A power battery attenuation control method and device, a vehicle

Abstract

The present application provides a power battery attenuation control method and device, and a vehicle, including: fitting the historical capacity retention rate of the power battery, and then taking the minimum capacity retention rate of all battery cells corresponding to the fitting result as the fitted capacity retention rate of the power battery, and determining the target parameter for adjusting the upper limit of the charging current according to the fitted capacity retention rate; then comparing the actual charging time of the power battery with the standard charging time; adjusting the target parameter when the actual charging time is not equal to the standard charging time; not adjusting the target parameter when they are equal; finally sending the unadjusted target parameter or the adjusted target parameter to the vehicle terminal, so that the vehicle terminal performs attenuation control on the power battery. The present application can effectively avoid overcharging and overdischarging of the power battery, prevent the rapid attenuation of the power battery, and the present application can also realize the rapid correction of the charging and discharging strategy of the vehicle end by combining with the cloud server.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a power battery attenuation control method and device, and a vehicle. Background Art

[0002] With the popularity of new energy vehicles and users' increasing requirements for new energy vehicles, in order to solve users' anxiety about the mileage and charging time of new energy vehicles, the current solution is to make the power battery pack more energy and the charging time shorter. The high energy of the power battery pack means that each battery pack needs more cells, and the short charging time requires a higher charging power. High-power charging will accelerate the aging of lithium batteries and affect the user experience.

[0003] When lithium battery manufacturers design power battery packs, the charging power will be adjusted as the battery ages. Usually, the charging power is strongly related to the battery's state of health (SOH). The onboard battery management system (BMS) will calculate the vehicle's current SOH value, but due to hardware limitations, the vehicle cannot store a large amount of data. At the same time, more and more power batteries are currently using fast charging. In the fast charging state, the SOH value cannot be accurately estimated using traditional ampere-hour integration, resulting in the battery actually decaying, but the charging power is not adjusted in time, thereby increasing the battery's charge and discharge power in disguise, accelerating the battery's aging.

[0004] Although the existing document CN115101836A discloses a cloud-integrated battery system management method and device, the solution focuses on solving the inconsistency problem of power batteries by changing the balancing strategy, and does not reversely feed back the results to the vehicle end for life control. In addition, although the existing document CN117452262A discloses a battery pack life evaluation method, evaluation device and test equipment, the document optimizes the battery pack structure design in combination with the heat dissipation design of different batteries in the battery pack, thereby extending the battery pack life, and does not disclose how to control the attenuation of the power battery. At the same time, although the existing document CN117805628A discloses a battery state quantitative evaluation method based on equivalent circuit parameters, the document only performs parameter identification based on a mixed power pulse test, explores the impact of the charging rate on parameter changes, and does not disclose how to control the attenuation of the power battery. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a power battery attenuation control method and device, and a vehicle, so as to solve the problem of how to control the attenuation of a power battery.

[0006] To achieve the above objectives and other related objectives, the present application provides a power battery attenuation control method, which is applied in the cloud and includes the following steps:

[0007] Determining a target parameter for adjusting an upper limit value of a charging current according to the fitted capacity retention rate;

[0008] comparing the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, adjusting the target parameter; when the actual charging time is equal to the standard charging time, not adjusting the target parameter;

[0009] The unadjusted target parameter or the adjusted target parameter is sent to the vehicle-mounted terminal, so that the vehicle-mounted terminal performs attenuation control on the power battery.

[0010] In one embodiment of the present application, the process of obtaining the fitted capacity retention rate includes:

[0011] Reading a charging state from charging data of a power battery, and identifying a charging condition of the power battery based on the charging state, wherein the charging condition includes: a fast charging condition and a slow charging condition;

[0012] Calculating the charging capacity of the power battery at each charging according to the identified charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging;

[0013] The minimum capacity retention rate among all battery cells corresponding to each calculation result is used as the calculated capacity retention rate of the power battery;

[0014] Associating each calculated capacity retention rate in history to obtain a historical capacity retention rate of the power battery;

[0015] The historical capacity retention rate of the power battery is fitted to obtain the capacity retention rate of all battery cells in the power battery; and the minimum capacity retention rate of all battery cells corresponding to the fitting result is used as the fitted capacity retention rate of the power battery.

[0016] In one embodiment of the present application, the process of calculating the charging capacity of the power battery at each charging according to the slow charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes:

[0017] Reading the charging current, the initial state of charge and the final state of charge from the charging data;

[0018] The charging current is integrated to calculate the charging capacity of the power battery at each charging under the slow charging condition, and the formula is: Q=∫I dt; where I represents the charging current, Q represents the charging capacity of the power battery at each charging under the slow charging condition, and t represents the actual charging time;

[0019] Based on the charging capacity of the power battery at each charging, the rated capacity of the battery cell, the initial state of charge and the final state of charge of the power battery, the capacity retention rate of the battery cell in the power battery after each charging is calculated as follows:

[0020]

[0021] Wherein, δQ represents the capacity retention rate of the battery cell in the power battery;

[0022] Q0 represents the rated capacity of the battery cell;

[0023] SOC1 indicates the initial state of charge;

[0024] SOC0 indicates the state of charge at the end of charging.

[0025] In one embodiment of the present application, the process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes:

[0026] A constant current segment is intercepted from the charging data segment under the fast charging condition, and the charging capacity of the constant current segment is calculated by current integration, which is recorded as Q1; and the average charging current at this time is recorded as

[0027] Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, denoted as and extracting the charging initial voltage V0 and the charging end voltage V1 of each battery cell in the constant current segment;

[0028] Generates the average charging current by pre- or real-time standard voltage-capacity curve Average or median temperature The voltage-capacity curve under is recorded as the target curve;

[0029] Based on the target curve, the initial charging voltage V0 and the charging end voltage V1 of each battery cell in the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0 and the charging capacity Q3 corresponding to the charging end voltage V1 are calculated respectively; and according to the calculated charging capacity Q1 of the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0, and the charging capacity Q3 corresponding to the charging end voltage V1, the capacity retention rate of the battery cell in the power battery after each charging is calculated.

[0030] In one embodiment of the present application, the capacity retention rate of the battery cell in the power battery after each charging is calculated based on the calculated charging capacity Q1 of the constant current segment, the charging capacity Q2 corresponding to the charging initial voltage V0, and the charging capacity Q3 corresponding to the charging end voltage V1, and the capacity retention rate of the battery cell in the power battery after each charging is calculated as follows:

[0031]

[0032] Wherein, δQ represents the capacity retention rate of the battery cell in the power battery.

