging process of the battery, the current battery status parameters of the battery are collected in real time. The battery status parameters include battery core temperature value, remaining power value and voltage value;

Based on the cell temperature value, remaining power value and voltage value of the battery, the current charging stage corresponding to the current battery state is determined.

When it is detected that the electrical device where the battery is located is connected to the charging device, obtain the maximum output current value of the charging device;

Calculate the initial current value of the battery based on the current battery status parameters of the battery;

When it is determined that the initial current value is less than or equal to the maximum output charging current value, the battery is charged with the initial current value, and an initial charging stage corresponding to the initial current value is determined.

When it is determined that the initial current value is greater than the maximum output current value, the battery is charged with the maximum output current value, and an initial charging stage corresponding to the maximum output charging current value is determined.

Figure 5 is a logical structural block diagram of an electrical device according to an exemplary embodiment. For example, the battery 400 may include an electrical device carrying the battery.

In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions, such as a memory including instructions, is also provided. The instructions can be executed by a battery processor to complete the above-mentioned charging method of the battery. The method includes: During the staged charging process of the battery, the current charging stage corresponding to the current battery status parameter is determined; based on the current battery status parameter, the current threshold and the voltage threshold corresponding to the current charging stage, the battery is alternately charged Voltage charging or constant current charging. Optionally, the above instructions can also be executed by the processor of the battery to complete other steps involved in the above exemplary embodiments. For example, non-transitory computer-readable storage media may be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

In an exemplary embodiment, an application program/computer program product is also provided, including one or more instructions, which can be executed by a processor of the battery to complete the above battery charging method. The method The method includes: during the staged charging process of the battery, determining the current charging stage corresponding to the current battery status parameter; based on the current battery status parameter, the current threshold and the voltage threshold corresponding to the current charging stage, alternately charging the The battery is charged with constant voltage or constant current. Optionally, the above instructions can also be executed by the processor of the battery to complete other steps involved in the above exemplary embodiments.

FIG. 5 is an example diagram of battery 400. Those skilled in the art can understand that the schematic diagram 5 is only an example of the battery 400 and does not constitute a limitation of the battery 400. The battery 400 may include more or fewer components than shown, or some components may be combined, or different components may be used, such as The battery 400 may also include input and output devices, network access devices, buses, etc.

The so-called processor 402 can be a central processing unit (Central Processing Unit, CPU), or other general-purpose processor, digital signal processor (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general processor can be a microprocessor or the processor 402 can also be any conventional processor. The processor 402 is the control center of the battery 400 and uses various interfaces and lines to connect various parts of the entire battery 400 .

The memory 401 can be used to store computer readable instructions 403. The processor 402 implements various functions of the battery 400 by running or executing computer readable instructions or modules stored in the memory 401 and calling data stored in the memory 401. The memory 401 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the storage data area may store a program based on Data created by the use of battery 400, etc. In addition, the memory 401 may include a hard disk, memory, plug-in hard disk, smart memory card (Smart Media Card, SMC), secure digital (Secure Digital, SD) card, flash memory card (Flash Card), at least one disk storage device, flash memory device, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM) or other non-volatile/volatile storage devices.

If the integrated modules of the battery 400 are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the processes in the methods of the above embodiments, and can also be completed by instructing relevant hardware through computer-readable instructions. The computer-readable instructions can be stored in a computer-readable storage medium. When executed by the processor, the computer-readable instructions can implement the steps of each of the above method embodiments.

Other embodiments of the present application will be readily apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary technical means in the technical field that are not disclosed in this application. . It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It is to be understood that the present application is not limited to the precise structures described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

A battery charging method, characterized by including:

During the staged charging process of the battery, determine the current charging stage corresponding to the current battery status parameters;

Based on the current battery status parameters, the current threshold and the voltage threshold corresponding to the current charging stage, the battery is alternately charged with constant voltage or constant current.
The method of claim 1, wherein the battery is alternately charged with constant voltage or constant current based on the current battery status parameter, the current threshold and the voltage threshold corresponding to the current charging stage, include:

If it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, perform constant voltage charging of the battery with the voltage threshold;

During the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold corresponding to the next charging stage, the battery is charged with constant current at the current threshold, and the next charging stage is the next charging stage adjacent to the current charging stage.
The method according to claim 2, characterized in that, if it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the current charging stage, the battery is constant-charged with the voltage threshold. Voltage charging, including:

If it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold and the duration exceeds the first time period, the battery is charged at a constant voltage using the voltage threshold.
The method according to claim 2 or 3, characterized in that, during the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold corresponding to the next charging stage, the The current threshold performs constant current charging of the battery, including:

During the constant voltage charging process, if it is determined that the current requested current value of the battery is less than the current threshold and the duration exceeds the second time period, the battery is charged with a constant current using the current threshold.
The method of claim 2 or 3, wherein the constant voltage charging of the battery at the voltage threshold includes:

By adjusting the current requested current value of the battery, the maximum cell voltage of the battery is controlled to be in a preset voltage interval, and the preset voltage interval is obtained by the voltage threshold of the current stage.
The method of claim 2 or 4, wherein performing constant current charging on the battery at the current threshold includes:

Based on the current battery status parameters of the battery, the requested current value of the battery is controlled to be within a preset current interval, and the preset current interval is obtained from the current threshold of the current stage.
The method of claim 2, wherein after performing constant current charging of the battery at the current threshold, it further includes:

If it is determined that the current maximum cell voltage of the battery is greater than or equal to the voltage threshold corresponding to the last charging stage and exceeds the third time period, charging is determined to be completed. The last charging stage corresponds to the maximum remaining power value in each charging stage. charging stage.
The method of claim 1, wherein determining the current charging stage corresponding to the current battery status parameter includes:

During the charging process of the battery, the current battery status parameters of the battery are collected in real time. The battery status parameters include battery core temperature value, remaining power value and voltage value;

Based on the cell temperature value, remaining power value and voltage value of the battery, the current charging stage corresponding to the current battery state is determined.
The method according to claim 1 or 8, characterized in that, before determining the current charging stage corresponding to the current battery status parameter, it further includes:

When it is detected that the electrical device where the battery is located is connected to the charging device, obtain the maximum output current value of the charging device;

Calculate the initial current value of the battery based on the current battery status parameters of the battery;

When it is determined that the initial current value is less than or equal to the maximum output charging current value, the battery is charged with the initial current value, and an initial charging stage corresponding to the initial current value is determined.
The method of claim 9, wherein after calculating the initial current value of the battery, it further includes:

When it is determined that the initial current value is greater than the maximum output current value, the battery is charged with the maximum output current value, and an initial charging stage corresponding to the maximum output charging current value is determined.
A battery charging device, characterized by including:

a determining module configured to determine the current charging stage corresponding to the current battery status parameter during the staged charging process of the battery;

The charging module is configured to alternately perform constant voltage charging or constant current charging on the battery based on the current battery status parameter, the current threshold and the voltage threshold corresponding to the current charging stage.
An electrical device, characterized in that it includes:

memory for storing executable instructions; and,

A processor, configured to execute the executable instructions with the memory to complete the operations of the battery charging method according to any one of claims 1-10.
A computer-readable storage medium used to store computer-readable instructions, characterized in that when the instructions are executed, the operations of the battery charging method in any one of claims 1-10 are performed.