Discharge power adjustment method and device, electronic equipment and storage medium

Abstract

The application discloses a discharge power adjustment method and device, electronic equipment and storage medium, and relates to the technical field of power batteries and the like. The discharge power adjustment method comprises the following steps: acquiring current operation parameters of a power battery; in response to the minimum single cell voltage being less than a preset under-voltage voltage threshold, performing feature extraction on the current operation parameters to obtain a feature vector of a current working condition; determining the degree of coincidence between the current working condition and at least one preset working condition based on the distance between the feature vector of the current working condition and the clustering centers of a plurality of preset working conditions; determining a target power reduction ratio based on the degree of coincidence and the preset working condition corresponding power reduction ratio, and adjusting the discharge power based on the target power reduction ratio. The application pre-divides a plurality of under-voltage working conditions, different under-voltage working conditions correspond to different power reduction ratios, the target power reduction ratio is comprehensively determined according to the actual situation of the current working condition, the discharge power is reasonably limited at the end of the discharge working condition, and the probability of battery under-voltage failure is reduced.

Description

Technical Field

[0001] This application relates to the technical fields of power batteries, and in particular to a method, apparatus, electronic device and storage medium for adjusting discharge power. Background Technology

[0002] Currently, electric vehicles require a pre-undervoltage handling strategy to control discharge power when the individual cell voltage is relatively low at the end of the discharge cycle, in order to protect the battery and maintain power stability. Pre-undervoltage strategies typically set different levels based on the pre-undervoltage voltage threshold conditions of the battery in different temperature ranges, and then apply different levels of power limitation based on trigger conditions. However, this type of pre-undervoltage strategy often uses static threshold setting ranges, resulting in rigid setting levels, a coarse setting method, fixed boundary parameters, and harsh control conditions. It lacks condition awareness, and after the pre-undervoltage is triggered, the discharge power will decrease to varying degrees according to the pre-set conditions. This leads to the dual risks of excessive power suppression or insufficient protection under battery aging, inconsistent individual cell voltages, or complex operating conditions. Summary of the Invention

[0003] Therefore, the purpose of this application is to propose a method, device, electronic device, and storage medium for adjusting discharge power. It pre-divides multiple pre-undervoltage conditions, with different pre-undervoltage conditions corresponding to different power reduction ratios. It identifies the characteristics of the current operating condition and dynamically adjusts the degree of discharge power limitation based on the degree of compliance with the level range of different pre-undervoltage conditions. This more reasonably limits the discharge power, achieves maximum utilization and protection measures for the discharge end condition, and the pre-undervoltage conditions can also be dynamically updated to prevent problems such as excessive power suppression or insufficient protection.

[0004] This application provides a method for adjusting discharge power, the method comprising: acquiring the current operating parameters of a power battery; in response to a minimum single-cell voltage being less than a pre-undervoltage threshold, performing feature extraction on the current operating parameters to obtain a feature vector of the current operating condition; determining the degree of conformity between the current operating condition and at least one of the preset operating conditions based on the distance between the feature vector of the current operating condition and the cluster centers of multiple preset operating conditions; determining a target power reduction ratio based on the degree of conformity and the power reduction ratio corresponding to the preset operating conditions; and adjusting the discharge power based on the target power reduction ratio.

[0005] For example, determining the degree of conformity between the current working condition and at least one of the preset working conditions includes: obtaining the two smallest distances among the distances, denoted as the first distance and the second distance; and determining the degree of conformity between the current working condition and the first preset working condition corresponding to the first distance and the second preset working condition corresponding to the second distance based on the ratio of the first distance and the second distance.

[0006] For example, determining the degree of conformity between the current operating condition and the first preset operating condition corresponding to the first distance and the second preset operating condition corresponding to the second distance, based on the ratio of the first distance and the second distance, includes: determining that the current operating condition conforms to the first preset operating condition when the ratio is less than or equal to a first preset value; determining that the current operating condition conforms to the second preset operating condition when the ratio is greater than or equal to a second preset value; and determining that the current operating condition conforms to both the first preset operating condition and the second preset operating condition when the ratio is greater than the first preset value and less than the second preset value; wherein the first preset value and the second preset value are reciprocals of each other.

[0007] For example, determining the target power reduction ratio based on the compliance degree and the power reduction ratio corresponding to the preset operating condition includes: when the compliance degree indicates that the current operating condition matches the first preset operating condition, determining the target power reduction ratio as the first power reduction ratio corresponding to the first preset operating condition; when the compliance degree indicates that the current operating condition matches the second preset operating condition, determining the target power reduction ratio as the second power reduction ratio corresponding to the second preset operating condition; and when the compliance degree indicates that the current operating condition matches both the first and second preset operating conditions, determining the target power reduction ratio based on the first distance, the second distance, the first power reduction ratio, and the second power reduction ratio.

[0008] For example, determining the target power reduction ratio based on the first distance, the second distance, the first power reduction ratio, and the second power reduction ratio includes: determining a first product of the first power reduction ratio and the second distance, and a second product of the second power reduction ratio and the first distance; calculating a first sum of the first product and the second product, and a second sum of the first distance and the second distance; and determining the ratio of the first sum to the second sum as the target power reduction ratio.

[0009] For example, the method further includes: saving the feature vector of the current working condition, and updating the cluster centers of the multiple preset working conditions when the number of feature vectors reaches a preset number or the time interval reaches a preset time.

[0010] For example, the method further includes: determining the pre-undervoltage change trend of the preset operating condition based on the updated first cluster center and the unupdated second cluster center; and adjusting the power reduction ratio corresponding to the preset operating condition based on the pre-undervoltage change trend.

[0011] For example, determining the pre-undervoltage change trend of the preset operating condition based on the updated first cluster center and the unupdated second cluster center includes: calculating the relative change rate between the first cluster center and the second cluster center; when the relative change rate is less than or equal to a change rate threshold, determining that the pre-undervoltage change trend of the preset operating condition is that the pre-undervoltage condition is stable; when the relative change rate is greater than the change rate threshold, determining the pre-undervoltage change trend of the preset operating condition based on the change direction of the characteristic parameters of the first cluster center and the second cluster center.

[0012] For example, determining the pre-undervoltage change trend of the preset operating condition based on the change direction of the characteristic parameters of the first cluster center and the second cluster center includes: calculating the difference change magnitude of each characteristic parameter between the first cluster center and the second cluster center, wherein the direction of the difference change magnitude is determined according to the sign of the result of subtracting the second cluster center from the first cluster center; obtaining the average value of the difference change magnitude based on the difference change magnitude of each characteristic parameter; and determining the pre-undervoltage change trend of the preset operating condition based on the average value.

[0013] For example, determining the pre-undervoltage change trend of the preset operating condition based on the average value includes: when the average value is positive, determining that the pre-undervoltage change trend of the preset operating condition is an improvement in the pre-undervoltage situation; when the average value is negative, determining that the pre-undervoltage change trend of the preset operating condition is a deterioration in the pre-undervoltage situation.

