Method and device for determining capacity attenuation rate of power battery system

Abstract

The present invention provides a method and device for determining the capacity attenuation rate of a power battery system, relating to the technical field of batteries. The method includes: obtaining the historical charging data of the target power battery system; dividing the historical charging data into at least one charging process according to the charging time, the highest single cell voltage, and the driving mileage; determining the first charging process according to the proportion of each average charging information in all average charging information and the driving mileage; determining multiple charging processes with average charging information in the same interval range as the second charging process; and determining the capacity attenuation rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process. The solution of the present invention evaluates the capacity attenuation situation based on the usage conditions of electric vehicles, so as to judge whether there is an abnormality in the battery health state and identify battery risks in advance.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic devices, and particularly relates to a method and device for determining the capacity attenuation rate of a power battery system. Background Art

[0002] The safety issues of new energy vehicle power battery systems are becoming increasingly severe. Due to the complex battery chemical system, as the vehicle operates, the positive and negative electrode materials and diaphragms of the battery continuously age. Coupled with the influence of the external environment, extreme safety accidents may even occur. Therefore, the health status of the battery system throughout its life cycle has always been highly concerned.

[0003] Generally, the state of health (SOH) of a power battery is used to represent the health status of the battery. The SOH value is usually estimated by the battery management system by looking up a table based on the cumulative charge and discharge capacity of the battery. The table is usually formulated according to the cycle experiments of single cells in the laboratory. However, the health status of the power battery is affected by external factors such as long-term use temperature and current. There is a deviation between directly evaluating the health status of the power battery system with the SOH value estimated by the battery management system and the actual situation. In addition, in the operation data of new energy vehicles, the use conditions of full charge and full discharge are less, and there is a large difference from the cycle experiment conditions in the laboratory. At the same time, the existing operation data of the vehicle also cannot support some capacity estimation methods that require a static time. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a method and device for determining the capacity attenuation rate of a power battery system, so as to solve the problem that there is a deviation between the evaluation of the health status of the power battery system in the prior art and the actual situation.

[0005] To achieve the above purpose, the embodiments of the present invention provide a method for determining the capacity attenuation rate of a power battery system, including:

[0006] Obtain the historical charging data of the target power battery system; wherein, the historical charging data includes: a plurality of charging times and the corresponding maximum single cell voltage, charging current, maximum single cell temperature, and driving mileage at each charging time;

[0007] Divide the historical charging data into at least one charging process according to the charging time, the maximum single cell voltage, and the driving mileage;

[0008] Determine the first charging process according to the proportion of each average charging information in all average charging information and the driving mileage; wherein, the average charging information includes the average charging current and the average maximum single cell temperature of each charging process;

[0009] Determine multiple charging processes with the average charging information in the same interval range as the second charging process;

[0010] Determine the capacity attenuation rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and the multiple second driving mileages and the multiple second charging capacities corresponding to the second charging process.

[0011] Optionally, according to the charging time, the highest single cell voltage, and the driving mileage, divide the historical charging data into at least one charging process, including:

[0012] Divide the historical charging data that meets the following conditions into the same charging process:

[0013] The time difference between adjacent charging times is less than or equal to a preset duration;

[0014] The highest single cell voltage corresponding to each charging time is within a preset voltage range;

[0015] The driving mileage corresponding to each charging time is the same;

[0016] Wherein, the preset voltage range is from the platform voltage to the full charge voltage, or from the platform voltage to the sub-full charge voltage.

[0017] Optionally, after dividing the historical charging data into at least one charging process according to the charging time, the highest single cell voltage, and the driving mileage, further include:

[0018] Calculate the charging capacity of at least one of the charging processes respectively.

[0019] Optionally, calculating the charging capacity of at least one of the charging processes respectively includes:

[0020] Calculate the charging capacity according to the multiple charging times and the multiple charging currents in each charging process.

[0021] Optionally, before determining the first charging process according to the proportion of each average charging information in all the average charging information and the driving mileage, further include:

[0022] In each charging process, select a highest single cell voltage at intervals of a preset voltage as a reference voltage point;

[0023] Take the charging current and the highest single cell temperature corresponding to the reference voltage point as the segmented current and the segmented temperature respectively; calculate the average charging current and the average highest single cell temperature respectively according to the multiple segmented currents and the multiple segmented temperatures in each charging process.

