CN117970152A - Power battery status assessment method, device, computer equipment, and storage medium - Google Patents

Abstract

The present application relates to a state evaluation method, apparatus, computer device, storage medium and computer program product of a power battery. The method comprises the following steps: determining individual actual values of a plurality of evaluation parameters based on the operating data of the vehicle to be evaluated; determining an individual nominal value of each evaluation parameter based on the operation data of the vehicle to be evaluated in the target mileage range; for any evaluation parameter, determining an individual retention rate of the aimed evaluation parameter based on the individual actual value and the individual nominal value of the aimed evaluation parameter; and based on the individual retention rate of each evaluation parameter, evaluating the aging degree of the power battery of the vehicle to be evaluated to obtain an evaluation result. By adopting the method, the accuracy of state evaluation of the power battery can be improved.

Description

Power battery status assessment method, device, computer equipment, and storage medium

Technical Field

The present application relates to the technical field of power batteries, and in particular to a method, device, computer equipment, storage medium and computer program product for evaluating the status of a power battery.

Background technique

With the rapid development of the new energy vehicle industry, a series of commercial activities such as new energy vehicle maintenance, auto insurance sales, second-hand car transactions, and power battery cascade utilization have flourished, and the business volume has increased sharply. Power batteries are the core components of new energy vehicles, accounting for about 40% of the cost of new energy vehicles. Their remaining life directly determines the safety and residual value of new energy vehicles, and is also the core parameter basis for carrying out the above business. Therefore, the evaluation technology of power battery status will inevitably become the core technology supporting the development of the new energy vehicle aftermarket.

However, due to the complexity of the chemical reactions inside lithium batteries and the many factors that affect their lifespan, the battery capacity decay process is affected by the combined coupling of multiple factors, resulting in relatively high technical difficulty in accurately evaluating the status of power batteries.

Summary of the invention

Based on this, it is necessary to provide a power battery status assessment method, device, computer equipment, computer-readable storage medium and computer program product that can improve the accuracy of power battery status assessment in order to address the above technical problems.

On the one hand, the present application provides a method for evaluating the state of a power battery, comprising:

determining individual actual values of a plurality of evaluation parameters based on operating data of the vehicle to be evaluated;

Determining individual nominal values of each of the evaluation parameters based on the operating data of the vehicle to be evaluated within a target mileage range;

For any evaluation parameter, based on the individual actual value and the individual nominal value of the evaluation parameter, determine the individual retention rate of the evaluation parameter;

Based on the individual retention rates of the evaluation parameters, the aging degree of the power battery of the vehicle to be evaluated is evaluated to obtain an evaluation result.

In one embodiment, determining the individual retention rate of the targeted evaluation parameter based on the individual actual value and the individual nominal value of the targeted evaluation parameter comprises:

The ratio of the individual actual value to the individual nominal value of the evaluation parameter is determined, and the ratio is used as the individual retention rate of the evaluation parameter.

In one embodiment, the aging degree of the power battery of the vehicle to be evaluated is evaluated based on the individual retention rate of each evaluation parameter to obtain an evaluation result, including:

Determining an initial value of each of the evaluation parameters, and drawing a first radar chart based on each of the initial values;

Based on the individual retention rates of each of the evaluation parameters, a second radar chart is drawn;

A ratio of the area of the second radar map to the area of the first radar map is determined, and the ratio is used as an evaluation result obtained by evaluating the aging degree of the power battery.

In one of the embodiments, the method further comprises: determining a vehicle group to which the vehicle to be evaluated belongs;

Determining a group actual value of each evaluation parameter based on the operation data of the vehicle group;

Determining a group nominal value of each evaluation parameter based on the operation data of the vehicle group within the target mileage range;

For any evaluation parameter, based on the actual value of the population and the nominal value of the population for the evaluation parameter, the population retention rate of the evaluation parameter is determined.

In one embodiment, the aging degree of the power battery of the vehicle to be evaluated is evaluated based on the individual retention rate of each evaluation parameter to obtain an evaluation result, including:

Based on the individual retention rates of each of the evaluation parameters, a second radar chart is drawn;

Based on the population retention rate of each evaluation parameter, a third radar chart is drawn;

A ratio of the area of the second radar map to the area of the third radar map is determined, and the ratio is used as an evaluation result obtained by evaluating the aging degree of the power battery.

In one of the embodiments, the method further comprises: obtaining a plurality of resource exchange values of the vehicle to be evaluated;

The predicted resource exchange value of the vehicle to be evaluated is determined according to the individual retention rate, the group retention rate, and an average of the plurality of resource exchange values.

In one embodiment, the operating data includes at least one of the following:

Mileage, charging time, number of charge and discharge cycles, total current, total voltage, battery temperature, battery cell voltage during charging, peak motor temperature during driving, and peak battery temperature during charging;

The evaluation parameters include at least one of the following:

Segment capacity, charging amount per 100 kilometers, self-discharge rate, voltage consistency value, motor temperature peak, battery temperature peak.