[0014] For example, adjusting the power reduction ratio corresponding to the preset operating condition based on the pre-undervoltage change trend includes: when the pre-undervoltage change trend of the preset operating condition indicates an improvement in the pre-undervoltage situation, determining that the power reduction ratio corresponding to the preset operating condition remains unchanged or adjusting the power reduction ratio corresponding to the preset operating condition to increase; when the pre-undervoltage change trend of the preset operating condition indicates a deterioration in the pre-undervoltage situation, adjusting the power reduction ratio corresponding to the preset operating condition to decrease; and when the pre-undervoltage change trend of the preset operating condition indicates a stable pre-undervoltage situation, determining that the power reduction ratio corresponding to the preset operating condition remains unchanged.

[0015] For example, adjusting the power reduction ratio corresponding to the preset operating condition to increase includes: determining a first difference between a first preset value and the average value of the difference change range, and determining a first larger value between the first difference and a second preset value; determining the power reduction ratio corresponding to the preset operating condition as the ratio of the original power reduction ratio to the first larger value.

[0016] For example, adjusting the power reduction ratio corresponding to the preset operating condition to be smaller includes: determining a second larger value between the first difference and the third preset value; and determining that the power reduction ratio corresponding to the preset operating condition is the product of the original power reduction ratio and the second larger value.

[0017] For example, adjusting the discharge power based on the target power reduction ratio includes: obtaining the theoretical maximum discharge power of the battery pack; and determining the product of the theoretical maximum discharge power of the battery pack and the target power reduction ratio as the discharge power.

[0018] For example, the feature vector includes a vector consisting of at least one of the following: minimum single-cell voltage, maximum rate of decrease of single-cell voltage, number of cells below the pre-undervoltage threshold, and rate of decrease of state of charge.

[0019] For example, the preset operating conditions include an initial pre-undervoltage condition, a mid-pre-undervoltage condition, a final pre-undervoltage condition, and other conditions; wherein, the initial pre-undervoltage condition is characterized by a minimum single-cell voltage greater than a first voltage, and / or, the maximum rate of decrease of the single-cell voltage greater than a first rate, and / or, the number of single-cell cells below the pre-undervoltage voltage threshold is less than a first number, and / or, the rate of decrease of the state of charge is greater than a second rate; the mid-pre-undervoltage condition is characterized by a minimum single-cell voltage less than or equal to the first voltage and greater than a second voltage, and / or, the maximum rate of decrease of the single-cell voltage less than or equal to the first rate and greater than a third rate, and / or, the number of single-cell cells below the pre-undervoltage voltage threshold is less than a first number, and / or, the rate of decrease of the state of charge is greater than a second rate; The number is greater than or equal to the first number and less than the second number, and / or the state of charge decline rate is less than or equal to the second rate and greater than the fourth rate; the minimum single-cell voltage characterized by the pre-undervoltage end-of-term condition is less than or equal to the second voltage, and / or the maximum single-cell voltage decline rate is less than or equal to the third rate, and / or the number of single-cell cells below the pre-undervoltage voltage threshold is greater than or equal to the second number, and / or the state of charge decline rate is less than or equal to the fourth rate; wherein, the first voltage is greater than the second voltage, the first rate is greater than the third rate, the first number is less than the second number, and the second rate is greater than the fourth rate.

[0020] For example, the power reduction ratio corresponding to the initial pre-undervoltage condition is greater than the power reduction ratio corresponding to the mid-pre-undervoltage condition, the power reduction ratio corresponding to the mid-pre-undervoltage condition is greater than the power reduction ratio corresponding to the final pre-undervoltage condition, and the power reduction ratio corresponding to the other conditions is less than the power reduction ratio corresponding to the initial pre-undervoltage condition but greater than the power reduction ratio corresponding to the mid-pre-undervoltage condition.

[0021] Another embodiment of this application provides a discharge power adjustment device, the device comprising: an extraction module, configured to acquire current operating parameters of a power battery, and in response to a minimum single-cell voltage being less than a pre-undervoltage threshold, extract features from the current operating parameters to obtain a feature vector of the current operating condition; a determination module, configured to determine the degree of conformity between the current operating condition and at least one of the preset operating conditions based on the distance between the feature vector of the current operating condition and the cluster centers of multiple preset operating conditions; and an adjustment module, configured to determine a target power reduction ratio based on the degree of conformity and the power reduction ratio corresponding to the preset operating condition, and adjust the discharge power based on the target power reduction ratio.

[0022] Another embodiment of this application provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method for adjusting the discharge power.

[0023] Another embodiment of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method for adjusting discharge power.

[0024] In the above embodiments, the current operating parameters of the power battery are obtained. In response to the minimum single-cell voltage being less than the pre-undervoltage threshold, features are extracted from the current operating parameters to obtain the feature vector of the current operating condition. Based on the distance between the feature vector of the current operating condition and the cluster centers of multiple preset operating conditions, the degree of conformity between the current operating condition and at least one preset operating condition is determined. Based on the degree of conformity and the power reduction ratio corresponding to the preset operating condition, a target power reduction ratio is determined, and the discharge power is adjusted based on the target power reduction ratio. Multiple pre-undervoltage operating conditions are pre-divided, with different power reduction ratios corresponding to different pre-undervoltage operating conditions. The characteristics of the current operating condition are identified, and the degree of conformity to the level range of different pre-undervoltage operating conditions is dynamically adjusted to more reasonably limit the discharge power, achieving maximum utilization and protection measures for the end-of-discharge operating condition. Furthermore, the pre-undervoltage operating conditions can be dynamically updated to prevent problems such as excessive power suppression or insufficient protection. Attached Figure Description

[0025] Figure 1 A flowchart illustrating the method for adjusting discharge power provided in the embodiments of this application; Figure 2 A flowchart for determining the degree of conformity between the current operating condition and at least one preset operating condition, provided for embodiments of this application; Figure 3 A flowchart for determining the target power reduction ratio provided in this application embodiment; Figure 4 A flowchart of the cluster centers before and after the analysis update is provided for the implementation of this application; Figure 5 A flowchart for determining the pre-undervoltage variation trend of a preset operating condition, provided for an embodiment of this application; Figure 6 A schematic diagram illustrating the pre-undervoltage strategy provided in the embodiments of this application; Figure 7 A schematic diagram of the vehicle and cloud platform provided for an embodiment of this application; Figure 8 A schematic diagram of a discharge power adjustment device provided in an embodiment of this application; Figure 9 A block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0027] Figure 1 This is a flowchart of a method for adjusting discharge power according to an embodiment of this application.

[0028] As an example, such as Figure 1 As shown, the methods for adjusting the discharge power include: S101: Obtain the current operating parameters of the power battery. In response to the minimum single cell voltage being less than the pre-undervoltage threshold, extract features from the current operating parameters to obtain the feature vector of the current operating condition.

[0029] S102, based on the distance between the feature vector of the current working condition and the cluster centers of multiple preset working conditions, determine the degree of conformity between the current working condition and at least one preset working condition.

[0030] S103, determine the target power reduction ratio based on the compliance level and the power reduction ratio corresponding to the preset operating conditions, and adjust the discharge power based on the target power reduction ratio.