[0033] In one embodiment of the present application, the process of generating a standard voltage-capacity curve includes:

[0034] Get the same new battery cell as the power battery and set the corresponding charging temperature range T a ~T b Divide into n parts, denoted as [T1, T2, ..., T n ]; and set the corresponding maximum charging rate value to C, and divide the charging rate into m parts, recorded as [C1, C2, ..., C m ];

[0035] Characterization tests are performed on different combinations of temperature and charge rate to obtain voltage-capacity curves of the new battery cell at different temperatures and charge rates as the standard voltage-capacity curve.

[0036] In one embodiment of the present application, when the actual charging time is not equal to the standard charging time, the process of adjusting the target parameter includes:

[0037] When the actual charging time is greater than the standard charging time, increasing the target parameter;

[0038] When the actual charging time is less than the standard charging time, the target parameter is adjusted to be smaller.

[0039] In one embodiment of the present application, the process of determining a target parameter for adjusting the upper limit value of the charging current according to the fitted capacity retention rate includes: using the fitted capacity retention rate as the target parameter.

[0040] The present application also provides a power battery attenuation control method, which is applied to a vehicle-mounted terminal, and the method comprises the following steps:

[0041] Receiving unadjusted target parameters or adjusted target parameters sent by the cloud;

[0042] Sending the unadjusted target parameter or the adjusted target parameter as a charging control signal to a vehicle controller, and forwarding the charging control signal to an onboard battery management system through the vehicle controller;

[0043] The vehicle-mounted battery management system multiplies the unadjusted target parameter or the adjusted target parameter by the initial current of the power battery when it leaves the factory to obtain an adjusted upper limit value of the charging current;

[0044] The charging process of the power battery is executed according to the adjusted upper limit value of the charging current to perform attenuation control on the power battery.

[0045] The present application also provides a power battery attenuation control device, which is applied to the cloud, and the device includes:

[0046] A target parameter module, used to determine a target parameter for adjusting an upper limit value of a charging current according to a fitted capacity retention rate;

[0047] a parameter adjustment module, used for comparing the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, adjusting the target parameter; when the actual charging time is equal to the standard charging time, not adjusting the target parameter;

[0048] The parameter sending module is used to send the unadjusted target parameter or the adjusted target parameter to the vehicle terminal so that the vehicle terminal can perform attenuation control on the power battery.

[0049] The present application also provides a power battery attenuation control device, which is applied to a vehicle-mounted terminal, and the device includes:

[0050] A parameter receiving module, used to receive unadjusted target parameters or adjusted target parameters sent by the cloud;

[0051] A battery attenuation control module is used to send an unadjusted target parameter or an adjusted target parameter as a charging control signal to a vehicle controller, and forward the charging control signal to a vehicle battery management system through the vehicle controller; and, through the vehicle battery management system, multiply the unadjusted target parameter or the adjusted target parameter with the initial current of the power battery at the time of leaving the factory to obtain an adjusted upper limit value of the charging current; and, execute the charging process of the power battery according to the adjusted upper limit value of the charging current to perform attenuation control on the power battery.

[0052] The present application also provides a vehicle, which includes the power battery attenuation control device as described above.

[0053] As described above, the present application provides a power battery attenuation control method and device, and a vehicle, which have the following beneficial effects:

[0054] The present application obtains the capacity retention rate of all battery cells in the power battery by fitting the historical capacity retention rate of the power battery; then the minimum capacity retention rate among all battery cells corresponding to the fitting result is used as the fitted capacity retention rate of the power battery, and the target parameter for adjusting the upper limit value of the charging current is determined according to the fitted capacity retention rate; then the actual charging time of the power battery is compared with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted; finally, the unadjusted target parameter or the adjusted target parameter is sent to the vehicle terminal, so that the vehicle terminal performs attenuation control on the power battery. It can be seen from this that the present application is fitted with the capacity retention rate estimated historically, eliminating the situation where huge deviations occur in accidental estimates, and obtaining the current capacity retention rate; then a parameter is set according to the current capacity retention rate, and based on the comparison result of the actual charging time and the standard charging time, it is determined whether the original set parameters need to be changed, thereby effectively avoiding overcharging and over-discharging of the power battery and preventing the rapid attenuation of the power battery, and the present application can also be combined with a cloud server to quickly correct the charging and discharging strategy on the vehicle side. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic diagram of an exemplary system architecture for applying the technical solutions in one or more embodiments of the present application;

[0056] Figure 2 A schematic diagram of a flow chart of a power battery attenuation control method provided in an embodiment of the present application;

[0057] Figure 3 A schematic flow chart of a power battery attenuation control method provided in another embodiment of the present application;

[0058] Figure 4 A schematic flow chart of a power battery attenuation control method provided in another embodiment of the present application;

[0059] Figure 5 A schematic diagram of the hardware structure of a power battery attenuation control device provided in an embodiment of the present application;

[0060] Figure 6 A schematic diagram of the hardware structure of a power battery attenuation control device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0061] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0062] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner, and therefore the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0063] Figure 1 A schematic diagram of an exemplary system architecture to which the technical solution in one or more embodiments of the present application can be applied is shown. Figure 1 As shown, the system architecture 100 may include a terminal device 110, a network 120, and a server 130. The terminal device 110 may include various electronic devices such as a smart phone, a tablet computer, a laptop computer, and a desktop computer. The server 130 may be an independent physical server, or a server cluster or a distributed system composed of multiple physical servers, or a cloud server providing cloud computing services. The network 120 may be a communication medium of various connection types that can provide a communication link between the terminal device 110 and the server 130, such as a wired communication link or a wireless communication link.

[0064] According to the implementation requirements, the system architecture in the embodiment of the present application can have any number of terminal devices, networks and servers. For example, the server 130 can be a server group composed of multiple server devices. In addition, the technical solution provided in the embodiment of the present application can be applied to the terminal device 110, can also be applied to the server 130, or can be implemented by the terminal device 110 and the server 130 together, and the present application does not make any special restrictions on this.