On the other hand, the present application also provides a power battery status assessment device, comprising:

A first determination module, configured to determine individual actual values of a plurality of evaluation parameters based on operating data of the vehicle to be evaluated;

A second determination module, configured to determine an individual nominal value of each of the evaluation parameters based on the operating data of the vehicle to be evaluated within a target mileage range;

A third determination module is used to determine, for any evaluation parameter, an individual retention rate of the evaluation parameter based on the individual actual value and the individual nominal value of the evaluation parameter;

The evaluation module is used to evaluate the aging degree of the power battery of the vehicle to be evaluated based on the individual retention rate of each evaluation parameter to obtain an evaluation result.

On the other hand, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

determining individual actual values of a plurality of evaluation parameters based on operating data of the vehicle to be evaluated;

Determining individual nominal values of each of the evaluation parameters based on the operating data of the vehicle to be evaluated within a target mileage range;

For any evaluation parameter, based on the individual actual value and the individual nominal value of the evaluation parameter, determine the individual retention rate of the evaluation parameter;

Based on the individual retention rates of the evaluation parameters, the aging degree of the power battery of the vehicle to be evaluated is evaluated to obtain an evaluation result.

On the other hand, the present application also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

determining individual actual values of a plurality of evaluation parameters based on operating data of the vehicle to be evaluated;

Determining individual nominal values of each of the evaluation parameters based on the operating data of the vehicle to be evaluated within a target mileage range;

For any evaluation parameter, based on the individual actual value and the individual nominal value of the evaluation parameter, determine the individual retention rate of the evaluation parameter;

Based on the individual retention rates of the evaluation parameters, the aging degree of the power battery of the vehicle to be evaluated is evaluated to obtain an evaluation result.

On the other hand, the present application also provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

Determining individual actual values of a plurality of evaluation parameters based on operating data of the vehicle to be evaluated;

Determining individual nominal values of each of the evaluation parameters based on the operating data of the vehicle to be evaluated within a target mileage range;

For any evaluation parameter, based on the individual actual value and the individual nominal value of the evaluation parameter, determine the individual retention rate of the evaluation parameter;

Based on the individual retention rates of the evaluation parameters, the aging degree of the power battery of the vehicle to be evaluated is evaluated to obtain an evaluation result.

The above-mentioned power battery status assessment method, device, computer equipment, storage medium and computer program product first determine the individual actual values of multiple assessment parameters based on the operating data of the vehicle to be assessed, so that the comprehensiveness of the assessment parameters can be improved by combining various assessment parameters to complete the subsequent status assessment; then, based on the operating data of the vehicle to be assessed within the target mileage range, the individual nominal value of each of the assessment parameters is determined; in this way, the balance of determining the individual nominal value can be improved; then, for any assessment parameter, based on the individual actual value and the individual nominal value of the assessment parameter, the individual retention rate of the assessment parameter is determined; finally, based on the individual retention rate of each assessment parameter, the aging degree of the power battery of the vehicle to be assessed is assessed to obtain an assessment result. In this way, the status assessment of the power battery is performed in a comprehensive combination of the individual retention rates of multiple assessment parameters, which can effectively improve the accuracy of the status assessment of the power battery.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of a process of evaluating a power battery status in one embodiment;

FIG2 is a schematic diagram of a radar chart for status assessment based on individual retention rates in one embodiment;

FIG3 is a schematic diagram of a radar chart for status assessment based on group retention rate in another embodiment;

FIG4 is a structural block diagram of a device for evaluating a state of a power battery in one embodiment;

FIG. 5 is a diagram showing the internal structure of a computer device in one embodiment.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

In an exemplary embodiment, as shown in FIG1 , a method for evaluating the state of a power battery is provided, which is described by applying the method to a computer device (the computer device may be a terminal or a server), and includes the following steps 102 to 108. Among them:

Step 102 : determining individual actual values of a plurality of evaluation parameters based on the operating data of the vehicle to be evaluated.

In actual implementation, the computer device can determine multiple evaluation parameters for evaluating the aging degree of the power battery of the vehicle according to the operating data of the vehicle to be evaluated. After determining the multiple evaluation parameters, the aging degree of the power battery of the vehicle to be evaluated can be determined according to the evaluation parameters. The operating data of the vehicle includes the actual values of multiple operating parameters, and the actual value of each evaluation parameter can be determined according to the value of at least one operating parameter. The actual value of the evaluation parameter can be called the individual actual value of the evaluation parameter relative to a single vehicle, and can be called the group actual value of the evaluation parameter relative to a group of vehicles.