[0031] For example, the discharge power adjustment method of this application is executed online in real time. The current operating parameters of the power battery include, but are not limited to, data such as the voltage of all individual cells and the state of charge (SOC). In response to the minimum individual cell voltage being less than a pre-undervoltage threshold, it can be understood that this application sets a pre-undervoltage individual cell voltage threshold. When the power battery pack is in a discharge state and the minimum individual cell voltage is less than this threshold, it is determined that the power battery has entered the end-of-discharge condition. In other words, the discharge power adjustment method of this application is applied to the end-of-discharge condition of the power battery. Feature extraction is performed based on the current operating parameters to obtain a feature vector of the current condition. The feature vector includes multiple feature parameters, such as the minimum individual cell voltage, the rate of SOC decrease, etc.

[0032] For example, the feature vector of the current operating condition is compared with the cluster centers of multiple preset operating conditions to determine the degree of conformity between the current operating condition and at least one preset operating condition. It can be understood that the closer the feature vector is to the cluster center, the more the current operating condition conforms to the preset operating condition. A target power reduction ratio is determined based on the degree of conformity and the power reduction ratio corresponding to the preset operating condition. Finally, the discharge power is adjusted based on the target power reduction ratio.

[0033] The pre-undervoltage strategy of this application uses a clustering algorithm to classify operating conditions and identify the degree of compliance of operating conditions online. It has the advantages of operating condition perception and setting methods that are more in line with actual operating conditions. It dynamically adjusts the degree of limiting discharge power according to the current degree of compliance of operating conditions, which solves the problem of traditional methods using static thresholds to set level ranges and rigidly limiting discharge power according to the set level.

[0034] The following example illustrates how to divide preset working conditions.

[0035] As an example, complete historical operating condition data of the battery at the end of its discharge cycle is collected to form a training sample dataset. The richness of the historical data will affect the optimization effect of this strategy. For example, data on the power battery from its factory state to the end of 300 discharge cycles can be collected, including but not limited to data on the voltage and SOC of all individual cells, as the initial sample dataset. The historical operating condition data at the end of each discharge cycle in the sample dataset is divided into segments of fixed time window length, and each segment is taken as an independent operating condition segment sample. At each sampling moment of the historical operating condition segment, the operating condition feature parameters of the past time window length are calculated to obtain the feature parameter sample data [x]. 11 x 12 , ..., x 1m ], [x 21 x 22 , ..., x 2m ], ..., [x] n1 x n2 , ..., xnm ], where m is the number of feature parameters and n is the sequence number of historical working condition segments.

[0036] In one embodiment, the collected training dataset is divided into independent working condition sample data with a fixed time window length of 1 second.

[0037] As an example, the feature vector consists of at least one of the following: minimum cell voltage, maximum rate of decrease of cell voltage, number of cells below the pre-undervoltage threshold, and rate of decrease of state of charge.

[0038] It is understood that the characteristic parameters include at least one of the following: minimum single-cell voltage, maximum rate of decrease of single-cell voltage, number of cells below the pre-undervoltage threshold, and rate of decrease of state of charge. It can be one or both of these. This application does not limit the number of characteristic parameters. The following explanation uses the example of characteristic parameters including minimum single-cell voltage, maximum rate of decrease of single-cell voltage, number of cells below the pre-undervoltage threshold, and rate of decrease of state of charge. In this case, m=4.

[0039] Next, the feature parameters of each work condition segment are preprocessed by normalization to avoid the small-dimensional features being masked during data analysis due to inconsistent feature parameter units. The collected training data is preprocessed using Min-Max normalization. Specifically, for example, for the m-th feature parameter x of the i-th work condition segment in the dataset... im Normalization is performed to obtain the normalized data x. im The calculation formula is as follows:

[0040] Where m is the number of characteristic parameters and n is the sequence number of the working condition segment.

[0041] For example, clustering algorithms can be used for classification, such as K-means clustering, which classifies data by calculating the degree of similarity between samples. This results in data within the same class having high feature similarity, while data in different classes show significant differences. Specific steps include: First, determine the number of clusters r to be obtained. The value of r is generally greater than or equal to 4. That is, the cluster analysis generally has more than 4 categories so that the differences in the feature parameters of the classification are obvious enough and the clustering effect is good enough.

[0042] When using the K-means clustering algorithm, r data points are randomly selected from the sample data as the initial cluster centers. =[ , , ..., ], =[ , , ..., ], =[ , , ..., ], ..., =[ , , ..., ] .

[0043] Calculate the distances between the feature parameters of all working condition segments in the sample and different cluster centers, and group the samples according to the nearest neighbor rule, assigning them to different θm(k) cluster domains, where k is the number of iterations. Then adjust the cluster centers according to the following formula:

[0044] in, This represents the new cluster center of the m-th cluster after the (k+1)-th iteration. This represents the set of all sample points belonging to the m-th cluster at the k-th iteration. This represents the total number of sample points in the m-th cluster.

[0045] If the iteration reaches the cluster centers at step k+1... With the cluster centers iterated to the k-th step If (k) are not equal, continue iteratively calculating and adjusting the cluster centers until the change in cluster centers converges to less than the prediction threshold. At this point, the classification is considered stable, and the cluster centers for all working conditions are finally obtained. =[ , , ..., ], =[ , , ..., ], =[ , , ..., ], ..., =[ , , ..., ] .

[0046] The results of cluster center analysis are subjected to an inverse Min-Max normalization transformation to restore the feature parameters to their original dimensions, enabling analysis of the characteristics of each cluster center and the pre-undervoltage clustering conditions they represent. For example, for the m-th feature parameter c in the i-th cluster center... im Perform the inverse Min-Max normalization transform and calculate using the following formula:

[0047] Where m is the number of characteristic parameters and n is the sequence number of the working condition segment.

[0048] Of course, clustering algorithms can replace other types of clustering algorithms, such as fuzzy C-clustering.

[0049] As an example, the preset operating conditions include the initial pre-undervoltage condition, the middle pre-undervoltage condition, the final pre-undervoltage condition, and other conditions; Among them, the initial pre-undervoltage condition is characterized by the minimum single cell voltage being greater than the first voltage, and / or the maximum rate of decrease of single cell voltage being greater than the first rate, and / or the number of single cells below the pre-undervoltage voltage threshold being less than the first number, and / or the rate of decrease of state of charge being greater than the second rate. The pre-undervoltage mid-term operating condition characterizes the minimum single cell voltage as less than or equal to the first voltage and greater than the second voltage, and / or the maximum rate of decrease of single cell voltage as less than or equal to the first rate and greater than the third rate, and / or the number of cells below the pre-undervoltage voltage threshold as greater than or equal to the first number and less than the second number, and / or the rate of decrease of state of charge as less than or equal to the second rate and greater than the fourth rate. The pre-undervoltage end-of-life condition characterizes the minimum single-cell voltage as less than or equal to the second voltage, and / or the maximum rate of decrease of single-cell voltage as less than or equal to the third rate, and / or the number of cells below the pre-undervoltage threshold as greater than or equal to the second number, and / or the rate of decrease of state of charge as less than or equal to the fourth rate. Among them, the first voltage is greater than the second voltage, the first speed is greater than the third speed, the first number is less than the second number, and the second speed is greater than the fourth speed.