[0065] In one embodiment of the present application, the terminal device 110 or the server 130 of the present application can fit the historical capacity retention rate of the power battery to obtain the capacity retention rate of all battery cells in the power battery; then the minimum capacity retention rate of all battery cells corresponding to the fitting result is used as the fitted capacity retention rate of the power battery, and the target parameter for adjusting the upper limit value of the charging current is determined according to the fitted capacity retention rate; then the actual charging time of the power battery is compared with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted; finally, the unadjusted target parameter or the adjusted target parameter is sent to the vehicle terminal, so that the vehicle terminal performs attenuation control on the power battery. Among them, the historical capacity retention rate of the power battery is obtained based on the charging data of the power battery, and the power battery includes at least one battery cell. By using the terminal device 110 or the server 130 to execute the power battery attenuation control method, the capacity retention rate estimated historically can be combined for fitting, and the current capacity retention rate can be obtained by eliminating the situation where a huge deviation occurs in the accidental estimation; then a parameter is set according to the current capacity retention rate, and based on the comparison result between the actual charging time and the standard charging time, it is determined whether the originally set parameter needs to be changed, thereby effectively avoiding overcharging and over-discharging of the power battery, preventing the rapid attenuation of the power battery, and by combining with the cloud server, the charging and discharging strategy of the vehicle can be quickly corrected.

[0066] The above section introduces the contents of an exemplary device architecture that applies the technical solution of the present application. Next, the power battery attenuation control method of the present application will be introduced.

[0067] Figure 2 1 shows a schematic flow chart of a power battery attenuation control method provided by an embodiment of the present application. Specifically, in an exemplary embodiment, Figure 2 As shown, this embodiment provides a power battery attenuation control method, the method comprising the following steps:

[0068] S210, fitting the historical capacity retention rate of the power battery to obtain the capacity retention rate of all battery cells in the power battery; wherein the historical capacity retention rate of the power battery is obtained based on the charging data of the power battery, and the power battery includes at least one battery cell. As an example, in this embodiment or other embodiments, the charging data of the power battery can be obtained based on vehicle data, and the vehicle data includes but is not limited to charging time, charging state, cumulative mileage, battery cell voltage, current, battery probe temperature, SOC (State Of Charge, SOC for short) and other data. At the same time, when the charging data is obtained through vehicle data in this embodiment, the selected data can also be cleaned, including clearing invalid data, missing data completion and normalization, etc. In this embodiment or other embodiments, the power battery can be set in a target vehicle determined in advance or in real time, for example, the power battery can be set in a new energy test vehicle, or in a new energy market vehicle. In this embodiment or other embodiments, the capacity retention rate can also be represented by SOH, which will not be described in detail in this embodiment.

[0069] S220, taking the minimum capacity retention rate of all battery cells corresponding to the fitting result as the fitted capacity retention rate of the power battery, and determining the target parameter for adjusting the upper limit value of the charging current according to the fitted capacity retention rate. The target parameter includes but is not limited to the charging coefficient and the discharging coefficient. As an example, in this embodiment or other embodiments, the target parameter can be a value greater than 0 and less than or equal to 1.

[0070] S230, compare the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, adjust the target parameter; when the actual charging time is equal to the standard charging time, do not adjust the target parameter. As an example, in this embodiment or other embodiments, when adjusting the target parameter, this embodiment can increase the target parameter when the actual charging time is greater than the standard charging time; when the actual charging time is less than the standard charging time, reduce the target parameter. In this embodiment or other embodiments, when adjusting the target parameter, this embodiment can also adjust the value of the target parameter based on experience so that the actual charging time is not greater than the maximum charging time acceptable to the user, so as to avoid adjusting the parameters causing the actual charging time to be too long, which is unacceptable to the user.

[0071] S240: Send the unadjusted target parameter or the adjusted target parameter to the vehicle terminal, so that the vehicle terminal performs attenuation control on the power battery.

[0072] It can be seen that this embodiment combines the capacity retention rate estimated historically for fitting, eliminates the situation where accidental estimation has huge deviations, and obtains the current capacity retention rate; then sets a parameter according to the current capacity retention rate, and determines whether the originally set parameter needs to be changed based on the comparison result between the actual charging time and the standard charging time, thereby effectively avoiding overcharging and over-discharging of the power battery and preventing the rapid attenuation of the power battery.

[0073] According to the above records, in an exemplary embodiment, the process of attenuation control of the power battery by the vehicle terminal includes: receiving the unadjusted target parameters or adjusted target parameters sent from the cloud; sending the unadjusted target parameters or adjusted target parameters as charging control signals to the vehicle controller, and forwarding the charging control signals to the vehicle battery management system through the vehicle controller; multiplying the unadjusted target parameters or adjusted target parameters by the initial current of the power battery at the time of leaving the factory through the vehicle battery management system to obtain the adjusted upper limit of the charging current; executing the charging process of the power battery according to the adjusted upper limit of the charging current to perform attenuation control on the power battery. As an example, this embodiment can modify the charging and discharging strategy of the vehicle end by combining with the cloud server. Specifically, the fitted capacity retention rate is taken as the target parameter, denoted as a, and the parameter a is sent to the vehicle-side vehicle control domain (Tbox, VCU) in the form of a signal through the cloud server, and the vehicle control domain then forwards the signal to the on-board BMS. The on-board BMS multiplies the basic current of the power battery when it leaves the factory by the parameter a based on the received parameter a to obtain the adjusted upper limit of the charging current, and then the on-board BMS adjusts the charging and discharging strategy, and executes the charging process of the power battery according to the adjusted upper limit of the charging current. In addition, the on-board BMS can also feed back the adjusted parameter a1 to the cloud server for parameter update. It can be seen from this that this embodiment adjusts the battery charging and discharging strategy. After adjusting the charging and discharging strategy, the data under the new strategy is uploaded to the cloud server to re-evaluate the battery capacity retention rate, and the parameter a is continuously updated according to the decay speed of the battery, so as to effectively control the abnormal decay of the power battery life.

[0074] According to the above records, in an exemplary embodiment, the process of obtaining the historical capacity retention rate of a power battery based on the charging data of the power battery includes: reading the charging status from the charging data of the power battery, and identifying the charging condition of the power battery based on the charging status, the charging condition including: fast charging condition and slow charging condition; calculating the charging capacity of the power battery at each charging according to the identified charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging; taking the minimum capacity retention rate of all battery cells corresponding to each calculation result as the calculated capacity retention rate of the power battery each time; and associating the historical calculated capacity retention rates each time to obtain the historical capacity retention rate of the power battery.