[0024] Optionally, determining the first charging process according to the proportion of each average charging information in all the average charging information and the driving mileage includes:

[0025] Determine the charging process with the largest or second - largest ratio and a driving mileage greater than a preset mileage as the first charging process.

[0026] Optionally, before determining multiple charging processes with the same average charging information or satisfying a first linear relationship as the second charging process, it further includes:

[0027] Sort the multiple pieces of average charging information;

[0028] Select the smallest piece of average charging information as the starting - point information;

[0029] Determine multiple interval ranges according to the starting - point information and a preset interval length.

[0030] Optionally, determining the capacity attenuation rate of the target power - battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process includes:

[0031] Fit the first driving mileage and the first charging capacity, and multiple second driving mileages and multiple second charging capacities to obtain a target straight line for the attenuation of the charging capacity with the driving mileage;

[0032] Determine the capacity attenuation rate according to the slope of the target straight line.

[0033] Optionally, the method further includes:

[0034] Judge whether the capacity attenuation rate is abnormal according to a life - setting abnormal threshold.

[0035] Optionally, the method further includes:

[0036] Send a warning signal when the capacity attenuation rate is abnormal.

[0037] An embodiment of the present invention further provides a device for determining the capacity attenuation rate of a power - battery system, including:

[0038] An acquisition module, configured to acquire historical charging data of a target power - battery system; wherein, the historical charging data includes: multiple charging times and the highest single - cell voltage, charging current, highest single - cell temperature, and driving mileage corresponding to each charging time;

[0039] A division module, configured to divide the historical charging data into at least one charging process according to the charging time, the highest single - cell voltage, and the driving mileage;

[0040] The first determination module is configured to determine a first charging process according to the proportion of each average charging information in all the average charging information and the driving mileage; wherein, the average charging information is the average charging current and the average highest single cell temperature of each charging process.

[0041] The second determination module is configured to determine multiple charging processes with the average charging information within the same interval range as a second charging process.

[0042] The third determination module is configured to determine the capacity attenuation rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process.

[0043] Optionally, the partitioning module is specifically configured to:

[0044] Partition the historical charging data that meets the following conditions into the same charging process:

[0045] The time difference between adjacent charging times is less than or equal to a preset duration;

[0046] The highest single cell voltage corresponding to each charging time is within a preset voltage range;

[0047] The driving mileage corresponding to each charging time is the same;

[0048] Wherein, the preset voltage range is from the platform voltage to the full charge voltage, or from the platform voltage to the sub-full charge voltage.

[0049] Optionally, the device further includes:

[0050] The first calculation module is configured to calculate the charging capacity of at least one of the charging processes respectively.

[0051] Optionally, the first calculation module is specifically configured to:

[0052] Calculate the charging capacity according to multiple charging times and multiple charging currents in each charging process.

[0053] Optionally, the device further includes:

[0054] The first selection module is configured to select a highest single cell voltage as a reference voltage point at every preset voltage interval in each charging process.

[0055] The second selection module is configured to use the charging current and the highest single cell temperature corresponding to the reference voltage point as the segmented current and the segmented temperature respectively.

[0056] A second calculation module, configured to calculate the average charging current and the average maximum single cell temperature respectively according to the multiple segmented currents and the multiple segmented temperatures in each of the charging processes.

[0057] A third calculation module, configured to calculate the average charging current and the average maximum single cell temperature respectively according to the multiple segmented currents and the multiple segmented temperatures in each of the charging processes.

[0058] Optionally, the first determination module is specifically configured to:

[0059] Determine the charging process in which the ratio is the largest or the second largest and the driving mileage is greater than a preset mileage as the first charging process.

[0060] Optionally, the device further includes:

[0061] A sorting module, configured to sort the multiple average charging information;

[0062] A selection module, configured to select the smallest average charging information as the starting point information;

[0063] A fourth determination module, configured to determine multiple interval ranges according to the starting point information and a preset interval length.

[0064] Optionally, the third determination module is specifically configured to:

[0065] Fit the first driving mileage and the first charging capacity, and the multiple second driving mileages and the multiple second charging capacities to obtain a target straight line for the attenuation of the charging capacity with the driving mileage;

[0066] Determine the capacity attenuation rate according to the slope of the target straight line.

[0067] Optionally, the device further includes:

[0068] A judgment module, configured to judge whether the capacity attenuation rate is abnormal according to a life setting abnormal threshold.

[0069] Optionally, the device further includes:

[0070] An early warning module, configured to send an early warning signal when the capacity attenuation rate is abnormal.