With respect to the operating data, the operating data includes at least one of the following: mileage, charging time, number of charge and discharge cycles, total current, total voltage, battery temperature, battery cell voltage during charging, peak motor temperature during driving, and peak battery temperature during charging.

Accordingly, the evaluation parameters include at least one of the following: segment capacity, charging amount per 100 kilometers, self-discharge rate, voltage consistency value, motor temperature peak, and battery temperature peak.

Among them, for the segment capacity in the evaluation parameters, the computer device can determine the charging capacity for the power battery as the segment capacity in the evaluation parameters based on the total current and charging time in the charging process in the operating data, when the battery state of charge SOC of the power battery of the vehicle to be evaluated is in the specified growth segment. For example, the charging capacity within the 5% SOC segment range is calculated using the ampere-hour integration method, and the 5% SOC segment range refers to the segment range in which the SOC change value during the charging process is 5%, such as 85%-90%.

For the charging amount per 100 kilometers in the evaluation parameters, the charging capacity of the vehicle to be evaluated for running 100 kilometers can be determined based on the total current and charging time during the charging process, as the charging amount per 100 kilometers in the evaluation parameters. Based on the total current and time during the charging process of the new energy vehicle to be evaluated, the charging amount of the vehicle running 100 kilometers is calculated using the ampere-hour integration method.

For the self-discharge rate in the evaluation parameters, the time-averaged voltage difference before and after the vehicle to be evaluated is turned off and left stationary can be determined based on the total voltage and charging time during the charging process, which is used as the self-discharge rate in the evaluation parameters.

For the voltage consistency value in the evaluation parameters, during the charging process, if the SOC of the power battery of the vehicle to be evaluated reaches the specified threshold, the highest voltage value and the lowest voltage value of all battery cells in the battery pack of the vehicle to be evaluated are determined, and the difference between the highest voltage value and the lowest voltage value is used as the voltage consistency value in the evaluation parameters. For example, based on the new energy vehicle to be evaluated, the difference between the highest and lowest voltage values of all battery cells in the battery pack when the battery SOC reaches 90% during the charging process is extracted.

The peak temperature of the motor of the vehicle to be evaluated during the most recent driving process is obtained as the peak temperature of the motor in the evaluation parameters; the peak temperature of the battery pack of the vehicle to be evaluated during the most recent charging process is obtained as the peak temperature of the battery in the evaluation parameters.

Step 104 : determining individual nominal values of various evaluation parameters based on the operating data of the vehicle to be evaluated within the target mileage range.

In actual implementation, for a single vehicle to be evaluated, the average value of each evaluation parameter within the target mileage range can be determined through the vehicle's operating data within the target mileage range. For ease of description, the average value is used as the individual nominal value of the evaluation parameter. For example, taking the target mileage range of 0-500 kilometers as an example, the actual value of each evaluation parameter when the vehicle to be evaluated runs 100 kilometers, 200 kilometers, 300 kilometers, 400 kilometers, and 500 kilometers can be determined respectively. For each evaluation parameter, the average of these five actual values is used as the individual nominal value of the evaluation parameter.

Step 106 : for any evaluation parameter, based on the individual actual value and the individual nominal value of the evaluation parameter, determine the individual retention rate of the evaluation parameter.

In actual implementation, the retention rate refers to the retention ratio of the actual value of the evaluation parameter relative to the nominal value of the evaluation parameter. For example, the capacity retention rate generally refers to the ratio of the capacity that can be maintained after a certain period of use to the initial capacity. The higher the capacity retention rate, the better the stability of the battery. Therefore, in order to accurately evaluate the aging degree of the power battery of the vehicle to be evaluated, the individual retention rate of each evaluation parameter is first determined for the vehicle to be evaluated. The individual retention rate of each evaluation parameter can be determined by determining the ratio of the individual actual value to the individual nominal value of the evaluation parameter, and using the ratio as the individual retention rate of the evaluation parameter.

Step 108 , based on the individual retention rates of the evaluation parameters, the aging degree of the power battery of the vehicle to be evaluated is evaluated to obtain an evaluation result.

In actual implementation, the computer device evaluates the aging degree of the power battery of the evaluation vehicle through the current value (i.e., actual value) of the individual retention rate of each evaluation parameter and the initial value of the individual retention rate of each evaluation parameter to obtain the evaluation result. It should be noted that, in view of the large number of evaluation parameters, the computer device can draw a radar chart composed of the individual retention rates of all evaluation parameters, simplifying the operation of the aging degree of the power battery to the operation of determining the area of the radar chart. A radar chart is a visual chart, also known as a spider chart, a star chart, or a polar coordinate chart. It starts from a central point and extends multiple rays outward from the central point, each ray representing the retention rate of an evaluation parameter. The points or line segments on each ray represent the values of the retention rate of the evaluation parameter in different dimensions. In this way, it can not only reduce the consumption of computing resources, but also ensure the accuracy of the evaluation, and more intuitively display the aging degree of the power battery.