[0050] For example, the number of clusters r obtained from clustering can be 4, meaning that iteration until convergence yields 4 stable cluster centers for the operating condition sample data. Analyzing the characteristic parameters of these cluster centers reveals the following: Cluster centers with higher minimum single-cell voltage, larger maximum rate of voltage drop, fewer cells below the pre-undervoltage threshold, and a larger rate of SOC decline; these cluster centers correspond to the characteristics of the initial pre-undervoltage operating condition. Cluster centers with moderate minimum single-cell voltage, moderate maximum rate of voltage drop, moderate number of cells below the pre-undervoltage threshold, and a moderate rate of SOC decline; these cluster centers correspond to the characteristics of the mid-pre-undervoltage operating condition. Cluster centers with lower minimum single-cell voltage, smaller maximum rate of voltage drop, more cells below the pre-undervoltage threshold, and a smaller rate of SOC decline; these cluster centers correspond to the characteristics of the late pre-undervoltage operating condition. A class of cluster centers with no significant trend in characteristic parameter changes corresponds to other operating conditions where the pre-undervoltage development is relatively mild.

[0051] It should be noted that when dividing the pre-undervoltage initial operating condition, pre-undervoltage mid-operating condition, pre-undervoltage final operating condition, and other operating conditions, the above four characteristic parameters can be used, or several of them can be used. For example, the preset operating conditions can be divided using only the minimum single-cell voltage and the maximum rate of decrease of single-cell voltage.

[0052] Based on the characteristic parameters of different cluster centers obtained from clustering, the severity of the cluster categories is analyzed, and initial power reduction ratios are set for different categories. Specifically, the initial power reduction ratio for c1 is set as f1, for c2 as f2, and so on. r The corresponding initial power reduction ratio is f r .

[0053] As an example, the power reduction ratio corresponding to the initial pre-undervoltage condition is greater than that corresponding to the middle pre-undervoltage condition, the power reduction ratio corresponding to the middle pre-undervoltage condition is greater than that corresponding to the final pre-undervoltage condition, and the power reduction ratio corresponding to other conditions is less than that corresponding to the initial pre-undervoltage condition but greater than that corresponding to the middle pre-undervoltage condition.

[0054] For example, if the number of clusters obtained by clustering is r=4, the cluster center characteristic parameters can be analyzed to obtain the cluster center c1 for the initial pre-undervoltage condition, c2 for the mid-pre-undervoltage condition, c3 for the final pre-undervoltage condition, and c4 for other conditions. According to the severity of the pre-undervoltage condition, the initial power reduction ratio f1=0.7 for c1, f2=0.4 for c2, f3=0.1 for c3, and f4=0.6 for c4.

[0055] After the cloud platform analyzes the results, it sends the cluster center parameters and the corresponding power reduction ratio determined by the cluster analysis to the vehicle through a certain communication connection. The vehicle stores the above data in the controller's memory for real-time calculation and retrieval.

[0056] During real-time operation, the vehicle continuously collects current operating data such as the voltage and SOC of all individual cells in the battery pack. When the minimum cell voltage is greater than or equal to the set pre-undervoltage threshold, the theoretical maximum discharge power capability of the vehicle's battery pack is determined based on the current battery parameters, and normal discharge operation is initiated. When the minimum cell voltage is lower than the set pre-undervoltage threshold, the pre-undervoltage control strategy is triggered in response to the minimum cell voltage being lower than the pre-undervoltage threshold, and the target power reduction ratio is determined.

[0057] If the vehicle battery has experienced the full time window length since being triggered from the pre-undervoltage condition at the current sampling time, then the feature vector [x1, x2, ..., x] of the condition segment in the past time window is calculated.m ] .

[0058] Calculate the distances from the feature vectors of the current operating condition segment to different cluster centers, and calculate the feature parameter values ​​[x1, x2, ..., x] according to the following formula. m Distance to r cluster centers :

[0059] Where j = 1, 2, ..., r corresponds to working condition r. This distance is the Euclidean distance.

[0060] After obtaining the distances from the feature vectors of the current working condition segment to different cluster centers, the cluster category of the current working condition is determined.

[0061] As an example, such as Figure 2 As shown, determining the degree of conformity between the current operating condition and at least one preset operating condition includes: S201, obtain the two smallest distances, denoted as the first distance and the second distance.

[0062] S202, based on the ratio of the first distance and the second distance, determine the degree of conformity between the current working condition and the first preset working condition corresponding to the first distance and the second preset working condition corresponding to the second distance.

[0063] For example, the two smallest distance values ​​among all distances can be selected; for instance, the calculation results include d1 to d2. r Compare the results and find the smallest distance value d between the cluster centers of the p-th and q-th clusters. p and d q Let d be the first distance. p Second distance d q Then, based on the ratio of the first distance to the second distance, the degree of conformity between the current working condition and the first preset working condition corresponding to the first distance and the second preset working condition corresponding to the second distance is determined.

[0064] Of course, you can directly select the preset working condition with the smallest distance as the category of the current working condition.

[0065] As an example, based on the ratio of a first distance to a second distance, the degree of conformity between the current operating condition and the first preset operating condition corresponding to the first distance and the second preset operating condition corresponding to the second distance is determined, including: When the ratio is less than or equal to the first preset value, it is determined that the current working condition matches the first preset working condition; When the ratio is greater than or equal to the second preset value, it is determined that the current working condition matches the second preset working condition; When the ratio is greater than the first preset value and less than the second preset value, it is determined that the current working condition is consistent with the first preset working condition and the second preset working condition. The first preset value and the second preset value are reciprocals of each other.

[0066] For example, the first preset value can be 0.1, and the second preset value is the reciprocal of the first preset value, i.e., the second preset value is 10. If the ratio of the first distance to the second distance is less than or equal to the first preset value, it means that the numerator is much smaller than the denominator, and the current operating condition is determined to be uniquely consistent with the first preset operating condition corresponding to the first distance. Similarly, if the ratio of the first distance to the second distance is greater than or equal to the second preset value, for example, greater than or equal to 10, it means that the numerator is much larger than the denominator, and the current operating condition is determined to be uniquely consistent with the second preset operating condition corresponding to the second distance. If the ratio of the first distance to the second distance is between the two, then the current operating condition is also between the first preset operating condition and the second preset operating condition.

[0067] For example, if the first distance d p ≤0.1 d q If d q ≤0.1 d p If the current working condition is completely classified as belonging to the q-th cluster, then the current working condition segment is determined to be between the p-th and q-th clusters.