[0071] An embodiment of the present invention further provides an electronic device, including: a processor, a memory, and a program stored on the memory and executable on the processor, where when the program is executed by the processor, the method for determining the capacity attenuation rate of the power battery system as described above is implemented.

[0072] The above technical solution of the present invention has at least the following beneficial effects:

[0073] In the above solution, historical charging data of the target power battery system is obtained; wherein, the historical charging data includes: multiple charging times and the corresponding maximum single-cell voltage, charging current, maximum single-cell temperature, and driving mileage at each charging time; according to the charging time, the maximum single-cell voltage, and the driving mileage, the historical charging data is divided into at least one charging process; according to the proportion of each average charging information in all average charging information and the driving mileage, the first charging process is determined; wherein, the average charging information includes the average charging current and the average maximum single-cell temperature of each charging process; multiple charging processes with the average charging information in the same interval range are determined as the second charging process; according to the first driving mileage and the first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process, the capacity attenuation rate of the target power battery system is determined, and the capacity change of the power battery system is evaluated according to the capacity attenuation rate, so as to analyze the health status and effectively predict abnormalities. Description of the Drawings

[0074] Figure 1 It is a schematic flow chart of a method for determining the capacity attenuation rate of a power battery system according to an embodiment of the present invention;

[0075] Figure 2 It is a block diagram of a device for determining the capacity attenuation rate of a power battery system according to an embodiment of the present invention. Detailed Embodiments

[0076] To make the technical problems, technical solutions, and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0077] An embodiment of the present invention provides a method and device for determining the capacity attenuation rate of a power battery system in view of the problem that the evaluation of the health status of a power battery system in the prior art deviates from the actual situation.

[0078] As Figure 1 shown, an embodiment of the present invention provides a method for determining the capacity attenuation rate of a power battery system, including:

[0079] Step 101, obtain historical charging data of the target power battery system; wherein, the historical charging data includes: multiple charging times and the corresponding maximum single-cell voltage, charging current, maximum single-cell temperature, and driving mileage at each charging time;

[0080] It should be noted that the historical charging data is the charging process data of the entire life cycle of the target power battery system.

[0081] Step 102: Divide the historical charging data into at least one charging process according to the charging time, the highest single-cell voltage, and the driving mileage.

[0082] It should be noted that the historical charging data includes the highest single-cell voltage, charging current, highest single-cell temperature, and driving mileage corresponding to multiple charging times in at least one charging process.

[0083] Step 103: Determine the first charging process according to the proportion of each average charging information in all average charging information and the driving mileage; wherein, the average charging information includes the average charging current and average highest single-cell temperature of each charging process.

[0084] It should be noted that use the first charging capacity and the first driving mileage corresponding to the first charging process as the standard gear coordinates in the schematic diagram of the charging capacity decay with the driving mileage.

[0085] Step 104: Determine multiple charging processes with average charging information in the same interval range as the second charging process.

[0086] Here, the average charging information is in the same interval range, that is, the average charging information belongs to the same gear. Determine multiple charging processes belonging to the same gear as the second charging process.

[0087] Plot the standard gear and the charging capacity and driving mileage corresponding to the charging processes in the same gear into the same schematic diagram of the charging capacity decay with the driving mileage.

[0088] Step 105: Determine the capacity decay rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and the multiple second driving mileages and multiple second charging capacities corresponding to the second charging process.

[0089] It should be noted that determine the capacity change of the target power battery system according to the capacity decay rate, so as to effectively and quickly identify abnormal power battery systems.

[0090] In an embodiment of the present invention, historical charging data of a target power battery system is obtained; wherein, the historical charging data includes: multiple charging times and the corresponding maximum single-cell voltage, charging current, maximum single-cell temperature, and driving mileage at each charging time; according to the charging time, the maximum single-cell voltage, and the driving mileage, the historical charging data is divided into at least one charging process; according to the proportion of each average charging information in all the average charging information and the driving mileage, a first charging process is determined; wherein, the average charging information includes the average charging current and the average maximum single-cell temperature of each charging process; multiple charging processes with the average charging information within the same interval range are determined as a second charging process; according to the first driving mileage and the first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process, the capacity attenuation rate of the target power battery system is determined, and the capacity change of the power battery system is evaluated according to the capacity attenuation rate, so as to analyze the health state and effectively predict anomalies.