In the above-mentioned power battery status assessment method, the individual actual values of multiple assessment parameters are determined based on the operating data of the vehicle to be assessed. In this way, the comprehensiveness of the assessment parameters can be improved by fully combining various assessment parameters to complete the subsequent status assessment; based on the operating data of the vehicle to be assessed within the target mileage range, the individual nominal values of each of the assessment parameters are determined; in this way, the balance of determining the individual nominal values can be improved, and for any assessment parameter, the individual retention rate of the assessment parameter is determined based on the individual actual value and the individual nominal value of the assessment parameter; based on the individual retention rate of each assessment parameter, the aging degree of the power battery of the vehicle to be assessed is assessed to obtain an assessment result. In this way, the status assessment of the power battery can be performed while fully combining the individual retention rates of multiple assessment parameters, effectively improving the accuracy of the status assessment of the power battery.

The evaluation method is described. In an exemplary embodiment, the aging degree of the power battery of the evaluated vehicle is evaluated based on the individual retention rate of each evaluation parameter to obtain an evaluation result, including: determining the initial value of each evaluation parameter, and drawing a first radar chart based on each initial value; drawing a second radar chart based on the individual retention rate of each evaluation parameter; determining the ratio of the area of the second radar chart to the area of the first radar chart, and using the ratio as the evaluation result obtained by evaluating the aging degree of the power battery.

In actual implementation, for each evaluation parameter, when each power battery leaves the factory, an initial value of the individual retention rate of each evaluation parameter will be set, usually set to 100%. The computer device draws a first radar chart based on the initial value of the individual retention rate of each evaluation parameter, and draws a second radar chart based on the current value (actual value) of the individual retention rate of each evaluation parameter, and determines the area of the first radar chart and the area of the second radar chart through a preset polygon area calculation method. The ratio of the area of the first radar chart to the area of the second radar chart is directly used as the evaluation result obtained by evaluating the aging degree of the power battery.

For example, as shown in Figure 2, Figure 2a shows a first radar chart determined according to the initial value of the individual retention rate of each evaluation parameter, and Figure 2b shows a second radar chart determined according to the current value of the individual retention rate of each evaluation parameter. The area of the first radar chart is determined to be S1, and the area of the second radar chart is determined to be S2, then the aging score of the power battery to be evaluated is S1/S2.

In this embodiment, the method of determining the aging degree of the power battery to be evaluated is converted into a method of determining the area of different radar charts, which can reduce the computational complexity of evaluating the aging degree of the power battery. At the same time, the aging degree of the power battery can be intuitively displayed through the radar chart.

It should be noted that when evaluating the aging degree of the power battery, in addition to evaluating the initial value of the individual retention rate of the evaluation parameter, in order to improve the comprehensiveness of the evaluation result, the group retention rate of the evaluation parameter can also be evaluated. The group retention rate of the evaluation parameter is explained. In an exemplary embodiment, the vehicle group to which the vehicle to be evaluated belongs is determined; based on the operating data of the vehicle group, the group actual value of each evaluation parameter is determined; based on the operating data of the vehicle group within the target mileage range, the group nominal value of each evaluation parameter is determined; for any evaluation parameter, based on the group actual value and the group nominal value of the evaluation parameter, the group retention rate of the evaluation parameter is determined.

In actual implementation, first determine the vehicle group to which the vehicle to be evaluated belongs. The factory configuration of the power batteries of each vehicle in the vehicle group is consistent. In order to ensure the evaluation accuracy, each vehicle in the vehicle group can be a vehicle of the same model, the same operating nature, and the same operating environment. For each evaluation parameter, determine the actual value of the current evaluation parameter of N vehicles, and take the average of the actual values of the N current evaluation parameters as the group actual value of the evaluation parameter. Within the target mileage range, for each vehicle in the vehicle group, determine the average value of any evaluation parameter for each vehicle as the group nominal value of the evaluation parameter. The ratio of the group actual value to the group nominal value of each evaluation parameter is taken as the group retention rate of the evaluation parameter.

Exemplarily, the vehicle group includes 100 vehicles. For evaluation parameter A, 100 current values of evaluation parameter A are determined, and the 100 current values are averaged to obtain the group actual value of evaluation parameter A. The actual values of evaluation parameter A in the vehicle group within the running mileage of 0-500 kilometers are counted. It is assumed that 1000 actual values of evaluation parameter A are obtained, and the average of these 1000 actual values of evaluation parameter A is taken as the group nominal value of evaluation parameter A. Finally, the ratio of the group actual value of evaluation parameter A to the group nominal value of evaluation parameter A is taken as the group retention rate of evaluation parameter A.

In this embodiment, the group retention rate of the evaluation parameter is determined by the relevant values of the evaluation parameter in the vehicle group, thereby improving the calculation accuracy of the group retention rate.