[0068] As an example, the target power reduction ratio is determined based on the degree of compliance and the power reduction ratio corresponding to the preset operating conditions, including: When the degree of conformity indicates that the current operating condition matches the first preset operating condition, the target power reduction ratio is determined to be the first power reduction ratio corresponding to the first preset operating condition; When the degree of conformity indicates that the current operating condition matches the second preset operating condition, the target power reduction ratio is determined to be the second power reduction ratio corresponding to the second preset operating condition; When the degree of conformity indicates that the current operating condition matches the first preset operating condition and the second preset operating condition, the target power reduction ratio is determined based on the first distance, the second distance, the first power reduction ratio, and the second power reduction ratio.

[0069] For example, if the current operating condition matches only a single operating condition, the target power reduction ratio can be the power reduction ratio corresponding to the preset operating condition. If the current operating condition is between two operating conditions, the target power reduction ratio is obtained by comprehensively processing the corresponding power reduction ratios of these two operating conditions.

[0070] As an example, such as Figure 3 As shown, the target power reduction ratio is determined based on the first distance, the second distance, the first power reduction ratio, and the second power reduction ratio, including: S301, determine the first product of the first power reduction ratio and the second distance, the second power reduction ratio and the second product of the first distance.

[0071] S302, calculate the first sum of the first product and the second product, and the second sum of the first distance and the second distance.

[0072] S303, determine the ratio of the first sum and the second sum as the target power reduction ratio.

[0073] For example, if the battery's current operating condition is entirely within the p-th type of operating condition, the power reduction ratio of the current pre-undervoltage can be determined based on the data stored in the memory, and the target power reduction ratio f = fp can be determined. If the battery's current operating condition is entirely within the q-th type of operating condition, the power reduction ratio of the current pre-undervoltage can be determined based on the data stored in the memory, and the target power reduction ratio f = fq.

[0074] For example, if the current operating condition of the battery belongs to either the p-th or q-th cluster, a weighted average method can be applied to calculate the corresponding power reduction ratio. and To smooth the process, the target power reduction ratio f at the current moment is determined using the following formula:

[0075] As an example, adjusting the discharge power based on the target power reduction ratio includes: Obtain the theoretical maximum discharge power of the battery pack; The product of the theoretical maximum discharge power of the battery pack and the target power reduction ratio is determined as the discharge power.

[0076] For example, the theoretical maximum discharge power P of the vehicle battery pack at the current moment can be found based on the current battery parameters. map The current allowable discharge power of the battery is P = P map f, This is used to limit the battery pack's discharge capacity in real time while the vehicle is operating.

[0077] This application utilizes historical data on electric vehicle driving conditions to obtain the minimum single-cell voltage, maximum rate of voltage drop, number of cells below the pre-undervoltage threshold, and rate of charge degradation of the battery at the current moment. It then applies a driving condition identification algorithm to cluster and classify the current and historical driving conditions of the electric vehicle into pre-undervoltage initial stage, pre-undervoltage mid-stage, pre-undervoltage final stage, and other characteristic stages. Different power reduction coefficients are assigned to each stage based on its severity. By identifying and clustering the characteristic parameters of the current driving condition to determine the power reduction ratio, the current allowable discharge power is adjusted to the target allowable discharge power. Compared to the traditional strategy of using only the minimum single-cell voltage to determine the discharge power, multi-parameter clustering more reasonably reflects the complexity of the driving condition and is suitable for cell inconsistencies. Effectively utilizing historical data to identify the current driving condition and determine the appropriate power reduction ratio results in a smoother change in the discharge power at the end of the power battery discharge, improving the user's driving experience.

[0078] As an example, the method for adjusting discharge power also includes: saving the feature vector of the current operating condition, and updating the cluster centers of multiple preset operating conditions when the number of feature vectors reaches a preset number or the time interval reaches a preset time.

[0079] For example, after the battery calculates the characteristic parameters of the operating condition segment, it uploads the results to the cloud platform through a certain communication connection and stores them in the historical operating condition sample dataset for offline data analysis by the cloud platform. When a fixed time period is reached or the amount of data accumulates to a certain condition, the previous cluster center can be used as the initial cluster center for the current clustering, and the clustering algorithm can be used again to classify the data, so that the cluster categories are more consistent with the current health status of the battery.

[0080] In one embodiment, the vehicle continuously stores characteristic parameter data of pre-undervoltage operating condition segments into the controller's memory. When the vehicle is in sleep or standby mode, the data for each pre-undervoltage operating condition segment is uploaded to the cloud platform and recorded in the historical sample database. If the vehicle can be considered to have undergone 50 discharge cycles when the cumulative discharge amount reaches 50 times the rated capacity, the oldest 50 cycles of pre-undervoltage operating condition data in the sample dataset are cleared, and the pre-undervoltage strategy data for these 50 discharge cycles are added to form a new sample dataset. Using the latest dataset, the previous cluster center is used as the initial cluster center for this time, and the clustering algorithm is restarted. Offline analysis is performed to obtain new cluster centers, making the clustering conditions more reasonable and better adapted to the current actual state of the battery.

[0081] The new cluster centers after re-clustering are analyzed and compared with the old cluster centers to analyze the effect of the discharge power adjustment strategy and determine whether the actual operating conditions of the pre-undervoltage have changed.

[0082] As an example, such as Figure 4 As shown, the method for adjusting the discharge power also includes: S401, based on the updated first cluster center and the unupdated second cluster center, determine the pre-undervoltage change trend of the preset working condition.

[0083] S402 adjusts the power reduction ratio corresponding to the preset operating conditions based on the pre-undervoltage change trend.

[0084] For example, the new cluster centers after re-clustering are analyzed and compared with the previous old cluster centers to analyze the effect of the discharge power adjustment strategy and determine whether the actual pre-undervoltage operating condition has changed. The updated cluster centers are designated as the first cluster centers, and the unupdated cluster centers as the second cluster centers. The power reduction ratio corresponding to the preset operating condition is further adjusted based on the pre-undervoltage change trend of the preset operating condition.

[0085] As an example, based on the updated first cluster centers and the unupdated second cluster centers, the pre- and undervoltage change trends of the preset operating conditions are determined, including: Calculate the relative rate of change between the first cluster center and the second cluster center; When the relative rate of change is less than or equal to the rate of change threshold, the pre-undervoltage change trend of the preset working condition is determined to be that the pre-undervoltage condition is stable. When the relative rate of change is greater than the rate of change threshold, the pre-undervoltage change trend of the preset working condition is determined based on the change direction of the characteristic parameters of the first cluster center and the second cluster center.

[0086] For example, one can determine whether a clustering condition has improved by judging the relative rate of change between the old and new cluster centers for a certain clustering scenario. First, the distance Δd between the old and new cluster centers of the i-th cluster is calculated. i As shown in the following formula:

[0087] in, This represents the value of the j-th dimension feature of the new cluster center of the i-th class. This represents the value of the j-th dimension feature of the old cluster center of the i-th class.

[0088] Next, we calculate the relative rate of change R between the old and new cluster centers of the i-th type. i As shown in the following formula:

[0089] in, It is the norm of the old cluster centers.

[0090] For example, when the relative rate of change is less than or equal to a threshold, such as 5%, the operating condition is considered stable and has neither improved nor worsened. When the relative rate of change is greater than the threshold, such as 5%, it is necessary to further determine whether the operating condition has improved or worsened. Based on the direction of change of the characteristic parameters of the first and second cluster centers, the pre-undervoltage change trend of the preset operating condition is further determined.

