A battery charging method

Abstract

The present application provides a battery charging method. During the pre-charging process, the aging degree of the battery to be charged can be determined by obtaining the battery parameters of the battery to be charged, and then the corresponding charging scheme is determined according to the aging degree, so that batteries with different aging degrees can adopt different charging methods, which is beneficial to improving the safety of the battery during the charging process.

Description

Technical Field

[0001] The present application relates to the technical field of charging piles, and in particular to a battery charging method. Background Art

[0002] With the progress of the times, the number of new energy vehicles is increasing, and the power batteries in new energy vehicles need to be charged through charging piles when they need to be charged. As the power battery ages during use, the charging performance of the power battery will decrease after aging. In the prior art, the charging pile uses the same charging method whether charging a new power battery or charging an aged power battery. However, since the charging performance of power batteries with different degrees of aging are different, if a unified charging method is used, the safety of the charging process cannot be guaranteed. Summary of the invention

[0003] In view of this, an object of the present application is to provide a battery charging method to improve the safety of the battery during the charging process.

[0004] In view of the above problems, an embodiment of the present application provides a battery charging method, the method comprising a pre-charging process and a charging process, wherein the pre-charging process is used to determine a charging scheme for a battery to be charged, and the charging process is used to charge the battery to be charged. The method is applied to a charging pile, and the method comprises:

[0005] When the battery to be charged meets the charging condition, in the pre-charging process, the factory rated capacity Q1 of the battery to be charged, the number of charge and discharge times N of the battery to be charged, the aging coefficient A of the battery to be charged, the average operating temperature T of the battery to be charged and the average humidity H of the working environment of the battery to be charged, which are stored in the battery management system of the battery to be charged, are obtained;

[0006] The temperature influence coefficient is calculated by the following formula:

[0007] ;

[0008] Among them, α is the standard temperature sensitivity coefficient, Tref is the standard operating temperature;

[0009] The humidity influence coefficient is calculated by the following formula:

[0010] ;

[0011] Among them, γ is the standard humidity sensitivity coefficient, Standard operating humidity, is the upper limit humidity value of the humidity influence coefficient, is the lower limit humidity value of the humidity influence coefficient, n is the standard exponential factor, exp represents the exponential function, is the standard deviation of temperature effect;

[0012] The current total available capacity Q2 of the battery to be charged is calculated by the following formula:

[0013] ;

[0014] The battery capacity retention rate Y of the battery to be charged is calculated by the following formula;

[0015] ;

[0016] Determine an aging interval corresponding to the battery capacity retention rate Y, and use the aging degree corresponding to the aging interval as the aging degree of the battery to be charged;

[0017] According to the aging degree, determining corresponding charging parameters from a corresponding relationship table between aging degrees and charging parameters;

[0018] During the charging process, the battery to be charged is charged according to the charging parameters.

[0019] Optionally, the method further comprises:

[0020] When the battery to be charged is connected to the charging pile, determining the type of the battery to be charged according to the detected voltage of the battery to be charged;

[0021] When the type of the battery to be charged meets the charging type of the charging pile, the battery to be charged meets the charging condition.

[0022] Optionally, charging the battery to be charged according to the charging parameter includes:

[0023] According to the charging current in the charging parameter, the battery to be charged is charged with constant current, and the open circuit voltage of the battery to be charged during the charging process is detected;

[0024] When the open circuit voltage reaches the voltage set in the charging parameters, the battery to be charged is charged at a constant voltage according to the charging voltage and charging time in the charging parameters.

[0025] Optionally, when the aging degree is greater than or equal to the aging degree threshold, prompt information indicating the current aging degree of the battery to be charged is sent to a user paired with the battery to be charged.

[0026] Optionally, the method further comprises:

[0027] After charging is completed, the charging parameters in this charging process are sent to the battery management system, so that the battery management system updates the charging parameters in this charging process locally.

[0028] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0029] In the present application, the entire charging process includes a pre-charging process and a charging process. The pre-charging process is used to obtain the battery parameters of the battery to be charged, and the charging process is used to charge the battery to be charged. In the pre-charging process, the aging degree of the battery to be charged can be determined by obtaining the battery parameters of the battery to be charged, and then the corresponding charging scheme is determined according to the aging degree, so that batteries with different aging degrees can adopt different charging methods, which is beneficial to improve the safety of the battery during the charging process.