In an exemplary embodiment, a method for evaluating the aging degree of a power battery of a vehicle to be evaluated based on individual retention rates of evaluation parameters and group retention rates of evaluation parameters is described. Specifically: based on the individual retention rates of each evaluation parameter, a second radar chart is drawn; based on the group retention rates of each evaluation parameter, a third radar chart is drawn; the ratio of the area of the second radar chart to the area of the third radar chart is determined, and the ratio is used as the evaluation result obtained by evaluating the aging degree of the power battery.

In actual implementation, the computer device draws a second radar chart according to the actual value of the individual retention rate of each evaluation parameter, and draws a third radar chart according to the current value (actual value) of the group retention rate of each evaluation parameter, and determines the area of the second radar chart and the area of the third radar chart by a preset polygon area calculation method. The ratio of the area of the second radar chart to the area of the third radar chart is directly used as the evaluation result obtained by evaluating the aging degree of the power battery.

For example, as shown in Figure 3, a in Figure 3 shows a second radar chart determined according to the actual value of the individual retention rate of each evaluation parameter, and b in Figure 3 shows a third radar chart determined according to the actual value of the group retention rate of each evaluation parameter. The area of the second radar chart is determined to be S2, and the area of the third radar chart is determined to be S3, then the aging degree score of the power battery to be evaluated is S2/S3.

In this embodiment, the group retention rate of the evaluation parameters and the individual retention rate of the evaluation parameters are combined to jointly evaluate the aging degree of the power battery, which can improve the comprehensiveness of the evaluation operation and provide the accuracy of the evaluation result.

In an exemplary embodiment, after determining the state of the power battery of the vehicle to be evaluated, the predicted resource exchange value of the vehicle to be evaluated can also be determined based on the current state of the power battery, specifically including: obtaining multiple resource exchange values of the vehicle to be evaluated; determining the predicted resource exchange value of the vehicle to be evaluated based on the individual retention rate, the group retention rate, and the average of multiple resource exchange values.

In actual implementation, the resource exchange value of the vehicle to be evaluated can be predicted based on the evaluation results of the aging degree of the power battery. The specific prediction method can be to first obtain the resource exchange mean corresponding to multiple resource exchange values of the vehicle to be evaluated; then, as mentioned above, determine the aging degree score of the vehicle to be evaluated based on the individual retention rate and the group retention rate, and use the product of the resource exchange mean and the score as the predicted resource exchange value of the vehicle to be evaluated.

In this embodiment, the resource exchange value of the vehicle to be evaluated is determined through the evaluation result, which can improve the accuracy of the predicted resource exchange value and expand the application scenarios of the scoring results.

The aging status of the power battery is collaboratively evaluated based on the individual retention rate of the evaluation parameters and the group retention rate of the evaluation parameters to maintain the comprehensiveness of the evaluation.

To explain in detail the power battery status assessment method in the present application, an embodiment is used for illustration below. In this embodiment, the aging degree of the power battery is collaboratively assessed based on online assessment of individual operating parameters and online assessment based on group performance parameters. This is a two-level online assessment method for new energy vehicle performance based on big data.

First, the online evaluation based on individual operating parameters is explained, wherein the online evaluation based on individual operating parameters refers to an evaluation method that uses the operating data of a single vehicle to determine the evaluation parameters required for evaluating the aging degree of the vehicle, and then uses the retention rate of the evaluation parameters to predict the aging degree of the vehicle. For the sake of convenience, the retention rate of the evaluation parameters relative to a single vehicle can be referred to as the individual retention rate in the previous text.

The specific implementation of online evaluation based on individual operating parameters is described. Based on the collected new energy vehicle operation big data, the operating data corresponding to the operating parameters such as the operating mileage, time, number of charge and discharge cycles, total current, total voltage, battery temperature, battery cell voltage during charging, and motor peak temperature and battery peak temperature during driving of the new energy vehicle to be evaluated are obtained.

The method of determining the evaluation parameters according to various operating parameters is as follows:

According to the total current and time of the charging process in the operating data, the segment capacity in the evaluation parameters is determined: the charging capacity within the 5% SOC segment is calculated by the total current and time of the charging process of the new energy vehicle to be evaluated using the ampere-hour integration method as the segment capacity in the evaluation parameters. Among them, the 5% SOC segment can be understood as the growth change value of the SOC value is 5%, and the corresponding segment can be any segment where the SOC value is located with a segment interval of 5%, such as the SOC value increases from 85% to 90%.

According to the total current and time of the charging process in the operating data, the charging amount per 100 kilometers in the evaluation parameters is determined: based on the total current and time of the charging process of the new energy vehicle to be evaluated, the charging amount of the vehicle for 100 kilometers is calculated using the ampere-hour integration method as the evaluation parameter - the charging amount per 100 kilometers.