[0075] According to the above records, in an exemplary embodiment, the process of calculating the charging capacity of the power battery at each charging according to the slow charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes: reading the charging current, the initial state of charge and the state of charge at the end of charging from the charging data; integrating the charging current to calculate the charging capacity of the power battery at each charging under the slow charging condition, and having: Q=∫I dt; wherein I represents the charging current, Q represents the charging capacity of the power battery at each charging under the slow charging condition, and t represents the actual charging time; based on the charging capacity of the power battery at each charging, the rated capacity of the battery cell, the initial state of charge and the state of charge at the end of charging, the capacity retention rate of the battery cell in the power battery after each charging is calculated, and having:

[0076]

[0077] In the formula, δQ represents the capacity retention rate of the battery cell in the power battery; Q0 ​​represents the rated capacity of the battery cell; SOC1 represents the initial state of charge; SOC0 represents the final state of charge. As an example, this embodiment can set SOC1-SOC0≥50%.

[0078] According to the above records, in an exemplary embodiment, the process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes: intercepting a constant current segment from the charging data segment under the fast charging condition, and calculating the charging capacity of the constant current segment by current integration, which is recorded as Q1; and recording the average charging current at this time as Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, denoted as And extract the charging initial voltage V0 and charging end voltage V1 of each battery cell in the constant current segment; generate the average charging current through the standard voltage-capacity curve obtained in advance or in real time Average or median temperature The voltage-capacity curve under the constant current segment is recorded as the target curve; based on the target curve, the initial charging voltage V0 and the charging end voltage V1 of each battery cell in the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0 and the charging capacity Q3 corresponding to the charging end voltage V1 are calculated respectively; and according to the calculated charging capacity Q1 of the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0, and the charging capacity Q3 corresponding to the charging end voltage V1, the capacity retention rate of the battery cell in the power battery after each charging is calculated. Specifically, in this embodiment, according to the calculated charging capacity Q1 of the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0, and the charging capacity Q3 corresponding to the charging end voltage V1, the capacity retention rate of the battery cell in the power battery after each charging is calculated, and there is: Wherein, δQ represents the capacity retention rate of the battery cell in the power battery.

[0079] According to the above records, in an exemplary embodiment, the process of generating a standard voltage-capacity curve includes: obtaining a new battery cell of the same type of power battery and setting the corresponding charging temperature range T a ~T b Divide into n parts, denoted as [T1, T2, ..., T n ]; and set the corresponding maximum charging rate value to C, and divide the charging rate into m parts, recorded as [C1, C2, ..., C m ]; After characterization tests were carried out on different combinations of temperature and charge rate, the voltage-capacity curves of the new battery cells at different temperatures and charge rates were obtained as standard voltage-capacity curves.

[0080] In another exemplary embodiment of the present application, Figure 3 As shown, this embodiment also provides a power battery attenuation control method, comprising the following steps:

[0081] Step 1: Collect vehicle data, which includes time, charging status, cumulative mileage, battery cell voltage, current, battery probe temperature, SOC and other characteristics, and perform data cleaning on the selected data, including removing invalid data, completing missing data and normalizing it.

[0082] Step 2: Calculate the capacity of the power battery each time it is charged by current integration, Q = ∫I dt, and then calculate the capacity retention rate after each charge. Different methods are used to calculate the capacity retention rate for fast charging and slow charging conditions of the power battery.

[0083] Step 3: Capacity retention rate for slow charging conditions Wherein Q is the charging capacity, Q0 is the rated capacity of the battery, SOC1 and SOC0 represent the charging end SOC and the charging initial SOC respectively, and SOC1-SOC0≥50%.

[0084] Step 4: For fast charging conditions, the capacity retention rate is calculated as follows:

[0085] ① Carry out characterization test on the new single cell of the same power battery, and divide the corresponding temperature range of -40℃~40℃ into 9 equal parts of 10℃, namely [T1, T2,..., T9]. Set the maximum charge rate to 4C, and divide the charge rate into 8 parts of 0.5C [C1, C2,..., C8]. Carry out characterization test on the battery with different combinations of temperature T and charge rate C. Obtain the voltage-capacity curve of the cell at different temperatures and charge rates.

[0086] ②Intercept the constant current segment in the fast charging segment uploaded to the cloud, and use the current integral to calculate the charging capacity Q1 of the constant current segment. The average charging current at this time is Calculate the average temperature or median temperature of the charging segment Extract the charging initial voltage V0 and the end voltage V1 of each cell in the power battery.

[0087] ③Use linear interpolation method to calculate the and Voltage-capacity curve under the conditions of .

[0088] ④ Using the charge initial voltage V0 and end voltage V1 extracted in step ②, in the voltage-capacity curve calculated in step ③, use the interpolation method to calculate the capacity Q2 corresponding to the initial voltage and the capacity Q3 corresponding to the charge end voltage. Capacity retention rate

[0089] Step 5: Perform a linear fit on the capacity retention rates calculated each time in history to estimate the current capacity retention rate. Take the minimum capacity retention rate of all battery cells as the capacity retention rate of the entire pack;

[0090] Step 6, calculate the actual charging time t each time. Under the same charging temperature, charging start voltage and charging end voltage, the charging time of a new battery is t0. The standard charging time of a new battery is calibrated by the standard charging time curve of a new battery.

[0091] Step 7: The cloud server sets a parameter a according to the currently estimated capacity retention rate, and the parameter a is used to lower the upper limit of the charging current.

[0092] Step 8, set a as a = δQ, and the cloud server sends the parameter a to the vehicle's vehicle control domain (Tbox, VCU) via a signal. The vehicle control domain then forwards the signal to the in-vehicle BMS.

[0093] Step 9, the in-vehicle BMS multiplies the base current at the time of the power battery's factory by the parameter a according to the received signal a.

[0094] Step 10, after adjusting the charge and discharge strategy, the data under the new strategy is uploaded to the cloud for re-evaluating the capacity retention rate of the battery. The parameter a is continuously updated according to the attenuation rate of the battery to effectively control the abnormal attenuation of the power battery's life.

[0095] Step 11, after updating the parameter a, the charging time t calculated in Step 6, and the charging time of a brand-new battery under the same conditions is t0. When t > t0, increase the parameter a and re-send it to the in-vehicle BMS; when t < t0, decrease the parameter a and re-send it to the in-vehicle BMS; when t and t0 are close, the parameter a at this time is the best. According to experience, when adjusting the value of the parameter a, t should not be greater than the maximum charging time acceptable to the user to avoid the charging time being too long due to parameter adjustment and the user being unable to accept it. As an example, in this embodiment or other embodiments, when t and t0 are close, it can be defaulted that t = t0; or the difference between t and t0 is within the error range and can be ignored.