[0091] As an example, such as Figure 5 As shown, based on the changing directions of characteristic parameters of the first and second cluster centers, the pre- and undervoltage changing trends of the preset operating conditions are determined, including: S501, calculate the magnitude of the difference in each characteristic parameter between the first cluster center and the second cluster center, wherein the direction of the magnitude of the difference is determined by the sign of the result of subtracting the second cluster center from the first cluster center.

[0092] S502, based on the magnitude of the difference change of each feature parameter, obtain the average value of the difference change magnitude.

[0093] S503 determines the pre-undervoltage change trend of preset working conditions based on the average value.

[0094] For example, the magnitude of the difference can be obtained by subtracting the feature parameter corresponding to the second cluster center from a feature parameter of the first cluster center, and then dividing the difference by the feature parameter corresponding to the second cluster center. This magnitude of the difference is understood to be a percentage, used to characterize the degree of change. Furthermore, this magnitude of the difference has a direction, including positive and negative directions. The direction of the magnitude of the difference is determined by the sign of the result of subtracting the second cluster center from the first cluster center. Specifically, if the subtraction of the feature parameter of the first cluster center from the feature parameter of the second cluster center is positive, the sign of the magnitude of the difference is positive; if the subtraction is negative, the sign of the magnitude of the difference is negative. This process is performed on each feature parameter.

[0095] For example, the average value of the difference change amplitude of each characteristic parameter is obtained by summing and averaging the difference change amplitudes. The summation process is a signed summation process, and finally the average value of the difference change amplitude is obtained. The average value of the difference change amplitude is used to further determine the pre-undervoltage change trend of the preset working condition.

[0096] As an example, determining the pre-undervoltage variation trend under preset operating conditions based on average values ​​includes: When the average value is positive, the pre-undervoltage change trend of the preset working condition is determined to be an improvement in the pre-undervoltage situation; When the average value is negative, the pre-undervoltage change trend of the preset working condition is determined to be a deterioration of the pre-undervoltage situation.

[0097] For example, comparing the feature parameter values ​​in the old and new cluster centers. The direction and magnitude of the change are determined as follows: if the change is in the direction of reducing pre-premium / under-premium voltage, the sign bit before the change magnitude is positive; if the change is in the direction of increasing pre-premium / under-premium voltage, the sign bit before the change magnitude is negative. The average of the change magnitudes after processing all characteristic parameters is then calculated. A positive mean indicates that the pre-undervoltage situation has been alleviated after the discharge power control strategy takes effect, meaning the pre-undervoltage situation has improved. A negative mean indicates that the pre-undervoltage situation has worsened after the discharge power control strategy takes effect.

[0098] As an example, adjusting the power reduction ratio corresponding to the preset operating conditions based on the pre-undervoltage change trend includes: If the pre- and undervoltage change trend under the preset operating condition is that the pre- and undervoltage situation is improving, determine whether the power reduction ratio corresponding to the preset operating condition remains unchanged or adjusts the power reduction ratio corresponding to the preset operating condition to be larger. When the pre-voltage change trend of the preset operating condition is that the pre-voltage situation is worsening, the power reduction ratio corresponding to the preset operating condition is adjusted to be smaller. If the pre- and undervoltage change trend of the preset operating condition is stable, the power reduction ratio corresponding to the preset operating condition is determined to remain unchanged.

[0099] For example, the power reduction ratio for the corresponding category is adjusted based on the analysis results of changes in clustering. If the new cluster centers tend to worsen pre-undervoltage compared to the old cluster centers, the corresponding power reduction ratio is further reduced to further limit the output of discharge power and mitigate the development of pre-undervoltage. If the new cluster centers remain stable compared to the old cluster centers, the previous power reduction ratio is maintained. If the new cluster centers tend to reduce pre-undervoltage compared to the old cluster centers, the previous power reduction ratio can be maintained or slightly increased to slightly relax the restriction on discharge power, allowing the battery to discharge more even with reduced pre-undervoltage.

[0100] As an example, adjusting the power reduction ratio corresponding to the preset operating condition to be larger includes: determining the first difference between the first preset value and the average value of the difference change range, and determining the first larger value between the first difference and the second preset value; determining the power reduction ratio corresponding to the preset operating condition as the ratio of the original power reduction ratio to the first larger value.

[0101] For example, the first preset value can be 1, and the average value of the difference change is recorded as 1. The first difference is 1- The second preset value can be 0.95. The larger of the first difference and the second preset value is determined. The power reduction ratio corresponding to the preset operating condition is determined as the ratio of the original power reduction ratio to the larger of the first preset value. The specific expression is as follows:

[0102] in, The original power reduction ratio of the cluster centers of the i-th class. This represents the power reduction ratio corresponding to the cluster center of the i-th class after adjustment.

[0103] As an example, adjusting the power reduction ratio corresponding to the preset operating condition to be smaller includes: determining the second larger value between the first difference and the third preset value; and determining that the power reduction ratio corresponding to the preset operating condition is the product of the original power reduction ratio and the second larger value.

[0104] For example, the third preset value can be 0.9, and the second larger value between the first difference and the third preset value is determined; the power reduction ratio corresponding to the preset operating condition is determined to be the product of the original power reduction ratio and the second larger value, and the specific expression is as follows:

[0105] In one embodiment, the relative rate of change R of the cluster centers of the i-th class is... i If the percentage is less than or equal to 5%, then the operating condition is considered stable, and the newly set power reduction ratio for the i-th type is determined. Power reduction ratio compared to the old setting remain unchanged. If the relative change rate of the cluster centers of the i-th class is greater than 5% and the mean change amplitude after processing is... If the value is positive, the pre-undervoltage condition is alleviated. A fine adjustment is made to the old power reduction ratio to obtain the new power reduction ratio, calculated using the following formula:

[0106] If the relative change rate of the cluster centers of the i-th class is greater than 5% and the mean change amplitude after processing is... If the value is negative, the undervoltage condition is aggravated. The power reduction ratio is further reduced from the old setting to obtain a new setting, calculated using the following formula:

[0107] After the cloud platform analyzes and calculates the new cluster centers and power reduction ratio, it sends the results to the vehicle end through a certain communication connection. The vehicle end stores the above data in the controller's memory for real-time calculation and retrieval during subsequent discharge conditions.

[0108] After collecting sufficient historical operating condition data, this application performs offline analysis and clustering algorithm to identify the operating condition center and dynamically adjust the degree of restriction. This avoids the shortcomings of traditional technology, such as fixed boundary parameters, rigid control conditions, and inability to dynamically adjust with battery aging, individual cell inconsistency, or complex operating conditions, thus preventing excessive power suppression or insufficient protection.

[0109] Figure 6 This is a schematic diagram of a pre-undervoltage strategy according to an embodiment of this application.