[0091] Optionally, step 102, according to the charging time, the maximum single-cell voltage, and the driving mileage, dividing the historical charging data into at least one charging process includes:

[0092] Dividing the historical charging data that meets the following conditions into the same charging process:

[0093] The time difference between adjacent charging times is less than or equal to a preset duration;

[0094] The maximum single-cell voltage corresponding to each charging time is within a preset voltage range;

[0095] The driving mileage corresponding to each charging time is the same;

[0096] Wherein, the preset voltage range is from the platform voltage to the full charge voltage, or from the platform voltage to the sub-full charge voltage.

[0097] Here, the preset duration is 10 min, the platform voltage is 3.7 V, the full charge voltage is 4.15 V, and the sub-full charge voltage is 4.1 V. The historical charging data with the same driving mileage, the charging time interval less than or equal to 10 min, and the maximum single-cell voltage within the first voltage range is divided into the same charging process.

[0098] Optionally, after step 102, according to the charging time, the maximum single-cell voltage, and the driving mileage, dividing the historical charging data into at least one charging process, it further includes:

[0099] Calculating the charging capacity of at least one charging process respectively.

[0100] Here, the ampere-hour integration method is used to calculate the charging capacity of each charging process.

[0101] Specifically, calculate the charging capacity of at least one charging process, including:

[0102] Calculate the charging capacity according to multiple charging moments and multiple charging currents in each charging process.

[0103] Here, the ampere-hour integration method is adopted to calculate the charging capacity between the platform voltage of 3.7V and the full charge voltage of 4.15V and the charging capacity between the platform voltage of 3.7V and the second full charge voltage of 4.1V respectively.

[0104] Optionally, in step 103, before determining the first charging process according to the proportion of each average charging information in all average charging information and the driving mileage, it further includes:

[0105] In each charging process, select a highest single cell voltage at every preset voltage interval as the reference voltage point;

[0106] Take the charging current and the highest single cell temperature corresponding to the reference voltage point as the segmented current and the segmented temperature respectively; calculate the average charging current and the average highest single cell temperature respectively according to the multiple segmented currents and multiple segmented temperatures of each charging process.

[0107] It should be noted that in each charging process, within the range of the platform voltage from 3.7V to the full charge voltage of 4.15V, select a highest single cell voltage at every 50mV interval as the reference voltage point. Here, nine reference voltage points obtained are 3.75V, 3.8V, 3.85V, 3.9V, 3.95V, 4V, 4.05V, 4.1V, 4.15V respectively;

[0108] Corresponding to the above nine reference voltage points, nine segmented currents are obtained: current 1, current 2, current 3... current 9, and nine segmented temperatures: temperature 1, temperature 2, temperature 3... temperature 9.

[0109] Furthermore, take the average value of the nine segmented currents obtained above: current 1 to current 9 as the average charging current, and the average value of the nine segmented temperatures: temperature 1 to temperature 9 as the average highest single cell temperature.

[0110] Optionally, in step 103, when determining the first charging process according to the proportion of each average charging information in all average charging information and the driving mileage, it includes:

[0111] Determine the charging process with the largest or second largest proportion and a driving mileage greater than the preset mileage as the first charging process.

[0112] It should be noted that the preset mileage is two-thirds of the total mileage of the target power battery system.

[0113] Here, by statistically analyzing the average charging information of each charging process, that is, statistically analyzing all the average charging information of the target power battery system throughout its life cycle; obtaining the average charging information with the largest or the second largest proportion in the life cycle of the target power battery system, and the driving mileage corresponding to the largest or the second largest average charging information is greater than two-thirds of the total mileage of the target power battery system, so as to determine the first charging process.

[0114] Optionally, before step 104 of determining multiple charging processes with average charging information within the same interval range as the second charging process, it further includes:

[0115] Sorting the multiple average charging information;

[0116] Selecting the smallest average charging information as the starting point information;

[0117] Determining multiple interval ranges according to the starting point information and the preset interval length.

[0118] It should be noted that the smallest average charging current and the average highest single cell temperature are used as the starting point information; here, the preset interval length of the average charging current can be 10A, and the preset interval length of the average highest single cell temperature can be 5°C. If the starting point information is: average charging current 5A and average highest single cell temperature 15°C, then the multiple interval ranges of the average charging current are [5A 15A], [16A 26A], [27A 37A]…, and the multiple interval ranges of the average highest single cell temperature are [15°C 20°C], [21°C 26°C], [27°C 32°C]….