[0096] It can be seen that in this embodiment, by collecting vehicle-end data, uploading it to the cloud server, extracting the charging segment according to the uploaded data, estimating the historical capacity retention rate of the power battery, and fitting it in combination with the historically estimated capacity retention rate, the situation of huge deviations in accidental estimation is excluded, and the current capacity retention rate is obtained. According to the current capacity retention rate value, a charging coefficient a is set, and the coefficient a is sent to the vehicle end through the cloud server. The in-vehicle BMS multiplies the original fast-charging rate by the coefficient a in the fast-charging strategy. Compared with the existing solution that uses the data uploaded from the vehicle end to the cloud for life estimation and does not feedback the result to the vehicle end for life control. This embodiment can effectively avoid the situation of overcharging and over-discharging of the battery, thereby preventing the rapid attenuation of the power battery, and combined with the cloud server, can quickly correct the strategy at the vehicle end.

[0097] In another exemplary embodiment of the present application, as Figure 4 shown, this embodiment also provides a method for controlling the attenuation of a power battery, which is applied to an in-vehicle terminal, and the method includes the following steps:

[0098] S410, receive the unadjusted target parameter or the adjusted target parameter sent from the cloud.

[0099] S420, sending the unadjusted target parameter or the adjusted target parameter as a charging control signal to the vehicle controller, and forwarding the charging control signal to the vehicle battery management system through the vehicle controller;

[0100] S430, multiplying the unadjusted target parameter or the adjusted target parameter by the initial current of the power battery when it leaves the factory through the vehicle battery management system to obtain an adjusted upper limit value of the charging current;

[0101] S440, executing a charging process of the power battery according to the adjusted upper limit value of the charging current to perform attenuation control on the power battery.

[0102] It should be noted that since the specific manner in which the vehicle-mounted terminal performs attenuation control on the power battery has been described in detail in some of the above embodiments, the technical functions and effects of the power battery attenuation control method provided in this embodiment can be referred to the above embodiments and will not be repeated here.

[0103] In summary, the present application provides a power battery attenuation control method, which obtains the capacity retention rate of all battery cells in the power battery by fitting the historical capacity retention rate of the power battery; then the minimum capacity retention rate among all battery cells corresponding to the fitting result is used as the fitted capacity retention rate of the power battery, and the target parameter for adjusting the upper limit value of the charging current is determined according to the fitted capacity retention rate; then the actual charging time of the power battery is compared with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted; finally, the unadjusted target parameter or the adjusted target parameter is sent to the vehicle terminal, so that the vehicle terminal performs attenuation control on the power battery. It can be seen that this method combines the capacity retention rate estimated historically for fitting, eliminates the situation where there are huge deviations in accidental estimation, and obtains the current capacity retention rate; then sets a parameter based on the current capacity retention rate, and determines whether the original set parameter needs to be changed based on the comparison result of the actual charging time and the standard charging time, so as to effectively avoid the situation of overcharging and over-discharging of the power battery and prevent the rapid attenuation of the power battery. In addition, this method can also be combined with the cloud server to quickly correct the charging and discharging strategy of the vehicle. Moreover, this method can use the historical data of the vehicle on the cloud and the large amount of computing resources of the cloud server to accurately estimate the real-time attenuation of the power battery, and send the calculation results to the vehicle. The vehicle dynamically adjusts the charge and discharge rate of the power battery according to the results sent from the cloud to prevent the accelerated attenuation of the power battery.

[0104] In another exemplary embodiment of the present application, Figure 5As shown, this embodiment also provides a power battery attenuation control device, including:

[0105] The capacity retention rate fitting module 510 is used to fit the historical capacity retention rate of the power battery, obtain the capacity retention rate of all battery cells in the power battery, and take the minimum capacity retention rate of all battery cells corresponding to the fitting result as the fitted capacity retention rate of the power battery; wherein, the historical capacity retention rate of the power battery is obtained based on the charging data of the power battery, and the power battery includes at least one battery cell. As an example, in this embodiment or other embodiments, the charging data of the power battery can be obtained based on vehicle data, and the vehicle data includes but is not limited to charging time, charging state, cumulative mileage, battery cell voltage, current, battery probe temperature, SOC (State Of Charge, SOC for short) and other data. At the same time, when the charging data is obtained through vehicle data in this embodiment, data cleaning can also be performed on the selected data, including clearing invalid data, completing missing data and normalizing, etc. In this embodiment or other embodiments, the power battery can be set in a target vehicle determined in advance or in real time, for example, the power battery can be set in a new energy test vehicle or a new energy market vehicle. In this embodiment or other embodiments, the capacity retention rate can also be represented by SOH, which will not be described in detail in this embodiment.

[0106] The target parameter module 520 is used to determine a target parameter for adjusting the upper limit value of the charging current according to the fitted capacity retention rate. As an example, in this embodiment or other embodiments, the target parameter may be a value greater than 0 and less than or equal to 1.

[0107] The parameter adjustment module 530 is used to compare the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted. As an example, in this embodiment or other embodiments, when the target parameter is adjusted, the present embodiment may increase the target parameter when the actual charging time is greater than the standard charging time; when the actual charging time is less than the standard charging time, the target parameter is reduced. In this embodiment or other embodiments, when the target parameter is adjusted, the present embodiment may also adjust the value of the target parameter based on experience so that the actual charging time is not greater than the maximum charging time acceptable to the user, thereby avoiding the adjustment of the parameter causing the actual charging time to be too long, which is unacceptable to the user.

[0108] The parameter sending module 540 is used to send the unadjusted target parameters or the adjusted target parameters to the vehicle terminal so that the vehicle terminal can perform attenuation control on the power battery.

[0109] It can be seen that this embodiment combines the capacity retention rate estimated historically for fitting, eliminates the situation where accidental estimation has huge deviations, and obtains the current capacity retention rate; then sets a parameter according to the current capacity retention rate, and determines whether the originally set parameter needs to be changed based on the comparison result between the actual charging time and the standard charging time, thereby effectively avoiding overcharging and over-discharging of the power battery and preventing the rapid attenuation of the power battery.