[0030] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of a battery charging method provided in this application. DETAILED DESCRIPTION

[0033] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0034] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0035] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0036] In new energy vehicles, power batteries are one of the most important components, and the safety of new energy vehicles is closely related to power batteries, that is, most of the fires in new energy vehicles are caused by power batteries, which will gradually age with the length of time they are used. In the prior art, batteries of any degree of aging use the same charging method, but for batteries with a higher degree of aging, their charging performance will decrease, for example, the internal resistance will increase. If the same charging method is used, the heat of batteries with a higher degree of aging will increase faster, causing safety problems.

[0037] In order to solve the above problems, the present application provides a battery charging method, wherein the entire charging process includes a pre-charging process and a charging process, wherein the pre-charging process is used to determine a charging scheme for a battery to be charged, and the charging process is used to charge the battery to be charged. During the pre-charging process, the aging degree of the battery to be charged can be determined by acquiring the battery parameters of the battery to be charged, and then the corresponding charging scheme is determined according to the aging degree, so that batteries with different aging degrees can adopt different charging methods, which is beneficial to improving the safety of the battery during the charging process.

[0038] It should be noted that the battery to be charged in the present application can be a power battery in a new energy vehicle, or other types of batteries charged using a charging pile, and the specific battery type is not specifically limited here.

[0039] Figure 1 A schematic flow chart of a battery charging method provided in the present application, the method comprising a pre-charging process and a charging process, wherein the pre-charging process is used to determine a charging scheme for a battery to be charged, and the charging process is used to charge the battery to be charged, and the method is applied to a charging pile, such as Figure 1 As shown, the method includes:

[0040] Step 101. When the battery to be charged meets the charging conditions, in the pre-charging process, the factory rated capacity Q1 of the battery to be charged, the number of charge and discharge times N of the battery to be charged, the aging coefficient A of the battery to be charged, the average operating temperature T of the battery to be charged and the average humidity H of the working environment of the battery to be charged, which are stored in the battery management system of the battery to be charged, are obtained.

[0041] Step 102: Calculate the temperature influence coefficient using the following formula:

[0042] ; (Formula 1)

[0043] Wherein, α is the standard temperature sensitivity coefficient, and Tref is the standard operating temperature.

[0044] Step 103, calculate the humidity influence coefficient by the following formula 2:

[0045] ; (Formula 2)

[0046] Among them, γ is the standard humidity sensitivity coefficient, Standard operating humidity, is the upper limit humidity value of the humidity influence coefficient, is the lower limit humidity value of the humidity influence coefficient, n is the standard exponential factor, exp represents the exponential function, is the standard deviation of the temperature effect.

[0047] Step 104: Calculate the current total available capacity Q2 of the battery to be charged by the following formula 3:

[0048] ; (Formula 3)

[0049] Step 105, calculating the battery capacity retention rate Y of the battery to be charged by the following formula 4;

[0050] ; (Formula 4)

[0051] Step 106: Determine the aging interval corresponding to the battery capacity retention rate Y, and use the aging degree corresponding to the aging interval as the aging degree of the battery to be charged.

[0052] Step 107: According to the aging degree, determine the corresponding charging parameter from a corresponding relationship table between the aging degree and the charging parameter.

[0053] Step 108: During the charging process, the battery to be charged is charged according to the charging parameters.

[0054] Specifically, in order to ensure the safety of the battery to be charged during the charging process, the entire charging process is divided into a pre-charging process and a charging process, wherein the pre-charging process is used to determine the charging plan for the battery to be charged, and the charging process is used to charge the battery to be charged. In order to determine the charging plan for the battery to be charged, it is necessary to determine the aging degree of the battery to be charged, and then determine the corresponding charging plan. Since the battery capacity retention rate will change after aging, and the change is positively correlated with the aging degree, the aging degree of the battery to be charged can be determined by calculating the battery capacity retention rate. After determining the aging degree of the battery to be charged, the charging plan for the battery to be charged is determined, and the charging plan includes: charging current and charging voltage, etc.