[0119] Here, multiple charging processes within the same interval range belong to the charging processes of the same gear, which are used as the second charging process, and in the subsequent steps, the charging capacity and the driving mileage corresponding to the charging processes of the same gear are plotted into the same schematic diagram of the attenuation of the charging capacity with the driving mileage.

[0120] Optionally, in step 105, according to the first charging capacity and the first driving mileage corresponding to the first charging process, and multiple second charging capacities and multiple second driving mileages corresponding to the second charging process, determining the capacity attenuation rate of the target power battery system includes:

[0121] Fitting the first driving mileage and the first charging capacity, as well as multiple second driving mileages and multiple second charging capacities, to obtain the target straight line of the attenuation of the charging capacity with the driving mileage;

[0122] Determining the capacity attenuation rate according to the slope of the target straight line.

[0123] It should be noted that, according to the target straight line of the charging capacity decay with the driving mileage, a schematic diagram of the charging capacity decay with the driving mileage is drawn. The abscissa is the driving mileage, and the ordinate is the charging capacity. In this schematic diagram, it includes the standard gear coordinates (the first driving mileage and the first charging capacity) and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process.

[0124] Among them, the slope of the target straight line is the capacity decay rate.

[0125] Optionally, the method further includes:

[0126] Set an abnormal threshold according to the lifespan, and determine whether the capacity decay rate is abnormal.

[0127] Here, set an abnormal threshold according to the lifespan, calculate the designed decay rate of the lifespan. When the capacity decay rate is greater than the designed decay rate of the lifespan, it is determined that the capacity decay rate of the target power battery system is abnormal.

[0128] It should be noted that the abnormal threshold set by the lifespan is the design value of the target power battery system. For example, for a power battery system of 150 Ah, with a driving mileage of 200,000 km, the corresponding abnormal threshold set by the lifespan is greater than or equal to 80%, and the designed decay rate of the lifespan is less than or equal to 1.5.

[0129] Optionally, the method further includes:

[0130] Send a warning signal when the capacity decay rate is abnormal.

[0131] Here, when the capacity decay rate is abnormal, send a warning signal to the user, so as to help the user identify the battery risk in advance, take measures, avoid affecting travel, and improve the experience.

[0132] In summary, the method for determining the capacity decay rate of the power battery system in the embodiments of the present invention can be applied to the analysis of the battery health state at different stages of the actual vehicle, without affecting the user's use, remotely obtain the historical charging data of the target power battery, divide the gears, count the slope, identify the battery risk in advance, meet the use in the whole life cycle, and improve the economic benefits.

[0133] As Figure 2 shown, the embodiments of the present invention further provide a device for determining the capacity decay rate of a power battery system, including:

[0134] An acquisition module 201, configured to acquire the historical charging data of the target power battery system; among them, the historical charging data includes: multiple charging times and the highest single-cell voltage, charging current, highest single-cell temperature, and driving mileage corresponding to each charging time;

[0135] A partitioning module 202, configured to partition historical charging data into at least one charging process according to a charging time, a highest single-cell voltage, and a driving mileage;

[0136] A first determination module 203, configured to determine a first charging process according to a proportion of each average charging information in all average charging information and a driving mileage; wherein, the average charging information is an average charging current and an average highest single-cell temperature of each charging process;

[0137] A second determination module 204, configured to determine multiple charging processes with average charging information within the same interval range as a second charging process;

[0138] A third determination module 205, configured to determine a capacity attenuation rate of a target power battery system according to a first driving mileage and a first charging capacity corresponding to the first charging process, and multiple second charging capacities and multiple second driving mileages corresponding to the second charging process.

[0139] In an embodiment of the present invention, by obtaining historical charging data of a target power battery system; wherein, the historical charging data includes: multiple charging times and a highest single-cell voltage, a charging current, a highest single-cell temperature, and a driving mileage corresponding to each charging time; partitioning the historical charging data into at least one charging process according to the charging time, the highest single-cell voltage, and the driving mileage; determining a first charging process according to a proportion of each average charging information in all average charging information and the driving mileage; wherein, the average charging information includes an average charging current and an average highest single-cell temperature of each charging process; determining multiple charging processes with average charging information within the same interval range as a second charging process; determining a capacity attenuation rate of the target power battery system according to a first driving mileage and a first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process, and evaluating the capacity change of the power battery system according to the capacity attenuation rate, so as to analyze the health state and effectively predict anomalies.