[0110] According to the above records, in an exemplary embodiment, the process of attenuation control of the power battery by the vehicle terminal includes: sending the unadjusted target parameter or the adjusted target parameter as a charging control signal to the vehicle controller, and forwarding the charging control signal to the vehicle battery management system through the vehicle controller; multiplying the unadjusted target parameter or the adjusted target parameter by the initial current of the power battery at the time of leaving the factory through the vehicle battery management system to obtain the adjusted upper limit of the charging current; executing the charging process of the power battery according to the adjusted upper limit of the charging current to perform attenuation control on the power battery. As an example, this embodiment can modify the charging and discharging strategy of the vehicle end by combining with the cloud server. Specifically, the fitting capacity retention rate is used as the target parameter, denoted as a, and the parameter a is sent to the vehicle end vehicle control domain (Tbox, VCU) in the form of a signal through the cloud server, and the vehicle control domain forwards the signal to the vehicle BMS, and the vehicle BMS multiplies the basic current of the power battery at the time of leaving the factory by the parameter a according to the received parameter a to obtain the adjusted upper limit of the charging current, and then the vehicle BMS adjusts the charging and discharging strategy and executes the charging process of the power battery according to the adjusted upper limit of the charging current. In addition, the vehicle-mounted BMS can also feed back the adjusted parameter a1 to the cloud server for parameter update. It can be seen that this embodiment adjusts the battery charging and discharging strategy. After adjusting the charging and discharging strategy, the data under the new strategy is uploaded to the cloud server to re-evaluate the battery capacity retention rate, and the parameter a is continuously updated according to the battery attenuation speed, so as to effectively control the abnormal attenuation of the power battery life.

[0111] According to the above records, in an exemplary embodiment, the process of obtaining the historical capacity retention rate of a power battery based on the charging data of the power battery includes: reading the charging status from the charging data of the power battery, and identifying the charging condition of the power battery based on the charging status, the charging condition including: fast charging condition and slow charging condition; calculating the charging capacity of the power battery at each charging according to the identified charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging; taking the minimum capacity retention rate of all battery cells corresponding to each calculation result as the calculated capacity retention rate of the power battery each time; and associating the historical calculated capacity retention rates each time to obtain the historical capacity retention rate of the power battery.

[0112] According to the above records, in an exemplary embodiment, the process of calculating the charging capacity of the power battery at each charging according to the slow charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes: reading the charging current, the initial state of charge and the state of charge at the end of charging from the charging data; integrating the charging current to calculate the charging capacity of the power battery at each charging under the slow charging condition, and having: Q=∫I dt; wherein I represents the charging current, Q represents the charging capacity of the power battery at each charging under the slow charging condition, and t represents the actual charging time; based on the charging capacity of the power battery at each charging, the rated capacity of the battery cell, the initial state of charge and the state of charge at the end of charging, the capacity retention rate of the battery cell in the power battery after each charging is calculated, and having:

[0113]

[0114] In the formula, δQ represents the capacity retention rate of the battery cell in the power battery; Q0 ​​represents the rated capacity of the battery cell; SOC1 represents the initial state of charge; SOC0 represents the final state of charge. As an example, this embodiment can set SOC1-SOC0≥50%.

[0115] According to the above records, in an exemplary embodiment, the process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes: intercepting a constant current segment from the charging data segment under the fast charging condition, and calculating the charging capacity of the constant current segment by current integration, which is recorded as Q1; and recording the average charging current at this time as Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, denoted as And extract the charging initial voltage V0 and charging end voltage V1 of each battery cell in the constant current segment; generate the average charging current through the standard voltage-capacity curve obtained in advance or in real time Average or median temperature The voltage-capacity curve under the constant current segment is recorded as the target curve; based on the target curve, the initial charging voltage V0 and the charging end voltage V1 of each battery cell in the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0 and the charging capacity Q3 corresponding to the charging end voltage V1 are calculated respectively; and according to the calculated charging capacity Q1 of the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0, and the charging capacity Q3 corresponding to the charging end voltage V1, the capacity retention rate of the battery cell in the power battery after each charging is calculated. Specifically, in this embodiment, according to the calculated charging capacity Q1 of the constant current segment, the charging capacity Q2 corresponding to the initial charging voltage V0, and the charging capacity Q3 corresponding to the charging end voltage V1, the capacity retention rate of the battery cell in the power battery after each charging is calculated, and there is: Wherein, δQ represents the capacity retention rate of the battery cell in the power battery.

[0116] According to the above records, in an exemplary embodiment, the process of generating a standard voltage-capacity curve includes: obtaining a new battery cell of the same type of power battery and setting the corresponding charging temperature range T a ~T b Divide into n parts, denoted as [T1, T2, ..., T n ]; and set the corresponding maximum charging rate to C, and divide the charging rate into m parts, denoted as] C1, C2, ..., C m ]; After characterization tests were carried out on different combinations of temperature and charge rate, the voltage-capacity curves of the new battery cells at different temperatures and charge rates were obtained as standard voltage-capacity curves.

[0117] In another exemplary embodiment of the present application, Figure 6 As shown, this embodiment also provides a power battery attenuation control device, which is applied to a vehicle-mounted terminal, and the device includes:

[0118] The parameter receiving module 610 is used to receive the unadjusted target parameters or the adjusted target parameters sent by the cloud;

[0119] The battery attenuation control module 620 is used to send the unadjusted target parameter or the adjusted target parameter as a charging control signal to the vehicle controller, and forward the charging control signal to the vehicle battery management system through the vehicle controller; and, through the vehicle battery management system, multiply the unadjusted target parameter or the adjusted target parameter with the initial current of the power battery at the time of leaving the factory to obtain an adjusted charging current upper limit value; and, execute the charging process of the power battery according to the adjusted charging current upper limit value to perform attenuation control on the power battery.

[0120] It should be noted that since the specific method of the vehicle-mounted terminal to perform attenuation control on the power battery has been described in detail in some of the above embodiments, the technical functions and effects of the power battery attenuation control device provided in this embodiment can be referred to the above embodiments and will not be repeated here.