[0110] like Figure 6 As shown, by collecting and analyzing historical battery operating condition data, offline data analysis is performed on a cloud platform. Operating condition identification is applied to extract feature parameters from operating condition segments, and the historical driving conditions of electric vehicles are clustered. The resulting clusters are identified based on their pre-undervoltage operating condition characteristics according to the cluster feature parameters. The initial discharge power reduction ratio is determined based on the severity. The cluster center feature parameters and corresponding power reduction ratios analyzed by the cloud platform are sent to the vehicle for storage. On the vehicle, the theoretical maximum discharge power capacity of the battery pack is retrieved in real time according to the current battery pack parameters. The degree to which the vehicle's current operating condition matches different cluster categories is determined, and the current power reduction ratio is determined. Based on the vehicle's theoretical maximum discharge power and the limited discharge power ratio of the current pre-undervoltage operating condition category, the current allowable output power of the vehicle's battery pack can be determined. The vehicle can dynamically adjust the output power of the battery pack within this limit, reasonably limit the power, protect the battery state, smooth the power output, and improve the user experience. As the number of battery operating cycles increases and historical operating condition data is collected, the cloud platform can perform offline data analysis again, re-use clustering algorithms to divide the clusters and determine the power reduction ratio, and transmit it to the vehicle end, so that the discharge power adjustment strategy is more in line with the current state and operating characteristics of the vehicle battery pack.

[0111] Figure 7 This is a schematic diagram of the structure of a vehicle and a cloud platform according to one embodiment of this application. Figure 7 As shown, the cloud platform includes a data analysis center and a database. The database stores historical battery operating condition data. The data analysis center is used to extract feature parameters from operating condition segments for application operating condition identification, cluster the historical driving conditions of electric vehicles, update the cluster centers, and adjust the power reduction ratio based on the update level. The updated cluster centers and power reduction ratio are then provided to the vehicle for online application. The vehicle implements a pre-undervoltage discharge strategy based on the current real-time operating data.

[0112] This application also proposes a discharge power adjustment device.

[0113] As an example, such as Figure 8As shown, the discharge power adjustment device includes: an extraction module 801, used to acquire the current operating parameters of the power battery, and in response to the minimum single cell voltage being less than a pre-undervoltage threshold, to extract features from the current operating parameters to obtain a feature vector of the current operating condition; a determination module 802, used to determine the degree of conformity between the current operating condition and at least one preset operating condition based on the distance between the feature vector of the current operating condition and the cluster centers of multiple preset operating conditions; and an adjustment module 803, used to determine a target power reduction ratio based on the degree of conformity and the power reduction ratio corresponding to the preset operating condition, and to adjust the discharge power based on the target power reduction ratio.

[0114] This application also proposes a computer-readable storage medium.

[0115] In this embodiment, a computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, it implements the steps of the above-described method for adjusting the discharge power.

[0116] Figure 9 A block diagram of an electronic device provided in an embodiment of this application.

[0117] This application provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method for adjusting discharge power.

[0118] like Figure 9 As shown, for ease of understanding, embodiments of this application illustrate a specific electronic device.

[0119] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0120] like Figure 9 As shown, the device includes a computing unit 901, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 902 or a computer program loaded into a random access memory (RAM) 903 from a storage unit 908. The RAM 903 may also store various programs and data required for the operation of the electronic device. The computing unit 901, ROM 902, and RAM 903 are interconnected via a bus 904. An input / output (I / O) interface 905 is also connected to the bus 904.

[0121] Multiple components in the electronic device are connected to the I / O interface 905. These components include: an input unit 906, such as a keyboard or mouse; an output unit 907, such as various types of displays or speakers; a storage unit 908, such as a hard disk or optical disk; and a communication unit 909, such as a network interface card (NIC), a modem, or a wireless transceiver. The communication unit 909 allows the electronic device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0122] The computing unit 901 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 901 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 901 performs the various methods described above, such as the discharge power adjustment method. For example, in some embodiments, the discharge power adjustment method can be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 908. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device via ROM 902 and / or communication unit 909. When the computer program is loaded into RAM 903 and executed by the computing unit 901, the discharge power adjustment method described above can be performed. Alternatively, in other embodiments, the computing unit 901 can be configured to perform the discharge power adjustment method by any other suitable means (e.g., by means of firmware).

[0123] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this application, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0124] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0125] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0126] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0127] Furthermore, the terms "first," "second," etc., used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this application can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this application, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly and specifically defined in the embodiments.

[0128] In this application, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific implementation.

[0129] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0130] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for adjusting discharge power, characterized in that, The method includes: The current operating parameters of the power battery are obtained. In response to the minimum single cell voltage being less than the pre-undervoltage threshold, the current operating parameters are used to extract features to obtain the feature vector of the current operating condition. Based on the distance between the feature vector of the current working condition and the cluster centers of multiple preset working conditions, the degree of conformity between the current working condition and at least one of the preset working conditions is determined. The target power reduction ratio is determined based on the degree of compliance and the power reduction ratio corresponding to the preset operating conditions, and the discharge power is adjusted based on the target power reduction ratio.

2. The method for adjusting discharge power according to claim 1, characterized in that, Determining the degree of conformity between the current operating condition and at least one of the preset operating conditions includes: The two smallest distances among the given distances are denoted as the first distance and the second distance. Based on the ratio of the first distance to the second distance, the degree of conformity between the current working condition and the first preset working condition corresponding to the first distance and the second preset working condition corresponding to the second distance is determined.

3. The method for adjusting discharge power according to claim 2, characterized in that, Determining the degree of conformity between the current operating condition and the first preset operating condition corresponding to the first distance and the second preset operating condition corresponding to the second distance, based on the ratio of the first distance and the second distance, includes: When the ratio is less than or equal to a first preset value, it is determined that the current operating condition matches the first preset operating condition. When the ratio is greater than or equal to the second preset value, it is determined that the current operating condition matches the second preset operating condition; When the ratio is greater than the first preset value and less than the second preset value, it is determined that the current operating condition is consistent with the first preset operating condition and the second preset operating condition; The first preset value and the second preset value are reciprocals of each other.

4. The method for adjusting discharge power according to claim 3, characterized in that, Determining the target power reduction ratio based on the compliance level and the power reduction ratio corresponding to the preset operating condition includes: When the degree of conformity indicates that the current operating condition matches the first preset operating condition, the target power reduction ratio is determined to be the first power reduction ratio corresponding to the first preset operating condition; When the degree of conformity indicates that the current operating condition matches the second preset operating condition, the target power reduction ratio is determined to be the second power reduction ratio corresponding to the second preset operating condition; When the degree of conformity indicates that the current operating condition is consistent with the first preset operating condition and the second preset operating condition, the target power reduction ratio is determined based on the first distance, the second distance, the first power reduction ratio, and the second power reduction ratio.

5. The method for adjusting discharge power according to claim 4, characterized in that, Determining the target power reduction ratio based on the first distance, the second distance, the first power reduction ratio, and the second power reduction ratio includes: Determine the first product of the first power reduction ratio and the second distance, and the second product of the second power reduction ratio and the first distance; Calculate the first sum of the first product and the second product, and the second sum of the first distance and the second distance; The ratio of the first sum to the second sum is determined as the target power reduction ratio.