[0140] Optionally, the partitioning module 202 is specifically configured to:

[0141] Partition the historical charging data that meets the following conditions into the same charging process:

[0142] A time difference between adjacent charging times is less than or equal to a preset duration;

[0143] The highest single-cell voltage corresponding to each charging time is the same;

[0144] The driving mileage corresponding to each charging time is the same.

[0145] Optionally, the device further includes:

[0146] A first calculation module, configured to calculate the charging capacity of at least one charging process respectively.

[0147] Optionally, the first calculation module is specifically configured to:

[0148] Calculate the charging capacity according to multiple charging times and multiple charging currents in each charging process.

[0149] Optionally, the device further includes:

[0150] A first selection module, configured to select a highest single-cell voltage at each preset voltage interval as a reference voltage point in each of the charging processes;

[0151] A second selection module, configured to use the charging current and the highest single-cell temperature corresponding to the reference voltage point as a segmented current and a segmented temperature respectively;

[0152] A second calculation module, configured to calculate an average charging current and an average highest single-cell temperature respectively according to multiple segmented currents and multiple segmented temperatures in each charging process.

[0153] A third calculation module, configured to calculate an average charging current and an average highest single-cell temperature respectively according to multiple segmented currents and multiple segmented temperatures in each charging process.

[0154] Optionally, the first determination module 203 is specifically configured to:

[0155] Determine the charging process with the largest or second-largest ratio and a driving mileage greater than a preset mileage as the first charging process.

[0156] Optionally, the device further includes:

[0157] A sorting module, configured to sort multiple average charging information;

[0158] A selection module, configured to select the smallest average charging information as starting point information;

[0159] A fourth determination module, configured to determine multiple interval ranges according to the starting point information and a preset interval length.

[0160] Obtain a target straight line of the charging capacity decay with the driving mileage based on the first driving mileage and the first charging capacity, and multiple second driving mileages and multiple second charging capacities;

[0161] Determine the capacity decay rate according to the slope of the target straight line.

[0162] Optionally, the device further includes:

[0163] A judgment module, configured to judge whether the capacity decay rate is abnormal according to a life setting abnormal threshold.

[0164] Optionally, the device further includes:

[0165] An early warning module, configured to send an early warning signal when the capacity attenuation rate is abnormal.

[0166] It should be noted that the device for determining the capacity attenuation rate of the power battery system provided in the embodiments of the present invention is a device capable of executing the above-mentioned method for determining the capacity attenuation rate of the power battery system. Therefore, all embodiments of the above-mentioned method for determining the capacity attenuation rate of the power battery system are applicable to this device and can achieve the same or similar technical effects.

[0167] The embodiments of the present invention further provide an electronic device, including: a processor, a memory, and a program stored on the memory and executable on the processor. When the program is executed by the processor, it implements the method for determining the capacity attenuation rate of the power battery system as described above.

[0168] It should be noted that the electronic device provided in the embodiments of the present invention executes the method for determining the capacity attenuation rate of the power battery system as described above and has the same technical effects, which will not be elaborated here.

[0169] The above are the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for determining the capacity attenuation rate of a power battery system, characterized in that, Including: Obtaining historical charging data of a target power battery system; wherein, the historical charging data includes: a plurality of charging times and the corresponding maximum single-cell voltage, charging current, maximum single-cell temperature, and driving mileage at each charging time; Dividing the historical charging data into at least one charging process according to the charging time, the maximum single-cell voltage, and the driving mileage; Determining a first charging process according to the proportion of each average charging information in all average charging information and the driving mileage; wherein, the average charging information includes the average charging current and the average maximum single-cell temperature of each charging process; determining the first charging process according to the proportion of each average charging information in all average charging information and the driving mileage includes: counting all average charging information in the entire life cycle of the target power battery system; determining the first charging process according to the average charging information with the largest or second largest proportion in the entire life cycle of the target power battery system, and the driving mileage corresponding to the largest or second largest average charging information is greater than two-thirds of the total mileage of the target power battery system; Determining a plurality of charging processes with the average charging information in the same interval range as a second charging process; wherein, before determining a plurality of charging processes with the average charging information in the same interval range as a second charging process, it further includes: sorting a plurality of the average charging information; selecting the smallest of the average charging information as the starting information; determining a plurality of interval ranges according to the starting information and a preset interval length; Determining the capacity attenuation rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and a plurality of second driving mileages and a plurality of second charging capacities corresponding to the second charging process; wherein, determining the capacity attenuation rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and a plurality of second driving mileages and a plurality of second charging capacities corresponding to the second charging process includes: fitting the first driving mileage and the first charging capacity, and a plurality of the second driving mileages and a plurality of the second charging capacities to obtain a target straight line of the charging capacity decaying with the driving mileage; determining the capacity attenuation rate according to the slope of the target straight line.