[0121] In summary, the present application provides a power battery attenuation control device, which obtains the capacity retention rate of all battery cells in the power battery by fitting the historical capacity retention rate of the power battery; then the minimum capacity retention rate among all battery cells corresponding to the fitting result is used as the fitted capacity retention rate of the power battery, and the target parameter for adjusting the upper limit value of the charging current is determined according to the fitted capacity retention rate; then the actual charging time of the power battery is compared with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted; finally, the unadjusted target parameter or the adjusted target parameter is sent to the vehicle terminal, so that the vehicle terminal performs attenuation control on the power battery. It can be seen that this device is fitted with the capacity retention rate estimated historically, excluding the situation where there is a huge deviation in accidental estimation, and obtains the current capacity retention rate; then a parameter is set according to the current capacity retention rate, and based on the comparison result of the actual charging time and the standard charging time, it is determined whether the original set parameter needs to be changed, so as to effectively avoid the situation of overcharging and over-discharging of the power battery and prevent the rapid attenuation of the power battery. In addition, this device can also be combined with the cloud server to quickly correct the charging and discharging strategy of the vehicle. Moreover, this device can use the historical data of the vehicle on the cloud and the large amount of computing resources of the cloud server to accurately estimate the real-time attenuation of the power battery, and send the calculation results to the vehicle. The vehicle dynamically adjusts the charge and discharge rate of the power battery according to the results sent from the cloud to prevent the accelerated attenuation of the power battery.

[0122] It should be noted that the power battery attenuation control device provided in the above embodiment and the power battery attenuation control method provided in the above embodiment belong to the same concept, wherein the specific manner in which each module of the power battery attenuation control device performs operations has been described in detail in the above embodiment, and will not be repeated here. In actual applications, the power battery attenuation control device provided in the above embodiment can distribute the above functions to different functional modules as needed, that is, divide the internal structure of the power battery attenuation control device into different functional modules, and then implement all or part of the functions of the corresponding functional modules through the power battery attenuation control method described in the above embodiment, and this is not specifically limited here.

[0123] It should be noted that the above embodiments collect, store, use, process, transmit, provide, disclose, delete, etc. related data (such as vehicle data, charging data, etc.) with or with the consent of the user. For example, vehicle data and charging data are authorized with the knowledge and consent of the user; or are actively provided by the user after reading the relevant instructions, or are actively authorized / provided / uploaded by the user when using some or all of the functions described in the above embodiments, or are obtained through other methods / channels with or with the consent of the user.

[0124] In another exemplary embodiment of the present application, the embodiment further provides a vehicle, which includes a power battery attenuation control device as described in the above embodiment. It should be noted that since the specific manner in which the power battery attenuation control device performs operations has been described in detail in the embodiment, the technical functions and effects of the vehicle provided by this embodiment can be referred to the above embodiment, and will not be repeated here.

[0125] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A power battery attenuation control method, characterized in that: Applied to the cloud, the method comprises the following steps: Determining a target parameter for adjusting an upper limit value of a charging current according to the fitted capacity retention rate; comparing the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, adjusting the target parameter; when the actual charging time is equal to the standard charging time, not adjusting the target parameter; Sending the unadjusted target parameter or the adjusted target parameter to the vehicle terminal so that the vehicle terminal performs attenuation control on the power battery; The process of obtaining the fitted capacity retention rate includes: reading a charging state from charging data of a power battery, and identifying a charging condition of the power battery based on the charging state, wherein the charging condition includes a fast charging condition and a slow charging condition; and calculating a charging capacity of the power battery at each charging according to the identified charging condition, and calculating a capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging; and obtaining the fitted capacity retention rate based on the capacity retention rate of each battery cell in the power battery after each charging; The process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging comprises: extracting a constant current segment from the charging data segment under the fast charging condition, and calculating the charging capacity of the constant current segment by current integration, which is recorded as ; and, the average charging current at this time is recorded as ; Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, recorded as , and extract the initial charging voltage of each battery cell in the constant current segment and charging end voltage ; Generate the average charging current through the standard voltage-capacity curve obtained in advance or in real time , average temperature or median temperature The voltage-capacity curve under the constant current segment is recorded as the target curve; based on the target curve, the charging initial voltage of each battery cell in the constant current segment and charging end voltage , calculate the initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity ; and based on the calculated charging capacity of the constant current segment , initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity , calculate the capacity retention rate of the battery cells in the power battery after each charging.

2. The power battery attenuation control method according to claim 1, characterized in that: The process of obtaining the fitted capacity retention rate also includes: The minimum capacity retention rate among all battery cells corresponding to each calculation result is used as the calculated capacity retention rate of the power battery; Associating each calculated capacity retention rate in history to obtain a historical capacity retention rate of the power battery; The historical capacity retention rate of the power battery is fitted to obtain the capacity retention rate of all battery cells in the power battery; and the minimum capacity retention rate of all battery cells corresponding to the fitting result is used as the fitted capacity retention rate of the power battery.

3. The power battery attenuation control method according to claim 2, characterized in that: The process of calculating the charging capacity of the power battery at each charging according to the slow charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging comprises: Reading the charging current, the initial state of charge and the final state of charge from the charging data; The charging current is integrated to calculate the charging capacity of the power battery at each charging under the slow charging condition, and the result is: ; In the formula, Indicates the charging current, Indicates the charging capacity of the power battery at each charge under slow charging conditions. Indicates the actual charging time; Based on the charging capacity of the power battery at each charging, the rated capacity of the battery cell, the initial state of charge and the final state of charge of the power battery, the capacity retention rate of the battery cell in the power battery after each charging is calculated as follows: In the formula, Indicates the capacity retention rate of the battery cells in the power battery; Indicates the rated capacity of the battery cell; Indicates the initial state of charge; Indicates the charging state.

4. The power battery attenuation control method according to claim 2, characterized in that: Based on the calculated charging capacity of the constant current segment , initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity , calculate the capacity retention rate of the battery cells in the power battery after each charge, and there is: In the formula, Indicates the capacity retention rate of the battery cells in the power battery.

5. The power battery attenuation control method according to claim 2 or 4, characterized in that: The process of obtaining the standard voltage-capacity curve in advance or in real time includes: Get the same new battery cell as the power battery and set the corresponding charging temperature range Divide into n parts, denoted as ; and set the corresponding maximum charging rate to C, and divide the charging rate into m parts, recorded as ; Characterization tests are performed on different combinations of temperature and charge rate to obtain voltage-capacity curves of the new battery cell at different temperatures and charge rates as the standard voltage-capacity curve.

6. The power battery attenuation control method according to claim 1, characterized in that: When the actual charging time is not equal to the standard charging time, the process of adjusting the target parameter includes: When the actual charging time is greater than the standard charging time, increasing the target parameter; When the actual charging time is less than the standard charging time, the target parameter is adjusted to be smaller.