Based on the total voltage and time of the new energy vehicle battery to be evaluated, the time-averaged voltage difference before and after the vehicle is turned off and stationary (the system is turned off and not charged) is calculated as the evaluation parameter - the self-discharge rate.

According to the new energy vehicle to be evaluated, the difference between the highest and lowest voltages of all battery cells in the battery pack when the battery SOC reaches 90% during the charging process is extracted as the evaluation parameter - voltage consistency.

The peak motor temperature of the new energy vehicle during the most recent trip is extracted as the evaluation parameter - the peak motor temperature.

The peak temperature of the battery pack of the new energy vehicle during the most recent charging process is extracted as the evaluation parameter - the peak battery temperature.

Through the above method, combined with the operating data of the vehicle to be evaluated, the actual value of each evaluation parameter is obtained, and then the mean value of each evaluation parameter within the mileage range of 0 to 500 kilometers of the vehicle to be evaluated is calculated through the determination method of the above evaluation parameters as the nominal value of the above evaluation parameters of the vehicle. For example, the values of the above evaluation parameters for the vehicle running 100 kilometers, 200 kilometers, 300 kilometers, 400 kilometers, and 500 kilometers are determined respectively. For any evaluation parameter, the 5 values obtained are averaged, and the obtained mean value is used as the nominal value of the evaluation parameter. For each evaluation parameter, the retention rate of the evaluation parameter is determined according to the actual value of the evaluation parameter and the corresponding nominal value (the retention rate of a single vehicle relative to the evaluation parameter is called the personal retention rate). The individual retention rates of the evaluation parameters are as follows: take the current section capacity of the vehicle to be evaluated/nominal section capacity = capacity retention rate, take the nominal values of the vehicle to be evaluated's charging capacity per 100 kilometers, self-discharge rate, voltage consistency, motor temperature peak, battery temperature peak and other parameters and the ratio of the current values of each parameter as: charging capacity retention rate per 100 kilometers, self-discharge retention rate, voltage consistency retention rate, motor temperature peak retention rate, battery temperature peak retention rate.

In practical applications, the state of the power battery can be evaluated based on the individual retention rates of the evaluation parameters. The state can indicate the degree of aging of the power battery. The specific determination method is: when evaluating new energy vehicles, the initial values of the individual retention rates of the above-mentioned evaluation parameters are used to draw a radar chart as shown in Figure 2a. The initial value of the individual retention rate is usually 100%. The shaded area S1 in the radar chart of Figure 2 (a) is determined. The actual values of the individual retention rates of the above-mentioned evaluation parameters are used to draw a radar chart as shown in Figure 2b. The shaded area S2 in the radar chart of Figure 2 (b) is calculated. S2/S1 is the aging score of the vehicle to be evaluated.

Furthermore, in order to improve the comprehensiveness of the evaluation of the power battery status of a single vehicle to be evaluated, the status of the power battery of the vehicle to be evaluated can be comprehensively evaluated by determining the actual value of the group retention rate of each evaluation parameter relative to the vehicle group, and then combining the actual value of the individual retention rate of the aforementioned evaluation parameters relative to the single vehicle to be evaluated.

The online evaluation based on group performance parameters is described. The group performance parameters are actually evaluation parameters relative to the vehicle group.

The vehicle groups are divided based on vehicle models, vehicle attributes, and cities. Based on the operating data of new energy vehicles collected under the national standard 32960, all vehicles that have the same model and attributes as the vehicle to be evaluated and operate in the same city are obtained to construct a vehicle group.

Based on the above-mentioned determination method of the actual value of the evaluation parameter relative to the individual, with 10,000 km as the gradient, the segment capacity, 100 km charging amount, self-discharge rate, voltage consistency, motor temperature peak, battery temperature peak, etc. of the new energy vehicle group in different operating mileage segments are calculated respectively. The average value of each evaluation parameter is used as the group parameter in different operating mileage segments (that is, the evaluation parameter is relative to the vehicle group); the current segment capacity of the vehicle group/nominal segment capacity = capacity retention rate, the nominal value of the 100 km charging amount, self-discharge rate, voltage consistency, motor temperature peak, battery temperature peak and other parameters of the vehicle to be evaluated and the ratio of the current value of each parameter are respectively used as: the 100 km charging amount retention rate relative to the vehicle group (that is, the 100 km charging amount group retention rate in the previous text), the self-discharge retention rate relative to the vehicle group (that is, the self-discharge group retention rate in the previous text), the voltage consistency retention rate relative to the vehicle group, the motor temperature peak retention rate relative to the vehicle group, and the battery temperature peak retention rate relative to the vehicle group.

When evaluating a vehicle, the individual retention rate of the 8 evaluation parameters of the vehicle to be evaluated and the group retention rate of the 8 evaluation parameters under the corresponding mileage segment are taken to determine the corresponding ratios and calculate the corresponding scores. If the ratio is > 1, the parameter is recorded as excellent, greater than 0.6 and less than 1 is recorded as good, and less than 0.6 is recorded as poor.