2. The method for determining the capacity attenuation rate of the power battery system according to claim 1, wherein Dividing the historical charging data into at least one charging process according to the charging time, the maximum single-cell voltage, and the driving mileage includes: Dividing the historical charging data that meets the following conditions into the same charging process: The time difference between adjacent charging times is less than or equal to a preset duration; The maximum single-cell voltage corresponding to each charging time is within a preset voltage range; The driving mileage corresponding to each charging time is the same; Wherein, the preset voltage range is from the platform voltage to the full charge voltage, or from the platform voltage to the sub-full charge voltage.

3. The method for determining the capacity attenuation rate of the power battery system according to claim 1, wherein After dividing the historical charging data into at least one charging process according to the charging time, the maximum single-cell voltage, and the driving mileage, it further includes: Calculating the charging capacity of at least one of the charging processes respectively.

4. The method for determining the capacity attenuation rate of the power battery system according to claim 3, wherein Calculating the charging capacity of at least one of the charging processes respectively, includes: Calculating the charging capacity according to multiple charging times and multiple charging currents in each of the charging processes.

5. The method for determining the capacity attenuation rate of the power battery system according to claim 1, wherein Before determining the first charging process according to the proportion of each average charging information in all the average charging information and the driving mileage, it further includes: In each of the charging processes, selecting a highest single cell voltage at intervals of a preset voltage as a reference voltage point; Taking the charging current and the highest single cell temperature corresponding to the reference voltage point as the segmented current and the segmented temperature respectively; Calculating the average charging current and the average highest single cell temperature respectively according to multiple segmented currents and multiple segmented temperatures in each of the charging processes.

6. The method for determining the capacity attenuation rate of the power battery system according to claim 1, characterized in that, It further includes: Judging whether the capacity attenuation rate is abnormal according to a life - set abnormal threshold.

7. The method for determining the capacity attenuation rate of the power battery system according to claim 1, characterized in that It further includes: Sending a warning signal when the capacity attenuation rate is abnormal.

8. A device for determining the capacity attenuation rate of a power battery system, characterized in that, Includes: An acquisition module, configured to acquire historical charging data of a target power battery system; wherein, the historical charging data includes: multiple charging times and the highest single cell voltage, charging current, highest single cell temperature and driving mileage corresponding to each charging time; A division module, configured to divide the historical charging data into at least one charging process according to the charging time, the highest single cell voltage and the driving mileage; A first determination module, configured to determine the first charging process according to the proportion of each average charging information in all the average charging information and the driving mileage; wherein, the average charging information is the average charging current and the average highest single cell temperature of each charging process; specifically, the first determination module is configured to: count all the average charging information in the whole life cycle of the target power battery system; determine the first charging process according to the average charging information with the largest or the second largest proportion in the whole life cycle of the target power battery system, and the driving mileage corresponding to the largest or the second largest average charging information is greater than two - thirds of the total mileage of the target power battery system; A second determination module, configured to determine multiple charging processes with the average charging information in the same interval range as the second charging process; A third determination module, configured to determine the capacity attenuation rate of the target power battery system according to the first driving mileage and the first charging capacity corresponding to the first charging process, and multiple second driving mileages and multiple second charging capacities corresponding to the second charging process; specifically, the third determination module is configured to: fit the first driving mileage and the first charging capacity, and multiple second driving mileages and multiple second charging capacities to obtain a target straight line of the charging capacity decaying with the driving mileage; determine the capacity attenuation rate according to the slope of the target straight line; A sorting module, configured to sort multiple pieces of the average charging information; A selection module, configured to select the smallest piece of the average charging information as the starting information; A fourth determination module, configured to determine multiple interval ranges according to the starting information and a preset interval length.

9. An electronic device, characterized in that, Includes: A processor, a memory, and a program stored on the memory and executable on the processor, where when the program is executed by the processor, it implements the method for determining the capacity attenuation rate of the power battery system according to any one of claims 1 to 7.

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