7. The power battery attenuation control method according to claim 1 or 6, characterized in that: The process of determining a target parameter for adjusting the upper limit value of the charging current according to the fitted capacity retention rate includes: using the fitted capacity retention rate as the target parameter.

8. A power battery attenuation control method, characterized in that: Applied to a vehicle-mounted terminal, the method comprises the following steps: Receiving unadjusted target parameters or adjusted target parameters sent by the cloud; Sending the unadjusted target parameter or the adjusted target parameter as a charging control signal to a vehicle controller, and forwarding the charging control signal to an onboard battery management system through the vehicle controller; The vehicle-mounted battery management system multiplies the unadjusted target parameter or the adjusted target parameter by the initial current of the power battery when it leaves the factory to obtain an adjusted upper limit value of the charging current; Executing a charging process of the power battery according to the adjusted upper limit value of the charging current to perform attenuation control on the power battery; The cloud determines a target parameter for adjusting the upper limit value of the charging current according to the fitted capacity retention rate, and compares the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted; The process of obtaining the fitted capacity retention rate in the cloud includes: reading the charging status from the charging data of the power battery, and identifying the charging condition of the power battery based on the charging status, the charging condition including: fast charging condition and slow charging condition; and, calculating the charging capacity of the power battery at each charging according to the identified charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging; obtaining the fitted capacity retention rate based on the capacity retention rate of each battery cell in the power battery after each charging; wherein, the process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes: intercepting a constant current segment from a charging data segment under the fast charging condition, and calculating the charging capacity of the constant current segment by current integration, recorded as ; and, the average charging current at this time is recorded as ; Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, recorded as , and extract the initial charging voltage of each battery cell in the constant current segment and charging end voltage ; Generate the average charging current through the standard voltage-capacity curve obtained in advance or in real time , average temperature or median temperature The voltage-capacity curve under the constant current segment is recorded as the target curve; based on the target curve, the charging initial voltage of each battery cell in the constant current segment and charging end voltage , calculate the initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity ; and based on the calculated charging capacity of the constant current segment , initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity , calculate the capacity retention rate of the battery cells in the power battery after each charging.

9. A power battery attenuation control device, characterized in that: Applied to the cloud, the device includes: A target parameter module, used to determine a target parameter for adjusting an upper limit value of a charging current according to a fitted capacity retention rate; a parameter adjustment module, used for comparing the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, adjusting the target parameter; when the actual charging time is equal to the standard charging time, not adjusting the target parameter; A parameter sending module, used for sending an unadjusted target parameter or an adjusted target parameter to a vehicle-mounted terminal, so that the vehicle-mounted terminal performs attenuation control on the power battery; The process of obtaining the fitted capacity retention rate on the cloud includes: reading a charging state from charging data of a power battery, and identifying a charging condition of the power battery based on the charging state, wherein the charging condition includes a fast charging condition and a slow charging condition; and calculating a charging capacity of the power battery at each charging according to the identified charging condition, and calculating a capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging; and obtaining the fitted capacity retention rate based on the capacity retention rate of each battery cell in the power battery after each charging; The process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging comprises: extracting a constant current segment from the charging data segment under the fast charging condition, and calculating the charging capacity of the constant current segment by current integration, which is recorded as ; and, the average charging current at this time is recorded as ; Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, recorded as , and extract the initial charging voltage of each battery cell in the constant current segment and charging end voltage ; Generate the average charging current through the standard voltage-capacity curve obtained in advance or in real time , average temperature or median temperature The voltage-capacity curve under the constant current segment is recorded as the target curve; based on the target curve, the charging initial voltage of each battery cell in the constant current segment and charging end voltage , calculate the initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity ; and based on the calculated charging capacity of the constant current segment , initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity , calculate the capacity retention rate of the battery cells in the power battery after each charging.

10. A power battery attenuation control device, characterized in that: Applied to a vehicle-mounted terminal, the device comprises: A parameter receiving module, used to receive unadjusted target parameters or adjusted target parameters sent by the cloud; A battery attenuation control module, configured to send an unadjusted target parameter or an adjusted target parameter as a charging control signal to a vehicle controller, and forward the charging control signal to an onboard battery management system through the vehicle controller; and to multiply the unadjusted target parameter or the adjusted target parameter by an initial current of the power battery at the time of leaving the factory through the onboard battery management system to obtain an adjusted upper limit value of the charging current; and, executing a charging process of the power battery according to the adjusted upper limit value of the charging current to perform attenuation control on the power battery; The cloud determines a target parameter for adjusting the upper limit value of the charging current according to the fitted capacity retention rate, and compares the actual charging time of the power battery with the standard charging time; when the actual charging time is not equal to the standard charging time, the target parameter is adjusted; when the actual charging time is equal to the standard charging time, the target parameter is not adjusted; The process of obtaining the fitted capacity retention rate in the cloud includes: reading the charging status from the charging data of the power battery, and identifying the charging condition of the power battery based on the charging status, the charging condition including: fast charging condition and slow charging condition; and, calculating the charging capacity of the power battery at each charging according to the identified charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging; obtaining the fitted capacity retention rate based on the capacity retention rate of each battery cell in the power battery after each charging; wherein, the process of calculating the charging capacity of the power battery at each charging according to the fast charging condition, and calculating the capacity retention rate of each battery cell in the power battery after each charging according to the charging capacity of the power battery at each charging includes: intercepting a constant current segment from a charging data segment under the fast charging condition, and calculating the charging capacity of the constant current segment by current integration, recorded as ; and, the average charging current at this time is recorded as ; Calculate the average temperature or median temperature of the charging data fragment under fast charging conditions, recorded as , and extract the initial charging voltage of each battery cell in the constant current segment and charging end voltage ; Generate the average charging current through the standard voltage-capacity curve obtained in advance or in real time , average temperature or median temperature The voltage-capacity curve under the constant current segment is recorded as the target curve; based on the target curve, the charging initial voltage of each battery cell in the constant current segment and charging end voltage , calculate the initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity ; and based on the calculated charging capacity of the constant current segment , initial charging voltage Corresponding charging capacity , charging end voltage Corresponding charging capacity , calculate the capacity retention rate of the battery cells in the power battery after each charging.

11. A vehicle, characterized in that: The vehicle includes the power battery attenuation control device as claimed in claim 10.

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