[0055] In order to manage the battery, a battery management system is usually set up for the battery, and the battery management system also has a certain storage capacity for storing relevant data of the battery, such as: factory time, battery model, rated voltage, etc. After the battery to be charged is connected to the charging pile, the charging pile can charge the battery to be charged. In order to ensure the safety of the battery to be charged during the charging process, a pre-charging process is set. During the pre-charging process, the required data can be obtained from the battery management system, such as: the factory rated capacity Q1 of the battery to be charged, the number of charge and discharge times N of the battery to be charged, the aging coefficient A of the battery to be charged, the average operating temperature T of the battery to be charged and the average humidity H of the working environment of the battery to be charged, wherein the average operating temperature can be calculated by the battery management system according to the operating temperature collected within a preset time, and the average humidity can be calculated by the battery management system according to the working environment humidity collected within a preset time, wherein the time corresponding to the data used in calculating the average operating temperature and the average humidity is the same, and the preset time can be calculated by month, by quarter, or of course, by year.

[0056] Since too high or too low temperature, as well as too humid or too dry environment, have a great influence on the attenuation of battery capacity, the charging pile can use the above data to calculate the temperature influence coefficient and the humidity influence coefficient after obtaining the above data, wherein the temperature influence coefficient is used to indicate the degree of influence of temperature on the attenuation of battery capacity, and the humidity influence coefficient is used to indicate the degree of influence of humidity on the attenuation of battery capacity. The standard temperature sensitivity coefficient used in calculating the temperature influence coefficient is a preset fixed value, and the standard operating temperature can be 25°C. The standard humidity sensitivity coefficient is determined by experimental data, and the standard humidity sensitivity coefficients corresponding to different types of batteries are different. In this application, the charging pile can be selected according to the type of battery to be charged. The standard operating humidity is the working humidity when the battery performance is optimal, and the battery capacity decays slowest at this humidity. The standard working humidity can also be selected by the charging pile according to the type of battery to be charged. The upper and lower humidity values ​​can be set according to the environment of the area where the charging pile is located, and the standard exponential factor can also be set according to the environment of the area where the charging pile is located. The standard deviation of the temperature effect is used to indicate the degree of influence of the temperature on the humidity influence coefficient. The standard deviation of the temperature effect can be determined experimentally for the standard deviation of the temperature effect corresponding to different types of batteries.

[0057] After obtaining the current total available capacity of the battery to be charged through the above content, the battery capacity retention rate can be calculated. The retention rate can reflect the aging degree of the battery. After obtaining the aging degree of the battery to be charged, the corresponding charging plan is determined to charge the battery to be charged. Since the charging plan is determined based on the aging degree of the battery to be charged, it is beneficial to ensure the safety of the battery to be charged during the charging process.

[0058] In one possible implementation, in order to obtain Figure 1 The parameters designed in the steps shown make the calculation results more accurate. Therefore, when the battery to be charged is connected to the charging pile, the type of the battery to be charged is determined according to the detected voltage of the battery to be charged. When the type of the battery to be charged meets the charging type of the charging pile, the battery to be charged meets the charging condition.

[0059] Specifically, when the battery to be charged is connected to the charging pile, the charging pile can detect the voltage of the battery to be charged. Since different voltages correspond to different battery types, the type of the battery to be charged connected to the charging pile can be determined by the voltage. When the type of the battery to be charged meets the charging type of the charging pile, the battery to be charged meets the charging condition, that is, the charging pile can only charge a specific type of battery. If the battery to be charged is of this specific type, the condition is met. This charging method can determine the degree of battery aging more accurately.

[0060] In a feasible implementation scheme, when executing step 108, the battery to be charged is first charged with a constant current according to the charging current in the charging parameters, and the open circuit voltage of the battery to be charged during the charging process is detected; when the open circuit voltage reaches the voltage set in the charging parameters, the battery to be charged is charged with a constant voltage according to the charging voltage and charging time in the charging parameters.

[0061] Specifically, at the beginning of charging, the battery voltage is low. At this time, charging with a constant current can ensure that the battery voltage rises steadily, while avoiding damage to the battery caused by excessive charging current. As charging progresses, the battery voltage gradually increases, but the charging current remains unchanged until the battery voltage reaches the preset voltage. At the end of the constant current charging stage, there will be a certain polarization phenomenon inside the battery, that is, the battery voltage contains a part of the polarization voltage. In order to eliminate this polarization effect and charge the battery to full capacity, it is necessary to enter the constant voltage charging stage. By gradually reducing the charging current, the degree of polarization inside the battery can be reduced, making the chemical reaction in the battery more uniform and eventually reaching a saturated state.