The above method is used to calculate the mean of each evaluation parameter in the range of 0-500 km of the vehicle group as the nominal value of the above evaluation parameters of the vehicle group (also known as the group nominal value). The mean of the eight evaluation parameters of the vehicle group in different mileage segments is compared with the group nominal value and plotted in the radar chart to calculate the corresponding area S3, as shown in Figure 3 (b).

In addition, S2/S3=B is calculated as the group evaluation parameter. When valuing new energy vehicles, the average quotation C of the current vehicles is obtained through the Internet, and the product of the average quotation C and the group evaluation statement B is used as the current quotation.

By using the embodiments of the present application, accurate online evaluation of the performance of the power battery in a vehicle environment can be achieved; the problem of high cost of power battery testing can be solved, and the convenience and reliability of online testing can be improved. The following beneficial effects can be achieved:

1) Realize effective online evaluation of active and retired new energy vehicles

In this embodiment, the vehicle status is evaluated completely based on the big data of new energy vehicles that meet the current new energy vehicle collection standards, without the need for physical testing equipment. Therefore, the evaluation process can be carried out completely online, which is suitable for the residual value evaluation of active and retired new energy vehicles, and fully meets the development needs of the new energy vehicle aftermarket.

2) The detection process is convenient and reliable

When using this embodiment to evaluate the vehicle status, it is only necessary to use the online system to enter the vehicle VIN code and other key information to complete the evaluation query operation, which is convenient and quick; at the same time, all algorithms in the evaluation process are based on the real data of vehicle operation, and there is no extension speculation process, which has high reliability and strong interpretability.

3) Low testing cost

This embodiment completely evaluates the vehicle status based on the big data of new energy vehicles under the current new energy vehicle collection standards. It does not require the use of physical testing equipment, and the detection and evaluation process does not require traditional charging and discharging processes. There is almost no equipment aging maintenance cost, site fee, electricity fee and other testing and installation costs, and the detection and evaluation process is low-cost.

4) It can realize dual evaluation of vehicle performance and value retention rate

This embodiment can calculate the aging status of key components such as the vehicle motor and battery based on the current operating parameters of the vehicle, and accurately evaluate the aging status of the vehicle performance; at the same time, combined with the market quotation of used cars, the current residual value of the vehicle can be reasonably evaluated, which is highly feasible and has broad market prospects.

It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

Based on the same inventive concept, the embodiment of the present application also provides a power battery status assessment device for implementing the power battery status assessment method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of one or more power battery status assessment devices provided below can refer to the limitations of the power battery status assessment method above, and will not be repeated here.

In an exemplary embodiment, as shown in FIG. 4 , a power battery status evaluation device is provided, including: a first determination module 410 , a second determination module 420 , a third determination module 430 and an evaluation module 440 , wherein:

The first determination module 410 is configured to determine individual actual values of a plurality of evaluation parameters based on the operating data of the vehicle to be evaluated.

The second determination module 420 is used to determine the individual nominal value of each evaluation parameter based on the operating data of the vehicle to be evaluated within the target mileage range.

The third determination module 430 is used to determine, for any evaluation parameter, an individual retention rate of the evaluation parameter based on the individual actual value and the individual nominal value of the evaluation parameter.

The evaluation module 440 is used to evaluate the aging degree of the power battery of the vehicle to be evaluated based on the individual retention rate of each evaluation parameter to obtain an evaluation result.

In one embodiment, the third determination module is further used to determine the ratio of the individual actual value to the individual nominal value of the targeted evaluation parameter, and use the ratio as the individual retention rate of the targeted evaluation parameter.

In one embodiment, the evaluation module is also used to determine the initial value of each evaluation parameter, and draw a first radar chart based on each initial value; draw a second radar chart based on the individual retention rate of each evaluation parameter; determine the ratio of the area of the second radar chart to the area of the first radar chart, and use the ratio as the evaluation result obtained by evaluating the aging degree of the power battery.

In one embodiment, the third determination module is also used to determine the vehicle group to which the vehicle to be evaluated belongs; determine the group actual value of each evaluation parameter based on the operating data of the vehicle group; determine the group nominal value of each evaluation parameter based on the operating data of the vehicle group within the target mileage range; for any evaluation parameter, determine the group retention rate of the evaluation parameter based on the group actual value and the group nominal value of the evaluation parameter.

In one embodiment, the third determination module is further used to draw a second radar chart based on the individual retention rate of each evaluation parameter; draw a third radar chart based on the group retention rate of each evaluation parameter; determine the ratio of the area of the second radar chart to the area of the third radar chart, and use the ratio as an evaluation result obtained by evaluating the aging degree of the power battery.