6. The method for adjusting discharge power according to claim 1, characterized in that, The method further includes: Save the feature vector of the current working condition, and update the cluster centers of the multiple preset working conditions when the number of feature vectors reaches a preset number or the time interval reaches a preset time.

7. The method for adjusting discharge power according to claim 1 or 6, characterized in that, The method further includes: Based on the updated first cluster center and the unupdated second cluster center, the pre-undervoltage change trend of the preset working condition is determined; The power reduction ratio corresponding to the preset operating condition is adjusted based on the pre-undervoltage change trend.

8. The method for adjusting discharge power according to claim 7, characterized in that, The step of determining the pre-undervoltage change trend of the preset operating condition based on the updated first cluster centers and the unupdated second cluster centers includes: Calculate the relative rate of change between the first cluster center and the second cluster center; When the relative rate of change is less than or equal to the rate of change threshold, the pre-undervoltage change trend of the preset working condition is determined to be a stable pre-undervoltage condition. When the relative rate of change is greater than the rate of change threshold, the pre-undervoltage change trend of the preset working condition is determined based on the change direction of the characteristic parameters of the first cluster center and the second cluster center.

9. The method for adjusting discharge power according to claim 8, characterized in that, The step of determining the pre-undervoltage change trend of the preset operating condition based on the change direction of the characteristic parameters of the first cluster center and the second cluster center includes: Calculate the magnitude of the difference in each feature parameter between the first cluster center and the second cluster center, wherein the direction of the magnitude of the difference is determined based on the sign of the result of subtracting the second cluster center from the first cluster center; Based on the magnitude of the difference change of each feature parameter, the average value of the difference change magnitude is obtained; The pre-undervoltage change trend of the preset operating condition is determined based on the average value.

10. The method for adjusting discharge power according to claim 9, characterized in that, The step of determining the pre-undervoltage change trend of the preset operating condition based on the average value includes: When the average value is positive, the pre-undervoltage change trend of the preset operating condition is determined to be an improvement in the pre-undervoltage situation; When the average value is negative, the pre-undervoltage change trend of the preset operating condition is determined to be a deterioration of the pre-undervoltage situation.

11. The method for adjusting the discharge power according to any one of claims 8-10, characterized in that, The adjustment of the power reduction ratio corresponding to the preset operating condition based on the pre-undervoltage change trend includes: If the pre-undervoltage change trend of the preset operating condition is that the pre-undervoltage situation is improving, determine whether the power reduction ratio corresponding to the preset operating condition remains unchanged or adjusts the power reduction ratio corresponding to the preset operating condition to be larger. If the pre-undervoltage change trend of the preset operating condition is that the pre-undervoltage situation is worsening, the power reduction ratio corresponding to the preset operating condition will be adjusted to be smaller. If the pre-undervoltage change trend of the preset operating condition is stable, the power reduction ratio corresponding to the preset operating condition is determined to remain unchanged.

12. The method for adjusting discharge power according to claim 11, characterized in that, The adjustment of the power reduction ratio corresponding to the preset operating condition to be increased includes: Determine a first difference between a first preset value and the average value of the difference variation range, and determine a first larger value between the first difference and a second preset value; The power reduction ratio corresponding to the preset operating condition is determined as the ratio of the original power reduction ratio to the first larger value.

13. The method for adjusting discharge power according to claim 12, characterized in that, The adjustment of the power reduction ratio corresponding to the preset operating condition to a smaller value includes: Determine the second larger value between the first difference and the third preset value; The power reduction ratio corresponding to the preset operating condition is determined to be the product of the original power reduction ratio and the second larger value.

14. The method for adjusting discharge power according to claim 1, characterized in that, The adjustment of the discharge power based on the target power reduction ratio includes: Obtain the theoretical maximum discharge power of the battery pack; The product of the theoretical maximum discharge power of the battery pack and the target power reduction ratio is determined as the discharge power.

15. The method for adjusting discharge power according to claim 1, characterized in that, The feature vector includes a vector consisting of at least one of the following: minimum single-cell voltage, maximum rate of decrease of single-cell voltage, number of cells below the pre-undervoltage threshold, and rate of decrease of state of charge.

16. The method for adjusting discharge power according to claim 15, characterized in that, The preset operating conditions include the initial pre-undervoltage operating condition, the middle pre-undervoltage operating condition, the final pre-undervoltage operating condition, and other operating conditions; Wherein, the initial pre-undervoltage condition characterizes the minimum single-cell voltage as greater than the first voltage, and / or the maximum rate of decrease of the single-cell voltage as greater than the first rate, and / or the number of single-cell cells below the pre-undervoltage voltage threshold as less than the first number, and / or the rate of decrease of the state of charge as greater than the second rate. The pre-undervoltage mid-term operating condition characterizes the minimum single-cell voltage as less than or equal to the first voltage and greater than the second voltage, and / or the maximum rate of decrease of the single-cell voltage as less than or equal to the first rate and greater than the third rate, and / or the number of single-cell cells below the pre-undervoltage voltage threshold as greater than or equal to the first number and less than the second number, and / or the rate of decrease of the state of charge as less than or equal to the second rate and greater than the fourth rate. The pre-undervoltage end-of-life condition characterizes the minimum single-cell voltage as less than or equal to the second voltage, and / or the maximum rate of decrease of the single-cell voltage as less than or equal to the third rate, and / or the number of single-cell cells below the pre-undervoltage threshold as greater than or equal to the second number, and / or the rate of decrease of the state of charge as less than or equal to the fourth rate. Wherein, the first voltage is greater than the second voltage, the first rate is greater than the third rate, the first number is less than the second number, and the second rate is greater than the fourth rate.

17. The method for adjusting discharge power according to claim 16, characterized in that, The power reduction ratio corresponding to the initial pre-undervoltage condition is greater than the power reduction ratio corresponding to the mid-pre-undervoltage condition, the power reduction ratio corresponding to the mid-pre-undervoltage condition is greater than the power reduction ratio corresponding to the final pre-undervoltage condition, and the power reduction ratio corresponding to the other conditions is less than the power reduction ratio corresponding to the initial pre-undervoltage condition but greater than the power reduction ratio corresponding to the mid-pre-undervoltage condition.

18. A discharge power adjustment device, characterized in that, The device includes: The extraction module is used to obtain the current operating parameters of the power battery. In response to the minimum single cell voltage being less than the pre-undervoltage threshold, the module performs feature extraction on the current operating parameters to obtain the feature vector of the current operating condition. The determination module is used to determine the degree of conformity between the current working condition and at least one of the preset working conditions based on the distance between the feature vector of the current working condition and the cluster centers of multiple preset working conditions. The adjustment module is used to determine a target power reduction ratio based on the compliance level and the power reduction ratio corresponding to the preset operating condition, and to adjust the discharge power based on the target power reduction ratio.

19. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the discharge power adjustment method according to any one of claims 1-17.

20. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a processor, implements the steps of the discharge power adjustment method according to any one of claims 1-17.

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