[0062] It should be noted that, in the constant voltage charging stage, the charging may also be terminated when the charging current is equal to 0.01 Q1.

[0063] In a feasible implementation manner, when the aging degree is greater than or equal to the aging degree threshold, prompt information indicating the current aging degree of the battery to be charged is sent to a user paired with the battery to be charged.

[0064] Specifically, the battery to be charged can be bound to the user terminal so that the battery to be charged and the user terminal are paired. When it is determined that the aging degree of the battery to be charged is greater than or equal to the aging degree threshold, it means that the aging degree of the battery to be charged is relatively serious. At this time, it is necessary to send a prompt information to the user to prompt the current aging degree of the battery to be charged. The prompt information includes: the level of aging degree, specific parameters of the aging degree, and whether the battery to be charged needs to be replaced.

[0065] It should be noted that when the battery to be charged is bound to the user terminal, the pairing can be completed by binding the user terminal to the new energy vehicle where the battery to be charged is located, or it can be completed by other means, which is not specifically limited here, and the specific prompt information can also be set according to actual needs. Specific content is not specifically limited here.

[0066] In a feasible implementation scheme, after charging is completed, the charging parameters of this charging process are sent to the battery management system, so that the battery management system updates the charging parameters of this charging process locally to provide relevant data for the next charging.

[0067] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application. They should all be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A battery charging method, characterized in that: The method includes a pre-charging process and a charging process, wherein the pre-charging process is used to determine a charging scheme for a battery to be charged, and the charging process is used to charge the battery to be charged. The method is applied to a charging pile, and the method includes: When the battery to be charged meets the charging condition, in the pre-charging process, the factory rated capacity Q1 of the battery to be charged, the number of charge and discharge times N of the battery to be charged, the aging coefficient A of the battery to be charged, the average operating temperature T of the battery to be charged and the average humidity H of the working environment of the battery to be charged, which are stored in the battery management system of the battery to be charged, are obtained; The temperature influence coefficient is calculated by the following formula: ； Among them, α is the standard temperature sensitivity coefficient, Tref is the standard operating temperature; The humidity influence coefficient is calculated by the following formula: ； Wherein, γ is the standard humidity sensitivity coefficient, Hopt is the standard working humidity, Hmax is the upper limit humidity value of the humidity influence coefficient, Hmin is the lower limit humidity value of the humidity influence coefficient, n is the standard exponential factor, exp represents the exponential function, is the standard deviation of temperature effect; The current total available capacity Q2 of the battery to be charged is calculated by the following formula: ； The battery capacity retention rate Y of the battery to be charged is calculated by the following formula; ； Determine an aging interval corresponding to the battery capacity retention rate Y, and use the aging degree corresponding to the aging interval as the aging degree of the battery to be charged; According to the aging degree, determining corresponding charging parameters from a corresponding relationship table between aging degrees and charging parameters; During the charging process, the battery to be charged is charged according to the charging parameters; When the aging degree is greater than or equal to the aging degree threshold, prompt information indicating the current aging degree of the battery to be charged is sent to a user paired with the battery to be charged.

2. The method according to claim 1, characterized in that The method further comprises: When the battery to be charged is connected to the charging pile, determining the type of the battery to be charged according to the detected voltage of the battery to be charged; When the type of the battery to be charged meets the charging type of the charging pile, the battery to be charged meets the charging condition.

3. The method according to claim 1, characterized in that The step of charging the battery to be charged according to the charging parameter comprises: According to the charging current in the charging parameter, the battery to be charged is charged with constant current, and the open circuit voltage of the battery to be charged during the charging process is detected; When the open circuit voltage reaches the voltage set in the charging parameters, the battery to be charged is charged at a constant voltage according to the charging voltage and charging time in the charging parameters.

4. The method according to claim 1, characterized in that The method further comprises: After charging is completed, the charging parameters in this charging process are sent to the battery management system, so that the battery management system updates the charging parameters in this charging process locally.

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