In one embodiment, the evaluation module is further used to obtain multiple resource exchange values of the vehicle to be evaluated; and determine the predicted resource exchange value of the vehicle to be evaluated based on the individual retention rate, the group retention rate, and the average of the multiple resource exchange values.

In one embodiment, the operating data includes at least one of the following: mileage, charging time, number of charge and discharge cycles, total current, total voltage, battery temperature, battery cell voltage during charging, motor peak temperature during driving, and battery peak temperature during charging.

In one embodiment, the evaluation parameters include at least one of the following: segment capacity, charging amount per 100 kilometers, self-discharge rate, voltage consistency value, motor temperature peak value, battery temperature peak value.

Each module in the above-mentioned power battery status assessment device can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

In an exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be shown in FIG5. The computer device includes a processor, a memory, an input/output interface (Input/Output, referred to as I/O) and a communication interface. Among them, the processor, the memory and the input/output interface are connected through a system bus, and the communication interface is connected to the system bus through the input/output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input/output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a state assessment method of a power battery is implemented.

Those skilled in the art will understand that the structure shown in FIG. 5 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims (10)

1. A method of evaluating a state of a power cell, the method comprising:

Determining individual actual values of a plurality of evaluation parameters based on the operating data of the vehicle to be evaluated;

Determining an individual nominal value of each evaluation parameter based on the operation data of the vehicle to be evaluated in the target mileage range;

For any evaluation parameter, determining an individual retention rate of the aimed evaluation parameter based on the individual actual value and the individual nominal value of the aimed evaluation parameter;

And based on the individual retention rate of each evaluation parameter, evaluating the aging degree of the power battery of the vehicle to be evaluated to obtain an evaluation result.

2. The method of claim 1, wherein the determining the individual retention of the targeted evaluation parameter based on the individual actual value and the individual nominal value of the targeted evaluation parameter comprises:

a ratio of the individual actual value of the targeted evaluation parameter to the individual nominal value is determined and is taken as the individual retention rate of the targeted evaluation parameter.

3. The method according to claim 1, wherein the evaluating the degree of aging of the power battery of the vehicle under evaluation based on the individual retention rate of each evaluation parameter to obtain an evaluation result includes:

determining initial values of all the evaluation parameters, and drawing a first radar chart based on the initial values;

Drawing a second radar map based on the individual retention of each of the evaluation parameters;

and determining the ratio of the area of the second radar chart to the area of the first radar chart, and taking the ratio as an evaluation result obtained by evaluating the aging degree of the power battery.

4. The method according to claim 1, wherein the method further comprises:

Determining a vehicle group to which the vehicle to be evaluated belongs;

determining a population actual value of each evaluation parameter based on the operating data of the vehicle population;

determining a group nominal value of each evaluation parameter based on the operation data of the vehicle group in the target mileage range;

for any evaluation parameter, determining the population retention of the targeted evaluation parameter based on the population actual value and the population nominal value of the targeted evaluation parameter.

5. The method according to claim 4, wherein the evaluating the degree of aging of the power battery of the vehicle under evaluation based on the individual retention rate of each evaluation parameter to obtain the evaluation result includes:

Drawing a second radar map based on the individual retention of each of the evaluation parameters;

Drawing a third radar map based on the population retention of each of the evaluation parameters;

and determining the ratio of the area of the second radar chart to the area of the third radar chart, and taking the ratio as an evaluation result obtained by evaluating the aging degree of the power battery.

6. The method according to claim 4, wherein the method further comprises:

Acquiring a plurality of resource exchange values of the vehicle to be evaluated;

and determining the predicted resource exchange value of the vehicle to be evaluated according to the individual retention rate, the group retention rate and the average value of the resource exchange values.

7. The method of any one of claims 1 to 6, wherein the operational data comprises at least one of:

Running mileage, charging time, cyclic charge and discharge times, total current, total voltage, battery temperature, battery cell voltage and motor peak temperature in the driving process in the charging process, and battery peak temperature in the charging process;

the evaluation parameters include at least one of:

Segment capacity, charge per hundred kilometers, self-discharge rate, voltage uniformity value, motor temperature peak, battery temperature peak.

8. A state evaluation device of a power battery, characterized by comprising:

a first determination module for determining individual actual values of a plurality of evaluation parameters based on the operation data of the vehicle to be evaluated;

The second determining module is used for determining the individual nominal value of each evaluation parameter based on the operation data of the vehicle to be evaluated in the target mileage range;

a third determining module, configured to determine, for any one of the evaluation parameters, an individual retention rate of the evaluation parameter based on the individual actual value and the individual nominal value of the evaluation parameter;

And the evaluation module is used for evaluating the aging degree of the power battery of the vehicle to be evaluated based on the individual retention rate of each evaluation parameter to obtain an evaluation result.

9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 7 when the computer program is executed.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.